Three classes of glucocerebrosidase inhibitors identified by quantitative high-throughput screening are chaperone leads for Gaucher disease

PubMed Central

Zheng, Wei; Padia, Janak; Urban, Daniel J.; Jadhav, Ajit; Goker-Alpan, Ozlem; Simeonov, Anton; Goldin, Ehud; Auld, Douglas; LaMarca, Mary E.; Inglese, James; Austin, Christopher P.; Sidransky, Ellen

2007-01-01

Gaucher disease is an autosomal recessive lysosomal storage disorder caused by mutations in the glucocerebrosidase gene. Missense mutations result in reduced enzyme activity that may be due to misfolding, raising the possibility of small-molecule chaperone correction of the defect. Screening large compound libraries by quantitative high-throughput screening (qHTS) provides comprehensive information on the potency, efficacy, and structure–activity relationships (SAR) of active compounds directly from the primary screen, facilitating identification of leads for medicinal chemistry optimization. We used qHTS to rapidly identify three structural series of potent, selective, nonsugar glucocerebrosidase inhibitors. The three structural classes had excellent potencies and efficacies and, importantly, high selectivity against closely related hydrolases. Preliminary SAR data were used to select compounds with high activity in both enzyme and cell-based assays. Compounds from two of these structural series increased N370S mutant glucocerebrosidase activity by 40–90% in patient cell lines and enhanced lysosomal colocalization, indicating chaperone activity. These small molecules have potential as leads for chaperone therapy for Gaucher disease, and this paradigm promises to accelerate the development of leads for other rare genetic disorders. PMID:17670938

Synthesis, hydrolysis rates, supercomputer modeling, and antibacterial activity of bicyclic tetrahydropyridazinones.

PubMed

Jungheim, L N; Boyd, D B; Indelicato, J M; Pasini, C E; Preston, D A; Alborn, W E

1991-05-01

Bicyclic tetrahydropyridazinones, such as 13, where X are strongly electron-withdrawing groups, were synthesized to investigate their antibacterial activity. These delta-lactams are homologues of bicyclic pyrazolidinones 15, which were the first non-beta-lactam containing compounds reported to bind to penicillin-binding proteins (PBPs). The delta-lactam compounds exhibit poor antibacterial activity despite having reactivity comparable to the gamma-lactams. Molecular modeling based on semiempirical molecular orbital calculations on a Cray X-MP supercomputer, predicted that the reason for the inactivity is steric bulk hindering high affinity of the compounds to PBPs, as well as high conformational flexibility of the tetrahydropyridazinone ring hampering effective alignment of the molecule in the active site. Subsequent PBP binding experiments confirmed that this class of compound does not bind to PBPs.

The influence of interactions among phenolic compounds on the antiradical activity of chokeberries (Aronia melanocarpa).

PubMed

Jakobek, Lidija; Seruga, Marijan; Krivak, Petra

2011-06-01

In the present work, interactions between phenolic compounds from chokeberries and their influence on the antiradical activity was studied. Three fractions were isolated from chokeberries containing different classes of phenolic compounds. The first fraction contained a major part of phenolic acids and flavonols, the second anthocyanins, and the third insoluble phenols and proanthocyanidins. The phenolic compound content was determined using high-performance liquid chromatography, and the antiradical activity using the DPPH test. In order to evaluate the effects of interactions between phenolic compounds on the antiradical activity, the antiradical activity of individual phenolic fractions was compared with that obtained by mixing phenolic fractions. Phenolic mixtures showed the decrease in the antiradical activity in comparison with the individual phenolic fractions. These results suggest the existence of complex interactions among phenolic compounds that caused the decrease of the antiradical activity. Interactions among chokeberry phenols promoted a negative synergism.

Identification and characterization of biopesticides from Acorus Tatarinowii and A. Calamus

USDA-ARS?s Scientific Manuscript database

Acorus species are rich in secondary compounds and possess high contents of essential oils in their rhizomes. Here we report the isolation, characterization and antifungal activity of eleven compounds from A. tatarinowii Schott. and A. calamus Linn. Five of the compounds had weak antifungal activity...

Abietane-Type Diterpenoid Amides with Highly Potent and Selective Activity against Leishmania donovani and Trypanosoma cruzi.

PubMed

Pirttimaa, Minni; Nasereddin, Abedelmajeed; Kopelyanskiy, Dmitry; Kaiser, Marcel; Yli-Kauhaluoma, Jari; Oksman-Caldentey, Kirsi-Marja; Brun, Reto; Jaffe, Charles L; Moreira, Vânia M; Alakurtti, Sami

2016-02-26

Dehydroabietylamine (1) was used as a starting material to synthesize a small library of dehydroabietyl amides by simple and facile methods, and their activities against two disease-causing trypanosomatids, namely, Leishmania donovani and Trypanosoma cruzi, were assayed. The most potent compound, 10, an amide of dehydroabietylamine and acrylic acid, was found to be highly potent against these parasites, displaying an IC50 value of 0.37 μM against L. donovani axenic amastigotes and an outstanding selectivity index of 63. Moreover, compound 10 fully inhibited the growth of intracellular amastigotes in Leishmania donovani-infected human macrophages with a low IC50 value of 0.06 μM. This compound was also highly effective against T. cruzi amastigotes residing in L6 cells with an IC50 value of 0.6 μM and high selectivity index of 58, being 3.5 times more potent than the reference compound benznidazole. The potent activity of this compound and its relatively low cytotoxicity make it attractive for further development in pursuit of better drugs for patients suffering from leishmaniasis and Chagas disease.

Effects of high hydrostatic pressure and thermal processing on bioactive compounds, antioxidant activity, and volatile profile of mulberry juice.

PubMed

Wang, Fan; Du, Bao-Lei; Cui, Zheng-Wei; Xu, Li-Ping; Li, Chun-Yang

2017-03-01

The aim of this study was to investigate the effects of high hydrostatic pressure and thermal processing on microbiological quality, bioactive compounds, antioxidant activity, and volatile profile of mulberry juice. High hydrostatic pressure processing at 500 MPa for 10 min reduced the total viable count from 4.38 log cfu/ml to nondetectable level and completely inactivated yeasts and molds in raw mulberry juice, ensuring the microbiological safety as thermal processing at 85 ℃ for 15 min. High hydrostatic pressure processing maintained significantly (p < 0.05) higher contents of total phenolic, total flavonoid and resveratrol, and antioxidant activity of mulberry juice than thermal processing. The main volatile compounds of mulberry juice were aldehydes, alcohols, and ketones. High hydrostatic pressure processing enhanced the volatile compound concentrations of mulberry juice while thermal processing reduced them in comparison with the control. These results suggested that high hydrostatic pressure processing could be an alternative to conventional thermal processing for production of high-quality mulberry juice.

Enhanced HTS hit selection via a local hit rate analysis.

PubMed

Posner, Bruce A; Xi, Hualin; Mills, James E J

2009-10-01

The postprocessing of high-throughput screening (HTS) results is complicated by the occurrence of false positives (inactive compounds misidentified as active by the primary screen) and false negatives (active compounds misidentified as inactive by the primary screen). An activity cutoff is frequently used to select "active" compounds from HTS data; however, this approach is insensitive to both false positives and false negatives. An alternative method that can minimize the occurrence of these artifacts will increase the efficiency of hit selection and therefore lead discovery. In this work, rather than merely using the activity of a given compound, we look at the presence and absence of activity among all compounds in its "chemical space neighborhood" to give a degree of confidence in its activity. We demonstrate that this local hit rate (LHR) analysis method outperforms hit selection based on ranking by primary screen activity values across ten diverse high throughput screens, spanning both cell-based and biochemical assay formats of varying biology and robustness. On average, the local hit rate analysis method was approximately 2.3-fold and approximately 1.3-fold more effective in identifying active compounds and active chemical series, respectively, than selection based on primary activity alone. Moreover, when applied to finding false negatives, this method was 2.3-fold better than ranking by primary activity alone. In most cases, novel hit series were identified that would have otherwise been missed. Additional uses of and observations regarding this HTS analysis approach are also discussed.

Synthesis, antimalarial activity, heme binding and docking studies of N-substituted 4-aminoquinoline-pyrimidine molecular hybrids.

PubMed

Maurya, Shiv Shyam; Khan, Shabana I; Bahuguna, Aparna; Kumar, Deepak; Rawat, Diwan S

2017-03-31

A series of novel N-substituted 4-aminoquinoline-pyrimidine hybrids have been synthesized via simple and economic route and evaluated for their antimalarial activity. Most compounds showed potent antimalarial activity against both CQ-sensitive and CQ-resistant strains with high selectivity index. All the compounds were found to be non-toxic to the mammalian cell lines. The most active compound 7b was analysed for heme binding activity using UV-spectrophotometer. Compound was found to interact with heme and a complex formation between compound and heme in a 1:1 stoichiometry ratio was determined using job plots. The interaction of these hybrids was also investigated by the molecular docking studies in the binding site of wild type Pf-DHFR-TS and quadruple mutant Pf-DHFR-TS. The pharmacokinetic property analysis of best active compounds was also studied by ADMET prediction. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Isolation, Separation, and Preconcentration of Biologically Active Compounds from Plant Matrices by Extraction Techniques.

PubMed

Raks, Victoria; Al-Suod, Hossam; Buszewski, Bogusław

2018-01-01

Development of efficient methods for isolation and separation of biologically active compounds remains an important challenge for researchers. Designing systems such as organomineral composite materials that allow extraction of a wide range of biologically active compounds, acting as broad-utility solid-phase extraction agents, remains an important and necessary task. Selective sorbents can be easily used for highly selective and reliable extraction of specific components present in complex matrices. Herein, state-of-the-art approaches for selective isolation, preconcentration, and separation of biologically active compounds from a range of matrices are discussed. Primary focus is given to novel extraction methods for some biologically active compounds including cyclic polyols, flavonoids, and oligosaccharides from plants. In addition, application of silica-, carbon-, and polymer-based solid-phase extraction adsorbents and membrane extraction for selective separation of these compounds is discussed. Potential separation process interactions are recommended; their understanding is of utmost importance for the creation of optimal conditions to extract biologically active compounds including those with estrogenic properties.

C-Aryl glucoside SGLT2 inhibitors containing a biphenyl motif as potential anti-diabetic agents.

PubMed

Ding, Yuyang; Mao, Liufeng; Xu, Dengfeng; Xie, Hui; Yang, Ling; Xu, Hongjiang; Geng, Wenjun; Gao, Yong; Xia, Chunguang; Zhang, Xiquan; Meng, Qingyi; Wu, Donghai; Zhao, Junling; Hu, Wenhui

2015-07-15

A series of highly active C-aryl glucoside SGLT2 inhibitors containing a biphenyl motif were designed and synthesized for biological evaluation. Among the compounds tested, compound 16l demonstrated high inhibitory activity against SGLT2 (IC50=1.9 nM) with an excellent pharmacokinetic profile. Further study indicated that the in vivo efficacy of compound 16l was comparable to that of dapagliflozin, suggesting that further development would be worthwhile. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identifying relationships between unrelated pharmaceutical target proteins on the basis of shared active compounds.

PubMed

Miljković, Filip; Kunimoto, Ryo; Bajorath, Jürgen

2017-08-01

Computational exploration of small-molecule-based relationships between target proteins from different families. Target annotations of drugs and other bioactive compounds were systematically analyzed on the basis of high-confidence activity data. A total of 286 novel chemical links were established between distantly related or unrelated target proteins. These relationships involved a total of 1859 bioactive compounds including 147 drugs and 141 targets. Computational analysis of large amounts of compounds and activity data has revealed unexpected relationships between diverse target proteins on the basis of compounds they share. These relationships are relevant for drug discovery efforts. Target pairs that we have identified and associated compound information are made freely available.

Virtual screening and rational drug design method using structure generation system based on 3D-QSAR and docking.

PubMed

Chen, H F; Dong, X C; Zen, B S; Gao, K; Yuan, S G; Panaye, A; Doucet, J P; Fan, B T

2003-08-01

An efficient virtual and rational drug design method is presented. It combines virtual bioactive compound generation with 3D-QSAR model and docking. Using this method, it is possible to generate a lot of highly diverse molecules and find virtual active lead compounds. The method was validated by the study of a set of anti-tumor drugs. With the constraints of pharmacophore obtained by DISCO implemented in SYBYL 6.8, 97 virtual bioactive compounds were generated, and their anti-tumor activities were predicted by CoMFA. Eight structures with high activity were selected and screened by the 3D-QSAR model. The most active generated structure was further investigated by modifying its structure in order to increase the activity. A comparative docking study with telomeric receptor was carried out, and the results showed that the generated structures could form more stable complexes with receptor than the reference compound selected from experimental data. This investigation showed that the proposed method was a feasible way for rational drug design with high screening efficiency.

Biological evaluation of certain substituted hydantoins and benzalhydantoins against microbes

NASA Astrophysics Data System (ADS)

Hidayat, Ika-Wiani; Thu, Yee Yee; Black, David St. C.; Read, Roger W.

2016-02-01

Twenty-three synthetic (thio)hydantoins and benzalhydantoins were evaluated for antimicrobial activity against Candida albicans, Malassezia furfur, Escherichia coli and Staphylococcus aureus, by the paper disc diffusion method. 3-n-butyl-4'-nitrobenzalhydantoin showed very high activity against E. coli and high selectivity with respect to the other microorganisms, while 3-n-butyl-2'-bromo-4',5'-dimethoxybenzal hydantoin demonstrated very high selectivity in its activity against M. furfur and S. aureus. These compounds show the most promise as drug lead compounds.

Systems and methods for solar energy storage, transportation, and conversion utilizing photochemically active organometallic isomeric compounds and solid-state catalysts

DOEpatents

Vollhardt, K. Peter C.; Segalman, Rachel A; Majumdar, Arunava; Meier, Steven

2015-02-10

A system for converting solar energy to chemical energy, and, subsequently, to thermal energy includes a light-harvesting station, a storage station, and a thermal energy release station. The system may include additional stations for converting the released thermal energy to other energy forms, e.g., to electrical energy and mechanical work. At the light-harvesting station, a photochemically active first organometallic compound, e.g., a fulvalenyl diruthenium complex, is exposed to light and is photochemically converted to a second, higher-energy organometallic compound, which is then transported to a storage station. At the storage station, the high-energy organometallic compound is stored for a desired time and/or is transported to a desired location for thermal energy release. At the thermal energy release station, the high-energy organometallic compound is catalytically converted back to the photochemically active organometallic compound by an exothermic process, while the released thermal energy is captured for subsequent use.

Organoelement chemistry: promising growth areas and challenges

NASA Astrophysics Data System (ADS)

Abakumov, G. A.; Piskunov, A. V.; Cherkasov, V. K.; Fedushkin, I. L.; Ananikov, V. P.; Eremin, D. B.; Gordeev, E. G.; Beletskaya, I. P.; Averin, A. D.; Bochkarev, M. N.; Trifonov, A. A.; Dzhemilev, U. M.; D'yakonov, V. A.; Egorov, M. P.; Vereshchagin, A. N.; Syroeshkin, M. A.; Jouikov, V. V.; Muzafarov, A. M.; Anisimov, A. A.; Arzumanyan, A. V.; Kononevich, Yu N.; Temnikov, M. N.; Sinyashin, O. G.; Budnikova, Yu H.; Burilov, A. R.; Karasik, A. A.; Mironov, V. F.; Storozhenko, P. A.; Shcherbakova, G. I.; Trofimov, B. A.; Amosova, S. V.; Gusarova, N. K.; Potapov, V. A.; Shur, V. B.; Burlakov, V. V.; Bogdanov, V. S.; Andreev, M. V.

2018-05-01

The chemistry of organoelement compounds is now one of the most rapidly developing fields of research, regarding both fundamental science and solution of applied problems. This review covers a variety of classes of organoelement compounds, ranging from molecules with highly labile carbon–element bonds to compounds with stable bonds that form the basis of novel structural materials and demonstrates their role in scientific research and industrial production. The use of Grignard reagents in modern organic synthesis and application of catalytic cyclomagnesiation and cycloalumination reactions for the preparation of difficult-to-access metallacycles are considered. The electron transfer processes in redox-active derivatives of Group 14 elements and the role of radical ions in these processes are discussed. Considerable attention is paid to organometallic compounds, first of all, as catalysts; the dynamic nature of catalysis with these compounds is noted. Unusual strained metallacycles of high thermal stability, zirconacyclocumulenes, which also exhibit catalytic activity, are described. Complexes with redox-active ligands that substantially affect the reactivity of the metal centre and directly participate in reactions with various substrates as well as organometallic compounds of lanthanides are considered. Modern environmentally benign methods for the synthesis of organosilicon compounds and production of unique materials based on them are discussed. Particular Sections are devoted to organophosphorus compounds, including those exhibiting therapeutic properties and possessing unusual optical characteristics, and organic chalcogen compounds, which find use as ligands and biologically active molecules. The bibliography includes 1045 references.

A Rational Design, Synthesis, Biological Evaluation and Structure--Activity Relationship Study of Novel Inhibitors against Cyanobacterial Fructose-1,6-bisphosphate Aldolase.

PubMed

Han, Xinya; Zhu, Xiuyun; Zhu, Shuaihua; Wei, Lin; Hong, Zongqin; Guo, Li; Chen, Haifeng; Chi, Bo; Liu, Yan; Feng, Lingling; Ren, Yanliang; Wan, Jian

2016-01-25

In the present study, a series of novel maleimide derivatives were rationally designed and optimized, and their inhibitory activities against cyanobacteria class-II fructose-1,6-bisphosphate aldolase (Cy-FBA-II) and Synechocystis sp. PCC 6803 were further evaluated. The experimental results showed that the introduction of a bigger group (Br, Cl, CH3, or C6H3-o-F) on the pyrrole-2',5'-dione ring resulted in a decrease in the Cy-FBA-II inhibitory activity of the hit compounds. Generally, most of the hit compounds with high Cy-FBA-II inhibitory activities could also exhibit high in vivo activities against Synechocystis sp. PCC 6803. Especially, compound 10 not only shows a high Cy-FBA-II activity (IC50 = 1.7 μM) but also has the highest in vivo activity against Synechocystis sp. PCC 6803 (EC50 = 0.6 ppm). Thus, compound 10 was selected as a representative molecule, and its probable interactions with the surrounding important residues in the active site of Cy-FBA-II were elucidated by the joint use of molecular docking, molecular dynamics simulations, ONIOM calculations, and enzymatic assays to provide new insight into the binding mode of the inhibitors and Cy-FBA-II. The positive results indicate that the design strategy used in the present study is very likely to be a promising way to find novel lead compounds with high inhibitory activities against Cy-FBA-II in the future. The enzymatic and algal inhibition assays suggest that Cy-FBA-II is very likely to be a promising target for the design, synthesis, and development of novel specific algicides to solve cyanobacterial harmful algal blooms.

Robust Classification of Small-Molecule Mechanism of Action Using a Minimalist High-Content Microscopy Screen and Multidimensional Phenotypic Trajectory Analysis

PubMed Central

Twarog, Nathaniel R.; Low, Jonathan A.; Currier, Duane G.; Miller, Greg; Chen, Taosheng; Shelat, Anang A.

2016-01-01

Phenotypic screening through high-content automated microscopy is a powerful tool for evaluating the mechanism of action of candidate therapeutics. Despite more than a decade of development, however, high content assays have yielded mixed results, identifying robust phenotypes in only a small subset of compound classes. This has led to a combinatorial explosion of assay techniques, analyzing cellular phenotypes across dozens of assays with hundreds of measurements. Here, using a minimalist three-stain assay and only 23 basic cellular measurements, we developed an analytical approach that leverages informative dimensions extracted by linear discriminant analysis to evaluate similarity between the phenotypic trajectories of different compounds in response to a range of doses. This method enabled us to visualize biologically-interpretable phenotypic tracks populated by compounds of similar mechanism of action, cluster compounds according to phenotypic similarity, and classify novel compounds by comparing them to phenotypically active exemplars. Hierarchical clustering applied to 154 compounds from over a dozen different mechanistic classes demonstrated tight agreement with published compound mechanism classification. Using 11 phenotypically active mechanism classes, classification was performed on all 154 compounds: 78% were correctly identified as belonging to one of the 11 exemplar classes or to a different unspecified class, with accuracy increasing to 89% when less phenotypically active compounds were excluded. Importantly, several apparent clustering and classification failures, including rigosertib and 5-fluoro-2’-deoxycytidine, instead revealed more complex mechanisms or off-target effects verified by more recent publications. These results show that a simple, easily replicated, minimalist high-content assay can reveal subtle variations in the cellular phenotype induced by compounds and can correctly predict mechanism of action, as long as the appropriate analytical tools are used. PMID:26886014

Robust Classification of Small-Molecule Mechanism of Action Using a Minimalist High-Content Microscopy Screen and Multidimensional Phenotypic Trajectory Analysis.

PubMed

Twarog, Nathaniel R; Low, Jonathan A; Currier, Duane G; Miller, Greg; Chen, Taosheng; Shelat, Anang A

2016-01-01

Phenotypic screening through high-content automated microscopy is a powerful tool for evaluating the mechanism of action of candidate therapeutics. Despite more than a decade of development, however, high content assays have yielded mixed results, identifying robust phenotypes in only a small subset of compound classes. This has led to a combinatorial explosion of assay techniques, analyzing cellular phenotypes across dozens of assays with hundreds of measurements. Here, using a minimalist three-stain assay and only 23 basic cellular measurements, we developed an analytical approach that leverages informative dimensions extracted by linear discriminant analysis to evaluate similarity between the phenotypic trajectories of different compounds in response to a range of doses. This method enabled us to visualize biologically-interpretable phenotypic tracks populated by compounds of similar mechanism of action, cluster compounds according to phenotypic similarity, and classify novel compounds by comparing them to phenotypically active exemplars. Hierarchical clustering applied to 154 compounds from over a dozen different mechanistic classes demonstrated tight agreement with published compound mechanism classification. Using 11 phenotypically active mechanism classes, classification was performed on all 154 compounds: 78% were correctly identified as belonging to one of the 11 exemplar classes or to a different unspecified class, with accuracy increasing to 89% when less phenotypically active compounds were excluded. Importantly, several apparent clustering and classification failures, including rigosertib and 5-fluoro-2'-deoxycytidine, instead revealed more complex mechanisms or off-target effects verified by more recent publications. These results show that a simple, easily replicated, minimalist high-content assay can reveal subtle variations in the cellular phenotype induced by compounds and can correctly predict mechanism of action, as long as the appropriate analytical tools are used.

Rapid profiling of antimicrobial compounds characterising B. subtilis TR50 cell-free filtrate by high-performance liquid chromatography coupled to high-resolution Orbitrap™ mass spectrometry.

PubMed

Monaci, Linda; Quintieri, Laura; Caputo, Leonardo; Visconti, Angelo; Baruzzi, Federico

2016-01-15

Several Bacillus strains, typically isolated from different food sources, represent renowned producers of a multitude of low and high molecular weight compounds, including lipopeptides and macrolactones, with an importance for their antimicrobial activity. The high homology shared by many of these compounds also occurring as closely related isoforms poses a challenge in their prompt detection. Identification and structural elucidation is generally achieved by matrix-assisted laser desorption/ionization (MALDI) or liquid chromatography (LC) coupled to mass spectrometry (MS) after a pre-fractionation and/or purification step of the extract. In this paper we report the application of a method based on LC separation and high-resolution Orbitrap™-based MS for the rapid screening of raw filtrate of the strain Bacillus subtilis TR50 endowed with antimicrobial activity, without requiring any sample pre-treatment. Upon direct analysis of the cell-free filtrate of Bacillus subtilis TR50 by high-resolution mass spectrometry (HRMS), different compounds families, that proved to exert a remarked antimicrobial activity against several foodborne pathogens, can be readily displayed along the chromatographic run. Among them, three different classes were identified and characterized belonging to the iturin, fengycin and surfactin groups. The high resolving power and accurate mass accuracy provided by the HRMS system in use ensured an enhanced selectivity compared to other mass spectrometers. In addition, after activation of the HCD cell, the HR-MS/MS spectra can provide insights in the structural elucidation of several compounds. The acquisition of HRMS spectra of raw filtrates of subtilis strains allows untargeted analysis of the major classes of compounds produced to be performed, thus facilitating identification of other unknown bioactive molecules after retrospective analysis. These features make this approach a fast tool applicable to the rapid screening and further identification of antimicrobial compounds released by Bacillus strains in raw filtrates. Copyright © 2015 John Wiley & Sons, Ltd.

Comparative phenolic compound profiles and antioxidative activity of the fruit, leaves, and roots of Korean ginseng (Panax ginseng Meyer) according to cultivation years

PubMed Central

Chung, Ill-Min; Lim, Ju-Jin; Ahn, Mun-Seob; Jeong, Haet-Nim; An, Tae-Jin; Kim, Seung-Hyun

2015-01-01

Background The study of phenolic compounds profiles and antioxidative activity in ginseng fruit, leaves, and roots with respect to cultivation years, and has been little reported to date. Hence, this study examined the phenolic compounds profiles and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activities in the fruit, leaves, and roots of Korean ginseng (Panax ginseng Meyer) as a function of cultivation year. Methods Profiling of 23 phenolic compounds in ginseng fruit, leaves, and roots was investigated using ultra-high performance liquid chromatography with the external calibration method. Antioxidative activity of ginseng fruit, leaves, and roots were evaluated using the method of DPPH free-radical-scavenging activity. Results The total phenol content in ginseng fruit and leaves was higher than in ginseng roots (p < 0.05), and the phenol content in the ginseng samples was significantly correlated to the DPPH free-radical-scavenging activity (r = 0.928****). In particular, p-coumaric acid (r = 0.847****) and ferulic acid (r = 0.742****) greatly affected the DPPH activity. Among the 23 phenolic compounds studied, phenolic acids were more abundant in ginseng fruit, leaves, and roots than the flavonoids and other compounds (p < 0.05). In particular, chlorogenic acid, gentisic acid, p- and m-coumaric acid, and rutin were the major phenolic compounds in 3–6-yr-old ginseng fruit, leaves, and roots. Conclusion This study provides basic information about the antioxidative activity and phenolic compounds profiles in fruit, leaves, and roots of Korean ginseng with cultivation years. This information is potentially useful to ginseng growers and industries involved in the production of high-quality and nutritional ginseng products. PMID:26843824

Non-targeted workflow for identification of antimicrobial compounds in animal feed using bioassay-directed screening in combination with liquid chromatography-high resolution mass spectrometry.

PubMed

Wegh, Robin S; Berendsen, Bjorn J A; Driessen-Van Lankveld, Wilma D M; Pikkemaat, Mariël G; Zuidema, Tina; Van Ginkel, Leen A

2017-11-01

A non-targeted workflow is reported for the isolation and identification of antimicrobial active compounds using bioassay-directed screening and LC coupled to high-resolution MS. Suspect samples are extracted using a generic protocol and fractionated using two different LC conditions (A and B). The behaviour of the bioactive compound under these different conditions yields information about the physicochemical properties of the compound and introduces variations in co-eluting compounds in the fractions, which is essential for peak picking and identification. The fractions containing the active compound(s) obtained with conditions A and B are selected using a microbiological effect-based bioassay. The selected bioactive fractions from A and B are analysed using LC combined with high-resolution MS. Selection of relevant signals is automatically carried out by selecting all signals present in both bioactive fractions A and B, yielding tremendous data reduction. The method was assessed using two spiked feed samples and subsequently applied to two feed samples containing an unidentified compound showing microbial growth inhibition. In all cases, the identity of the compound causing microbiological inhibition was successfully confirmed.

Synergetic effect and structure-activity relationship of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors from Crataegus pinnatifida Bge.

PubMed

Ye, Xiao-Li; Huang, Wen-Wen; Chen, Zhu; Li, Xue-Gang; Li, Ping; Lan, Ping; Wang, Liang; Gao, Ying; Zhao, Zhong-Qi; Chen, Xin

2010-03-10

The 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) inhibitors from hawthorn fruit ( Crataegus pinnatifida Bge.) were isolated and evaluated for their antihyperlipidemic effect induced by high-fat diet in mice. After being further purified with silica and polyamide column chromatography from the fractions (fractions A, F, H, and G) with a high inhibitory rate (IR) to HMGR, 24 chromatographic fractions were obtained, including 8 active fractions with a high IR to HMGR. However, the total inhibitory activity of 24 fractions was decreased by about 70%. From eight active fractions, four compounds were obtained by recrystallization and identified as quercetin (a), hyperoside (b), rutin (c), and chlorogenic acid (d), the contents of which in hawthorn EtOH extract were 0.16, 0.32, 1.45, and 0.95%, respectively. The IR values of compounds a-d to HMGR were 6.28, 9.64, 23.53, and 10.56% at the corresponding concentrations of 0.16, 0.32, 1.45, and 0.95 mg/mL, respectively. It was discovered that the IR of a mixture (2.85 mg/mL) matching the original percentage of compounds a-d in hawthorn EtOH extract was up to 79.5%, much higher than that of the single compound and the total IR of these four compounds (50.01%). The in vivo results also revealed that the mixture had a more significant lipid-lowering efficacy than the monomers. Structure-activity relationship revealed the inhibitory activity and lowering-lipid ability of compounds a-c decreased with increasing glycoside numbers. It was concluded that there were synergetic effects on inhibiting HMGR and lowering lipid among compounds a-d, and the weak hydrophilic ability benefits the inhibition to HMGR and lowering-lipid efficacy.

Biosynthetic approaches to creating bioactive fungal metabolites: Pathway engineering and activation of secondary metabolism.

PubMed

Motoyama, Takayuki; Osada, Hiroyuki

2016-12-15

The diversity of natural products is greater than that of combinatorial chemistry compounds and is similar to that of drugs. Compounds rich in sp 3 carbons, such as natural products, typically exhibit high structural complexity and high specificity to molecular targets. Microorganisms can synthesize such sp 3 carbon-rich compounds and can be used as excellent factories for making bioactive compounds. Here, we mainly focus on pathway engineering of two sp 3 carbon-rich bioactive indole alkaloids, fumitremorgin C and terpendole E. We also demonstrate the importance of activation of secondary metabolism by focusing on tenuazonic acid, a bioactive tetramic acid compound, as an example. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design, synthesis, and pharmacological evaluation of a novel series of hormone sensitive lipase inhibitor.

PubMed

Ogiyama, Tomoko; Yamaguchi, Mitsuhiro; Kurikawa, Nobuya; Honzumi, Shoko; Terayama, Koji; Nagaoka, Nobumi; Yamamoto, Yuka; Kimura, Takako; Sugiyama, Daisuke; Inoue, Shin-Ichi

2017-09-01

HSL inhibition is a promising approach to the treatment of dyslipidemia. As a result of re-optimization of lead compound 2, we identified novel compound 25a exhibiting potent inhibitory activity against HSL enzyme and cell with high selectivity for cholinesterases (AChE and BuChE). Reflecting its potent in vitro activity, compound 25a exhibited antilipolytic effect in rats at 1mg/kg p.o., which indicated that this novel compound is the most potent orally active HSL inhibitor. Moreover, compound 25a did not show bioactivation liability. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Coupling of Benzamides and Donor/Acceptor Diazo–Compounds to form γ-Lactams via Rh(III)–Catalyzed C–H Activation

PubMed Central

Hyster, Todd K.; Ruhl, Kyle E.; Rovis, Tomislav

2013-01-01

The coupling of O-pivaloyl benzhydroxamic acids with donor/acceptor diazo compounds provides iso-indolones in high yield. The reaction tolerates a broad range of benzhydroxamic acids and diazo compounds including substituted 2,2,2-trifluorodiazo ethanes. Mechanistic experiments suggest that C–H activation is turnover limiting and irreversible, while insertion of the diazo compound favors electron deficient substrates. PMID:23548055

Facile preparation of bioactive seco-guaianolides and guaianolides from Artemisia gorgonum and evaluation of their phytotoxicity.

PubMed

Macías, Francisco A; Santana, Alejandro; Yamahata, Azusa; Varela, Rosa M; Fronczek, Frank R; Molinillo, José M G

2012-11-26

Commercially available santonin was used to synthesize seven sesquiterpene lactones using a facile strategy that involved a high-yielding photochemical reaction. Three natural products from Artemisia gorgonum were synthesized in good yields, and in the case of two compounds, absolute configurations were determined from X-ray quality crystals. The structures previously reported for these compounds were revised. Sesquiterpene lactones were tested using the etiolated wheat coleoptile bioassay, and the most active compounds were assayed in standard target species. seco-Guaianolide (4) showed higher phytotoxic activities than the known herbicide Logran. This high activity could be due to the presence of a cyclopentenedione ring. These results suggest that compound 4 should be involved in defense of A. gorgorum, displaying a wide range of activities that allow proposing them as new leads for development of a natural herbicide model with a seco-guaianolide skeleton.

Synthesis, evaluation and modeling of some triazolothienopyrimidinones as anti-inflammatory and antimicrobial agents.

PubMed

Bekhit, Adnan A; Farghaly, Ahmed M; Shafik, Ragab M; Elsemary, Mona Ma; El-Shoukrofy, Mai S; Bekhit, Alaa El-Din A; Ibrahim, Tamer M

2017-06-01

New triazolotetrahydrobenzothienopyrimidinone derivatives were synthesized. Their structures were confirmed, and their anti-inflammatory, antimicrobial activities and ulcerogenic potentials were evaluated. Compounds 7a, 10a and 11a showed minimal ulcerogenic effect and high selectivity toward human recombinant COX-2 over COX-1 enzyme with IC 50 values of 1.39, 1.22 and 0.56 μM, respectively. Their docking outcome correlated with their biological activity and confirmed the high selectivity binding toward COX-2. Compound 12b displayed antimicrobial activity comparable to that of ampicillin against Escherichia coli while compounds 6 and 11c were similar to ampicillin against Staphylococcus aureus. In addition, compounds 7a, 9a, 10b and 11c showed dual anti-inflammatory/antimicrobial activities. This work represents a promising matrix for developing new potential anti-inflammatory, antimicrobial and dual antimicrobial/anti-inflammatory candidates. [Formula: see text].

Antifungal and phytotoxic activity of essential oil from root of Senecio amplexicaulis Kunth. (Asteraceae) growing wild in high altitude-Himalayan region.

PubMed

Singh, Rajendra; Ahluwalia, Vivek; Singh, Pratap; Kumar, Naresh; Prakash Sati, Om; Sati, Nitin

2016-08-01

This work was aimed to evaluate the essential oil from root of medicinally important plant Senecio amplexicaulis for chemical composition, antifungal and phytotoxic activity. The chemical composition analysed by GC/GC-MS showed the presence of monoterpene hydrocarbons in high percentage with marker compounds as α-phellandrene (48.57%), o-cymene (16.80%) and β-ocimene (7.61%). The essential oil exhibited significant antifungal activity against five phytopathogenic fungi, Sclerotium rolfsii, Macrophomina phaseolina, Rhizoctonia solani, Pythium debaryanum and Fusarium oxysporum. The oil demonstrated remarkable phytotoxic activity in tested concentration and significant reduction in seed germination percentage of Phalaris minor and Triticum aestivum at higher concentrations. The roots essential oil showed high yield for one of its marker compound (α-phellandrene) which makes it important natural source of this compound.

Hydrodistillation-adsorption method for the isolation of water-soluble, non-soluble and high volatile compounds from plant materials.

PubMed

Mastelić, J; Jerković, I; Blazević, I; Radonić, A; Krstulović, L

2008-08-15

Proposed method of hydrodistillation-adsorption (HDA) on activated carbon and hydrodistillation (HD) with solvent trap were compared for the isolation of water-soluble, non-soluble and high volatile compounds, such as acids, monoterpenes, isothiocyanates and others from carob (Certonia siliqua L.), rosemary (Rosmarinus officinalis L.) and rocket (Eruca sativa L.). Isolated volatiles were analyzed by GC and GC/MS. The main advantages of HDA method over ubiquitous HD method were higher yields of volatile compounds and their simultaneous separation in three fractions that enabled more detail analyses. This method is particularly suitable for the isolation and analysis of the plant volatiles with high amounts of water-soluble compounds. In distinction from previously published adsorption of remaining volatile compounds from distillation water on activated carbon, this method offers simultaneous hydrodistillation and adsorption in the same apparatus.

A High-Throughput Screen Reveals New Small-Molecule Activators and Inhibitors of Pantothenate Kinases

PubMed Central

2016-01-01

Pantothenate kinase (PanK) is a regulatory enzyme that controls coenzyme A (CoA) biosynthesis. The association of PanK with neurodegeneration and diabetes suggests that chemical modifiers of PanK activity may be useful therapeutics. We performed a high throughput screen of >520000 compounds from the St. Jude compound library and identified new potent PanK inhibitors and activators with chemically tractable scaffolds. The HTS identified PanK inhibitors exemplified by the detailed characterization of a tricyclic compound (7) and a preliminary SAR. Biophysical studies reveal that the PanK inhibitor acts by binding to the ATP–enzyme complex. PMID:25569308

Pharmacological effects of primaquine ureas and semicarbazides on the central nervous system in mice and antimalarial activity in vitro.

PubMed

Kedzierska, Ewa; Orzelska, Jolanta; Perković, Ivana; Knežević, Danijel; Fidecka, Sylwia; Kaiser, Marcel; Zorc, Branka

2016-02-01

New primaquine (PQ) urea and semicarbazide derivatives 1-4 were screened for the first time for central nervous system (CNS) and antimalarial activity. Behavioural tests were performed on mice. In vitro cytotoxicity on L-6 cells and activity against erythrocytic stages of Plasmodium falciparum was determined. Compound 4 inhibited 'head-twitch' responses and decreased body temperature of mice, which suggests some involvement of the serotonergic system. Compound 4 protected mice against clonic seizures and was superior in the antimalarial test. A hybrid of two PQ urea 2 showed a strong antimalarial activity, confirming the previous findings of the high activity of bis(8-aminoquinolines) and other bisantimalarial drugs. All the compounds decreased the locomotor activity of mice, what suggests their weak depressive effects on the CNS, while PQ derivatives 1 and 2 increased amphetamine-induced hyperactivity. None of the compounds impaired coordination, what suggests a lack of their neurotoxicity. All the tested compounds presented an antinociceptive activity in the 'writhing' test. Compounds 3 and 4 were active in nociceptive tests, and those effects were reversed by naloxone. Compound 4 could be a useful lead compound in the development of CNS active agents and antimalarials, whereas compound 3 may be considered as the most promising lead for new antinociceptive agents. © 2015 Société Française de Pharmacologie et de Thérapeutique.

Broad activity of diphenyleneiodonium analogues against Mycobacterium tuberculosis, malaria parasites and bacterial pathogens.

PubMed

Nguyen, Nghi; Wilson, Danny W; Nagalingam, Gayathri; Triccas, James A; Schneider, Elena K; Li, Jian; Velkov, Tony; Baell, Jonathan

2018-03-25

In this study, a structure-activity relationship (SAR) compound series based on the NDH-2 inhibitor diphenyleneiodonium (DPI) was synthesised. Compounds were evaluated primarily for in vitro efficacy against Gram-positive and Gram-negative bacteria, commonly responsible for nosocomial and community acquired infections. In addition, we also assessed the activity of these compounds against Mycobacterium tuberculosis (Tuberculosis) and Plasmodium spp. (Malaria). This led to the discovery of highly potent compounds active against bacterial pathogens and malaria parasites in the low nanomolar range, several of which were significantly less toxic to mammalian cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Lecithin:Cholesterol Acyltransferase Activation by Sulfhydryl-Reactive Small Molecules: Role of Cysteine-31

PubMed Central

Freeman, Lita A.; Demosky, Stephen J.; Konaklieva, Monika; Kuskovsky, Rostislav; Aponte, Angel; Ossoli, Alice F.; Gordon, Scott M.; Koby, Ross F.; Manthei, Kelly A.; Shen, Min; Vaisman, Boris L.; Shamburek, Robert D.; Jadhav, Ajit; Calabresi, Laura; Gucek, Marjan; Tesmer, John J.G.; Levine, Rodney L.

2017-01-01

Lecithin:cholesterol acyltransferase (LCAT) catalyzes plasma cholesteryl ester formation and is defective in familial lecithin:cholesterol acyltransferase deficiency (FLD), an autosomal recessive disorder characterized by low high-density lipoprotein, anemia, and renal disease. This study aimed to investigate the mechanism by which compound A [3-(5-(ethylthio)-1,3,4-thiadiazol-2-ylthio)pyrazine-2-carbonitrile], a small heterocyclic amine, activates LCAT. The effect of compound A on LCAT was tested in human plasma and with recombinant LCAT. Mass spectrometry and nuclear magnetic resonance were used to determine compound A adduct formation with LCAT. Molecular modeling was performed to gain insight into the effects of compound A on LCAT structure and activity. Compound A increased LCAT activity in a subset (three of nine) of LCAT mutations to levels comparable to FLD heterozygotes. The site-directed mutation LCAT-Cys31Gly prevented activation by compound A. Substitution of Cys31 with charged residues (Glu, Arg, and Lys) decreased LCAT activity, whereas bulky hydrophobic groups (Trp, Leu, Phe, and Met) increased activity up to 3-fold (P < 0.005). Mass spectrometry of a tryptic digestion of LCAT incubated with compound A revealed a +103.017 m/z adduct on Cys31, consistent with the addition of a single hydrophobic cyanopyrazine ring. Molecular modeling identified potential interactions of compound A near Cys31 and structural changes correlating with enhanced activity. Functional groups important for LCAT activation by compound A were identified by testing compound A derivatives. Finally, sulfhydryl-reactive β-lactams were developed as a new class of LCAT activators. In conclusion, compound A activates LCAT, including some FLD mutations, by forming a hydrophobic adduct with Cys31, thus providing a mechanistic rationale for the design of future LCAT activators. PMID:28576974

A Target-Based High Throughput Screen Yields Trypanosoma brucei Hexokinase Small Molecule Inhibitors with Antiparasitic Activity

PubMed Central

Sharlow, Elizabeth R.; Lyda, Todd A.; Dodson, Heidi C.; Mustata, Gabriela; Morris, Meredith T.; Leimgruber, Stephanie S.; Lee, Kuo-Hsiung; Kashiwada, Yoshiki; Close, David; Lazo, John S.; Morris, James C.

2010-01-01

Background The parasitic protozoan Trypanosoma brucei utilizes glycolysis exclusively for ATP production during infection of the mammalian host. The first step in this metabolic pathway is mediated by hexokinase (TbHK), an enzyme essential to the parasite that transfers the γ-phospho of ATP to a hexose. Here we describe the identification and confirmation of novel small molecule inhibitors of bacterially expressed TbHK1, one of two TbHKs expressed by T. brucei, using a high throughput screening assay. Methodology/Principal Findings Exploiting optimized high throughput screening assay procedures, we interrogated 220,233 unique compounds and identified 239 active compounds from which ten small molecules were further characterized. Computation chemical cluster analyses indicated that six compounds were structurally related while the remaining four compounds were classified as unrelated or singletons. All ten compounds were ∼20-17,000-fold more potent than lonidamine, a previously identified TbHK1 inhibitor. Seven compounds inhibited T. brucei blood stage form parasite growth (0.03≤EC50<3 µM) with parasite specificity of the compounds being demonstrated using insect stage T. brucei parasites, Leishmania promastigotes, and mammalian cell lines. Analysis of two structurally related compounds, ebselen and SID 17387000, revealed that both were mixed inhibitors of TbHK1 with respect to ATP. Additionally, both compounds inhibited parasite lysate-derived HK activity. None of the compounds displayed structural similarity to known hexokinase inhibitors or human African trypanosomiasis therapeutics. Conclusions/Significance The novel chemotypes identified here could represent leads for future therapeutic development against the African trypanosome. PMID:20405000

Anticoagulant activity of marine green and brown algae collected from Jeju Island in Korea.

PubMed

Athukorala, Yasantha; Lee, Ki-Wan; Kim, Se-Kwon; Jeon, You-Jin

2007-07-01

Twenty-two algal species were evaluated for their potential anticoagulant activities. Hot water extracts from selected species, Codium fragile and Sargassum horneri showed high activated partial thromboplastin time (APTT). Ultraflo extract of C. fragile and S. horneri exhibited the most potent anticoagulant activity. Furthermore, in both algal species, active compounds were mainly concentrated in >30kDa faction. The crude polysaccharide fraction (>30kDa; CpoF) of C. fragile composed of approximately 80% carbohydrate and approximately 19% of protein; the crude polysaccharide fraction (>30kDa; CpoF) of S. horneri was composed of 97% of carbohydrate and approximately 2% of protein. Therefore, most probably the active compound, or compounds of the algal species were related to high molecular weight polysaccharide, or a complex form with carbohydrate and protein (proteoglycan).

Antibacterial and cytotoxic activity of isoprenylated coumarin mammea A/AA isolated from Mammea africana.

PubMed

Canning, Corene; Sun, Shi; Ji, Xiangming; Gupta, Smiti; Zhou, Kequan

2013-05-02

The stem bark of Mammea africana is widely distributed in tropical Africa and commonly used in traditional medicine. This study aims to identify the active compound in Mammea africana and to evaluate its antimicrobial and antiproliferative activity. Methanol extract from the bark of the Mammea africana was separated by liquid-liquid extraction, followed by open column chromatography. A principal antimicrobial compound was purified by high performance liquid chromatography (HPLC) and its structure was elucidated by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). The antibacterial activity of the purified compound was determined using the broth microdilution method against 7 common pathogenic bacteria. The compound was also evaluated for cytotoxicity by cell proliferation assay (MTS) using the mouse embryonic fibroblast cell line NIH 3T3 and the non-small cell lung cancer cell line A549. The purified active compound was determined to be mammea A/AA and was found to be highly active against Campylobacter jejuni (MIC=0.5 μg/ml), Streptococcus pneumoniae (MIC=0.25 μg/ml), and Clostridium difficile (MIC=0.25 μg/ml). The compound exhibited significant antiproliferative activities against both NIH 3T3 and A549 cell lines. Mammea A/AA isolated from Mammea africana exerts specific inhibitory activity against Campylobacter jejuni, Streptococcus pneumoniae, and Campylobacter difficile. Mammea A/AA was also found to exhibit significant cytotoxicity against both cancer and normal cell lines. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Bioassay-directed fractionation of organic compounds associated with airborne particulate matter; An interseasonal study

NASA Astrophysics Data System (ADS)

Greenberg, Arthur; Lwo, Jung-Hen; Antherholt, Thomas B.; Rosen, Robert; Hartman, Thomas; Butler, James; Louis, Judy

Bioassay-directed fractionation based upon a modification of a published technique is applied to the study of three seasonal composites of dichloromethane extracts of inhalable particulate matter collected in Newarks, New Jersey The "profiles" of mass distribution and Salmonella TA98 mutagenic activity vs polarity are similar for the three seasons. Only at the second and especially the third fractionation levels are significant differents seen with a slight shift toward more polar compounds during summer. In all three seasons, polar neutral compounds make the greatest contribution toward mutagenic activity. Hydroxynitropolyciclic aromatic hydrocarbons are difficult to analyse by GC/MS) (El and negative chemical ionization), but HPLC/UV appears to be useful. A number of techniques are emplited in the analysis of specific compounds and classes of compounds. Subsequent acetone extraction of filters yields highly polar mutagens where the acidic fractions account for most of the mutagenic activity. These compounds show significantly enhanced mutagenic activity with TA100 relative to TA98 suggesting the presence of highly polar, acidic substances that are strong alkylating agents. The compound 2-acetoxyl-1-nitronaphthalene, found in fresh diesel particalates, is shown to hydrolyse during fractionation, thus introducing a note of caution into the use of such procedures.

Antimicrobial Action of Compounds from Marine Seaweed

PubMed Central

Pérez, María José; Falqué, Elena; Domínguez, Herminia

2016-01-01

Seaweed produces metabolites aiding in the protection against different environmental stresses. These compounds show antiviral, antiprotozoal, antifungal, and antibacterial properties. Macroalgae can be cultured in high volumes and would represent an attractive source of potential compounds useful for unconventional drugs able to control new diseases or multiresistant strains of pathogenic microorganisms. The substances isolated from green, brown and red algae showing potent antimicrobial activity belong to polysaccharides, fatty acids, phlorotannins, pigments, lectins, alkaloids, terpenoids and halogenated compounds. This review presents the major compounds found in macroalga showing antimicrobial activities and their most promising applications. PMID:27005637

Discovery of a novel general anesthetic chemotype using high-throughput screening.

PubMed

McKinstry-Wu, Andrew R; Bu, Weiming; Rai, Ganesha; Lea, Wendy A; Weiser, Brian P; Liang, David F; Simeonov, Anton; Jadhav, Ajit; Maloney, David J; Eckenhoff, Roderic G

2015-02-01

The development of novel anesthetics has historically been a process of combined serendipity and empiricism, with most recent new anesthetics developed via modification of existing anesthetic structures. Using a novel high-throughput screen employing the fluorescent anesthetic 1-aminoanthracene and apoferritin as a surrogate for on-pathway anesthetic protein target(s), we screened a 350,000 compound library for competition with 1-aminoanthracene-apoferritin binding. Hit compounds meeting structural criteria had their binding affinities for apoferritin quantified with isothermal titration calorimetry and were tested for γ-aminobutyric acid type A receptor binding using a flunitrazepam binding assay. Chemotypes with a strong presence in the top 700 and exhibiting activity via isothermal titration calorimetry were selected for medicinal chemistry optimization including testing for anesthetic potency and toxicity in an in vivo Xenopus laevis tadpole assay. Compounds with low toxicity and high potency were tested for anesthetic potency in mice. From an initial chemical library of more than 350,000 compounds, we identified 2,600 compounds that potently inhibited 1-aminoanthracene binding to apoferritin. A subset of compounds chosen by structural criteria (700) was successfully reconfirmed using the initial assay. Based on a strong presence in both the initial and secondary screens the 6-phenylpyridazin-3(2H)-one chemotype was assessed for anesthetic activity in tadpoles. Medicinal chemistry efforts identified four compounds with high potency and low toxicity in tadpoles, two were found to be effective novel anesthetics in mice. The authors demonstrate the first use of a high-throughput screen to successfully identify a novel anesthetic chemotype and show mammalian anesthetic activity for members of that chemotype.

A high-resolution peak fractionation approach for streamlined screening of nuclear-factor-E2-related factor-2 activators in Salvia miltiorrhiza.

PubMed

Zhang, Hui; Luo, Li-Ping; Song, Hui-Peng; Hao, Hai-Ping; Zhou, Ping; Qi, Lian-Wen; Li, Ping; Chen, Jun

2014-01-24

Generation of a high-purity fraction library for efficiently screening active compounds from natural products is challenging because of their chemical diversity and complex matrices. In this work, a strategy combining high-resolution peak fractionation (HRPF) with a cell-based assay was proposed for target screening of bioactive constituents from natural products. In this approach, peak fractionation was conducted under chromatographic conditions optimized for high-resolution separation of the natural product extract. The HRPF approach was automatically performed according to the predefinition of certain peaks based on their retention times from a reference chromatographic profile. The corresponding HRPF database was collected with a parallel mass spectrometer to ensure purity and characterize the structures of compounds in the various fractions. Using this approach, a set of 75 peak fractions on the microgram scale was generated from 4mg of the extract of Salvia miltiorrhiza. After screening by an ARE-luciferase reporter gene assay, 20 diterpene quinones were selected and identified, and 16 of these compounds were reported to possess novel Nrf2 activation activity. Compared with conventional fixed-time interval fractionation, the HRPF approach could significantly improve the efficiency of bioactive compound discovery and facilitate the uncovering of minor active components. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of the key aroma compounds in beef extract using aroma extract dilution analysis.

PubMed

Takakura, Yukiko; Sakamoto, Tomohiro; Hirai, Sachi; Masuzawa, Takuya; Wakabayashi, Hidehiko; Nishimura, Toshihide

2014-05-01

Aroma extract dilution analysis (AEDA) of an ether extract prepared from beef extract (BE) and subsequent identification experiments led to the determination of seven aroma-active compounds in the flavor dilution (FD) factor range of 32-128. Omission experiments to select the most aroma-active compounds from the seven aroma compounds suggested that 2,3,5-trimethyl pyrazine, 1-octen-3-ol, 3-methylbutanoic acid, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone were the main active compounds contributing to the aroma of BE. Aroma recombination, addition, and omission experiments of the four aroma compounds in taste-reconstituted BE showed that each compound had an individual aroma profile. A comparison of the overall aroma between this recombination mixture and BE showed a high similarity, suggesting that the key aroma compounds had been identified successfully. Copyright © 2014 Elsevier Ltd. All rights reserved.

Elucidating compound mechanism of action by network perturbation analysis | Office of Cancer Genomics

Cancer.gov

Genome-wide identification of the mechanism of action (MoA) of small-molecule compounds characterizing their targets, effectors, and activity modulators represents a highly relevant yet elusive goal, with critical implications for assessment of compound efficacy and toxicity. Current approaches are labor intensive and mostly limited to elucidating high-affinity binding target proteins.

Rapid screening, identification, and purification of neuraminidase inhibitors from Lithospermum erythrorhizon Sieb.et Zucc. by ultrafiltration with HPLC-ESI-TOF-MS combined with semipreparative HPLC.

PubMed

Zhang, Minmin; Zhao, Hengqiang; Zhao, Zhiguo; Yan, Huijiao; Lv, Ruimin; Cui, Li; Yuan, Jinpeng; Wang, Daijie; Geng, Yanling; Liu, Daicheng; Wang, Xiao

2016-06-01

We put forward an efficient strategy based on bioassay guidance for the rapid screening, identification, and purification of the neuraminidase inhibitors from traditional Chinese medicines, and apply to the discovery of anti-influenza components from Lithospermiun erythrorhizon Sieb.et Zucc. Ultrafiltration with high-performance liquid chromatography and electrospray ionization time-of-flight mass spectrometry was employed for the rapid screening and preliminarily identification of anti-influenza components from Zicao. Semipreparative high-performance liquid chromatography was used for the rapid separation and purification of the target compounds. NMR spectroscopy, mass spectrometry, and UV spectroscopy were used for further structural identification, and the activity of the compounds was verified by in vitro assay. Five compounds were found to have neuraminidase inhibitory activity by this method. Subsequently, the five compounds were separated by semipreparative high-performance liquid chromatography with the purity over 98% for all of them by high-performance liquid chromatography test. Combined with the NMR spectroscopy, mass spectrometry, and UV spectroscopy data, they were identified as alkannin, acetylalkannin, isobutyrylalkannin, β,β-dimethylacryloylalkannin and isovalerylalkannin. The in vitro assay showed that all five compounds had good neuraminidase inhibitory activities. These results suggested that the method is highly efficient, and it can provide platform and methodology supports for the rapid discovery of anti-influenza active ingredients from complex Chinese herbal medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antibacterial activity of head-to-head bis-benzimidazoles.

PubMed

Moreira, Joao B; Mann, John; Neidle, Stephen; McHugh, Timothy D; Taylor, Peter W

2013-10-01

Symmetric bis-benzimidazole (BBZ) conjugates were profiled for activity against a range of Gram-positive and Gram-negative bacteria. para-Substituted ethoxy, amino and methoxy derivatives displayed potent bacteriostatic activity against meticillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, streptococci and Listeria monocytogenes. Moderate to good activity was also found against mycobacteria; two compounds were strongly active against logarithmic phase and hypoxia-induced latent Mycobacterium tuberculosis. No compound displayed significant activity towards Gram-negative bacteria. Only high concentrations of antibacterial BBZs showed cytotoxic effects towards fibroblasts, and the most active compound was well tolerated by zebrafish embryos. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Discovery of Novel Inhibitors and Fluorescent Probe Targeting NAMPT.

PubMed

Wang, Xia; Xu, Tian-Ying; Liu, Xin-Zhu; Zhang, Sai-Long; Wang, Pei; Li, Zhi-Yong; Guan, Yun-Feng; Wang, Shu-Na; Dong, Guo-Qiang; Zhuo, Shu; Le, Ying-Ying; Sheng, Chun-Quan; Miao, Chao-Yu

2015-07-31

Nicotinamide phosphoribosyltransferase (NAMPT) is a promising antitumor target. Novel NAMPT inhibitors with diverse chemotypes are highly desirable for development of antitumor agents. Using high throughput screening system targeting NAMPT on a chemical library of 30000 small-molecules, we found a non-fluorescent compound F671-0003 and a fluorescent compound M049-0244 with excellent in vitro activity (IC50: 85 nM and 170 nM respectively) and anti-proliferative activity against HepG2 cells. These two compounds significantly depleted cellular NAD levels. Exogenous NMN rescued their anti-proliferative activity against HepG2 cells. Structure-activity relationship study proposed a binding mode for NAMPT inhibitor F671-0003 and highlighted the importance of hydrogen bonding, hydrophobic and π-π interactions in inhibitor binding. Imaging study provided the evidence that fluorescent compound M049-0244 (3 μM) significantly stained living HepG2 cells. Cellular fluorescence was further verified to be NAMPT dependent by using RNA interference and NAMPT over expression transgenic mice. Our findings provide novel antitumor lead compounds and a "first-in-class" fluorescent probe for imaging NAMPT.

In vitro activity of synthetic tetrahydroindeno[2,1-c]quinolines on Leishmania mexicana.

PubMed

Hernández-Chinea, Concepción; Carbajo, Erika; Sojo, Felipe; Arvelo, Francisco; Kouznetsov, Vladimir V; Romero-Bohórquez, Arnold R; Romero, Pedro J

2015-12-01

New synthetic compounds based on tetrahydroindenoquinoline structure were evaluated for their in vitro antileishmanial activities. The seven compounds assayed have antiproliferative activities against promastigotes of Leishmania mexicana. Compound 1 and 3 were the most active (IC50 1.0 μg/ml) and showed high selectivity towards the parasite. These compounds were selected to evaluate their effect on promastigote morphology and mitochondrial transmembrane potential as well as on the amastigote capability to survive into macrophages J774 cell line. Whereas compound 1 affected the promastigote cell cycle, compound 3 induced morphological changes and the total collapse of the mitochondrial transmembrane potential, a hallmark of apoptosis. Both compounds also affected the amastigote form of the parasite, decreasing their survival rate in J774 macrophages. Due to the greatest selectivity index, the apparent effect as apoptotic inducer and its sustained inhibition on intracellular amastigote replication, compound 3 is the best candidate to be tested in vivo. This compound is worth considering for the development of new antileishmanial drugs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Discovery of a novel and potent class of F. tularensis enoyl-reductase (FabI) inhibitors by molecular shape and electrostatic matching

PubMed Central

Hevener, Kirk E.; Mehboob, Shahila; Su, Pin-Chih; Truong, Kent; Boci, Teuta; Deng, Jiangping; Ghassemi, Mahmood; Cook, James L.; Johnson, Michael E.

2011-01-01

Enoyl-acyl carrier protein (ACP) reductase, FabI, is a key enzyme in the bacterial fatty acid biosynthesis pathway (FAS II). FabI is an NADH-dependent oxidoreductase that acts to reduce enoyl-ACP substrates in a final step of the pathway. The absence of this enzyme in humans makes it an attractive target for the development of new antibacterial agents. FabI is known to be unresponsive to structure-based design efforts due to a high degree of induced fit and a mobile flexible loop encompassing the active site. Here we discuss the development, validation, and careful application of a ligand-based virtual screen used for the identification of novel inhibitors of the Francisella tularensis FabI target. In this study, four known classes of FabI inhibitors were used as templates for virtual screens that involved molecular shape and electrostatic matching. The program ROCS was used to search a high-throughput screening library for compounds that matched any of the four molecular shape queries. Matching compounds were further refined using the program EON, which compares and scores compounds by matching electrostatic properties. Using these techniques, 50 compounds were selected, ordered, and tested. The tested compounds possessed novel chemical scaffolds when compared to the input query compounds. Several hits with low micromolar activity were identified and follow-up scaffold-based searches resulted in the identification of a lead series with sub-micromolar enzyme inhibition, high ligand efficiency, and a novel scaffold. Additionally, one of the most active compounds showed promising whole-cell antibacterial activity against several Gram-positive and Gram-negative species, including the target pathogen. The results of a preliminary structure-activity relationship analysis are presented. PMID:22098466

An Overview of Plant Phenolic Compounds and Their Importance in Human Nutrition and Management of Type 2 Diabetes.

PubMed

Lin, Derong; Xiao, Mengshi; Zhao, Jingjing; Li, Zhuohao; Xing, Baoshan; Li, Xindan; Kong, Maozhu; Li, Liangyu; Zhang, Qing; Liu, Yaowen; Chen, Hong; Qin, Wen; Wu, Hejun; Chen, Saiyan

2016-10-15

In this paper, the biosynthesis process of phenolic compounds in plants is summarized, which include the shikimate, pentose phosphate and phenylpropanoid pathways. Plant phenolic compounds can act as antioxidants, structural polymers (lignin), attractants (flavonoids and carotenoids), UV screens (flavonoids), signal compounds (salicylic acid, flavonoids) and defense response chemicals (tannins, phytoalexins). From a human physiological standpoint, phenolic compounds are vital in defense responses, such as anti-aging, anti-inflammatory, antioxidant and anti-proliferative activities. Therefore, it is beneficial to eat such plant foods that have a high antioxidant compound content, which will cut down the incidence of certain chronic diseases, for instance diabetes, cancers and cardiovascular diseases, through the management of oxidative stress. Furthermore, berries and other fruits with low-amylase and high-glucosidase inhibitory activities could be thought of as candidate food items in the control of the early stages of hyperglycemia associated with type 2 diabetes.

Trends and exceptions of physical properties on antibacterial activity for Gram-positive and Gram-negative pathogens.

PubMed

Brown, Dean G; May-Dracka, Tricia L; Gagnon, Moriah M; Tommasi, Ruben

2014-12-11

To better understand the difficulties surrounding the identification of novel antibacterial compounds from corporate screening collections, physical properties of ∼3200 antibacterial project compounds with whole cell activity against Gram-negative or Gram-positive pathogens were profiled and compared to actives found from high throughput (HTS) screens conducted on both biochemical and phenotypic bacterial targets. The output from 23 antibacterial HTS screens illustrated that when compared to the properties of the antibacterial project compounds, the HTS actives were significantly more hydrophobic than antibacterial project compounds (typically 2-4 log units higher), and furthermore, for 14/23 HTS screens, the average clogD was higher than the screening collection average (screening collection clogD = 2.45). It was found that the consequences of this were the following: (a) lead identification programs often further gained hydrophobic character with increased biochemical potency, making the separation even larger between the physicochemical properties of known antibacterial agents and the HTS active starting point, (b) the probability of plasma protein binding and cytotoxicity are often increased, and (c) cell-based activity in Gram-negative bacteria was severely limited or, if present, demonstrated significant efflux. Our analysis illustrated that compounds least susceptible to efflux were those which were highly polar and small in MW or very large and typically zwitterionic. Hydrophobicity was often the dominant driver for HTS actives but, more often than not, precluded whole cell antibacterial activity. However, simply designing polar compounds was not sufficient for antibacterial activity and pointed to a lack of understanding of complex and specific bacterial penetration mechanisms.

Phenolic compounds, organic acids and antioxidant activity of grape juices produced in industrial scale by different processes of maceration.

PubMed

Lima, Marcos dos Santos; da Conceição Prudêncio Dutra, Maria; Toaldo, Isabela Maia; Corrêa, Luiz Claudio; Pereira, Giuliano Elias; de Oliveira, Débora; Bordignon-Luiz, Marilde Terezinha; Ninow, Jorge Luiz

2015-12-01

The effect of maceration process on the profile of phenolic compounds, organic acids composition and antioxidant activity of grape juices from new varieties of Vitis labrusca L. obtained in industrial scale was investigated. The extraction process presented a high yield without pressing the grapes. The use of a commercial pectinase resulted in an increase on extraction yield and procyanidins B1 and B2 concentrations and a decrease on turbidity and concentration of catechins. The combination of 60 °C and 3.0 mL 100 kg(-1) of enzyme resulted in the highest extraction of phenolic compounds, reducing the content of acetic acid. The juices presented high antioxidant activity, related to the great concentration of malvidin, cyanidin, catechin and caffeic, cinnamic and gallic acids. Among the bioactive compounds, the juices presented high concentration of procyanidin B1, caffeic acid and trans-resveratrol, with higher levels compared to those reported in the literature. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Sphingosine 1-phosphate receptor 2 selective allosteric agonist

PubMed Central

Satsu, Hideo; Schaeffer, Marie-Therese; Guerrero, Miguel; Saldana, Adrian; Eberhart, Christina; Hodder, Peter; Cayanan, Charmagne; Schürer, Stephan; Bhhatarai, Barun; Roberts, Ed; Rosen, Hugh; Brown, Steven J.

2013-01-01

Molecular probe tool compounds for the Sphingosine 1-phosphate receptor 2 (S1PR2) are important for investigating the multiple biological processes in which the S1PR2 receptor has been implicated. Amongst these are NF-κB-mediated tumor cell survival and fibroblast chemotaxis to fibronectin. Here we report our efforts to identify selective chemical probes for S1PR2 and their characterization. We employed high throughput screening to identify two compounds which activate the S1PR2 receptor. SAR optimization led to compounds with high nanomolar potency. These compounds, XAX-162 and CYM-5520, are highly selective and do not activate other S1P receptors. Binding of CYM-5520 is not competitive with the antagonist JTE-013. Mutation of receptor residues responsible for binding to the zwitterionic headgroup of sphingosine 1-phosphate (S1P) abolishes S1P activation of the receptor, but not activation by CYM-5520. Competitive binding experiments with radiolabeled S1P demonstrate that CYM-5520 is an allosteric agonist and does not displace the native ligand. Computational modeling suggests that CYM-5520 binds lower in the orthosteric binding pocket, and that co-binding with S1P is energetically well tolerated. In summary, we have identified an allosteric S1PR2 selective agonist compound. PMID:23849205

Phenolic compound concentration and antioxidant activities of edible and medicinal mushrooms from Korea.

PubMed

Kim, Min-Young; Seguin, Philippe; Ahn, Joung-Kuk; Kim, Jong-Jin; Chun, Se-Chul; Kim, Eun-Hye; Seo, Su-Hyun; Kang, Eun-Young; Kim, Sun-Lim; Park, Yool-Jin; Ro, Hee-Myong; Chung, Ill-Min

2008-08-27

A study was conducted to determine the content of phenolic compounds and the antioxidative activity of five edible and five medicinal mushrooms commonly cultivated in Korea. Phenolic compounds were analyzed using high performance liquid chromatography, and antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide dismutase activity. A total of 28 phenolic compounds were detected in the mushrooms studied. The average total concentration of phenolic compounds was 326 microg/g, the average being of 174 microg/g in edible mushrooms and 477 microg/g in medicinal mushrooms. The average total flavonoids concentration was 49 microg/g, with averages of 22 and 76 microg/g in edible and medicinal mushrooms, respectively. The DPPH radical scavenging activities ranged between 15 (Pleurotus eryngii) and 70% (Ganoderma lucidum) when reaction time was for 1 min. When reaction time was 30 min, the values ranged between 5 (Pleurotus eryngii) and 78% (Agaricus bisporus). The SOD activity averaged 28% among the 10 mushroom species, averages for edible and medicinal mushrooms being comparable. DPPH activities was significantly correlated (p < 0.01) with total content of phenolic compounds in edible mushrooms, while in medicinal mushrooms there was a significant correlation (p < 0.01) between SOD activity and total concentration of phenolic compounds. Numerous significant positive correlations were observed between phenolic compounds detected and antioxidative potential.

Cinnamoyl compounds as simple molecules that inhibit p300 histone acetyltransferase.

PubMed

Costi, Roberta; Di Santo, Roberto; Artico, Marino; Miele, Gaetano; Valentini, Paola; Novellino, Ettore; Cereseto, Anna

2007-04-19

Cinnamoly compounds 1a-c and 2a-d were designed, synthesized, and in vitro tested as p300 inhibitors. At different degrees, all tested compounds were proven to inactivate p300, particularly, derivative 2c was the most active inhibitor, also showing high specificity for p300 as compared to other histone acetyltransferases. Most notably, 2c showed anti-acetylase activity in mammalian cells. These compounds represent a new class of synthetic inhibitors of p300, characterized by simple chemical structures.

Rh(III)-Catalyzed C-H Activation of Benzoylacetonitriles and Tandem Cyclization with Diazo Compounds to Substituted Benzo[ de]chromenes.

PubMed

Fang, Feifei; Zhang, Chunmei; Zhou, Chaofan; Li, Yazhou; Zhou, Yu; Liu, Hong

2018-04-06

Rh (III)-catalyzed C-H activation of benzoylacetonitriles in coupling with diazo compounds was developed to synthesize diversified substituted benzo[ de]chromenes via a formal (4 + 2) cycloaddition with a diazo compound and subsequent tandem (4 + 2) cycloaddition with another diazo compound. Intriguingly, synthesis of substituted benzo[ de]chromenes and their decarboxylation products could be realized by controlling the reaction conditions. These reactions have a broad range of substrates, moderate to good yields, and high regioselectivity.

Generation of ligand-based pharmacophore model and virtual screening for identification of novel tubulin inhibitors with potent anticancer activity.

PubMed

Chiang, Yi-Kun; Kuo, Ching-Chuan; Wu, Yu-Shan; Chen, Chung-Tong; Coumar, Mohane Selvaraj; Wu, Jian-Sung; Hsieh, Hsing-Pang; Chang, Chi-Yen; Jseng, Huan-Yi; Wu, Ming-Hsine; Leou, Jiun-Shyang; Song, Jen-Shin; Chang, Jang-Yang; Lyu, Ping-Chiang; Chao, Yu-Sheng; Wu, Su-Ying

2009-07-23

A pharmacophore model, Hypo1, was built on the basis of 21 training-set indole compounds with varying levels of antiproliferative activity. Hypo1 possessed important chemical features required for the inhibitors and demonstrated good predictive ability for biological activity, with high correlation coefficients of 0.96 and 0.89 for the training-set and test-set compounds, respectively. Further utilization of the Hypo1 pharmacophore model to screen chemical database in silico led to the identification of four compounds with antiproliferative activity. Among these four compounds, 43 showed potent antiproliferative activity against various cancer cell lines with the strongest inhibition on the proliferation of KB cells (IC(50) = 187 nM). Further biological characterization revealed that 43 effectively inhibited tubulin polymerization and significantly induced cell cycle arrest in G(2)-M phase. In addition, 43 also showed the in vivo-like anticancer effects. To our knowledge, 43 is the most potent antiproliferative compound with antitubulin activity discovered by computer-aided drug design. The chemical novelty of 43 and its anticancer activities make this compound worthy of further lead optimization.

Evaluation of anti-sepsis activity by compounds with high affinity to lipid a from HuanglianJiedu decoction.

PubMed

Xu, Yubin; Guo, Song; Chen, Guirong; Zhang, Mingbo; Zhang, Xu; Dou, Deqiang

2017-12-01

HuanglianJiedu decoction (HJD) is a classic prescription for heat-clearing away and detoxifying, which is used for the clinical treatment of sepsis, due to sepsis refers to the systemic inflammatory response induced by infection in western medicine, and infection belongs to the category of poison-heat syndrome in traditional Chinese medicine. Previous study had elucidated the effective components from HJD with high affinity to lipid A, which can generate the release of pro-inflammatory-cytokines, resulting in sepsis. Now the anti-sepsis activities of these compounds were evaluated. Immunofluorescence, immunohistochemical staining, ELISA and MTT methods were used to evaluated these compounds. Immunofluorescence analysis evaluated the effects of compounds on the binding of FITC-LPS to RAW264.7 cells, and showed the fluorescence intensity was significant attenuated in geniposides, palmatine, baicalin and berberine groups (64 and 128 μg/mL) compared with model group (p < 0.05), which showed these compounds inhibit the combination of LPS with receptor of cells; immunohistochemical staining and ELISA method showed the TLR4 receptor expression, IL-6 and TNF-α levels were significant decreased in the groups treated with compounds, indicating that geniposides, baicalin, palmatine and berberine can play the role of anti-sepsis by inhibiting the expression of TLR4, the releasing of IL-6 and TNF-α; MTT assay showed that palmatine and berberine had a weak effect on cell viability, while others not, indicating that the compounds have protective activity. It could be concluded the high affinity binding between these compounds and lipid A may be an important basis for its anti-LPS activity in vitro.

Synthesis and anti-proliferative activity of fluoro-substituted chalcones.

PubMed

Burmaoglu, Serdar; Algul, Oztekin; Anıl, Derya Aktas; Gobek, Arzu; Duran, Gulay Gulbol; Ersan, Ronak Haj; Duran, Nizami

2016-07-01

A series of novel fluoro-substituted chalcone derivatives have been synthesized. All synthesized compounds were characterized by (1)H nuclear magnetic resonance (NMR), (13)C NMR, and elemental analysis. Their anti-proliferative activities were evaluated against five cancer cells lines, namely, A549, A498, HeLa, A375, and HepG2 using the MTT method. Most of the compounds showed moderate to high activity with IC50 values in the range of 0.029-0.729μM. Of all the synthesized compounds, 10 and 19 exhibited the most potent anti-proliferative activities against cancer cells, and 10 was identified as the most promising compound. Copyright © 2016 Elsevier Ltd. All rights reserved.

In silico discovery and in vitro activity of inhibitors against Mycobacterium tuberculosis 7,8-diaminopelargonic acid synthase (Mtb BioA).

PubMed

Billones, Junie B; Carrillo, Maria Constancia O; Organo, Voltaire G; Sy, Jamie Bernadette A; Clavio, Nina Abigail B; Macalino, Stephani Joy Y; Emnacen, Inno A; Lee, Alexandra P; Ko, Paul Kenny L; Concepcion, Gisela P

2017-01-01

Computer-aided drug discovery and development approaches such as virtual screening, molecular docking, and in silico drug property calculations have been utilized in this effort to discover new lead compounds against tuberculosis. The enzyme 7,8-diaminopelargonic acid aminotransferase (BioA) in Mycobacterium tuberculosis ( Mtb ), primarily involved in the lipid biosynthesis pathway, was chosen as the drug target due to the fact that humans are not capable of synthesizing biotin endogenously. The computational screening of 4.5 million compounds from the Enamine REAL database has ultimately yielded 45 high-scoring, high-affinity compounds with desirable in silico absorption, distribution, metabolism, excretion, and toxicity properties. Seventeen of the 45 compounds were subjected to bioactivity validation using the resazurin microtiter assay. Among the 4 actives, compound 7 (( Z )- N -(2-isopropoxyphenyl)-2-oxo-2-((3-(trifluoromethyl)cyclohexyl)amino)acetimidic acid) displayed inhibitory activity up to 83% at 10 μg/mL concentration against the growth of the Mtb H37Ra strain.

In silico discovery and in vitro activity of inhibitors against Mycobacterium tuberculosis 7,8-diaminopelargonic acid synthase (Mtb BioA)

PubMed Central

Billones, Junie B; Carrillo, Maria Constancia O; Organo, Voltaire G; Sy, Jamie Bernadette A; Clavio, Nina Abigail B; Macalino, Stephani Joy Y; Emnacen, Inno A; Lee, Alexandra P; Ko, Paul Kenny L; Concepcion, Gisela P

2017-01-01

Computer-aided drug discovery and development approaches such as virtual screening, molecular docking, and in silico drug property calculations have been utilized in this effort to discover new lead compounds against tuberculosis. The enzyme 7,8-diaminopelargonic acid aminotransferase (BioA) in Mycobacterium tuberculosis (Mtb), primarily involved in the lipid biosynthesis pathway, was chosen as the drug target due to the fact that humans are not capable of synthesizing biotin endogenously. The computational screening of 4.5 million compounds from the Enamine REAL database has ultimately yielded 45 high-scoring, high-affinity compounds with desirable in silico absorption, distribution, metabolism, excretion, and toxicity properties. Seventeen of the 45 compounds were subjected to bioactivity validation using the resazurin microtiter assay. Among the 4 actives, compound 7 ((Z)-N-(2-isopropoxyphenyl)-2-oxo-2-((3-(trifluoromethyl)cyclohexyl)amino)acetimidic acid) displayed inhibitory activity up to 83% at 10 μg/mL concentration against the growth of the Mtb H37Ra strain. PMID:28280303

Antioxidant and Antiplasmodial Activities of Bergenin and 11-O-Galloylbergenin Isolated from Mallotus philippensis

PubMed Central

Khan, Hamayun; Amin, Hazrat; Ullah, Asad; Saba, Sumbal; Rafique, Jamal; Khan, Khalid; Ahmad, Nasir; Badshah, Syed Lal

2016-01-01

Two important biologically active compounds were isolated from Mallotus philippensis. The isolated compounds were characterized using spectroanalytical techniques and found to be bergenin (1) and 11-O-galloylbergenin (2). The in vitro antioxidant and antiplasmodial activities of the isolated compounds were determined. For the antioxidant potential, three standard analytical protocols, namely, DPPH radical scavenging activity (RSA), reducing power assay (RPA), and total antioxidant capacity (TAC) assay, were adopted. The results showed that compound 2 was found to be more potent antioxidant as compared to 1. Fascinatingly, compound 2 displayed better EC50 results as compared to α-tocopherol while being comparable with ascorbic acid. The antiplasmodial assay data showed that both the compound exhibited good activity against chloroquine sensitive strain of Plasmodium falciparum (D10) and IC50 values were found to be less than 8 μM. The in silico molecular docking analyses were also performed for the determination of binding affinity of the isolated compounds using P. falciparum proteins PfLDH and Pfg27. The results showed that compound 2 has high docking score and binding affinity to both protein receptors as compared to compound 1. The demonstrated biological potentials declared that compound 2 could be the better natural antioxidant and antiplasmodial candidate. PMID:26998192

Accounting Artifacts in High-Throughput Toxicity Assays.

PubMed

Hsieh, Jui-Hua

2016-01-01

Compound activity identification is the primary goal in high-throughput screening (HTS) assays. However, assay artifacts including both systematic (e.g., compound auto-fluorescence) and nonsystematic (e.g., noise) complicate activity interpretation. In addition, other than the traditional potency parameter, half-maximal effect concentration (EC50), additional activity parameters (e.g., point-of-departure, POD) could be derived from HTS data for activity profiling. A data analysis pipeline has been developed to handle the artifacts and to provide compound activity characterization with either binary or continuous metrics. This chapter outlines the steps in the pipeline using Tox21 glucocorticoid receptor (GR) β-lactamase assays, including the formats to identify either agonists or antagonists, as well as the counter-screen assays for identifying artifacts as examples. The steps can be applied to other lower-throughput assays with concentration-response data.

Discovery of imidazo[1,2-b]pyridazine derivatives as IKKbeta inhibitors. Part 1: Hit-to-lead study and structure-activity relationship.

PubMed

Shimizu, Hiroki; Tanaka, Shinji; Toki, Tadashi; Yasumatsu, Isao; Akimoto, Toshihiko; Morishita, Kaoru; Yamasaki, Tomonori; Yasukochi, Takanori; Iimura, Shin

2010-09-01

Imidazo[1,2-b]pyridazine derivatives from high-throughput screening were developed as IKKbeta inhibitors. By the optimization of the 3- and 6-position of imidazo[1,2-b]pyridazine scaffold, cell-free IKKbeta inhibitory activity and TNFalpha inhibitory activity in THP-1 cell increased. Also, these compounds showed high kinase selectivity. The structure-activity relationship was revealed and the interaction model of imidazo[1,2-b]pyridazine compounds with IKKbeta was constructed. Copyright 2010. Published by Elsevier Ltd.

High-throughput screen of drug repurposing library identifies inhibitors of Sarcocystis neurona growth.

PubMed

Bowden, Gregory D; Land, Kirkwood M; O'Connor, Roberta M; Fritz, Heather M

2018-04-01

The apicomplexan parasite Sarcocystis neurona is the primary etiologic agent of equine protozoal myeloencephalitis (EPM), a serious neurologic disease of horses. Many horses in the U.S. are at risk of developing EPM; approximately 50% of all horses in the U.S. have been exposed to S. neurona and treatments for EPM are 60-70% effective. Advancement of treatment requires new technology to identify new drugs for EPM. To address this critical need, we developed, validated, and implemented a high-throughput screen to test 725 FDA-approved compounds from the NIH clinical collections library for anti-S. neurona activity. Our screen identified 18 compounds with confirmed inhibitory activity against S. neurona growth, including compounds active in the nM concentration range. Many identified inhibitory compounds have well-defined mechanisms of action, making them useful tools to study parasite biology in addition to being potential therapeutic agents. In comparing the activity of inhibitory compounds identified by our screen to that of other screens against other apicomplexan parasites, we found that most compounds (15/18; 83%) have activity against one or more related apicomplexans. Interestingly, nearly half (44%; 8/18) of the inhibitory compounds have reported activity against dopamine receptors. We also found that dantrolene, a compound already formulated for horses with a peak plasma concentration of 37.8 ± 12.8 ng/ml after 500 mg dose, inhibits S. neurona parasites at low concentrations (0.065 μM [0.036-0.12; 95% CI] or 21.9 ng/ml [12.1-40.3; 95% CI]). These studies demonstrate the use of a new tool for discovering new chemotherapeutic agents for EPM and potentially providing new reagents to elucidate biologic pathways required for successful S. neurona infection. Copyright © 2018. Published by Elsevier Ltd.

Synthesis of novel fluorinated chalcones derived from 4‧-morpholinoacetophenone and their antiproliferative effects

NASA Astrophysics Data System (ADS)

Kurşun Aktar, Bedriye Seda; Oruç-Emre, Emine Elçin; Demirtaş, Ibrahim; Yaglioglu, Ayse Sahin; Guler, Caglar; Adem, Sevki; Karaküçük Iyidoğan, Ayşegül

2017-12-01

The fluorinated chalcones were synthesized by Claisen-Schmidt condensation between 4‧-morpholineacetophenone and various fluorinated benzaldehydes in the presence of NaOH in methanol. The synthesized compounds [1-7] were evaluated their antiproliferative activity against HeLa and C6 cell lines. Among them, compounds 4 and 5 were determined to have anticancer activity against HeLa cells line (IC50 values of 7.74 and 6.10 μg/mL, respectively). The anticancer activity results were shown that compounds 3, and 6 had inhibitory against C6 cells (IC50 values of 12.80 and 4.16 μg/mL, respectively). The compounds 1 and 2 had high antiproliferative activity with non-cytotoxicity. All of the new compounds, except for compound 4 showed inhibition against the human isozyme hCA I with IC50 in the range of 0.5-1,16 mM. Pyruvate kinase M2 (PKM2) was effectively inhibited by compound 4 with IC50 = 26 μM.

Synthesis and in vitro antiproliferative and antibacterial activity of new thiazolidine-2,4-dione derivatives.

PubMed

Trotsko, Nazar; Przekora, Agata; Zalewska, Justyna; Ginalska, Grażyna; Paneth, Agata; Wujec, Monika

2018-12-01

In our present research, we synthesised new thiazolidine-2,4-diones (12-28). All the newly synthesised compounds were evaluated for antiproliferative and antibacterial activity. Antiproliferative evaluation was carried out using normal human skin fibroblasts and tumour cell lines: A549, HepG2, and MCF-7. The IC 50 values were determined for tested compounds revealing antiproliferative activity. Moreover, safety index (SI) was calculated. Among all tested derivatives, the compound 18 revealed the highest antiproliferative activity against human lung, breast, and liver cancer cells. More importantly, the derivative 18 showed meaningfully lower IC 50 values when compared to the reference substance, irinotecan, and relatively high SI values. Moreover, newly synthesised compounds were screened for the bacteria growth inhibition in vitro. According to our screening results, most active compound was the derivative 18 against Gram-positive bacteria. Therefore, it may be implied that the novel compound 18 appears to be a very promising agent for anticancer treatment.

Synthesis and antimicrobial evaluation of L-phenylalanine-derived C5-substituted rhodanine and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone.

PubMed

Jin, Xin; Zheng, Chang-Ji; Song, Ming-Xia; Wu, Yan; Sun, Liang-Peng; Li, Yin-Jing; Yu, Li-Jun; Piao, Hu-Ri

2012-10-01

Four novel series of compounds, including the l-phenylalanine-derived C5-substituted rhodanine (6a-q, 7a-j) and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone (9a-e, 11a-e) have been designed, synthesized, characterized, and evaluated for their antibacterial activity. Some of these compounds showed significant antibacterial activity against Gram-positive bacterias, especially against the strains of multidrug-resistant clinical isolates, among which compounds 6c-e, 6g, 6i, 6j and 6q exhibiting high levels of antimicrobial activity against Staphylococcus aureus RN4220 with minimum inhibitory concentration (MIC) values of 2 μg/mL. Compound 6q showed the most potent activity of all of the compounds against all of the test multidrug-resistant clinical isolates tested. Unfortunately, however, none of the compounds were active against Gram-negative bacteria at 64 μg/mL. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Rapid screening of transferrin-binders in the flowers of Bauhinia blakeana Dunn by on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-transferrin-fluorescence detection system.

PubMed

Liu, Meixian; Dong, Jing; Lin, Zongtao; Niu, Yanyan; Zhang, Xiaotian; Jiang, Haixiu; Guo, Ning; Li, Wei; Wang, Hong; Chen, Shizhong

2016-06-10

Transferrin (Transferrin, TRF, TF) has drawn increasing attention in cancer therapy due to its potential applications in drug delivery. TF receptor, highly expressed in tumor cells, recognizes and transports Fe(3+)-TF into cells to release iron into cytoplasm. Thus, discovering TF-binding compounds has become an active research area and is of great importance for target therapy. In this study, an on-line analysis method was established for screening TF-binding compounds from the flowers of Bauhinia blakeana Dunn using a high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-transferrin-fluorescence detector (HPLC-DAD-MS(n)-TF-FLD) method. As a result, 33 of 80 identified or tentatively characterized compounds in the sample were TF-binding active. Twenty-five flavonol glycosides and eight phenolic acids were identified as TF-binders. Twelve of these active compounds together with six standard compounds were used to study the dose-response effects and structure-activity relationships of flavonoids and phenolic acids. The method was validated by vitexin with a good linearity in the range of concentrations used in the study. The limit of detection for vitexin was 0.1596 nmol. Our study indicated that the established method is simple, rapid and sensitive for screening TF-binding active compounds in the extract of Bauhinia blakeana Dunn, and therefore is important for discovering potential anti-cancer ingredients from complex samples for TF related drug delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

Medicinal chemistry optimization of antiplasmodial imidazopyridazine hits from high throughput screening of a SoftFocus kinase library: part 1.

PubMed

Le Manach, Claire; Gonzàlez Cabrera, Diego; Douelle, Frederic; Nchinda, Aloysius T; Younis, Yassir; Taylor, Dale; Wiesner, Lubbe; White, Karen L; Ryan, Eileen; March, Corinne; Duffy, Sandra; Avery, Vicky M; Waterson, David; Witty, Michael J; Wittlin, Sergio; Charman, Susan A; Street, Leslie J; Chibale, Kelly

2014-03-27

A novel class of imidazopyridazines identified from whole cell screening of a SoftFocus kinase library was synthesized and evaluated for antiplasmodial activity against K1 (multidrug resistant strain) and NF54 (sensitive strain). Structure-activity relationship studies led to the identification of highly potent compounds against both strains. Compound 35 was highly active (IC50: K1 = 6.3 nM, NF54 = 7.3 nM) and comparable in potency to artesunate, and 35 exhibited 98% activity in the in vivo P. berghei mouse model (4-day test by Peters) at 4 × 50 mg/kg po. Compound 35 was also assessed against P. falciparum in the in vivo SCID mouse model where the efficacy was found to be more consistent with the in vitro activity. Furthermore, 35 displayed high (78%) rat oral bioavailability with good oral exposure and plasma half-life. Mice exposure at the same dose was 10-fold lower than in rat, suggesting lower oral absorption and/or higher metabolic clearance in mice.

Two-electron high potential and high capacity redox active molecules for energy storage applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Jinhua; Zhang, Lu; Burrell, Anthony K.

A non-aqueous redox flow battery includes a catholyte including a compound of formula (I), a compound of formula (II), or a compound of formula (III): ##STR00001## wherein two R groups have the formula X, wherein X is X, wherein X is a group of formula IV-A or IV-B; ##STR00002##

Discovery of a Novel General Anesthetic Chemotype Using High-throughput Screening

PubMed Central

McKinstry-Wu, Andrew R.; Bu, Weiming; Rai, Ganesha; Lea, Wendy A.; Weiser, Brian P.; Liang, David F.; Simeonov, Anton; Jadhav, Ajit; Maloney, David J.; Eckenhoff, Roderic G.

2014-01-01

Background The development of novel anesthetics has historically been a process of combined serendipity and empiricism, with most recent new anesthetics developed via modification of existing anesthetic structures. Methods Using a novel high-throughput screen employing the fluorescent anesthetic 1-aminoanthracene (1-AMA) and apoferritin as a surrogate for on-pathway anesthetic protein target(s), we screened a 350,000 compound library for competition with 1-AMA-apoferritin binding. Hit compounds meeting structural criteria had their binding affinities for apoferritin quantified with isothermal titration calorimetry and were tested for γ-aminobutyric acid type A-receptor binding using a flunitrazepam binding assay. Chemotypes with a strong presence in the top 700 and exhibiting activity via isothermal titration calorimetry were selected for medicinal chemistry optimization including testing for anesthetic potency and toxicity in an in vivo Xenopus laevis tadpole assay. Compounds with low toxicity and high potency were tested for anesthetic potency in mice. Results From an initial chemical library of over 350,000 compounds, we identified 2,600 compounds that potently inhibited 1-AMA binding to apoferritin. A subset of compounds chosen by structural criteria (700) was successfully reconfirmed using the initial assay. Based upon a strong presence in both the initial and secondary screens the 6-phenylpyridazin-3(2H)-one chemotype was assessed for anesthetic activity in tadpoles. Medicinal chemistry efforts identified four compounds with high potency and low toxicity in tadpoles, two were found to be effective novel anesthetics in mice. Conclusions We demonstrate the first use of a high-throughput screen to successfully identify a novel anesthetic chemotype and show mammalian anesthetic activity for members of that chemotype. PMID:25603205

A Virtual Screening Approach For Identifying Plants with Anti H5N1 Neuraminidase Activity

PubMed Central

2016-01-01

Recent outbreaks of highly pathogenic and occasional drug-resistant influenza strains have highlighted the need to develop novel anti-influenza therapeutics. Here, we report computational and experimental efforts to identify influenza neuraminidase inhibitors from among the 3000 natural compounds in the Malaysian-Plants Natural-Product (NADI) database. These 3000 compounds were first docked into the neuraminidase active site. The five plants with the largest number of top predicted ligands were selected for experimental evaluation. Twelve specific compounds isolated from these five plants were shown to inhibit neuraminidase, including two compounds with IC50 values less than 92 μM. Furthermore, four of the 12 isolated compounds had also been identified in the top 100 compounds from the virtual screen. Together, these results suggest an effective new approach for identifying bioactive plant species that will further the identification of new pharmacologically active compounds from diverse natural-product resources. PMID:25555059

Decontamination formulation with sorbent additive

DOEpatents

Tucker; Mark D. , Comstock; Robert H.

2007-10-16

A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator, a sorbent additive, and water. The highly adsorbent, water-soluble sorbent additive (e.g., sorbitol or mannitol) is used to "dry out" one or more liquid ingredients, such as the liquid bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate) and convert the activator into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

Automated recycling of chemistry for virtual screening and library design.

PubMed

Vainio, Mikko J; Kogej, Thierry; Raubacher, Florian

2012-07-23

An early stage drug discovery project needs to identify a number of chemically diverse and attractive compounds. These hit compounds are typically found through high-throughput screening campaigns. The diversity of the chemical libraries used in screening is therefore important. In this study, we describe a virtual high-throughput screening system called Virtual Library. The system automatically "recycles" validated synthetic protocols and available starting materials to generate a large number of virtual compound libraries, and allows for fast searches in the generated libraries using a 2D fingerprint based screening method. Virtual Library links the returned virtual hit compounds back to experimental protocols to quickly assess the synthetic accessibility of the hits. The system can be used as an idea generator for library design to enrich the screening collection and to explore the structure-activity landscape around a specific active compound.

Decoys Selection in Benchmarking Datasets: Overview and Perspectives

PubMed Central

Réau, Manon; Langenfeld, Florent; Zagury, Jean-François; Lagarde, Nathalie; Montes, Matthieu

2018-01-01

Virtual Screening (VS) is designed to prospectively help identifying potential hits, i.e., compounds capable of interacting with a given target and potentially modulate its activity, out of large compound collections. Among the variety of methodologies, it is crucial to select the protocol that is the most adapted to the query/target system under study and that yields the most reliable output. To this aim, the performance of VS methods is commonly evaluated and compared by computing their ability to retrieve active compounds in benchmarking datasets. The benchmarking datasets contain a subset of known active compounds together with a subset of decoys, i.e., assumed non-active molecules. The composition of both the active and the decoy compounds subsets is critical to limit the biases in the evaluation of the VS methods. In this review, we focus on the selection of decoy compounds that has considerably changed over the years, from randomly selected compounds to highly customized or experimentally validated negative compounds. We first outline the evolution of decoys selection in benchmarking databases as well as current benchmarking databases that tend to minimize the introduction of biases, and secondly, we propose recommendations for the selection and the design of benchmarking datasets. PMID:29416509

Design, synthesis, antiviral bioactivity and three-dimensional quantitative structure-activity relationship study of novel ferulic acid ester derivatives containing quinazoline moiety.

PubMed

Wu, Zengxue; Zhang, Jian; Chen, Jixiang; Pan, Jianke; Zhao, Lei; Liu, Dengyue; Zhang, Awei; Chen, Jin; Hu, Deyu; Song, Baoan

2017-10-01

Ferulic acid and quinazoline derivatives possess good antiviral activities. In order to develop novel compounds with high antiviral activities, a series of ferulic acid ester derivatives containing quinazoline were synthesized and evaluated for their antiviral activities. Bioassays indicated that some of the compounds exhibited good antiviral activities in vivo against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). One of the compounds demonstrated significant curative and protective activities against TMV and CMV, with EC 50 values of 162.14, 114.61 and 255.49, 138.81 mg L -1 , respectively, better than those of ningnanmycin (324.51, 168.84 and 373.88, 272.70 mg L -1 ). The values of q 2 and r 2 for comparative molecular field analysis and comparative molecular similarity index analysis in the TMV (0.508, 0.663 and 0.992, 0.930) and CMV (0.530, 0.626 and 0.997, 0.981) models presented good predictive abilities. Some of the title compounds demonstrated good antiviral activities. Three-dimensional quantitative structure-activity relationship models revealed that the antiviral activities depend on steric and electrostatic properties. These results could provide significant structural insights for the design of highly active ferulic acid derivatives. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Metabolite profiling and isolation of biologically active compounds from Scadoxus puniceus, a highly traded South African medicinal plant.

PubMed

Naidoo, Devashan; Slavětínská, Lenka Poštová; Aremu, Adeyemi O; Gruz, Jiri; Biba, Ondrej; Doležal, Karel; Van Staden, Johannes; Finnie, Jeffrey F

2018-04-01

Scadoxus puniceus (Amaryllidaceae), a medicinal plant of high value in South Africa, is used as a component of a traditional herbal tonic prescribed to treat several ailments. Ultra-high performance liquid chromatography-tandem mass spectrometry quantified the phenolic compounds in different organs of S. puniceus. Gravity column chromatography was used to separate fractions and active compounds. The structure of these compounds was determined using 1D and 2D nuclear magnetic resonance and mass spectroscopic techniques. A microplate technique was used to determine the acetylcholinesterase inhibitory activity of the pure compounds. Metabolite profiling revealed a greater profusion of hydroxycinnamic acids (69.5%), as opposed to hydroxybenzoic acids (30.5%). Chlorogenic acid was the most abundant (49.6% of hydroxycinnamic acids) compound. In addition to chlorogenic acid, the study is the first to report the presence of sinapic, gallic, and m-hydroxybenzoic acids in the Amaryllidaceae. Chromatographic separation of S. puniceus led to the isolation of haemanthamine (1), haemanthidine (2), and a rare chlorinated amide, metolachlor (3), the natural occurrence of which is described for the first time. Haemanthamine, haemanthidine, and metolachlor displayed strong acetylcholinesterase inhibitory activity (IC 50 ; 23.1, 23.7, and 11.5 μM, respectively). These results substantiate the frequent use of S. puniceus as a medicinal plant and hold much promise for further pharmaceutical development. Copyright © 2017 John Wiley & Sons, Ltd.

Identification of compounds inhibiting the C-S lyase activity of a cell extract from a Staphylococcus sp. isolated from human skin.

PubMed

Egert, M; Höhne, H-M; Weber, T; Simmering, R; Banowski, B; Breves, R

2013-12-01

The C-S lyase activity of bacteria in the human armpit releases highly malodorous, volatile sulfur compounds from nonvolatile precursor molecules. Such compounds significantly contribute to human body odour. Hence, C-S lyase represents an attractive target for anti-body-odour cosmetic products. Here, aiming at a final use in an ethanol-based deodorant formulation, 267 compounds and compound mixtures were screened for their ability to inhibit the C-S lyase activity of a Stapyhlococcus sp. crude extract. Staphylococcus sp. Isolate 128, closely related to Staphylococcus hominis, was chosen as the test bacterium, as it showed a reproducibly high specific C-S lyase activity on three different culturing media. Using a photometric assay and benzylcysteine as substrate, six rather complex, plant-derived compound mixtures and five well defined chemical compounds or compound mixtures were identified as inhibitors, leading to an inhibition of ≥70% at concentrations of ≤0·5% in the assay. The inhibition data have demonstrated that compounds with two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue are characteristic for the inhibition. The substances identified as C-S lyase inhibitors have the potential to improve the performance of anti-body-odour cosmetic products, for example, ethanol-based deodorants. Bacterial C-S lyase represents one of the key enzymes involved in human body odour formation. The aim of this study was to identify compounds inhibiting the C-S lyase activity of a Staphylococcus sp. isolate from the human skin. The compounds identified as the best inhibitors are characterized by the following features: two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue. They might be used to improve the performance of cosmetic products aiming to prevent the formation of microbially caused human body odour, for example, ethanol-based deodorants. © 2013 The Society for Applied Microbiology.

Ethyl 3-oxo-2-(2,5-dioxopyrrolidin-3-yl)butanoate derivatives: Anthelmintic and cytotoxic potentials, antimicrobial and docking studies

NASA Astrophysics Data System (ADS)

Mahmood, Fawad; Jan, Muhammad S.; Ahmad, Sajjad; Rashid, Umer; Ayaz, Muhammad; Ullah, Farhat; Hussain, Fida; Ahmad, Ashfaq; Khan, Arif-ullah; Aasim, Muhammad; Sadiq, Abdul

2017-12-01

The development of novel and more effective drugs is slow asthe resistance produced by pathogens.From the current scenario it can be imagine that this field of research will enter into the pre-antibiotic era. This work aims to study and evaluate the preliminary antibacterial, anthelmintic and cytotoxic potentials of ethyl 3-oxo-2-(2,5-dioxopyrrolidin-3-yl)butanoates.Among all of the four compounds, compound 2 has displayed remarkable potency with MIC values of 0.125, 0.083, 0.073 and 0.109 mg/ml against E. sakazakii, E. coli. S. aureus and K. pneumonia respectively. Compared to etoposide (LC50 9.8 µg/ml), the compounds demonstrated LC50 values from 280 to 765 µg/ml. For anthelmintic assay, three concentrations of each compound and standard drug were studied in determination of time of death of the two species. Excellent anthelmintic activity was observed by all four compounds against P. posthuma and A. gallibetter than standard albendazole. High GOLD fitness score data from docking analysis towards the targets represent better protein–ligand binding affinity and thus indicate a high propensity for all the active compounds to bind to the active site.Thepromisingin-vitro antimicrobial, anthelmintic activity and cytotoxicity data conclusively revealed that these compounds may serve as viable lead compounds for the treatment of bacterial and parasitic infections, and therefore, could help the medicinal chemists to design future chemotherapeutic agents to avoid rapid drug resistance.

Aroma characterization of tangerine hybrids by gas-chromatography-olfactometry and sensory evaluation.

PubMed

Miyazaki, Takayuki; Plotto, Anne; Baldwin, Elizabeth A; Reyes-De-Corcuera, José I; Gmitter, Fred G

2012-03-15

Tangerines have a distinct flavor among citrus fruit. However, information on tangerine volatiles remains limited. Volatile compounds from a breeding population of tangerines were earlier identified by gas chromatography-mass spectrometry. In this study, five hybrids with a distinct volatile profile were analyzed by gas-chromatography-olfactometry (GC-O) and descriptive sensory analysis. Forty-nine aroma active compounds were found in a consensus by GC-O. Aldehydes were the most important group with odor activity, as well as monoterpenes, esters, alcohols and ketones. 1,8-Cineole, β-myrcene, (E,E)-2,4-nonadienal, hexanal, ethyl-2-methylbutanoate, and linalool were perceived with high intensity in most samples. Two 'Clementine' × 'Minneola' and one 'Fortune' × 'Murcott' hybrids with tangerine, sulfury and woody/spicy flavors had aroma active compounds with terpeney, fatty/vegetable and metallic/rubber descriptors. A tangerine with 'Valencia' orange in its parentage had a characteristic orange flavor, which could be explained by esters and ketones, high in fruity and floral odor intensities. A hybrid of unknown origin had a distinct fruity-non-citrus and pumpkin/fatty flavor; that sample had the lowest amount of aroma-active volatiles, with the least compounds with terpeney odors. There was no one compound characteristic of tangerine flavor. Nevertheless, each sample sensory characteristic could be explained by a set of aroma-active volatile compounds.

Pharmacodynamics of selective androgen receptor modulators.

PubMed

Yin, Donghua; Gao, Wenqing; Kearbey, Jeffrey D; Xu, Huiping; Chung, Kiwon; He, Yali; Marhefka, Craig A; Veverka, Karen A; Miller, Duane D; Dalton, James T

2003-03-01

The present study aimed to identify selective androgen receptor modulators (SARMs) with in vivo pharmacological activity. We examined the in vitro and in vivo pharmacological activity of four chiral, nonsteroidal SARMs synthesized in our laboratories. In the in vitro assays, these compounds demonstrated moderate to high androgen receptor (AR) binding affinity, with K(i) values ranging from 4 to 37 nM, and three of the compounds efficaciously stimulated AR-mediated reporter gene expression. The compounds were then administered subcutaneously to castrated rats to appraise their in vivo pharmacological activity. Androgenic activity was evaluated by the ability of these compounds to maintain the weights of prostate and seminal vesicle, whereas levator ani muscle weight was used as a measure of anabolic activity. The maximal response (E(max)) and dose for half-maximal effect (ED(50)) were determined for each compound and compared with that observed for testosterone propionate (TP). Compounds S-1 and S-4 demonstrated in vivo androgenic and anabolic activity, whereas compounds S-2 and S-3 did not. The activities of S-1 and S-4 were tissue-selective in that both compounds stimulated the anabolic organs more than the androgenic organs. These two compounds were less potent and efficacious than TP in androgenic activity, but their anabolic activity was similar to or greater than that of TP. Neither S-1 nor S-4 caused significant luteinizing hormone or follicle stimulating hormone suppression at doses near the ED(50) value. Thus, compounds S-1 and S-4 were identified as SARMs with potent and tissue-selective in vivo pharmacological activity, and represent the first members of a new class of SARMs with selective anabolic effects.

Design of cinnamaldehyde amino acid Schiff base compounds based on the quantitative structure-activity relationship.

PubMed

Wang, Hui; Jiang, Mingyue; Li, Shujun; Hse, Chung-Yun; Jin, Chunde; Sun, Fangli; Li, Zhuo

2017-09-01

Cinnamaldehyde amino acid Schiff base (CAAS) is a new class of safe, bioactive compounds which could be developed as potential antifungal agents for fungal infections. To design new cinnamaldehyde amino acid Schiff base compounds with high bioactivity, the quantitative structure-activity relationships (QSARs) for CAAS compounds against Aspergillus niger ( A. niger ) and Penicillium citrinum (P. citrinum) were analysed. The QSAR models ( R 2  = 0.9346 for A. niger , R 2  = 0.9590 for P. citrinum, ) were constructed and validated. The models indicated that the molecular polarity and the Max atomic orbital electronic population had a significant effect on antifungal activity. Based on the best QSAR models, two new compounds were designed and synthesized. Antifungal activity tests proved that both of them have great bioactivity against the selected fungi.

Design of cinnamaldehyde amino acid Schiff base compounds based on the quantitative structure–activity relationship

PubMed Central

Wang, Hui; Jiang, Mingyue; Hse, Chung-Yun; Jin, Chunde; Sun, Fangli; Li, Zhuo

2017-01-01

Cinnamaldehyde amino acid Schiff base (CAAS) is a new class of safe, bioactive compounds which could be developed as potential antifungal agents for fungal infections. To design new cinnamaldehyde amino acid Schiff base compounds with high bioactivity, the quantitative structure–activity relationships (QSARs) for CAAS compounds against Aspergillus niger (A. niger) and Penicillium citrinum (P. citrinum) were analysed. The QSAR models (R2 = 0.9346 for A. niger, R2 = 0.9590 for P. citrinum,) were constructed and validated. The models indicated that the molecular polarity and the Max atomic orbital electronic population had a significant effect on antifungal activity. Based on the best QSAR models, two new compounds were designed and synthesized. Antifungal activity tests proved that both of them have great bioactivity against the selected fungi. PMID:28989758

Identification of Phenolic Compounds and Evaluation of Antioxidant and Antimicrobial Properties of Euphorbia Tirucalli L.

PubMed Central

de Araújo, Keline Medeiros; de Lima, Alessandro; Silva, Jurandy do N.; Rodrigues, Larissa L.; Amorim, Adriany G. N.; Quelemes, Patrick V.; dos Santos, Raimunda C.; Rocha, Jefferson A.; de Andrades, Éryka O.; Leite, José Roberto S. A.; Mancini-Filho, Jorge; da Trindade, Reginaldo Almeida

2014-01-01

Bioactive compounds extracted from natural sources can benefit human health. The aim of this work was to determine total phenolic content and antioxidant activity in extracts of Euphorbia tirucalli L. followed by identification and quantification of the phenolic compounds, as well as their antibacterial activities. Antioxidant activities were determined by DPPH and ABTS•+ assay. Identification of phenolic compounds was performed using high-performance liquid chromatography (HPLC), and antimicrobial activities were verified by agar dilution methods and MIC values. Total phenolic content ranged from 7.73 to 30.54 mg/100 g gallic acid equivalent. Extracts from dry plants showed higher antioxidant activities than those from fresh ones. The DPPH EC50 values were approximately 12.15 μg/mL and 16.59 μg/mL, respectively. Antioxidant activity measured by the ABTS method yielded values higher than 718.99 μM trolox/g for dry plants, while by the Rancimat® system yielded protection factors exceeding 1 for all extracts, comparable to synthetic BHT. Ferulic acid was the principal phenolic compound identified and quantified through HPLC-UV in all extracts. The extracts proved effective inhibitory potential for Staphylococcus epidermidis and Staphylococcus aureus. These results showed that extracts of Euphorbia tirucalli L. have excellent antioxidant capacity and moderate antimicrobial activity. These can be attributed to the high concentration of ferulic acid. PMID:26784670

High-throughput testing in head and neck squamous cell carcinoma identifies agents with preferential activity in human papillomavirus-positive or negative cell lines.

PubMed

Ghasemi, Farhad; Black, Morgan; Sun, Ren X; Vizeacoumar, Frederick; Pinto, Nicole; Ruicci, Kara M; Yoo, John; Fung, Kevin; MacNeil, Danielle; Palma, David A; Winquist, Eric; Mymryk, Joe S; Ailles, Laurie A; Datti, Alessandro; Barrett, John W; Boutros, Paul C; Nichols, Anthony C

2018-05-25

Head and neck squamous cell carcinoma (HNSCC) is a common cancer diagnosis worldwide. Despite advances in treatment, HNSCC has very poor survival outcomes, emphasizing an ongoing need for development of improved therapeutic options. The distinct tumor characteristics of human papillomavirus (HPV)-positive vs . HPV-negative disease necessitate development of treatment strategies tailored to tumor HPV-status. High-throughput robotic screening of 1,433 biologically and pharmacologically relevant compounds at a single dose (4 μM) was carried out against 6 HPV-positive and 20 HPV-negative HNSCC cell lines for preliminary identification of therapeutically relevant compounds. Statistical analysis was further carried out to differentiate compounds with preferential activity against cell lines stratified by the HPV-status. These analyses yielded 57 compounds with higher activity in HPV-negative cell lines, and 34 with higher-activity in HPV-positive ones. Multi-point dose-response curves were generated for six of these compounds (Ryuvidine, MK-1775, SNS-032, Flavopiridol, AZD-7762 and ARP-101), confirming Ryuvidine to have preferential potency against HPV-negative cell lines, and MK-1775 to have preferential potency against HPV-positive cell lines. These data comprise a valuable resource for further investigation of compounds with therapeutic potential in the HNSCC.

Cell-Based High-Throughput Screening for Aromatase Inhibitors in the Tox21 10K Library.

PubMed

Chen, Shiuan; Hsieh, Jui-Hua; Huang, Ruili; Sakamuru, Srilatha; Hsin, Li-Yu; Xia, Menghang; Shockley, Keith R; Auerbach, Scott; Kanaya, Noriko; Lu, Hannah; Svoboda, Daniel; Witt, Kristine L; Merrick, B Alex; Teng, Christina T; Tice, Raymond R

2015-10-01

Multiple mechanisms exist for endocrine disruption; one nonreceptor-mediated mechanism is via effects on aromatase, an enzyme critical for maintaining the normal in vivo balance of androgens and estrogens. We adapted the AroER tri-screen 96-well assay to 1536-well format to identify potential aromatase inhibitors (AIs) in the U.S. Tox21 10K compound library. In this assay, screening with compound alone identifies estrogen receptor alpha (ERα) agonists, screening in the presence of testosterone (T) identifies AIs and/or ERα antagonists, and screening in the presence of 17β-estradiol (E2) identifies ERα antagonists. Screening the Tox-21 library in the presence of T resulted in finding 302 potential AIs. These compounds, along with 31 known AI actives and inactives, were rescreened using all 3 assay formats. Of the 333 compounds tested, 113 (34%; 63 actives, 50 marginal actives) were considered to be potential AIs independent of cytotoxicity and ER antagonism activity. Structure-activity analysis suggested the presence of both conventional (eg, 1, 2, 4, - triazole class) and novel AI structures. Due to their novel structures, 14 of the 63 potential AI actives, including both drugs and fungicides, were selected for confirmation in the biochemical tritiated water-release aromatase assay. Ten compounds were active in the assay; the remaining 4 were only active in high-throughput screen assay, but with low efficacy. To further characterize these 10 novel AIs, we investigated their binding characteristics. The AroER tri-screen, in high-throughput format, accurately and efficiently identified chemicals in a large and diverse chemical library that selectively interact with aromatase. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cell-Based High-Throughput Screening for Aromatase Inhibitors in the Tox21 10K Library

PubMed Central

Chen, Shiuan; Hsieh, Jui-Hua; Huang, Ruili; Sakamuru, Srilatha; Hsin, Li-Yu; Xia, Menghang; Shockley, Keith R.; Auerbach, Scott; Kanaya, Noriko; Lu, Hannah; Svoboda, Daniel; Witt, Kristine L.; Merrick, B. Alex; Teng, Christina T.; Tice, Raymond R.

2015-01-01

Multiple mechanisms exist for endocrine disruption; one nonreceptor-mediated mechanism is via effects on aromatase, an enzyme critical for maintaining the normal in vivo balance of androgens and estrogens. We adapted the AroER tri-screen 96-well assay to 1536-well format to identify potential aromatase inhibitors (AIs) in the U.S. Tox21 10K compound library. In this assay, screening with compound alone identifies estrogen receptor alpha (ERα) agonists, screening in the presence of testosterone (T) identifies AIs and/or ERα antagonists, and screening in the presence of 17β-estradiol (E2) identifies ERα antagonists. Screening the Tox-21 library in the presence of T resulted in finding 302 potential AIs. These compounds, along with 31 known AI actives and inactives, were rescreened using all 3 assay formats. Of the 333 compounds tested, 113 (34%; 63 actives, 50 marginal actives) were considered to be potential AIs independent of cytotoxicity and ER antagonism activity. Structure-activity analysis suggested the presence of both conventional (eg, 1, 2, 4, - triazole class) and novel AI structures. Due to their novel structures, 14 of the 63 potential AI actives, including both drugs and fungicides, were selected for confirmation in the biochemical tritiated water-release aromatase assay. Ten compounds were active in the assay; the remaining 4 were only active in high-throughput screen assay, but with low efficacy. To further characterize these 10 novel AIs, we investigated their binding characteristics. The AroER tri-screen, in high-throughput format, accurately and efficiently identified chemicals in a large and diverse chemical library that selectively interact with aromatase. PMID:26141389

A Multiplexed Assay That Monitors Effects of Multiple Compound Treatment Times Reveals Candidate Immune-Enhancing Compounds.

PubMed

Zhao, Ziyan; Henowitz, Liza; Zweifach, Adam

2018-05-01

We previously developed a flow cytometry assay that monitored lytic granule exocytosis in cytotoxic T lymphocytes stimulated by contacting beads coated with activating anti-CD3 antibodies. That assay was multiplexed in that responses of cells that did or did not receive the activating stimulus were distinguished via changes in light scatter accompanying binding of cells to beads, allowing us to discriminate compounds that activate responses on their own from compounds that enhance responses in cells that received the activating stimulus, all within a single sample. Here we add a second dimension of multiplexing by developing means to assess in a single sample the effects of treating cells with test compounds for different times. Bar-coding cells before adding them to test wells lets us determine compound treatment time while also monitoring activation status and response amplitude at the point of interrogation. This multiplexed assay is suitable for screening 96-well plates. We used it to screen compounds from the National Cancer Institute, identifying several compounds that enhance anti-LAMP1 responses. Multiple-treatment-time (MTT) screening enabled by bar-coding and read via high-throughput flow cytometry may be a generally useful method for facilitating the discovery of compounds of interest.

Dark and Photoinduced Cytotoxic Activity of the New Chlorophyll-a Derivatives with Oligoethylene Glycol Substituents on the Periphery of Their Macrocycles.

PubMed

Pylina, Yana I; Shadrin, Dmitry M; Shevchenko, Oksana G; Startseva, Olga M; Velegzhaninov, Igor O; Belykh, Dmitry V; Velegzhaninov, Ilya O

2017-01-05

In the present work, we investigated the dark and photoinduced cytotoxic activity of the new chlorophyll-a derivatives which contain the substituents of oligoethylene glycol on the periphery of their macrocycles. These compounds were tested using human cell lines to estimate their potential as photosensitizers for photodynamic therapy of cancer. It was shown that all the tested compounds have expressed photoinduced cytotoxic activity in vitro. Detailed study of the biological activity of one of the most perspective compound in this series-pyropheophorbide-a 17-diethylene glycol ester (Compound 21 ) was performed. This new compound is characterized by lower dark cytotoxicity and higher photoinduced cytotoxicity than previously described in a similar compound (DH-I-180-3) and clinically used Photolon TM . Using fluorescent microscopy, it was shown that Compound 21 quickly penetrates the cells. Analysis of caspase-3 activity indicated an apoptosis induction 40 min after exposure to red light (λ = 660 nm). The induction of DNA damages and apoptosis was shown using Comet assay. The results of expression analysis of the stress-response genes indicate an activation of the genes which control the cell cycle and detoxification of the free radicals after an exposure of HeLa cells to Compound 21 and to red light. High photodynamic activity of this compound and the ability to oxidize biomolecules was demonstrated on nuclear-free mice erythrocytes. In addition, it was shown that Compound 21 is effectively activated with low energy 700 nm light, which can penetrate deep into the tissue. Thus, Compound 21 is a prospective substance for development of the new drugs for photodynamic therapy of cancer.

Anticancer activity of seaweeds.

PubMed

Gutiérrez-Rodríguez, Anllely G; Juárez-Portilla, Claudia; Olivares-Bañuelos, Tatiana; Zepeda, Rossana C

2018-02-01

Cancer is a major health problem worldwide and still lacks fully effective treatments. Therefore, alternative therapies, using natural products, have been proposed. Marine algae are an important component of the marine environment, with high biodiversity, and contain a huge number of functional compounds, including terpenes, polyphenols, phlorotannins, and polysaccharides, among others. These compounds have complex structures that have shown several biological activities, including anticancer activity, using in vitro and in vivo models. Moreover, seaweed-derived compounds target important molecules that regulate cancer processes. Here, we review our current understanding of the anticancer activity of seaweeds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Treatment of semivolatile compounds in high strength wastes using an anaerobic expanded-bed GAC reactor

EPA Science Inventory

The potential of the anaerobic, expanded bed granular activated carbon (GAC) reactor in treating a high strength waste containing RCRA semivolatile organic compounds (VOCs) was studied. Six semivolatiles, orthochlorophenol, nitrobenzene, naphthalene, para-nitrophenol, lindane, a...

Efficient Synthesis and Bioactivity of Novel Triazole Derivatives.

PubMed

Hu, Boyang; Zhao, Hanqing; Chen, Zili; Xu, Chen; Zhao, Jianzhuang; Zhao, Wenting

2018-03-21

Triazole pesticides are organic nitrogen-containing heterocyclic compounds, which contain 1,2,3-triazole ring. In order to develop potential glucosamine-6-phosphate synthase (GlmS) inhibitor fungicides, forty compounds of triazole derivatives were synthesized in an efficient way, thirty nine of them were new compounds. The structures of all the compounds were confirmed by high resolution mass spectrometer (HRMS), ¹H-NMR and 13 C-NMR. The fungicidal activities results based on means of mycelium growth rate method indicated that some of the compounds exhibited good fungicidal activities against P. CapasiciLeonian , Sclerotinia sclerotiorum (Lib.) de Bary, Pyricularia oryzae Cav. and Fusarium oxysporum Schl. F.sp. vasinfectum (Atk.) Snyd. & Hans. at the concentration of 50 µg/mL, especially the inhibitory rates of compounds 1-d and 1-f were over 80%. At the same time, the preliminary studies based on the Elson-Morgan method indicated that the compounds exhibited some inhibitory activity toward glucosamine-6-phosphate synthase (GlmS). These compounds will be further studied as potential antifungal lead compounds. The structure-activity relationships (SAR) were discussed in terms of the effects of the substituents on both the benzene and the sugar ring.

Synthesis, analgesic activity, and binding properties of some epibatidine analogs with a tropine skeleton.

PubMed

Rádl, S; Hafner, W; Budesínsky, M; Hejnová, L; Krejcí, I

2000-06-01

A series of epibatidine analogs and their positional isomers bearing an 8-azabicyclo[3.2.1]octane moiety is described. Also some of their simplified analogs bearing a 3-piperidine moiety are reported. Their receptor binding profiles (5-HT1A, 5-HT1B, M1, M2, neuronal nicotinic receptor) and analgesic activity (hot plate, acetic acid induced writhing) have been studied. Some of the compounds, especially those containing an 8-azabicyclo[3.2.1]oct-2-ene moiety possess high afinity for the nicotinic cholinergic receptor. The most analgesically active compounds are also highly toxic. Optimized structures (PM3-MOPAC, Alchemy 2000, Tripos Inc.) of compounds 1-9 were compared with that of epibatidine.

Selective CB2 receptor agonists. Part 2: Structure-activity relationship studies and optimization of proline-based compounds.

PubMed

Riether, Doris; Zindell, Renee; Wu, Lifen; Betageri, Raj; Jenkins, James E; Khor, Someina; Berry, Angela K; Hickey, Eugene R; Ermann, Monika; Albrecht, Claudia; Ceci, Angelo; Gemkow, Mark J; Nagaraja, Nelamangala V; Romig, Helmut; Sauer, Achim; Thomson, David S

2015-02-01

Through a ligand-based pharmacophore model (S)-proline based compounds were identified as potent cannabinoid receptor 2 (CB2) agonists with high selectivity over the cannabinoid receptor 1 (CB1). Structure-activity relationship investigations for this compound class lead to oxo-proline compounds 21 and 22 which combine an impressive CB1 selectivity profile with good pharmacokinetic properties. In a streptozotocin induced diabetic neuropathy model, 22 demonstrated a dose-dependent reversal of mechanical hyperalgesia. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bayesian screening for active compounds in high-dimensional chemical spaces combining property descriptors and molecular fingerprints.

PubMed

Vogt, Martin; Bajorath, Jürgen

2008-01-01

Bayesian classifiers are increasingly being used to distinguish active from inactive compounds and search large databases for novel active molecules. We introduce an approach to directly combine the contributions of property descriptors and molecular fingerprints in the search for active compounds that is based on a Bayesian framework. Conventionally, property descriptors and fingerprints are used as alternative features for virtual screening methods. Following the approach introduced here, probability distributions of descriptor values and fingerprint bit settings are calculated for active and database molecules and the divergence between the resulting combined distributions is determined as a measure of biological activity. In test calculations on a large number of compound activity classes, this methodology was found to consistently perform better than similarity searching using fingerprints and multiple reference compounds or Bayesian screening calculations using probability distributions calculated only from property descriptors. These findings demonstrate that there is considerable synergy between different types of property descriptors and fingerprints in recognizing diverse structure-activity relationships, at least in the context of Bayesian modeling.

Design of novel potent antihyperlipidemic agents with antioxidant/anti-inflammatory properties: exploiting phenothiazine's strong antioxidant activity.

PubMed

Matralis, Alexios N; Kourounakis, Angeliki P

2014-03-27

Because atherosclerosis is an inflammatory process involving a series of pathological events such as dyslipidemia, oxidative stress, and blood clotting mechanisms, we hereby report the synthesis and evaluation of novel compounds in which antioxidant, anti-inflammatory, and squalene synthase (SQS) inhibitory/hypolipidemic activities are combined in simple molecules through design. The coupling of two different pharmacophores afforded compounds 1-12, whose biological profile was markedly improved compared to those of parent lead structures (i.e., the hypolipidemic 2-hydroxy-2-aryl-(benzo)oxa(or thia)zine and the antioxidant phenothiazine). Most derivatives strongly inhibited in vitro microsomal lipid and LDL peroxidation, exhibiting potent free-radical scavenging activity. They further significantly inhibited SQS activity and showed remarkable antidyslipidemic activity in vivo in animal models of acute and high-fat-induced hyperlipidemia. Finally, several compounds showed anti-inflammatory activity in vitro, inhibiting cycloxygenase (COX-1/2) activity. The multimodal properties of the new compounds and especially their combined antioxidant/SQS/COX inhibitory activity render them interesting lead compounds for further evaluation against atherosclerosis.

Evaluation of antioxidant potential, enzyme inhibition activity and phenolic profile of Lathyrus cicera and Lathyrus digitatus: Potential sources of bioactive compounds for the food industry.

PubMed

Llorent-Martínez, E J; Ortega-Barrales, P; Zengin, G; Mocan, A; Simirgiotis, M J; Ceylan, R; Uysal, S; Aktumsek, A

2017-09-01

The genus Lathyrus has great importance in terms of food and agricultural areas. In this study, the in vitro antioxidant activity (phosphomolybdenum, DPPH, ABTS, FRAP, CUPRAC and metal chelating) and enzyme inhibitory activity evaluation (acetylcholinesterase, butyrylcholinesterase, α-amylase and α-glucosidase) of L. cicera and L. digitatus were investigated, as well as their phytochemical profiles. The screening of the main phytochemical compounds in aerial parts of L. cicera and L. digitatus was carried out by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MS n ), observing that flavonoids represent the highest percentage of identified compounds, with abundance of tri- and tetra-glycosilated flavonoids, including acylated ones, especially in L. cicera. Generally, L. digitatus exhibited stronger antioxidant and enzyme inhibitory activities in correlation with its higher level of phenolics. The high number of phenolic compounds and the results of the antioxidant and enzyme assays suggest that these plants may be further used as sources of bioactive compounds, and for the preparation of new nutraceuticals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improved anticancer and antiparasitic activity of new lawsone Mannich bases.

PubMed

Mahal, Katharina; Ahmad, Aamir; Schmitt, Florian; Lockhauserbäumer, Julia; Starz, Kathrin; Pradhan, Rohan; Padhye, Subhash; Sarkar, Fazlul H; Koko, Waleed S; Schobert, Rainer; Ersfeld, Klaus; Biersack, Bernhard

2017-01-27

Substituted lawsone Mannich bases 2a-e, 3a-e and 4a-e were prepared and tested for their biological activities. The new fatty alkyl substituted compounds 2a-c exhibited strong and selective growth inhibitory activities in the low one-digit micromolar and sub-micromolar range against a panel of human cancer cell lines associated with ROS formation. In addition, compounds 2a-c revealed sub-micromolar anti-trypanosomal activities against parasitic Trypanosoma brucei brucei cells via deformation of the microtubule cytoskeleton. The N-hexadecyl compound 2c was also highly active against locally isolated Entamoeba histolytica parasite samples exceeding the activity of metronidazole. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Isolation, Purification, and Characterization of Five Active Diketopiperazine Derivatives from Endophytic Streptomyces SUK 25 with Antimicrobial and Cytotoxic Activities.

PubMed

Alshaibani, Muhanna; Zin, Noraziah; Jalil, Juriyati; Sidik, Nik; Ahmad, Siti Junaidah; Kamal, Nurkhalida; Edrada-Ebel, Ruangelie

2017-07-28

In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as cyclo -( L -Val- L -Pro), cyclo -( L -Leu- L -Pro), cyclo -( L -Phe- L -Pro), cyclo -( L -Val- L -Phe), and N -(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus , with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.

Phytochemical Compounds and Antioxidant Capacity of Tucum-Do-Cerrado (Bactris setosa Mart), Brazil's Native Fruit.

PubMed

Rosa, Fernanda R; Arruda, Andréa F; Siqueira, Egle M A; Arruda, Sandra F

2016-02-23

This study identified major phenolic compounds of the tucum-do-cerrado (Bactris setosa) peel, as well as antioxidant activity and total phytochemical compound concentration of different extracts of the peel and pulp of this fruit. Phenolic compounds of the different extracts of tucum-do-cerrado peel were identified and quantified using a high-performance liquid chromatography system coupled to a diode array detector (DAD). Total phytochemical compound content was determined by spectrophotometric assays and the antioxidant activity by ferric reducing antioxidant power and β-carotene/linoleic assays. Total phenolic, flavanols, total anthocyanins and yellow flavonoids concentration of tucum-do-cerrado were 122-, 14-, 264- and 61-fold higher in the peel than in the pulp, respectively. The aqueous, methanolic and ethanolic extracts of the tucum-do-cerrado peel exhibited higher antioxidant activity compared to its pulp. Flavanols, anthocyanins, flavones, phenolic acids and stilbenes were the main phenolic classes identified in the tucum-do-cerrado peel extracts. Results suggest that the antioxidant capacity and the phytochemical compound content of the tucum-do-cerrado are mainly associated with the peel. Although flavonoids are the main compounds identified in tucum-do-cerrado peel, other phenolics identified in minor amounts, such as phenolic acids and stilbenes, may be responsible for the high antioxidant capacity of the fruit.

Phytochemical Compounds and Antioxidant Capacity of Tucum-Do-Cerrado (Bactris setosa Mart), Brazil’s Native Fruit

PubMed Central

Rosa, Fernanda R.; Arruda, Andréa F.; Siqueira, Egle M. A.; Arruda, Sandra F.

2016-01-01

This study identified major phenolic compounds of the tucum-do-cerrado (Bactris setosa) peel, as well as antioxidant activity and total phytochemical compound concentration of different extracts of the peel and pulp of this fruit. Phenolic compounds of the different extracts of tucum-do-cerrado peel were identified and quantified using a high-performance liquid chromatography system coupled to a diode array detector (DAD). Total phytochemical compound content was determined by spectrophotometric assays and the antioxidant activity by ferric reducing antioxidant power and β-carotene/linoleic assays. Total phenolic, flavanols, total anthocyanins and yellow flavonoids concentration of tucum-do-cerrado were 122-, 14-, 264- and 61-fold higher in the peel than in the pulp, respectively. The aqueous, methanolic and ethanolic extracts of the tucum-do-cerrado peel exhibited higher antioxidant activity compared to its pulp. Flavanols, anthocyanins, flavones, phenolic acids and stilbenes were the main phenolic classes identified in the tucum-do-cerrado peel extracts. Results suggest that the antioxidant capacity and the phytochemical compound content of the tucum-do-cerrado are mainly associated with the peel. Although flavonoids are the main compounds identified in tucum-do-cerrado peel, other phenolics identified in minor amounts, such as phenolic acids and stilbenes, may be responsible for the high antioxidant capacity of the fruit. PMID:26907338

UDP-N-acetylmuramic acid l-alanine ligase (MurC) inhibition in a tolC mutant Escherichia coli strain leads to cell death.

PubMed

Humnabadkar, Vaishali; Prabhakar, K R; Narayan, Ashwini; Sharma, Sreevalli; Guptha, Supreeth; Manjrekar, Praveena; Chinnapattu, Murugan; Ramachandran, Vasanthi; Hameed, Shahul P; Ravishankar, Sudha; Chatterji, Monalisa

2014-10-01

The Mur ligases play an essential role in the biosynthesis of bacterial peptidoglycan and hence are attractive antibacterial targets. A screen of the AstraZeneca compound library led to the identification of compound A, a pyrazolopyrimidine, as a potent inhibitor of Escherichia coli and Pseudomonas aeruginosa MurC. However, cellular activity against E. coli or P. aeruginosa was not observed. Compound A was active against efflux pump mutants of both strains. Experiments using an E. coli tolC mutant revealed accumulation of the MurC substrate and a decrease in the level of product upon treatment with compound A ,: indicating inhibition of MurC enzyme in these cells. Such a modulation was not observed in the E. coli wild-type cells. Further, overexpression of MurC in the E. coli tolC mutant led to an increase in the compound A MIC by ≥16-fold, establishing a correlation between MurC inhibition and cellular activity. In addition, estimation of the intracellular compound A level showed an accumulation of the compound over time in the tolC mutant strain. A significant compound A level was not detected in the wild-type E. coli strain even upon treatment with high concentrations of the compound. Therefore, the lack of MIC and absence of MurC inhibition in wild-type E. coli were possibly due to suboptimal compound concentration as a consequence of a high efflux level and/or poor permeativity of compound A. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

UDP-N-Acetylmuramic Acid l-Alanine Ligase (MurC) Inhibition in a tolC Mutant Escherichia coli Strain Leads to Cell Death

PubMed Central

Humnabadkar, Vaishali; Prabhakar, K. R.; Narayan, Ashwini; Sharma, Sreevalli; Guptha, Supreeth; Manjrekar, Praveena; Chinnapattu, Murugan; Ramachandran, Vasanthi; Hameed, Shahul P.; Ravishankar, Sudha

2014-01-01

The Mur ligases play an essential role in the biosynthesis of bacterial peptidoglycan and hence are attractive antibacterial targets. A screen of the AstraZeneca compound library led to the identification of compound A, a pyrazolopyrimidine, as a potent inhibitor of Escherichia coli and Pseudomonas aeruginosa MurC. However, cellular activity against E. coli or P. aeruginosa was not observed. Compound A was active against efflux pump mutants of both strains. Experiments using an E. coli tolC mutant revealed accumulation of the MurC substrate and a decrease in the level of product upon treatment with compound A, indicating inhibition of MurC enzyme in these cells. Such a modulation was not observed in the E. coli wild-type cells. Further, overexpression of MurC in the E. coli tolC mutant led to an increase in the compound A MIC by ≥16-fold, establishing a correlation between MurC inhibition and cellular activity. In addition, estimation of the intracellular compound A level showed an accumulation of the compound over time in the tolC mutant strain. A significant compound A level was not detected in the wild-type E. coli strain even upon treatment with high concentrations of the compound. Therefore, the lack of MIC and absence of MurC inhibition in wild-type E. coli were possibly due to suboptimal compound concentration as a consequence of a high efflux level and/or poor permeativity of compound A. PMID:25114134

Synthesis, structure-activity relationship and molecular docking of cyclohexenone based analogous as potent non-nucleoside reverse-transcriptase inhibitors

NASA Astrophysics Data System (ADS)

Nazar, Muhammad Faizan; Abdullah, Muhammad Imran; Badshah, Amir; Mahmood, Asif; Rana, Usman Ali; Khan, Salah Ud-Din

2015-04-01

The chalcones core in compounds is advantageously chosen effective synthons, which offer exciting perspectives in biological and pharmacological research. The present study reports the successful development of eight new cyclohexenone based anti-reverse transcriptase analogous using rational drug design synthesis principles. These new cyclohexenone derivatives (CDs) were synthesized by following a convenient route of Robinson annulation, and the molecular structure of these CDs were later confirmed by various analytical techniques such as 1H NMR, 13C NMR, FT-IR, UV-Vis spectroscopy and mass spectrometry. All the synthesized compounds were screened theoretically and experimentally against reverse transcriptase (RT) and found potentially active reverse transcriptase (RT) inhibitors. Of the compounds studied, the compound 2FC4 showed high interaction with RT at non-nucleoside binding site, contributing high free binding energy (ΔG -8.01 Kcal) and IC50 (0.207 μg/ml), respectively. Further results revealed that the compounds bearing more halogen groups, with additional hydrophobic character, offered superior anti-reverse transcriptase activity as compared to rest of compounds. It is anticipate that the present study would be very useful for the selection of potential reverse transcriptase inhibitors featuring inclusive pharmacological profiles.

Identification of Three Classes of Heteroaromatic Compounds with Activity against Intracellular Trypanosoma cruzi by Chemical Library Screening

PubMed Central

Bettiol, Esther; Samanovic, Marie; Murkin, Andrew S.; Raper, Jayne; Buckner, Frederick; Rodriguez, Ana

2009-01-01

The development of new drugs against Chagas disease is a priority since the currently available medicines have toxic effects, partial efficacy and are targeted against the acute phase of disease. At present, there is no drug to treat the chronic stage. In this study, we have optimized a whole cell-based assay for high throughput screening of compounds that inhibit infection of mammalian cells by Trypanosoma cruzi trypomastigotes. A 2000-compound chemical library was screened using a recombinant T. cruzi (Tulahuen strain) expressing β-galactosidase. Three hits were selected for their high activity against T. cruzi and low toxicity to host cells in vitro: PCH1, NT1 and CX1 (IC50: 54, 190 and 23 nM, respectively). Each of these three compounds presents a different mechanism of action on intracellular proliferation of T. cruzi amastigotes. CX1 shows strong trypanocidal activity, an essential characteristic for the development of drugs against the chronic stage of Chagas disease where parasites are found intracellular in a quiescent stage. NT1 has a trypanostatic effect, while PCH1 affects parasite division. The three compounds also show high activity against intracellular T. cruzi from the Y strain and against the related kinetoplastid species Leishmania major and L. amazonensis. Characterization of the anti–T. cruzi activity of molecules chemically related to the three library hits allowed the selection of two compounds with IC50 values of 2 nM (PCH6 and CX2). These values are approximately 100 times lower than those of the medicines used in patients against T. cruzi. These results provide new candidate molecules for the development of treatments against Chagas disease and leishmaniasis. PMID:19238193

Identification of three classes of heteroaromatic compounds with activity against intracellular Trypanosoma cruzi by chemical library screening.

PubMed

Bettiol, Esther; Samanovic, Marie; Murkin, Andrew S; Raper, Jayne; Buckner, Frederick; Rodriguez, Ana

2009-01-01

The development of new drugs against Chagas disease is a priority since the currently available medicines have toxic effects, partial efficacy and are targeted against the acute phase of disease. At present, there is no drug to treat the chronic stage. In this study, we have optimized a whole cell-based assay for high throughput screening of compounds that inhibit infection of mammalian cells by Trypanosoma cruzi trypomastigotes. A 2000-compound chemical library was screened using a recombinant T. cruzi (Tulahuen strain) expressing beta-galactosidase. Three hits were selected for their high activity against T. cruzi and low toxicity to host cells in vitro: PCH1, NT1 and CX1 (IC(50): 54, 190 and 23 nM, respectively). Each of these three compounds presents a different mechanism of action on intracellular proliferation of T. cruzi amastigotes. CX1 shows strong trypanocidal activity, an essential characteristic for the development of drugs against the chronic stage of Chagas disease where parasites are found intracellular in a quiescent stage. NT1 has a trypanostatic effect, while PCH1 affects parasite division. The three compounds also show high activity against intracellular T. cruzi from the Y strain and against the related kinetoplastid species Leishmania major and L. amazonensis. Characterization of the anti-T. cruzi activity of molecules chemically related to the three library hits allowed the selection of two compounds with IC(50) values of 2 nM (PCH6 and CX2). These values are approximately 100 times lower than those of the medicines used in patients against T. cruzi. These results provide new candidate molecules for the development of treatments against Chagas disease and leishmaniasis.

A new antioxidant beverage produced with green tea and apple.

PubMed

Rubio-Perez, Jose M; Vidal-Guevara, Maria L; Zafrilla, Pilar; Morillas-Ruiz, Juana M

2014-08-01

Green tea and apple are natural products with health benefits. These healthy properties are linked closely to the antioxidant compounds, mainly phenolic compounds. These antioxidant compounds have a potential for preventing and treating cancer, cardiovascular, inflammatory and neurodegenerative diseases in humans. The aim of the present work was to design a new beverage with high antioxidant power combining extracts of green tea and apple, studying the antioxidant composition and activity, organoleptic properties (colour) and stability status during storage at different temperatures. The majority compounds identified in the beverage were flavan-3-ols, being the (-)-epigallocatechin-3-gallate which had the highest concentration. After storage, floridzine was the compound with lower decrease of concentration. The new designed beverage had a good colour, and high antioxidant activity and stability at room temperature, so that the beverage needs no refrigeration, showing potential for the development of new healthy functional beverages.

High content image-based screening of a protease inhibitor library reveals compounds broadly active against Rift Valley fever virus and other highly pathogenic RNA viruses.

PubMed

Mudhasani, Rajini; Kota, Krishna P; Retterer, Cary; Tran, Julie P; Whitehouse, Chris A; Bavari, Sina

2014-08-01

High content image-based screening was developed as an approach to test a protease inhibitor small molecule library for antiviral activity against Rift Valley fever virus (RVFV) and to determine their mechanism of action. RVFV is the causative agent of severe disease of humans and animals throughout Africa and the Arabian Peninsula. Of the 849 compounds screened, 34 compounds exhibited ≥ 50% inhibition against RVFV. All of the hit compounds could be classified into 4 distinct groups based on their unique chemical backbone. Some of the compounds also showed broad antiviral activity against several highly pathogenic RNA viruses including Ebola, Marburg, Venezuela equine encephalitis, and Lassa viruses. Four hit compounds (C795-0925, D011-2120, F694-1532 and G202-0362), which were most active against RVFV and showed broad-spectrum antiviral activity, were selected for further evaluation for their cytotoxicity, dose response profile, and mode of action using classical virological methods and high-content imaging analysis. Time-of-addition assays in RVFV infections suggested that D011-2120 and G202-0362 targeted virus egress, while C795-0925 and F694-1532 inhibited virus replication. We showed that D011-2120 exhibited its antiviral effects by blocking microtubule polymerization, thereby disrupting the Golgi complex and inhibiting viral trafficking to the plasma membrane during virus egress. While G202-0362 also affected virus egress, it appears to do so by a different mechanism, namely by blocking virus budding from the trans Golgi. F694-1532 inhibited viral replication, but also appeared to inhibit overall cellular gene expression. However, G202-0362 and C795-0925 did not alter any of the morphological features that we examined and thus may prove to be good candidates for antiviral drug development. Overall this work demonstrates that high-content image analysis can be used to screen chemical libraries for new antivirals and to determine their mechanism of action and any possible deleterious effects on host cellular biology.

High Content Image-Based Screening of a Protease Inhibitor Library Reveals Compounds Broadly Active against Rift Valley Fever Virus and Other Highly Pathogenic RNA Viruses

PubMed Central

Mudhasani, Rajini; Kota, Krishna P.; Retterer, Cary; Tran, Julie P.; Whitehouse, Chris A.; Bavari, Sina

2014-01-01

High content image-based screening was developed as an approach to test a protease inhibitor small molecule library for antiviral activity against Rift Valley fever virus (RVFV) and to determine their mechanism of action. RVFV is the causative agent of severe disease of humans and animals throughout Africa and the Arabian Peninsula. Of the 849 compounds screened, 34 compounds exhibited ≥50% inhibition against RVFV. All of the hit compounds could be classified into 4 distinct groups based on their unique chemical backbone. Some of the compounds also showed broad antiviral activity against several highly pathogenic RNA viruses including Ebola, Marburg, Venezuela equine encephalitis, and Lassa viruses. Four hit compounds (C795-0925, D011-2120, F694-1532 and G202-0362), which were most active against RVFV and showed broad-spectrum antiviral activity, were selected for further evaluation for their cytotoxicity, dose response profile, and mode of action using classical virological methods and high-content imaging analysis. Time-of-addition assays in RVFV infections suggested that D011-2120 and G202-0362 targeted virus egress, while C795-0925 and F694-1532 inhibited virus replication. We showed that D011-2120 exhibited its antiviral effects by blocking microtubule polymerization, thereby disrupting the Golgi complex and inhibiting viral trafficking to the plasma membrane during virus egress. While G202-0362 also affected virus egress, it appears to do so by a different mechanism, namely by blocking virus budding from the trans Golgi. F694-1532 inhibited viral replication, but also appeared to inhibit overall cellular gene expression. However, G202-0362 and C795-0925 did not alter any of the morphological features that we examined and thus may prove to be good candidates for antiviral drug development. Overall this work demonstrates that high-content image analysis can be used to screen chemical libraries for new antivirals and to determine their mechanism of action and any possible deleterious effects on host cellular biology. PMID:25144302

Synthesis of isatin thiosemicarbazones derivatives: in vitro anti-cancer, DNA binding and cleavage activities.

PubMed

Ali, Amna Qasem; Teoh, Siang Guan; Salhin, Abdussalam; Eltayeb, Naser Eltaher; Khadeer Ahamed, Mohamed B; Abdul Majid, A M S

2014-05-05

New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (k(b)=5.03-33.00×10(5) M(-1)) for L1-L3 and L5 and (6.14-9.47×10(4) M(-1)) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency. Copyright © 2014 Elsevier B.V. All rights reserved.

4-Aminoquinoline-pyrimidine hybrids: synthesis, antimalarial activity, heme binding and docking studies.

PubMed

Kumar, Deepak; Khan, Shabana I; Tekwani, Babu L; Ponnan, Prija; Rawat, Diwan S

2015-01-07

A series of novel 4-aminoquinoline-pyrimidine hybrids has been synthesized and evaluated for their antimalarial activity. Several compounds showed promising in vitro antimalarial activity against both CQ-sensitive and CQ-resistant strains with high selectivity index. All the compounds were found to be non-toxic to the mammalian cell lines. Selected compound 7g exhibited significant suppression of parasitemia in the in vivo assay. The heme binding studies were conducted to determine the mode of action of these hybrid molecules. These compounds form a stable 1:1 complex with hematin suggesting that heme may be one of the possible targets of these hybrids. The interaction of these conjugate hybrids was also investigated by the molecular docking studies in the binding site of PfDHFR. The pharmacokinetic property analysis of best active compounds was also studied using ADMET prediction. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Discovery of potent and selective rhodanine type IKKβ inhibitors by hit-to-lead strategy.

PubMed

Song, Hyeseung; Lee, Yun Suk; Roh, Eun Joo; Seo, Jae Hong; Oh, Kwang-Seok; Lee, Byung Ho; Han, Hogyu; Shin, Kye Jung

2012-09-01

Regulation of NF-κB activation through the inhibition of IKKβ has been identified as a promising target for the treatment of inflammatory and autoimmune disease such as rheumatoid arthritis. In order to develop novel IKKβ inhibitors, we performed high throughput screening toward around 8000 library compounds, and identified a hit compound containing rhodanine moiety. We modified the structure of hit compound to obtain potent and selective IKKβ inhibitors. Throughout hit-to-lead studies, we have discovered optimized compounds which possess blocking effect toward NF-κB activation and TNFα production in cell as well as inhibition activity against IKKβ. Among them, compound 3q showed the potent inhibitory activity against IKKβ, and excellent selectivity over other kinases such as p38α, p38β, JNK1, JNK2, and JNK3 as well as IKKα. Copyright © 2012 Elsevier Ltd. All rights reserved.

Identification of Novel Small Molecule Activators of Nuclear Factor-κB With Neuroprotective Action Via High-Throughput Screening

PubMed Central

Manuvakhova, Marina S.; Johnson, Guyla G.; White, Misti C.; Ananthan, Subramaniam; Sosa, Melinda; Maddox, Clinton; McKellip, Sara; Rasmussen, Lynn; Wennerberg, Krister; Hobrath, Judith V.; White, E. Lucile; Maddry, Joseph A.; Grimaldi, Maurizio

2012-01-01

Neuronal noncytokine-dependent p50/p65 nuclear factor-κB (the primary NF-κB complex in the brain) activation has been shown to exert neuroprotective actions. Thus neuronal activation of NF-κB could represent a viable neuroprotective target. We have developed a cell-based assay able to detect NF-κB expression enhancement, and through its use we have identified small molecules able to up-regulate NF-κB expression and hence trigger its activation in neurons. We have successfully screened approximately 300,000 compounds and identified 1,647 active compounds. Cluster analysis of the structures within the hit population yielded 14 enriched chemical scaffolds. One high-potency and chemically attractive representative of each of these 14 scaffolds and four singleton structures were selected for follow-up. The experiments described here highlighted that seven compounds caused noncanonical long-lasting NF-κB activation in primary astrocytes. Molecular NF-κB docking experiments indicate that compounds could be modulating NF-κB-induced NF-κB expression via enhancement of NF-κB binding to its own promoter. Prototype compounds increased p65 expression in neurons and caused its nuclear translocation without affecting the inhibitor of NF-κB (I-κB). One of the prototypical compounds caused a large reduction of glutamate-induced neuronal death. In conclusion, we have provided evidence that we can use small molecules to activate p65 NF-κB expression in neurons in a cytokine receptor-independent manner, which results in both long-lasting p65 NF-κB translocation/activation and decreased glutamate neurotoxicity. PMID:21046675

Compound C induces protective autophagy in human cholangiocarcinoma cells via Akt/mTOR-independent pathway.

PubMed

Zhao, Xiaofang; Luo, Guosong; Cheng, Ying; Yu, Wenjing; Chen, Run; Xiao, Bin; Xiang, Yuancai; Feng, Chunhong; Fu, Wenguang; Duan, Chunyan; Yao, Fuli; Xia, Xianming; Tao, Qinghua; Wei, Mei; Dai, Rongyang

2018-07-01

Compound C, a well-known inhibitor of AMP-activated protein kinase (AMPK), has been reported to exert antitumor activities in some types of cells. Whether compound C can exert antitumor effects in human cholangiocarcinoma (CCA) remains unknown. Here, we demonstrated that compound C is a potent inducer of cell death and autophagy in human CCA cells. Autophagy inhibitors increased the cytotoxicity of compound C towards human CCA cells, as confirmed by increased LDH release, and PARP cleavage. It is notable that compound C treatment increased phosphorylated Akt, sustained high levels of phosphorylated p70S6K, and decreased mTOR regulated p-ULK1 (ser757). Based on the data that blocking PI3K/Akt or mTOR had no apparent influence on autophagic response, we suggest that compound C induces autophagy independent of Akt/mTOR signaling in human CCA cells. Further study demonstrated that compound C inhibited the phosphorylation of JNK and its target c-Jun. Blocking JNK by SP600125 or siRNA suppressed autophagy induction upon compound C treatment. Moreover, compound C induced p38 MAPK activation, and its inhibition promoted autophagy induction via JNK activation. In addition, compound C induced p53 expression, and its inhibition attenuated compound C-induced autophagic response. Thus, compound C triggers autophagy, at least in part, via the JNK and p53 pathways in human CCA cells. In conclusion, suppresses autophagy could increase compound C sensitivity in human CCA. © 2018 Wiley Periodicals, Inc.

Synthesis, pharmacological activities and molecular docking studies of pyrazolyltriazoles as anti-bacterial and anti-inflammatory agents.

PubMed

Dayakar, Cherupally; Kumar, Buddana Sudheer; Sneha, Galande; Sagarika, Gudem; Meghana, Koneru; Ramakrishna, Sistla; Prakasham, Reddy Shetty; China Raju, Bhimapaka

2017-10-15

A series of novel pyrazolyl alcohols (5a-h), pyrazolyl azides (6a-h), and pyrazolyltriazoles (8a-h, 10a-p and 12a-l) were prepared and evaluated for their bioactivity (anti-bacterial and anti-inflammatory) profile. The compound 5c displayed the potent anti-bacterial activity against Micrococcus luteus (MIC 3.9 and MBC 7.81µg/mL). In vitro anti-inflammatory activity data denoted that compound 8b is effective among the tested compounds against IL-6 (IC 50 6.23μM). Docking analysis of compounds 5f, 8a-b, 8e-f and 8h displayed high binding energies for the compounds 8a-b and 8h towards TNF-α dimer (2AZ5 protein) and IL-6 (1ALU protein). In vivo anti-inflammatory activity of compounds 8b and 8h with respect to LPS induced mice model indicated that compound 8h showed significant reduction in TNF-α. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation and Identification of Algicidal Compound from Streptomyces and Algicidal Mechanism to Microcystis aeruginosa

PubMed Central

Luo, Jianfei; Wang, Yuan; Tang, Shuishui; Liang, Jianwen; Lin, Weitie; Luo, Lixin

2013-01-01

The biological control of cyanobacterial harmful algal blooms (cyanoHABs) is important to promote human health, environmental protection, and economic growth. Active algicidal compounds and algicidal mechanisms should be identified and investigated to control cyanoHABs. In this study, the algicidal actinobacterium Streptomyces sp. L74 was isolated from the soil of a nearby pond which located in the center lake of Guanghzou Higher Education Mega Center. Results showed that the algicidal activities of cyanoHABs are mainly achieved via an indirect attack by producing algicidal compounds. All active algicidal compounds are hydrophilic substances that are heat and pH stable. In the present study, an active compound (B3) was isolated and purified by high-performance liquid chromatography and identified as a type of triterpenoid saponin (2-hydroxy-12-oleanene-3, 28-O-D-glucopyranosyl) with a molecular formula of C42H70O13 as determined by infrared spectrometry, electrospray ionization mass spectrometry, and nuclear magnetic resonance. Active algicidal compounds from Streptomyces sp. L74 were shown to disrupt the antioxidant systems of Microcystis aeruginosa cells. PMID:24098501

Isolation and identification of algicidal compound from Streptomyces and algicidal mechanism to Microcystis aeruginosa.

PubMed

Luo, Jianfei; Wang, Yuan; Tang, Shuishui; Liang, Jianwen; Lin, Weitie; Luo, Lixin

2013-01-01

The biological control of cyanobacterial harmful algal blooms (cyanoHABs) is important to promote human health, environmental protection, and economic growth. Active algicidal compounds and algicidal mechanisms should be identified and investigated to control cyanoHABs. In this study, the algicidal actinobacterium Streptomyces sp. L74 was isolated from the soil of a nearby pond which located in the center lake of Guanghzou Higher Education Mega Center. Results showed that the algicidal activities of cyanoHABs are mainly achieved via an indirect attack by producing algicidal compounds. All active algicidal compounds are hydrophilic substances that are heat and pH stable. In the present study, an active compound (B3) was isolated and purified by high-performance liquid chromatography and identified as a type of triterpenoid saponin (2-hydroxy-12-oleanene-3, 28-O-D-glucopyranosyl) with a molecular formula of C42H70O13 as determined by infrared spectrometry, electrospray ionization mass spectrometry, and nuclear magnetic resonance. Active algicidal compounds from Streptomyces sp. L74 were shown to disrupt the antioxidant systems of Microcystis aeruginosa cells.

A 4-(o-chlorophenyl)-2-aminothiazole: Microwave assisted synthesis, spectral, thermal, XRD and biological studies

NASA Astrophysics Data System (ADS)

Rajmane, S. V.; Ubale, V. P.; Lawand, A. S.; Nalawade, A. M.; Karale, N. N.; More, P. G.

2013-11-01

A 4-(o-chlorophenyl)-2-aminothiazole (CPAT) has been synthesized by reacting o-chloroacetophenone, iodine and thiourea under microwave irradiation as a green chemistry approach. The reactions proceed selectively and within a couple of minutes giving high yields of the products. The compound was characterized by elemental, spectral (UV-visible, IR, NMR and GC-MS), XRD and thermal analyses. The TG curve of the compound was analyzed to calculate various kinetic parameters (n, E, Z, ΔS and ΔG) by using Coats-Redfern (C.R.), MacCallum-Tanner (M.T.) and Horowitz-Metzger (H.M.) method. The compound was tested for the evaluation of antibacterial activity against B. subtilis and E. coli and antifungal activity against A. niger and C. albicans. The compound was evaluated for their in vitro nematicidal activity on plant parasitic nematode Meloidogyne javanica and molluscicidal activity on fresh water helminthiasis vector snail Lymnea auricularia. The compound is biologically active in very low concentration. X-ray diffraction study suggests a triclinic crystal system for the compound.

Bioactive Compound Contents and Antioxidant Activity in Aronia (Aronia melanocarpa) Leaves Collected at Different Growth Stages.

PubMed

Thi, Nhuan Do; Hwang, Eun-Sun

2014-09-01

The bioactive compounds and antioxidant activity of aronia leaves at different stages of maturity were identified and evaluated. Young and old leaves were approximately 2 months of age and 4 months of age, respectively. The young leaves contained more polyphenols and flavonoids than the old leaves. Three phenolic compounds (i.e., chlorogenic acid, p-coumaric acid, and rutin) were detected by HPLC. Antioxidant activity was measured using 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical, and superoxide anion radical scavenging assays. The reducing power of aronia leaf extracts increased in a concentration-dependent manner (0~100 μg/mL). The antioxidant activity of the 80% ethanol extract was greater than that of distilled water extract. The high phenolic compound content indicated that these compounds contribute to antioxidant activity. The overall results indicate that aronia leaves contain bioactive compounds, and that younger aronia leaves may be more favorable for extracting antioxidative ingredients because they contain more polyphenols.

Bioactive Compound Contents and Antioxidant Activity in Aronia (Aronia melanocarpa) Leaves Collected at Different Growth Stages

PubMed Central

Thi, Nhuan Do; Hwang, Eun-Sun

2014-01-01

The bioactive compounds and antioxidant activity of aronia leaves at different stages of maturity were identified and evaluated. Young and old leaves were approximately 2 months of age and 4 months of age, respectively. The young leaves contained more polyphenols and flavonoids than the old leaves. Three phenolic compounds (i.e., chlorogenic acid, p-coumaric acid, and rutin) were detected by HPLC. Antioxidant activity was measured using 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical, and superoxide anion radical scavenging assays. The reducing power of aronia leaf extracts increased in a concentration-dependent manner (0~100 μg/mL). The antioxidant activity of the 80% ethanol extract was greater than that of distilled water extract. The high phenolic compound content indicated that these compounds contribute to antioxidant activity. The overall results indicate that aronia leaves contain bioactive compounds, and that younger aronia leaves may be more favorable for extracting antioxidative ingredients because they contain more polyphenols. PMID:25320718

Concurrent suppression of NF-κB, p38 MAPK and reactive oxygen species formation underlies the effect of a novel compound isolated from Curcuma comosa Roxb. in LPS-activated microglia.

PubMed

Jiamvoraphong, Nittaya; Jantaratnotai, Nattinee; Sanvarinda, Pantip; Tuchinda, Patoomratana; Piyachaturawat, Pawinee; Thampithak, Anusorn; Sanvarinda, Pimtip

2017-07-01

We investigated the molecular mechanisms underlying the effect of (3S)-1-(3,4-dihydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol, also known as compound 092, isolated from Curcuma comosa Roxb on the production of pro-inflammatory mediators and oxidative stress in lipopolysaccharide (LPS)-activated highly aggressive proliferating immortalized (HAPI) microglial cell lines. Nitric oxide (NO) production was determined using the Griess reaction, and reverse transcription polymerase chain reaction was used to measure the expression of inducible nitric oxide synthase (iNOS) mRNA. Western blotting was used to determine the levels of pro-inflammatory mediators and their related upstream proteins. Compound 092 suppressed NO production and iNOS expression in LPS-stimulated HAPI cells. These effects originated from the ability of compound 092 to attenuate the activation of nuclear factor (NF)-κB as determined by the reduction in p-NF-κB and p-IκB kinase (IKK) protein levels. Compound 092 also significantly lowered LPS-activated intracellular reactive oxygen species production and p38 mitogen-activated protein kinase (MAPK) activation. Compound 092 suppresses microglial activation through attenuation of p38 MAPK and NF-κB activation. Compound 092 thus holds the potential to treat neurodegenerative disorders associated with neuroinflammation and oxidative stress. © 2017 Royal Pharmaceutical Society.

Iterative Refinement of a Binding Pocket Model: Active Computational Steering of Lead Optimization

PubMed Central

2012-01-01

Computational approaches for binding affinity prediction are most frequently demonstrated through cross-validation within a series of molecules or through performance shown on a blinded test set. Here, we show how such a system performs in an iterative, temporal lead optimization exercise. A series of gyrase inhibitors with known synthetic order formed the set of molecules that could be selected for “synthesis.” Beginning with a small number of molecules, based only on structures and activities, a model was constructed. Compound selection was done computationally, each time making five selections based on confident predictions of high activity and five selections based on a quantitative measure of three-dimensional structural novelty. Compound selection was followed by model refinement using the new data. Iterative computational candidate selection produced rapid improvements in selected compound activity, and incorporation of explicitly novel compounds uncovered much more diverse active inhibitors than strategies lacking active novelty selection. PMID:23046104

Novel Anthra[1,2-c][1,2,5]Thiadiazole-6,11-Diones as Promising Anticancer Lead Compounds: Biological Evaluation, Characterization & Molecular Targets Determination.

PubMed

Ali, Ahmed Atef Ahmed; Lee, Yu-Ru; Chen, Tsung-Chih; Chen, Chun-Liang; Lee, Chia-Chung; Shiau, Chia-Yang; Chiang, Chiao-Hsi; Huang, Hsu-Shan

2016-01-01

The novel compounds NSC745885 and NSC757963 developed at our laboratory were tested against a panel of 60 cancer cell lines at the National Cancer Institute, USA, and a panel of 39 cancer cell lines at the Japanese Foundation of Cancer Research. Both compounds demonstrated selective unique multi-log differential patterns of activity, with GI50 values in the sub-micro molar range against cancer cells rather than normal cardiac cells. NSC757963 showed high selectivity towards the leukemia subpanel. Activities of both compounds strongly correlated to expression of NFKB1 and CSNK2B genes, implying that they may inhibit the NF-κB pathway. Immunocytochemical microscopy of OVCAR-3 cells showed clear cytosolic accumulation of the NF-κB p65 subunit following treatment. Western blotting showed dose dependent inhibition of the nuclear expression of the NF-κB p65 subunit with subsequent accumulation in the cytosol following treatment. Docking experiments showed binding of both compounds to the NF-κB activator IKKβ subunit preventing its translocation to the nucleus. Collectively, these results confirm the ability of our compounds to inhibit the constitutively active NF-κB pathway of OVCAR-3 cells. Furthermore, COMPARE analysis indicated that the activity of NSC757963 is similar to the antituberculosis agent rifamycin SV, this was confirmed by testing the antimycobacterial activity of NSC757963 against Mycobacterium tuberculosis, results revealed potent activity suitable for use in clinical practice. Molecular properties and Lipinski's parameters predicted acceptable bioavailability properties with no indication of mutagenicity, tumorigenicity, irritability and reproductive effects. Oral absorption experiments using the human Caco-2 model showed high intestinal absorption of NSC745885 by passive transport mechanism with no intestinal efflux or active transport mechanisms. The unique molecular characterization as well as the illustrated anticancer spectra of activity and bioavailability properties warrant further development of our compounds and present a foundation brick in the pre-clinical investigations to implement such compounds in clinical practice.

Biphasic regulation of polymorphonuclear leukocyte spreading by polyphenolic compounds with pyrogallol moieties.

PubMed

Kori, Soichiro; Namiki, Hideo; Suzuki, Kingo

2009-09-01

Green tea polyphenols have been reported to have anti-inflammatory activities, although the molecular mechanisms responsible for this effect remain unclear. In the present study, we examined the effect of green tea extract and a variety of polyphenolic compounds on spreading of peripheral blood polymorphonuclear leukocytes (PMNs) over fibrinogen-coated surfaces. Green tea extract exerted a biphasic effect on PMN spreading; it induced or suppressed spreading at low and high concentrations, respectively. We also found that pyrogallol-bearing compounds have spreading induction activity. Among the compounds tested, tannic acid (TA) had the strongest activity; the concentrations required for induction of maximal spreading were 2 microM for TA, 200 microM for (-)-epigallocatechin gallate, and 2000 microM for the other active compounds. Furthermore, TA was the only compound showing a biphasic effect similar to that of green tea extract; TA at 20 or 200 microM suppressed spreading. The spreading-stimulatory signal was still latent during PMN exposure to TA at concentrations that inhibited spreading, because the pre-exposed PMNs underwent spreading when plated after removal of free TA by centrifugation. The spreading-inhibitory effect of TA at high concentrations overcame the induction of spreading by other stimuli, including phorbol 12-myristate 13-acetate, hydrogen peroxide, denatured fibrinogen surfaces, and naked plastic surfaces. These results suggest that TA as well as green tea extract is bi-functional, having pro-inflammatory and anti-inflammatory effects at low and high concentrations, respectively. Pharmacological use of TA may thus provide new strategies aimed at regulation of PMN spreading for control of inflammation.

Identification of Small Molecule Inhibitors of Clostridium perfringens ε-Toxin Cytotoxicity Using a Cell-Based High-Throughput Screen.

PubMed

Lewis, Michelle; Weaver, Charles David; McClain, Mark S

2010-07-01

The Clostridium perfringens epsilon toxin, a select agent, is responsible for a severe, often fatal enterotoxemia characterized by edema in the heart, lungs, kidney, and brain. The toxin is believed to be an oligomeric pore-forming toxin. Currently, there is no effective therapy for countering the cytotoxic activity of the toxin in exposed individuals. Using a robust cell-based high-throughput screening (HTS) assay, we screened a 151,616-compound library for the ability to inhibit ε-toxin-induced cytotoxicity. Survival of MDCK cells exposed to the toxin was assessed by addition of resazurin to detect metabolic activity in surviving cells. The hit rate for this screen was 0.6%. Following a secondary screen of each hit in triplicate and assays to eliminate false positives, we focused on three structurally-distinct compounds: an N-cycloalkylbenzamide, a furo[2,3-b]quinoline, and a 6H-anthra[1,9-cd]isoxazol. None of the three compounds appeared to inhibit toxin binding to cells or the ability of the toxin to form oligomeric complexes. Additional assays demonstrated that two of the inhibitory compounds inhibited ε-toxin-induced permeabilization of MDCK cells to propidium iodide. Furthermore, the two compounds exhibited inhibitory effects on cells pre-treated with toxin. Structural analogs of one of the inhibitors identified through the high-throughput screen were analyzed and provided initial structure-activity data. These compounds should serve as the basis for further structure-activity refinement that may lead to the development of effective anti-ε-toxin therapeutics.

Identification of Small Molecule Inhibitors of Clostridium perfringens ε-Toxin Cytotoxicity Using a Cell-Based High-Throughput Screen

PubMed Central

Lewis, Michelle; Weaver, Charles David; McClain, Mark S.

2010-01-01

The Clostridium perfringens epsilon toxin, a select agent, is responsible for a severe, often fatal enterotoxemia characterized by edema in the heart, lungs, kidney, and brain. The toxin is believed to be an oligomeric pore-forming toxin. Currently, there is no effective therapy for countering the cytotoxic activity of the toxin in exposed individuals. Using a robust cell-based high-throughput screening (HTS) assay, we screened a 151,616-compound library for the ability to inhibit ε-toxin-induced cytotoxicity. Survival of MDCK cells exposed to the toxin was assessed by addition of resazurin to detect metabolic activity in surviving cells. The hit rate for this screen was 0.6%. Following a secondary screen of each hit in triplicate and assays to eliminate false positives, we focused on three structurally-distinct compounds: an N-cycloalkylbenzamide, a furo[2,3-b]quinoline, and a 6H-anthra[1,9-cd]isoxazol. None of the three compounds appeared to inhibit toxin binding to cells or the ability of the toxin to form oligomeric complexes. Additional assays demonstrated that two of the inhibitory compounds inhibited ε-toxin-induced permeabilization of MDCK cells to propidium iodide. Furthermore, the two compounds exhibited inhibitory effects on cells pre-treated with toxin. Structural analogs of one of the inhibitors identified through the high-throughput screen were analyzed and provided initial structure-activity data. These compounds should serve as the basis for further structure-activity refinement that may lead to the development of effective anti-ε-toxin therapeutics. PMID:20721308

UV-C and hyperoxia abiotic stresses to improve healthiness of carrots: study of combined effects.

PubMed

Formica-Oliveira, Anna Carolina; Martínez-Hernández, Ginés Benito; Aguayo, Encarna; Gómez, Perla A; Artés, Francisco; Artés-Hernández, Francisco

2016-09-01

Phenolic compounds are phytochemicals with high health-promoting properties. Carrot is a vegetable highly worldwide consumed although its phenolic content is low compared to other plant products. The aim of this work was to evaluate changes in phenolic compounds in carrots caused by abiotic stresses. The phenylalanine ammonia-lyase (PAL) activity, phenolic compounds and total antioxidant capacity (TAC) changes during storage up to 72 h at 15 °C after wounding (shredding), 9 kJ UV-C m -2 pretreatment and hyperoxia (80 kPa) conditions of carrots were studied. Shredding and hyperoxia storage induced the highest phenolic compounds and TAC enhancements. Accumulation of phenolic compounds in shredded carrots could be structured in the following phases: 1st phase (<24 h): unchanged phenolic compounds levels with minimum PAL activity; 2nd phase (24-48 h): moderate phenolic increases (≈600-700 mg CAE kg -1 accumulated in 24 h) concurring with the greatest increase of PAL activity; 3nd phase (48-72 h): high phenolic increases (≈1600-2700 mg CAE kg -1 , accumulated in 24 h) while a moderate increment of PAL activity was registered. Although UV-C pretreatment of shreds reduced phenolic accumulation, 600 % increments were still registered in those samples stored under hyperoxia conditions for 72 h. However, the contents of chlorogenic acid at 72 h were 1.4-fold higher in irradiated shreds under hyperoxia compared to the same samples under air conditions.

Bilingual reading of compound words.

PubMed

Ko, In Yeong; Wang, Min; Kim, Say Young

2011-02-01

The present study investigated whether bilingual readers activate constituents of compound words in one language while processing compound words in the other language via decomposition. Two experiments using a lexical decision task were conducted with adult Korean-English bilingual readers. In Experiment 1, the lexical decision of real English compound words was more accurate when the translated compounds (the combination of the translation equivalents of the constituents) in Korean (the nontarget language) were real words than when they were nonwords. In Experiment 2, when the frequency of the second constituents of compound words in English (the target language) was manipulated, the effect of lexical status of the translated compounds was greater on the compounds with high-frequency second constituents than on those with low-frequency second constituents in the target language. Together, these results provided evidence for morphological decomposition and cross-language activation in bilingual reading of compound words.

Impact of high pressure processing on color, bioactive compounds, polyphenol oxidase activity, and microbiological attributes of pumpkin purée.

PubMed

González-Cebrino, Francisco; Durán, Rocío; Delgado-Adámez, Jonathan; Contador, Rebeca; Bernabé, Rosario Ramírez

2016-04-01

Physicochemical parameters, bioactive compounds' content (carotenoids and total phenols), total antioxidant activity, and enzymatic activity of polyphenol oxidase (PPO) were evaluated after high pressure processing (HPP) on a pumpkin purée (cv. 'Butternut'). Three pressure levels (400, 500, and 600 MPa) were combined with three holding times (200, 400, and 600 s). The applied treatments reduced the levels of total aerobic mesophilic (TAM), total psychrophilic and psychrotrophic bacteria (TPP), and molds and yeasts (M&Y). All applied treatments did not affect enzymatic activity of PPO. Pressure level increased CIE L* values, which could enhance the lightness perception of high pressure (HP)-treated purées. No differences were found between the untreated and HP-treated purées regarding total phenols and carotenoids content (lutein, α-carotene, and β-carotene) and total antioxidant activity. HPP did not affect most quality parameters and maintained the levels of bioactive compounds. However, it did not achieve the complete inhibition of PPO, which could reduce the shelf-life of the pumpkin purée. © The Author(s) 2015.

Synthesis, spectroscopic characterization, DFT study and antimicrobial activity of novel alkylaminopyrazole derivatives

NASA Astrophysics Data System (ADS)

Zalaru, Christina; Dumitrascu, Florea; Draghici, Constantin; Tarcomnicu, Isabela; Tatia, Rodica; Moldovan, Lucia; Chifiriuc, Mariana-Carmen; Lazar, Veronica; Marinescu, Maria; Nitulescu, Mihai George; Ferbinteanu, Marilena

2018-03-01

A new series of substituted N,N-bis-[(1H-pyrazol-1-yl)methyl]-aminohexadecane Mannich bases were synthesized, characterized by IR, 1H NMR 13C NMR, UV-Vis, MS and elemental analysis, and tested for their biological activity. All the synthesized compounds were tested for in vitro antimicrobial activity against a panel of selected bacterial and fungal strains using erythromycin and clotrimazole as standards. Most of the synthesized compounds demonstrated very good activity at minimum inhibitory concentrations (MICs). Compound 3b with an halogen atom into the pharmacophore structure exhibited the most significant activity against Bacillus subtilis (MIC = 0.007 μgmLL-1) versus erythromycin as standard. In vitro cytotoxicity of the new compounds was studied using MTT assay. The analysis of the test cells showed that the newly synthesized alkylaminopyrazoles derivatives were biocompatible until a concentration of 5 μgmL-1; two compounds presented a high degree of biocompatibility on the studied concentration range.

Structural analysis and antimicrobial activity of 2[1H]-pyrimidinethione/selenone derivatives

NASA Astrophysics Data System (ADS)

Żesławska, Ewa; Korona-Głowniak, Izabela; Szczesio, Małgorzata; Olczak, Andrzej; Żylewska, Alicja; Tejchman, Waldemar; Malm, Anna

2017-08-01

Four new crystal structures of sulfur and selenium analogues of 2[1H]-pyrimidinone derivatives were determined with the use of X-ray diffraction method. The molecular geometry and intermolecular interactions of the investigated molecules were analyzed in order to find the structural features and geometrical parameters, which can be responsible for antimicrobial activities. The influence of chalcogen substituents (sulfur and selenium) on the crystal packing was also studied. The main differences in the molecular structures exist in mutual arrangement of two aromatic rings. The intermolecular interactions in all investigated compounds are similar. Furthermore, the in vitro antibacterial and antifungal activities for these compounds were evaluated. Preliminary investigations have identified two highly potent antibacterial compounds containing selenium atom, which display selectivity towards staphylococci and micrococci. This selectivity was not observed for a control compound used as a drug, namely vancomycin. These compounds possess also good antifungal activity. This is the first report of biological activities of 2[1H]-pyrimidineselenone derivatives.

Antibacterial, anti-inflammatory and anti-oxidatant activities of various isolated compounds from Cratoxylum species.

PubMed

Rodanant, Pirasut; Boonnak, Nawong; Surarit, Rudee; Kuvatanasuchati, Jintakorn; Lertsooksawat, Wannee

2017-05-01

The objective of this study was to investigate the bioactivity of twenty-nine known isolated compounds from Cratoxylum species including three anthraquinones, four triterpenes, and twenty-two xanthones. All isolated compounds were subjected to antibacterial, anti-inflammatory and anti-oxidant activities. Cytotoxicity evaluations were performed by MTT assay. The anti-oxidatant activity was performed using DPPH assay. The anti-inflammatory activity was evaluated from the production of cytokines TNF-α and IL1-β using ELISA assay. Human gingival fibroblasts and monocytes could tolerate both anthraquinones and triterpenes. All isolated anthraquinones showed moderate-to-high antibacterial efficacy while compound A3 also demonstrated moderate anti-inflammatory effect. None of the isolated triterpenes, except for T1, inhibited the expression of TNF-α. A number of isolated xanthones was toxic to HGFs and monocytes. Compound X5, X14 and a 1:1 mixture of X5 and X6 showed comparative anti-inflammatory activity to dexamethasone. Several triterpene and xanthone compounds also expressed antibacterial effect against P. gingivalis. Some isolated xanthones exerted anti-oxidant activity comparable to ascorbic acid. Accordingly, selected pure compounds from plants of Cratoxylum genus might be of benefit in developing medications that are important in treating periodontal diseases.

Facile synthesis and antibacterial, antitubercular, and anticancer activities of novel 1,4-dihydropyridines.

PubMed

Sirisha, Kalam; Achaiah, Garlapati; Reddy, Vanga Malla

2010-06-01

A series of twenty new 4-substituted-2,6-dimethyl-3,5-bis-N-(heteroaryl)-carbamoyl-1,4-dihydropyridines have been prepared from a three-component one-pot condensation reaction of N-heteroaryl acetoacetamide, an aromatic/heteroaromatic aldehyde, and ammonium acetate under four different experimental conditions. Except for the conventional method, all the experimental conditions were simple, eco-friendly, economical, and the reactions were rapid and high-yielding. The methods employed have been compared in terms of yields, cost, and simplicity. The synthesized compounds were characterized by different spectroscopic techniques and evaluated for their in-vitro anticancer, antibacterial, and antitubercular activities. Amongst the compounds tested, compound 25 exhibited the highest anticancer activity while compounds 14 and 18 exhibited significant antibacterial and antitubercular activities.

Synthesis, SAR and molecular docking studies of benzo[d]thiazole-hydrazones as potential antibacterial and antifungal agents.

PubMed

Zha, Gao-Feng; Leng, Jing; Darshini, N; Shubhavathi, T; Vivek, H K; Asiri, Abdullah M; Marwani, Hadi M; Rakesh, K P; Mallesha, N; Qin, Hua-Li

2017-07-15

A series of new benzo[d]thiazole-hydrazones analogues were synthesized and screened for their in vitro antibacterial and antifungal activities. The results revealed that compounds 13, 14, 15, 19, 20, 28 and 30 exhibited superior antibacterial potency compared to the reference drug chloramphenicol and rifampicin. Compounds 5, 9, 10, 11, 12, 28 and 30 were found to be good antifungal activity compared to the standard drug ketoconazole. A preliminary study of the structure-activity relationship (SAR) revealed that the antimicrobial activity depended on the effect of different substituents on the phenyl ring. The electron donating (OH and OCH 3 ) groups presented in the analogues, increase the antibacterial activity (except compound 12), interestingly, while the electron withdrawing (Cl, NO 2 , F and Br) groups increase the antifungal activity (except compound 19 and 20). In addition, analogues containing thiophene (28) and indole (30) showed good antimicrobial activities. Whereas, aliphatic analogues (24-26) shown no activities in both bacterial and fungal stains even in high concentrations (100µg/mL). Molecular docking studies were performed for all the synthesized compounds of which compounds 11, 19 and 20 showed the highest glide G-score. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trypanocidal and Leishmanicidal Activities of Sesquiterpene Lactones from Ambrosia tenuifolia Sprengel (Asteraceae) ▿

PubMed Central

Sülsen, Valeria P.; Frank, Fernanda M.; Cazorla, Silvia I.; Anesini, Claudia A.; Malchiodi, Emilio L.; Freixa, Blanca; Vila, Roser; Muschietti, Liliana V.; Martino, Virginia S.

2008-01-01

Bioassay-guided fractionation of the organic extract of Ambrosia tenuifolia Sprengel (Asteraceae) led to the isolation of two bioactive sesquiterpene lactones with significant trypanocidal and leishmanicidal activities. By spectroscopic methods (1H- and 13C-nuclear magnetic resonance, distortionless enhancement by polarization transfer, correlated spectroscopy, heteronuclear multiple-quantum coherence, electron impact-mass spectrometry, and infrared spectroscopy), these compounds were identified as psilostachyin and peruvin. Both compounds showed a marked in vitro trypanocidal activity against Trypanosoma cruzi epimastigotes with 50% inhibitory concentration (IC50) values of less than 2 μg/ml. Psilostachyin exerted a significant in vitro activity against the trypomastigote forms of T. cruzi (IC50, 0.76 μg/ml) and was selected for in vivo testing. Psilostachyin-treated mice had a survival of 100% and lower parasitemia values than control mice. Both compounds were also tested on Leishmania sp. promastigotes: psilostachyin (IC50, 0.12 μg/ml) and peruvin (IC50, 0.39 μg/ml) exerted significant leishmanicidal activities. This is the first time that the trypanocidal and leishmanicidal activities of these compounds have been reported. The selectivity index (SI) was employed to evaluate the cytotoxic effect of lactones on T lymphocytes. Although the SIs of both compounds were high for T. cruzi epimastigotes, psilostachyin was more selective against trypomastigotes (SI, 33.8) while peruvin showed no specificity for this parasite. Both compounds presented high selectivity for Leishmania spp. The results shown herein suggest that psilostachyin and peruvin could be considered potential candidates for the development of new antiprotozoal agents against Chagas' disease and leishmaniasis. PMID:18443111

Phytotoxicity of vulpia residues: III. Biological activity of identified allelochemicals from Vulpia myuros.

PubMed

An, M; Pratley, J E; Haig, T

2001-02-01

Twenty compounds identified in vulpia (Vulpia myuros) residues as allelochemicals were individually and collectively tested for biological activity. Each exhibited characteristic allelochemical behavior toward the test plant, i.e., inhibition at high concentrations and stimulation or no effect at low concentrations, but individual activities varied. Allelopathins present in large quantities, such as syringic, vanillic, and succinic acids, possessed low activity, while those present in small quantities, such as catechol and hydrocinnamic acid, possessed strong inhibitory activity. The concept of a phytotoxic strength index was developed for quantifying the biological properties of each individual allelopathin in a concise, comprehensive, and meaningful format. The individual contribution of each allelopathin, assessed by comparing the phytotoxic strength index to the overall toxicity of vulpia residues, was variable according to structure and was influenced by its relative proportion in the residue. The majority of compounds possessed low or medium biological activity and contributed most of the vulpia phytotoxicity, while compounds with high biological activity were in the minority and only present at low concentration. Artificial mixtures of these pure allelochemicals also produced phytotoxicity. There were additive/synergistic effects evident in the properties of these mixtures. One such mixture, formulated from allelochemicals found in the same proportions as occur in vulpia extract, produced stronger activity than another formulated from the same set of compounds but in equal proportions. These results suggest that the exploration of the relative composition of a cluster of allelopathins may be more important than simply focusing on the identification of one or two compounds with strong biological activity and that synergism is fundamental to the understanding of allelopathy.

A systematic study of mitochondrial toxicity of environmental chemicals using quantitative high throughput screening

PubMed Central

Attene-Ramos, Matias S.; Huang, Ruili; Sakamuru, Srilatha; Witt, Kristine L.; Beeson, Gyda C.; Shou, Louie; Schnellmann, Rick G.; Beeson, Craig C.; Tice, Raymond R.; Austin, Christopher P.; Xia, Menghang

2014-01-01

A goal of the Tox21 program is to transit toxicity testing from traditional in vivo models to in vitro assays that assess how chemicals affect cellular responses and toxicity pathways. A critical contribution of the NIH Chemical Genomics center (NCGC) to the Tox21 program is the implementation of a quantitative high throughput screening (qHTS) approach, using cell- and biochemical-based assays to generate toxicological profiles for thousands of environmental compounds. Here, we evaluated the effect of chemical compounds on mitochondrial membrane potential in HepG2 cells by screening a library of 1,408 compounds provided by the National Toxicology Program (NTP) in a qHTS platform. Compounds were screened over 14 concentrations, and results showed that 91 and 88 compounds disrupted mitochondrial membrane potential after treatment for one or five h, respectively. Seventy-six compounds active at both time points were clustered by structural similarity, producing 11 clusters and 23 singletons. Thirty-eight compounds covering most of the active chemical space were more extensively evaluated. Thirty-six of the 38 compounds were confirmed to disrupt mitochondrial membrane potential using a fluorescence plate reader and 35 were confirmed using a high content imaging approach. Among the 38 compounds, 4 and 6 induced LDH release, a measure of cytotoxicity, at 1 or 5 h, respectively. Compounds were further assessed for mechanism of action (MOA) by measuring changes in oxygen consumption rate, which enabled identification of 20 compounds as uncouplers. This comprehensive approach allows for evaluation of thousands of environmental chemicals for mitochondrial toxicity and identification of possible MOAs. PMID:23895456

Key structural features of nonsteroidal ligands for binding and activation of the androgen receptor.

PubMed

Yin, Donghua; He, Yali; Perera, Minoli A; Hong, Seoung Soo; Marhefka, Craig; Stourman, Nina; Kirkovsky, Leonid; Miller, Duane D; Dalton, James T

2003-01-01

The purposes of the present studies were to examine the androgen receptor (AR) binding ability and in vitro functional activity of multiple series of nonsteroidal compounds derived from known antiandrogen pharmacophores and to investigate the structure-activity relationships (SARs) of these nonsteroidal compounds. The AR binding properties of sixty-five nonsteroidal compounds were assessed by a radioligand competitive binding assay with the use of cytosolic AR prepared from rat prostates. The AR agonist and antagonist activities of high-affinity ligands were determined by the ability of the ligand to regulate AR-mediated transcriptional activation in cultured CV-1 cells, using a cotransfection assay. Nonsteroidal compounds with diverse structural features demonstrated a wide range of binding affinity for the AR. Ten compounds, mainly from the bicalutamide-related series, showed a binding affinity superior to the structural pharmacophore from which they were derived. Several SARs regarding nonsteroidal AR binding were revealed from the binding data, including stereoisomeric conformation, steric effect, and electronic effect. The functional activity of high-affinity ligands ranged from antagonist to full agonist for the AR. Several structural features were found to be determinative of agonist and antagonist activities. The nonsteroidal AR agonists identified from the present studies provided a pool of candidates for further development of selective androgen receptor modulators (SARMs) for androgen therapy. Also, these studies uncovered or confirmed numerous important SARs governing AR binding and functional properties by nonsteroidal molecules, which would be valuable in the future structural optimization of SARMs.

A Screening Assay Based on Host-Pathogen Interaction Models Identifies a Set of Novel Antifungal Benzimidazole Derivatives▿

PubMed Central

Burger-Kentischer, Anke; Finkelmeier, Doris; Keller, Petra; Bauer, Jörg; Eickhoff, Holger; Kleymann, Gerald; Abu Rayyan, Walid; Singh, Anurag; Schröppel, Klaus; Lemuth, Karin; Wiesmüller, Karl-Heinz; Rupp, Steffen

2011-01-01

Fungal infections are a serious health problem in clinics, especially in the immune-compromised patient. Disease ranges from widespread superficial infections like vulvovaginal infections to life-threatening systemic candidiasis. Especially for systemic mycoses, only a limited arsenal of antifungals is available. The most commonly used classes of antifungal compounds used include azoles, polyenes, and echinocandins. Due to emerging resistance to standard therapy, significant side effects, and high costs for several antifungals, there is a medical need for new antifungals in the clinic and general practice. In order to expand the arsenal of compounds with antifungal activities, we screened a compound library including more than 35,000 individual compounds derived from organic synthesis as well as combinatorial compound collections representing mixtures of compounds for antimycotic activity. In total, more than 100,000 compounds were screened using a new type of activity-selectivity assay, analyzing both the antifungal activity and the compatibility with human cells at the same time. One promising hit, an (S)-2-aminoalkyl benzimidazole derivative, was developed among a series of lead compounds showing potent antifungal activity. (S)-2-(1-Aminoisobutyl)-1-(3-chlorobenzyl) benzimidazole showed the highest antifungal activity and the best compatibility with human cells in several cell culture models and against a number of clinical isolates of several species of pathogenic Candida yeasts. Transcriptional profiling indicates that the newly discovered compound is a potential inhibitor of the ergosterol pathway, in contrast to other benzimidazole derivatives, which target microtubules. PMID:21746957

Synthesis and antimicrobial activity of new 1-[(tetrazol-5-yl)methyl] indole derivatives, their 1,2,4-triazole thioglycosides and acyclic analogs.

PubMed

El-Sayed, Weal A; Abdel Megeid, Randa E; Abbas, Hebat-Allah S

2011-07-01

New 1-[(tetrazol-5-yl)methyl]indole derivatives, their acyclic nucleoside analogs and the corresponding glycoside derivatives were synthesized. Furthermore, the [)(1,2,4-triazol-3-yl)methyl])-2H-tetrazole derivative as well as the corresponding thioglucoside were prepared. The synthesized compounds were tested for their antimicrobial activity against Aspergillus Niger, Penicillium sp, Candida albican, Bacillus subtilis, Streptococcus lacti, Escherichia coli, Pseudomonas sp., and streptomyces sp. Compounds 3, 5 and 19b exhibited potent antibacterial activity and compounds 4, 5 and 10 exhibited high activities against the tested fungi compared with fusidic acid.

Rechargeable quasi-solid state lithium battery with organic crystalline cathode

PubMed Central

Hanyu, Yuki; Honma, Itaru

2012-01-01

Utilization of metal-free low-cost high-capacity organic cathodes for lithium batteries has been a long-standing goal, but critical cyclability problems owing to dissolution of active materials into the electrolyte have been an inevitable obstacle. For practical utilisation of numerous cathode-active compounds proposed over the past decades, a novel battery construction strategy is required. We have designed a solid state cell that accommodates organic cathodic reactions in solid phase. The cell was successful at achieving high capacity exceeding 200 mAh/g with excellent cycleability. Further investigations confirmed that our strategy is effective for numerous other redox-active organic compounds. This implies hundreds of compounds dismissed before due to low cycleability would worth a re-visit under solid state design. PMID:22693655

Assessment of India’s Research Literature

DTIC Science & Technology

2006-01-01

promastigotes. • (19) [inhibitor 16.0%, acid 6.4%, amino 3.5%, activ 3.5%, antibacteri 3.1%, trypsin 2.9%, amino.acid 2.0%, chymotrypsin...substitut 2.1%] – Antibacterial and antifungal activity in compounds, particularly screening for such activity • (46) [compound 44.0%, activ 2.9...studies, and its presence in the midst of the high tech top tier countries stands out. The presence of Philippines in this list has strong reasons

Biological Activities of Extracts from Loquat (Eriobotrya japonica Lindl.): A Review

PubMed Central

Liu, Yilong; Zhang, Wenna; Xu, Changjie; Li, Xian

2016-01-01

Loquat (Eriobotrya japonica Lindl.) is a subtropical fruit tree with high medicinal value native to China. Different organs of loquat have been used historically as folk medicines and this has been recorded in Chinese history for thousands of years. Research shows that loquat extracts contain many antioxidants, and different extracts exhibit bioactivity capable of counteracting inflammation, diabetes, cancer, bacterial infection, aging, pain, allergy and other health issues. Bioactive compounds such as phenolics and terpenoids have been isolated and characterized to provide a better understanding of the chemical mechanisms underlying the biological activities of loquat extracts. As the identification of compounds progresses, studies investigating the in vivo metabolism, bioavailability, and structure–activity relationships, as well as potential toxicity of loquat extracts in animal or cell models are receiving more attention. In addition, genetic studies and breeding of loquat germplasms for high contents of health-benefiting compounds may provide new insight for the loquat industry and research. This review is focused on the main medicinal properties reported and the possible pharmaceutically active compounds identified in different loquat extracts. PMID:27929430

High-throughput screening of a diversity collection using biodefense category A and B priority pathogens.

PubMed

Barrow, Esther W; Clinkenbeard, Patricia A; Duncan-Decocq, Rebecca A; Perteet, Rachel F; Hill, Kimberly D; Bourne, Philip C; Valderas, Michelle W; Bourne, Christina R; Clarkson, Nicole L; Clinkenbeard, Kenneth D; Barrow, William W

2012-08-01

One of the objectives of the National Institutes of Allergy and Infectious Diseases (NIAID) Biodefense Program is to identify or develop broad-spectrum antimicrobials for use against bioterrorism pathogens and emerging infectious agents. As a part of that program, our institution has screened the 10 000-compound MyriaScreen Diversity Collection of high-purity druglike compounds against three NIAID category A and one category B priority pathogens in an effort to identify potential compound classes for further drug development. The effective use of a Clinical and Laboratory Standards Institute-based high-throughput screening (HTS) 96-well-based format allowed for the identification of 49 compounds that had in vitro activity against all four pathogens with minimum inhibitory concentration values of ≤16 µg/mL. Adaptation of the HTS process was necessary to conduct the work in higher-level containment, in this case, biosafety level 3. Examination of chemical scaffolds shared by some of the 49 compounds and assessment of available chemical databases indicates that several may represent broad-spectrum antimicrobials whose activity is based on novel mechanisms of action.

Characterization of the Key Aroma Compounds in Proso Millet Wine Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry.

PubMed

Liu, Jingke; Zhao, Wei; Li, Shaohui; Zhang, Aixia; Zhang, Yuzong; Liu, Songyan

2018-02-20

The volatile compounds in proso millet wine were extracted by headspace solid-phase microextraction (85 μm polyacrylate (PA), 100 μm polydimethylsiloxane (PDMS), 75 μm Carboxen (CAR)/PDMS, and 50/30 μm divinylbenzene (DVB)/CAR/PDMS fibers), and analyzed using gas chromatography-mass spectrometry; the odor characteristics and intensities were analyzed by the odor activity value (OAV). Different sample preparation factors were used to optimize this method: sample amount, extraction time, extraction temperature, and content of NaCl. A total of 64 volatile compounds were identified from the wine sample, including 14 esters, seven alcohols, five aldehydes, five ketones, 12 benzene derivatives, 12 hydrocarbons, two terpenes, three phenols, two acids, and two heterocycles. Ethyl benzeneacetate, phenylethyl alcohol, and benzaldehyde were the main volatile compounds found in the samples. According to their OAVs, 14 volatile compounds were determined to be odor-active compounds (OAV > 1), and benzaldehyde, benzeneacetaldehyde, 1-methyl-naphthalene, 2-methyl-naphthalene, and biphenyl were the prominent odor-active compounds (OAV > 50), having a high OAV. Principal component analysis (PCA) showed the difference of distribution of the 64 volatile compounds and 14 odor-active compounds with four solid-phase microextraction (SPME) fibers.

Prediction of new bioactive molecules using a Bayesian belief network.

PubMed

Abdo, Ammar; Leclère, Valérie; Jacques, Philippe; Salim, Naomie; Pupin, Maude

2014-01-27

Natural products and synthetic compounds are a valuable source of new small molecules leading to novel drugs to cure diseases. However identifying new biologically active small molecules is still a challenge. In this paper, we introduce a new activity prediction approach using Bayesian belief network for classification (BBNC). The roots of the network are the fragments composing a compound. The leaves are, on one side, the activities to predict and, on another side, the unknown compound. The activities are represented by sets of known compounds, and sets of inactive compounds are also used. We calculated a similarity between an unknown compound and each activity class. The more similar activity is assigned to the unknown compound. We applied this new approach on eight well-known data sets extracted from the literature and compared its performance to three classical machine learning algorithms. Experiments showed that BBNC provides interesting prediction rates (from 79% accuracy for high diverse data sets to 99% for low diverse ones) with a short time calculation. Experiments also showed that BBNC is particularly effective for homogeneous data sets but has been found to perform less well with structurally heterogeneous sets. However, it is important to stress that we believe that using several approaches whenever possible for activity prediction can often give a broader understanding of the data than using only one approach alone. Thus, BBNC is a useful addition to the computational chemist's toolbox.

Development of an Intracellular Screen for New Compounds Able To Inhibit Mycobacterium tuberculosis Growth in Human Macrophages.

PubMed

Sorrentino, Flavia; Gonzalez del Rio, Ruben; Zheng, Xingji; Presa Matilla, Jesus; Torres Gomez, Pedro; Martinez Hoyos, Maria; Perez Herran, Maria Esther; Mendoza Losana, Alfonso; Av-Gay, Yossef

2016-01-01

Here we describe the development and validation of an intracellular high-throughput screening assay for finding new antituberculosis compounds active in human macrophages. The assay consists of a luciferase-based primary identification assay, followed by a green fluorescent protein-based secondary profiling assay. Standard tuberculosis drugs and 158 previously recognized active antimycobacterial compounds were used to evaluate assay robustness. Data show that the assay developed is a short and valuable tool for the discovery of new antimycobacterial compounds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Molecular simplification of 1,4-diazabicyclo[4.3.0]nonan-9-ones gives piperazine derivatives that maintain high nootropic activity.

PubMed

Manetti, D; Ghelardini, C; Bartolini, A; Dei, S; Galeotti, N; Gualtieri, F; Romanelli, M N; Teodori, E

2000-11-16

Several 4-substituted 1-acylpiperazines, obtained by molecular simplification of 4-substituted 1,4-diazabicyclo[4.3.0]nonan-9-ones, have been synthesized and tested in vivo on the mouse passive avoidance test, to evaluate their nootropic activity. The results show that, apparently, an N-acylpiperazine group can mimic the 2-pyrrolidinone ring of 1,4-diazabicyclo[4.3.0]nonan-9-one, as the compounds of the new series maintain high nootropic activity. Moreover molecular simplification produces more clear-cut structure-activity relationships with respect to the parent series. The mechanism of action also appears to be similar in the two series. In fact, although the molecular mechanism remains to be elucidated, the most potent compound of each class (DM232 and 13, DM235) is able to increase acetylcholine release in rat brain. Piperazine derivatives represent a new class of nootropic drugs with an in vivo pharmacological profile very similar to that of piracetam, showing much higher potency with respect to the reference compound. Among the compounds studied, 13 (DM235) shows outstanding potency, being active at a dose of 0.001 mg kg(-1) sc.

Bioactive compounds in bee propolis for drug discovery

NASA Astrophysics Data System (ADS)

Kumazawa, Shigenori

2018-02-01

Propolis is a natural resinous product collected by honeybees. It has been used in folk medicine since ancient times because of its numerous biological properties such as antioxidant, antimicrobial, anti-cancer, and anti-inflammatory activities. Studies of the chemical composition of propolis have demonstrated that its compositional variability depends on the source plant. We have studied the chemistry and biological activities of various types of propolis from Apis mellifera. The studies of propolis collected in Brazil, Japan, Korea, the Solomon Island and Senegal are summarized. Brazilian green propolis contained high levels of artepillin C (3,5-diprenyl-4-hydroxycinnamic acid), which has a potent apoptosis-inducing agent as well as an angiogenesis inhibitor. The several phenolic compounds with potent antibacterial activity in Brazilian red propolis were found. The propolis from Okinawa, Japan, contained some prenylflavonoids with antioxidant and antimicrobial activities. The propolis from the Solomon Islands and Hawaii have the same compounds as Okinawan propolis. The propolis from Jeju Island, Korea had the promotion effect on nerve growth factor (NGF) secretion in human glioblastoma T98G cells. The compounds isolated from Senegalese propolis showed high anti-inflammatory activity due to their inhibition of the liposaccharide (LPS)-induced expression of inducible NO synthase (iNOS).

Conventional and microwave-assisted synthesis of new indole-tethered benzimidazole-based 1,2,3-triazoles and evaluation of their antimycobacterial, antioxidant and antimicrobial activities.

PubMed

Ashok, Dongamanti; Gundu, Srinivas; Aamate, Vikas Kumar; Devulapally, Mohan Gandhi

2018-04-18

A new series of triheterocycles containing indole-benzimidazole-based 1,2,3-triazole hybrids have been synthesized in good yields via a microwave-assisted click reaction. All the compounds were characterized by IR, [Formula: see text] NMR, [Formula: see text] NMR and mass spectroscopy and were evaluated for their in vitro antitubercular activity against the Mycobacterium tuberculosis H37Rv strain. Compounds 4b, 4h and 4i displayed highly potent antitubercular activity with MIC 3.125-6.25 [Formula: see text]. The antioxidant potential was evaluated using 2,2-diphenyl-1-picryl hydrazine and [Formula: see text] radical scavenging activity, and compounds 4e,4f and 4g showed excellent radical scavenging activity with [Formula: see text] values in the range of 08.50-10.05 [Formula: see text]. Furthermore, the compounds were evaluated for antimicrobial activity against numerous bacterial and fungal strains, and compounds 4b, 4c and 4h were found to be the most promising potential antimicrobial molecules with MIC 3.125-6.25 [Formula: see text].

Novel KCNQ2 channel activators discovered using fluorescence-based and automated patch-clamp-based high-throughput screening techniques

PubMed Central

Yue, Jin-feng; Qiao, Guan-hua; Liu, Ni; Nan, Fa-jun; Gao, Zhao-bing

2016-01-01

Aim: To establish an improved, high-throughput screening techniques for identifying novel KCNQ2 channel activators. Methods: KCNQ2 channels were stably expressed in CHO cells (KCNQ2 cells). Thallium flux assay was used for primary screening, and 384-well automated patch-clamp IonWorks Barracuda was used for hit validation. Two validated activators were characterized using a conventional patch-clamp recording technique. Results: From a collection of 80 000 compounds, the primary screening revealed a total of 565 compounds that potentiated the fluorescence signals in thallium flux assay by more than 150%. When the 565 hits were examined in IonWorks Barracuda, 38 compounds significantly enhanced the outward currents recorded in KCNQ2 cells, and were confirmed as KCNQ2 activators. In the conventional patch-clamp recordings, two validated activators ZG1732 and ZG2083 enhanced KCNQ2 currents with EC50 values of 1.04±0.18 μmol/L and 1.37±0.06 μmol/L, respectively. Conclusion: The combination of thallium flux assay and IonWorks Barracuda assay is an efficient high-throughput screening (HTS) route for discovering KCNQ2 activators. PMID:26725738

1,1-Diphenyl-2-picrylhydrazyl radical-scavenging compounds from soybean miso and antiproliferative activity of isoflavones from soybean miso toward the cancer cell lines.

PubMed

Hirota, A; Taki, S; Kawaii, S; Yano, M; Abe, N

2000-05-01

Guided by their DPPH radical-scavenging activity, nine compounds were isolated from soybean miso. Of these, 8-hydroxydaidzein, 8-hydroxygenistein and syringic acid had as high DPPH radical-scavenging activity as that of alpha-tocopherol. The antiproliferative activity of four of the isolated isoflavones toward three cancer cell lines was examined. 8-Hydroxygenistein showed the highest activity (IC50=5.2 microM) toward human promyelocytic leukemia cells (HL-60).

Synthesis, molecular docking, DFT calculations and cytotoxicity activity of benzo[g]quinazoline derivatives in choline chloride-urea

NASA Astrophysics Data System (ADS)

Lakshmanan, Sivalingam; Govindaraj, Dharman; Ramalakshmi, Narayanan; Antony, S. Arul

2017-12-01

Green and highly efficient one-pot three component approach for the synthesis of benzo[g]quinazoline derivatives (6a-g) using Choline chloride-urea (DES). Synthesized compounds 6b and 6g showed the most potent biological activity against A549 lung cancer cell line. Docking simulation was performed to position compounds 6b and 6g showed the greater affinity for anaplastic lymphoma kinase (ALK) receptor. Quantum chemical studies were carried out on these compounds to understand the structural features essential for activity using DFT/6-31G level of theory.

Activating Student to Learn Chemistry using Chemmy Card 6-1 Game as an Instructional Medium in IUPAC Nomenclature of Inorganic Compounds

NASA Astrophysics Data System (ADS)

Lutfi, A.; Hidayah, R.

2018-01-01

The aim of this study is to know the effect of Internet-assisted Chemmy Card 6-1 game as an instructional medium in IUPAC Nomenclature of Inorganic Compounds material for X grade of senior high school on students’ activity, learning motivation, and learning outcome. The study was conducted at SMA Negeri Sidoarjo, Indonesia, in two different classes. The instruction was done based on the lesson plan made. The observation on students’ activity was conducted during the instruction with the game while test and questionnaire were given after the instruction. The result showed positive activities, which students listened to the teacher’s explanation, actively delivered questions, and enabled to solve problems in naming compounds. It was also effective to avoid the drowsiness. The result of students’ motivation of X MIPA 6 was 74.78% (good) while X MIPA 7 was 83.80% (very good). The pretest results of two classes showed that no students mastered but 100% students mastered and the increase of N-gain scores in two classes was categorized as high, ≥0,7, after the instruction. The result of this study showed that the use of Internet-assisted Chemmy Card 6-1 game in IUPAC nomenclature of inorganic compounds for X grade of senior high school could be pleasant for students to learn and effective in achieving the learning objective.

Discovery of peroxisome proliferator-activated receptor α (PPARα) activators with a ligand-screening system using a human PPARα-expressing cell line.

PubMed

Tachibana, Keisuke; Yuzuriha, Tomohiro; Tabata, Ryotaro; Fukuda, Syohei; Maegawa, Takashi; Takahashi, Rika; Tanimoto, Keiichi; Tsujino, Hirofumi; Nunomura, Kazuto; Lin, Bangzhong; Matsuura, Yoshiharu; Tanaka, Toshiya; Hamakubo, Takao; Sakai, Juro Js; Kodama, Tatsuhiko; Kobayashi, Tadayuki; Ishimoto, Kenji; Miyachi, Hiroyuki; Doi, Takefumi

2018-05-15

Peroxisome proliferator-activated receptor alpha (PPARα) is a ligand-activated transcription factor that belongs to the superfamily of nuclear hormone receptors. PPARα is mainly expressed in the liver, where it activates fatty acid oxidation and lipoprotein metabolism and improves plasma lipid profiles. Therefore, PPARα activators are often used to treat patients with dyslipidemia. To discover additional PPARα activators as potential compounds for use in hypolipidemic drugs, here we established human hepatoblastoma cell lines with luciferase reporter expression from the promoters containing peroxisome proliferator responsive elements (PPRE) and tetracycline-regulated expression of full-length human PPARα to quantify the effects of chemical ligands on PPARα activity. Using the established cell-based PPARα-activator screening system to screen a library of > 12,000 chemical compounds, we identified several hit compounds with basic chemical skeletons different from those of known PPARα agonists. One of the hit compounds, a 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivative we termed compound 3, selectively up-regulated PPARα transcriptional activity, leading to PPARα target gene expression both in vitro and in vivo. Of note, the half-maximal effective concentrations of the hit compounds were lower than that of the known PPARα ligand fenofibrate. Finally, fenofibrate or compound 3 treatment of high fructose-fed rats having elevated plasma triglyceride levels for 14 days indicated that compound 3 reduces plasma triglyceride levels with similar efficiency as fenofibrate. These observations raise the possibility that 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivatives might be effective drug candidates for selective targeting of PPARα to manage dyslipidemia. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

A workflow to investigate exposure and pharmacokinetic ...

EPA Pesticide Factsheets

Adverse outcome pathways (AOP) link known population outcomes to a molecular initiating event (MIE) that can be quantified using high-throughput in vitro methods. Practical application of AOPs in chemical-specific risk assessment requires consideration of exposure and absorption, distribution, metabolism, excretion (ADME) properties of chemicals. We developed a conceptual workflow to consider exposure and ADME properties in relationship to an MIE and demonstrated the utility of this workflow using a previously established AOP, acetylcholinesterase (AChE) inhibition. Thirty active chemicals found to inhibit AChE in the ToxCastTM assay were examined with respect to their exposure and absorption potentials, and their ability to cross the blood-brain barrier. Structural similarities of active compounds were compared against structures of inactive compounds to detect possible non-active parents that might have active metabolites. Fifty-two of the 1,029 inactive compounds exhibited a similarity threshold above 75% with their nearest active neighbors. Excluding compounds that may not be absorbed, 22 could be potentially toxic following metabolism. The incorporation of exposure and ADME properties into the conceptual workflow resulted in prioritization of 20 out of 30 active compounds identified in an AChE inhibition assay for further analysis, along with identification of several inactive parent compounds of active metabolites. This qualitative approach can minimize co

Can we conserve trans-resveratrol content and antioxidant activity during industrial production of chocolate?

PubMed

Salvador, Izabela; Massarioli, Adna P; Silva, Anna Paula S; Malaguetta, Heloísa; Melo, Priscilla S; Alencar, Severino M

2018-05-23

Cocoa exhibits high content of phenolic compounds, among which trans-resveratrol stands out, associated with several bioactive activities such as antioxidant properties. Chocolate contains reduced amounts of these bioactive compounds due to losses during the production process. Therefore, this study aimed to assess changes in total phenolic content and specifically trans-resveratrol, as well as in the antioxidant activity of cocoa and its products during industrial production of chocolate. A total of ten different cocoa products were analyzed. The processes of fermentation and roasting caused significant loss of total phenolic compounds and antioxidant activity. However, due to high temperature, roasting had a major influence on this loss (71% for total phenolic compounds and 53% to 77% for antioxidant activity), except for trans-resveratrol. The content of trans-resveratrol formed after fermentation (9.8 μg kg -1 ) showed little variation during the processes, and it was detected in higher concentrations both in natural (11.4 μg kg -1 ) and in alkalized cocoa powder (13.5 μg kg -1 ). Alkalization of cocoa products led to loss of capacity of deactivating superoxide radical. These findings contribute to the optimization of the production process of chocolate and other food products containing cocoa and its derivatives aiming to better preserve their bioactive compounds. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Isolation and structural characterisation of two antibacterial free fatty acids from the marine diatom, Phaeodactylum tricornutum.

PubMed

Desbois, Andrew P; Lebl, Tomas; Yan, Liming; Smith, Valerie J

2008-12-01

One solution to the global crisis of antibiotic resistance is the discovery of novel antimicrobial compounds for clinical application. Marine organisms are an attractive and, as yet, relatively untapped resource of new natural products. Cell extracts from the marine diatom, Phaeodactylum tricornutum, have antibacterial activity and the fatty acid, eicosapentaenoic acid (EPA), has been identified as one compound responsible for this activity. During the isolation of EPA, it became apparent that the extracts contained further antibacterial compounds. The present study was undertaken to isolate these additional antibacterial factors using silica column chromatography and reverse-phase high-performance liquid chromatography. Two antibacterial fractions, each containing a pure compound, were isolated and their chemical structures were investigated by mass spectrometry and nuclear magnetic resonance spectroscopy. The antibacterial compounds were identified as the monounsaturated fatty acid (9Z)-hexadecenoic acid (palmitoleic acid; C16:1 n-7) and the relatively unusual polyunsaturated fatty acid (6Z, 9Z, 12Z)-hexadecatrienoic acid (HTA; C16:3 n-4). Both are active against Gram-positive bacteria with HTA further inhibitory to the growth of the Gram-negative marine pathogen, Listonella anguillarum. Palmitoleic acid is active at micro-molar concentrations, kills bacteria rapidly, and is highly active against multidrug-resistant Staphylococcus aureus. These free fatty acids warrant further investigation as a new potential therapy for drug-resistant infections.

Identification of chalcone-based antileishmanial agents targeting trypanothione reductase.

PubMed

Ortalli, Margherita; Ilari, Andrea; Colotti, Gianni; De Ionna, Ilenia; Battista, Theo; Bisi, Alessandra; Gobbi, Silvia; Rampa, Angela; Di Martino, Rita M C; Gentilomi, Giovanna A; Varani, Stefania; Belluti, Federica

2018-05-02

All currently used first-line and second-line drugs for the treatment of leishmaniasis exhibit several drawbacks including toxicity, high costs and route of administration. Furthermore, some drugs are associated with the emergence of drug resistance. Thus, the development of new treatments for leishmaniasis is a priority in the field of neglected tropical diseases. The present work highlights the use of natural derived products, i.e. chalcones, as potential source of antileishmanial agents. Thirty-one novel chalcone compounds have been synthesized and their activity has been evaluated against promastigotes of Leishmania donovani; 16 compounds resulted active against L. donovani in a range from 3.0 to 21.5 μM, showing low toxicity against mammalian cells. Among these molecules, 6 and 16 showed good inhibitory activity on both promastigotes and intracellular amastigotes, coupled with an high selectivity index. Furthermore, compounds 6 and 16 inhibited the promastigote growth of other leishmanial species, including L. tropica, L. major and L. infantum. Finally, 6 and 16 interacted with high affinity with trypanothione reductase (TR), an essential enzyme for the leishmanial parasite and compound 6 inhibited TR with sub-micromolar potency. Thus, the effective inhibitory activity against Leishmania, the lack of toxicity on mammalian cells and the ability to block a crucial parasite's enzyme, highlight the potential for compound 6 to be optimized as novel drug candidate against leishmaniasis. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Algicidal activity of Bacillus sp. Lzh-5 and its algicidal compounds against Microcystis aeruginosa.

PubMed

Li, Zhenghua; Geng, Mengxin; Yang, Hong

2015-01-01

A freshwater algicidal bacterial strain, Lzh-5, isolated from Lake Taihu, with strong algicidal activity against Microcystis aeruginosa, was identified as Bacillus sp. based on its phenotypic characteristics and 16S ribosomal RNA (rRNA) gene sequence. The algicidal mode of Bacillus sp. Lzh-5 was indirect, attacking M. aeruginosa cells by releasing algicidal compounds. Two algicidal compounds (S-5A and S-5B) produced by Bacillus sp. Lzh-5 were purified with ethyl acetate extraction, column chromatography, and high-performance liquid chromatography and identified as hexahydropyrrolo[1,2-a]pyrazine-1,4-dione and 3-isopropyl-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione based on liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, and nuclear magnetic resonance analyses. The active algicidal compounds S-5A (hexahydropyrrolo[1,2-a]pyrazine-1,4-dione) and S-5B (3-isopropyl-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione) displayed high levels of algicidal activity against M. aeruginosa 9110, with LD50 values of 5.7 and 19.4 μg/ml, respectively. This is the first report of 3-isopropyl-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione as an algicidal compound. Compounds S-5A and S-5B also induced obvious morphological changes in M. aeruginosa 9110. In cocultures of M. aeruginosa 9110 and Bacillus sp. Lzh-5, the cell density of Bacillus sp. Lzh-5 and the concentrations of S-5A and S-5B correlated positively with the algicidal activity. Our results indicate that strain Lzh-5 and its two algicidal compounds are potentially useful for controlling cyanobacterial blooms in Lake Taihu.

Evaluation of anti-Zika virus activities of broad-spectrum antivirals and NIH clinical collection compounds using a cell-based, high-throughput screen assay.

PubMed

Adcock, Robert S; Chu, Yong-Kyu; Golden, Jennifer E; Chung, Dong-Hoon

2017-02-01

Recent studies have clearly underscored the association between Zika virus (ZIKV) and severe neurological diseases such as microcephaly and Guillain-Barre syndrome. Given the historical complacency surrounding this virus, however, no significant antiviral screenings have been performed to specifically target ZIKV. As a result, there is an urgent need for a validated screening method and strategy that is focused on highlighting potential anti-ZIKV inhibitors that can be further advanced via rigorous validation and optimization. To address this critical gap, we sought to test whether a cell-based assay that measures protection from the ZIKV-induced cytopathic effect could serve as a high-throughput screen assay for discovering novel anti-ZIKV inhibitors. Employing this approach, we tested the anti-ZIKV activity of previously known broad-spectrum antiviral compounds and discovered several compounds (e.g., NITD008, SaliPhe, and CID 91632869) with anti-ZIKV activity. Interestingly, while GTP synthesis inhibitors (e.g., ribavirin or mycophenolic acid) were too toxic or showed no anti-ZIKV activity (EC 50  > 50 μM), ZIKV was highly susceptible to pyrimidine synthesis inhibitors (e.g., brequinar) in the assay. We amended the assay into a high-throughput screen (HTS)-compatible 384-well format and then screened the NIH Clinical Compound Collection library, which includes a total of 727 compounds organized, using an 8-point dose response format with two Zika virus strains (MR766 and PRVABC59, a recent human isolate). The screen discovered 6-azauridine and finasteride as potential anti-ZIKV inhibitors with EC 50 levels of 3.18 and 9.85 μM for MR766, respectively. We further characterized the anti-ZIKV activity of 6-azauridine and several pyrimidine synthesis inhibitors such as brequinar in various secondary assays including an antiviral spectrum test within flaviviruses and alphaviruses, Western blot (protein), real-time PCR (RNA), and plaque reduction assays (progeny virus). From these assays, we discovered that brequinar has potent anti-ZIKV activity. Our results show that a broad anti-ZIKV screen of compound libraries with our CPE-based HTS assay will reveal multiple chemotypes that could be pursued as lead compounds for therapies to treat ZIKV-associated diseases or as molecular probes to study the biology of the ZIKV replication mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis and antimycobacterial screening of new thiazolyl-oxazole derivatives.

PubMed

Abhale, Yogita K; Sasane, Amit V; Chavan, Abhijit P; Shekh, Saddam Husen; Deshmukh, Keshav K; Bhansali, Sujit; Nawale, Laxman; Sarkar, Dhiman; Mhaske, Pravin C

2017-05-26

In the present study a series of 4-methyl-2-aryl-5-(2-aryl/benzyl thiazol-4-yl) oxazole (4a-v) have been synthesized and evaluated for their preliminary antitubercular, antimicrobial and cytotoxicity activity. Among all the synthesized compounds, 4v reported comparable activity against dormant M. tuberculosis H 37 Ra and M. bovis BCG strains with respect to standard drug rifampicin. The active compounds from the antitubercular study were further tested for anti-proliferative activity against HeLa, A549 and PANC-1 cell lines using MTT assay and showed no significant cytotoxic activity at the maximum concentration evaluated. Further, the synthesized compounds were found to have potential antibacterial activities with MIC range of 2.1-26.8 μg/mL. High potency, lower cytotoxicity and promising antimycobacterial activity suggested that these compounds could serve as good leads for further optimisation and development. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Anti-plasmodial activity of Dicoma tomentosa (Asteraceae) and identification of urospermal A-15-O-acetate as the main active compound

PubMed Central

2012-01-01

Background Natural products could play an important role in the challenge to discover new anti-malarial drugs. In a previous study, Dicoma tomentosa (Asteraceae) was selected for its promising anti-plasmodial activity after a preliminary screening of several plants traditionally used in Burkina Faso to treat malaria. The aim of the present study was to further investigate the anti-plasmodial properties of this plant and to isolate the active anti-plasmodial compounds. Methods Eight crude extracts obtained from D. tomentosa whole plant were tested in vitro against two Plasmodium falciparum strains (3D7 and W2) using the p-LDH assay (colorimetric method). The Peters’ four-days suppressive test model (Plasmodium berghei-infected mice) was used to evaluate the in vivo anti-plasmodial activity. An in vitro bioguided fractionation was undertaken on a dichloromethane extract, using preparative HPLC and TLC techniques. The identity of the pure compound was assessed using UV, MS and NMR spectroscopic analysis. In vitro cytotoxicity against WI38 human fibroblasts (WST-1 assay) and haemolytic activity were also evaluated for extracts and pure compounds in order to check selectivity. Results The best in vitro anti-plasmodial results were obtained with the dichloromethane, diethylether, ethylacetate and methanol extracts, which exhibited a high activity (IC50 ≤ 5 μg/ml). Hot water and hydroethanolic extracts also showed a good activity (IC50 ≤ 15 μg/ml), which confirmed the traditional use and the promising anti-malarial potential of the plant. The activity was also confirmed in vivo for all tested extracts. However, most of the active extracts also exhibited cytotoxic activity, but no extract was found to display any haemolytic activity. The bioguided fractionation process allowed to isolate and identify a sesquiterpene lactone (urospermal A-15-O-acetate) as the major anti-plasmodial compound of the plant (IC50 < 1 μg/ml against both 3D7 and W2 strains). This was also found to be the main cytotoxic compound (SI = 3.3). While this melampolide has already been described in the plant, this paper is the first report on the biological properties of this compound. Conclusions The present study highlighted the very promising anti-plasmodial activity of D. tomentosa and enabled to identify its main active compound, urospermal A-15-O-acetate. The high anti-plasmodial activity of this compound merits further study about its anti-plasmodial mechanism of action. The active extracts of D. tomentosa, as well as urospermal A 15-O-acetate, displayed only a moderate selectivity, and further studies are needed to assess the safety of the use of the plant by the local population. PMID:22909422

Water Soluble Phosphane-Gold(I) Complexes. Applications as Recyclable Catalysts in a Three-component Coupling Reaction and as Antimicrobial and Anticancer Agents

PubMed Central

Elie, Benelita T.; Levine, Chaya; Ubarretxena-Belandia, Iban; Varela-Ramírez, Armando; Aguilera, Renato J.; Ovalle, Rafael; Contel, María

2013-01-01

Water-soluble compounds of the type [AuCl(PR3)] with alkyl-bis-(m-sulfonated-phenyl)-(mC6H4SO3Na)2 and dialkyl-(m-sulfonated-phenyl)-(mC6H4SO3Na) (R = nBu, Cp) phosphanes have been prepared. Dialkyl-phosphane compounds generate water-soluble nanoparticles of 10-15 nm radius when dissolved in water. These air-stable complexes have been evaluated as catalysts in the synthesis of propargylamines via a three-component coupling reaction of aldehydes, amines and alkynes in water. The antimicrobial activity of the new complexes against Gram-positive and Gram-negative bacteria and yeast has been evaluated. The new compounds display moderate to high antibacterial activity. The more lipophilic compounds are also potent against fungi. Their cytotoxic properties have been analyzed in vitro utilizing human Jurkat T-cell acute lymphoblastic leukemia cells. Compounds with dialkyl-(m-sulfonated-phenyl)-(mC6H4SO3Na) phosphanes displayed moderate to high cytotoxicity on this cell line. Death cell mechanism occurs mainly by early apoptosis. The catalytic/biological activity of the previously described compound with commercial m-trisulfonated-triphenylphosphine [AuCl(TPPTS)] (6) has been also evaluated to compare the effects of the higher basicity and lipophilicity of the alkyl- and di-alkyl-(m-sulfonated-phenyl) phosphanes on these new compounds. PMID:23524957

Synthesis and evaluation of novel N-H and N-substituted indole-2- and 3-carboxamide derivatives as antioxidants agents.

PubMed

Olgen, Süreyya; Kiliç, Zuhal; Ada, Ahmet O; Coban, Tulay

2007-08-01

We have previously reported on the synthesis of novel indole derivatives where some compounds showed significant antioxidant activity. Here, we report the synthesis of novel N-H and N-substituted indole-2- and 3-carboxamide derivatives and investigated their antioxidant role in order to identify structural characteristics responsible for activity. Although all compounds showed a strong inhibitory (95-100%) effect on superoxide anion (SOD) only compounds 4, 5 and 6 showed simliar potency for the inhibition of lipid peroxidation (81-94%) which revealed that compounds 4, 5 and 6 possessed highly potent antioxidant properties. Substitution in the 1-position of the indole ring caused the significant differences between the activity results regarding lipid peroxidation inhibition.

[Preparation of a novel activated carbon coating fiber for solid phase micro-extraction and its application for halocarbon compound analysis in water].

PubMed

Wang, Shutao; Wang, Yan; You, Hong; Liang, Zhihua

2004-09-01

A novel activated carbon coating fiber used for solid phase micro-extraction (SPME) was prepared using activated carbon powder and silica resin adhesive. The extraction properties of the novel activated carbon coating fiber were investigated. The results indicate that this coating fiber has high concentration ability, with enrichment factors for chloroform, carbon tetrachloride, trichloroethylene and tetrachloroethylene in the range of 13.8 to 18.7. The fiber is stable at temperature as high as 290 degrees C and it can be used for over 140 times at 250 degrees C. The activated carbon coating fiber was then applied to the analysis of the four halocarbon compounds mentioned above. A linear correlation with correlation coefficients between 0.995 2 and 0.999 4 and the detection limits between 0.008 and 0.05 microg/L were observed. The method was also applied to a real water sample analysis and the recoveries of these halocarbon compounds were from 95.5% to 104.6%.

Classifying organic materials by oxygen-to-carbon elemental ratio to predict the activation regime of cloud condensation nuclei (CCN)

NASA Astrophysics Data System (ADS)

Kuwata, M.; Shao, W.; Lebouteiller, R.; Martin, S. T.

2012-12-01

The governing highly soluble, slightly soluble, or insoluble activation regime of organic compounds as cloud condensation nuclei (CCN) was examined as a function of oxygen-to-carbon elemental ratio (O : C). New data were collected for adipic, pimelic, suberic, azelaic and pinonic acids. Secondary organic materials (SOMs) produced by α-pinene ozonolysis and isoprene photo-oxidation were also included in the analysis. The saturation concentrations C of the organic compounds in aqueous solutions served as the key parameter for delineating regimes of CCN activation, and the values of C were tightly correlated to the O : C ratios. The highly soluble, slightly soluble, and insoluble regimes of CCN activation were found to correspond to ranges of [O : C] > 0.6, 0.2 < [O : C] < 0.6, and [O : C] < 0.2, respectively. These classifications were evaluated against CCN activation data of isoprene-derived SOM (O : C = 0.69-0.72) and α-pinene-derived SOM (O : C = 0.38-0.48). Isoprene-derived SOM had highly soluble activation behavior, consistent with its high O : C ratio. For α-pinene-derived SOM, although CCN activation can be modeled as a highly soluble mechanism, this behavior was not predicted by the O : C ratio, for which a slightly soluble mechanism was anticipated. Complexity in chemical composition, resulting in continuous water uptake and the absence of a deliquescence transition that can thermodynamically limit CCN activation, might explain the differences of α-pinene-derived SOM compared to the behavior of pure organic compounds. The present results suggest that atmospheric particles dominated by hydrocarbon-like organic components do not activate (i.e. insoluble regime) whereas those dominated by oxygenated organic components activate (i.e. highly soluble regime).

Classifying organic materials by oxygen-to-carbon elemental ratio to predict the activation regime of Cloud Condensation Nuclei (CCN)

NASA Astrophysics Data System (ADS)

Kuwata, M.; Shao, W.; Lebouteiller, R.; Martin, S. T.

2013-05-01

The governing highly soluble, slightly soluble, or insoluble activation regime of organic compounds as cloud condensation nuclei (CCN) was examined as a function of oxygen-to-carbon elemental ratio (O : C). New data were collected for adipic, pimelic, suberic, azelaic, and pinonic acids. Secondary organic materials (SOMs) produced by α-pinene ozonolysis and isoprene photo-oxidation were also included in the analysis. The saturation concentrations C of the organic compounds in aqueous solutions served as the key parameter for delineating regimes of CCN activation, and the values of C were tightly correlated to the O : C ratios. The highly soluble, slightly soluble, and insoluble regimes of CCN activation were found to correspond to ranges of [O : C] > 0.6, 0.2 < [O : C] < 0.6, and [O : C] < 0.2, respectively. These classifications were evaluated against CCN activation data of isoprene-derived SOM (O : C = 0.69-0.72) and α-pinene-derived SOM (O : C = 0.38-0.48). Isoprene-derived SOM had highly soluble activation behavior, consistent with its high O : C ratio. For α-pinene-derived SOM, although CCN activation can be modeled as a highly soluble mechanism, this behavior was not predicted by the O : C ratio, for which a slightly soluble mechanism was anticipated. Complexity in chemical composition, resulting in continuous water uptake and the absence of a deliquescence transition that can thermodynamically limit CCN activation, might explain the difference in the behavior of α-pinene-derived SOM compared to that of pure organic compounds. The present results suggest that atmospheric particles dominated by hydrocarbon-like organic components do not activate (i.e., insoluble regime) whereas those dominated by oxygenated organic components activate (i.e., highly soluble regime) for typical atmospheric cloud life cycles.

Antitumor Agents. 272. Structure–Activity Relationships and In Vivo Selective Anti-Breast Cancer Activity of Novel Neo-tanshinlactone Analogs

PubMed Central

Dong, Yizhou; Shi, Qian; Pai, Huei-Chen; Peng, Chieh-Yu; Pan, Shiow-Lin; Teng, Che-Ming; Nakagawa-Goto, Kyoko; Yu, Donglei; Liu, Yi-Nan; Wu, Pei-Chi; Bastow, Kenneth F.; Morris-Natschke, Susan L.; Brossi, Arnold; Lang, Jing-Yu; Hsu, Jennifer L.; Hung, Mien-Chie; Lee, Eva Y.-H. P.; Lee, Kuo-Hsiung

2010-01-01

Neo-tanshinlactone (1) and its previously reported analogs, such as 2, are potent and selective in vitro anti-breast cancer agents. The synthetic pathway to 2 was optimized from seven to five steps, with a better overall yield. Structure–activity relationships studies on these compounds revealed some key molecular determinants for this family of anti-breast agents. Several derivatives (19-21 and 24) exerted potent and selective anti-breast cancer activity with IC50 values of 0.3, 0.2, 0.1 and 0.1 μg/mL, respectively, against the ZR-75-1 cell lines. Compound 24 was two- to three-fold more potent than 1 against SK-BR-3 and ZR-75-1. Importantly, 21 exhibited high selectivity; it was 23 times more active against ZR-75-1 than MCF-7. Compound 20 had an approximately 12-fold ratio of SK-BR-3/MCF-7 selectivity. In addition, analog 2 showed potent activity against a ZR-75-1 xenograft model, but not PC-3 and MDA-MB-231 xenografts, as well as high selectivity against breast cancer cell line compared with normal breast tissue-derived cell lines. Further development of lead compounds 19-21 and 24 as clinical trial candidates is warranted. PMID:20148565

Variation of antioxidant activity and the levels of bioactive compounds in lipophilic and hydrophilic extracts from hot pepper (Capsicum spp.) cultivars.

PubMed

Bae, Haejin; Jayaprakasha, G K; Jifon, John; Patil, Bhimanagouda S

2012-10-15

Peppers (Capsicum spp.) are a rich source of diverse bioactive compounds with potential health-promoting properties. This study investigated the extraction efficiency of five solvents on antioxidant activities from cayenne (CA408 and Mesilla), jalapeño (Ixtapa) and serrano (Tuxtlas) pepper cultivars. Freeze-dried peppers were extracted using a Soxhlet extractor with five solvents: hexane, ethyl acetate, acetone, methanol, and methanol:water (80:20). The levels of specific bioactive compounds (phenolics, capsaicinoids, carotenoids and flavonoids) were determined by HPLC and antioxidant activities were assayed by three methods. For all pepper cultivars tested, hexane extracts had the highest levels of capsaicinoids and carotenoids, but methanol extracts had the maximum levels of flavonoids. Hexane extracts showed higher 2,2-diphenyl-1-pricrylhydrozyl (DPPH) radical-scavenging activity and higher reducing power, and acetone extracts (from Mesilla pepper) had a high reducing power. All pepper extracts, except hexane, were effective in preventing deoxyribose degradation, and the inhibition was increased by high concentrations of extracts. The results of the present study indicated that, among the different measures of antioxidant activity, DPPH radical-scavenging activity was strongly correlated with total bioactive compounds (capsaicinoids, carotenoids, flavonoids and total phenolics) in pepper cultivars. Copyright © 2012 Elsevier Ltd. All rights reserved.

Luminescent macrocyclic lanthanide complexes

DOEpatents

Raymond, Kenneth N; Corneillie, Todd M; Xu, Jide

2014-05-20

The present invention provides a novel class of macrocyclic compounds as well as complexes formed between a metal (e.g., lanthanide) ion and the compounds of the invention. Preferred complexes exhibit high stability as well as high quantum yields of lanthanide ion luminescence in aqueous media without the need for secondary activating agents. Preferred compounds incorporate hydroxy-isophthalamide moieties within their macrocyclic structure and are characterized by surprisingly low, non-specific binding to a variety of polypeptides such as antibodies and proteins as well as high kinetic stability. These characteristics distinguish them from known, open-structured ligands.

Gemini ester quat surfactants and their biological activity.

PubMed

Łuczyński, Jacek; Frąckowiak, Renata; Włoch, Aleksandra; Kleszczyńska, Halina; Witek, Stanisław

2013-03-01

Cationic gemini surfactants are an important class of surface-active compounds that exhibit much higher surface activity than their monomeric counterparts. This type of compound architecture lends itself to the compound being easily adsorbed at interfaces and interacting with the cellular membranes of microorganisms. Conventional cationic surfactants have high chemical stability but poor chemical and biological degradability. One of the main approaches to the design of readily biodegradable and environmentally friendly surfactants involves inserting a bond with limited stability into the surfactant molecule to give a cleavable surfactant. The best-known example of such a compound is the family of ester quats, which are cationic surfactants with a labile ester bond inserted into the molecule. As part of this study, a series of gemini ester quat surfactants were synthesized and assayed for their biological activity. Their hemolytic activity and changes in the fluidity and packing order of the lipid polar heads were used as the measures of their biological activity. A clear correlation between the hemolytic activity of the tested compounds and their alkyl chain length was established. It was found that the compounds with a long hydrocarbon chain showed higher activity. Moreover, the compounds with greater spacing between their alkyl chains were more active. This proves that they incorporate more easily into the lipid bilayer of the erythrocyte membrane and affect its properties to a greater extent. A better understanding of the process of cell lysis by surfactants and of their biological activity may assist in developing surfactants with enhanced selectivity and in widening their range of application.

Inhibition of the pore-forming protein perforin by a series of aryl-substituted isobenzofuran-1(3H)-ones.

PubMed

Spicer, Julie A; Huttunen, Kristiina M; Miller, Christian K; Denny, William A; Ciccone, Annette; Browne, Kylie A; Trapani, Joseph A

2012-02-01

An aryl-substituted isobenzofuran-1(3H)-one lead compound was identified from a high throughput screen designed to find inhibitors of the lymphocyte pore-forming protein perforin. A series of analogs were then designed and prepared, exploring structure-activity relationships through variation of 2-thioxoimidazolidin-4-one and furan subunits on an isobenzofuranone core. The ability of the resulting compounds to inhibit the lytic activity of both isolated perforin protein and perforin delivered in situ by intact KHYG-1 natural killer effector cells was determined. Several compounds showed excellent activity at concentrations that were non-toxic to the killer cells. This series represents a significant improvement on previous classes of compounds, being substantially more potent and largely retaining activity in the presence of serum. Copyright © 2011 Elsevier Ltd. All rights reserved.

Discovery of an Orally Bioavailable Gonadotropin-Releasing Hormone Receptor Antagonist.

PubMed

Kim, Seon-Mi; Lee, Minhee; Lee, So Young; Park, Euisun; Lee, Soo-Min; Kim, Eun Jeong; Han, Min Young; Yoo, Taekyung; Ann, Jihyae; Yoon, Suyoung; Lee, Jiyoun; Lee, Jeewoo

2016-10-13

We developed a compound library for orally available gonadotropin-releasing hormone (GnRH) receptor antagonists that were based on a uracil scaffold. On the basis of in vitro activity and CYP inhibition profile, we selected 18a (SKI2496) for further in vivo studies. Compound 18a exhibited more selective antagonistic activity toward the human GnRH receptors over the GnRHRs in monkeys and rats, and this compound also showed inhibitory effects on GnRH-mediated signaling pathways. Pharmacokinetic and pharmacodynamic evaluations of 18a revealed improved bioavailability and superior gonadotropic suppression activity compared with Elagolix, the most clinically advanced compound. Considering that 18a exhibited highly potent and selective antagonistic activity toward the hGnRHRs along with favorable pharmacokinetic profiles, we believe that 18a may represent a promising candidate for an orally available hormonal therapy.

Phenolic compounds from the leaf extract of artichoke (Cynara scolymus L.) and their antimicrobial activities.

PubMed

Zhu, Xianfeng; Zhang, Hongxun; Lo, Raymond

2004-12-01

A preliminary antimicrobial disk assay of chloroform, ethyl acetate, and n-butanol extracts of artichoke (Cynara scolymus L.) leaf extracts showed that the n-butanol fraction exhibited the most significant antimicrobial activities against seven bacteria species, four yeasts, and four molds. Eight phenolic compounds were isolated from the n-butanol soluble fraction of artichoke leaf extracts. On the basis of high-performance liquid chromatography/electrospray ionization mass spectrometry, tandem mass spectrometry, and nuclear magnetic resonance techniques, the structures of the isolated compounds were determined as the four caffeoylquinic acid derivatives, chlorogenic acid (1), cynarin (2), 3,5-di-O-caffeoylquinic acid (3), and 4,5-di-O-caffeoylquinic acid (4), and the four flavonoids, luteolin-7-rutinoside (5), cynaroside (6), apigenin-7-rutinoside (7), and apigenin-7-O-beta-D-glucopyranoside (8), respectively. The isolated compounds were examined for their antimicrobial activities on the above microorganisms, indicating that all eight phenolic compounds showed activity against most of the tested organisms. Among them, chlorogenic acid, cynarin, luteolin-7-rutinoside, and cynaroside exhibited a relatively higher activity than other compounds; in addition, they were more effective against fungi than bacteria. The minimum inhibitory concentrations of these compounds were between 50 and 200 microg/mL.

Analysis of Nonpoint-Source Ground-Water Contamination in Relation to Land Use: Assessment of Nonpoint-Source Contamination in Central Florida

USGS Publications Warehouse

German, Edward R.

1996-01-01

In central Florida, activities that might affect the quality of ground water include disposal of stormwater through drainage wells, citrus cultivation, and mining and processing of phosphate ore. Possible effects of these and other land-use activities include high concentrations of nitrogen compounds and the pesticide bromacil in the citrus area, and high concentrations of most of the major-dissolved constituents and some organic compounds in the mining area.

Synthesis of the iron phthalocyaninate radical cation μ-nitrido dimer and its interaction with hydrogen peroxide

NASA Astrophysics Data System (ADS)

Grishina, E. S.; Makarova, A. S.; Kudrik, E. V.; Makarov, S. V.; Koifman, O. I.

2016-03-01

The iron phthalocyaninate μ-nitrido dimer radical cation, as well as the μ-nitrido dimer complexes of iron phthalocyaninate, was found to have high catalytic activity in the oxidation of organic compounds. It was concluded that this compound is of interest as a model of active intermediates—catalase and oxidase enzymes.

New insights into highly potent tyrosinase inhibitors based on 3-heteroarylcoumarins: Anti-melanogenesis and antioxidant activities, and computational molecular modeling studies.

PubMed

Pintus, Francesca; Matos, Maria J; Vilar, Santiago; Hripcsak, George; Varela, Carla; Uriarte, Eugenio; Santana, Lourdes; Borges, Fernanda; Medda, Rosaria; Di Petrillo, Amalia; Era, Benedetta; Fais, Antonella

2017-03-01

Melanogenesis is a physiological pathway for the formation of melanin. Tyrosinase catalyzes the first step of this process and down-regulation of its activity is responsible for the inhibition of melanogenesis. The search for molecules capable of controlling hyperpigmentation is a trend topic in health and cosmetics. A series of heteroarylcoumarins have been synthesized and evaluated. Compounds 4 and 8 exhibited higher tyrosinase inhibitory activities (IC 50 =0.15 and 0.38μM, respectively), than the reference compound, kojic acid (IC 50 =17.9μM). Compound 4 acts as competitive, while compound 8 as uncompetitive inhibitor of mushroom tyrosinase. Furthermore, compounds 2 and 8 inhibited tyrosinase activity and melanin production in B16F10 cells. In addition, compounds 2-4 and 8 proved to have an interesting antioxidant profile in both ABTS and DPPH radicals scavenging assays. Docking experiments were carried out in order to study the interactions between these heteroarylcoumarins and mushroom tyrosinase. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design, synthesis, molecular docking, anti-Proteus mirabilis and urease inhibition of new fluoroquinolone carboxylic acid derivatives.

PubMed

Abdullah, Mohammed A A; Abuo-Rahma, Gamal El-Din A A; Abdelhafez, El-Shimaa M N; Hassan, Heba A; Abd El-Baky, Rehab M

2017-02-01

New hydroxamic acid, hydrazide and amide derivatives of ciprofloxacin in addition to their analogues of levofloxacin were prepared and identified by different spectroscopic techniques. Some of the prepared compounds revealed good activity against the urease splitting bacteria, Proteus mirabilis. The urease inhibitory activity was investigated using indophenol method. Most of the tested compounds showed better activity than the reference acetohydroxamic acid (AHA). The ciprofloxacin hydrazide derivative 3a and levofloxacin hydroxamic acid 7 experienced the highest activity (IC 50 =1.22μM and 2.20μM, respectively). Molecular docking study revealed high spontaneous binding ability of the tested compounds to the active site of urease. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of Titratable Acids, Phenolic Compounds, and Antioxidant Activities of Wines Made from Eight Mississippi-Grown Muscadine Varieties during Fermentation

USDA-ARS?s Scientific Manuscript database

Muscadine grape (vitis rotundifolia) Michx.) and its wine products are becoming more acceptable due to potential health benefits associated with high concentrations of phenolic compounds. In this research, wines made from eight high-yielding muscadine grape varieties grown in Mississippi were compa...

The antibacterial activity of compounds isolated from oakmoss against Legionella pneumophila and other Legionella spp.

PubMed

Nomura, Harue; Isshiki, Yasunori; Sakuda, Keisuke; Sakuma, Katsuya; Kondo, Seiichi

2012-01-01

Oakmoss is a natural fragrance ingredient exhibiting highly specific, potent antibacterial activity against Legionella pneumophila, a causative agent of severe water-bone pneumonia. In the present study, the antibacterial activity of individual compounds isolated from oakmoss was investigated against L. pneumophila and other Legionella spp. A total of 18 known compounds and two minor novel compounds (i.e., 3-methoxy-5-methylphenyl-2,4-dihydroxy-6-methylbenzoate (compound 9) and 8-(2,4-dihydroxy-6-(2-oxoheptyl)-phenoxy)-6-hydroxy-3-pentyl-1H-isochromen-1-one (compound 20)) were purified from oakmoss. The minimum inhibitory concentrations (MICs) against clinical and environmental isolates of L. pneumophila, L. bozemanii, L. micdadei, L. longbeachae, and L. dumoffii for 11 of the 20 compounds were less than 100 µg/mL (range 0.8-64.0 µg/mL). Novel compounds 9 and 20 exhibited potent antibacterial activity against L. pneumophila strains (MIC ranges of 1.3-8.0 µg/mL and 3.3-13.3 µg/mL, respectively) and also against four other Legionella species (MIC ranges of 0.8-8.0 µg/mL and 3.3-21.3 µg/mL, respectively). Time-kill assays indicated that compounds 9 and 20 kill bacteria at a concentration equivalent to 2×MIC after 1 h and 6 h co-incubations, respectively. While oakmoss and the purified components exhibited antibacterial activity against Legionella spp., they were not active against other Gram-negative and -positive bacteria such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus.

Shock-activated reaction synthesis and high pressure response of titanium-based ternary carbide and nitride ceramics

NASA Astrophysics Data System (ADS)

Jordan, Jennifer Lynn

The objectives of this study were to (a) investigate the effect of shock activation of precursor powders for solid-state reaction synthesis of Ti-based ternary ceramics and (b) to determine the high pressure phase stability and Hugoniot properties of Ti3SiC2. Dynamically densified compacts of Ti, SiC, and graphite precursor powders and Ti and AlN precursor powders were used to study the shock-activated formation of Ti 3SiC2 and Ti2AlN ternary compounds, respectively, which are considered to be novel ceramics having high stiffness but low hardness. Gas gun and explosive loading techniques were used to obtain a range of loading conditions resulting in densification and activation. Measurements of fraction reacted as a function of time and temperature and activation energies obtained from DTA experiments were used to determine the degree of activation caused by shock compression and its subsequent effect on the reaction mechanisms and kinetics. In both systems, shock activation led to an accelerated rate of reaction at temperatures less than 1600°C and, above that temperature, it promoted the formation of almost 100% of the ternary compound. A kinetics-based mathematical model based on mass and thermal transport was developed to predict the effect of shock activation and reaction synthesis conditions that ensure formation of the ternary compounds. Model predictions revealed a transition temperature above which the reaction is taken over by the "run-away" combustion-type mode. The high pressure phase stability of pre-alloyed Ti 3SiC2 compound was investigated by performing Hugoniot shock and particle velocity measurements using the facilities at the National Institute for Materials Science (Tsukuba, Japan). Experiments performed at pressures of 95--120 GPa showed that the compressibility of Ti3SiC 2 at these pressures deviates from the previously reported compressibility of the material under static high pressure loading. The deviation in compressibility behavior is indicative of the transformation of the Ti3 SiC2 ceramic to a high pressure, high density phase.

Formation, characterization, aggregation, fluorescence and antioxidant properties of novel tetrasubstituted metal-free and metallophthalocyanines bearing (4-(methylthio)phenoxy) moieties

NASA Astrophysics Data System (ADS)

Yıldırım, Nurdan; Bilgiçli, Ahmet T.; Alici, Esma Hande; Arabacı, Gulnur; Yarasir, M. Nilüfer

2017-09-01

The synthesis and characterization of peripherally tetra 4-(methylthio)phenoxy substituted metal-free(2), Zn(II) (3) and Co(II) (4) phthalocyanine derivatives were reported. These newly synthesized phthalocyanine derivatives showed the enhanced solubility in organic solvents and they were characterized by a combination of elemental analysis, FTIR, 1H NMR, 13C NMR, UV-vis and MALDI-TOF/MS spectral data. Their aggregation properties were investigated in THF by UV-vis and fluorescence. These metal-free and metallophthalocyanine compounds were also evaluated for their total antioxidant abilities by using three different antioxidant methods such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, ferrous ion chelating and reducing power activity. All tested compounds showed radical scavenging activity. The highest radical scavenging activity was found from cobalt phthalocyanine (4) compound respectively. IC50 values of the compounds and standards (BHT and Trolox) were also determined. The results showed that the compound 4 had the highest antioxidant activity among all tested compounds including standards. The tested phthalocyanine compounds had ferrous ion chelating activity. In addition, they showed very high reducing power. All tested compounds had higher reducing power than the standards such as ascorbic acid and BHT. The present study shows that the synthesized tetra phthalocyanine [M: 2H(2), Zn(II)(3), Co(II)(4)] with four peripheral 4-(methylthio) phenoxy compounds have the effective antioxidant properties that can be used as antioxidant agents.

Screening Active Compounds from Garcinia Species Native to China Reveals Novel Compounds Targeting the STAT/JAK Signaling Pathway

PubMed Central

Xu, Linfeng; Lao, Yuanzhi; Zhao, Yanhui; Qin, Jian; Fu, Wenwei; Zhang, Yingjia; Xu, Hongxi

2015-01-01

Natural compounds from medicinal plants are important resources for drug development. In a panel of human tumor cells, we screened a library of the natural products from Garcinia species which have anticancer potential to identify new potential therapeutic leads and discovered that caged xanthones were highly effective at suppressing multiple cancer cell lines. Their anticancer activities mainly depended on apoptosis pathways. For compounds in sensitive cancer line, their mechanisms of mode of action were evaluated. 33-Hydroxyepigambogic acid and 35-hydroxyepigambogic acid exhibited about 1 μM IC50 values against JAK2/JAK3 kinases and less than 1 μM IC50 values against NCI-H1650 cell which autocrined IL-6. Thus these two compounds provided a new antitumor molecular scaffold. Our report describes 33-hydroxyepigambogic acid and 35-hydroxyepigambogic acid that inhibited NCI-H1650 cell growth by suppressing constitutive STAT3 activation via direct inhibition of JAK kinase activity. PMID:26090459

A Genomics-Based Approach Identifies a Thioviridamide-Like Compound with Selective Anticancer Activity.

PubMed

Frattaruolo, Luca; Lacret, Rodney; Cappello, Anna Rita; Truman, Andrew W

2017-11-17

Thioviridamide is a structurally novel ribosomally synthesized and post-translational modified peptide (RiPP) produced by Streptomyces olivoviridis NA005001. It is characterized by a structure that features a series of thioamide groups and possesses potent antiproliferative activity in cancer cell lines. Its unusual structure allied to its promise as an anticancer compound led us to investigate the diversity of thioviridamide-like pathways across sequenced bacterial genomes. We have isolated and characterized three diverse members of this family of natural products. This characterization is supported by transformation-associated recombination cloning and heterologous expression of one of these compounds, thiostreptamide S4. Our work provides an insight into the diversity of this rare class of compound and indicates that the unusual N-terminus of thioviridamide is not introduced biosynthetically but is instead introduced during acetone extraction. A detailed analysis of the biological activity of one of the newly discovered compounds, thioalbamide, indicates that it is highly cytotoxic to cancer cells, while exhibiting significantly less activity toward a noncancerous epithelial cell line.

Benzimidazobenzothiazole-based highly-efficient thermally activated delayed fluorescence emitters for organic light-emitting diodes: A quantum-chemical TD-DFT study

NASA Astrophysics Data System (ADS)

Zhu, Qiuling; Wen, Keke; Feng, Songyan; Guo, Xugeng; Zhang, Jinglai

2018-03-01

Based upon two thermally activated delayed fluorescence (TADF) emitters 1 and 2, compounds 3-6 have been designed by replacing the carbazol group with the bis(4-biphenyl)amine one (3 and 4) and introducing the electron-withdrawing CF3 group into the acceptor unit of 3 and 4 (5 and 6). It is found that the present calculations predict comparable but relatively large energy differences (approximate 0.5 eV) between the lowest singlet S1 and triplet T1 states (Δ EST) for the six targeted compounds. In order to explain the highly-efficient TADF behavior observed in compounds 1 and 2, the"triplet reservoir" mechanism has been proposed. In addition, the fluorescence rates of all six compounds are very large, in 107-108 orders of magnitude. According to the present calculations, it is a reasonable assumption that the newly designed compounds 3-6 could be considered as the potential TADF emitters, which needs to be further verified by experimental techniques.

1,2-Benzisoselenazol-3(2H)-one Derivatives As a New Class of Bacterial Urease Inhibitors.

PubMed

Macegoniuk, Katarzyna; Grela, Ewa; Palus, Jerzy; Rudzińska-Szostak, Ewa; Grabowiecka, Agnieszka; Biernat, Monika; Berlicki, Łukasz

2016-09-08

Urease inhibitors are considered promising compounds for the treatment of ureolytic bacterial infections, particularly infections resulting from Helicobacter pylori in the gastric tract. Herein, we present the synthesis and the inhibitory activity of novel and highly effective organoselenium compounds as inhibitors of Sporosarcina pasteurii and Helicobacter pylori ureases. These studied compounds represent a class of competitive reversible urease inhibitors. The most active compound, 2-phenyl-1,2-benzisoselenazol-3(2H)-one (ebselen), displayed Ki values equal to 2.11 and 226 nM against S. pasteurii and H. pylori enzymes, respectively, indicating ebselen as one of the most potent low-molecular-weight inhibitors of bacterial ureases reported to date. Most of these molecules penetrated through the cell membrane of the Gram-negative bacteria Escherichia coli (pGEM::ureOP) in vitro. Furthermore, whole-cell studies on the H. pylori J99 reference strain confirmed the high efficiency of the examined organoselenium compounds as urease inhibitors against pathogenic bacteria.

Antimycobacterial and antimalarial activities of endophytic fungi associated with the ancient and narrowly endemic neotropical plant Vellozia gigantea from Brazil.

PubMed

Ferreira, Mariana C; Cantrell, Charles L; Wedge, David E; Gonçalves, Vívian N; Jacob, Melissa R; Khan, Shabana; Rosa, Carlos A; Rosa, Luiz H

2017-10-01

Endophytic fungi, present mainly in the Ascomycota and Basidiomycota phyla, are associated with different plants and represent important producers of bioactive natural products. Brazil has a rich biodiversity of plant species, including those reported as being endemic. Among the endemic Brazilian plant species, Vellozia gigantea (Velloziaceae) is threatened by extinction and is a promising target to recover endophytic fungi. The present study focused on bioprospecting of bioactive compounds of the endophytic fungi associated with V. gigantea, an endemic, ancient, and endangered plant species that occurs only in the rupestrian grasslands of Brazil. The capability of 285 fungal isolates to produce antimicrobial and antimalarial activities was examined. Fungi were grown at solid-state fermentation to recover their crude extracts in dichloromethane. Bioactive extracts were analysed by chromatographic fractionation and NMR and displayed compounds with antimicrobial, antimycobacterial, and antimalarial activities. Five fungi produced antimicrobial and antimalarial compounds. Extracts of Diaporthe miriciae showed antifungal, antibacterial, and antimalarial activities; Trichoderma effusum displayed selective antibacterial activity against methicillin-resistant Staphylococcus aureus and Mycobacterium intracellulare; and three Penicillium species showed antibacterial activity. D. miriciae extract contained highly functionalised secondary metabolites, yielding the compound epoxycytochalasin H with high antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum, with an IC50 approximately 3.5-fold lower than that with chloroquine. Our results indicate that V. gigantea may represent a microhabitat repository hotspot of potential fungi producers of bioactive compounds and suggest that endophytic fungal communities might be an important biological component contributing to the fitness of the plants living in the rupestrian grassland.

Phaeophleospora vochysiae Savi & Glienke sp. nov. Isolated from Vochysia divergens Found in the Pantanal, Brazil, Produces Bioactive Secondary Metabolites.

PubMed

Savi, Daiani C; Shaaban, Khaled A; Gos, Francielly Maria Wilke Ramos; Ponomareva, Larissa V; Thorson, Jon S; Glienke, Chirlei; Rohr, Jürgen

2018-02-15

Microorganisms associated with plants are highly diverse and can produce a large number of secondary metabolites, with antimicrobial, anti-parasitic and cytotoxic activities. We are particularly interested in exploring endophytes from medicinal plants found in the Pantanal, a unique and widely unexplored wetland in Brazil. In a bio-prospecting study, strains LGMF1213 and LGMF1215 were isolated as endophytes from Vochysia divergens, and by morphological and molecular phylogenetic analyses were characterized as Phaeophleospora vochysiae sp. nov. The chemical assessment of this species reveals three major compounds with high biological activity, cercoscosporin (1), isocercosporin (2) and the new compound 3-(sec-butyl)-6-ethyl-4,5-dihydroxy-2-methoxy-6-methylcyclohex-2-enone (3). Besides the isolation of P. vochysiae as endophyte, the production of cercosporin compounds suggest that under specific conditions this species causes leaf spots, and may turn into a pathogen, since leaf spots are commonly caused by species of Cercospora that produce related compounds. In addition, the new compound 3-(sec-butyl)-6-ethyl-4,5-dihydroxy-2-methoxy-6-methylcyclohex-2-enone showed considerable antimicrobial activity and low cytotoxicity, which needs further exploration.

Phloroglucinol derivatives from Hypericum species trigger mitochondrial dysfunction in Leishmania amazonensis.

PubMed

Dagnino, Ana Paula Aquistapase; Mesquita, Camila Saporiti; Dorneles, Gilson Pires; Teixeira, Vivian de Oliveira Nunes; de Barros, Francisco Maikon Corrêa; Vidal Ccana-Ccapatinta, Gari; Fonseca, Simone Gonçalves; Monteiro, Marta Chagas; Júnior, Luiz Carlos Rodrigues; Peres, Alessandra; von Poser, Gilsane Lino; Romão, Pedro Roosevelt Torres

2018-02-27

Bioactive molecules isolated from plants are promising sources for the development of new therapies against leishmaniasis. We investigated the leishmanicidal activity of cariphenone A (1), isouliginosin B (2) and uliginosin B (3) isolated from Hypericum species. Promastigotes and amastigotes of Leishmania amazonensis were incubated with compounds 1-3 at concentrations 1-100 µ m for 48 h. The anti-promastigote effect of compounds was also tested in combinations. The cytotoxicity against macrophages and human erythrocytes were determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method and hemolysis assay, respectively. The compounds 1-3 showed high leishmanicidal activity against promastigotes, IC50 values of 10.5, 17.5 and 11.3 µ m, respectively. Synergistic interactions were found to the associations of compounds 1 and 2 [Σ fractional inhibitory concentration (FIC) = 0.41], and 2 and 3 (ΣFIC = 0.28) on promastigotes. All Hypericum compounds induced mitochondrial hyperpolarization and reactive oxygen species production in promastigotes. The compounds showed low cytotoxicity toward mammalian cells, high selectivity index and killed intracellular amastigotes probably mediated by oxidative stress. These results indicate that these compounds are promising candidates for the development of drugs against leishmaniasis.

3D-QSAR analysis of MCD inhibitors by CoMFA and CoMSIA.

PubMed

Pourbasheer, Eslam; Aalizadeh, Reza; Ebadi, Amin; Ganjali, Mohammad Reza

2015-01-01

Three-dimensional quantitative structure-activity relationship was developed for the series of compounds as malonyl-CoA decarboxylase antagonists (MCD) using the CoMFA and CoMSIA methods. The statistical parameters for CoMFA (q(2)=0.558, r(2)=0.841) and CoMSIA (q(2)= 0.615, r(2) = 0.870) models were derived based on 38 compounds as training set in the basis of the selected alignment. The external predictive abilities of the built models were evaluated by using the test set of nine compounds. From obtained results, the CoMSIA method was found to have highly predictive capability in comparison with CoMFA method. Based on the given results by CoMSIA and CoMFA contour maps, some features that can enhance the activity of compounds as MCD antagonists were introduced and used to design new compounds with better inhibition activity.

Synthesis and structure-activity relationship of di-(3, 8-diazabicyclo[3.2.1]octane) diquaternary ammonium salts as unique analgesics.

PubMed

Liu, Hong; Cheng, Tie-Ming; Zhang, Hong-Mei; Li, Run-Tao

2003-11-01

Based on the structure characteristics of the lead compounds, 1, 1' octanedioyl-4, 4'-dimethyl-4, 4'-dibenzyl dipiperazinium dibromide (2) and 3, 8-disubstituted-3, 8-diazabicyclo [3.2.1]octanes (DBO), di-(3, 8-diazabicyclo [3.2.1]octane) diquaternary ammonium salts 3 a-c were designed and synthesized through a highly practical procedure. Target compounds 3 a-c and the hydrochloride salts of their precursors 10 a-c were evaluated for their in vivo analgesic and sedative activities. Interestingly, the introduction of an endoethylenic bridge in the piperazine of lead compound 2 causes loss of the analgesic activity and increases the toxicity dramatically. This result shows that the flexible conformation of piperazine in compound 2 is favorable for interaction with the receptor, and the quaternization of compounds 10 a-c is the main reason for the toxicity increase.

Polyphenols in strawberry (Fragaria × ananassa) leaves induced by plant activators.

PubMed

Kårlund, Anna; Salminen, Juha-Pekka; Koskinen, Piia; Ahern, Jeffrey R; Karonen, Maarit; Tiilikkala, Kari; Karjalainen, Reijo O

2014-05-21

Strawberry leaves contain high amounts of diverse phenolic compounds potentially possessing defensive activities against microbial pathogens and beneficial properties for human health. In this work, young strawberry plants were treated with two plant activators, S-methylbenzo-1,2,3-thaidiazole-7-carbothiate (BTH) and birch wood distillate. Phenolic compounds from activator-treated and control leaves were subjected to quantitative analyses by HPLC-DAD, HPLC-ESI-MS, and microQTOF ESI-MS. Thirty-two different phenolic compounds were detected and characterized, and 21 different ellagitannins constituted the largest group of compounds in the strawberry leaves (37.88-45.82 mg/g dry weight, 47.0-54.3% of total phenolics). Treatment with BTH resulted in higher levels of individual ellagitannins, whereas treatment with birch wood distillate strongly increased the levels of chlorogenic acid in strawberry leaves compared with the control. The results suggest that different plant activators may be useful tools for the activation of different branches in the phenylpropanoid biosynthesis in strawberry.

Antioxidant and Anticholinesterase Activities of Some Dialkylamino Substituted 3-Hydroxyflavone Derivatives.

PubMed

Culhaoglu, Burcu; Capan, Asli; Boga, Mehmet; Ozturk, Mehmet; Ozturk, Turan; Topcu, Gulacti

2017-01-01

Flavones, are a class of naturally occuring polyphenolic compounds which have 2-phenylchromen-4-one structure. Various studies showed that flavones have several pharmacological activities such as antioxidant, anti-inflammatory, antimicrobial, cytotoxic, antitumour and antiallergic. In the present study, 3-hydroxyflavones also called flavonols, posessing 4'-dialkylamino moiety were synthesized, and their antioxidant and anticholinesterase activities were investigated by comparison with unmodified 3-hydroxflavone. For investigation of antioxidant potential, radical scavenging assays (DPPH•, ABTS+_, O2.-) were used along with CUPRAC and lipid peroxidation inhibitory assays, as well as anticholinesterase activity by Ellman method. The best results were obtained for 4'-N,N-dimethyl flavonol (1) in both antioxidant and anticholinesterase activity tests, possibly due to its least steric hinderance effect. It exhibited remarkable DPPH free radical scavenging activity (2.43±0,09 μg/mL) competing with a standard compound quercetin (2.10±0,10 μg/mL). Moreover, the other tested flavonols also showed high antioxidant activities. Compounds 5 and 6 exhibited close IC50 values to those of compound 1. Antioxidant activity test results were found to be well correlated with anticholinesterase activity test results indicating possible role of antioxidant compounds in the treatment of Alzheimer's disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Understanding the Effects of Roasting on Antioxidant Components of Coffee Brews by Coupling On‐line ABTS Assay to High Performance Size Exclusion Chromatography

PubMed Central

Opitz, Sebastian E.W.; Goodman, Bernard A.; Keller, Marco; Smrke, Samo; Wellinger, Marco; Schenker, Stefan

2016-01-01

Abstract Introduction Coffee is a widely consumed beverage containing antioxidant active compounds. During roasting the phytochemical composition of the coffee bean changes dramatically and highly polymeric substances are produced. Besides chlorogenic acids that are already present in green coffee beans, melanoidins show antioxidant capacity as well. Objective To employ post‐column derivatisation by coupling high performance size exclusion chromatography (HPSEC) to an antioxidant assay to investigate the effect of roasting on the properties of antioxidant active compounds in coffee brews. Methodology We have investigated the antioxidant capacity of Coffea arabica (Arabica) and C. canephora (Robusta) beans that were roasted over the full spectrum of roast conditions (four roasting speeds to three roast degrees) by comparing the results from HPSEC coupled on‐line to the ABTS assay with those from two batch assays, Folin Ciocalteu (FC) and oxygen radical absorbance capacity (ORAC) assay. Results The antioxidant capacity showed a general decrease towards slower and darker roasted coffee for all three assays, indicative of heat degradation of active compounds. Hence, low molecular weight (LMW) compounds such as chlorogenic acids (CGAs) decreased progressively already from relatively mild roasting conditions. In contrast, high molecular weight (HMW) compounds (e.g. melanoidins) increased from light to dark roast degrees with lowering magnitude towards slower roasting profiles. Conclusion By coupling HPSEC on‐line to the ABTS assay we were able to separately quantify the contribution of HMW and LMW compounds to the total antioxidant capacity, increasing our understanding of the roast process. © 2016 The Authors. Phytochemical Analysis Published by John Wiley & Sons Ltd. PMID:28008674

Understanding the Effects of Roasting on Antioxidant Components of Coffee Brews by Coupling On-line ABTS Assay to High Performance Size Exclusion Chromatography.

PubMed

Opitz, Sebastian E W; Goodman, Bernard A; Keller, Marco; Smrke, Samo; Wellinger, Marco; Schenker, Stefan; Yeretzian, Chahan

2017-03-01

Coffee is a widely consumed beverage containing antioxidant active compounds. During roasting the phytochemical composition of the coffee bean changes dramatically and highly polymeric substances are produced. Besides chlorogenic acids that are already present in green coffee beans, melanoidins show antioxidant capacity as well. To employ post-column derivatisation by coupling high performance size exclusion chromatography (HPSEC) to an antioxidant assay to investigate the effect of roasting on the properties of antioxidant active compounds in coffee brews. We have investigated the antioxidant capacity of Coffea arabica (Arabica) and C. canephora (Robusta) beans that were roasted over the full spectrum of roast conditions (four roasting speeds to three roast degrees) by comparing the results from HPSEC coupled on-line to the ABTS assay with those from two batch assays, Folin Ciocalteu (FC) and oxygen radical absorbance capacity (ORAC) assay. The antioxidant capacity showed a general decrease towards slower and darker roasted coffee for all three assays, indicative of heat degradation of active compounds. Hence, low molecular weight (LMW) compounds such as chlorogenic acids (CGAs) decreased progressively already from relatively mild roasting conditions. In contrast, high molecular weight (HMW) compounds (e.g. melanoidins) increased from light to dark roast degrees with lowering magnitude towards slower roasting profiles. By coupling HPSEC on-line to the ABTS assay we were able to separately quantify the contribution of HMW and LMW compounds to the total antioxidant capacity, increasing our understanding of the roast process. © 2016 The Authors. Phytochemical Analysis Published by John Wiley & Sons Ltd. © 2016 The Authors. Phytochemical Analysis Published by John Wiley & Sons Ltd.

Volatile Compound, Physicochemical, and Antioxidant Properties of Beany Flavor-Removed Soy Protein Isolate Hydrolyzates Obtained from Combined High Temperature Pre-Treatment and Enzymatic Hydrolysis

PubMed Central

Yoo, Sang-Hun; Chang, Yoon Hyuk

2016-01-01

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G′, G″) of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities. PMID:28078256

Volatile Compound, Physicochemical, and Antioxidant Properties of Beany Flavor-Removed Soy Protein Isolate Hydrolyzates Obtained from Combined High Temperature Pre-Treatment and Enzymatic Hydrolysis.

PubMed

Yoo, Sang-Hun; Chang, Yoon Hyuk

2016-12-01

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G', G″) of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities.

Odor-Active Compounds in the Special Flavor Hops Huell Melon and Polaris.

PubMed

Neiens, Silva D; Steinhaus, Martin

2018-02-14

The volatiles isolated from samples of the special flavor hop varieties, Huell Melon and Polaris, and from the aroma hop variety, Hallertau Tradition, by solvent extraction and solvent-assisted flavor evaporation (SAFE) were subjected to a comparative aroma extract dilution analysis (cAEDA), which resulted in 46 odor-active compounds in the flavor dilution (FD) factor range of 16 to 2048. On the basis of high FD factors, myrcene, (3R)-linalool, and 2- and 3-methylbutanoic acid were confirmed as important variety-independent hop odorants. (1R,4S)-Calamenene was identified for the first time as an odor-active compound in hops. Clear differences in the FD factors and their subsequent objectification by stable isotope dilution quantitation suggested that high concentrations of the esters ethyl 2-methylbutanoate, ethyl 2-methylpropanoate, and propyl 2-methylbutanoate cause the characteristic fruity, cantaloupe-like odor note in Huell Melon hops, whereas the fruity and minty odor notes in Polaris are associated with high amounts of 3-methylbutyl acetate and 1,8-cineole.

Design, synthesis, and biological characterization of metabolically stable selective androgen receptor modulators.

PubMed

Marhefka, Craig A; Gao, Wenqing; Chung, Kiwon; Kim, Juhyun; He, Yali; Yin, Donghua; Bohl, Casey; Dalton, James T; Miller, Duane D

2004-02-12

A series of nonsteroidal ligands were synthesized as second-generation agonists for the androgen receptor (AR). These ligands were designed to eliminate metabolic sites identified in one of our first-generation AR agonists, which was inactive in vivo due to its rapid metabolism to inactive constituents. The binding affinity of these compounds was evaluated using AR isolated from rat ventral prostate. These second-generation compounds bound the AR in a high affinity and stereoselective manner, with K(i) values ranging from about 4 to 130 nM. The ability of these ligands to stimulate AR-mediated transcriptional activation was examined in cells transfected with the human AR and a hormone-dependent luciferase reporter gene. Although some compounds were unable to stimulate AR-mediated transcription, several demonstrated activity similar to that of dihydrotestosterone (DHT, an endogenous steroidal ligand for the AR). We also evaluated the in vivo pharmacologic activity of selected compounds in castrated male rats. Three compounds were identified as selective androgen receptor modulators (SARMs), exhibiting significant anabolic activity while having only moderate to minimal androgenic activity in vivo.

Design, Synthesis, and Biological Characterization of Metabolically Stable Selective Androgen Receptor Modulators

PubMed Central

Marhefka, Craig A.; Gao, Wenqing; Chung, Kiwon; Kim, Juhyun; He, Yali; Yin, Donghua; Bohl, Casey; Dalton, James T.; Miller, Duane D.

2007-01-01

A series of nonsteroidal ligands were synthesized as second-generation agonists for the androgen receptor (AR). These ligands were designed to eliminate metabolic sites identified in one of our first-generation AR agonists, which was inactive in vivo due to its rapid metabolism to inactive constituents. The binding affinity of these compounds was evaluated using AR isolated from rat ventral prostate. These second-generation compounds bound the AR in a high affinity and stereoselective manner, with Ki values ranging from about 4 to 130 nM. The ability of these ligands to stimulate AR-mediated transcriptional activation was examined in cells transfected with the human AR and a hormone-dependent luciferase reporter gene. Although some compounds were unable to stimulate AR-mediated transcription, several demonstrated activity similar to that of dihydrotestosterone (DHT, an endogenous steroidal ligand for the AR). We also evaluated the in vivo pharmacologic activity of selected compounds in castrated male rats. Three compounds were identified as selective androgen receptor modulators (SARMs), exhibiting significant anabolic activity while having only moderate to minimal androgenic activity in vivo. PMID:14761201

A High-Throughput Cell-Based Screen Identified a 2-[(E)-2-Phenylvinyl]-8-Quinolinol Core Structure That Activates p53

PubMed Central

Bechill, John; Zhong, Rong; Zhang, Chen; Solomaha, Elena

2016-01-01

p53 function is frequently inhibited in cancer either through mutations or by increased degradation via MDM2 and/or E6AP E3-ubiquitin ligases. Most agents that restore p53 expression act by binding MDM2 or E6AP to prevent p53 degradation. However, fewer compounds directly bind to and activate p53. Here, we identified compounds that shared a core structure that bound p53, caused nuclear localization of p53 and caused cell death. To identify these compounds, we developed a novel cell-based screen to redirect p53 degradation to the Skip-Cullin-F-box (SCF) ubiquitin ligase complex in cells expressing high levels of p53. In a multiplexed assay, we coupled p53 targeted degradation with Rb1 targeted degradation in order to identify compounds that prevented p53 degradation while not inhibiting degradation through the SCF complex or other proteolytic machinery. High-throughput screening identified several leads that shared a common 2-[(E)-2-phenylvinyl]-8-quinolinol core structure that stabilized p53. Surface plasmon resonance analysis indicated that these compounds bound p53 with a KD of 200 ± 52 nM. Furthermore, these compounds increased p53 nuclear localization and transcription of the p53 target genes PUMA, BAX, p21 and FAS in cancer cells. Although p53-null cells had a 2.5±0.5-fold greater viability compared to p53 wild type cells after treatment with core compounds, loss of p53 did not completely rescue cell viability suggesting that compounds may target both p53-dependent and p53-independent pathways to inhibit cell proliferation. Thus, we present a novel, cell-based high-throughput screen to identify a 2-[(E)-2-phenylvinyl]-8-quinolinol core structure that bound to p53 and increased p53 activity in cancer cells. These compounds may serve as anti-neoplastic agents in part by targeting p53 as well as other potential pathways. PMID:27124407

A homogeneous cell-based assay for measurement of endogenous paraoxonase 1 activity.

PubMed

Ahmad, Syed; Carter, Jade J; Scott, John E

2010-05-01

Paraoxonase 1 (PON1) is a high-density lipoprotein-associated enzyme that plays an important role in organophosphate detoxification and prevention of atherosclerosis. Thus, there is significant interest in identifying nutritional and pharmacological enhancers of PON1 activity. To identify such compounds, we developed a rapid homogeneous assay to detect endogenous cell-associated PON1 activity. PON1 activity was measured by the simple addition of fluorigenic PON1 substrate DEPFMU to live Huh7 cells in medium and monitoring change in fluorescence. A specific PON1 inhibitor, 2-hydroxyquinoline, was used to confirm that the observed activity was due to PON1. The assay was optimized and characterized with regard to time course, substrate and sodium chloride concentration, number of cells, and tolerance to dimethyl sulfoxide and serum. Aspirin, quercetin, and simvastatin are compounds reported to increase PON1 expression. Consistent with the literature and Western blot data, these compounds enhanced PON1 activity in this assay with comparable efficacies and potencies. A known toxic compound did not increase assay signal. This assay method also detected PON1 activity in normal hepatocytes. Thus, a novel homogeneous assay for detection of endogenous PON1 expression has been developed and is amenable to high-throughput screening for the identification of small molecules that enhance PON1 expression. 2010 Elsevier Inc. All rights reserved.

New Coumarin Derivatives as Potent Selective COX-2 Inhibitors: Synthesis, Anti-Inflammatory, QSAR, and Molecular Modeling Studies.

PubMed

Dawood, Dina H; Batran, Rasha Z; Farghaly, Thoraya A; Khedr, Mohammed A; Abdulla, Mohamed M

2015-12-01

Two new series of coumarin derivatives incorporating thiazoline and thiazolidinone moieties were designed, synthesized, and investigated in vivo for their anti-inflammatory activities using the carrageenan-induced rat paw edema model and in vitro for their inhibitory activities against the human cyclooxygenase (COX)-1 and COX-2 isoforms. Most of the synthesized compounds demonstrated exceptionally high in vivo anti-inflammatory activity and displayed superior GI safety profiles (0-7% ulceration) as compared to indomethacin. All the bioactive compounds showed in vitro high affinity and selectivity toward the COX-2 isoenzyme, compared to the reference celecoxib with IC50 values ranging from 0.31 to 0.78 μM. The ethyl thiosemicarbazone 2b, thiazoline derivatives 3a, 3b, 5b, 6a, and 7f, and the thiazolidinone compounds 8b and 9a showed the highest in vivo and in vitro anti-inflammatory activities with remarkable COX-2 selectivity. Quantitative structure-activity relationship study (QSAR) was done and resulted in a highly predictive power R(2) (0.908). A molecular docking study revealed a relationship between the docking affinity and the biological results. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessment of Inhibition of Ebola Virus Progeny Production by Antiviral Compounds.

PubMed

Falzarano, Darryl

2017-01-01

Assessment of small molecule compounds against filoviruses, such as Ebola virus, has identified numerous compounds that appear to have antiviral activity and should presumably be further investigated in animal efficacy trials. However, despite the many compounds that are purported to have good antiviral activity in in vitro studies, there are few instances where any efficacy has been reported in nonhuman primate models. Many of the high-throughput screening assays use reporter systems that only recapitulate a portion of the virus life cycle, while other assays only assess antiviral activity at relatively early time points. Moreover, many assays do not assess virus progeny production. A more in-depth evaluation of small numbers of test compounds is useful to economize resources and to generate higher quality antiviral hits. Assessing virus progeny production as late as 5 days post-infection allows for the elimination of compounds that have initial antiviral effects that are not sustained or where the virus rapidly develops resistance. While this eliminates many potential lead compounds that may be worthy of further structure-activity relationship (SAR) development, it also quickly excludes compounds that in their current form are unlikely to be effective in animal models. In addition, the inclusion of multiple assays that assess both cell viability and cell cytotoxicity, via different mechanisms, provides a more thorough assessment to exclude compounds that are not direct-acting antivirals.

Design, Synthesis, and Characterization of N-Oxide-Containing Heterocycles with in Vivo Sterilizing Antitubercular Activity

PubMed Central

2017-01-01

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), is the infectious disease responsible for the highest number of deaths worldwide. Herein, 22 new N-oxide-containing compounds were synthesized followed by in vitro and in vivo evaluation of their antitubercular potential against Mtb. Compound 8 was found to be the most promising compound, with MIC90 values of 1.10 and 6.62 μM against active and nonreplicating Mtb, respectively. Additionally, we carried out in vivo experiments to confirm the safety and efficacy of compound 8; the compound was found to be orally bioavailable and highly effective, leading to a reduction of Mtb to undetectable levels in a mouse model of infection. Microarray-based initial studies on the mechanism of action suggest that compound 8 blocks translation. Altogether, these results indicate that benzofuroxan derivative 8 is a promising lead compound for the development of a novel chemical class of antitubercular drugs. PMID:28968083

Removal of organic compounds from shale gas flowback water.

PubMed

Butkovskyi, Andrii; Faber, Ann-Hélène; Wang, Yue; Grolle, Katja; Hofman-Caris, Roberta; Bruning, Harry; Van Wezel, Annemarie P; Rijnaarts, Huub H M

2018-07-01

Ozonation, sorption to granular activated carbon and aerobic degradation were compared as potential treatment methods for removal of dissolved organic carbon (DOC) fractions and selected organic compounds from shale gas flowback water after pre-treatment in dissolved air flotation unit. Flowback water was characterised by high chemical oxygen demand and DOC. Low molecular weight (LMW) acids and neutral compounds were the most abundant organic fractions, corresponding to 47% and 35% of DOC respectively. Ozonation did not change distribution of organic carbon fractions and concentrations of detected individual organic compounds significantly. Sorption to activated carbon targeted removal of individual organic compounds with molecular weight >115 Da, whereas LMW compounds remained largely unaffected. Aerobic degradation was responsible for removal of LMW compounds and partial ammonium removal, whereas formation of intermediates with molecular weight of 200-350 Da was observed. Combination of aerobic degradation for LMW organics removal with adsorption to activated carbon for removal of non-biodegradable organics is proposed to be implemented between pre-treatment (dissolved air floatation) and desalination (thermal or membrane desalination) steps. Copyright © 2018 Elsevier Ltd. All rights reserved.

Human aldo-keto reductases 1B1 and 1B10: a comparative study on their enzyme activity toward electrophilic carbonyl compounds.

PubMed

Shen, Yi; Zhong, Linlin; Johnson, Stephen; Cao, Deliang

2011-05-30

Aldo-keto reductase family 1 member B1 (AKR1B1, 1B1 in brief) and aldo-keto reductase family 1 member B10 (AKR1B10, 1B10 in brief) are two proteins with high similarities in their amino acid sequences, stereo structures, and substrate specificity. However, these two proteins exhibit distinct tissue distributions; 1B10 is primarily expressed in the gastrointestinal tract and adrenal gland, whereas 1B1 is ubiquitously present in all tissues/organs, suggesting their difference in biological functions. This study evaluated in parallel the enzyme activity of 1B1 and 1B10 toward alpha, beta-unsaturated carbonyl compounds with cellular and dietary origins, including acrolein, crotonaldehyde, 4-hydroxynonenal, trans-2-hexenal, and trans-2,4-hexadienal. Our results showed that 1B10 had much better enzyme activity and turnover rates toward these chemicals than 1B1. By detecting the enzymatic products using high-performance liquid chromatography, we measured their activity to carbonyl compounds at low concentrations. Our data showed that 1B10 efficiently reduced the tested carbonyl compounds at physiological levels, but 1B1 was less effective. Ectopically expressed 1B10 in 293T cells effectively eliminated 4-hydroxynonenal at 5 μM by reducing to 1,4-dihydroxynonene, whereas endogenously expressed 1B1 did not. The 1B1 and 1B10 both showed enzyme activity to glutathione-conjugated carbonyl compounds, but 1B1 appeared more active in general. Together our data suggests that 1B10 is more effectual in eliminating free electrophilic carbonyl compounds, but 1B1 seems more important in the further detoxification of glutathione-conjugated carbonyl compounds. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

High Content Screening of a Kinase-Focused Library Reveals Compounds Broadly-Active against Dengue Viruses

PubMed Central

Li, Xiaolan; Milan Bonotto, Rafaela; No, Joo Hwan; Kim, Keum Hyun; Baek, Sungmin; Kim, Hee Young; Windisch, Marc Peter; Pamplona Mosimann, Ana Luiza; de Borba, Luana; Liuzzi, Michel; Hansen, Michael Adsetts Edberg; Nunes Duarte dos Santos, Claudia; Freitas-Junior, Lucio Holanda

2013-01-01

Dengue virus is a mosquito-borne flavivirus that has a large impact in global health. It is considered as one of the medically important arboviruses, and developing a preventive or therapeutic solution remains a top priority in the medical and scientific community. Drug discovery programs for potential dengue antivirals have increased dramatically over the last decade, largely in part to the introduction of high-throughput assays. In this study, we have developed an image-based dengue high-throughput/high-content assay (HT/HCA) using an innovative computer vision approach to screen a kinase-focused library for anti-dengue compounds. Using this dengue HT/HCA, we identified a group of compounds with a 4-(1-aminoethyl)-N-methylthiazol-2-amine as a common core structure that inhibits dengue viral infection in a human liver-derived cell line (Huh-7.5 cells). Compounds CND1201, CND1203 and CND1243 exhibited strong antiviral activities against all four dengue serotypes. Plaque reduction and time-of-addition assays suggests that these compounds interfere with the late stage of viral infection cycle. These findings demonstrate that our image-based dengue HT/HCA is a reliable tool that can be used to screen various chemical libraries for potential dengue antiviral candidates. PMID:23437413

Anti-biofilm and anti-adherence activities of sub fraction 18 of Melastoma malabathricum towards Streptococcus mutans

NASA Astrophysics Data System (ADS)

Rohazila M., H.; Nazlina, I.; Yaacob W., A.

2014-09-01

A study was carried out to isolate and identify the active compounds from Melastoma malabathricum stem bark that exhibit anti-biofilm and anti-adherence activities against Streptococcus mutans. Purification of the active compounds from the stem bark extract was performed via silica gel chromatography to produce 12 fractions. Further fractionation of fraction 9 by high performance liquid chromatography (HPLC) produced 21 sub fractions. All the sub fractions were subjected to thin layer chromatography (TLC) bioautography as preliminary screening to determine anti bacterial activity. TLC-bioautography showed that sub fraction 18 (SF18) demonstrated large inhibited zone against S. mutans. Gas chromatography mass spectrometry (GCMS) was used to identify the active compounds in SF18. Fraction SF18 revealed 27 compounds such as hexanoic acid, 8-methyl-1-undecene, propanenitrile, and 1-decene. Anti-biofilm and anti-adherence activities were determined using crystal violet and glass surface assays respectively. The concentrations that produced 50% reduction in anti-biofilm and anti-adherence activities were 1.88 mg/ml and 3.75 mg/ml respectively.

Study of antileishmanial activity of 2-aminobenzoyl amino acid hydrazides and their quinazoline derivatives.

PubMed

Khattab, Sherine Nabil; Haiba, Nesreen Saied; Asal, Ahmed Mosaad; Bekhit, Adnan A; Guemei, Aida A; Amer, Adel; El-Faham, Ayman

2017-02-15

A new small library of 2-aminobenzoyl amino acid hydrazide derivatives and quinazolinones derivatives was synthesized and fully characterized by IR, NMR, and elemental analysis. The activity of the prepared compounds on the growth of Leishmania aethiopica promastigotes was evaluated. 2-Benzoyl amino acid hydrazide showed higher inhibitory effect than the quinazoline counterpart. The in vitro antipromastigote activity demonstrated that compounds 2a, 2b, 2f and 4a had IC 50 better than standard drug miltefosine and comparable activity to amphotericin B deoxycholate, which indicates their high antileishmanial activity against Leishmania. aethiopica. Among the prepared compounds; 2-amino-N-(6-hydrazinyl-6-oxohexyl)benzamide 2f (IC 50 =0.051μM) has the best activity, 154 folds more active than reference standard drug miltefosine (IC 50 =7.832μM), and half fold the activity of amphotericin B (IC 50 =0.035μM). In addition, this compound was safe and well tolerated by experimental animals orally up to 250mg/kg and parenterally up to 100mg/kg. Copyright © 2017 Elsevier Ltd. All rights reserved.

Compound cycle engine program

NASA Technical Reports Server (NTRS)

Bobula, G. A.; Wintucky, W. T.; Castor, J. G.

1987-01-01

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded power plant which combines the lightweight pressure rise capability of a gas turbine with the high efficiency of a diesel. When optimized for a rotorcraft, the CCE will reduce fuel burn for a typical 2 hr (plus 30 min reserve) mission by 30 to 40 percent when compared to a conventional advanced technology gas turbine. The CCE can provide a 50 percent increase in range-payload product on this mission. A program to establish the technology base for a Compound Cycle Engine is presented. The goal of this program is to research and develop those technologies which are barriers to demonstrating a multicylinder diesel core in the early 1990's. The major activity underway is a three-phased contract with the Garrett Turbine Engine Company to perform: (1) a light helicopter feasibility study, (2) component technology development, and (3) lubricant and material research and development. Other related activities are also presented.

Compound cycle engine program

NASA Technical Reports Server (NTRS)

Bobula, G. A.; Wintucky, W. T.; Castor, J. G.

1986-01-01

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded power plant which combines the lightweight pressure rise capability of a gas turbine with the high efficiency of a diesel. When optimized for a rotorcraft, the CCE will reduce fuel burned for a typical 2 hr (plus 30 min reserve) mission by 30 to 40 percent when compared to a conventional advanced technology gas turbine. The CCE can provide a 50 percent increase in range-payload product on this mission. A program to establish the technology base for a Compound Cycle Engine is presented. The goal of this program is to research and develop those technologies which are barriers to demonstrating a multicylinder diesel core in the early 1990's. The major activity underway is a three-phased contract with the Garrett Turbine Engine Company to perform: (1) a light helicopter feasibility study, (2) component technology development, and (3) lubricant and material research and development. Other related activities are also presented.

High pressure extraction of phenolic compounds from citrus peels†

NASA Astrophysics Data System (ADS)

Casquete, R.; Castro, S. M.; Villalobos, M. C.; Serradilla, M. J.; Queirós, R. P.; Saraiva, J. A.; Córdoba, M. G.; Teixeira, P.

2014-10-01

This study evaluated the effect of high pressure processing on the recovery of high added value compounds from citrus peels. Overall, the total phenolic content in orange peel was significantly (P < .05) higher than that in lemon peel, except when pressure treated at 500 MPa. However, lemon peel demonstrated more antioxidant activity than orange peel. Pressure-treated samples (300 MPa, 10 min; 500 MPa, 3 min) demonstrated higher phenolic content and antioxidant activity comparatively to the control samples. For more severe treatments (500 MPa, 10 min), the phenolic content and antioxidant activity decreased in both lemon and orange peels. This paper was presented at the 8th International Conference on High Pressure Bioscience & Biotechnology (HPBB 2014), in Nantes (France), 15-18 July 2014.

Identification and quantification of phenolic compounds of selected fruits from Madeira Island by HPLC-DAD-ESI-MS(n) and screening for their antioxidant activity.

PubMed

Spínola, Vítor; Pinto, Joana; Castilho, Paula C

2015-04-15

Five fruits species commonly cultivated and consumed in Madeira Island (Portugal) were investigated for their phenolic profile by means of reversed phase high-performance liquid chromatography coupled to diode array detection and electrospray ionisation mass spectrometry (HPLC-DAD-ESI/MS(n)) and antioxidant potential. A large number of compounds were characterised, flavonoids and phenolic acids being the major components found in target samples, 39 compounds (flavonoids, phenolic acids, terpenoids, cyanogenic glycosides and organic acids) were identified in cherimoyas, lemons, papayas, passion-fruits and strawberries for the first time. Furthermore, all samples were systematically analysed for their total phenolic and flavonoid contents along with two radical scavenging methods (ABTS and ORAC) for antioxidant activity measurement. Target fruits presented high phenolic contents which is responsible for most of the antioxidant activity against radical reactive species (R(2)>0.80). Quantitative data showed that anthocyanins, in particular pelargonidin-3-O-hexoside (>300 mg/100 mL), present only in strawberries were the compounds in largest amounts but are the ones which contribute less to the antioxidant activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chimeric Derivatives of Functionalized Amino Acids and α-Aminoamides: Compounds with Anticonvulsant Activity in Seizure Models and Inhibitory Actions on Central, Peripheral, and Cardiac Isoforms of Voltage-gated Sodium Channels

PubMed Central

Torregrosa, Robert; Yang, Xiao-Fang; Dustrude, Erik T.; Cummins, Theodore R.

2015-01-01

Six novel 3″-substituted (R)-N-(phenoxybenzyl) 2-N-acetamido-3-methoxypropionamides were prepared and then assessed using whole-cell, patch-clamp electrophysiology for their anticonvulsant activities in animal seizure models and for their sodium channel activities. We found compounds with various substituents at the terminal aromatic ring that had excellent anticonvulsant activity. Of these compounds, (R)-N-4′-((3″-chloro)phenoxy)benzyl 2-N-acetamido-3-methoxypropionamide ((R)-5) and (R)-N-4′-((3″-trifluoromethoxy)phenoxy)benzyl 2-N-acetamido-3-methoxypropionamide ((R)-9) exhibited high protective indices (PI = TD50/ED50) comparable with many antiseizure drugs when tested in the maximal electroshock seizure test to mice (intraperitoneally) and rats (intraperitoneally, orally). Most compounds potently transitioned sodium channels to the slow-inactivated state when evaluated in rat embryonic cortical neurons. Treating HEK293 recombinant cells that expressed hNav1.1, rNav1.3, hNav1.5, or hNav1.7 with (R)-9 recapitulated the high levels of sodium channel slow inactivation. PMID:25922183

Design and synthesis of a series of bioavailable fatty acid synthase (FASN) KR domain inhibitors for cancer therapy.

PubMed

Lu, Tianbao; Schubert, Carsten; Cummings, Maxwell D; Bignan, Gilles; Connolly, Peter J; Smans, Karine; Ludovici, Donald; Parker, Michael H; Meyer, Christophe; Rocaboy, Christian; Alexander, Richard; Grasberger, Bruce; De Breucker, Sabine; Esser, Norbert; Fraiponts, Erwin; Gilissen, Ron; Janssens, Boudewijn; Peeters, Danielle; Van Nuffel, Luc; Vermeulen, Peter; Bischoff, James; Meerpoel, Lieven

2018-05-08

We designed and synthesized a new series of fatty acid synthase (FASN) inhibitors with potential utility for the treatment of cancer. Extensive SAR studies led to highly active FASN inhibitors with good cellular activity and oral bioavailability, exemplified by compound 34. Compound 34 is a potent inhibitor of human FASN (IC 50  = 28 nM) that effectively inhibits proliferation of A2780 ovarian cells (IC 50  = 13 nM) in lipid-reduced serum (LRS). This cellular activity can be rescued by addition of palmitate, consistent with an on-target effect. Compound 34 is also active in many other cell types, including PC3M (IC 50  = 25 nM) and LnCaP-Vancouver prostate cells (IC 50  = 66 nM), and is highly bioavailable (F 61%) with good exposure after oral administration. In a pharmacodynamics study in H460 lung xenograft-bearing mice, oral treatment with compound 34 results in elevated tumor levels of malonyl-CoA and decreased tumor levels of palmitate, fully consistent with the desired target engagement. Copyright © 2018 Elsevier Ltd. All rights reserved.

Introducing Bayesian thinking to high-throughput screening for false-negative rate estimation.

PubMed

Wei, Xin; Gao, Lin; Zhang, Xiaolei; Qian, Hong; Rowan, Karen; Mark, David; Peng, Zhengwei; Huang, Kuo-Sen

2013-10-01

High-throughput screening (HTS) has been widely used to identify active compounds (hits) that bind to biological targets. Because of cost concerns, the comprehensive screening of millions of compounds is typically conducted without replication. Real hits that fail to exhibit measurable activity in the primary screen due to random experimental errors will be lost as false-negatives. Conceivably, the projected false-negative rate is a parameter that reflects screening quality. Furthermore, it can be used to guide the selection of optimal numbers of compounds for hit confirmation. Therefore, a method that predicts false-negative rates from the primary screening data is extremely valuable. In this article, we describe the implementation of a pilot screen on a representative fraction (1%) of the screening library in order to obtain information about assay variability as well as a preliminary hit activity distribution profile. Using this training data set, we then developed an algorithm based on Bayesian logic and Monte Carlo simulation to estimate the number of true active compounds and potential missed hits from the full library screen. We have applied this strategy to five screening projects. The results demonstrate that this method produces useful predictions on the numbers of false negatives.

Combined strategy for phytotoxicity enhancement of benzoxazinones.

PubMed

Macías, Francisco A; Chinchilla, Nuria; Arroyo, Elena; Molinillo, José M G; Marín, David; Varela, Rosa M

2010-02-10

Fifteen new derivatives of D-DIBOA, including aromatic ring modifications and the addition of side chains in positions C-2 and N-4, were synthesized and their phytotoxicity, selectivity, and structure-activity relationships evaluated. The most active compounds among the derivatives at the C-2 position were 6-Cl-2-Et-D-DIBOA and 6-F-2-Et-D-DIBOA. Of the derivatives at N-4, the most active compounds were 6-Cl-4-Pr-D-DIBOA and 6-Cl-4-Val-D-DIBOA. These four compounds showed high levels of inhibition in root length at very low concentrations in all species. The most remarkable result is the 70% inhibition observed for the root length of cress at 100 nM caused by the latter two compounds. These results support our previous research and conclusions regarding the steric, electronic, and solubility requirements to achieve the maximum phytotoxic activity.

Use of early passage fetal intestinal epithelial cells in semi-high-throughput screening assays: an approach to identify new innate immune system adjuvants.

PubMed

Buckner, Diana; Wilson, Suzanne; Kurk, Sandra; Hardy, Michele; Miessner, Nicole; Jutila, Mark A

2006-09-01

Innate immune system stimulants (innate adjuvants) offer complementary approaches to vaccines and antimicrobial compounds to increase host resistance to infection. The authors established fetal bovine intestinal epithelial cell (BIEC) cultures to screen natural product and synthetic compound libraries for novel mucosal adjuvants. They showed that BIECs from fetal intestine maintained an in vivo phenotype as reflected in cytokeratin expression, expression of antigens restricted to intestinal enterocytes, and induced interleukin-8 (IL-8) production. BIECs could be infected by and support replication of bovine rotavirus. A semi-high-throughput enzyme-linked immunosorbent assay-based assay that measured IL-8 production by BIECs was established and used to screen commercially available natural compounds for novel adjuvant activity. Five novel hits were identified, demonstrating the utility of the assay for selecting and screening new epithelial cell adjuvants. Although the identified compounds had not previously been shown to induce IL-8 production in epithelial cells, other known functions for 3 of the 5 were consistent with this activity. Statistical analysis of the throughput data demonstrated that the assay is adaptable to a high-throughput format for screening both synthetic and natural product derived compound libraries.

A review of QSAR studies to discover new drug-like compounds actives against leishmaniasis and trypanosomiasis.

PubMed

Castillo-Garit, Juan Alberto; Abad, Concepción; Rodríguez-Borges, J Enrique; Marrero-Ponce, Yovani; Torrens, Francisco

2012-01-01

The neglected tropical diseases (NTDs) affect more than one billion people (one-sixth of the world's population) and occur primarily in undeveloped countries in sub-Saharan Africa, Asia, and Latin America. Available drugs for these diseases are decades old and present an important number of limitations, especially high toxicity and, more recently, the emergence of drug resistance. In the last decade several Quantitative Structure-Activity Relationship (QSAR) studies have been developed in order to identify new organic compounds with activity against the parasites responsible for these diseases, which are reviewed in this paper. The topics summarized in this work are: 1) QSAR studies to identify new organic compounds actives against Chaga's disease; 2) Development of QSAR studies to discover new antileishmanial drusg; 3) Computational studies to identify new drug-like compounds against human African trypanosomiasis. Each topic include the general characteristics, epidemiology and chemotherapy of the disease as well as the main QSAR approaches to discovery/identification of new actives compounds for the corresponding neglected disease. The last section is devoted to a new approach know as multi-target QSAR models developed for antiparasitic drugs specifically those actives against trypanosomatid parasites. At present, as a result of these QSAR studies several promising compounds, active against these parasites, are been indentify. However, more efforts will be required in the future to develop more selective (specific) useful drugs.

Synthesis and radical scavenging activity of 6-hydroxyl-4-methylcoumarin and its derivatives

NASA Astrophysics Data System (ADS)

Jumal, Juliana; Ayomide, Adetunji Fridaos

2018-06-01

Four compounds of coumarin derivatives namely 6-hydroxyl-4-methylcoumarin (I), 6-hydroxyl-4-methyl-5-(p-nitrophenyl azocoumarin) (II), 6-hydroxyl-4-methyl-5,7-(bis-p-nitrophenyl azocoumarin) (III) and 6-hydroxyl-4-methyl-5,7-(bis-p-chlorophenyl azocoumarin) (IV) were successfully synthesized. These compounds were prepared by reacting hydroquinone with ethylacetoacetate and selected anilines which are chloro and nitro aniline. All synthesized compounds were characterized by CHN micro-elemental analysis, 1H Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopic methods. The infrared spectra of these compounds exhibited five important stretching vibrations: ʋ(-OH), ʋ(C=O), ʋ(C=C), ʋ(C-O) and ʋ(C-N) at 3441-3359 cm-1, 1604-1632 cm-1, 1581-1496 cm-1, 1331-1225 cm-1, 1251-1109 cm-1, respectively. 1H NMR spectra of these compounds show the presence of proton aromatic, proton methyl and proton pyrone ring with the chemical shift at δH 7.00-8.70 ppm, δH 2.20-2.50 ppm and δH 6.10-6.90 ppm, respectively. CHN analysis results of all compounds are in good agreement with the calculated values. All the synthesized compounds were evaluated for their antioxidant activity using DPPH method and ascorbic acid used as the standard. UV-Vis spectroscopic technique was used to investigate the absorbance of these compounds. Compound (II) shows high antioxidant activities compared to compound (I), (III) and (IV) which show moderate to low activities.

Chemical Variability and Biological Activities of Brassica rapa var. rapifera Parts Essential Oils Depending on Geographic Variation and Extraction Technique.

PubMed

Saka, Boualem; Djouahri, Abderrahmane; Djerrad, Zineb; Terfi, Souhila; Aberrane, Sihem; Sabaou, Nasserdine; Baaliouamer, Aoumeur; Boudarene, Lynda

2017-06-01

In the present work, the Brassica rapa var. rapifera parts essential oils and their antioxidant and antimicrobial activities were investigated for the first time depending on geographic origin and extraction technique. Gas-chromatography (GC) and GC/mass spectrometry (MS) analyses showed several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, terpenic, nitrogen and sulphur compounds, totalizing 38 and 41 compounds in leaves and root essential oils, respectively. Nitrogen compounds were the main volatiles in leaves essential oils and sulphur compounds were the main volatiles in root essential oils. Qualitative and quantitative differences were found among B. rapa var. rapifera parts essential oils collected from different locations and extracted by hydrodistillation and microwave-assisted hydrodistillation techniques. Furthermore, our findings showed a high variability for both antioxidant and antimicrobial activities. The highlighted variability reflects the high impact of plant part, geographic variation and extraction technique on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on these factors, in order to isolate the bioactive components or to have the best quality of essential oil in terms of biological activities and preventive effects in food. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Biotransformation of macrolide antibiotics using enriched activated sludge culture: Kinetics, transformation routes and ecotoxicological evaluation.

PubMed

Terzic, Senka; Udikovic-Kolic, Nikolina; Jurina, Tamara; Krizman-Matasic, Ivona; Senta, Ivan; Mihaljevic, Ivan; Loncar, Jovica; Smital, Tvrtko; Ahel, Marijan

2018-05-05

The biotransformation of three prominent macrolide antibiotics (azithromycin, clarithromycin and erythromycin) by an activated sludge culture, which was adapted to high concentrations of azithromycin (10 mg/L) was investigated. The study included determination of removal kinetics of the parent compounds, identification of their major biotransformation products (TPs) and assessment of ecotoxicological effects of biotransformation. The chemical analyses were performed by ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry, which enabled a tentative identification of TPs formed during the experiments. The ecotoxicological evaluation included two end-points, residual antibiotic activity and toxicity to freshwater algae. The enriched activated sludge culture was capable of degrading all studied macrolide compounds with high removal efficiencies (>99%) of the parent compounds at elevated concentrations (10 mg/L). The elimination of all three macrolide antibiotics was associated with the formation of different TPs, including several novel compounds previously unreported in the literature. Some of the TPs were rather abundant and contributed significantly to the overall mass balance at the end of the biodegradation experiments. Biodegradation of all investigated macrolides was associated with a pronounced reduction of the residual antibiotic activity and algal toxicity, indicating a rather positive ecotoxicological outcome of the biotransformation processes achieved by the enriched sludge culture. Copyright © 2018 Elsevier B.V. All rights reserved.

Antimicrobial active herbal compounds against Acinetobacter baumannii and other pathogens.

PubMed

Tiwari, Vishvanath; Roy, Ranita; Tiwari, Monalisa

2015-01-01

Bacterial pathogens cause a number of lethal diseases. Opportunistic bacterial pathogens grouped into ESKAPE pathogens that are linked to the high degree of morbidity, mortality and increased costs as described by Infectious Disease Society of America. Acinetobacter baumannii is one of the ESKAPE pathogens which cause respiratory infection, pneumonia and urinary tract infections. The prevalence of this pathogen increases gradually in the clinical setup where it can grow on artificial surfaces, utilize ethanol as a carbon source and resists desiccation. Carbapenems, a β-lactam, are the most commonly prescribed drugs against A. baumannii. The high level of acquired and intrinsic carbapenem resistance mechanisms acquired by these bacteria makes their eradication difficult. The pharmaceutical industry has no solution to this problem. Hence, it is an urgent requirement to find a suitable alternative to carbapenem, a commonly prescribed drug for Acinetobacter infection. In order to do this, here we have made an effort to review the active compounds of plants that have potent antibacterial activity against many bacteria including carbapenem resistant strain of A. baumannii. We have also briefly highlighted the separation and identification methods used for these active compounds. This review will help researchers involved in the screening of herbal active compounds that might act as a replacement for carbapenem.

UPLC-Q-TOF-MS analysis of non-volatile migrants from new active packaging materials.

PubMed

Aznar, M; Rodriguez-Lafuente, A; Alfaro, P; Nerin, C

2012-10-01

Ultra-performance liquid chromatography (UPLC) coupled to mass spectrometry (MS) is a useful tool in the analysis of non-volatile compounds, and the use of a quadrupole-time-of-flight (Q-TOF) mass analyzer allows a high sensitivity and accuracy when acquiring full fragment mode, providing a high assurance of correct identification of unknown compounds. In this work, UPLC-Q-TOF-MS technology has been applied to the analysis of non-volatile migrants from new active packaging materials. The materials tested were based on polypropylene (PP), ethylene-vinyl alcohol copolymer (EVOH), and poly(ethylene terephthalate) (PET). The active packaging materials studied were one PP film containing a natural antioxidant, and two PP/EVOH films, two PET/EVOH films and one coextruded PP/EVOH/PP film containing natural antimicrobials. The chemical structure of several compounds was unequivocally identified. The analysis revealed the migration of some of the active substances used in the manufacture of active packaging, such as caffeine (0.07 ± 0.01 μg/g), carvacrol (0.31 ± 0.03 μg/g) and citral (0.20 ± 0.01 μg/g). Unintentionally added substances were also found, such as citral reaction compounds, or citral impurities present in the raw materials.

Simultaneous screening of four epidermal growth factor receptor antagonists from Curcuma longa via cell membrane chromatography online coupled with HPLC-MS.

PubMed

Sun, Meng; Ma, Wei-na; Guo, Ying; Hu, Zhi-gang; He, Lang-chong

2013-07-01

The epidermal growth factor receptors (EGFRs) are significant targets for screening active compounds. In this work, an analytical method was established for rapid screening, separation, and identification of EGFRs antagonists from Curcuma longa. Human embryonic kidney 293 cells with a steadily high expression of EGFRs were used to prepare the cell membrane stationary phase in a cell membrane chromatography model for screening active compounds. Separation and identification of the retention chromatographic peaks was achieved by HPLC-MS. The active sites, docking extents and inhibitory effects of the active compounds were also demonstrated. The screening result found that ar-turmerone, curcumin, demethoxycurcumin, and bisdemethoxycurcumin from Curcuma longa could be active components in a similar manner to gefitinib. Biological trials showed that all of four compounds can inhibit EGFRs protein secretion and cell growth in a dose-dependent manner, and downregulate the phosphorylation of EGFRs. This analytical method demonstrated fast and effective characteristics for screening, separation and identification of the active compounds from a complex system and should be useful for drug discovery with natural medicinal herbs. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Total Synthesis of Marine Cyclic Enol-Phosphotriester Salinipostin Compounds

NASA Astrophysics Data System (ADS)

Zhao, Mingliang; Wei, Xianfeng; Liu, Xuemeng; Dong, Xueyang; Yu, Rilei; Wan, Shengbiao; Jiang, Tao

2018-06-01

Due to their structural diversity and variety of biological activities, marine natural products have been the subject of extensive study. These compounds, especially phospholipid polycyclic aromatic hydrocarbons, have a wide range of pharmacological applications, including embedded DNA and central nervous system, anti-tumor, anti-virus, anti-parasite, anti-bacterial, and antithrombotic effects. Unfortunately, the insufficient drug sources have limited the development of these compounds. In this study, we isolated salinpostin compounds from a fermentation solution of marine-derived Salinospora sp., which has a common bicyclic enol-phosphotriester core framework, as well as potent and selective antimalarial activities against P. falciparum with EC50 = 50 nmol L-1. The chemical synthesis of these compounds in greater quantities is necessary for their use in bioactivity studies. Thus we explored a short route with high yields and mild reaction conditions, which can generate combinatorial libraries for drug discovery and lead optimization. We developed a new total synthesis method for six cyclic enol-phosphotriester salinipotin compounds and their diastereomers. For the total synthesis of cyclipostin P, we prepared cyclic enol-phosphotriester salinipostin compounds in 10 steps from a readily accessible starting material, 1,3-dihydroxyacetone, and obtained an overall yield of 1.29%. We fully characterized these compounds by proton nuclear magnetic resonance (1H-NMR), carbon-13 NMR (13C-NMR), and high-resolution mass spectrometry (HRMS) analyses, and found they coincide absolutely with the same compounds reported previously.

Antioxidant and antimicrobial activity of natural phenolic extract from defatted soybean flour by-product for stone fruit postharvest application.

PubMed

Villalobos, María del Carmen; Serradilla, Manuel Joaquín; Martín, Alberto; Ordiales, Elena; Ruiz-Moyano, Santiago; Córdoba, María de Guía

2016-04-01

Fresh fruit is highly perishable during storage and transport, so there has been growing interest in finding safe and natural antimicrobial compounds as a control tool. Phenolic compounds are secondary metabolites naturally present in vegetable material and have been associated with antimicrobial and antioxidant properties. Therefore, the aim of this study was to investigate the antioxidant capacity and potential antimicrobial effect of phenolic extract obtained from defatted soybean flour against selected pathogenic bacteria and microorganisms responsible of fruit decay. Analysis of phenolic composition by HPLC-MS showed the presence of a wide range of compounds, with isoflavones and phenolic acids the main polyphenols identified. Furthermore, the phenolic extract had important antioxidant activity by two different assays. Related to antimicrobial activity, in vitro experiments demonstrated that phenolic extract displayed a high activity against the main foodborne pathogens, while a moderate inhibition was found against five spoilage yeasts and Monilia laxa and a scarce effect for Penicillium glabrum, Cladosporium uredinicola and Botrytis cinerea. Interestingly these compounds considerably inhibited the mycelial growth of Monilia laxa, in both in vitro and in vivo experiments. The results of the present study revealed that defatted soybean flour is an important source of phenolic compounds with remarkable antimicrobial and antioxidant activity, suggesting the possibility of using them as natural additives in postharvest treatments to extend the shelf life of fruit. © 2015 Society of Chemical Industry.

Fruit wastes fermentation for phenolic antioxidants production and their application in manufacture of edible coatings and films.

PubMed

Martinez-Avila, G C G; Aguilera, A F; Saucedo, S; Rojas, R; Rodriguez, R; Aguilar, C N

2014-01-01

Agro-industrial by-products are important sources of potent bioactive phenolic compounds. These compounds are of extreme relevance for food and pharmacological industries due to their great variety of biological activities. Fermentation represents an environmentally clean technology for production and extraction of these bioactive compounds, providing high quality and high activity extracts, which can be incorporated in foods using coatings/films wax-based in order to avoid alterations in their quality. In this document is presented an overview about importance and benefits of solid-state fermentation, pointing out this bioprocess as an alternative technology for use agro-industrial by-products as substrates to produce valuable secondary metabolites and their applications as food quality conservatives.

Isolation and anti-HIV-1 integrase activity of lentzeosides A-F from extremotolerant lentzea sp. H45, a strain isolated from a high-altitude Atacama Desert soil.

PubMed

Wichner, Dominik; Idris, Hamidah; Houssen, Wael E; McEwan, Andrew R; Bull, Alan T; Asenjo, Juan A; Goodfellow, Michael; Jaspars, Marcel; Ebel, Rainer; Rateb, Mostafa E

2017-04-01

The extremotolerant isolate H45 was one of several actinomycetes isolated from a high-altitude Atacama Desert soil collected in northwest Chile. The isolate was identified as a new Lentzea sp. using a combination of chemotaxonomic, morphological and phylogenetic properties. Large scale fermentation of the strain in two different media followed by chromatographic purification led to the isolation of six new diene and monoene glycosides named lentzeosides A-F, together with the known compound (Z)-3-hexenyl glucoside. The structures of the new compounds were confirmed by HRESIMS and NMR analyses. Compounds 1-6 displayed moderate inhibitory activity against HIV integrase.

Discrimination of Swiss cheese from 5 different factories by high impact volatile organic compound profiles determined by odor activity value using selected ion flow tube mass spectrometry and odor threshold.

PubMed

Taylor, Kaitlyn; Wick, Cheryl; Castada, Hardy; Kent, Kyle; Harper, W James

2013-10-01

Swiss cheese contains more than 200 volatile organic compounds (VOCs). Gas chromatography-mass spectrometry has been utilized for the analysis of volatile compounds in food products; however, it is not sensitive enough to measure VOCs directly in the headspace of a food at low concentrations. Selected ion flow tube mass spectrometry (SIFT-MS) provides a basis for determining the concentrations of VOCs in the head space of the sample in real time at low concentration levels of parts per billion/trillion by volume. Of the Swiss cheese VOCs, relatively few have a major impact on flavor quality. VOCs with odor activity values (OAVs) (concentration/odor threshold) greater than one are considered high-impact flavor compounds. The objective of this study was to utilize SIFT-MS concentrations in conjunction with odor threshold values to determine OAVs thereby identifying high-impact VOCs to use for differentiating Swiss cheese from five factories and identify the factory variability. Seventeen high-impact VOCs were identified for Swiss cheese based on an OAV greater than one in at least 1 of the 5 Swiss cheese factories. Of these, 2,3-butanedione was the only compound with significantly different OAVs in all factories; however, cheese from any pair of factories had multiple statistically different compounds based on OAV. Principal component analysis using soft independent modeling of class analogy statistical differentiation plots, with all of the OAVs, showed differentiation between the 5 factories. Overall, Swiss cheese from different factories was determined to have different OAV profiles utilizing SIFT-MS to determine OAVs of high impact compounds. © 2013 Institute of Food Technologists®

A novel compound inhibits rHDL assembly and blocks nascent HDL biogenesis downstream of apoAI binding to ABCA1 expressing cells

PubMed Central

Lyssenko, Nicholas N.; Brubaker, Gregory; Smith, Bradley D.; Smith, Jonathan D.

2011-01-01

Objective Nascent high-density lipoprotein (HDL) particles form from cellular lipids and extracellular lipid-free apolipoprotein AI (apoAI) in a process mediated by ATP-binding cassette transporter A1 (ABCA1). We have sought out compounds that inhibit nascent HDL biogenesis without affecting ABCA1 activity. Methods and Results Reconstituted HDL (rHDL) formation and cellular cholesterol efflux assays were used to show that two compounds that bond via hydrogen with phospholipids inhibit rHDL and nascent HDL production. In rHDL formation assays, the inhibitory effect of compound 1 (methyl 3α-acetoxy-7α,12α-di[(phenylaminocarbonyl)amino]-5β-cholan-24-oate), the more active of the two, depended on its ability to associate with phospholipids. In cell assays, compound 1 suppressed ABCA1-mediated cholesterol efflux to apoAI, the 18A peptide, and taurocholate with high specificity, without affecting ABCA1-independent cellular cholesterol efflux to HDL and endocytosis of acetylated low-density lipoprotein (AcLDL) and transferrin. Furthermore, compound 1 did not affect ABCA1 activity adversely, as ABCA1-mediated shedding of microparticles proceeded unabated and apoAI binding to ABCA1-expressing cells increased in its presence. Conclusions The inhibitory effects of compound 1 support a three-step model of nascent HDL biogenesis: plasma membrane remodeling by ABCA1, apoAI binding to ABCA1, and lipoprotein particle assembly. The compound inhibits the final step, causing accumulation of apoAI in ABCA1-expressing cells. PMID:21836073

DPubChem: a web tool for QSAR modeling and high-throughput virtual screening.

PubMed

Soufan, Othman; Ba-Alawi, Wail; Magana-Mora, Arturo; Essack, Magbubah; Bajic, Vladimir B

2018-06-14

High-throughput screening (HTS) performs the experimental testing of a large number of chemical compounds aiming to identify those active in the considered assay. Alternatively, faster and cheaper methods of large-scale virtual screening are performed computationally through quantitative structure-activity relationship (QSAR) models. However, the vast amount of available HTS heterogeneous data and the imbalanced ratio of active to inactive compounds in an assay make this a challenging problem. Although different QSAR models have been proposed, they have certain limitations, e.g., high false positive rates, complicated user interface, and limited utilization options. Therefore, we developed DPubChem, a novel web tool for deriving QSAR models that implement the state-of-the-art machine-learning techniques to enhance the precision of the models and enable efficient analyses of experiments from PubChem BioAssay database. DPubChem also has a simple interface that provides various options to users. DPubChem predicted active compounds for 300 datasets with an average geometric mean and F 1 score of 76.68% and 76.53%, respectively. Furthermore, DPubChem builds interaction networks that highlight novel predicted links between chemical compounds and biological assays. Using such a network, DPubChem successfully suggested a novel drug for the Niemann-Pick type C disease. DPubChem is freely available at www.cbrc.kaust.edu.sa/dpubchem .

Analysis of Active Methylotrophic Communities: When DNA-SIP Meets High-Throughput Technologies.

PubMed

Taubert, Martin; Grob, Carolina; Howat, Alexandra M; Burns, Oliver J; Chen, Yin; Neufeld, Josh D; Murrell, J Colin

2016-01-01

Methylotrophs are microorganisms ubiquitous in the environment that can metabolize one-carbon (C1) compounds as carbon and/or energy sources. The activity of these prokaryotes impacts biogeochemical cycles within their respective habitats and can determine whether these habitats act as sources or sinks of C1 compounds. Due to the high importance of C1 compounds, not only in biogeochemical cycles, but also for climatic processes, it is vital to understand the contributions of these microorganisms to carbon cycling in different environments. One of the most challenging questions when investigating methylotrophs, but also in environmental microbiology in general, is which species contribute to the environmental processes of interest, or "who does what, where and when?" Metabolic labeling with C1 compounds substituted with (13)C, a technique called stable isotope probing, is a key method to trace carbon fluxes within methylotrophic communities. The incorporation of (13)C into the biomass of active methylotrophs leads to an increase in the molecular mass of their biomolecules. For DNA-based stable isotope probing (DNA-SIP), labeled and unlabeled DNA is separated by isopycnic ultracentrifugation. The ability to specifically analyze DNA of active methylotrophs from a complex background community by high-throughput sequencing techniques, i.e. targeted metagenomics, is the hallmark strength of DNA-SIP for elucidating ecosystem functioning, and a protocol is detailed in this chapter.

Identification of Potential Pharmacoperones Capable of Rescuing the Functionality of Misfolded Vasopressin 2 Receptor Involved in Nephrogenic Diabetes Insipidus.

PubMed

Smith, Emery; Janovick, Jo Ann; Bannister, Thomas D; Shumate, Justin; Scampavia, Louis; Conn, P Michael; Spicer, Timothy P

2016-09-01

Pharmacoperones correct the folding of otherwise misfolded protein mutants, restoring function (i.e., providing "rescue") by correcting their trafficking. Currently, most pharmacoperones possess intrinsic antagonist activity because they were identified using methods initially aimed at discovering such functions. Here, we describe an ultra-high-throughput homogeneous cell-based assay with a cAMP detection system, a method specifically designed to identify pharmacoperones of the vasopressin type 2 receptor (V2R), a GPCR that, when mutated, is associated with nephrogenic diabetes insipidus. Previously developed methods to identify compounds capable of altering cellular trafficking of V2R were modified and used to screen a 645,000 compound collection by measuring the ability of library compounds to rescue a mutant hV2R [L83Q], using a cell-based luminescent detection system. The campaign initially identified 3734 positive modulators of cAMP. The confirmation and counterscreen identified only 147 of the active compounds with an EC50 of ≤5 µM. Of these, 83 were reconfirmed as active through independently obtained pure samples and were also inactive in a relevant counterscreen. Active and tractable compounds within this set can be categorized into three predominant structural clusters, described here, in the first report detailing the results of a large-scale pharmacoperone high-throughput screening campaign. © 2016 Society for Laboratory Automation and Screening.

Can Invalid Bioactives Undermine Natural Product-Based Drug Discovery?

PubMed Central

2015-01-01

High-throughput biology has contributed a wealth of data on chemicals, including natural products (NPs). Recently, attention was drawn to certain, predominantly synthetic, compounds that are responsible for disproportionate percentages of hits but are false actives. Spurious bioassay interference led to their designation as pan-assay interference compounds (PAINS). NPs lack comparable scrutiny, which this study aims to rectify. Systematic mining of 80+ years of the phytochemistry and biology literature, using the NAPRALERT database, revealed that only 39 compounds represent the NPs most reported by occurrence, activity, and distinct activity. Over 50% are not explained by phenomena known for synthetic libraries, and all had manifold ascribed bioactivities, designating them as invalid metabolic panaceas (IMPs). Cumulative distributions of ∼200,000 NPs uncovered that NP research follows power-law characteristics typical for behavioral phenomena. Projection into occurrence–bioactivity–effort space produces the hyperbolic black hole of NPs, where IMPs populate the high-effort base. PMID:26505758

Identification of didecyldimethylammonium salts and salicylic acid as antimicrobial compounds in commercial fermented radish kimchi.

PubMed

Li, Jing; Chaytor, Jennifer L; Findlay, Brandon; McMullen, Lynn M; Smith, David C; Vederas, John C

2015-03-25

Daikon radish (Raphanus sativus) fermented with lactic acid bacteria, especially Leuconostoc or Lactobacillus spp., can be used to make kimchi, a traditional Korean fermented vegetable. Commercial Leuconostoc/radish root ferment filtrates are claimed to have broad spectrum antimicrobial activity. Leuconostoc kimchii fermentation products are patented as preservatives for cosmetics, and certain strains of this organism are reported to produce antimicrobial peptides (bacteriocins). We examined the antimicrobial agents in commercial Leuconostoc/radish root ferment filtrates. Both activity-guided fractionation with Amberlite XAD-16 and direct extraction with ethyl acetate gave salicylic acid as the primary agent with activity against Gram-negative bacteria. Further analysis of the ethyl acetate extract revealed that a didecyldimethylammonium salt was responsible for the Gram-positive activity. The structures of these compounds were confirmed by a combination of (1)H- and (13)C NMR, high-performance liquid chromatography, high-resolution mass spectrometry, and tandem mass spectrometry analyses. Radiocarbon dating indicates that neither compound is a fermentation product. No antimicrobial peptides were detected.

Antimicrobial and Anti-Inflammatory Activities of Endophytic Fungi Talaromyces wortmannii Extracts against Acne-Inducing Bacteria

PubMed Central

Schwendinger, Katja; Kreiseder, Birgit; Wiederstein, Martina; Pretsch, Dagmar; Genov, Miroslav; Hollaus, Ralph; Zinssmeister, Daniela; Debbab, Abdesamad; Hundsberger, Harald; Eger, Andreas; Proksch, Peter; Wiesner, Christoph

2014-01-01

Acne vulgaris is the most common skin disease, causing significant psychosocial problems such as anxiety and depression similar to a chronic illness for those afflicted. Currently, obtainable agents for acne treatment have limited use. Thus, development of novel agents to treat this disease is a high medical need. The anaerobic bacterium Propionibacterium acnes has been implicated in the inflammatory phase of acne vulgaris by activating pro-inflammatory mediators such as the interleukin-8 (IL-8) via the NF-κB and MAPK pathways. Talaromyces wortmannii is an endophytic fungus, which is known to produce high bioactive natural compounds. We hypothesize that compound C but also the crude extract from T. wortmannii may possess both antibacterial activity especially against P. acnes and also anti-inflammatory properties by inhibiting TNF-α-induced ICAM-1 expression and P. acnes-induced IL-8 release. Treatment of keratinocytes (HaCaT) with P. acnes significantly increased NF-κB and activator protein-1 (AP-1) activation, as well as IL-8 release. Compound C inhibited P. acnes-mediated activation of NF-κB and AP-1 by inhibiting IκB degradation and the phosphorylation of ERK and JNK MAP kinases, and IL-8 release in a dose-dependent manner. Based on these results, compound C has effective antimicrobial activity against P. acnes and anti-inflammatory activity, and we suggest that this substance or the crude extract are alternative treatments for antibiotic/anti-inflammatory therapy for acne vulgaris. PMID:24887557

Low toxic and high soluble camptothecin derivative 2–47 effectively induces apoptosis of tumor cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Yao; Zhao, Hong-Ye; Jiang, Du

The cytotoxic activity of camptothecin derivatives is so high that these compounds need to be further modified before their successful application as anti-cancer agents clinically. In this study, we reported the synthesis and biological evaluation of a novel camptothecin derivative called compound 2–47. The changes in structure did not reduce its activity to inhibit DNA topoisomerase I. Compound 2–47 induced apoptosis of many tumor cells including leukemia cells K562, Jurkat, HL-60, breast cancer cell BT-549, colon cancer cell HT-29 and liver cancer cell HepG2 with a half maximal inhibitory concentration (IC{sub 50}) of 2- to 3-fold lower than HCPT asmore » a control. In particular, 2–47 inhibited the proliferation of Jurkat cells with an IC{sub 50} of as low as 40 nM. By making use of Jurkat cell as a model, following treatment of Jurkat cells, compound 2–47 activated caspase-3 and PARP, resulting in a decreased Bcl-2/Bax ratio. These data showed that compound 2–47 induces Jurkat cell death through the mitochondrial apoptotic pathway. In addition, compound 2–47 showed a decreased cytotoxic activity against normal cells and an improved solubility in low-polar solvent. For example, compound 2–47 solutes in CHCl{sub 3} 130-fold higher than HCPT. Taken together, our data demonstrated that camptothecin derivative 2–47 notably inhibits the tumor cell proliferation through mitochondrial-mediated apoptosis in vitro. - Highlights: • Compound 2–47 showed a wide inhibitory effect on the tested tumor cell lines with an IC{sub 50} of 3 times lower than that of HCPT in general. • Compound 2–47 inhibited the proliferation of the human leukemia cell Jurkat at an IC{sub 50} of as low as 40 nM. • As compared to HCPT, compound 2–47 showed much reduced cytotoxicity on normal human cells. • As compared to others, compound 2–47 showed a hundreds-fold higher solubility in non-polar organic solution.« less

Phenolic compounds, organic acids and antioxidant activity of grape juices produced from new Brazilian varieties planted in the Northeast Region of Brazil.

PubMed

Lima, Marcos Dos Santos; Silani, Igor de Souza Veras; Toaldo, Isabela Maia; Corrêa, Luiz Claudio; Biasoto, Aline Camarão Telles; Pereira, Giuliano Elias; Bordignon-Luiz, Marilde T; Ninow, Jorge Luiz

2014-10-15

The phenolic compounds, organic acids and the antioxidant activity were determined for grape juice samples from new Brazilian varieties grown in the Sub-middle São Francisco Valley in the Northeast Region of Brazil. The results showed that the Brazilian grape juices have high antioxidant activity, which was significantly correlated with the phenolic compounds catechin, epicatechin gallate, procyanidin B1, rutin, gallic acid, caffeic acid, p-coumaric acid, pelargonidin-3-glucoside, cyanidin-3-glucoside, cyaniding-3,5-diglucoside and delphinidin-3-glucoside. The produced juice samples showed higher concentrations of trans-resveratrol than those observed in juices made from different varieties of grapes from traditional growing regions. Organic acids concentrations were similar to those of juices produced from other classical varieties. It was demonstrated that it is possible to prepare juices from grapes of new varieties grown in the Northeast of Brazil containing a high content of bioactive compounds and typical characteristics of the tropical viticulture practised in the Sub-middle São Francisco Valley. Copyright © 2014 Elsevier Ltd. All rights reserved.

SYNTHESIZING ORGANIC COMPOUNDS USING LIGHT-ACTIVATED TIO2

EPA Science Inventory

High-value organic compounds have been synthesized successfully from linear and cyclic hydrocarbons, by photocatalytic oxidation using a semiconductor material, titanium dioxide (TiO2). Various hydrocarbons were partially oxgenated in both liquid and gaseous phase reactors usi...

Antidyslipidemic effect and antioxidant activity of anthraquinone derivatives from Rheum emodi rhizomes in dyslipidemic rats.

PubMed

Mishra, Sunil K; Tiwari, Shashi; Shrivastava, Atul; Srivastava, Shishir; Boudh, Goutam K; Chourasia, Shivendra K; Chaturvedi, Upma; Mir, Snober S; Saxena, Anil K; Bhatia, Gitika; Lakshmi, Vijai

2014-04-01

The aim of the present study was to evaluate the antidyslipidemic effect of ethanolic extract of Rheum emodi rhizomes and its constituents in Triton-WR-1339 and high-fat diet (HFD)-induced dyslipidemic rats. In preliminary screening, the ethanolic extract showed significant activity in Triton-treated rats. Bioassay-guided fractionation of the ethanolic extract resulted in the identification of four anthraquinone derivatives, viz. chrysophanol, emodin, chrysophanol 8-O-β-D-glucopyranoside and emodin 8-O-β-D-glucopyranoside as active constituents. All these compounds significantly reduced plasma lipid levels. The most active compound emodin showed significant lipid-lowering activity in the HFD-fed model. In addition, these compounds showed significant antioxidant activity. The effect of emodin on enzymes modulating lipid metabolism confirms and supports the efficiency of emodin as a potent antidyslipidemic agent.

HPLC-Based Activity Profiling for GABAA Receptor Modulators in Searsia pyroides Using a Larval Zebrafish Locomotor Assay.

PubMed

Moradi-Afrapoli, Fahimeh; van der Merwe, Hannes; De Mieri, Maria; Wilhelm, Anke; Stadler, Marco; Zietsman, Pieter C; Hering, Steffen; Swart, Kenneth; Hamburger, Matthias

2017-10-01

A dichloromethane extract from leaves of Searsia pyroides potentiated gamma aminobutyric acid-induced chloride currents by 171.8 ± 54% when tested at 100 µg/mL in Xenopus oocytes transiently expressing gamma aminobutyric acid type A receptors composed of α 1 β 2 γ 2 s subunits. In zebrafish larvae, the extract significantly lowered pentylenetetrazol-provoked locomotion when tested at 4 µg/mL. Active compounds of the extract were tracked with the aid of HPLC-based activity profiling utilizing a previously validated zebrafish larval locomotor activity assay. From two active HPLC fractions, compounds 1  -  3 were isolated. Structurally related compounds 4  -  6 were purified from a later eluting inactive HPLC fraction. With the aid of 1 H and 13 C NMR and high-resolution mass spectrometry, compounds 1  -  6 were identified as analogues of anacardic acid. Compounds 1  -  3 led to a concentration-dependent decrease of pentylenetetrazol-provoked locomotion in the zebrafish larvae model, while 4  -  6 were inactive. Compounds 1  -  3 enhanced gamma aminobutyric acid-induced chloride currents in Xenopus oocytes in a concentration-dependent manner, while 4  -  6 only showed marginal enhancements of gamma aminobutyric acid-induced chloride currents. Compounds 2, 3 , and 5 have not been reported previously. Georg Thieme Verlag KG Stuttgart · New York.

Rapid screening of bioactive compounds from natural products by integrating 5-channel parallel chromatography coupled with on-line mass spectrometry and microplate based assays.

PubMed

Zhang, Yufeng; Xiao, Shun; Sun, Lijuan; Ge, Zhiwei; Fang, Fengkai; Zhang, Wen; Wang, Yi; Cheng, Yiyu

2013-05-13

A high throughput method was developed for rapid screening and identification of bioactive compounds from traditional Chinese medicine, marine products and other natural products. The system, integrated with five-channel chromatographic separation and dual UV-MS detection, is compatible with in vitro 96-well microplate based bioassays. The stability and applicability of the proposed method was validated by testing radical scavenging capability of a mixture of seven known compounds (rutin, dihydroquercetin, salvianolic acid A, salvianolic acid B, glycyrrhizic acid, rubescensin A and tangeretin). Moreover, the proposed method was successfully applied to the crude extracts of traditional Chinese medicine and a marine sponge from which 12 bioactive compounds were screened and characterized based on their anti-oxidative or anti-tumor activities. In particular, two diterpenoid derivatives, agelasine B and (-)-agelasine D, were identified for the first time as anti-tumor compounds from the sponge Agelas mauritiana, showing a considerable activity toward MCF-7 cells (IC50 values of 7.84±0.65 and 10.48±0.84 μM, respectively). Our findings suggested that the integrated system of 5-channel parallel chromatography coupled with on-line mass spectrometry and microplate based assays can be a versatile and high efficient approach for the discovery of active compounds from natural products. Copyright © 2013 Elsevier B.V. All rights reserved.

In vitro anticancer activity of Betulinic acid and derivatives thereof on equine melanoma cell lines from grey horses and in vivo safety assessment of the compound NVX-207 in two horses.

PubMed

Liebscher, G; Vanchangiri, K; Mueller, Th; Feige, K; Cavalleri, J-M V; Paschke, R

2016-02-25

Betulinic acid, a pentacyclic triterpene, and its derivatives are promising compounds for cancer treatment in humans. Melanoma is not only a problem for humans but also for grey horses as they have a high potential of developing melanoma lesions coupled to the mutation causing their phenotype. Current chemotherapeutic treatment carries the risk of adverse health effects for the horse owner or the treating veterinarian by exposure to antineoplastic compounds. Most treatments have low prospects for systemic tumor regression. Thus, a new therapy is needed. In this in vitro study, Betulinic acid and its two derivatives B10 and NVX-207, both with an improved water solubility compared to Betulinic acid, were tested on two equine melanoma cell lines (MelDuWi and MellJess/HoMelZh) and human melanoma (A375) cell line. We could demonstrate that all three compounds especially NVX-207 show high cytotoxicity on both equine melanoma cell lines. The treatment with these compounds lead to externalization of phosphatidylserines on the cell membrane (AnnexinV-staining), DNA-fragmentation (cell cycle analysis) and activation of initiator and effector caspases (Caspase assays). Our results indicate that the apoptosis is induced in the equine melanoma cells by all three compounds. Furthermore, we succeed in encapsulating the most active compound NVX-207 in 2-Hydroxyprolyl-β-cyclodextrine without a loss of its activity. This formulation can be used as a promising antitumor agent for treating grey horse melanoma. In a first tolerability evaluation in vivo the formulation was administered every one week for 19 consecutive weeks and well tolerated in two adult melanoma affected horses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme in bean (Phaseolus vulgaris L.) grown under different nitrogen conditions.

PubMed

Pinto, M E; Casati, P; Hsu, T P; Ku, M S; Edwards, G E

1999-02-01

The effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme have been examined in different cultivars of Phaseolous vulgaris L. grown under 1 and 12 mM nitrogen. Low nitrogen nutrition reduces chlorophyll and soluble protein contents in the leaves and thus the photosynthesis rate and dry-matter accumulation. Chlorophyll, soluble protein and Rubisco contents and photosynthesis rate are not significantly altered by ambient levels of UV-B radiation (17 microW m-2, 290-320 nm, 4 h/day for one week). Comparative studies show that under high nitrogen, UV-B radiation slightly enhances leaf expansion and dry-matter accumulation in cultivar Pinto, but inhibits these parameters in Vilmorin. These results suggest that the UV-B effect on growth is mediated through leaf expansion, which is particularly sensitive to UV-B, and that Pinto is more tolerant than Vilmorin. The effect of UV-B radiation on UV-B-absorbing compounds and on NADP-malic enzyme (NADP-ME) activity is also examined. Both UV-B radiation and low-nitrogen nutrition enhance the content of UV-B-absorbing compounds, and among the three cultivars used, Pinto exhibits the highest increases and Arroz the lowest. The same trend is observed for the specific activity and content of NADP-ME. On a leaf-area basis, the amount of UV-B-absorbing compounds is highly correlated with the enzyme activity (r2 = 0.83), suggesting that NADP-ME plays a key role in biosynthesis of these compounds. Furthermore, the higher sensitivity of Vilmorin than Pinto to UV-B radiation appears to be related to the activity of NADP-ME and the capacity of the plants to accumulate UV-B-absorbing compounds.

A Data Analysis Pipeline Accounting for Artifacts in Tox21 Quantitative High-Throughput Screening Assays

PubMed Central

Hsieh, Jui-Hua; Sedykh, Alexander; Huang, Ruili; Xia, Menghang; Tice, Raymond R.

2015-01-01

A main goal of the U.S. Tox21 program is to profile a 10K-compound library for activity against a panel of stress-related and nuclear receptor signaling pathway assays using a quantitative high-throughput screening (qHTS) approach. However, assay artifacts, including nonreproducible signals and assay interference (e.g., autofluorescence), complicate compound activity interpretation. To address these issues, we have developed a data analysis pipeline that includes an updated signal noise–filtering/curation protocol and an assay interference flagging system. To better characterize various types of signals, we adopted a weighted version of the area under the curve (wAUC) to quantify the amount of activity across the tested concentration range in combination with the assay-dependent point-of-departure (POD) concentration. Based on the 32 Tox21 qHTS assays analyzed, we demonstrate that signal profiling using wAUC affords the best reproducibility (Pearson's r = 0.91) in comparison with the POD (0.82) only or the AC50 (i.e., half-maximal activity concentration, 0.81). Among the activity artifacts characterized, cytotoxicity is the major confounding factor; on average, about 8% of Tox21 compounds are affected, whereas autofluorescence affects less than 0.5%. To facilitate data evaluation, we implemented two graphical user interface applications, allowing users to rapidly evaluate the in vitro activity of Tox21 compounds. PMID:25904095

The Inhibitory Effect of Natural Products on Protein Fibrillation May Be Caused by Degradation Products--A Study Using Aloin and Insulin.

PubMed

Lobbens, Eva S; Foderà, Vito; Nyberg, Nils T; Andersen, Kirsten; Jäger, Anna K; Jorgensen, Lene; van de Weert, Marco

2016-01-01

Protein fibrillation is the pathological hallmark of several neurodegenerative diseases and also complicates the manufacturing and use of protein drugs. As a case study, the inhibitory activity of the natural compound aloin against insulin fibrillation was investigated. Based on Thioflavin T assays, high-performance liquid chromatography and transmission electron microscopy it was found that a degradation product of aloin, formed over weeks of storage, was able to significantly inhibit insulin fibrillation. The activity of the stored aloin was significantly reduced in the presence of small amounts of sodium azide or ascorbic acid, suggesting the active compound to be an oxidation product. A high-performance liquid chromatography method and a liquid chromatography-mass spectrometry method were developed to investigate the degradation products in the aged aloin solution. We found that the major compounds in the solution were aloin A and aloin B. In addition, 10-hydroxy aloin and elgonica dimers were detected in smaller amounts. The identified compounds were isolated and tested for activity by means of Thioflavin T assays, but no activity was observed. Thus, the actual fibrillation inhibitor is an as yet unidentified and potentially metastable degradation product of aloin. These results suggest that degradation products, and in particular oxidation products, are to be considered thoroughly when natural products are investigated for activity against protein fibrillation.

A Data Analysis Pipeline Accounting for Artifacts in Tox21 Quantitative High-Throughput Screening Assays.

PubMed

Hsieh, Jui-Hua; Sedykh, Alexander; Huang, Ruili; Xia, Menghang; Tice, Raymond R

2015-08-01

A main goal of the U.S. Tox21 program is to profile a 10K-compound library for activity against a panel of stress-related and nuclear receptor signaling pathway assays using a quantitative high-throughput screening (qHTS) approach. However, assay artifacts, including nonreproducible signals and assay interference (e.g., autofluorescence), complicate compound activity interpretation. To address these issues, we have developed a data analysis pipeline that includes an updated signal noise-filtering/curation protocol and an assay interference flagging system. To better characterize various types of signals, we adopted a weighted version of the area under the curve (wAUC) to quantify the amount of activity across the tested concentration range in combination with the assay-dependent point-of-departure (POD) concentration. Based on the 32 Tox21 qHTS assays analyzed, we demonstrate that signal profiling using wAUC affords the best reproducibility (Pearson's r = 0.91) in comparison with the POD (0.82) only or the AC(50) (i.e., half-maximal activity concentration, 0.81). Among the activity artifacts characterized, cytotoxicity is the major confounding factor; on average, about 8% of Tox21 compounds are affected, whereas autofluorescence affects less than 0.5%. To facilitate data evaluation, we implemented two graphical user interface applications, allowing users to rapidly evaluate the in vitro activity of Tox21 compounds. © 2015 Society for Laboratory Automation and Screening.

Identification of novel peroxisome proliferator-activated receptor-gamma (PPARγ) agonists using molecular modeling method

NASA Astrophysics Data System (ADS)

Gee, Veronica M. W.; Wong, Fiona S. L.; Ramachandran, Lalitha; Sethi, Gautam; Kumar, Alan Prem; Yap, Chun Wei

2014-11-01

Peroxisome proliferator-activated receptor-gamma (PPARγ) plays a critical role in lipid and glucose homeostasis. It is the target of many drug discovery studies, because of its role in various disease states including diabetes and cancer. Thiazolidinediones, a synthetic class of agents that work by activation of PPARγ, have been used extensively as insulin-sensitizers for the management of type 2 diabetes. In this study, a combination of QSAR and docking methods were utilised to perform virtual screening of more than 25 million compounds in the ZINC library. The QSAR model was developed using 1,517 compounds and it identified 42,378 potential PPARγ agonists from the ZINC library, and 10,000 of these were selected for docking with PPARγ based on their diversity. Several steps were used to refine the docking results, and finally 30 potentially highly active ligands were identified. Four compounds were subsequently tested for their in vitro activity, and one compound was found to have a K i values of <5 μM.

Three new phenylpropanoids from Lavandula angustifolia and their bioactivities.

PubMed

Tang, Shiyun; Shi, Jianlian; Liu, Chunbo; Jiang, Rui; Zhao, Wei; Liu, Xin; Xiang, Nengjun; Chen, Yongkuan; Shen, Qinpeng; Miao, Mingming; Liu, Zhihua; Yang, Guangyu

2017-06-01

Three new phenylpropanoids, 3-(3,4-dimethoxy-5-methylphenyl)-3-oxopropyl acetate (1), 3-hydroxy-1-(3,4-dimethoxy-5-methylphenyl)propan-1-one (2), and 3-hydroxy-1-(4-methylbenzo[d][1,3]dioxol-6-yl) propan-1-one (3), together with three known phenylpropanoids (4-6) were isolated from the whole plant of Lavandula angustifolia. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1-6 were tested for their anti-tobacoo mosaic virus (TMV) activities and cytotoxicity activities. The results revealed that compounds 1-3 showed high anti-TMV activity with inhibition rate of 35.2, 38.4 and 33.9%. These rates are higher than that of positive control. The other compounds also showed potential anti-TMV activities with inhibition rates in the range of 26.8-28.9%, respectively. Compounds 1-6 also showed weak inhibitory activities against some tested human tumour cell lines with IC50 values in the range of 3.8-8.8 μM.

Jasmonate signaling in plant stress responses and development - active and inactive compounds.

PubMed

Wasternack, Claus; Strnad, Miroslav

2016-09-25

Jasmonates (JAs) are lipid-derived signals mediating plant responses to biotic and abiotic stresses and in plant development. Following the elucidation of each step in their biosynthesis and the important components of perception and signaling, several activators, repressors and co-repressors have been identified which contribute to fine-tuning the regulation of JA-induced gene expression. Many of the metabolic reactions in which JA participates, such as conjugation with amino acids, glucosylation, hydroxylation, carboxylation, sulfation and methylation, lead to numerous compounds with different biological activities. These metabolites may be highly active, partially active in specific processes or inactive. Hydroxylation, carboxylation and sulfation inactivate JA signaling. The precursor of JA biosynthesis, 12-oxo-phytodienoic acid (OPDA), has been identified as a JA-independent signaling compound. An increasing number of OPDA-specific processes is being identified. To conclude, the numerous JA compounds and their different modes of action allow plants to respond specifically and flexibly to alterations in the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Design and Synthesis of Curcumin-Like Diarylpentanoid Analogues as Potential Anticancer Agents.

PubMed

Qudjani, Elahe; Iman, Maryam; Davood, Asghar; Ramandi, Mahdi F; Shafiee, Abbas

2016-01-01

Curcumin is a polyphenolic natural compound with multiple targets that used for the prophylaxis and treatment of some type of cancers like cervical and pancreatic cancers. Some recent patent for curcumin for cancer has also been reviewed. In this study, ten new curcumin derivatives were designed and synthesized and their cytostatic activity evaluated against the Hela and Panc cell lines that some of them showed more activity than curcumin. In the present study, a series of mono-carbonyl derivatives of curcumin were designed and prepared. The details of the synthesis and chemical characterization of the synthesized compounds are described. The cytostatic activities of the designed compounds are assessed in two different tumor cell lines using MTT test. In vitro screening for human cervix carcinoma cell lines (Hela) and pancreatic cell lines (Panc-1) at 24 and 48 hour showed that all the analogs possessed good activity against these tumor cell lines and compounds 5a, 5c and 6 with high potency can be used as a new lead compounds for the designing and finding new and potent cytostatic agents. Docking studies indicated that compound 5c readily binds the active site of human glyoxalase I protein via two strong hydrogen bonds engaging residues of Glu-99 and Lys-156. Our results are useful in guiding a design of optimized ligands with improved pharmacokinetic properties and increased of anti-cancer activity vs. the prototype curcumin compound.

Antioxidant Activity of Phenolic Compounds from Fava Bean Sprouts.

PubMed

Okumura, Koharu; Hosoya, Takahiro; Kawarazaki, Kai; Izawa, Norihiko; Kumazawa, Shigenori

2016-06-01

Fava beans are eaten all over the world and recently, marketing for their sprouts began in Japan. Fava bean sprouts contain more polyphenols and l-3,4-dihydroxyphenylalanine (l-DOPA) than the bean itself. Our antioxidant screening program has shown that fava bean sprouts also possess a higher antioxidant activity than other commercially available sprouts and mature beans. However, the individual constituents of fava bean sprouts are not entirely known. In the present study, we investigated the phenolic compounds of fava bean sprouts and their antioxidant activity. Air-dried fava bean sprouts were treated with 80% methanol and the extract was partitioned in water with chloroform and ethyl acetate. HPLC analysis had shown that the ethyl acetate-soluble parts contained phenolic compounds, separated by preparative HPLC to yield 5 compounds (1-5). Structural analysis using NMR and MS revealed that the compounds isolated were kaempferol glycosides. All isolated compounds had an α-rhamnose at the C-7 position with different sugars attached at the C-3 position. Compounds 1-5 had β-galactose, β-glucose, α-rhamnose, 6-acetyl-β-galactose and 6-acetyl-β-glucose, respectively, at the C-3 position. The amount of l-DOPA in fava bean sprouts was determined by the quantitative (1) H NMR technique. The l-DOPA content was 550.45 mg ± 11.34 /100 g of the raw sprouts. The antioxidant activities of compounds 2-5 and l-DOPA were evaluated using the 2,2-diphenyl-1-picrylhydrazyl scavenging assay. l-DOPA showed high antioxidant activity, but the isolated kaempferol glycosides showed weak activity. Therefore, it can be suggested that l-DOPA contributed to the antioxidant activity of fava bean sprouts. © 2016 Institute of Food Technologists®

Synthesis of modified steroids as a novel class of non-ulcerogenic, anti-inflammatory and anti-nociceptive agents.

PubMed

Mohareb, Rafat M; Elmegeed, Gamal A; Abdel-Salam, Omar M E; Doss, Senot H; William, Marian G

2011-01-01

The identification of compounds able to treat both pain and inflammation with limited side effects is one of the prominent goals in biomedical research. This study aimed at the synthesis of new modified steroids with structures justifying non-ulcerogenic, anti-inflammatory and anti-nociceptive activities. The steroid derivatives were synthesized via straightforward and efficient methods and their structures were established based on the analytical and spectral data. The in vivo anti-inflammatory, anti-nociceptive and anti-ulcerogenic activities of some of these compounds were studied. The newly synthesized compounds 8b, 19b, 24 and 31a showed anti-inflammatory, anti-nociceptive and anti-ulcerogenic activity with various intensities. Oedema was significantly reduced by either dose 25 or 50 mg/kg of all tested compounds at 3 and 4 h post-carrageenan. Compound 19b was the most effective in alleviating thermal pain. The analgesic activity of either dose of the compounds 8b, 24, 31a as well as the high dose 19b was significantly higher than that for indomethacin (IND). Gastric mucosal lesions caused in the rats by the administration of 96% EtOH and IND were inhibited by all tested compounds administered at (50 mg/kg) dose in the study. Copyright © 2011 Elsevier Inc. All rights reserved.

Hammerhead ribozyme activity and oligonucleotide duplex stability in mixed solutions of water and organic compounds

PubMed Central

Nakano, Shu-ichi; Kitagawa, Yuichi; Miyoshi, Daisuke; Sugimoto, Naoki

2014-01-01

Nucleic acids are useful for biomedical targeting and sensing applications in which the molecular environment is different from that of a dilute aqueous solution. In this study, the influence of various types of mixed solutions of water and water-soluble organic compounds on RNA was investigated by measuring the catalytic activity of the hammerhead ribozyme and the thermodynamic stability of an oligonucleotide duplex. The compounds with a net neutral charge, such as poly(ethylene glycol), small primary alcohols, amide compounds, and aprotic solvent molecules, added at high concentrations changed the ribozyme-catalyzed RNA cleavage rate, with the magnitude of the effect dependent on the NaCl concentration. These compounds also changed the thermodynamic stability of RNA base pairs of an oligonucleotide duplex and its dependence on the NaCl concentration. Specific interactions with RNA molecules and reduced water activity could account for the inhibiting effects on the ribozyme catalysis and destabilizing effects on the duplex stability. The salt concentration dependence data correlated with the dielectric constant, but not with water activity, viscosity, and the size of organic compounds. This observation suggests the significance of the dielectric constant effects on the RNA reactions under molecular crowding conditions created by organic compounds. PMID:25161873

Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties.

PubMed

Yehye, Wageeh A; Abdul Rahman, Noorsaadah; Saad, Omar; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A; Kadir, Farkaad A; Yaeghoobi, Marzieh; Matlob, Abdulsalam A

2016-06-28

A new series of multipotent antioxidants (MPAOs), namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT) were designed and subsequently synthesized. The structure-activity relationship (SAR) of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS). The antioxidant activities of the synthesized compounds 4-10 were tested by the DPPH bioassay. The synthesized compounds 4-10 inhibited stable DPPH free radicals at a level that is 10(-4) M more than the well-known standard antioxidant BHT. Compounds 8-10 with para-substituents were less active than compounds 4 and 5 with trimethoxy substituents compared to those with a second BHT moiety (compounds 6 and 7). With an IC50 of 46.13 ± 0.31 µM, compound 6 exhibited the most promising in vitro inhibition at 89%. Therefore, novel MPAOs containing active triazole rings, thioethers, Schiff bases, and BHT moieties are suggested as potential antioxidants for inhibiting oxidative stress processes and scavenging free radicals, hence, this combination of functions is anticipated to play a vital role in repairing cellular damage, preventing various human diseases and in medical therapeutic applications.

Fused heterocyclic compounds bearing bridgehead nitrogen as potent HIV-1 NNRTIs. Part 1: design, synthesis and biological evaluation of novel 5,7-disubstituted pyrazolo[1,5-a]pyrimidine derivatives.

PubMed

Tian, Ye; Du, Deping; Rai, Diwakar; Wang, Liu; Liu, Huiqing; Zhan, Peng; De Clercq, Erik; Pannecouque, Christophe; Liu, Xinyong

2014-04-01

In our continuous efforts to identify novel potent HIV-1 NNRTIs, a novel class of 5,7-disubstituted pyrazolo[1,5-a]pyrimidine derivatives were rationally designed, synthesized and evaluated for their anti-HIV activities in MT4 cell cultures. Biological results showed that most of the tested compounds displayed excellent activity against wild-type HIV-1 with a wide range of EC50 values from 5.98 to 0.07μM. Among the active compounds, 5a was found to be the most promising analogue with an EC50 of 0.07μM against wild-type HIV-1 and very high selectivity index (SI, 3999). Compound 5a was more effective than the reference drugs nevirapine (by 2-fold) and delavirdine (by 2-fold). In order to further confirm their binding target, an HIV-1 RT inhibitory assay was also performed. Furthermore, SAR analysis among the newly synthesized compounds was discussed and the binding mode of the active compound 5a was rationalized by molecular modeling studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Peptaibols, tetramic acid derivatives, isocoumarins, and sesquiterpenes from a Bionectria sp. (MSX 47401).

PubMed

Figueroa, Mario; Raja, Huzefa; Falkinham, Joseph O; Adcock, Audrey F; Kroll, David J; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

2013-06-28

An extract of the filamentous fungus Bionectria sp. (MSX 47401) showed both promising cytotoxic activity (>90% inhibition of H460 cell growth at 20 μg/mL) and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). A bioactivity-directed fractionation study yielded one new peptaibol (1) and one new tetramic acid derivative (2), and the fungus biosynthesized diverse secondary metabolites with mannose-derived units. Five known compounds were also isolated: clonostachin (3), virgineone (4), virgineone aglycone (5), AGI-7 (6), and 5,6-dihydroxybisabolol (7). Compounds 5 and 7 have not been described previously from natural sources. Compound 1 represents the second member of the peptaibol structural class that contains an ester-linked sugar alcohol (mannitol) instead of an amide-linked amino alcohol, and peptaibols and tetramic acid derivatives have not been isolated previously from the same fungus. The structures of the new compounds were elucidated primarily by high-field NMR (950 and 700 MHz), HRESIMS/MS, and chemical degradations (Marfey's analysis). All compounds (except 6) were examined for antibacterial and antifungal activities. Compounds 2, 4, and 5 showed antimicrobial activity against S. aureus and several MRSA isolates.

[Effect of compound gardenia oil and jujube seed oil on learning and memory in ovariectomized rats].

PubMed

Chen, Ya-Hui; Lan, Zhong-Ping; Fu, Zhao-Ying; Li, Bao-Li; Zhang, Zheng-Xiang

2013-09-01

To observe the effect of compound of gardenia oil and jujube seed oil learning and memory in ovariectomized rats and its mechanism. Animals were randomly divided into six groups: sham group, model group, estrogen group, low dose group, middle dose group and high dose group. The ovariectomized rat models were established by resection of the lateral ovaries. The effect of compound of gardenia oil and jujube seed oil on learning and memory in ovariectomized rats was observed by means of Morris water maze. Acetylcholinesterase (AchE) and nitric oxide synthase (NOS) activities in rat brain were determined. The compound of gardenia oil and jujube seed oil could shorten the incubation period of appearance in castration rats and increase the number passing through Yuan Ping table in ovariectomized rats. As the training time extended, the incubation period of appearance was gradually shortened. The compound of gardenia oil and jujube seed oil could increase NOS activity, and decrease AChE activity in brain of ovariectomized rats. The compound of jujube seed oil and gardenia oil could promote the learning and memory in ovariectomized rats. This effect may be related with the increase in activities of NOS, AchE in rat brain.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate.

PubMed

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines' couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, (1)H-NMR, (13)C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16-64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate

PubMed Central

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines’ couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, 1H-NMR, 13C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16–64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants. PMID:27583034

Isolation, characterization and HPLC quantification of compounds from Aquilegia fragrans Benth: Their in vitro antibacterial activities against bovine mastitis pathogens.

PubMed

Mushtaq, Saleem; Aga, Mushtaq A; Qazi, Parvaiz H; Ali, Md Niamat; Shah, Aabid Manzoor; Lone, Sajad Ahmad; Shah, Aiyatullah; Hussain, Aehtesham; Rasool, Faheem; Dar, Hafizullah; Shah, Zeeshan Hamid; Lone, Shabir H

2016-02-03

The underground parts of Aquilegia fragrans are traditionally used for the treatment of wounds and various inflammatory diseases like bovine mastitis. However, there are no reports on the phytochemical characterization and antibacterial studies of A. fragrans. To isolate compounds from the methanol extract of the underground parts of A. fragrans and determine their antibacterial activity against the pathogens of bovine mastitis. The study was undertaken in order to scientifically validate the traditional use of A. fragrans. Five compounds were isolated from the methanol extract of the underground parts of A. fragrans using silica gel column chromatography. Structural elucidation of the isolated compounds was done using spectral data analysis and comparison with literature. High performance liquid chromatography (HPLC) was used for the qualitative and quantitative determination of isolated compounds in the crude methanol extract. The methanol extract and isolated compounds were evaluated for antibacterial activities against mastitis pathogens using broth micro-dilution technique. The five isolated compounds were identified as (1) 2, 4-dihydroxyphenylacetic acid methyl ester (2) β-sitosterol (3) Aquilegiolide (4) Glochidionolactone-A and (5) Magnoflorine. A quick and sensitive HPLC method was developed for the first time for qualitative and quantitative determination of four isolated marker compounds from A. fragrans. The crude methanol extract and compound 5 exhibited weak antibacterial activities that varied between the bacterial species (MIC=500-3000 µg/ml). The above results show that the crude methanol extract and isolated compounds from A. fragrans exhibit weak antibacterial activities. Further phytochemical and pharmacological studies are required for proper scientific validation of the folk use of this plant species in the treatment of various inflammatory diseases like bovine mastitis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Discovery of the glycogen phosphorylase-modulating activity of a resveratrol glucoside by using a virtual screening protocol optimized for solvation effects.

PubMed

Mavrokefalos, Nikolaos; Myrianthopoulos, Vassilios; Chajistamatiou, Aikaterini S; Chrysina, Evangelia D; Mikros, Emmanuel

2015-04-01

The identification of natural products that can modulate blood glucose levels is of great interest as it can possibly facilitate the utilization of mild interventions such as herbal medicine or functional foods in the treatment of chronic diseases like diabetes. One of the established drug targets for antihyperglycemic therapy is glycogen phosphorylase. To evaluate the glycogen phosphorylase inhibitory properties of an in-house compound collection consisting to a large extent of natural products, a stepwise virtual and experimental screening protocol was devised and implemented. The fact that the active site of glycogen phosphorylase is highly hydrated emphasized that a methodological aspect needed to be efficiently addressed prior to an in silico evaluation of the compound collection. The effect of water molecules on docking calculations was regarded as a key parameter in terms of virtual screening protocol optimization. Statistical analysis of 125 structures of glycogen phosphorylase and solvent mapping focusing on the active site hydration motif in combination with a retrospective screening revealed the importance of a set of 29 crystallographic water molecules for achieving high enrichment as to the discrimination between active compounds and inactive decoys. The scaling of Van der Waals radii of system atoms had an additional effect on screening performance. Having optimized the in silico protocol, a prospective evaluation of the in-house compound collection derived a set of 18 top-ranked natural products that were subsequently evaluated in vitro for their activity as glycogen phosphorylase inhibitors. Two phenolic glucosides with glycogen phosphorylase-modulating activity were identified, whereas the most potent compound affording mid-micromolar inhibition was a glucosidic derivative of resveratrol, a stilbene well-known for its wide range of biological activities. Results show the possible phytotherapeutic and nutraceutical potential of products common in the Mediterranean countries, such as red wine and Vitis products in general or green raw salads and herbal preparations, where such compounds are abundant. Georg Thieme Verlag KG Stuttgart · New York.

Comparative Analysis of Chemical Composition, Antioxidant Activity and Quantitative Characterization of Some Phenolic Compounds in Selected Herbs and Spices in Different Solvent Extraction Systems.

PubMed

Sepahpour, Shabnam; Selamat, Jinap; Abdul Manap, Mohd Yazid; Khatib, Alfi; Abdull Razis, Ahmad Faizal

2018-02-13

This study evaluated the efficacy of various organic solvents (80% acetone, 80% ethanol, 80% methanol) and distilled water for extracting antioxidant phenolic compounds from turmeric, curry leaf, torch ginger and lemon grass extracts. They were analyzed regarding the total phenol and flavonoid contents, antioxidant activity and concentration of some phenolic compounds. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and the ferric reducing antioxidant power (FRAP) assay. Quantification of phenolic compounds was carried out using high-performance liquid chromatography (HPLC). All the extracts possessed antioxidant activity, however, the different solvents showed different efficiencies in the extraction of phenolic compounds. Turmeric showed the highest DPPH values (67.83-13.78%) and FRAP (84.9-2.3 mg quercetin/g freeze-dried crude extract), followed by curry leaf, torch ginger and lemon grass. While 80% acetone was shown to be the most efficient solvent for the extraction of total phenolic compounds from turmeric, torch ginger and lemon grass (221.68, 98.10 and 28.19 mg GA/g freeze dried crude extract, respectively), for the recovery of phenolic compounds from curry leaf (92.23 mg GA/g freeze-dried crude extract), 80% ethanol was the most appropriate solvent. Results of HPLC revealed that the amount of phenolic compounds varied depending on the types of solvents used.

Novel tetracyclic benzo[b]carbazolones as highly potent and orally bioavailable ALK inhibitors: design, synthesis, and structure-activity relationship study.

PubMed

Jiang, Xiaolong; Zhou, Ji; Ai, Jing; Song, Zilan; Peng, Xia; Xing, Li; Xi, Yong; Guo, Junfeng; Yao, Qizheng; Ding, Jian; Geng, Meiyu; Zhang, Ao

2015-11-13

Four series of tetracyclic benzo[b]carbazolone compounds possessing more rotatable bonds and higher molecular flexibility were designed by either inserting a linker within the C8-side chain or by opening the middle ketone ring on the basis of compound 5 (Alectinib, CH5424802). Compound 15b was identified showing nearly identical high potency against both wild-type and the gatekeeper mutant ALK kinase (3.4 vs 3.9 nM). This compound has favorable PK profile with an oral bioavailability of 67.1% in rats. Moreover, compound 15b showed significant growth inhibition against ALK driven cancer cells and KARPAS-299 xenograft model. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

IDENTIFYING COMPOUNDS DESPITE CHROMATOGRAPHY LIMITATIONS: ORGANOPHOSPHATES IN TREATED SEWAGE

EPA Science Inventory

Highly concentrated extracts of sewage treatment plant (STP) effluents contain detectable
levels of dozens of compounds resulting from human activities. Recent concern over use and
disposal of Pharmaceuticals and Personal Care Products (PPCPS) (1) has stimulated interest ...

In view of an optimal gut antifungal therapeutic strategy: an in vitro susceptibility and toxicity study testing a novel phyto-compound.

PubMed

Metugriachuk, Yussef; Kuroi, Olivia; Pavasuthipaisit, Kanok; Tsuchiya, Junji; Minelli, Emilio; Okura, Ruichi; Fesce, Edoardo; Marotta, F

2005-01-01

In view of the raising concern for gut fungal infection, the aim of the present research was to carry out a systematic in vitro study testing the antifungal activity and possible toxicity of a polygodyal-anethole compound (Kolorex) in several strains of Candida albicans and in other fungal pathogens. The in vitro susceptibility tests were carried out on 4 strains of C. albicans (C. krusei, C. lipolytica, C. tropicalis, C. utilis), Aspergillus flavus and A. fumigatus. Cultures were also analyzed by varying medium, pH and inoculum size, and a time-course killing test was carried out. In the present study the polygodyal-anethole compound showed remarkable in vitro activity against the most common fungi, which was significantly better than polygodyal alone. Moreover, such mixture compound was shown to exert its activity against a wide spectrum of fungi, including C. lipolytica and C. tropicalis, which required significantly higher MIC of polygodyal to be unfeasible in clinical application. The activity of the polygodyal-anethole compound was significantly better than polygodyal alone with high inoculum size and low pH. Moreover, it proved to exert a significantly faster biological activity against low inoculum. This study suggests that the mixture compound Kolorex has a very good profile of antifungal activity in terms of effectiveness and spectrum of action while being devoid of any significant toxicity.

Identification of Novel Synthetic Toll-like Receptor 2 Agonists by High Throughput Screening*

PubMed Central

Guan, Yue; Omueti-Ayoade, Katherine; Mutha, Sarita K.; Hergenrother, Paul J.; Tapping, Richard I.

2010-01-01

Toll-like receptors (TLRs) play a central role in host defense by inducing inflammatory and adaptive immune responses following infection. Drugs that target TLRs are of considerable interest as potential inflammatory regulators, vaccine adjuvants, and novel immunotherapeutics. TLR2, in cooperation with either TLR1 or TLR6, mediates responses to a wide variety of microbial products as well as products of host tissue damage. In an effort to understand the structural basis of TLR2 recognition and uncover novel TLR2 agonists, a synthetic chemical library of 24,000 compounds was screened using an IL-8-driven luciferase reporter in cells expressing these human receptors. The screening yielded several novel TLR2-dependent activators that utilize TLR1, TLR6, or both as co-receptors. These novel small molecule compounds are aromatic in nature and structurally unrelated to any known TLR2 agonists. The three most potent compounds do not exhibit synergistic activity, nor do they act as pseudoantagonists toward natural TLR2 activators. Interestingly, two of the compounds exhibit species specificity and are inactive toward murine peritoneal macrophages. Mutational analysis reveals that although the central extracellular region of TLR1 is required for stimulation, there are subtle differences in the mechanism of stimulation mediated by the synthetic compounds in comparison with natural lipoprotein agonists. The three most potent compounds activate cells in the nanomolar range and stimulate cytokine production from human peripheral blood monocytes. Our results confirm the utility of high throughput screens to uncover novel synthetic TLR2 agonists that may be of therapeutic benefit. PMID:20504771

Analysis of phytochemical profile of Terminalia arjuna bark extract with antioxidative and antimicrobial properties

PubMed Central

Mandal, Shreya; Patra, Arpita; Samanta, Animesh; Roy, Suchismita; Mandal, Arpita; Mahapatra, Tapasi Das; Pradhan, Shrabani; Das, Koushik; Nandi, Dilip Kumar

2013-01-01

Objective To investigate phytochemical screening, antimicrobial activity and qualitative thin layer chromatographic separation of flavonoid components, antioxidant activity and total flavonoid compound of Terminalia arjuna. Methods For phytochemical screening, some common and available standard tests were done. Antimicrobial bioassay was done through agar well diffusion method. Detection of antioxidant activity and flavonoid compounds were done through thin layer chromatography. Total antioxidant activity was measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) in colorimetric method. Aluminum chloride colorimetric method was used for total flavonoid determination. Results Phytochemical screening showed the active compounds presence in high concentration, such as phytosterol, lactones, flavonoids, phenolic compounds and tannins and glycosides. The antimicrobial activity of extract showed that greater inhibition zone against Gram negative bacteria than Gram positive bacteria. This methanolic extract showed a promising antioxidant activity, as absorption of DPPH redicles decreased in DPPH free radical scavenging assay. Flavonoids components having antioxidant property present in the methanol extract at a level of 199.00 mg quercetin equivalent/g of dried methanol extract in colorimetric method. Conclusions The Terminalia arjuna bark extract revealed the presence of bio-active constituents which are known to exhibit medicinal as well as physiological activities. PMID:24093787

In silico identification of anti-cancer compounds and plants from traditional Chinese medicine database

NASA Astrophysics Data System (ADS)

Dai, Shao-Xing; Li, Wen-Xing; Han, Fei-Fei; Guo, Yi-Cheng; Zheng, Jun-Juan; Liu, Jia-Qian; Wang, Qian; Gao, Yue-Dong; Li, Gong-Hua; Huang, Jing-Fei

2016-05-01

There is a constant demand to develop new, effective, and affordable anti-cancer drugs. The traditional Chinese medicine (TCM) is a valuable and alternative resource for identifying novel anti-cancer agents. In this study, we aim to identify the anti-cancer compounds and plants from the TCM database by using cheminformatics. We first predicted 5278 anti-cancer compounds from TCM database. The top 346 compounds were highly potent active in the 60 cell lines test. Similarity analysis revealed that 75% of the 5278 compounds are highly similar to the approved anti-cancer drugs. Based on the predicted anti-cancer compounds, we identified 57 anti-cancer plants by activity enrichment. The identified plants are widely distributed in 46 genera and 28 families, which broadens the scope of the anti-cancer drug screening. Finally, we constructed a network of predicted anti-cancer plants and approved drugs based on the above results. The network highlighted the supportive role of the predicted plant in the development of anti-cancer drug and suggested different molecular anti-cancer mechanisms of the plants. Our study suggests that the predicted compounds and plants from TCM database offer an attractive starting point and a broader scope to mine for potential anti-cancer agents.

Cyclometalated Iminophosphorane Gold(III) and Platinum(II) Complexes. A Highly Permeable Cationic Platinum(II) Compound with Promising Anticancer Properties

PubMed Central

2015-01-01

New organometallic gold(III) and platinum(II) complexes containing iminophosphorane ligands are described. Most of them are more cytotoxic to a number of human cancer cell lines than cisplatin. Cationic Pt(II) derivatives 4 and 5, which differ only in the anion, Hg2Cl62– or PF6– respectively, display almost identical IC50 values in the sub-micromolar range (25–335-fold more active than cisplatin on these cell lines). The gold compounds induced mainly caspase-independent cell death, as previously reported for related cycloaurated compounds containing IM ligands. Cycloplatinated compounds 3, 4, and 5 can also activate alternative caspase-independent mechanisms of death. However, at short incubation times cell death seems to be mainly caspase dependent, suggesting that the main mechanism of cell death for these compounds is apoptosis. Mercury-free compound 5 does not interact with plasmid (pBR322) DNA or with calf thymus DNA. Permeability studies of 5 by two different assays, in vitro Caco-2 monolayers and a rat perfusion model, have revealed a high permeability profile for this compound (comparable to that of metoprolol or caffeine) and an estimated oral fraction absorbed of 100%, which potentially makes it a good candidate for oral administration. PMID:26147404

In silico identification of anti-cancer compounds and plants from traditional Chinese medicine database.

PubMed

Dai, Shao-Xing; Li, Wen-Xing; Han, Fei-Fei; Guo, Yi-Cheng; Zheng, Jun-Juan; Liu, Jia-Qian; Wang, Qian; Gao, Yue-Dong; Li, Gong-Hua; Huang, Jing-Fei

2016-05-05

There is a constant demand to develop new, effective, and affordable anti-cancer drugs. The traditional Chinese medicine (TCM) is a valuable and alternative resource for identifying novel anti-cancer agents. In this study, we aim to identify the anti-cancer compounds and plants from the TCM database by using cheminformatics. We first predicted 5278 anti-cancer compounds from TCM database. The top 346 compounds were highly potent active in the 60 cell lines test. Similarity analysis revealed that 75% of the 5278 compounds are highly similar to the approved anti-cancer drugs. Based on the predicted anti-cancer compounds, we identified 57 anti-cancer plants by activity enrichment. The identified plants are widely distributed in 46 genera and 28 families, which broadens the scope of the anti-cancer drug screening. Finally, we constructed a network of predicted anti-cancer plants and approved drugs based on the above results. The network highlighted the supportive role of the predicted plant in the development of anti-cancer drug and suggested different molecular anti-cancer mechanisms of the plants. Our study suggests that the predicted compounds and plants from TCM database offer an attractive starting point and a broader scope to mine for potential anti-cancer agents.

In silico identification of anti-cancer compounds and plants from traditional Chinese medicine database

PubMed Central

Dai, Shao-Xing; Li, Wen-Xing; Han, Fei-Fei; Guo, Yi-Cheng; Zheng, Jun-Juan; Liu, Jia-Qian; Wang, Qian; Gao, Yue-Dong; Li, Gong-Hua; Huang, Jing-Fei

2016-01-01

There is a constant demand to develop new, effective, and affordable anti-cancer drugs. The traditional Chinese medicine (TCM) is a valuable and alternative resource for identifying novel anti-cancer agents. In this study, we aim to identify the anti-cancer compounds and plants from the TCM database by using cheminformatics. We first predicted 5278 anti-cancer compounds from TCM database. The top 346 compounds were highly potent active in the 60 cell lines test. Similarity analysis revealed that 75% of the 5278 compounds are highly similar to the approved anti-cancer drugs. Based on the predicted anti-cancer compounds, we identified 57 anti-cancer plants by activity enrichment. The identified plants are widely distributed in 46 genera and 28 families, which broadens the scope of the anti-cancer drug screening. Finally, we constructed a network of predicted anti-cancer plants and approved drugs based on the above results. The network highlighted the supportive role of the predicted plant in the development of anti-cancer drug and suggested different molecular anti-cancer mechanisms of the plants. Our study suggests that the predicted compounds and plants from TCM database offer an attractive starting point and a broader scope to mine for potential anti-cancer agents. PMID:27145869

Novel urea and bis-urea primaquine derivatives with hydroxyphenyl or halogenphenyl substituents: Synthesis and biological evaluation.

PubMed

Perković, I; Antunović, M; Marijanović, I; Pavić, K; Ester, K; Kralj, M; Vlainić, J; Kosalec, I; Schols, D; Hadjipavlou-Litina, D; Pontiki, E; Zorc, B

2016-11-29

A series of novel compounds 3a-j and 6a-j with primaquine and hydroxyl or halogen substituted benzene moieties bridged by urea or bis-urea functionalities were designed, synthesized and evaluated for biological activity. The title compounds were prepared using benzotriazole as the synthon, through several synthetic steps. 3-[3,5-Bis(trifluoromethyl)phenyl]-1-{4-[(6-methoxyquinolin-8-yl)amino]pentyl}urea (3j) was the most active urea and 1-[({4-[(6-methoxyquinolin-8-yl)amino]pentyl}carbamoyl)amino]-3-[3-(trifluoromethyl)phenyl]urea (6h) the most active bis-urea derivative in antiproliferative screening in vitro against eight tested cancer cell lines. Urea derivatives 3a-g with hydroxy group or one halogen atom showed moderate antiproliferative effects against all the tested cell lines, but stronger activity against breast carcinoma MCF-7 cell line, while trifluoromethyl derivatives 3h-j showed antiproliferative effects against all the tested cell lines in low micromolar range. Finally, bis-ureas with hydroxy and fluoro substituents 6a-d showed extreme selectivity and chloro or bromo derivatives 6e-g high selectivity against MCF-7 cells (IC 50 0.1-2.6 μM). p-Fluoro derivative 6d, namely 3-(4-fluorophenyl)-1-[({4-[(6-methoxyquinolin-8-yl)amino]pentyl}carbamoyl)amino]urea, is the most promising compound. Further biological experiments showed that 6d affected cell cycle and induced cell death of MCF-7 cell line. Due to its high activity against MCF-7 cell line (IC 50 0.31 μM), extreme selectivity and full agreement with the Lipinski's and Gelovani's rules for prospective small molecular drugs, 6d may be considered as a lead compound in development of breast carcinoma drugs. Urea 3b and almost all bis-ureas showed high antioxidant activity in DPPH assay, but urea derivatives were more active in lipid peroxidation test. Only few compounds exhibited weak inhibition of soybean lipoxygenase. Compound 3j exhibited the strongest antimicrobial activity in susceptibility assay in vitro (MIC = 1.6-12.5 μg ml -1 ). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Investigation on Quantitative Structure Activity Relationships of a Series of Inducible Nitric Oxide.

PubMed

Sharma, Mukesh C; Sharma, S

2016-12-01

A series of 2-dihydro-4-quinazolin with potent highly selective inhibitors of inducible nitric oxide synthase activities was subjected to quantitative structure activity relationships (QSAR) analysis. Statistically significant equations with high correlation coefficient (r 2  = 0.8219) were developed. The k-nearest neighbor model has showed good cross-validated correlation coefficient and external validation values of 0.7866 and 0.7133, respectively. The selected electrostatic field descriptors the presence of blue ball around R1 and R4 in the quinazolinamine moiety showed electronegative groups favorable for nitric oxide synthase activity. The QSAR models may lead to the structural requirements of inducible nitric oxide compounds and help in the design of new compounds.

Exploratory Characterization of Phenolic Compounds with Demonstrated Anti-Diabetic Activity in Guava Leaves at Different Oxidation States

PubMed Central

Díaz-de-Cerio, Elixabet; Verardo, Vito; Gómez-Caravaca, Ana María; Fernández-Gutiérrez, Alberto; Segura-Carretero, Antonio

2016-01-01

Psidium guajava L. is widely used like food and in folk medicine all around the world. Many studies have demonstrated that guava leaves have anti-hyperglycemic and anti-hyperlipidemic activities, among others, and that these activities belong mainly to phenolic compounds, although it is known that phenolic composition in guava tree varies throughout seasonal changes. Andalusia is one of the regions in Europe where guava is grown, thus, the aim of this work was to study the phenolic compounds present in Andalusian guava leaves at different oxidation states (low, medium, and high). The phenolic compounds in guava leaves were determined by HPLC-DAD-ESI-QTOF-MS. The results obtained by chromatographic analysis reported that guava leaves with low degree of oxidation had a higher content of flavonols, gallic, and ellagic derivatives compared to the other two guava leaf samples. Contrary, high oxidation state guava leaves reported the highest content of cyanidin-glucoside that was 2.6 and 15 times higher than guava leaves with medium and low oxidation state, respectively. The QTOF platform permitted the determination of several phenolic compounds with anti-diabetic properties and provided new information about guava leaf phenolic composition that could be useful for nutraceutical production. PMID:27187352

Exploratory Characterization of Phenolic Compounds with Demonstrated Anti-Diabetic Activity in Guava Leaves at Different Oxidation States.

PubMed

Díaz-de-Cerio, Elixabet; Verardo, Vito; Gómez-Caravaca, Ana María; Fernández-Gutiérrez, Alberto; Segura-Carretero, Antonio

2016-05-11

Psidium guajava L. is widely used like food and in folk medicine all around the world. Many studies have demonstrated that guava leaves have anti-hyperglycemic and anti-hyperlipidemic activities, among others, and that these activities belong mainly to phenolic compounds, although it is known that phenolic composition in guava tree varies throughout seasonal changes. Andalusia is one of the regions in Europe where guava is grown, thus, the aim of this work was to study the phenolic compounds present in Andalusian guava leaves at different oxidation states (low, medium, and high). The phenolic compounds in guava leaves were determined by HPLC-DAD-ESI-QTOF-MS. The results obtained by chromatographic analysis reported that guava leaves with low degree of oxidation had a higher content of flavonols, gallic, and ellagic derivatives compared to the other two guava leaf samples. Contrary, high oxidation state guava leaves reported the highest content of cyanidin-glucoside that was 2.6 and 15 times higher than guava leaves with medium and low oxidation state, respectively. The QTOF platform permitted the determination of several phenolic compounds with anti-diabetic properties and provided new information about guava leaf phenolic composition that could be useful for nutraceutical production.

[Molecular design of anti-MRSA drugs].

PubMed

Hanaki, H

1997-05-01

The true nature of resistance of methicillin-resistant Staphylococcus aureus (MRSA) is penicillin-binding protein 2' (PBP2'). Affinities of almost all beta-lactam antibiotics to PBP2' were very low. Therefore, MRSA which produces PBP2' shows resistance to all beta-lactam antibiotics. However, PBP2' has a different affinity to each beta-lactam antibiotic. For this reason, we thought that some derivatives of beta-lactam compounds could have high affinity to PBP2'. Accordingly, we developed cephem compounds which are more stabile and safe than previous penicillin and carbapenem compounds. Firstly, we investigated the side chain at C-7 position on 2-thioisocephem skeletal. Hydroxyimino-aminothiazol at C-7 position on 2-thioisocephem skeletal had the strongest activity against MRSA. Secondly, we investigated the linkage styles at C-3 position on 2-thioisocephem skeletal which were methylene, vinyl, and propylene. The compound of vinyl linkage style at C-3 position on 2-thioisocephem skeletal showed high activity against MRSA. Finally, we investigated 1-thiocephem, 2-thioisocephem, and 2-oxaisocephem as cephem-skeletals. Simultaneously, we studied C-3 linkage styles which were methylene, vinyl, and propylene. From these results, we found out that the compound of hydroxyiminoaminothiazol at C-7 position and vinyl linkage style at C-3 position on 1-thiocephem skeletal has superb activity against MRSA.

Penialidins A-C with strong antibacterial activities from Penicillium sp., an endophytic fungus harboring leaves of Garcinia nobilis.

PubMed

Jouda, Jean-Bosco; Kusari, Souvik; Lamshöft, Marc; Mouafo Talontsi, Ferdinand; Douala Meli, Clovis; Wandji, Jean; Spiteller, Michael

2014-10-01

Three new polyketides named penialidins A-C (1-3), along with one known compound, citromycetin (4), were isolated from an endophytic fungus, Penicillium sp., harbored in the leaves of the Cameroonian medicinal plant Garcinia nobilis. Their structures were elucidated by means of spectroscopic and spectrometric methods (NMR and HRMS(n)). The antibacterial efficacies of the new compounds (1-3) were tested against the clinically-important risk group 2 (RG2) bacterial strains of Staphylococcus aureus and Escherichia coli. The ecologically imposing strains of E. coli (RG1), Bacillus subtilis and Acinetobacter sp. BD4 were also included in the assay. Compound 3 exhibited pronounced activity against the clinically-relevant S. aureus as well as against B. subtilis comparable to that of the reference standard (streptomycin). Compound 2 was also highly-active against S. aureus. By comparing the structures of the three new compounds (1-3), it was revealed that altering the substitutions at C-10 and C-2 can significantly increase the antibacterial activity of 1. Copyright © 2014 Elsevier B.V. All rights reserved.

The in-vitro anti-leishmanial activity of inhibitors of ergosterol biosynthesis.

PubMed

Gebre-Hiwot, A; Frommel, D

1993-12-01

The in-vitro activity of a group of antifungal compounds known to inhibit ergosterol synthesis was investigated against Leishmania donovani grown as intracellular amastigotes in the human leukaemia monocyte cell line, THP-1. Toxicity on the host cells was assessed using the colorimetric MTT assay. Compounds inhibiting 2,3 oxidosqualene lanosterol cyclase; RO 43-3815, RO 43-5955, RO 43-8208, RO 42-6589 and RO 43-0688 displayed high activity with a median effective dose (ED50) of 0.6, 0.9, 3.5, 2.2 and 0.7 mg/L respectively. Of the azole compounds, oxiconazole had an ED50 value of 3.3 mg/L while ketoconazole showed the least activity. The delta-14-reductase and delta-8-delta-7 isomerase inhibitor, amorolfine, gave the highest therapeutic index with an ED50 value of 1.6 mg/L. Most compounds tested had a lower ED50 value than the standard antileishmanial drugs, sodium stibogluconate (5.5 mg Sbv/L) and meglumine antimoniate (3.0 mg Sbv/L) indicating the clean potential of these antifungal compounds in treating leishmaniasis.

Combinatorial Libraries As a Tool for the Discovery of Novel, Broad-Spectrum Antibacterial Agents Targeting the ESKAPE Pathogens.

PubMed

Fleeman, Renee; LaVoi, Travis M; Santos, Radleigh G; Morales, Angela; Nefzi, Adel; Welmaker, Gregory S; Medina-Franco, José L; Giulianotti, Marc A; Houghten, Richard A; Shaw, Lindsey N

2015-04-23

Mixture based synthetic combinatorial libraries offer a tremendous enhancement for the rate of drug discovery, allowing the activity of millions of compounds to be assessed through the testing of exponentially fewer samples. In this study, we used a scaffold-ranking library to screen 37 different libraries for antibacterial activity against the ESKAPE pathogens. Each library contained between 10000 and 750000 structural analogues for a total of >6 million compounds. From this, we identified a bis-cyclic guanidine library that displayed strong antibacterial activity. A positional scanning library for these compounds was developed and used to identify the most effective functional groups at each variant position. Individual compounds were synthesized that were broadly active against all ESKAPE organisms at concentrations <2 μM. In addition, these compounds were bactericidal, had antibiofilm effects, showed limited potential for the development of resistance, and displayed almost no toxicity when tested against human lung cells and erythrocytes. Using a murine model of peritonitis, we also demonstrate that these agents are highly efficacious in vivo.

Small-molecule inhibitors of phosphatidylcholine transfer protein/StarD2 identified by high-throughput screening.

PubMed

Wagle, Neil; Xian, Jun; Shishova, Ekaterina Y; Wei, Jie; Glicksman, Marcie A; Cuny, Gregory D; Stein, Ross L; Cohen, David E

2008-12-01

Phosphatidylcholine transfer protein (PC-TP, also referred to as StarD2) is a highly specific intracellular lipid-binding protein that catalyzes the transfer of phosphatidylcholines between membranes in vitro. Recent studies have suggested that PC-TP in vivo functions to regulate fatty acid and glucose metabolism, possibly via interactions with selected other proteins. To begin to address the relationship between activity in vitro and biological function, we undertook a high-throughput screen to identify small-molecule inhibitors of the phosphatidylcholine transfer activity of PC-TP. After adapting a fluorescence quench assay to measure phosphatidylcholine transfer activity, we screened 114,752 compounds of a small-molecule library. The high-throughput screen identified 14 potential PC-TP inhibitors. Of these, 6 compounds exhibited characteristics consistent with specific inhibition of PC-TP activity, with IC(50) values that ranged from 4.1 to 95.0muM under conditions of the in vitro assay. These compounds should serve as valuable reagents to elucidate the biological function of PC-TP. Because mice with homozygous disruption of the PC-TP gene (Pctp) are sensitized to insulin action and relatively resistant to the development of atherosclerosis, these inhibitors may also prove to be of value in the management of diabetes and atherosclerotic cardiovascular diseases.

Plantago maxima leaves extract inhibits adipogenic action of a high-fat diet in female Wistar rats.

PubMed

Tinkov, Alexey A; Nemereshina, Olga N; Popova, Elizaveta V; Polyakova, Valentina S; Gritsenko, Viktor A; Nikonorov, Alexandr A

2014-04-01

The primary objective of this study is to investigate the content of biologically active compounds producing an antioxidant effect in Plantago maxima and their influence on main mechanisms of dietary obesity development. Biologically active compounds in P. maxima were tested using paper chromatography. In in vivo experiment, high-fat-fed Wistar rats obtained P. maxima water extract for 3 months. Morphometric parameters, weight gain, serum adipokines, and cytokines, as well as oxidative stress biomarkers in rats’ tissues were evaluated. Gut microflora was also examined. Plantago maxima leaves used in the experiment contained significant amount of flavonoids, iridoids, phenol carboxylic acids, and tannins and ascorbic acid. Our in vivo experiment data demonstrate that P. maxima water extract prevents excessive adiposity in a diet-induced model. P. maxima consumption reduced serum leptin (twofold), macrophage chemoattractant protein-1 (sevenfold), tumornecrosis factor-α (25%), and interleukine-6 (26%) levels. P. maxima water extract decreased adipose tissue oxidative stress biomarkers in rats fed a high-fat diet. In addition, increased bacterial growth in the diet-induced obesity model was reversed by the P. maxima extract treatment. Plantago maxima water extract possessed antiadipogenic, antidiabetic, antiinflammatory, antioxidant activity, and normalized gut microflora in a rat model of diet-induced excessive adiposity due to a high content of biologically active compounds.

Comparative studies of bioactive organosulphur compounds and antioxidant activities in garlic (Allium sativum L.), elephant garlic (Allium ampeloprasum L.) and onion (Allium cepa L.).

PubMed

Kim, Sunyoung; Kim, Dan-Bi; Jin, Wenjie; Park, Junghyuck; Yoon, Wonjin; Lee, Yunyeol; Kim, Soyoung; Lee, Sanghee; Kim, Sungsoo; Lee, Ok-Hwan; Shin, Dongbin; Yoo, Miyoung

2018-05-01

We evaluated organosulphur compounds in Allium vegetables, including garlic, elephant garlic and onion, using high-performance liquid chromatography. Among organosulphur compounds, elephant garlic had considerable γ-glutamyl peptides, and garlic had the highest alliin content. Onion had low level of organosulphur compounds than did elephant garlic and garlic. In addition, antioxidant capacities were evaluated by oxygen radical absorbance capacity (ORAC) values and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay. The results showed that garlic had the highest antioxidant capacity, followed by elephant garlic and onion. Furthermore, a positive correlation was observed between antioxidant activities and organosulphur compounds (R > 0.77). Therefore, our results indicate that there was a close relationship between antioxidant capacity and organosulphur compounds in Allium vegetables.

Relative contributions of active mediated transport and passive diffusion of fluoroquinolones with various lipophilicities in a Calu-3 lung epithelial cell model.

PubMed

Brillault, Julien; De Castro, Whocely Victor; Couet, William

2010-01-01

The transport characteristics of six fluoroquinolones (FQs) with various lipophilicities were compared in a Calu-3 cell model. For each FQ, an active polarized transport was observed in the direction of the apical side. However, the apparent permeability of FQs resulted from active transport and passive diffusion that were highly variable between compounds and mainly governed by lipophilicity. Therefore, active transport was predominant for compounds with relatively low lipophilicity but minor for FQs with higher lipophilicity.

Two High Throughput Screen Assays for Measurement of TNF-α in THP-1 Cells

PubMed Central

Leister, Kristin P; Huang, Ruili; Goodwin, Bonnie L; Chen, Andrew; Austin, Christopher P; Xia, Menghang

2011-01-01

Tumor Necrosis Factor-α (TNF-α), a secreted cytokine, plays an important role in inflammatory diseases and immune disorders, and is a potential target for drug development. The traditional assays for detecting TNF-α, enzyme linked immunosorbent assay (ELISA) and radioimmunoassay, are not suitable for the large size compound screens. Both assays suffer from a complicated protocol, multiple plate wash steps and/or excessive radioactive waste. A simple and quick measurement of TNF-α production in a cell based assay is needed for high throughput screening to identify the lead compounds from the compound library. We have developed and optimized two homogeneous TNF-α assays using the HTRF (homogeneous time resolved fluorescence) and AlphaLISA assay formats. We have validated the HTRF based TNF-α assay in a 1536-well plate format by screening a library of 1280 pharmacologically active compounds. The active compounds identified from the screen were confirmed in the AlphaLISA TNF-α assay using a bead-based technology. These compounds were also confirmed in a traditional ELISA assay. From this study, several beta adrenergic agonists have been identified as TNF-α inhibitors. We also identified several novel inhibitors of TNF-α, such as BTO-1, CCG-2046, ellipticine, and PD 169316. The results demonstrated that both homogeneous TNF-α assays are robust and suitable for high throughput screening. PMID:21643507

Purification and characterization of two new cell-bound bioactive compounds produced by wild Lactococcus lactis strain.

PubMed

Saraiva, Margarete Alice Fontes; Brede, Dag Anders; Nes, Ingolf Figved; Baracat-Pereira, Maria Cristina; de Queiroz, Marisa Vieira; de Moraes, Célia Alencar

2017-07-03

Novel compounds and innovative methods are required considering that antibiotic resistance has reached a crisis point. In the study, two cell-bound antimicrobial compounds produced by Lactococcus lactis ID1.5 were isolated and partially characterized. Following purification by cationic exchange and a solid-phase C18 column, antimicrobial activity was recovered after three runs of RPC using 60% (v/v) and 100% (v/v) of 2-propanol for elution, suggesting that more than one antimicrobial compound were produced by L. lactis ID1.5, which were in this study called compounds AI and AII. The mass spectrum of AI and AII showed major intensity ions at m/z 1070.05 and 955.9 Da, respectively. The compound AI showed a spectrum of antimicrobial activity mainly against L. lactis species, while the organisms most sensitive to compound AII were Bacillus subtilis, Listeria innocua, Streptococcus pneumoniae and Pseudomonas aeruginosa. The antimicrobial activity of both compounds was suppressed by treatment with Tween 80. Nevertheless, both compounds showed high stability to heat and proteases treatments. The isolated compounds, AI and AII, showed distinct properties from other antimicrobial substances already reported as produced by L. lactis, and have a significant inhibitory effect against two clinically important respiratory pathogens. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Design, synthesis, antiviral activity and three-dimensional quantitative structure-activity relationship study of novel 1,4-pentadien-3-one derivatives containing the 1,3,4-oxadiazole moiety.

PubMed

Gan, Xiuhai; Hu, Deyu; Li, Pei; Wu, Jian; Chen, Xuewen; Xue, Wei; Song, Baoan

2016-03-01

1,4-Pentadien-3-one and 1,3,4-oxadiazole derivatives possess good antiviral activities, and their substructure units are usually used in antiviral agent design. In order to discover novel molecules with high antiviral activities, a series of 1,4-pentadien-3-one derivatives containing the 1,3,4-oxadiazole moiety were designed and synthesised. Bioassays showed that most of the title compounds exhibited good inhibitory activities against tobacco mosaic virus (TMV) in vivo. The compound 8f possessing the best protective activity against TMV had an EC50 value of 135.56 mg L(-1) , which was superior to that of ribavirin (435.99 mg L(-1) ). Comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) techniques were used in three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of protective activities, with values of q(2) and r(2) for the CoMFA and CoMSIA models of 0.751 and 0.775 and 0.936 and 0.925 respectively. Compound 8k with higher protective activity (EC50 = 123.53 mg L(-1) ) according to bioassay was designed and synthesised on the basis of the 3D-QSAR models. Some of the title compounds displayed good antiviral activities. 3D-QSAR models revealed that the appropriate compact electron-withdrawing and hydrophobic group at the benzene ring could enhance antiviral activity. These results could provide important structural insights for the design of highly active 1,4-pentadien-3-one derivatives. © 2015 Society of Chemical Industry.

Synthesis and antitumoral activity of novel 3-(2-substituted-1,3,4-oxadiazol-5-yl) and 3-(5-substituted-1,2,4-triazol-3-yl) beta-carboline derivatives.

PubMed

Formagio, Anelise S Nazari; Tonin, Lilian T Düsman; Foglio, Mary Ann; Madjarof, Christiana; de Carvalho, João Ernesto; da Costa, Willian Ferreira; Cardoso, Flávia P; Sarragiotto, Maria Helena

2008-11-15

Several novel 1-substituted-phenyl beta-carbolines bearing the 2-substituted-1,3,4-oxadiazol-5-yl and 5-substituted-1,2,4-triazol-3-yl groups at C-3 were synthesized and evaluated for their in vitro anticancer activity. The assay results pointed thirteen compounds with growth inhibition effect (GI(50)<100 microM) for all eight different types of human cancer cell lines tested. The beta-carbolines 7a and 7h, bearing the 3-(2-metylthio-1,3,4-oxadiazol-5-yl) group, displayed high selectivity and potent anticancer activity against ovarian cell line with GI(50) values lying in the nanomolar concentration range (GI(50)=10 nM for both compounds). The 1-(N,N-dimethylaminophenyl)-3-(5-thioxo-1,2,4-triazol-3-yl) beta-carboline (8g) was the most active compound, showing particular effectiveness on lung (GI(50)=0.06 microM), ovarian and renal cell lines. The potent anticancer activity presented for synthesized compounds 7a, 7h, and 8g, together with their easiness of synthesis, makes these compounds promising anticancer agents.

Nonaminoglycoside compounds induce readthrough of nonsense mutations

PubMed Central

Damoiseaux, Robert; Nahas, Shareef; Gao, Kun; Hu, Hailiang; Pollard, Julianne M.; Goldstine, Jimena; Jung, Michael E.; Henning, Susanne M.; Bertoni, Carmen

2009-01-01

Large numbers of genetic disorders are caused by nonsense mutations for which compound-induced readthrough of premature termination codons (PTCs) might be exploited as a potential treatment strategy. We have successfully developed a sensitive and quantitative high-throughput screening (HTS) assay, protein transcription/translation (PTT)–enzyme-linked immunosorbent assay (ELISA), for identifying novel PTC-readthrough compounds using ataxia-telangiectasia (A-T) as a genetic disease model. This HTS PTT-ELISA assay is based on a coupled PTT that uses plasmid templates containing prototypic A-T mutated (ATM) mutations for HTS. The assay is luciferase independent. We screened ∼34,000 compounds and identified 12 low-molecular-mass nonaminoglycosides with potential PTC-readthrough activity. From these, two leading compounds consistently induced functional ATM protein in ATM-deficient cells containing disease-causing nonsense mutations, as demonstrated by direct measurement of ATM protein, restored ATM kinase activity, and colony survival assays for cellular radiosensitivity. The two compounds also demonstrated readthrough activity in mdx mouse myotube cells carrying a nonsense mutation and induced significant amounts of dystrophin protein. PMID:19770270

Inhibition of monoamine oxidase by derivatives of piperine, an alkaloid from the pepper plant Piper nigrum, for possible use in Parkinson's disease.

PubMed

Al-Baghdadi, Osamah B; Prater, Natalie I; Van der Schyf, Cornelis J; Geldenhuys, Werner J

2012-12-01

A series of compounds related to piperine and antiepilepsirine was screened in a monoamine oxidase A and B assay. Piperine is an alkaloid from the source plant of both black and white pepper grains, Piper nigrum. Piperine has been shown to have a wide range of activity, including MAO inhibitory activity. The z-factor for the screening assay was found to be greater than 0.8 for both assays. Notably, the compounds tested were selective towards MAO-B, with the most potent compound having an IC(50) of 498 nM. To estimate blood-brain barrier (BBB) permeability, we used a PAMPA assay, which suggested that the compounds are likely to penetrate the BBB. A fluorescent bovine serum albumin (BSA) high-throughput screening (HTS) binding assay showed an affinity of 8 μM for piperine, with more modest binding for other test compounds. Taken together, the data described here may be useful in gaining insight towards the design of selective MAO-B inhibitory compounds devoid of MAO-A activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Identification of marine neuroactive molecules in behaviour-based screens in the larval zebrafish.

PubMed

Long, Si-Mei; Liang, Feng-Yin; Wu, Qi; Lu, Xi-Lin; Yao, Xiao-Li; Li, Shi-Chang; Li, Jing; Su, Huanxing; Pang, Ji-Yan; Pei, Zhong

2014-05-30

High-throughput behavior-based screen in zebrafish is a powerful approach for the discovery of novel neuroactive small molecules for treatment of nervous system diseases such as epilepsy. To identify neuroactive small molecules, we first screened 36 compounds (1-36) derived from marine natural products xyloketals and marine isoprenyl phenyl ether obtained from the mangrove fungus. Compound 1 demonstrated the most potent inhibition on the locomotor activity in larval zebrafish. Compounds 37-42 were further synthesized and their potential anti-epilepsy action was then examined in a PTZ-induced epilepsy model in zebrafish. Compound 1 and compounds 39, 40 and 41 could significantly attenuate PTZ-induced locomotor hyperactivity and elevation of c-fos mRNA in larval zebrafish. Compound 40 showed the most potent inhibitory action against PTZ-induced hyperactivity. The structure-activity analysis showed that the OH group at 12-position played a critical role and the substituents at the 13-position were well tolerated in the inhibitory activity of xyloketal derivatives. Thus, these derivatives may provide some novel drug candidates for the treatment of epilepsy.

Activity ranking of synthetic analogs targeting vascular endothelial growth factor receptor 2 by an integrated cell membrane chromatography system.

PubMed

Wang, Dongyao; Lv, Diya; Chen, Xiaofei; Liu, Yue; Ding, Xuan; Jia, Dan; Chen, Langdong; Zhu, Zhenyu; Cao, Yan; Chai, Yifeng

2015-12-01

Evaluating the biological activities of small molecules represents an important part of the drug discovery process. Cell membrane chromatography (CMC) is a well-developed biological chromatographic technique. In this study, we have developed combined SMMC-7721/CMC and HepG2/CMC with high-performance liquid chromatography and time-of-flight mass spectrometry to establish an integrated screening platform. These systems was subsequently validated and used for evaluating the activity of quinazoline compounds, which were designed and synthesized to target vascular endothelial growth factor receptor 2. The inhibitory activities of these compounds towards this receptor were also tested using a classical caliper mobility shift assay. The results revealed a significant correlation between these two methods (R(2) = 0.9565 or 0.9420) for evaluating the activities of these compounds. Compared with traditional methods of evaluating the activities analogous compounds, this integrated cell membrane chromatography screening system took less time and was more cost effective, indicating that it could be used as a practical method in drug discovery. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of OASIS QSAR Models Using ToxCast™ in Vitro Estrogen and Androgen Receptor Binding Data and Application in an Integrated Endocrine Screening Approach

PubMed Central

Bhhatarai, Barun; Wilson, Daniel M.; Price, Paul S.; Marty, Sue; Parks, Amanda K.; Carney, Edward

2016-01-01

Background: Integrative testing strategies (ITSs) for potential endocrine activity can use tiered in silico and in vitro models. Each component of an ITS should be thoroughly assessed. Objectives: We used the data from three in vitro ToxCast™ binding assays to assess OASIS, a quantitative structure-activity relationship (QSAR) platform covering both estrogen receptor (ER) and androgen receptor (AR) binding. For stronger binders (described here as AC50 < 1 μM), we also examined the relationship of QSAR predictions of ER or AR binding to the results from 18 ER and 10 AR transactivation assays, 72 ER-binding reference compounds, and the in vivo uterotrophic assay. Methods: NovaScreen binding assay data for ER (human, bovine, and mouse) and AR (human, chimpanzee, and rat) were used to assess the sensitivity, specificity, concordance, and applicability domain of two OASIS QSAR models. The binding strength relative to the QSAR-predicted binding strength was examined for the ER data. The relationship of QSAR predictions of binding to transactivation- and pathway-based assays, as well as to in vivo uterotrophic responses, was examined. Results: The QSAR models had both high sensitivity (> 75%) and specificity (> 86%) for ER as well as both high sensitivity (92–100%) and specificity (70–81%) for AR. For compounds within the domains of the ER and AR QSAR models that bound with AC50 < 1 μM, the QSAR models accurately predicted the binding for the parent compounds. The parent compounds were active in all transactivation assays where metabolism was incorporated and, except for those compounds known to require metabolism to manifest activity, all assay platforms where metabolism was not incorporated. Compounds in-domain and predicted to bind by the ER QSAR model that were positive in ToxCast™ ER binding at AC50 < 1 μM were active in the uterotrophic assay. Conclusions: We used the extensive ToxCast™ HTS binding data set to show that OASIS ER and AR QSAR models had high sensitivity and specificity when compounds were in-domain of the models. Based on this research, we recommend a tiered screening approach wherein a) QSAR is used to identify compounds in-domain of the ER or AR binding models and predicted to bind; b) those compounds are screened in vitro to assess binding potency; and c) the stronger binders (AC50 < 1 μM) are screened in vivo. This scheme prioritizes compounds for integrative testing and risk assessment. Importantly, compounds that are not in-domain, that are predicted either not to bind or to bind weakly, that are not active in in vitro, that require metabolism to manifest activity, or for which in vivo AR testing is in order, need to be assessed differently. Citation: Bhhatarai B, Wilson DM, Price PS, Marty S, Parks AK, Carney E. 2016. Evaluation of OASIS QSAR models using ToxCast™ in vitro estrogen and androgen receptor binding data and application in an integrated endocrine screening approach. Environ Health Perspect 124:1453–1461; http://dx.doi.org/10.1289/EHP184 PMID:27152837

Antimicrobial and Antiradical Activity of Extracts Obtained from Leaves of Five Species of the Genus Bergenia: Identification of Antimicrobial Compounds.

PubMed

Żbikowska, Beata; Franiczek, Roman; Sowa, Alina; Połukord, Grażyna; Krzyżanowska, Barbara; Sroka, Zbigniew

2017-09-01

An important focus of modern medicine is the search for new substances and strategies to combat infectious diseases, which present an increasing threat due to the growth of bacterial resistance to antibiotics. Another problem concerns free radicals, which in excess can cause several serious diseases. An alternative to chemical synthesis of antimicrobial and antiradical compounds is to find active substances in plant raw materials. We prepared extracts from leaves of five species of the genus Bergenia: B. purpurascens, B. cordifolia, B. ligulata, B. crassifolia, and B. ciliata. Antimicrobial and antiradical features of extracts and raw materials were assessed, and the quantities of phenolic compounds were determined. We also evaluated, using high-performance liquid chromatography, the amounts of arbutin and hydroquinone, compounds related to antimicrobial activity of these raw materials. The strongest antiradical properties were shown by leaves of B. crassifolia and B. cordifolia, the lowest by leaves of B. ciliata. The antiradical activity of extracts showed a strong positive correlation with the amount of phenols. All raw materials have significant antimicrobial properties. Among them, the ethyl acetate extracts were the most active. Antimicrobial activity very weakly correlated with the amount of arbutin, but correlated very strongly with the contents of both hydroquinone and phenolic compounds. Additional experiments using artificially prepared mixtures of phenolic compounds and hydroquinone allowed us to conclude that the most active antimicrobial substance is hydroquinone.

A high throughput screen identifies benzoquinoline compounds as inhibitors of Ebola virus replication.

PubMed

Luthra, Priya; Liang, Jue; Pietzsch, Colette A; Khadka, Sudip; Edwards, Megan R; Wei, Shuguang; De, Sampriti; Posner, Bruce; Bukreyev, Alexander; Ready, Joseph M; Basler, Christopher F

2018-02-01

Ebola virus (EBOV) is an enveloped negative-sense, single-stranded RNA virus of the filovirus family that causes severe disease in humans. Approved therapies for EBOV disease are lacking. EBOV RNA synthesis is carried out by a virus-encoded complex with RNA-dependent RNA polymerase activity that is required for viral propagation. This complex and its activities are therefore potential antiviral targets. To identify potential lead inhibitors of EBOV RNA synthesis, a library of small molecule compounds was screened against a previously established assay of EBOV RNA synthesis, the EBOV minigenome assay (MGA), in 384 well microplate format. The screen identified 56 hits that inhibited EBOV MGA activity by more than 70% while exhibiting less than 20% cell cytotoxicity. Inhibitory chemical scaffolds included angelicin derivatives, derivatives of the antiviral compound GSK983 and benzoquinolines. Structure-activity relationship (SAR) studies of the benzoquinoline scaffold produced ∼50 analogs and led to identification of an optimized compound, SW456, with a submicromolar IC 50 in the EBOV MGA and antiviral activity against infectious EBOV in cell culture. The compound was also active against a MGA for another deadly filovirus, Marburg virus. It also exhibited antiviral activity towards a negative-sense RNA virus from the rhabdovirus family, vesicular stomatitis virus, and a positive-sense RNA virus, Zika virus. Overall, these data demonstrate the potential of the EBOV MGA to identify anti-EBOV compounds and identifies the benzoquinoline series as a broad-spectrum antiviral lead. Copyright © 2017. Published by Elsevier B.V.

The synthesis and antistaphylococcal activity of 9, 13-disubstituted berberine derivatives.

PubMed

Wang, Jing; Yang, Teng; Chen, Huang; Xu, Yun-Nan; Yu, Li-Fang; Liu, Ting; Tang, Jie; Yi, Zhengfang; Yang, Cai-Guang; Xue, Wei; Yang, Fan

2017-02-15

A series of novel 9, 13-disubstituted berberine derivatives have been synthesized and evaluated for the antibacterial activities against Staphylococcus aureus, including Newman strain and multidrug-resistant strains (NRS-1, NRS-70, NRS-100, NRS-108, and NRS-271). Compound 20 shows the most potent activity against the growth of Newman strain, with a MIC value of 0.78 μg/mL, which is comparable with the positive control vancomycin. In addition, compound 20, 21, and 33 are highly antistaphylococcal active against five strains of multidrug-resistant S. aureus, with MIC values of 0.78-1.56 μg/mL. Of note, theses antibacterial active compounds have no obvious toxicity to the viability of human fibroblast (HAF) cells at the MIC concentration. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Bioactive Hydantoin Alkaloids from the Red Sea Marine Sponge Hemimycale arabica.

PubMed

Youssef, Diaa T A; Shaala, Lamiaa A; Alshali, Khalid Z

2015-10-28

In the course of our continuing efforts to identify bioactive secondary metabolites from Red Sea marine invertebrates, we have investigated the sponge Hemimycale arabica. The antimicrobial fraction of an organic extract of the sponge afforded two new hydantoin alkaloids, hemimycalins A and B (2 and 3), together with the previously reported compound (Z)-5-(4-hydroxybenzylidene)imidazolidine-2,4-dione (1). The structures of the compounds were determined by extensive 1D and 2D NMR (COSY, HSQC and HMBC) studies and high-resolution mass spectral determinations. Hemimycalins A (2) and B (3) represent the first examples of the natural N-alkylated hydantoins from the sponge Hemimycale arabica. Compounds 1-3 displayed variable antimicrobial activities against E. coli, S. aureus, and C. albicans. In addition, compound 1 displayed moderate antiproliferative activity against the human cervical carcinoma (HeLa) cell line. These findings provide further insight into the chemical diversity as well as the biological activity of this class of compounds.

Pyrrole-Based Antitubulin Agents: Two Distinct Binding Modalities Are Predicted for C-2 Analogues in the Colchicine Site

PubMed Central

2011-01-01

3,5-Dibromo-4-(3,4-dimethoxyphenyl)-1H-pyrrole-2-carboxylic acid ethyl ester is a promising antitubulin lead agent that targets the colchicine site of tubulin. C-2 analogues were synthesized and tested for microtubule depolymerizing and antiproliferative activity. Molecular modeling studies using both GOLD docking and HINT (Hydropathic INTeraction) scoring revealed two distinct binding modes that explain the structure–activity relationships and are in accord with the structural basis of colchicine binding to tubulin. The binding mode of higher activity compounds is buried deeper in the site and overlaps well with rings A and C of colchicine, while the lower activity binding mode shows fewer critical contacts with tubulin. The model distinguishes highly active compounds from those with weaker activities and provides novel insights into the colchicine site and compound design. PMID:22611477

Pyrrole-Based Antitubulin Agents: Two Distinct Binding Modalities are Predicted for C-2 Analogs in the Colchicine Site.

PubMed

Da, Chenxiao; Telang, Nakul; Barelli, Peter; Jia, Xin; Gupton, John T; Mooberry, Susan L; Kellogg, Glen E

2012-01-12

3,5-dibromo-4-(3,4-dimethoxyphenyl)-1H-pyrrole-2-carboxylic acid ethyl ester is a promising antitubulin lead agent that targets the colchicine site of tubulin. C-2 analogs were synthesized and tested for microtubule depolymerizing and antiproliferative activity. Molecular modeling studies using both GOLD docking and HINT (Hydropathic INTeraction) scoring revealed two distinct binding modes that explain the structural-activity relationships and are in accord with the structural basis of colchicine binding to tubulin. The binding mode of higher activity compounds is buried deeper in the site and overlaps well with rings A and C of colchicine, while the lower activity binding mode shows fewer critical contacts with tubulin. The model distinguishes highly active compounds from those with weaker activities and provides novel insights into the colchicine site and compound design.

Analysis and occurrence of endocrine-disrupting compounds and estrogenic activity in the surface waters of Central Spain.

PubMed

Esteban, S; Gorga, M; Petrovic, M; González-Alonso, S; Barceló, D; Valcárcel, Y

2014-01-01

Endocrine-disrupting compounds (EDCs) are chemical compounds with the ability to alter the hormonal systems of organisms. Such compounds are used in several industrial and domestic activities and reach the aquatic environment via wastewater discharge. The aim of this study is to assess the occurrence of 30 EDCs and related compounds in the surface waters of central Spain and to determine the overall estrogenic activity of environmental samples. This study analyzed a large number of EDCs and other emergent or suspected compounds with endocrine-disrupting activity. The results have shown the presence of 19 EDCs at concentrations ranging from 2 to 5928 ng L(-1). Organophosphorus-based flame retardants, alkylphenolic compounds and anticorrosives were found at the highest concentrations. Furthermore, although insufficient data are available to calculate an average over time, these preliminary results show the need to monitor the waters in both rivers studied. Alkylphenolic compounds, particularly nonylphenol, were the main contributors to overall estrogenicity. A higher concentration of the compounds studied was detected in the river Jarama, although the estrogenicity expressed as estradiol equivalents (EEQs) was higher in the river Manzanares due to a higher concentration of nonylphenol. However, the total estrogenicity did not exceed 1 ng L(-1) (EEQ), which is the level that may cause estrogenic effects in aquatic organisms, in any of the samples. In conclusion, the potential estrogenic risk in both rivers is low, although organophosphorus-based flame retardants may increase this risk as they were found at high levels in all samples. Unfortunately, these compounds could not be taken into account when calculating the estrogenic activity due to the lack of activity data for them. For future investigations, it will be important to assess the estrogenicity provided by these flame retardants. Due to the significant concentrations of EDCs detected in both rivers, further studies in this region are required. © 2013.

Identification and evaluation of magnolol and chrysophanol as the principle protein tyrosine phosphatase-1B inhibitory compounds in a Kampo medicine, Masiningan.

PubMed

Onoda, Toshihisa; Li, Wei; Sasaki, Tatsunori; Miyake, Megumi; Higai, Koji; Koike, Kazuo

2016-06-20

Masiningan is a traditional medicine consisting of six crude drugs that have been used for treating constipation and diabetes mellitus in both Japan and China. Masiningan has been reported to have significant PTP1B inhibitory activity and to affect cells in the insulin-signaling pathway. The aim of the present study is to identify the PTP1B inhibitory compounds in Masiningan. Bioactivity peaks were identified by analytical HPLC profiling and PTP1B inhibitory activity profiling of sub-fractions from Masiningan extract. The bioactive compounds were isolated by tracking two identified bioactive peaks, and the chemical structures were determined by spectroscopic analyses. The bioactive compounds were further investigated for their inhibitory effect against PTP1B by enzymatic kinetic analysis, molecular docking simulation, inhibitory selectivity against other PTPs, and cellular activity in the insulin signal transduction pathway. From Masiningan, magnolol (1) and chrysophanol (2) were isolated as compounds that exhibited significant dose-dependent inhibitory activities against PTP1B, with IC50 values of 24.6 and 12.3μM, respectively. Kinetic analysis revealed that 1 is a non-competitive and that 2 is a competitive PTP1B inhibitor. In the molecular docking simulation, compound 2 was stably positioned in the active pocket of PTP1B, and the CDOCKER energy was calculated to be 24.3411kcal/mol. Both compounds demonstrated remarkably high selectivity against four PTPs and revealed cellular activity against the insulin signal transduction pathway. Magnolol (1) and chrysophanol (2) were identified as the principle PTP1B inhibitory active compounds in Masiningan, and their actions were investigated in detail. These findings demonstrated the effectiveness of Masiningan on diabetes mellitus through the inhibition of PTP1B at a molecular level as well as the potential of magnolol (1) and chrysophanol (2) as lead compounds in future anti-diabetes drug development. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Bioactive compounds and encapsulation of Yanang (Tiliacora triandra) leaves.

PubMed

Singthong, Jittra; Oonsivilai, Ratchadaporn; Oonmetta-Aree, Jirawan; Ningsanond, Suwayd

2014-01-01

Yanang (Tiliacora triandra) has been known as vegetable and herbal in northeast Thailand and Lao People's Democratic Republic. Extracts from Yanang leaves contain high amounts of polyphenol constituents possessing antioxidant activity. This work investigated bioactive compounds of Yanang extracts prepared by infusion with water, ethanol and acetone. Furthermore, this paper reports the design of the experimental method for optimization of Yanang encapsulation using three independent variables: the ratio of core material (Yanang), to wall material (gum Arabic), gum Arabic concentration and inlet temperature of spray drying on bioactive compounds stability. The stability of bioactive compounds was evaluated using phenolic compounds, total antioxidant, carotenoids and chlorophyll. The study of the bioactivity of Yanang extracts found that extraction with water was the appropriate application. The study of Yanang encapsulation demonstrated that gum Arabic, as coating agents, protected bioactive compounds of Yanang. Optimized condition for the encapsulation was at the ratio of core to wall {1:4}, in gum Arabic concentration 10% (w/v), and inlet temperature at 160▯C. The results show that the bioactive compounds were mainly affected by the ratio of core to wall material. Besides, moisture content and particle size of encapsulation depend on inlet temperature of spray drying, and gum Arabic concentration, respectively. This optimization reveals that the encapsulation process did not lose the bioactive compounds. Yanang extract with water was the main phenolic compound and showed high antioxidant activities. This study demonstrates the potentials of using spray drying process and optimization for the encapsulation of herbal products.

Differential nephrotoxicity of cisplatin and a novel series of traditional Chinese medicine-platinum anticancer agents correlates with their chemical reactivity towards sulfur-containing nucleophiles.

PubMed

To, Kenneth K W; Au-Yeung, Steve C F; Ho, Yee-Ping

2006-07-01

A series of novel traditional Chinese medicine-platinum compounds has been found to be active against a number of murine and human cancers both in vitro and in vivo. Their high potency and the lack of cisplatin cross-resistance are believed to be due to the inclusion of the protein phosphatase 2A-inhibiting demethylcantharidin in the novel structures. A simple reversed-phase high-performance liquid chromatographic method was developed and validated as a stability-indicating assay for the platinum compounds. Using cisplatin and carboplatin as reference compounds, the stability study agrees well with the literature-reported findings. The novel traditional Chinese medicine-platinum compounds were more stable than cisplatin in water and dextrose, but became unstable in normal saline, a characteristic similar to that of carboplatin. The developed assay was further applied to study the chemical reactivity of the novel platinum compounds towards physiologically important nucleophiles such as glutathione and cysteine. The novel compounds were considerably less reactive to the sulfur-containing nucleophiles than cisplatin. In-vitro cytotoxicity assay was performed in a porcine kidney LLC-PK1 cell line model to investigate the nephrotoxicity potential of the platinum compounds. The lower rate of hydrolysis and the decreased reactivity of the novel traditional Chinese medicine-platinum compounds towards sulfur-containing bionucleophiles appear to have reduced their toxicity when compared with cisplatin, yet the antitumor activities of the novel compounds have not been compromised.

Exploration of avocado by-products as natural sources of bioactive compounds.

PubMed

Tremocoldi, Maria Augusta; Rosalen, Pedro Luiz; Franchin, Marcelo; Massarioli, Adna Prado; Denny, Carina; Daiuto, Érica Regina; Paschoal, Jonas Augusto Rizzato; Melo, Priscilla Siqueira; Alencar, Severino Matias de

2018-01-01

This study aimed to evaluate the antioxidant, anti-inflammatory, and cytotoxic properties and phenolic composition of peel and seed of avocado varieties Hass and Fuerte using green solvents. Ethanol soluble compounds were identified in peel and seed of both varieties using HPLC-MS/MS and quantified using HPLC-DAD. Agro-industrial by-products of both varieties exhibited high radical scavenging activity against synthetic free radicals (DPPH and ABTS) and reactive oxygen species (peroxyl, superoxide, and hypochlorous acid) and high ability to reduce Fe3+ to Fe2+. The main compounds with significant contribution to the antioxidant activity determined by online HPLC-ABTS●+ analyses were procyanidin B2 and epicatechin in the peel and trans-5-O-caffeoyl-D-quinic acid, procyanidin B1, catechin, and epicatechin in the seed. Peel of Fuerte significantly suppressed TNF-α and nitric oxide (NO) release (459.3 pg/mL and 8.5 μM, respectively), possibly because of the high phenolic content and antioxidant activity detected. Avocado agro-industrial by-products can be used for food and pharmaceutical purposes due to their antioxidant and anti-inflammatory properties.

The effect of high-pressure processing on colour, bioactive compounds, and antioxidant activity in smoothies during refrigerated storage.

PubMed

Andrés, Víctor; Villanueva, María J; Tenorio, María D

2016-02-01

The effects of high-pressure processing--HPP--(450 and 600 MPa/3 min/20 °C) on the colour, carotenoids, ascorbic acid, polyphenols and antioxidant activity (FRAP and DPPH) of a smoothie were compared to thermal processing (80 °C/3 min). Stability during 45 days at 4 °C was also evaluated. HPP samples showed slight differences (p < 0.05) in colour compared to untreated smoothies. Both HPP significantly increased the extractability of lycopene, β-carotene and polyphenols compared to untreated samples. After HPP, ascorbic acid was retained by more than 92% of the initial content. The best results for antioxidant activity were obtained when HPP was applied at 600 MPa. FRAP and DPPH showed a high correlation with ascorbic acid (R(2) = 0.7135 and 0.8107, respectively) and polyphenolic compounds (R(2) = 0.6819 and 0.6935, respectively), but not with total carotenoids. Changes in bioactive compounds during the storage period were lower in the HPP smoothie than in the thermal-treated sample. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exploration of avocado by-products as natural sources of bioactive compounds

PubMed Central

Tremocoldi, Maria Augusta; Rosalen, Pedro Luiz; Franchin, Marcelo; Massarioli, Adna Prado; Denny, Carina; Daiuto, Érica Regina; Paschoal, Jonas Augusto Rizzato; Melo, Priscilla Siqueira

2018-01-01

This study aimed to evaluate the antioxidant, anti-inflammatory, and cytotoxic properties and phenolic composition of peel and seed of avocado varieties Hass and Fuerte using green solvents. Ethanol soluble compounds were identified in peel and seed of both varieties using HPLC-MS/MS and quantified using HPLC-DAD. Agro-industrial by-products of both varieties exhibited high radical scavenging activity against synthetic free radicals (DPPH and ABTS) and reactive oxygen species (peroxyl, superoxide, and hypochlorous acid) and high ability to reduce Fe3+ to Fe2+. The main compounds with significant contribution to the antioxidant activity determined by online HPLC-ABTS●+ analyses were procyanidin B2 and epicatechin in the peel and trans-5-O-caffeoyl-D-quinic acid, procyanidin B1, catechin, and epicatechin in the seed. Peel of Fuerte significantly suppressed TNF-α and nitric oxide (NO) release (459.3 pg/mL and 8.5 μM, respectively), possibly because of the high phenolic content and antioxidant activity detected. Avocado agro-industrial by-products can be used for food and pharmaceutical purposes due to their antioxidant and anti-inflammatory properties. PMID:29444125

N-cinnamoylated chloroquine analogues as dual-stage antimalarial leads.

PubMed

Pérez, Bianca C; Teixeira, Cátia; Albuquerque, Inês S; Gut, Jiri; Rosenthal, Philip J; Gomes, José R B; Prudêncio, Miguel; Gomes, Paula

2013-01-24

The control of malaria is challenged by drug resistance, and new antimalarial drugs are needed. New drug discovery efforts include consideration of hybrid compounds as potential multitarget antimalarials. Previous work from our group has demonstrated that hybrid structures resulting from cinnamic acid conjugation with heterocyclic moieties from well-known antimalarials present improved antimalarial activity. Now, we report the synthesis and SAR analysis of an expanded series of cinnamic acid derivatives displaying remarkably high activities against both blood- and liver-stage malaria parasites. Two compounds judged most promising, based on their in vitro activity and druglikeness according to the Lipinski rules and Veber filter, were active in vivo against blood-stage rodent malaria parasites. Therefore, the compounds reported represent a new entry as promising dual-stage antimalarial leads.

Evaluation of volatile components from spikenard: valerena-4,7(11)-diene is a highly active sedative compound.

PubMed

Takemoto, Hiroaki; Yagura, Toru; Ito, Michiho

2009-10-01

Valerena-4,7(11)-diene and beta-maaliene were isolated from spikenard for the first time, and the effects of inhaling these compounds were investigated. Both compounds reduced the locomotor activity of mice dose-dependently, even at a low dose. Valerena-4,7(11)-diene had a particularly profound effect, with the strongest sedative activity observed at a dose of 0.06%. Caffeine-treated mice that showed an area under the curve (AUC) for locomotor activity that was double that of controls were calmed to normal levels by administration of valerena-4,7(11)-diene. The continuous sleep time of pentobarbital-treated mice was prolonged by about 2.7 times with valerena-4,7(11)-diene, an effect similar to that of chlorpromazine administered orally.

Facile synthesis and biological evaluation of novel symmetrical biphenyls as antitumor agents.

PubMed

Zhang, Jie; Zhang, Yanmin; Pan, Xiaoyan; Wang, Chen; Hu, Zhigang; Wang, Sicen; He, Langchong

2012-03-01

As a continuation to our previous work in developing anticancer agents, eighteen symmetrical biphenyl derivatives structurally related to taspine were synthesized and evaluated in vitro and in vivo. All the compounds were prepared with varied substitutions in the phenyl ring of aniline moiety. The cytotoxicity and anticancer activity of biphenyls was evaluated against various human tumor and normal cell line. Antiproliferative assays indicated that some of them exhibited potent anticancer activity. The potent antiproliferative activity of these compounds against ECV304 suggested that these biphenyls could be served as antiangiogenic agents. The highly active compound (2) also exhibited potent growth inhibition against cancer cell lines in vivo. Our findings demonstrated that these symmetrical biphenyl derivatives would be a promising candidate as novel anticancer agents.

Graphene stabilized ultra-small CuNi nanocomposite with high activity and recyclability toward catalysing the reduction of aromatic nitro-compounds.

PubMed

Fang, Hao; Wen, Ming; Chen, Hanxing; Wu, Qingsheng; Li, Weiying

2016-01-07

Nowadays, it is of great significance and a challenge to design a noble-metal-free catalyst with high activity and a long lifetime for the reduction of aromatic nitro-compounds. Here, a 2D structured nanocomposite catalyst with graphene supported CuNi alloy nanoparticles (NPs) is prepared, and is promising for meeting the requirements of green chemistry. In this graphene/CuNi nanocomposite, the ultra-small CuNi nanoparticles (∼2 nm) are evenly anchored on graphene sheets, which is not only a breakthrough in the structures, but also brings about an outstanding performance in activity and stability. Combined with a precise optimization of the alloy ratios, the reaction rate constant of graphene/Cu61Ni39 reached a high level of 0.13685 s(-1), with a desirable selectivity as high as 99% for various aromatic nitro-compounds. What's more, the catalyst exhibited a unprecedented long lifetime because it could be recycled over 25 times without obvious performance decay or even a morphology change. This work showed the promise and great potential of noble-metal-free catalysts in green chemistry.

Impact of high hydrostatic pressure and pasteurization on the structure and the extractability of bioactive compounds of persimmon “Rojo Brillante”.

PubMed

Hernández-Carrión, M; Vázquez-Gutiérrez, J L; Hernando, I; Quiles, A

2014-01-01

Rojo Brillante is an astringent oriental persimmon variety with high levels of bioactive compounds such as soluble tannins, carotenoids, phenolic acids, and dietary fiber. The purpose of this study was to investigate the effects of high hydrostatic pressure (HHP) and pasteurization on the structure of the fruit and on the extractability of certain bioactive compounds. The microstructure was studied using light microscopy, transmission electron microscopy, and low temperature scanning electron microscopy, and certain physicochemical properties (carotenoid and total soluble tannin content, antioxidant activity, fiber content, color, and texture properties) were measured. The structural changes induced by HHP caused a rise in solute circulation in the tissues that could be responsible for the increased carotenoid level and the unchanged antioxidant activity in comparison with the untreated persimmon. In contrast, the changes that took place during pasteurization lowered the tannin content and antioxidant activity. Consequently, HHP treatment could improve the extraction of potentially bioactive compoundsxsts from persimmons. A high nutritional value ingredient to be used when formulating new functional foods could be obtained using HHP. © 2013 Institute of Food Technologists®

Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramasamy, Karthikeyan K.; Gray, Michel J.; Job, Heather M.

2016-04-10

tA highly versatile ethanol conversion process to selectively generate high value compounds is pre-sented here. By changing the reaction temperature, ethanol can be selectively converted to >C2alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al2O3cata-lyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensationor the acetone formation is the path taken in changing the product composition. This article containsthe catalytic activity comparison between the mono-functional and physical mixture counterpart to thehydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

DOE PAGES

Ramasamy, Karthikeyan K.; Gray, Michel; Job, Heather; ...

2016-02-03

Here, a highly versatile ethanol conversion process to selectively generate high value compounds is presented here. By changing the reaction temperature, ethanol can be selectively converted to >C 2 alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al 2O 3 catalyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensation or the acetone formation is the path taken in changing the product composition. This article contains the catalytic activity comparison between the mono-functional and physical mixture counterpart to the hydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

Interactions of polyphenols with carbohydrates, lipids and proteins.

PubMed

Jakobek, Lidija

2015-05-15

Polyphenols are secondary metabolites in plants, investigated intensively because of their potential positive effects on human health. Their bioavailability and mechanism of positive effects have been studied, in vitro and in vivo. Lately, a high number of studies takes into account the interactions of polyphenols with compounds present in foods, like carbohydrates, proteins or lipids, because these food constituents can have significant effects on the activity of phenolic compounds. This paper reviews the interactions between phenolic compounds and lipids, carbohydrates and proteins and their impact on polyphenol activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Virtual Screening Approach for the Identification of High Affinity Small Molecules Targeting BCR-ABL1 Inhibitors for the Treatment of Chronic Myeloid Leukemia.

PubMed

Sharda, Saphy; Sarmandal, Palash; Cherukommu, Shirisha; Dindhoria, Kiran; Yadav, Manisha; Bandaru, Srinivas; Sharma, Anudeep; Sakhi, Aditi; Vyas, Tanmay; Hussain, Tajamul; Nayarisseri, Anuraj; Singh, Sanjeev Kumar

2017-01-01

CML originates due to reciprocal translocation in Philadelphia chromosome leading to the formation of fusion product BCR-ABL which constitutively activates tyrosine kinase signaling pathways eventually leading to abnormal proliferation of granulocytic cells. As a therapeutic strategy, BCR-ABL inhibitors have been clinically approved which terminates its phosphorylation activity and retards cancer progression. However, a number of patients develop resistance to inhibitors which demand for the discovery of new inhibitors. Given the drawbacks of present inhibitors, by high throughput virtual screening approaches, present study pursues to identify high affinity compounds targeting BCR-ABL1 anticipated to have safer pharmacological profiles. Five established BCR-ABL inhibitors formed the query compounds for identification of structurally similar compounds by Tanimoto coefficient based linear fingerprint search with a threshold of 95% against PubChemdatabase. Assisted by MolDock algorithm all compounds were docked against BCR-ABL protein in order to retrieve high affinity compounds. The parents and similars were further tested for their ADMET propertiesand bioactivity. Rebastinib formed higher affinity inhibitor than rest of the four established compound investigated in the study. Interestingly, Rebastinib similar compound with Pubchem ID: 67254402 was also shown to have highest affinity than other similars including the similars of respective five parents. In terms of ADMET properties Pubchem ID: 67254402 had appreciable ADMET profile and bioactivity. However, Rebastinib still stood as the best inhibitor in terms of binding affinity and ADMET properties than Pubchem ID: 67254402. Nevertheless, owing to the similar pharmacological properties with Rebastinib, Pubchem ID: 67254402 can be expected to form potential BCR-ABL inhibitor. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Design, synthesis and activity of BBI608 derivatives targeting on stem cells.

PubMed

Zhou, Qifan; Peng, Chen; Du, Fangyu; Zhou, Linbo; Shi, Yajie; Du, Yang; Liu, Dongdong; Sun, Wenjiao; Zhang, Meixia; Chen, Guoliang

2018-05-10

STAT3 plays a vital role in maintaining the self-renewal of tumor stem cells. BBI608, a small molecule identified by its ability to inhibit gene transcription driven by STAT3 and cancer stemness properties, can inhibit stemness gene expression and kill stemness-high cancer cells isolated from a variety of cancer types. In order to improve the pharmacokinetic properties of BBI608 and the antitumor activity, a series of BBI608 derivatives were designed and synthesized here. Most of these compounds were more potent than BBI608 on HepG2 cells, compound LD-8 had the most potent inhibitory activity among them and was 5.4-fold more potent than BBI608 (IC 50  = 11.2 μM), but had considerable activity on normal liver cells L-02. Compounds LD-17 (IC 50  = 3.5 μM) and LD-19 (IC 50  = 2.9 μM) were found to possess significant inhibitory activities and good selectivity. The results showed that compound LD-19 was worthy to investigate further as a lead compound according to its potent inhibitory activity, ideal ClogP value and better water solubility. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Thiazole-based nitrogen mustards: Design, synthesis, spectroscopic studies, DFT calculation, molecular docking, and antiproliferative activity against selected human cancer cell lines

NASA Astrophysics Data System (ADS)

Łączkowski, Krzysztof Z.; Świtalska, Marta; Baranowska-Łączkowska, Angelika; Plech, Tomasz; Paneth, Agata; Misiura, Konrad; Wietrzyk, Joanna; Czaplińska, Barbara; Mrozek-Wilczkiewicz, Anna; Malarz, Katarzyna; Musioł, Robert; Grela, Izabela

2016-09-01

Synthesis, characterization and investigation of antiproliferative activity of ten thiazole-based nitrogen mustard against human cancer cells lines (MV4-11, A549, MCF-7 and HCT116) and normal mouse fibroblast (BALB/3T3) is presented. The structures of novel compounds were determined using 1H and 13C NMR, FAB(+)-MS, and elemental analyses. Among the derivatives, 5b, 5c, 5e, 5f and 5i were found to exhibit high activity against human leukaemia MV4-11 cells with IC50 values of 2.17-4.26 μg/ml. The cytotoxic activity of compound 5c and 5f against BALB/3T3 cells is up to 20 times lower than against cancer cell lines. Our results also show that compounds 5e and 5i have very strong activity against MCF-7 and HCT116 with IC50 values of 3.02-4.13 μg/ml. Moreover, spectroscopic characterization and cellular localization for selected compound were performed. In order to identify potential drug targets we perform computer simulations with DNA-binding site of hTopoI and hTopoII and quantum chemical calculation of interaction and binding energies in complexes of the five most active compounds with guanine.

Design, Synthesis, in Vitro, and in Vivo Anticancer and Antiangiogenic Activity of Novel 3-Arylaminobenzofuran Derivatives Targeting the Colchicine Site on Tubulin

PubMed Central

Romagnoli, Romeo; Baraldi, Pier Giovanni; Salvador, Maria Kimatrai; Prencipe, Filippo; Lopez-Cara, Carlota; Ortega, Santiago Schiaffino; Brancale, Andrea; Hamel, Ernest; Castagliuolo, Ignazio; Mitola, Stefania; Ronca, Roberto; Bortolozzi, Roberta; Porcù, Elena; Basso, Giuseppe; Viola, Giampietro

2015-01-01

A new series of compounds characterized by the presence of a 2-methoxy/ethoxycarbonyl group, combined with either no substituent or a methoxy group at each of the four possible positions of the benzene portion of the 3-(3′,4′,5′-trimethoxyanilino)benzo[b]furan skeleton, were evaluated for antiproliferative activity against cancer cells in culture and, for selected, highly active compounds, inhibition of tubulin polymerization, cell cycle effects, and in vivo potency. The greatest antiproliferative activity occurred with a methoxy group introduced at the C-6 position, the least with this substituent at C-4. Thus far, the most promising compound in this series was 2-methoxycarbonyl-3-(3′,4′,5′-trimethoxyanilino)-6-methoxybenzo-[b]furan (3g), which inhibited cancer cell growth at nanomolar concentrations (IC50 values of 0.3–27 nM), bound to the colchicine site of tubulin, induced apoptosis, and showed, both in vitro and in vivo, potent vascular disrupting properties derived from the effect of this compound on vascular endothelial cells. Compound 3g had in vivo antitumor activity in a murine model comparable to the activity obtained with combretastatin A-4 phosphate. PMID:25785605

New Horizons in C-F Activation by Main Group Electrophiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozerov, Oleg V.

2016-02-13

This technical report describes progress on the DOE sponsored project "New Horizons in C-F Activation by Main Group Electrophiles" during the period of 09/15/2010 – 08/31/2015. The main goal of this project was to develop improved catalysts for conversion of carbon-fluorine bonds in potentially harmful compounds. The approach involved combining of a highly reactive positively charged main-group compound with a highly unreactive negatively charged species (anions) as a way to access potent catalysts for carbon-fluorine bond activation. This report details progress made in improving synthetic pathways to a variety of new anions with improved properties and analysis of their potentialmore » in catalysis.« less

High-Throughput Screening and Hit Validation of Extracellular-Related Kinase 5 (ERK5) Inhibitors.

PubMed

Myers, Stephanie M; Bawn, Ruth H; Bisset, Louise C; Blackburn, Timothy J; Cottyn, Betty; Molyneux, Lauren; Wong, Ai-Ching; Cano, Celine; Clegg, William; Harrington, Ross W; Leung, Hing; Rigoreau, Laurent; Vidot, Sandrine; Golding, Bernard T; Griffin, Roger J; Hammonds, Tim; Newell, David R; Hardcastle, Ian R

2016-08-08

The extracellular-related kinase 5 (ERK5) is a promising target for cancer therapy. A high-throughput screen was developed for ERK5, based on the IMAP FP progressive binding system, and used to identify hits from a library of 57 617 compounds. Four distinct chemical series were evident within the screening hits. Resynthesis and reassay of the hits demonstrated that one series did not return active compounds, whereas three series returned active hits. Structure-activity studies demonstrated that the 4-benzoylpyrrole-2-carboxamide pharmacophore had excellent potential for further development. The minimum kinase binding pharmacophore was identified, and key examples demonstrated good selectivity for ERK5 over p38α kinase.

Predicted Biological Activity of Purchasable Chemical Space

PubMed Central

2017-01-01

Whereas 400 million distinct compounds are now purchasable within the span of a few weeks, the biological activities of most are unknown. To facilitate access to new chemistry for biology, we have combined the Similarity Ensemble Approach (SEA) with the maximum Tanimoto similarity to the nearest bioactive to predict activity for every commercially available molecule in ZINC. This method, which we label SEA+TC, outperforms both SEA and a naïve-Bayesian classifier via predictive performance on a 5-fold cross-validation of ChEMBL’s bioactivity data set (version 21). Using this method, predictions for over 40% of compounds (>160 million) have either high significance (pSEA ≥ 40), high similarity (ECFP4MaxTc ≥ 0.4), or both, for one or more of 1382 targets well described by ligands in the literature. Using a further 1347 less-well-described targets, we predict activities for an additional 11 million compounds. To gauge whether these predictions are sensible, we investigate 75 predictions for 50 drugs lacking a binding affinity annotation in ChEMBL. The 535 million predictions for over 171 million compounds at 2629 targets are linked to purchasing information and evidence to support each prediction and are freely available via https://zinc15.docking.org and https://files.docking.org. PMID:29193970

Screening of Natural Product Derivatives Identifies Two Structurally Related Flavonoids as Potent Quorum Sensing Inhibitors against Gram-Negative Bacteria.

PubMed

Manner, Suvi; Fallarero, Adyary

2018-05-03

Owing to the failure of conventional antibiotics in biofilm control, alternative approaches are urgently needed. Inhibition of quorum sensing (QS) represents an attractive target since it is involved in several processes essential for biofilm formation. In this study, a compound library of natural product derivatives ( n = 3040) was screened for anti-quorum sensing activity using Chromobacterium violaceum as reporter bacteria. Screening assays, based on QS-mediated violacein production and viability, were performed in parallel to identify non-bactericidal QS inhibitors (QSIs). Nine highly active QSIs were identified, while 328 compounds were classified as moderately actives and 2062 compounds as inactives. Re-testing of the highly actives at a lower concentration against C. violaceum , complemented by a literature search, led to the identification of two flavonoid derivatives as the most potent QSIs, and their impact on biofilm maturation in Escherichia coli and Pseudomonas aeruginosa was further investigated. Finally, effects of these leads on swimming and swarming motility of P. aeruginosa were quantified. The identified flavonoids affected all the studied QS-related functions at micromolar concentrations. These compounds can serve as starting points for further optimization and development of more potent QSIs as adjunctive agents used with antibiotics in the treatment of biofilms.

Novel Phenoxazinones as potent agonist of PPAR-α: design, synthesis, molecular docking and in vivo studies.

PubMed

Ugwu, David I; Okoro, Uchechukwu C; Mishra, Narendra K; Okafor, Sunday N

2018-05-22

The use of statin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor for the treatment of dyslipidemia has been associated with dose limiting hepatoxicity, mytotoxicity and tolerability due to myalgias thereby necessitating the synthesis of new drug candidates for the treatment of lipid disorder. The reaction of appropriate benzenesulphonamide with substituted phenoxazinone in the presence of phenylboronic acid gave the targeted compounds. The molecular docking study were carried out using autodock tool against peroxisome proliferator activated receptor alpha. The in vivo lipid profile were assayed using conventional methods. The kidney and liver function test were carried out to assess the effect of the derivatives on the organs. The LD 50 of the most active derivatives were determined using mice. The targeted compounds were successfully synthesized in excellent yields and characterized using spectroscopic techniques. The results of the molecular docking experiment showed that they were good stimulant of peroxisome proliferator activated receptor alpha. Compound 9f showed activity at Ki of 2.8 nM and binding energy of 12.6 kcal/mol. All the compounds tested reduced triglyceride, total cholesterol, low density lipoprotein cholesterol and very low density lipoprotein cholesterol level in the mice model. Some of the reported compounds also increased high density lipoprotein cholesterol level in the mice. The compounds did not have appreciable effect on the kidney and liver of the mice used. The LD 50 showed that the novel compounds have improved toxicity profile. The synthesis of fifteen new derivatives of carboxamides bearing phenoxazinone and sulphonamide were successful. The compounds possessed comparable activity to gemfibrozil. The reported compounds had better toxicity profile than gemfibrozil and could serve as a replacement for the statins and fibrate class of lipid agents.

Synthesis of novel quinoline-based 4,5-dihydro-1H-pyrazoles as potential anticancer, antifungal, antibacterial and antiprotozoal agents.

PubMed

Ramírez-Prada, Jonathan; Robledo, Sara M; Vélez, Iván D; Crespo, María Del Pilar; Quiroga, Jairo; Abonia, Rodrigo; Montoya, Alba; Svetaz, Laura; Zacchino, Susana; Insuasty, Braulio

2017-05-05

A new series of N-substituted 2-pyrazolines 9a-f, 10a-f, 11a-f, 12a-f and 13a-f were obtained from the cyclocondensation reaction of [(7-chloroquinolin-4-yl)amino]chalcones 8a-f with hydrazine hydrate and its derivatives. Fourteen of the synthesized compounds including the starting chalcones were selected by US National Cancer Institute (NCI) for testing their anticancer activity against 60 different human cancer cell lines, with the most important GI 50 values ranging from 0.28 to 11.7 μM (0.13-6.05 μg/mL) and LC 50 values ranging from 2.6 to > 100 μM (1.2 to > 51.7 μg/mL), for chalcones 8a,d and pyrazolines 10c,d. All compounds were assessed for antibacterial activity against wild type and multidrug resistant gram negative and gram positive bacteria, with MIC values ranging from 31.25 to 500 μg/mL. Additionally, the novel compounds were tested for antifungal and antiparasitic properties. Although these compounds showed mild activity against Candida albicans, chalcones 8a and 8e showed high activity against Cryptococcus neoformans with MIC 50  = 7.8 μg/mL. For anti-Plasmodium falciparum activity the 2-pyrazoline 11b was the most active with EC 50  = 5.54 μg/mL. Regarding the activity against Trypanosoma cruzi, compound 10a was highly active with EC 50  = 0.70 μg/mL. Chalcone 8a had good activity against Leishmania panamensis amastigotes with EC 50  = 0.79 μg/mL. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A superoxide anion-scavenger, 1,3-selenazolidin-4-one suppresses serum deprivation-induced apoptosis in PC12 cells by activating MAP kinase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishina, Atsuyoshi, E-mail: nishina@yone.ac.jp; Kimura, Hirokazu; Kozawa, Kunihisa

Synthetic organic selenium compounds, such as ebselen, may show glutathione peroxidase-like antioxidant activity and have a neurotrophic effect. We synthesized 1,3-selenazolidin-4-ones, new types of synthetic organic selenium compounds (five-member ring compounds), to study their possible applications as antioxidants or neurotrophic-like molecules. Their superoxide radical scavenging effects were assessed using the quantitative, highly sensitive method of real-time kinetic chemiluminescence. At 166 {mu}M, the O{sub 2}{sup -} scavenging activity of 1,3-selenazolidin-4-ones ranged from 0 to 66.2%. 2-[3-(4-Methoxyphenyl)-4-oxo-1,3-selenazolidin-2-ylidene]malononitrile (compound b) showed the strongest superoxide anion-scavenging activity among the 6 kinds of 2-methylene-1,3-selenazolidin-4-ones examined. Compound b had a 50% inhibitory concentration (IC{sub 50}) atmore » 92.4 {mu}M and acted as an effective and potentially useful O{sub 2}{sup -} scavenger in vitro. The effect of compound b on rat pheochromocytome cell line PC12 cells was compared with that of ebselen or nerve growth factor (NGF) by use of the MTT [3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] assay. When ebselen was added at 100 {mu}M or more, toxicity toward PC12 cells was evident. On the contrary, compound b suppressed serum deprivation-induced apoptosis in PC12 cells more effectively at a concentration of 100 {mu}M. The activity of compound b to phosphorylate mitogen-activated protein kinase/extracellular signal-regulated protein kinase (ERK) 1/2 (MAP kinase) in PC12 cells was higher than that of ebselen, and the former at 100 {mu}M induced the phosphorylation of MAP kinase to a degree similar to that induced by NGF. From these results, we conclude that this superoxide anion-scavenger, compound b, suppressed serum deprivation-induced apoptosis by promoting the phosphorylation of MAP kinase. -- Highlights: Black-Right-Pointing-Pointer We newly synthesized 1,3-selenazolidin-4-ones to study their possible applications. Black-Right-Pointing-Pointer Among new compounds, compound b showed the strongest SOSA. Black-Right-Pointing-Pointer Compound b suppressed serum deprivation-induced apoptosis in PC12 cells. Black-Right-Pointing-Pointer Compound b suppressed apoptosis by promoting the activation of MAP kinase.« less

Antiretroviral Activity Of a Novel Pyrimidyl-Di(Diazaspiroalkane) Derivative.

PubMed

Novoselova, E A; Riabova, O B; Leneva, I A; Nesterenko, V G; Bolgarin, R N; Makarov, V A

2017-01-01

A novel compound, 3,3'-(5-nitropyrimidine-4,6-diyl)bis-3,12-diaza-6,9-diazoniadispiro[5.2.5.2]hexadecane tetrachloride dihydrochloride, was synthesized. The compound was found to inhibit the replication of various viral families by blocking specific heparan sulfate receptors on the host cell's surface. In experiments, the compound was found to be highly effective against several strains of HIV retroviruses.

Development and Validation of a High Throughput Screen for Compounds with Antiviral Activity Against Encephalitic Alphaviruses

DTIC Science & Technology

2010-09-15

viruses , including West Nile virus (WNV) 7 (PubChem AID: 1635), respiratory syncytial virus (PubChem AID: 2440...such as West Nile virus assay with a threshold value of 3.42%. D. Single Dose experiment with Arbo virus ...compounds. RESULT 1. Hit compounds nomination A. Arbo virus hits (1) SMR000372439 and SMR000058373 : Informatics analysis discovered

Influence of Culturing Conditions on Bioprospecting and the Antimicrobial Potential of Endophytic Fungi from Schinus terebinthifolius.

PubMed

Tonial, Fabiana; Maia, Beatriz H L N S; Gomes-Figueiredo, Josiane A; Sobottka, Andrea M; Bertol, Charise D; Nepel, Angelita; Savi, Daiani C; Vicente, Vânia A; Gomes, Renata R; Glienke, Chirlei

2016-02-01

In this study, we analyzed the antimicrobial activity of extracts harvested from 17 endophytic fungi isolated from the medicinal plant Schinus terebinthifolius. Morphological and molecular analyses indicated that these fungal species belonged to the genera Alternaria, Bjerkandera, Colletotrichum, Diaporthe, Penicillium, and Xylaria. Of the endophytes analyzed, 64.7 % produced antimicrobial compounds under at least one of the fermentation conditions tested. Nine isolates produced compounds that inhibited growth of Staphylococcus aureus, four produced compounds that inhibited Candida albicans, and two that inhibited Pseudomonas aeruginosa. The fermentation conditions of the following endophytes were optimized: Alternaria sp. Sect. Alternata-LGMF626, Xylaria sp.-LGMF673, and Bjerkandera sp.-LGMF713. Specifically, the carbon and nitrogen sources, initial pH, temperature, and length of incubation were varied. In general, production of antimicrobial compounds was greatest when galactose was used as a carbon source, and acidification of the growth medium enhanced the production of compounds that inhibited C. albicans. Upon large-scale fermentation, Alternaria sp. Sect. Alternata-LGMF626 produced an extract containing two fractions that were active against methicillin-resistant S. aureus. One of the extracts exhibited high activity (minimum inhibitory concentration of 18.52 µg/mL), and the other exhibited moderate activity (minimum inhibitory concentration of 55.55 µg/mL). The compounds E-2-hexyl-cinnamaldehyde and two compounds of the pyrrolopyrazine alkaloids class were identified in the active fractions by gas chromatography-mass spectrometry.

Control of 5-aminolaevulinate synthetase activity in Rhodopseudomonas spheroides. The involvement of sulphur metabolism

PubMed Central

Neuberger, Albert; Sandy, John D.; Tait, George H.

1973-01-01

1. The `initial' 5-aminolaevulinate synthetase activity, that is the activity observed immediately after cell disruption, in extracts prepared from unharvested semianaerobically grown Rhodopseudomonas spheroides, was twice that observed under the same assay conditions in extracts prepared from harvested cells. 2. The effect of oxygenation of a culture on the `maximum' aminolaevulinate synthetase activity, that is the activity observed 1h after disruption of harvested cells, is markedly influenced by the contents of the growth medium. Oxygenation of organisms for 1h in the medium in which they have grown produces an 80–90% decrease in maximum activity, whereas similar treatment of organisms resuspended in fresh medium produces less than a 40% decrease. 3. This protective effect of fresh medium is absolutely dependent on the presence of sulphate. When cells are suspended in sulphate-deficient fresh medium, the maximum activity falls by 65–75% even without oxygenation. A high maximum activity is regenerated when sulphate is resupplied. 4. When organisms are oxygenated in the medium in which they have grown, the cellular contents of GSH+GSSG and cysteine+cystine fall very markedly and homolanthionine is formed. Both the fall in aminolaevulinate synthetase activity and the changes in sulphur metabolism are largely prevented by the addition of compounds which stimulate synthesis of cysteine de novo or inhibit the conversion of cysteine S into homocysteine S. 5. The maximum aminolaevulinate synthetase activity was directly proportional to the GSH+GSSG content of all cell preparations. In glutathione-depleted extracts the `low'-activity enzyme could be re-activated in vitro by the addition of GSH, GSSG, cysteine or cystine, whereas in extracts with a high glutathione content the `high'-activity enzyme was unaffected by these sulphur compounds. 6. The activation of low-activity enzyme with exogenous sulphur compounds was prevented by excluding air or by adding NADH. Studies with purified enzyme indicate that sulphur compounds do not interact directly with the enzyme, but that their effect is mediated by a number of other endogenous factors. PMID:4544404

In silico studies and fluorescence binding assays of potential anti-prion compounds reveal an important binding site for prion inhibition from PrP(C) to PrP(Sc).

PubMed

Pagadala, Nataraj S; Perez-Pineiro, Rolando; Wishart, David S; Tuszynski, Jack A

2015-02-16

To understand the pharmacophore properties of 2-aminothiazoles and design novel inhibitors against the prion protein, a highly predictive 3D quantitative structure-activity relationship (QSAR) has been developed by performing comparative molecular field analysis (CoMFA) and comparative similarity analysis (CoMSIA). Both CoMFA and CoMSIA maps reveal the presence of the oxymethyl groups in meta and para positions on the phenyl ring of compound 17 (N-[4-(3,4-dimethoxyphenyl)-1,3-thiazol-2-yl]quinolin-2-amine), is necessary for activity while electro-negative nitrogen of quinoline is highly favorable to enhance activity. The blind docking results for these compounds show that the compound with quinoline binds with higher affinity than isoquinoline and naphthalene groups. Out of 150 novel compounds retrieved using finger print analysis by pharmacophoric model predicted based on five test sets of compounds, five compounds with diverse scaffolds were selected for biological evaluation as possible PrP inhibitors. Molecular docking combined with fluorescence quenching studies show that these compounds bind to pocket-D of SHaPrP near Trp145. The new antiprion compounds 3 and 6, which bind with the interaction energies of -12.1 and -13.2 kcal/mol, respectively, show fluorescence quenching with binding constant (Kd) values of 15.5 and 44.14 μM, respectively. Further fluorescence binding assays with compound 5, which is similar to 2-aminothiazole as a positive control, also show that the molecule binds to the pocket-D with the binding constant (Kd) value of 84.7 μM. Finally, both molecular docking and a fluorescence binding assay of noscapine as a negative control reveals the same binding site on the surface of pocket-A near a rigid loop between β2 and α2 interacting with Arg164. This high level of correlation between molecular docking and fluorescence quenching studies confirm that these five compounds are likely to act as inhibitors for prion propagation while noscapine might act as a prion accelerator from PrP(C) to PrP(Sc). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Biological activities of extracts from Chinese bayberry (Myrica rubra Sieb. et Zucc.): a review.

PubMed

Sun, Chongde; Huang, Huizhong; Xu, Changjie; Li, Xian; Chen, Kunsong

2013-06-01

Chinese bayberry (Myrica rubra Sieb. et Zucc.) is a subtropical fruit tree native to China and other Asian countries, and culture of this Myricaceae plant has been recorded in Chinese history for more than 2000 years. Bayberry fruit is delicious with attractive color, flavor, and high economic value. Compared with other berries, bayberry fruit is a rich source of cyanidin-3-glucoside (C3G, e.g., 64.8 mg/100 g fresh weight in 'Biqi' cultivar), which accounts for at least 85 % of the anthocyanins in the fruit. Bayberry is also a plant with high medicinal value since different organs have been used historically as folk medicines. Research efforts suggest bayberry extracts contain antioxidants that exhibit bioactivities counteracting inflammation, allergens, diabetes, cancer, bacterial infection, diarrhea and other health issues. Bayberry compounds have been isolated and characterized to provide a better understanding of the chemical mechanisms underlying the biological activities of bayberry extracts and to elaborate the structure-activity relationships. As the identification of compounds progresses, studies investigating the in vivo metabolism and bioavailability as well as potential toxicity of bayberry extracts in animal models are receiving more attention. In addition, breeding and genetic studies of bayberry with high accumulation of health-benefiting compounds may provide new insight for the bayberry research and industry. This review is focused on the main medicinal properties reported and the possible pharmaceutically active compounds identified in different bayberry extracts.

Enhancement of Phenolic Production and Antioxidant Activity from Buckwheat Leaves by Subcritical Water Extraction.

PubMed

Kim, Dong-Shin; Kim, Mi-Bo; Lim, Sang-Bin

2017-12-01

To enhance the production of phenolic compounds with high antioxidant activity and reduce the level of phototoxic fagopyrin, buckwheat leaves were extracted with subcritical water (SW) at 100~220°C for 10~50 min. The major phenolic compounds were quercetin, gallic acid, and protocatechuic acid. The cumulative amount of individual phenolic compounds increased with increasing extraction temperature from 100°C to 180°C and did not change significantly at 200°C and 220°C. The highest yield of individual phenolic compounds was 1,632.2 μg/g dry sample at 180°C, which was 4.7-fold higher than that (348.4 μg/g dry sample) at 100°C. Total phenolic content and total flavonoid content increased with increasing extraction temperature and decreased with increasing extraction time, and peaked at 41.1 mg gallic acid equivalents/g and 26.9 mg quercetin equivalents/g at 180°C/10 min, respectively. 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging activity and ferric reducing ability of plasma reached 46.4 mg ascorbic acid equivalents/g and 72.3 mmol Fe 2+ /100 g at 180°C/10 min, respectively. The fagopyrin contents were reduced by 92.5~95.7%. Color values L * and b * decreased, and a * increased with increasing extraction temperature. SW extraction enhanced the yield of phenolic compounds with high antioxidant activity and reduced the fagopyrin content from buckwheat leaves.

Structural features, kinetics and SAR study of radical scavenging and antioxidant activities of phenolic and anilinic compounds

PubMed Central

2013-01-01

Background Phenolic compounds are widely distributed in plant kingdom and constitute one of the most important classes of natural and synthetic antioxidants. In the present study fifty one natural and synthetic structurally variant phenolic, enolic and anilinic compounds were examined as antioxidants and radical scavengers against DPPH, hydroxyl and peroxyl radicals. The structural diversity of the used phenolic compounds includes monophenols with substituents frequently present in natural phenols e.g. alkyl, alkoxy, ester and carboxyl groups, besides many other electron donating and withdrawing groups, in addition to polyphenols with 1–3 hydroxyl groups and aminophenols. Some common groups e.g. alkyl, carboxyl, amino and second OH groups were incorporated in ortho, meta and para positions. Results SAR study indicates that the most important structural feature of phenolic compounds required to possess good antiradical and antioxidant activities is the presence of a second hydroxyl or an amino group in o- or p-position because of their strong electron donating effect in these positions and the formation of a stable quinone-like products upon two hydrogen-atom transfer process; otherwise, the presence of a number of alkoxy (in o or p-position) and /or alkyl groups (in o, m or p-position) should be present to stabilize the resulted phenoxyl radical and reach good activity. Anilines showed also similar structural feature requirements as phenols to achieve good activities, except o-diamines which gave low activity because of the high energy of the resulted 1,2-dimine product upon the 2H-transfer process. Enols with ene-1,2-diol structure undergo the same process and give good activity. Good correlations were obtained between DPPH inhibition and inhibition of both OH and peroxyl radicals. In addition, good correlations were obtained between DPPH inhibition and antioxidant activities in sunflower oil and liver homogenate systems. Conclusions In conclusion, the structures of good anti radical and antioxidant phenols and anilines are defined. The obtained good correlations imply that measuring anti DPPH activity can be used as a simple predictive test for the anti hydroxyl and peroxyl radical, and antioxidant activities. Kinetic measurements showed that strong antioxidants with high activity have also high reaction rates indicating that factors stabilizing the phenoxyl radicals lower also the activation energy of the hydrogen transfer process. PMID:23497653

Synthesis and QSAR study of novel α-methylene-γ-butyrolactone derivatives as antifungal agents.

PubMed

Wu, Yong-Ling; Wang, De-Long; Guo, En-Hui; Song, Shuang; Feng, Jun-Tao; Zhang, Xing

2017-03-01

Thirty-six new α-benzylidene-γ-lactone compounds based α-methylene-γ-butyrolactone substructure were prepared and characterized by spectroscopic analysis. All compounds were evaluated for antifungal activities in vitro against six plant pathogenic fungi and the half maximal inhibitory concentration (IC 50 ) against Botrytis cinerea and Colletotrichum lagenarium were investigated. Compounds 5c-3 and 5c-5 with the halogen atom exhibited excellent fungicidal activity against B. cinerea (IC 50 =22.91, 18.89μM). The structure-activity relationships (SARs) analysis indicated that the derivatives with electron-withdrawing substituents at the meta- or para-positions improves the activity. Via the heuristic method, the generated quantitative structure-activity relationship (QSAR) model (R 2 =0.961) revealed a strong correlation of antifungal activity against B. cinerea with molecular structures of these compounds. Meanwhile, the cytotoxicity of 20 representative derivatives was tested in the human tumor cells line (HepG2) and the hepatic L02 cells line, the result indicated that the synthesized compounds showed significant inhibitory activity and limited selectivity. Compound 5c-5 has the highest fungicidal activity with IC 50 =18.89μM (against B. cinerea.) but low cytotoxicity with IC 50 =35.4μM (against HepG2 cell line) and IC 50 =68.8μM (against Hepatic L02 cell line). These encouraging results can be providing an alternative, promising use of α-benzylidene-γ-lactone through the design and exploration of eco-friendly fungicides with low toxicity and high efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

High efficiency capillary column-gas chromatography mass spectrometry: analysis of the lipoxygenase pathway in eukaryot cells.

PubMed

Rabinovitch-Chable, H; Durand, J; Aldigier, J C; Chebroux, P; Gualde, N; Beneytout, J L; Rigaud, M

1984-01-01

Lipoxygenases are ubiquitous enzymes able to oxygenate polyunsaturated fatty acids. This metabolic pathway leads to hydroperoxides, hydroxyepoxyene compounds and leukotrienes. Using high performance gas chromatography prior to mass spectrometry, we studied the activity of the lipoxygenases from mouse peritoneal macrophages. Further studies on mechanism of biosynthesis of hydroxyepoxyene compounds were successfully carried out using 18O2 labelled precursors.

Diterpenoids from Salvia ceratophylla.

PubMed

Gören, Ahmet C; Topçu, Gülaçti; Oksüz, Sevil; Kökdil, Gamze; Voelter, Wolfgang; Ulubelen, Ayhan

2002-02-01

Salvia ceratophylla L. has yielded four known and two new diterpenoids together with two triterpenic acids, a steroid and a flavone. The structures of the compounds were established by spectroscopic analyses. One of the known compounds candidissiol exhibited a high antibacterial activity against Staphylococcus epidermidis and Proteus mirabilis.

Comparison of content in phenolic compounds, polyphenol oxidase, and peroxidase in grains of fifty sorghum varieties from burkina faso.

PubMed

Dicko, Mamoudou H; Hilhorst, Riet; Gruppen, Harry; Traore, Alfred S; Laane, Colja; van Berkel, Willem J H; Voragen, Alphons G J

2002-06-19

Analysis of fifty sorghum [Sorghum bicolor (L.) Moench] varieties used in Burkina Faso showed that they have different contents of phenolic compounds, peroxidase (POX), and polyphenol oxidase (PPO). Most of the varieties (82%) had a tannin content less than 0.25% (w/w). POX specific activity was higher than the monophenolase and o-diphenolase specific activities of PPO. For POX, there was a diversity of isoforms among varieties. No clear correlation could be made between the quantitative composition of the grain in phenolics, PPO, and POX, and resistance of plant to pathogens. In general, varieties good for a thick porridge preparation ("tô") had low phenolic compounds content and a medium POX activity. From the red varieties, those used for local beer ("dolo") had a high content in phenolic compounds and PPO, and a low POX activity. The variety considered good for couscous had a low POX content. The characteristics might be useful as selection markers for breeding for specific applications.

Novel N-allyl/propargyl tetrahydroquinolines: Synthesis via Three-component Cationic Imino Diels-Alder Reaction, Binding Prediction, and Evaluation as Cholinesterase Inhibitors.

PubMed

Rodríguez, Yeray A; Gutiérrez, Margarita; Ramírez, David; Alzate-Morales, Jans; Bernal, Cristian C; Güiza, Fausto M; Romero Bohórquez, Arnold R

2016-10-01

New N-allyl/propargyl 4-substituted 1,2,3,4-tetrahydroquinolines derivatives were efficiently synthesized using acid-catalyzed three components cationic imino Diels-Alder reaction (70-95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl-cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC50 = 72 μm) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl-cholinesterase was exhibited by compound 4ae (IC50 = 25.58 μm) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl-cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets. © 2016 The Authors Chemical Biology & Drug Design Published by John Wiley & Sons Ltd.

A "natural" approach: synthesis and cytoxicity of monodesmosidic glycyrrhetinic acid glycosides.

PubMed

Schwarz, Stefan; Siewert, Bianka; Xavier, Nuno M; Jesus, Ana R; Rauter, Amélia P; Csuk, René

2014-01-24

Several pentacyclic triterpenoic acids have shown noteworthy antitumor activity, among them betulinic acid as well as oleanolic acid and derivatives thereof. Glycyrrhetinic acid (GA) exhibits some cytotoxic activity albeit this compound is not as active as betulinic acid, but GA came in the focus of scientific interest since it triggers apoptosis in tumor cells. In addition, it can be extracted from the roots of liquorice in high yields. Previous studies revealed that the introduction of an extra hydrophilic moiety increases the cytotoxicity of these compounds. Thus, a series of GA glycosides was prepared utilizing hexoses as well as pentoses (in D- and L-configuration) by using glycosyl trichloroacetimidates and TMSOTf as catalyst. The compounds were screened for cytotoxic activity against seven human cancer cell lines and the not malignant murine cell line NIH 3T3using a photometric SRB assay. The compounds trigger apoptosis as shown from extra trypan blue and acridine orange/ethidium bromide staining. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Phenolic compounds and antioxidant activity of kernels and shells of Mexican pecan (Carya illinoinensis).

PubMed

de la Rosa, Laura A; Alvarez-Parrilla, Emilio; Shahidi, Fereidoon

2011-01-12

The phenolic composition and antioxidant activity of pecan kernels and shells cultivated in three regions of the state of Chihuahua, Mexico, were analyzed. High concentrations of total extractable phenolics, flavonoids, and proanthocyanidins were found in kernels, and 5-20-fold higher concentrations were found in shells. Their concentrations were significantly affected by the growing region. Antioxidant activity was evaluated by ORAC, DPPH•, HO•, and ABTS•-- scavenging (TAC) methods. Antioxidant activity was strongly correlated with the concentrations of phenolic compounds. A strong correlation existed among the results obtained using these four methods. Five individual phenolic compounds were positively identified and quantified in kernels: ellagic, gallic, protocatechuic, and p-hydroxybenzoic acids and catechin. Only ellagic and gallic acids could be identified in shells. Seven phenolic compounds were tentatively identified in kernels by means of MS and UV spectral comparison, namely, protocatechuic aldehyde, (epi)gallocatechin, one gallic acid-glucose conjugate, three ellagic acid derivatives, and valoneic acid dilactone.

Induction of quinone reductase (QR) by withanolides isolated from Physalis pubescens L. (Solanaceae).

PubMed

Ji, Long; Yuan, Yonglei; Ma, Zhongjun; Chen, Zhe; Gan, Lishe; Ma, Xiaoqiong; Huang, Dongsheng

2013-09-01

In the present study, it was demonstrated that the dichloromethane extract of Physalis pubescens L. (DEPP) had weak potential quinone reductase (QR) inducing activity, but an UPLC-ESI-MS method with glutathione (GSH) as the substrate revealed that the DEPP had electrophiles (with an α,β-unsaturated ketone moiety). These electrophiles could induce quinone reductase (QR) activity, which might be attributed to the modification of the highly reactive cysteine residues in Keap1. Herein, four withanolides, including three new compounds physapubescin B (2), physapubescin C (3), physapubescin D (4), together with one known steroidal compound physapubescin (1) were isolated. Structures of these compounds were determined by spectroscopic analysis and that of physapubescin C (3) was confirmed by a combination of molecular modeling and quantum chemical DFT-GIAO calculations. Evaluation of the QR inducing activities of all withanolides indicated potent activities of compounds 1 and 2, which had a common α,β-unsaturated ketone moiety. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development of electrospun nanofibers containing chitosan/PEO blend and phenolic compounds with antibacterial activity.

PubMed

Kuntzler, Suelen Goettems; Costa, Jorge Alberto Vieira; Morais, Michele Greque de

2018-05-31

Electrospun nanofibers can be formed with chitosan as the polymers found in biological sources have antibacterial ability. The objective of this work was to evaluate whether chitosan/polyethylene oxide (PEO) blend nanofibers containing microalgal phenolic compounds exhibit antibacterial activity. Nanofibers produced with a 3% chitosan/2% PEO blend containing 1% phenolic compounds had an average diameter of 214 ± 37 nm, which resulted in a high temperature of maximum degradation, an important parameter for food packaging. The potential antibacterial activity of this nanofibers was confirmed by their inhibition of Staphylococcus aureus ATCC 25923 (6.4 ± 1.1 mm) and Escherichia coli ATCC 25972 (5.5 ± 0.4 mm). The polymeric nanofibers produced from chitosan and containing phenolic compounds have properties that therefore allow their application as active packaging. In addition, chitosan is an excellent polymer for packaging as it presents biodegradability, biocompatibility and, non-toxicity. Copyright © 2018. Published by Elsevier B.V.

Exploration of acetanilide derivatives of 1-(ω-phenoxyalkyl)uracils as novel inhibitors of Hepatitis C Virus replication

PubMed Central

Magri, Andrea; Ozerov, Alexander A.; Tunitskaya, Vera L.; Valuev-Elliston, Vladimir T.; Wahid, Ahmed; Pirisi, Mario; Simmonds, Peter; Ivanov, Alexander V.; Novikov, Mikhail S.; Patel, Arvind H.

2016-01-01

Hepatitis C Virus (HCV) is a major public health problem worldwide. While highly efficacious directly-acting antiviral agents have been developed in recent years, their high costs and relative inaccessibility make their use limited. Here, we describe new 1-(ω-phenoxyalkyl)uracils bearing acetanilide fragment in 3 position of pyrimidine ring as potential antiviral drugs against HCV. Using a combination of various biochemical assays and in vitro virus infection and replication models, we show that our compounds are able to significantly reduce viral genomic replication, independently of virus genotype, with their IC50 values in the nanomolar range. We also demonstrate that our compounds can block de novo RNA synthesis and that effect is dependent on a chemical structure of the compounds. A detailed structure-activity relationship revealed that the most active compounds were the N3-substituted uracil derivatives containing 6-(4-bromophenoxy)hexyl or 8-(4-bromophenoxy)octyl fragment at N1 position. PMID:27406141

Exploration of acetanilide derivatives of 1-(ω-phenoxyalkyl)uracils as novel inhibitors of Hepatitis C Virus replication.

PubMed

Magri, Andrea; Ozerov, Alexander A; Tunitskaya, Vera L; Valuev-Elliston, Vladimir T; Wahid, Ahmed; Pirisi, Mario; Simmonds, Peter; Ivanov, Alexander V; Novikov, Mikhail S; Patel, Arvind H

2016-07-12

Hepatitis C Virus (HCV) is a major public health problem worldwide. While highly efficacious directly-acting antiviral agents have been developed in recent years, their high costs and relative inaccessibility make their use limited. Here, we describe new 1-(ω-phenoxyalkyl)uracils bearing acetanilide fragment in 3 position of pyrimidine ring as potential antiviral drugs against HCV. Using a combination of various biochemical assays and in vitro virus infection and replication models, we show that our compounds are able to significantly reduce viral genomic replication, independently of virus genotype, with their IC50 values in the nanomolar range. We also demonstrate that our compounds can block de novo RNA synthesis and that effect is dependent on a chemical structure of the compounds. A detailed structure-activity relationship revealed that the most active compounds were the N(3)-substituted uracil derivatives containing 6-(4-bromophenoxy)hexyl or 8-(4-bromophenoxy)octyl fragment at N(1) position.

[Simultaneously preparation of grams of high purity tyrosol, crenulatin and salidroside from Rhodiola crenulata].

PubMed

Luo, Xin; Wang, Xue-jing; Li, Shi-ping; Zhang, Qiao; Zhao, Yi-wu; Huang Wen-zhe; Wang, Zhen-zhong; Xiao, Wei

2015-04-01

Tyrosol, crenulatin and salidroside are the main active constituents of Rhodiola crenulata, with extensive pharmacological activities. In the study, grams of high purity tyrosol, crenulatin and salidroside were simultaneously separated from R. crenulata by the first time. Firstly, R. crenulata was extracted by 70% alcohol. Then, with the yields of three compounds as the index, the macroporous resin was optimized. At last, grams of high purity tyrosol, crenulatin and salidroside were isolated by D-101 macroporousresin, purified by column chromatography. Detected by HPLC, the purity of three compounds were higher than 98%. This method has the advantages of simple process and operation, less dosage of organic solvent, highly yield and reproducibility, suitable for the simultaneously preparation of tyrosol, crenulatin and salidroside.

Unraveling the structure and chemical mechanisms of highly oxygenated intermediates in oxidation of organic compounds.

PubMed

Wang, Zhandong; Popolan-Vaida, Denisia M; Chen, Bingjie; Moshammer, Kai; Mohamed, Samah Y; Wang, Heng; Sioud, Salim; Raji, Misjudeen A; Kohse-Höinghaus, Katharina; Hansen, Nils; Dagaut, Philippe; Leone, Stephen R; Sarathy, S Mani

2017-12-12

Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more hydroperoxy groups are prevalent in the autooxidation of various oxygenated (e.g., alcohol, aldehyde, keto compounds, ether, and ester) and nonoxygenated (e.g., normal alkane, branched alkane, and cycloalkane) organic compounds. These findings improve our understanding of autooxidation reaction mechanisms that are routinely used to predict fuel ignition and oxidative stability of liquid hydrocarbons, while also providing insights relevant to the formation mechanisms of tropospheric aerosol building blocks. The direct observation of highly oxygenated intermediates for the autooxidation of alkanes at 500-600 K builds upon prior observations made in atmospheric conditions for the autooxidation of terpenes and other unsaturated hydrocarbons; it shows that highly oxygenated intermediates are stable at conditions above room temperature. These results further reveal that highly oxygenated intermediates are not only accessible by chemical activation but also by thermal activation. Theoretical calculations on H-atom migration reactions are presented to rationalize the relationship between the organic compound's molecular structure ( n -alkane, branched alkane, and cycloalkane) and its propensity to produce highly oxygenated intermediates via extensive autooxidation of hydroperoxyalkylperoxy radicals. Finally, detailed chemical kinetic simulations demonstrate the influence of these additional reaction pathways on the ignition of practical fuels. Copyright © 2017 the Author(s). Published by PNAS.

Three New Highly Oxygenated Germacranolides from Carpesium Divaricatum and Their Cytotoxic Activity.

PubMed

Zhang, Tao; Si, Jin-Guang; Zhang, Qiu-Bo; Chen, Jia-Huan; Ding, Gang; Zhang, Hong-Wu; Jia, Hong-Mei; Zou, Zhong-Mei

2018-05-03

Three new highly oxygenated ( 2 ⁻ 4 ), and two known ( 1 and 5 ) germacranolides, were isolated from the whole plant of Carpesium divaricatum . The planar structures and relative configurations of the new compounds were determined by detailed spectroscopic analysis. The absolute configuration of 1 was established using the circular dichroism (CD) method and X-ray diffraction, and the stereochemistry of the new compounds 2 ⁻ 4 were determined using similar CD spectra with 1 . The new compound 2 and the known compound 5 exhibited potent cytotoxicity against hepatocellular cancer (Hep G2) and human cervical cancer (HeLa) cells, superior to those of the positive control cis -platin.

Aqua mediated synthesis of bio-active compounds.

PubMed

Panda, Siva S

2013-05-01

Recently the aqueous medium has attracted the interest of organic chemists, and many. Moreover, in the past 20 years, the drug-discovery process has undergone extraordinary changes, and high-throughput biological screening of potential drug candidates has led to an ever-increasing demand for novel drug-like compounds. Noteworthy advantages were observed during the course of study on aqua mediated synthesis of compounds of medicinal importance. The established advantages of water as a solvent for reactions are, water is the most abundant and available resource on the planet and many biochemical processes occur in aqueous medium. This review will focus on describing new developments in the application of water in medicinal chemistry for the synthesis of bio-active compounds possessing various biological properties.

Immunosuppressive compounds from a deep water marine sponge, Agelas flabelliformis.

PubMed

Gunasekera, S P; Cranick, S; Longley, R E

1989-01-01

Two immunosuppressive compounds, 4 alpha-methyl-5 alpha-cholest-8-en-3 beta-ol and 4,5-dibromo-2-pyrrolic acid were isolated from a deep water marine sponge, Agelas flabelliformis. Their structures were determined by comparison of their spectral data with those of samples isolated from other organisms. Both compounds were highly active in suppression of the response of murine splenocytes in the two-way mixed lymphocyte reaction (MLR) with little to no demonstrable cytotoxicity at lower doses. In addition, 4,5-dibromo-2-pyrrolic acid suppressed the proliferative response of splenocytes to suboptimal concentrations of the mitogen, concanavalin A (Con A). These results describe for the first time compounds isolated from the marine sponge A. flabelliformis that possess potent in vitro immunosuppressive activity.

Synthesis and study of thiocarbonate derivatives of choline as potential inhibitors of acetylcholinesterase.

PubMed

Boyle, N A; Talesa, V; Giovannini, E; Rosi, G; Norton, S J

1997-09-12

Fourteen alkyl and aryl thiocarbonate derivatives of choline were synthesized and studied as potential inhibitors of acetylcholinesterase (AChE). Twelve of the compounds inhibited AChEs derived from calf forebrain, human red blood cells, and octopus brain ranging from low to moderately high inhibition potency. The concentration of each inhibitory compound giving 50% inhibition of enzyme activity (IC50 values, which ranged from 1 x 10(-2) to 8 x 10(-7) M) was determined and is reported; inhibitor constants (Ki values) for the most inhibitory compounds, (1-pentylthiocarbonyl)choline chloride and (1-heptylthiocarbonyl)choline chloride, were calculated from kinetic data and are also reported. The inhibitors are competitive with substrate, and they are not hydrolyzed by the AChE activities. Certain of these new compounds may provide direction for the development of new drugs that have anticholinesterase activity and may be used for the treatment of Alzheimer's disease.

Removal of pharmaceutically active compounds in nitrifying-denitrifying plants.

PubMed

Suárez, S; Ramil, M; Omil, F; Lema, J M

2005-01-01

The behaviour of nine pharmaceutically active compounds (PhACs) of different diagnostic groups is studied during a nitrifying-denitrifying process in an activated sludge system. The compounds selected cover a wide range of frequently used substances such as anti-epileptics (carbamazepine), tranquillisers (diazepam), anti-depressants (fluoxetine and citalopram), anti-inflammatories (ibuprofen, naproxen and diclofenac) and estrogens (estradiol and ethinylestradiol). The main objective of this research is to investigate the effect of acclimation of biomass on the removal rates of these compounds, either by maintaining a high sludge retention time or at long-term operation. The removal rates achieved for nitrogen and carbon in the experimental unit exceed 90% and were not affected by the addition of PhACs. Carbamazepine, diazepam and diclofenac were only removed to a small extent. On the other hand, higher removal rates have been observed for naproxen and ibuprofen (68% and 82%), respectively.

H1-A, a compound isolated from Fusarium oxysporum inhibits hepatitis C virus (HCV) NS3 serine protease.

PubMed

Yang, Li-Yuan; Lin, Jun; Zhou, Bin; Liu, Yan-Gang; Zhu, Bao-Quan

2016-04-01

The present study was aimed to isolate the active compounds from the fermentation products of Fusarium oxysporum, which had hepatitis C virus (HCV) NS3 protease inhibitory activity. A bioactive compound was isolated by reverse-phase silica-gel column chromatography, silica-gel column chromatography, semi-preparative reverse-phase High Performance Liquid Chromatography (HPLC), and then its molecular structure was elucidated based on the spectrosopic analysis. As a result, the compound (H1-A, 1) Ergosta-5, 8 (14), 22-trien-7-one, 3-hydroxy-,(3β, 22E) was isolated and identified. To the best of our knowledge, this was the first report on the isolation of H1-A from microorganisms with the inhibitory activity of NS3 protease. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

High-Throughput Screening Using a Whole-Cell Virus Replication Reporter Gene Assay to Identify Inhibitory Compounds against Rift Valley Fever Virus Infection.

PubMed

Islam, Md Koushikul; Baudin, Maria; Eriksson, Jonas; Öberg, Christopher; Habjan, Matthias; Weber, Friedemann; Överby, Anna K; Ahlm, Clas; Evander, Magnus

2016-04-01

Rift Valley fever virus (RVFV) is an emerging virus that causes serious illness in humans and livestock. There are no approved vaccines or treatments for humans. The purpose of the study was to identify inhibitory compounds of RVFV infection without any preconceived idea of the mechanism of action. A whole-cell-based high-throughput drug screening assay was developed to screen 28,437 small chemical compounds targeting RVFV infection. To accomplish both speed and robustness, a replication-competent NSs-deleted RVFV expressing a fluorescent reporter gene was developed. Inhibition of fluorescence intensity was quantified by spectrophotometry and related to virus infection in human lung epithelial cells (A549). Cell toxicity was assessed by the Resazurin cell viability assay. After primary screening, 641 compounds were identified that inhibited RVFV infection by ≥80%, with ≥50% cell viability at 50 µM concentration. These compounds were subjected to a second screening regarding dose-response profiles, and 63 compounds with ≥60% inhibition of RVFV infection at 3.12 µM compound concentration and ≥50% cell viability at 25 µM were considered hits. Of these, six compounds with high inhibitory activity were identified. In conclusion, the high-throughput assay could efficiently and safely identify several promising compounds that inhibited RVFV infection. © 2016 Society for Laboratory Automation and Screening.

Novel long-chain compounds with both immunomodulatory and MenA inhibitory activities against Staphylococcus aureus and its biofilm.

PubMed

Choi, Seoung-Ryoung; Frandsen, Joel; Narayanasamy, Prabagaran

2017-01-10

Menaquinone (MK) biosynthesis pathway is a potential target for evaluating antimicrobials in gram-positive bacteria. Here, 1,4-dihydroxy-2-naphthoate prenyltransferase (MenA) was targeted to reduce methicillin-resistant Staphylococcus aureus (MRSA) growth. MenA inhibiting, long chain-based compounds were designed, synthesized and evaluated against MRSA and menaquinone utilizing bacteria in aerobic conditions. The results showed that these bacteria were susceptible to most of the compounds. Menaquinone (MK-4) supplementation rescued MRSA growth, suggesting these compounds inhibit MK biosynthesis. 3a and 7c exhibited promising inhibitory activities with MICs ranging 1-8 μg/mL against MRSA strains. The compounds did not facilitate small colony variant formation. These compounds also inhibited the biofilm growth by MRSA at high concentration. Compounds 3a, 6b and 7c displayed a promising extracellular bactericidal activity against MRSA at concentrations equal to and four-fold less than their respective MICs. We also observed cytokines released from THP-1 macrophages treated with compounds 3a, 6b and 7c and found decreases in TNF-α and IL-6 release and increase in IL-1β. These data provide evidence that MenA inhibitors act as TNF-α and IL-6 inhibitors, raising the potential for development and application of these compounds as potential immunomodulatory agents.

Polyphenolic Compounds and Antioxidant Activity of Cold-Pressed Seed Oil from Finola Cultivar of Cannabis sativa L.

PubMed

Smeriglio, Antonella; Galati, Enza M; Monforte, Maria T; Lanuzza, Francesco; D'Angelo, Valeria; Circosta, Clara

2016-08-01

The aim of this study was to characterize the polyphenolic compounds and antioxidant activity of cold-pressed seed oil from Finola cultivar of industrial hemp (Cannabis sativa L.). Several methodologies have been employed to evaluate the in vitro antioxidant activity of Finola hempseed oil (FHSO) and both lipophilic (LF) and hydrophilic fractions (HF). The qualitative and quantitative composition of the phenolic fraction of FHSO was performed by HPLC analyses. From the results is evident that FHSO has high antioxidative activity, as measured by DPPH radical (146.76 mmol of TE/100 g oil), inhibited β-carotene bleaching, quenched a chemically generated peroxyl radical in vitro and showed high ferrous ion chelating activity. Reactivity towards 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation and ferric-reducing antioxidant power values were 695.2 µmol of TE/100g oil and 3690.6 µmol of TE/100 g oil respectively. FHSO contains a significant amount of phenolic compounds of which 2780.4 mg of quercetin equivalent/100 g of total flavonoids. The whole oil showed higher antioxidant activity compared with LF and HF. Our findings indicate that the significant antioxidant properties shown from Finola seed oil might generally depend on the phenolic compounds, especially flavonoids, such as flavanones, flavonols, flavanols and isoflavones. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Novel CYP17 inhibitors: synthesis, biological evaluation, structure-activity relationships and modelling of methoxy- and hydroxy-substituted methyleneimidazolyl biphenyls.

PubMed

Hille, Ulrike E; Hu, Qingzhong; Vock, Carsten; Negri, Matthias; Bartels, Marc; Müller-Vieira, Ursula; Lauterbach, Thomas; Hartmann, Rolf W

2009-07-01

Recently, the steroidal CYP17 inhibitor Abiraterone entered phase II clinical trial for the treatment of androgen-dependent prostate cancer. As 17alpha-hydroxylase-17,20-lyase (CYP17) catalyzes the last step in androgen biosynthesis, inhibition of this target should affect not only testicular but also adrenal androgen formation. Therefore CYP17 inhibitors should be advantageous over existing therapies, for example with GnRH analogues. However, steroidal drugs are known for side effects which are due to affinities for steroid receptors. Therefore we decided to synthesize non-steroidal compounds mimicking the natural CYP17 substrates pregnenolone and progesterone. The synthesis and biological evaluation of a series of 15 novel and highly active non-steroidal CYP17 inhibitors are reported. The compounds were prepared via Suzuki-cross-coupling, Grignard reaction and CDI-assisted S(N)t-reaction with imidazole and their inhibitory activity was examined with recombinant human CYP17 expressed in Escherichia coli. Promising compounds were further tested for their selectivity against the hepatic enzyme CYP3A4 and the glucocorticoid-forming enzyme CYP11B1. All compounds turned out to be potent CYP17 inhibitors. The most active compounds 7 and 8 were much more active than Ketoconazole showing activity comparable to Abiraterone (IC(50) values of 90 and 52nM vs. 72nM). Most compounds also showed higher selectivities than Ketoconazole, but turned out to be less selective than Abiraterone. Docking studies using our CYP17 protein model were performed with selected compounds to study the interactions between the inhibitors and the amino acid residues of the active site.

Leishmanicidal compounds of Nectria pseudotrichia, an endophytic fungus isolated from the plant Caesalpinia echinata (Brazilwood).

PubMed

Cota, Betania Barros; Tunes, Luiza Guimarães; Maia, Daniela Nabak Bueno; Ramos, Jonas Pereira; Oliveira, Djalma Menezes de; Kohlhoff, Markus; Alves, Tânia Maria de Almeida; Souza-Fagundes, Elaine Maria; Campos, Fernanda Fraga; Zani, Carlos Leomar

2018-02-01

BACKGROUND In a screen of extracts from plants and fungi to detect antileishmanial activity, we found that the ethyl acetate extract of the fungus Nectria pseudotrichia, isolated from the tree Caesalpinia echinata (Brazilwood), is a promising source of bioactive compounds. OBJECTIVES The aims of this study were to isolate and determine the chemical structures of the compounds responsible for the antileishmanial activity of the organic extract from N. pseudotrichia. METHODS Compounds were isolated by chromatographic fractionation using semi-preparative high-performance liquid chromatography, and their chemical structures were determined by analytical and spectral data and by comparison with published data. The antileishmanial activity of the isolated compounds was evaluated in intracellular amastigote forms of Leishmania (Viannia) braziliensis expressing firefly luciferase as reporter gene, and cytotoxicity was determined in Vero and THP-1 mammalian cell lines by MTT assay. FINDINGS Fractionation of the extract yielded seven compounds: 10-acetyl trichoderonic acid A (1), 6'-acetoxy-piliformic acid (2), 5',6'-dehydropiliformic acid (3), piliformic acid (4), hydroheptelidic acid (5), xylaric acid D (6), and cytochalasin D (7). Compounds 1, 2 and 3 are reported here for the first time. Compounds 1, 2, and 5 were more active, with IC50 values of 21.4, 28.3, and 24.8 µM, respectively, and showed low toxicity to Vero and THP-1 cells. MAIN CONCLUSIONS N. pseudotrichia produces secondary metabolites that are more toxic to intracellular amastigote forms of L. (V.) braziliensis than to mammalian cells.

AMPK modulatory activity of olive-tree leaves phenolic compounds: Bioassay-guided isolation on adipocyte model and in silico approach.

PubMed

Jiménez-Sánchez, Cecilia; Olivares-Vicente, Mariló; Rodríguez-Pérez, Celia; Herranz-López, María; Lozano-Sánchez, Jesús; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Encinar, José Antonio; Micol, Vicente

2017-01-01

Olive-tree polyphenols have demonstrated potential for the management of obesity-related pathologies. We aimed to explore the capacity of Olive-tree leaves extract to modulate triglyceride accumulation and AMP-activated protein kinase activity (AMPK) on a hypertrophic adipocyte model. Intracellular triglycerides and AMPK activity were measured on the hypertrophic 3T3-L1 adipocyte model by AdipoRed and immunofluorescence microscopy, respectively. Reverse phase high performance liquid chromatography coupled to time-of-flight mass detection with electrospray ionization (RP-HPLC-ESI-TOF/MS) was used for the fractionation of the extract and the identification of the compounds. In-silico molecular docking of the AMPK alpha-2, beta and gamma subunits with the identified compounds was performed. Olive-tree leaves extract decreased the intracellular lipid accumulation through AMPK-dependent mechanisms in hypertrophic adipocytes. Secoiridoids, cinnamic acids, phenylethanoids and phenylpropanoids, flavonoids and lignans were the candidates predicted to account for this effect. Molecular docking revealed that some compounds may be AMPK-gamma modulators. The modulatory effects of compounds over the alpha and beta AMPK subunits appear to be less probable. Olive-tree leaves polyphenols modulate AMPK activity, which may become a therapeutic aid in the management of obesity-associated disturbances. The natural occurrence of these compounds may have important nutritional implications for the design of functional ingredients.

AMPK modulatory activity of olive–tree leaves phenolic compounds: Bioassay-guided isolation on adipocyte model and in silico approach

PubMed Central

Jiménez-Sánchez, Cecilia; Olivares-Vicente, Mariló; Rodríguez-Pérez, Celia; Herranz-López, María; Lozano-Sánchez, Jesús; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Encinar, José Antonio; Micol, Vicente

2017-01-01

Scope Olive-tree polyphenols have demonstrated potential for the management of obesity-related pathologies. We aimed to explore the capacity of Olive-tree leaves extract to modulate triglyceride accumulation and AMP-activated protein kinase activity (AMPK) on a hypertrophic adipocyte model. Methods Intracellular triglycerides and AMPK activity were measured on the hypertrophic 3T3-L1 adipocyte model by AdipoRed and immunofluorescence microscopy, respectively. Reverse phase high performance liquid chromatography coupled to time-of-flight mass detection with electrospray ionization (RP-HPLC-ESI-TOF/MS) was used for the fractionation of the extract and the identification of the compounds. In-silico molecular docking of the AMPK alpha-2, beta and gamma subunits with the identified compounds was performed. Results Olive-tree leaves extract decreased the intracellular lipid accumulation through AMPK-dependent mechanisms in hypertrophic adipocytes. Secoiridoids, cinnamic acids, phenylethanoids and phenylpropanoids, flavonoids and lignans were the candidates predicted to account for this effect. Molecular docking revealed that some compounds may be AMPK-gamma modulators. The modulatory effects of compounds over the alpha and beta AMPK subunits appear to be less probable. Conclusions Olive-tree leaves polyphenols modulate AMPK activity, which may become a therapeutic aid in the management of obesity-associated disturbances. The natural occurrence of these compounds may have important nutritional implications for the design of functional ingredients. PMID:28278224

Simultaneous optimization of the ultrasound-assisted extraction for phenolic compounds content and antioxidant activity of Lycium ruthenicum Murr. fruit using response surface methodology.

PubMed

Chen, Shasha; Zeng, Zhi; Hu, Na; Bai, Bo; Wang, Honglun; Suo, Yourui

2018-03-01

Lycium ruthenicum Murr. (LR) is a functional food that plays an important role in anti-oxidation due to its high level of phenolic compounds. This study aims to optimize ultrasound-assisted extraction (UAE) of phenolic compounds and antioxidant activities of obtained extracts from LR using response surface methodology (RSM). A four-factor-three-level Box-Behnken design (BBD) was employed to discuss the following extracting parameters: extraction time (X 1 ), ultrasonic power (X 2 ), solvent to sample ratio (X 3 ) and solvent concentration (X 4 ). The analysis of variance (ANOVA) results revealed that the solvent to sample ratio had a significant influence on all responses, while the extraction time had no statistically significant effect on phenolic compounds. The optimum values of the combination of phenolic compounds and antioxidant activities were obtained for X 1 =30min, X 2 =100W, X 3 =40mL/g, and X 4 =33% (v/v). Five phenolic acids, including chlorogenic acid, caffeic acid, syringic acid, p-coumaric acid and ferulic acid, were analyzed by HPLC. Our results indicated that optimization extraction is vital for the quantification of phenolic compounds and antioxidant activity in LR, which may be contributed to large-scale industrial applications and future pharmacological activities research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Balancing Antioxidant, Hypolipidemic and Anti-inflammatory Activity in a Single Agent: The Example of 2-Hydroxy-2-Substituted Morpholine, 1,4-Benzoxazine and 1,4-Benzothiazine Derivatives as a Rational Therapeutic Approach against Atherosclerosis.

PubMed

Matralis, Alexios N; Bavavea, Eugenia-Ismini; Incerpi, Sandra; Pedersen, Jens Z; Kourounakis, Angeliki P

2017-01-01

In line with our previous studies, novel morpholine and benzoxa(or thia)zine lead compounds have been developed through a rational design that modulate a multiplicity of targets against atherosclerosis. We have evaluated the most promising compounds for their efficiency to a) intercept and scavenge free radicals, b) inhibit the metal ion (Cu2+)- induced LDL oxidation c) act intracellularly as antioxidants in THP-1 monocytes from a leukemic patient and d) inhibit the pro-inflammatory enzymes cyclooxygenase-1 (COX-1) and -2 (COX-2) in vitro. Furthermore, two representative compounds were tested for their potential to decrease lipidemic parameters (TC, LDL and TG) in hyperlipidemic mice. Most derivatives indicated a remarkable antioxidant activity, while at the same time exhibited a significant in vitro anti-inflammatory activity, inhibiting COX-1 or/and COX-2 activity at 20 μΜ. In addition, after their long-term administration, compounds 6 and 8 afforded considerable activity in a chronic experimental animal model of hyperlipidemia (after high fat diet administration). The multifunctional pharmacological profile exhibited by the compounds of this study renders them interesting lead compounds for the development of novel agents against atherosclerosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Evaluation of hydrate-screening methods.

PubMed

Cui, Yong; Yao, Erica

2008-07-01

The purpose of this work is to evaluate the effectiveness and reliability of several common hydrate-screening techniques, and to provide guidelines for designing hydrate-screening programs for new drug candidates. Ten hydrate-forming compounds were selected as model compounds and six hydrate-screening approaches were applied to these compounds in an effort to generate their hydrate forms. The results prove that no screening approach is universally effective in finding hydrates for small organic compounds. Rather, a combination of different methods should be used to improve screening reliability. Among the approaches tested, the dynamic water vapor sorption/desorption isotherm (DVI) method and storage under high humidity (HH) yielded 60-70% success ratios, the lowest among all techniques studied. The risk of false negatives arises in particular for nonhygroscopic compounds. On the other hand, both slurry in water (Slurry) and temperature cycling of aqueous suspension (TCS) showed high success rates (90%) with some exceptions. The mixed solvent systems (MSS) procedure also achieved high success rates (90%), and was found to be more suitable for water-insoluble compounds. For water-soluble compounds, MSS may not be the best approach because recrystallization is difficult in solutions with high water activity. Finally, vapor diffusion (VD) yielded a reasonably high success ratio in finding hydrates (80%). However, this method suffers from experimental difficulty and unreliable results for either highly water-soluble or water-insoluble compounds. This study indicates that a reliable hydrate-screening strategy should take into consideration the solubility and hygroscopicity of the compounds studied. A combination of the Slurry or TCS method with the MSS procedure could provide a screening strategy with reasonable reliability.

Discovery of New Compounds Active against Plasmodium falciparum by High Throughput Screening of Microbial Natural Products.

PubMed

Pérez-Moreno, Guiomar; Cantizani, Juan; Sánchez-Carrasco, Paula; Ruiz-Pérez, Luis Miguel; Martín, Jesús; El Aouad, Noureddine; Pérez-Victoria, Ignacio; Tormo, José Rubén; González-Menendez, Víctor; González, Ignacio; de Pedro, Nuria; Reyes, Fernando; Genilloud, Olga; Vicente, Francisca; González-Pacanowska, Dolores

2016-01-01

Due to the low structural diversity within the set of antimalarial drugs currently available in the clinic and the increasing number of cases of resistance, there is an urgent need to find new compounds with novel modes of action to treat the disease. Microbial natural products are characterized by their large diversity provided in terms of the chemical complexity of the compounds and the novelty of structures. Microbial natural products extracts have been underexplored in the search for new antiparasitic drugs and even more so in the discovery of new antimalarials. Our objective was to find new druggable natural products with antimalarial properties from the MEDINA natural products collection, one of the largest natural product libraries harboring more than 130,000 microbial extracts. In this work, we describe the optimization process and the results of a phenotypic high throughput screen (HTS) based on measurements of Plasmodium lactate dehydrogenase. A subset of more than 20,000 extracts from the MEDINA microbial products collection has been explored, leading to the discovery of 3 new compounds with antimalarial activity. In addition, we report on the novel antiplasmodial activity of 4 previously described natural products.

Profile and antioxidant activity of phenolic extracts from 10 crabapples (Malus wild species).

PubMed

Li, Nan; Shi, Junling; Wang, Kun

2014-01-22

Phenolic products are highly demanded by the food and cosmetics industries and consumers due to their high antioxidant activities. To evaluate the potential of crabapples (Malus wild species) in preparing phenolic extracts, fruits of 10 crabapples grown in China were separately extracted with 80% (v/v) ethanol and ethyl acetate and the phenolic profiles, polyphenol (PC) and flavonoid contents (FC), and antioxidant activities of the extracts were analyzed. Chlorogenic acid, (-)-epicatechin, rutin, hyperin, and phlorizin appeared as the major phenolic compounds in all phenolic extracts. Ethanol extracts had PC of 302.83-1265.94 mg GAE/100g and FC of 352.45-2351.74 mg RE/100g, being 4.17 and 4.49 times those obtained in ethyl acetate extracts and much higher than those previously reported in apples. Malus wild species appeared as rich sources of phenolic compounds with high antioxidant activity, especially when high chlorogenic acid and rutin contents are emphasized.

Phenolic Compounds and Antioxidant Activity of Different Organs of Potentilla fruticosa L. from Two Main Production Areas of China.

PubMed

Yu, Danmeng; Pu, Wenjun; Li, Dengwu; Wang, Dongmei; Liu, Qiaoxiao; Wang, Yongtao

2016-09-01

This report compared the phenolic compounds and antioxidant activity of the leaves, flowers, and stems of Potentilla fruticosa L. collected from two main production areas of P. R. China (Taibai Mountains and the Qinghai Huzhu Northern Mountains). The results indicated that there were significant differences in the phenol contents and antioxidant activities among the different organs and between the two productions. High-performance liquid-chromatography analysis indicated that hyperoside, (+)-catechin, ellagic acid, and rutin were the primary compounds in leaves and flowers; for stems, the content of six phenolic compounds, from two productions, were the lowest. The 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt (ABTS), ferric reducing power (FRAP), lipid peroxidation assays, and microbial test system (MTS) were used to evaluate the antioxidant activity. The results demonstrated that the leaves from two productions exhibited powerful antioxidant activity than other organs, which did not significantly differ from that of the positive control (rutin), followed by the flowers and stems. The correlation between the content of phytochemicals and the antioxidant activities of different organs showed that the total phenol, tannin, hyperoside, and (+)-catechin contents may influence the antioxidant activity, and these compounds can be used as markers for the quality control of P. fruticosa. © 2016 Wiley-VHCA AG, Zürich.

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff base ligands: Synthesis, characterization and biocidal activities

NASA Astrophysics Data System (ADS)

Shabbir, Muhammad; Akhter, Zareen; Ashraf, Ahmad Raza; Ismail, Hammad; Habib, Anum; Mirza, Bushra

2017-12-01

Nickel(II) and palladium(II) triphenylphosphine complexes incorporating tridentate Schiff bases have been prepared and characterized by elemental analysis as well as by spectroscopic techniques (FTIR & NMR). The synthesized compounds were assessed to check their potential biocidal activity by using different biological assays (brine shrimp cytotoxicity, antimicrobial, antioxidant, antitumor and drug-DNA interaction). Results of brine shrimp cytotoxicity assay showed that ligand molecules are more bioactive than metal complexes with LD50 as low as 12.4 μg/mL. The prominent antitumor activity was shown by nickel complexes while the palladium complexes exhibited moderate activity. The synthesized compounds have shown high propensity for DNA binding either through intercalation or groove binding which represents the mechanism of antitumor effect of these compounds. Additionally, ligand molecules and nickel metal complexes showed significant antioxidant activity with IC50 values as low as 3.1 μg/mL and 18.9 μg/mL respectively while palladium complexes exhibited moderate activity. Moreover, in antimicrobial assays H2L1, Ni(L1)PPh3 and H2L3 showed dual inhibition against bacterial and fungal strains while for the rest of the compounds varying degree of activity was recorded against different strains. Overall comparison of results suggests that the synthesized compounds can be promising candidate for drug formulation and development.

Algicidal activity of marine Alteromonas sp. KNS-16 and isolation of active compounds.

PubMed

Cho, Ji Young

2012-01-01

The KNS-16 algicidal strain was isolated from a harmful alga bloom (HAB) area and identified as Alteromonas sp. based on 16S rDNA sequencing. The KNS-16 strain was found to control HABs by producing algicidal compounds in an indirect interaction. Four active compounds were isolated from KNS-16 culture, and their structures were analyzed by interpreting nuclear magnetic resonance and mass spectroscopy data. The structures were identified as 2-undecen-1'-yl-4-quinolone (1), 2-undecyl-4-quinolone (2), 3-hexyl-6-pentyl-4-hydroxyl-2H-pyran-2-one (3), and 6-heptyl-3-hexyl-4-hydroxyl-2H-pyran-2-one (4). Compound 1 was most active against HABs such as Heterosigma akashiwo, Cochlodinium polykrikoides, and Alexandrium tamarense with LC(50) values of 0.5-1.1 µg/mL. The four compounds exhibited high LC(50) values against aquaculture algae such as Tetaselmis suecica, Isochrysis galbana, and Pavlova lutheri at 39-66 µg/mL. Based on toxicity tests on the brine shrimp Artemia salina and the rotifer Brachionus rotundiformis, the four compounds showed ranges of 409-608 and 189-224 µg/mL of LC(50) for the two organisms, respectively. The LC(50) values for juvenile fish of Sebastes schlegelii were 284-304 µg/mL.

Synthesis and antioxidant activity of peptide-based ebselen analogues.

PubMed

Satheeshkumar, Kandhan; Mugesh, Govindasamy

2011-04-18

A series of di- and tripeptide-based ebselen analogues has been synthesized. The compounds were characterized by (1)H, (13)C, and (77)Se NMR spectroscopy and mass spectral techniques. The glutathione peroxidase (GPx)-like antioxidant activity has been studied by using H(2)O(2) , tert-butyl hydroperoxide (tBuOOH), and cumene hydroperoxide (Cum-OOH) as substrates, and glutathione (GSH) as a cosubstrate. Although all the peptide-based compounds have a selenazole ring similar to that of ebselen, the GPx activity of these compounds highly depends on the nature of the peptide moiety attached to the nitrogen atom of the selenazole ring. It was observed that the introduction of a phenylalanine (Phe) amino acid residue in the N-terminal reduces the activity in all three peroxide systems. On the other hand, the introduction of aliphatic amino acid residues such as valine (Val) significantly enhances the GPx activity of the ebselen analogues. The difference in the catalytic activity of dipeptide-based ebselen derivatives can be ascribed mainly to the change in the reactivity of these compounds toward GSH and peroxide. Although the presence of the Val-Ala-CO(2) Me moiety facilitates the formation of a catalytically active selenol species, the reaction of ebselen analogues that has a Phe-Ile-CO(2) Me residue with GSH does not generate the corresponding selenol. To understand the antioxidant activity of the peptide-based ebselen analogues in the absence of GSH, these compounds were studied for their ability to inhibit peroxynitrite (PN)-mediated nitration of bovine serum albumin (BSA) and oxidation of dihydrorhodamine 123. In contrast to the GPx activity, the PN-scavenging activity of the Phe-based peptide analogues was found to be comparable to that of the Val-based compounds. However, the introduction of an additional Phe residue to the ebselen analogue that had a Val-Ala dipeptide significantly reduced the potency of the parent compound in PN-mediated nitration. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pyridine sulfonamide as a small key organic molecule for the potential treatment of type-II diabetes mellitus and Alzheimer's disease: In vitro studies against yeast α-glucosidase, acetylcholinesterase and butyrylcholinesterase.

PubMed

Riaz, Sadaf; Khan, Islam Ullah; Bajda, Marek; Ashraf, Muhammad; Qurat-Ul-Ain; Shaukat, Ayesha; Rehman, Tanzeel Ur; Mutahir, Sadaf; Hussain, Sajjad; Mustafa, Ghulam; Yar, Muhammad

2015-12-01

This paper presents the efficient high yield synthesis of novel pyridine 2,4,6-tricarbohydrazide derivatives (4a-4i) along with their α-glucosidase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition activities. The enzymes inhibition results showed the potential of synthesized compounds in controlling both type-II diabetes mellitus and Alzheimer's disease. In vitro biological investigations revealed that most of compounds were more active against yeast α-glucosidase than the reference compound acarbose (IC50 38.25±0.12μM). Among the tested series the compound 4c bearing 4-flouro benzyl group was noted to be the most active (IC50 25.6±0.2μM) against α-glucosidase, and it displayed weak inhibition activities against AChE and BChE. Compound 4a exhibited the most desired results against all three enzymes, as it was significantly active against all the three enzymes; α-glucosidase (IC50 32.2±0.3μM), AChE (IC50 50.2±0.8μM) and BChE (IC50 43.8±0.8μM). Due to the most favorable activity of 4a against the tested enzymes, for molecular modeling studies this compound was selected to investigate its pattern of interaction with α-glucosidase and AChE targets. Copyright © 2015 Elsevier Inc. All rights reserved.

Structural Transformation Detection Contributes to Screening of Behaviorally Active Compounds: Dynamic Binding Process Analysis of DhelOBP21 from Dastarcus helophoroides.

PubMed

Yang, Rui-Nan; Li, Dong-Zhen; Yu, Guangqiang; Yi, Shan-Cheng; Zhang, Yinan; Kong, De-Xin; Wang, Man-Qun

2017-12-01

In light of reverse chemical ecology, the fluorescence competitive binding assays of functional odorant binding proteins (OBPs) is a recent advanced approach for screening behaviorally active compounds of insects. Previous research on Dastareus helophoroides identified a minus-C OBP, DhelOBP21, which preferably binds to several ligands. In this study, only (+)-β-pinene proved attractive to unmated adult beetles. To obtain a more in-depth explanation of the lack of behavioral activity of other ligands we selected compounds with high (camphor) and low (β-caryophyllene) binding affinities. The structural transformation of OBPs was investigated using well-established approaches for studying binding processes, such as fluorescent quenching assays, circular dichroism, and molecular dynamics. The dynamic binding process revealed that the flexibility of DhelOBP21 seems conducive to binding specific ligands, as opposed to broad substrate binding. The compound (+)-β-pinene and DhelOBP21 formed a stable complex through a secondary structural transformation of DhelOBP21, in which its amino-terminus transformed from random coil to an α-helix to cover the binding pocket. On the other hand, camphor could not efficiently induce a stable structural transformation, and its high binding affinities were due to strong hydrogen-bonding, compromising the structure of the protein. The other compound, β-caryophyllene, only collided with DhelOBP21 and could not be positioned in the binding pocket. Studying structural transformation of these proteins through examining the dynamic binding process rather than using approaches that just measure binding affinities such as fluorescence competitive binding assays can provide a more efficient and reliable approach for screening behaviorally active compounds.

Novel Antitubercular 6-Dialkylaminopyrimidine Carboxamides from Phenotypic Whole-Cell High Throughput Screening of a SoftFocus Library: Structure–Activity Relationship and Target Identification Studies

PubMed Central

2017-01-01

A BioFocus DPI SoftFocus library of ∼35 000 compounds was screened against Mycobacterium tuberculosis (Mtb) in order to identify novel hits with antitubercular activity. The hits were evaluated in biology triage assays to exclude compounds suggested to function via frequently encountered promiscuous mechanisms of action including inhibition of the QcrB subunit of the cytochrome bc1 complex, disruption of cell–wall homeostasis, and DNA damage. Among the hits that passed this screening cascade, a 6-dialkylaminopyrimidine carboxamide series was prioritized for hit to lead optimization. Compounds from this series were active against clinical Mtb strains, while no cross-resistance to conventional antituberculosis drugs was observed. This suggested a novel mechanism of action, which was confirmed by chemoproteomic analysis leading to the identification of BCG_3193 and BCG_3827 as putative targets of the series with unknown function. Initial structure–activity relationship studies have resulted in compounds with moderate to potent antitubercular activity and improved physicochemical properties. PMID:29148755

Synthesis of novel diarylamino-1,3,5-triazine derivatives as FAK inhibitors with anti-angiogenic activity.

PubMed

Dao, Pascal; Jarray, Rafika; Le Coq, Johanne; Lietha, Daniel; Loukaci, Ali; Lepelletier, Yves; Hadj-Slimane, Réda; Garbay, Christiane; Raynaud, Françoise; Chen, Huixiong

2013-08-15

We report herein the synthesis of novel diarylamino-1,3,5-triazine derivatives as FAK (focal adhesion kinase) inhibitors and the evaluation of their anti-angiogenic activity on HUVEC cells. Generally, the effects of these compounds on endothelial cells could be correlated with their kinase inhibitory activity. The most efficient compounds displayed inhibition of viability against HUVEC cells in the micromolar range, as observed with TAE-226, which was designed by Novartis Pharma AG. X-ray crystallographic analysis of the co-crystal structure for compound 34 revealed that the mode of interaction with the FAK kinase domain is highly similar to that observed in the complex of TAE-226. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assay development and case history of a 32K-biased library high-content MK2-EGFP translocation screen to identify p38 mitogen-activated protein kinase inhibitors on the ArrayScan 3.1 imaging platform.

PubMed

Trask, Oscar J; Baker, Audrey; Williams, Rhonda Gates; Nickischer, Debra; Kandasamy, Ramani; Laethem, Carmen; Johnston, Patricia A; Johnston, Paul A

2006-01-01

This chapter describes the conversion and assay development of a 96-well MK2-EGFP translocation assay into a higher density 384-well format high-content assay to be screened on the ArrayScan 3.1 imaging platform. The assay takes advantage of the well-substantiated hypothesis that mitogen-activated protein kinase-activating protein kinase-2 (MK2) is a substrate of p38 MAPK kinase and that p38-induced phosphorylation of MK-2 induces a nucleus-to-cytoplasm translocation. This chapter also presents a case history of the performance of the MK2-EGFP translocation assay, run as a "high-content" screen of a 32K kinase-biased library to identify p38 inhibitors. The assay performed very well and a number of putative p38 inhibitor hits were identified. Through the use of multiparameter data provided by the nuclear translocation algorithm and by checking images, a number of compounds were identified that were potential artifacts due to interference with the imaging format. These included fluorescent compounds, or compounds that dramatically reduced cell numbers due to cytotoxicity or by disrupting cell adherence. A total of 145 compounds produced IC(50) values <50.0 muM in the MK2-EGFP translocation assay, and a cross target query of the Lilly-RTP HTS database confirmed their inhibitory activity against in vitro kinase targets, including p38a. Compounds were confirmed structurally by LCMS analysis and profiled in cell-based imaging assays for MAPK signaling pathway selectivity. Three of the hit scaffolds identified in the MK2-EGFP translocation HCS run on the ArrayScan were selected for a p38a inhibitor hit-to-lead structure activity relationship (SAR) chemistry effort.

Assessment of the DNA damaging potential of environmental chemicals using a quantitative high-throughput screening approach to measure p53 activation.

PubMed

Witt, Kristine L; Hsieh, Jui-Hua; Smith-Roe, Stephanie L; Xia, Menghang; Huang, Ruili; Zhao, Jinghua; Auerbach, Scott S; Hur, Junguk; Tice, Raymond R

2017-08-01

Genotoxicity potential is a critical component of any comprehensive toxicological profile. Compounds that induce DNA or chromosomal damage often activate p53, a transcription factor essential to cell cycle regulation. Thus, within the US Tox21 Program, we screened a library of ∼10,000 (∼8,300 unique) environmental compounds and drugs for activation of the p53-signaling pathway using a quantitative high-throughput screening assay employing HCT-116 cells (p53 +/+ ) containing a stably integrated β-lactamase reporter gene under control of the p53 response element (p53RE). Cells were exposed (-S9) for 16 hr at 15 concentrations (generally 1.2 nM to 92 μM) three times, independently. Excluding compounds that failed analytical chemistry analysis or were suspected of inducing assay interference, 365 (4.7%) of 7,849 unique compounds were concluded to activate p53. As part of an in-depth characterization of our results, we first compared them with results from traditional in vitro genotoxicity assays (bacterial mutation, chromosomal aberration); ∼15% of known, direct-acting genotoxicants in our library activated the p53RE. Mining the Comparative Toxicogenomics Database revealed that these p53 actives were significantly associated with increased expression of p53 downstream genes involved in DNA damage responses. Furthermore, 53 chemical substructures associated with genotoxicity were enriched in certain classes of p53 actives, for example, anthracyclines (antineoplastics) and vinca alkaloids (tubulin disruptors). Interestingly, the tubulin disruptors manifested unusual nonmonotonic concentration response curves suggesting activity through a unique p53 regulatory mechanism. Through the analysis of our results, we aim to define a role for this assay as one component of a comprehensive toxicological characterization of large compound libraries. Environ. Mol. Mutagen. 58:494-507, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Radical scavenging activity and LC-MS metabolic profiling of petals, stamens, and flowers of Crocus sativus L.

PubMed

Montoro, Paola; Maldini, Mariateresa; Luciani, Leonilda; Tuberoso, Carlo I G; Congiu, Francesca; Pizza, Cosimo

2012-08-01

Radical scavenging activities of Crocus sativus petals, stamens and entire flowers, which are waste products in the production of the spice saffron, by employing ABTS radical scavenging method, were determined. At the same time, the metabolic profiles of different extract (obtained by petals, stamens and flowers) were obtained by LC-ESI-IT MS (liquid chromatography coupled with electrospray mass spectrometry equipped with Ion Trap analyser). LC-ESI-MS is a techniques largely used nowadays for qualitative fingerprint of herbal extracts and particularly for phenolic compounds. To compare the different extracts under an analytical point of view a specific method for qualitative LC-MS analysis was developed. The high variety of glycosylated flavonoids found in the metabolic profiles could give value to C. sativus petals, stamens and entire flowers. Waste products obtained during saffron production, could represent an interesting source of phenolic compounds, with respect to the high variety of compounds and their free radical scavenging activity. © 2012 Institute of Food Technologists®

High-Throughput Assay and Discovery of Small Molecules that Interrupt Malaria Transmission

PubMed Central

Plouffe, David M.; Wree, Melanie; Du, Alan Y.; Meister, Stephan; Li, Fengwu; Patra, Kailash; Lubar, Aristea; Okitsu, Shinji L.; Flannery, Erika L.; Kato, Nobutaka; Tanaseichuk, Olga; Comer, Eamon; Zhou, Bin; Kuhen, Kelli; Zhou, Yingyao; Leroy, Didier; Schreiber, Stuart L.; Scherer, Christina A.; Vinetz, Joseph; Winzeler, Elizabeth A.

2016-01-01

Summary Preventing transmission is an important element of malaria control. However, most of the current available methods to assay for malaria transmission blocking are relatively low throughput and cannot be applied to large chemical libraries. We have developed a high-throughput and cost-effective assay, the Saponin-lysis Sexual Stage Assay (SaLSSA), for identifying small molecules with transmission-blocking capacity. SaLSSA analysis of 13,983 unique compounds uncovered that >90% of well-characterized antimalarials, including endoperoxides and 4-aminoquinolines, as well as compounds active against asexual blood stages, lost most of their killing activity when parasites developed into metabolically quiescent stage V gametocytes. On the other hand, we identified compounds with consistent low nanomolar transmission-blocking activity, some of which showed cross-reactivity against asexual blood and liver stages. The data clearly emphasize substantial physiological differences between sexual and asexual parasites and provide a tool and starting points for the discovery and development of transmission-blocking drugs. PMID:26749441

Identification of Compounds with Anti-Proliferative Activity against Trypanosoma brucei brucei Strain 427 by a Whole Cell Viability Based HTS Campaign

PubMed Central

Kaiser, Marcel; Chatelain, Eric; Moawad, Sarah R.; Ganame, Danny; Ioset, Jean-Robert; Avery, Vicky M.

2012-01-01

Human African Trypanosomiasis (HAT) is caused by two trypanosome sub-species, Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense. Drugs available for the treatment of HAT have significant issues related to difficult administration regimes and limited efficacy across species and disease stages. Hence, there is considerable need to find new alternative and less toxic drugs. An approach to identify starting points for new drug candidates is high throughput screening (HTS) of large compound library collections. We describe the application of an Alamar Blue based, 384-well HTS assay to screen a library of 87,296 compounds against the related trypanosome subspecies, Trypanosoma brucei brucei bloodstream form lister 427. Primary hits identified against T.b. brucei were retested and the IC50 value compounds were estimated for T.b. brucei and a mammalian cell line HEK293, to determine a selectivity index for each compound. The screening campaign identified 205 compounds with greater than 10 times selectivity against T.b. brucei. Cluster analysis of these compounds, taking into account chemical and structural properties required for drug-like compounds, afforded a panel of eight compounds for further biological analysis. These compounds had IC50 values ranging from 0.22 µM to 4 µM with associated selectivity indices ranging from 19 to greater than 345. Further testing against T.b. rhodesiense led to the selection of 6 compounds from 5 new chemical classes with activity against the causative species of HAT, which can be considered potential candidates for HAT early drug discovery. Structure activity relationship (SAR) mining revealed components of those hit compound structures that may be important for biological activity. Four of these compounds have undergone further testing to 1) determine whether they are cidal or static in vitro at the minimum inhibitory concentration (MIC), and 2) estimate the time to kill. PMID:23209849

Phenolic acids, hydrolyzable tannins, and antioxidant activity of geopropolis from the stingless bee Melipona fasciculata Smith.

PubMed

Dutra, Richard Pereira; Abreu, Bruno Vinicius de Barros; Cunha, Mayara Soares; Batista, Marisa Cristina Aranha; Torres, Luce Maria Brandão; Nascimento, Flavia Raquel Fernandes; Ribeiro, Maria Nilce Sousa; Guerra, Rosane Nassar Meireles

2014-03-26

Geopropolis is a mixture of plant resins, waxes, and soil produced by the stingless bee Melipona fasciculata Smith. This paper describes the antioxidant activity and chemical composition of geopropolis produced by M. fasciculata. The total phenolic content determined with the Folin-Ciocalteu reagent was highest in the ethyl acetate fraction and hydroalcoholic extract. Antioxidant activity was assayed by the in vitro DPPH, ABTS, and FRAP assays. The hydroalcoholic extract and fractions of geopropolis, except for the hexane fraction, exhibited antioxidant activity against DPPH, ABTS, and FRAP. The phenolic compounds were identified by HPLC-DAD-MS on the basis of the evaluation of their UV-vis absorption maxima (λmax) and mass spectral analysis. Eleven compounds belonging to the classes of phenolic acids and hydrolyzable tannins (gallotannins and ellagitannins) were tentatively identified. These compounds are responsible for the antioxidant activity and high phenolic content of geopropolis produced by M. fasciculata.

Synthesis, fungicidal evaluation and 3D-QSAR studies of novel 1,3,4-thiadiazole xylofuranose derivatives

PubMed Central

Zong, Guanghui; Yan, Xiaojing; Bi, Jiawei; Jiang, Rui; Qin, Yinan; Yuan, Huizhu; Lu, Huizhe; Dong, Yanhong; Jin, Shuhui; Zhang, Jianjun

2017-01-01

1,3,4-Thiadiazole and sugar-derived molecules have proven to be promising agrochemicals with growth promoting, insecticidal and fungicidal activities. In the research field of agricultural fungicide, applying union of active group we synthesized a new set of 1,3,4-thiadiazole xylofuranose derivatives and all of the compounds were characterized by 1H NMR and HRMS. In precise toxicity measurement, some of compounds exhibited more potent fungicidal activities than the most widely used commercial fungicide Chlorothalonil, promoting further research and development. Based on our experimental data, 3D-QSAR (three-dimensional quantitative structure-activity relationship) was established and investigated using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) techniques, helping to better understand the structural requirements of lead compounds with high fungicidal activity and environmental compatibility. PMID:28746366

Different phenolic compounds activate distinct human bitter taste receptors.

PubMed

Soares, Susana; Kohl, Susann; Thalmann, Sophie; Mateus, Nuno; Meyerhof, Wolfgang; De Freitas, Victor

2013-02-20

Bitterness is a major sensory attribute of several common foods and beverages rich in polyphenol compounds. These compounds are reported as very important for health as chemopreventive compounds, but they are also known to taste bitter. In this work, the activation of the human bitter taste receptors, TAS2Rs, by six polyphenol compounds was analyzed. The compounds chosen are present in a wide range of plant-derived foods and beverages, namely, red wine, beer, tea, and chocolate. Pentagalloylglucose (PGG) is a hydrolyzable tannin, (-)-epicatechin is a precursor of condensed tannins, procyanidin dimer B3 and trimer C2 belong to the condensed tannins, and malvidin-3-glucoside and cyanidin-3-glucoside are anthocyanins. The results show that the different compounds activate different combinations of the ~25 TAS2Rs. (-)-Epicatechin activated three receptors, TAS2R4, TAS2R5, and TAS2R39, whereas only two receptors, TAS2R5 and TAS2R39, responded to PGG. In contrast, malvidin-3-glucoside and procyanidin trimer stimulated only one receptor, TAS2R7 and TAS2R5, respectively. Notably, tannins are the first natural agonists found for TAS2R5 that display high potency only toward this receptor. The catechol and/or galloyl groups appear to be important structural determinants that mediate the interaction of these polyphenolic compounds with TAS2R5. Overall, the EC(50) values obtained for the different compounds vary 100-fold, with the lowest values for PGG and malvidin-3-glucoside compounds, suggesting that they could be significant polyphenols responsible for the bitterness of fruits, vegetables, and derived products even if they are present in very low concentrations.

Influence of physicochemical characteristics and high pressure processing on the volatile fraction of Iberian dry-cured ham.

PubMed

Martínez-Onandi, Nerea; Rivas-Cañedo, Ana; Ávila, Marta; Garde, Sonia; Nuñez, Manuel; Picon, Antonia

2017-09-01

The volatile fraction of 30 Iberian dry-cured hams of different physicochemical characteristics and the effect of high pressure processing (HPP) at 600MPa on volatile compounds were investigated. According to the analysis of variance carried out on the levels of 122 volatile compounds, intramuscular fat content influenced the levels of 8 benzene compounds, 5 carboxylic acids, 2 ketones, 2 furanones, 1 alcohol, 1 aldehyde and 1 sulfur compound, salt concentration influenced the levels of 1 aldehyde and 1 ketone, salt-in-lean ratio had no effect on volatile compounds, and water activity influenced the levels of 3 sulfur compounds, 1 alcohol and 1 aldehyde. HPP-treated samples of Iberian ham had higher levels of 4 compounds and lower levels of 31 compounds than untreated samples. A higher influence of HPP treatment on volatile compounds than physicochemical characteristics was observed for Iberian ham. Therefore, HPP treatment conditions should be optimized in order to diminish its possible effect on Iberian ham odor and aroma characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-trypanosomal activity of pentacyclic triterpenes isolated from Austroplenckia populnea (Celastraceae).

PubMed

Duarte, Lucienir Pains; Vieira Filho, Sidney Augusto; Silva, Grácia Divina de Fátima; de Sousa, José Rego; Pinto, Artur da Silveira

2002-01-01

Four pentacyclic triterpenes isolated from Austroplenckia populnea and four compounds of known anti T. cruzi or anti-malarial activity were tested. Of those triterpenes tested 20alpha-hydroxy-tingenone showed high activity, epikatonic acid was less active, while populnilic and populninic acids were inactive against the trypanosome of the subgenus Schizotrypanum tested. Benzonidazole, nifurtimox, ketoconazole and primaquine presented a remarkable dose-dependent inhibitory effect reaching practically to a total growth inhibition of the parasite at the end of incubation time. The trypanosome tested appear to be a suitable model for preliminary screen for anti T. (S.) cruzi compounds.

Microwave-assisted synthesis, structural characterization, DFT studies, antibacterial and antioxidant activity of 2-methyl-4-oxo-1,2,3,4-tetrahydroquinazoline-2-carboxylic acid

NASA Astrophysics Data System (ADS)

Obafemi, Craig A.; Fadare, Olatomide A.; Jasinski, Jerry P.; Millikan, Sean P.; Obuotor, Efere M.; Iwalewa, Ezekiel O.; Famuyiwa, Samson O.; Sanusi, Kayode; Yilmaz, Yusuf; Ceylan, Ümit

2018-03-01

In the present study a new tetrahydroquinazoline-2-carboxylic, C10H10N2O3, 1‧, was synthesized and its structure was characterized by elemental analysis, IR, 1H NMR, 13C NMR data and high-resolution mass spectrometry. The spectral results are in line with the proposed structure. Single crystal X-ray structural analysis of the compound showed that the crystal structure adopts a monoclinic space group P21/c, with the packing of the molecule stabilized by Cdbnd O … …Hsbnd O, Nsbnd H … ….Odbnd Csbnd Osbnd intermolecular hydrogen bonding. The theoretical geometrical parameters of the compound have been calculated using density functional (DFT) and time-dependent density functional (TD-DFT) theory methods and have been used to predict the thermodynamic one-electron redox potential and the electronic absorption property of the compound. The theoretical characterization matched the experimental measurements, showing a good correlation. The calculated HOMO-LUMO gap (4.79 eV) suggests that compound 1‧ could be a potential antioxidant. The synthesized compound was screened for its in vitro antimicrobial activity against selected bacterial strains and antioxidant activity using the TAC, FRAP, NO and ABTS models. In vitro antioxidant activity of 1' showed a moderate activity, but weaker scavenging activity than the standards of ascorbic acid and trolox. Results of the antibacterial activity of the tested compound showed that it possesses a higher activity against Bacillus anthracis, Bacillus cereus, Bacillus polymyxa, Bacillus subtilis and Staphylococcus aureus than the two standard drugs, streptomycin and tetracycline, and better activity than tetracycline against Escherichia coli.

Analysis of phytochemical profile of Terminalia arjuna bark extract with antioxidative and antimicrobial properties.

PubMed

Mandal, Shreya; Patra, Arpita; Samanta, Animesh; Roy, Suchismita; Mandal, Arpita; Mahapatra, Tapasi Das; Pradhan, Shrabani; Das, Koushik; Nandi, Dilip Kumar

2013-12-01

To investigate phytochemical screening, antimicrobial activity and qualitative thin layer chromatographic separation of flavonoid components, antioxidant activity and total flavonoid compound of Terminalia arjuna. For phytochemical screening, some common and available standard tests were done. Antimicrobial bioassay was done through agar well diffusion method. Detection of antioxidant activity and flavonoid compounds were done through thin layer chromatography. Total antioxidant activity was measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) in colorimetric method. Aluminum chloride colorimetric method was used for total flavonoid determination. Phytochemical screening showed the active compounds presence in high concentration, such as phytosterol, lactones, flavonoids, phenolic compounds and tannins and glycosides. The antimicrobial activity of extract showed that greater inhibition zone against Gram negative bacteria than Gram positive bacteria. This methanolic extract showed a promising antioxidant activity, as absorption of DPPH redicles decreased in DPPH free radical scavenging assay. Flavonoids components having antioxidant property present in the methanol extract at a level of 199.00 mg quercetin equivalent/g of dried methanol extract in colorimetric method. The Terminalia arjuna bark extract revealed the presence of bio-active constituents which are known to exhibit medicinal as well as physiological activities. Copyright © 2013 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.

Trypanosoma Cruzi Cyp51 Inhibitor Derived from a Mycobacterium Tuberculosis Screen Hit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Chiung-Kuang; Doyle, Patricia S.; Yermalitskaya, Liudmila V.

2009-02-18

The two front-line drugs for chronic Trypanosoma cruzi infections are limited by adverse side-effects and declining efficacy. One potential new target for Chagas disease chemotherapy is sterol 14{alpha}-demethylase (CYP51), a cytochrome P450 enzyme involved in biosynthesis of membrane sterols. In a screening effort targeting Mycobacterium tuberculosis CYP51 (CYP51{sub Mt}), we previously identified the N-[4-pyridyl]-formamide moiety as a building block capable of delivering a variety of chemotypes into the CYP51 active site. In that work, the binding modes of several second generation compounds carrying this scaffold were determined by high-resolution co-crystal structures with CYP51{sub Mt}. Subsequent assays against the CYP51 orthologuemore » in T. cruzi, CYP51{sub Tc}, demonstrated that two of the compounds tested in the earlier effort bound tightly to this enzyme. Both were tested in vitro for inhibitory effects against T. cruzi and the related protozoan parasite Trypanosoma brucei, the causative agent of African sleeping sickness. One of the compounds had potent, selective anti-T. cruzi activity in infected mouse macrophages. Cure of treated host cells was confirmed by prolonged incubation in the absence of the inhibiting compound. Discrimination between T. cruzi and T. brucei CYP51 by the inhibitor was largely based on the variability (phenylalanine versus isoleucine) of a single residue at a critical position in the active site. CYP51{sub Mt}-based crystal structure analysis revealed that the functional groups of the two tightly bound compounds are likely to occupy different spaces in the CYP51 active site, suggesting the possibility of combining the beneficial features of both inhibitors in a third generation of compounds to achieve more potent and selective inhibition of CYP51{sub Tc}. Enzyme sterol 14{alpha}-demethylase (CYP51) is a well-established target for anti-fungal therapy and is a prospective target for Chagas disease therapy. We previously identified a chemical scaffold capable of delivering a variety of chemical structures into the CYP51 active site. In this work the binding modes of several second generation compounds carrying this scaffold were determined in high-resolution co-crystal structures with CYP51 of Mycobacterium tuberculosis. Subsequent assays against CYP51 in Trypanosoma cruzi, the agent of Chagas disease, demonstrated that two of the compounds bound tightly to the enzyme. Both were tested for inhibitory effects against T. cruzi and the related protozoan parasite Trypanosoma brucei. One of the compounds had potent, selective anti-T. cruzi activity in infected mouse macrophages. This compound is currently being evaluated in animal models of Chagas disease. Discrimination between T. cruzi and T. brucei CYP51 by the inhibitor was largely based on the variability of a single amino acid residue at a critical position in the active site. Our work is aimed at rational design of potent and highly selective CYP51 inhibitors with potential to become therapeutic drugs. Drug selectivity to prevent host-pathogen cross-reactivity is pharmacologically important, because CYP51 is present in human host.« less

Syzygium cumini is more effective in preventing the increase of erythrocytic ADA activity than phenolic compounds under hyperglycemic conditions in vitro.

PubMed

De Bona, Karine S; Bonfanti, Gabriela; Bitencourt, Paula E R; Cargnelutti, Lariane O; da Silva, Priscila S; da Silva, Thainan P; Zanette, Régis A; Pigatto, Aline S; Moretto, Maria B

2014-06-01

Syzygium cumini (S. cumini) is a plant known for its antidiabetic properties. The aim of this study was to evaluate the effect of Sc aqueous leaf extract (ASc) on adenosine deaminase (ADA) activity in erythrocytes (RBCs) exposed to high glucose concentrations (30 mM) in vitro. We also investigated the effects of the main phenolic compounds found in ASc (gallic acid, rutin, and chlorogenic acid) and the effects of insulin, caffeine, and dipyridamole, which are substances involved in the adenosine metabolism, on ADA activity in vitro. Blood samples were obtained from healthy volunteers and a suspension of RBCs was used for the determination of ADA activity. The results showed that: (1) the effect of ASc on ADA activity was more significant than the combination of phenolic compounds; (2) insulin, caffeine, or dipyridamole prevented high glucose increase of ADA activity at doses as low as 50 μU/mL, 25 μM, and 1 μM, respectively; (3) the inhibitory effect caused by ASc on erythrocyte ADA activity remained practically the same after the combination of the extract with insulin or caffeine; (4) when RBCs were exposed to ASc plus dipyridamole, this chemical attenuated the effect of ASc on ADA activity, suggesting an antagonism or a competition with ASc by the same site of action. Therefore, ASc was more effective in preventing the increase in ADA activity than phenolic compounds, suggesting that ASc may collaborate to improve endothelial dysfunction, antioxidant, anti-inflammatory, and antithrombotic properties of adenosine by affecting its metabolism. The results of this study help to provide evidence of the empirically supported benefits of the use of S. cumini in diabetes.

Towards a high yield recovery of polyphenols from olive mill wastewater on activated carbon coated with milk proteins: Experimental design and antioxidant activity.

PubMed

Yangui, Asma; Abderrabba, Manef

2018-10-01

Activated carbon coated with milk proteins was used for the removal and recovery of phenolic compounds from actual olive mill wastewater (OMW). The extraction of polyphenols using the new adsorbent based on natural coating agent has significant potential compared with traditional extraction methods, as it significantly increases the extraction yield (80%) and overall efficiencies of the process for total phenols (75.4%) and hydroxytyrosol (90.6%) which is the most valuable compound. Complete discussions on the adsorption isotherms, kinetic and thermodynamic were performed and the optimum adsorption variables were investigated using the response surface methodology and the central composite experimental design. The extracted polyphenols exhibited a high antioxidant activity and a fast scavenging effect on DPPH free radical. The strategy devised in this work for polyphenol extraction using modified activated carbon with biological coating agent is of simple design, very effective and ensure the recovery of highly antioxidant extract. Copyright © 2018 Elsevier Ltd. All rights reserved.

Target specific compound identification using a support vector machine.

PubMed

Plewczynski, Dariusz; von Grotthuss, Marcin; Spieser, Stephane A H; Rychlewski, Leszek; Wyrwicz, Lucjan S; Ginalski, Krzysztof; Koch, Uwe

2007-03-01

In many cases at the beginning of an HTS-campaign, some information about active molecules is already available. Often known active compounds (such as substrate analogues, natural products, inhibitors of a related protein or ligands published by a pharmaceutical company) are identified in low-throughput validation studies of the biochemical target. In this study we evaluate the effectiveness of a support vector machine applied for those compounds and used to classify a collection with unknown activity. This approach was aimed at reducing the number of compounds to be tested against the given target. Our method predicts the biological activity of chemical compounds based on only the atom pairs (AP) two dimensional topological descriptors. The supervised support vector machine (SVM) method herein is trained on compounds from the MDL drug data report (MDDR) known to be active for specific protein target. For detailed analysis, five different biological targets were selected including cyclooxygenase-2, dihydrofolate reductase, thrombin, HIV-reverse transcriptase and antagonists of the estrogen receptor. The accuracy of compound identification was estimated using the recall and precision values. The sensitivities for all protein targets exceeded 80% and the classification performance reached 100% for selected targets. In another application of the method, we addressed the absence of an initial set of active compounds for a selected protein target at the beginning of an HTS-campaign. In such a case, virtual high-throughput screening (vHTS) is usually applied by using a flexible docking procedure. However, the vHTS experiment typically contains a large percentage of false positives that should be verified by costly and time-consuming experimental follow-up assays. The subsequent use of our machine learning method was found to improve the speed (since the docking procedure was not required for all compounds from the database) and also the accuracy of the HTS hit lists (the enrichment factor).

Antiretroviral Activity Of a Novel Pyrimidyl-Di(Diazaspiroalkane) Derivative

PubMed Central

Novoselova, E.A.; Riabova, O.B.; Leneva, I.A.; Nesterenko, V.G.; Bolgarin, R.N.; Makarov, V.A.

2017-01-01

A novel compound, 3,3’-(5-nitropyrimidine-4,6-diyl)bis-3,12-diaza-6,9-diazoniadispiro[5.2.5.2]hexadecane tetrachloride dihydrochloride, was synthesized. The compound was found to inhibit the replication of various viral families by blocking specific heparan sulfate receptors on the host cell’s surface. In experiments, the compound was found to be highly effective against several strains of HIV retroviruses. PMID:28461981

Use of advanced techniques for the extraction of phenolic compounds from Tunisian olive leaves: phenolic composition and cytotoxicity against human breast cancer cells.

PubMed

Taamalli, Amani; Arráez-Román, David; Barrajón-Catalán, Enrique; Ruiz-Torres, Verónica; Pérez-Sánchez, Almudena; Herrero, Miguel; Ibañez, Elena; Micol, Vicente; Zarrouk, Mokhtar; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

2012-06-01

A comparison among different advanced extraction techniques such as microwave-assisted extraction (MAE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), together with traditional solid-liquid extraction, was performed to test their efficiency towards the extraction of phenolic compounds from leaves of six Tunisian olive varieties. Extractions were carried out at the best selected conditions for each technique; the obtained extracts were chemically characterized using high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap tandem mass spectrometry (ESI-IT-MS(2)). As expected, higher extraction yields were obtained for PLE while phenolic profiles were mainly influenced by the solvent used as optimum in the different extraction methods. A larger number of phenolic compounds, mostly of a polar character, were found in the extracts obtained by using MAE. Best extraction yields do not correlate with highest cytotoxic activity against breast cancer cells, indicating that cytotoxicity is highly dependent on the presence of certain compounds in the extracts, although not exclusively on a single compound. Therefore, a multifactorial behavior is proposed for the anticancer activity of olive leaf compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effective adsorption of phenolic compound from aqueous solutions on activated semi coke

NASA Astrophysics Data System (ADS)

Gao, Xiaoming; Dai, Yuan; Zhang, Yu; Fu, Feng

2017-03-01

Activated Semi coke was prepared by KOH activation and employed as adsorbent to study adsorption function of phenolic compound from aqueous solutions. The adsorption result showed that the adsorption capacity of the activated semi coke for phenolic compound increased with contact time and adsorbent dosage, and slightly affected by temperature. The surface structure property of the activated semi coke was characterized by N2 adsorption, indicating that the activated semi coke was essentially macroporous, and the BET surface area was 347.39 m2 g-1. Scanning electron microscopy indicated that the surface of the activated semi coke had a high developed pore. The adsorption kinetics were investigated according to pseudofirst order, pseudosecond order and intraparticle diffusion, and the kinetics data were fitted by pseudosecond order model, and intraparticle diffusion was not the only rate-controlling step. Adsorption isotherm was studied by Langmuir, Freundlich, Temkin, Redlich-Peterson, Sips and Toth models. The result indicated that adsorption isotherm data could fit well with Langmuir, Redlich-Peterson, Sips and Toth models.

Regioselective synthesis of 3-benzyl substituted pyrimidino chromen-2-ones and evaluation of anti-microbial and anti-biofilm activities.

PubMed

Emmadi, Narender Reddy; Atmakur, Krishnaiah; Bingi, Chiranjeevi; Godumagadda, Narender Reddy; Chityal, Ganesh Kumar; Nanubolu, Jagadeesh Babu

2014-01-15

Regioselective synthesis of a number of highly functionalized 3-benzylpyrimidino chromen-2-ones (4) were accomplished in a one pot three component reaction in acetic acid and determined their anti-microbial and anti-biofilm activities. Compounds 4o and 4p showed an excellent anti-microbial activity against Micrococcus luteus MTCC 2470 at a par with standard control (Ciprofloxacin) and exhibited best activity against Staphylococcus aureus MTCC 96 and Bacillus subtilis MTCC 121. Further, compounds 4h, 4i, 4m, 4n and 4q showed promising activity against Micrococcus luteus MTCC 2470, Staphylococcus aureus MTCC 96 and Bacillus subtilis MTCC 121. Whereas, compounds 4m showed very promising biofilm inhibition activity against Staphylococcus aureus MLS 16 MTCC 2940 and 4o, 4p showed very potent activity against Staphylococcus aureus MTCC 96 at a par with Ciprofloxacin used as standard control. Copyright © 2013 Elsevier Ltd. All rights reserved.

Detection of Aryl Hydrocarbon Receptor Activation by Some Chemicals in Food Using a Reporter Gene Assay

PubMed Central

Amakura, Yoshiaki; Tsutsumi, Tomoaki; Yoshimura, Morio; Nakamura, Masafumi; Handa, Hiroshi; Matsuda, Rieko; Teshima, Reiko; Watanabe, Takahiro

2016-01-01

The purpose of this study was to examine whether a simple bioassay used for the detection of dioxins (DXNs) could be applied to detect trace amounts of harmful DXN-like substances in food products. To identify substances with possible DXN-like activity, we assessed the ability of various compounds in the environment to bind the aryl hydrocarbon receptor (AhR) that binds specifically to DXNs. The compounds tested included 19 polycyclic aromatic hydrocarbons (PAHs), 20 PAH derivatives (nitrated, halogenated, and aminated derivatives), 23 pesticides, six amino acids, and eight amino acid metabolites. The AhR binding activities (AhR activity) of these compounds were measured using the chemical activated luciferase gene expression (CALUX) reporter gene assay system. The majority of the PAHs exhibited marked AhR activity that increased in a concentration-dependent manner. Furthermore, there was a positive link between AhR activity and the number of aromatic rings in the PAH derivatives. Conversely, there appeared to be a negative correlation between AhR activity and the number of chlorine residues present on halogenated PAH derivatives. However, there was no correlation between AhR activity and the number and position of substituents among nitrated and aminated derivatives. Among the pesticides tested, the indole-type compounds carbendazim and thiabendazole showed high levels of activity. Similarly, the indole compound tryptamine was the only amino acid metabolite to induce AhR activity. The results are useful in understanding the identification and characterization of AhR ligands in the CALUX assay. PMID:28231110

Benzoin Schiff Bases: Design, Synthesis, and Biological Evaluation as Potential Antitumor Agents.

PubMed

Sabbah, Dima A; Al-Tarawneh, Fatima; Talib, Wamidh H; Sweidan, Kamal; Bardaweel, Sanaa K; Al-Shalabi, Eveen; Zhong, Haizhen A; Abu Sheikha, Ghassan; Abu Khalaf, Reema; Mubarak, Mohammad S

2018-04-12

Phosphoinositide 3-kinase α (PI3Kα) is an attractive target for anticancer drug design. Target compounds were designed to probe the significance of alcohol and imine moieties tailored on a benzoin scaffold to better understand the structure activity relation (SAR) and improve their biological activity as anticancer compounds. Chemical synthesis of the targeted compounds, biological evaluation tests against human colon adenocarcinoma (HCT-116), breast adenocarcinoma (MCF-7), and breast carcinoma (T47D) cell lines, as well as Glide docking studies were employed in this investigation. A new series of 1,2-diphenylimino ethanol was successfully synthesized and characterized by means of FT-IR, HRMS, NMR, and by elemental analysis. Biological screening revealed that the newly synthesized compounds inhibit PI3Kα activity in human colon adenocarcinoma (HCT-116), breast adenocarcinoma (MCF-7), and breast carcinoma (T47D) cell lines. Results additionally showed that these compounds exhibit selective antiproliferative activity, induce apoptosis, and suppress the VEGF production. Compounds 2b, 2d, and 2g displayed promising inhibitory activity in HCT-116 suggesting that hydrophobic and/or hydrogen bond-acceptor mediate(s) ligand-receptor interaction on o- and m-positions. Furthermore, compounds 2g, 2i, 2j, and 2h, bearing hydrophobic moiety on m- and p-position, exerted high antiproliferative activity in T47D and MCF-7 cells, whereas compound 2e showed selectivity against T47D and MCF-7. Molecular docking studies against PI3Kα and caspase-3 demonstrated a strong correlation between the predicted binding affinity (ΔGobsd) and IC50 values of prepared compounds for the caspase-3 model, implying that the cellulous inhibitory activity was caspase-3-dependent. Moreover, Glide docking against PI3Kα identified Ser774, Lys802, E849, V851, and Asp933 as key binding residues. The series exerted a potential PI3Kα inhibitory activity in human carcinoma cell lines expressing PI3Kα. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Development of On-Line High Performance Liquid Chromatography (HPLC)-Biochemical Detection Methods as Tools in the Identification of Bioactives

PubMed Central

Malherbe, Christiaan J.; de Beer, Dalene; Joubert, Elizabeth

2012-01-01

Biochemical detection (BCD) methods are commonly used to screen plant extracts for specific biological activities in batch assays. Traditionally, bioactives in the most active extracts were identified through time-consuming bio-assay guided fractionation until single active compounds could be isolated. Not only are isolation procedures often tedious, but they could also lead to artifact formation. On-line coupling of BCD assays to high performance liquid chromatography (HPLC) is gaining ground as a high resolution screening technique to overcome problems associated with pre-isolation by measuring the effects of compounds post-column directly after separation. To date, several on-line HPLC-BCD assays, applied to whole plant extracts and mixtures, have been published. In this review the focus will fall on enzyme-based, receptor-based and antioxidant assays. PMID:22489144

Active-learning strategies in computer-assisted drug discovery.

PubMed

Reker, Daniel; Schneider, Gisbert

2015-04-01

High-throughput compound screening is time and resource consuming, and considerable effort is invested into screening compound libraries, profiling, and selecting the most promising candidates for further testing. Active-learning methods assist the selection process by focusing on areas of chemical space that have the greatest chance of success while considering structural novelty. The core feature of these algorithms is their ability to adapt the structure-activity landscapes through feedback. Instead of full-deck screening, only focused subsets of compounds are tested, and the experimental readout is used to refine molecule selection for subsequent screening cycles. Once implemented, these techniques have the potential to reduce costs and save precious materials. Here, we provide a comprehensive overview of the various computational active-learning approaches and outline their potential for drug discovery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthesis and Evaluation of In Vitro Antibacterial and Antitumor Activities of Novel N,N-Disubstituted Schiff Bases

PubMed Central

Luo, Heng; Xia, Yu-fen; Sun, Bao-fei; Huang, Li-rong; Wang, Xing-hui; Lou, Hua-yong; Zhu, Xu-hui

2017-01-01

To get inside the properties of N,N-disubstituted Schiff bases, we synthesized three high-yielding benzaldehyde Schiff bases. We used the reaction between salicylaldehyde and different diamine compounds, including diamine, ethanediamine, and o-phenylenediamine, determining the structure of obtained molecules by nuclear magnetic resonance spectroscopy and electrospray ionization mass spectroscopy. We thus evaluated the microbicidal and antitumor activity of these compounds, showing that salicylaldehyde-hydrazine hydrate Schiff base (compound 1a) significantly inhibited the growth of S. aureus; salicylaldehyde-o-phenylenediamine Schiff base (compound 1c) displayed a strong capability to inhibit the proliferation of leukemia cell lines K562 and HEL. Moreover, we observed that the antibacterial action of 1a might be associated with the regulation of the expression of key virulence genes in S. aureus. Compound 1c resulted in a strong apoptotic activity against leukemia cells, also affecting the cell cycle distribution. Overall, our novel N,N-disubstituted Schiff bases possess unique antibacterial or antitumor activities that exhibit the potent application prospect in prophylactic or therapeutic interventions, providing new insights for developing new antibacterial and anticancer chemical agents. PMID:28713593

Characterization and structure elucidation of antibacterial compound of Streptomyces sp. ECR77 isolated from east coast of India.

PubMed

Thirumurugan, D; Vijayakumar, R

2015-05-01

Forty marine actinobacteria were isolated from the sediments of east coast (Bay of Bengal) region of Tamilnadu, India. Morphologically distinct colonies were primarily tested against fish pathogenic bacteria such as Vibrio cholerae, V. parahaemolyticus, V. alginolyticus, Pseudomonas fluorescens and Aeromonas hydrophila by cross-streak plate method. The secondary metabolites produced by the highly potential strain cultured on starch casein broth were extracted separately with various solvents such as alcohol, ethyl acetate, methanol, petroleum ether and chloroform. The antibacterial assay of the bioactive compounds was tested against the fish pathogenic bacteria by well diffusion method. Of the various solvents used, the ethyl acetate extract of the isolate had good antibacterial activity. The potential strain was identified as Streptomyces labedae by phenotypic, 16S rRNA gene sequence and phylogenetic analysis. Purification of the biologically active compounds by column chromatography led to isolation of 27 fractions. The biologically active fraction was re-chromatographed on a silica gel column to obtain a single active compound, namely N-isopentyltridecanamide. The structure of the compounds was elucidated on the basis of ultra violet, Fourier transform infrared and nuclear magnetic resonance spectra.

Process for preparing active oxide powders

DOEpatents

Berard, Michael F.; Hunter, Jr., Orville; Shiers, Loren E.; Dole, Stephen L.; Scheidecker, Ralph W.

1979-02-20

An improved process for preparing active oxide powders in which cation hydroxide gels, prepared in the conventional manner are chemically dried by alternately washing the gels with a liquid organic compound having polar characteristics and a liquid organic compound having nonpolar characteristics until the mechanical water is removed from the gel. The water-free cation hydroxide is then contacted with a final liquid organic wash to remove the previous organic wash and speed drying. The dried hydroxide treated in the conventional manner will form a highly sinterable active oxide powder.

Secondary Metabolites from Marine Microorganisms. II. Marine Fungi and Their Habitats.

PubMed

Orlova, T I; Bulgakova, V G; Polin, A N

Marine-derived fungi are of great interest as a new promising source of biologically active products such as anticancer compounds, antibiotics, inhibitors of biochemical processes. Since marine organisms inhabit biologically competitive environment with unique conditions, the chemical diversity of the secondary metabolites from marine fungi is considerably high. Recent genomic studies demonstrated that fungi can carry gene clasters encoding production of previously unknown secondary metabolites. Activation of the attenuated or silent genes would be useful either for improving activities of the known compounds or for discovery of new products.

[Progresses in screening active compounds from herbal medicine by affinity chromatography].

PubMed

Feng, Ying-shu; Tong, Shan-shan; Xu, Xi-ming; Yu, Jiang-nan

2015-03-01

Affinity chromatography is a chromatographic method for separating molecules using the binding characteristics of the stationary phase with potential drug molecules. This method can be performed as a high throughput screening method and a chromatographic separation method to screen a variety of active drugs. This paper summarizes the history of affinity chromatography, screening technology of affinity chromatography, and application of affinity chromatography in screening bio-active compounds in herbal medicines, and then discusses its application prospects, in order to broaden applications of the affinity chromatography in drug screening.

Antimicrobial and antioxidant activities of triterpenoid and phenolic derivatives from two Cameroonian Melastomataceae plants: Dissotis senegambiensis and Amphiblemma monticola.

PubMed

Nzogong, Raissa Tioyem; Ndjateu, Fabrice Sterling Tchantchou; Ekom, Steve Endeguele; Fosso, Jules-Arnaud Mboutchom; Awouafack, Maurice Ducret; Tene, Mathieu; Tane, Pierre; Morita, Hiroyuki; Choudhary, Muhammad Iqbal; Tamokou, Jean-de-Dieu

2018-05-16

Antimicrobial resistance is a serious threat against humankind and the search for new therapeutics is needed. This study aims to investigate the antimicrobial and antioxidant activities of ethanol extracts and compounds isolated from Dissotis senegambiensis and Amphiblemma monticola, two Cameroonian Melastomataceae species traditionally used for the treatment of fever, malaria and infectious diseases. The plant extracts were prepared by maceration in ethanol. Standard chromatographic and spectroscopic methods were used to isolate and identify fourteen compounds from the two plant species [1-6 (from D. senegambiensis), 3, 4 and 7-14 (from A. monticola)]. A two-fold serial micro-dilution method was used to determine the minimum inhibitory concentration (MIC) against four bacterial strains including two resistant bacterial strains, methicillin resistant S. aureus (MRSA3) and methicillin resistant S. aureus (MRSA4) and three yeast strains. The fractionation of EtOH extracts afforded fourteen compounds belonging to triterpenoid and phenolic derivatives. The ethanol extracts, compounds 3, 5-8, 10 and the mixture of 10 + 12 were active against all the tested bacterial and fungal species. Compound 7 (MIC = 16-32 μg/mL) and 10 (MIC = 8-16 μg/mL) displayed the largest antibacterial and antifungal activities, respectively. Compounds 7, 10 and the mixture of 10 + 12 showed prominent antibacterial activity against methicillin- resistant S. aureus (MRSA) which is in some cases equal to that of ciprofloxacin used as reference antibacterial drug. Compound 8 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and butylated hydroxytoluene used as reference antioxidants. The tested samples were non-toxic to normal cells highlighting their good selectivity. The result of this investigation reveals the potential of D. senegambiensis and A. monticola as well as the most active compounds in the search for new antimicrobial and antioxidant agents. So, further investigations are needed.

New quinoline derivatives demonstrate a promising antimalarial activity against Plasmodium falciparum in vitro and Plasmodium berghei in vivo.

PubMed

Soares, Roberta Reis; da Silva, José Marcio Fernandes; Carlos, Bianca Cecheto; da Fonseca, Camila Campos; de Souza, Laila Salomé Araújo; Lopes, Fernanda Valério; de Paula Dias, Rafael Mafra; Moreira, Paulo Otávio Lourenço; Abramo, Clarice; Viana, Gustavo Henrique Ribeiro; de Pila Varotti, Fernando; da Silva, Adilson David; Scopel, Kézia Katiani Gorza

2015-06-01

Malaria continues to be an important public health problem in the world. Nowadays, the widespread parasite resistance to many drugs used in antimalarial therapy has made the effective treatment of cases and control of the disease a constant challenge. Therefore, the discovery of new molecules with good antimalarial activity and tolerance to human use can be really important in the further treatment of the disease. In this study we have investigated the antiplasmodial activity of 10 synthetic compounds derived from quinoline, five of them combined to sulfonamide and five to the hydrazine or hydrazide group. The compounds were evaluated according to their cytotoxicity against HepG2 and HeLa cell lines, their antimalarial activity against CQ-sensitive and CQ-resistant Plasmodium falciparum strains and, finally, their schizonticide blood action in mice infected with Plasmodium berghei NK65. The compounds exhibited no cytotoxic action in HepG2 and HeLa cell lines when tested up to a concentration of 100 μg/mL. In addition, the hydrazine or hydrazide derivative compounds were less cytotoxic against cell lines and more active against CQ-sensitive and CQ-resistant P. falciparum strains, showing high SI (>1000 when SI was calculated using the CC50 from the 3D7 strain as reference). When tested in vivo, the hydrazine derivative 1f compound showed activity against the development of blood parasites similar to that observed with CQ, the reference drug. Interestingly, the 1f compound demonstrated the best LipE value (4.84) among all those tested in vivo. Considering the in vitro and in vivo activities of the compounds studied here and the LipE values, we believe the 1f compound to be the most promising molecule for further studies in antimalarial chemotherapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Constituents of PG201 (Layla(®)), a multi-component phytopharmaceutical, with inhibitory activity on LPS-induced nitric oxide and prostaglandin E2 productions in macrophages.

PubMed

Kim, Hyun Ji; Kim, Hye Mi; Ryu, Byeol; Lee, Woo-Seok; Shin, Ji-Sun; Lee, Kyung-Tae; Jang, Dae Sik

2016-02-01

Fourteen compounds, coumarin (1), demethylsuberosin (2), xanthotoxin (3), psoralen (4), decursinol (5), decursin (6), decursinol angelate (7), chikusetsusaponin IVa (8), chikusetsusaponin IVa methyl ester (9), ethyl caffeate (10), syringaresinol (11), cnidilide (12), farnesol (13), and linoleic acid (14), were isolated from phytopharmaceutical PG201 (Layla(®)) by activity-guided fractionation utilizing inhibitory activity on nitric oxide (NO) production in vitro. The isolates 1-14 were evaluated for their inhibitory activity on LPS-induced NO and prostaglandin E2 (PGE2) productions in RAW 264.7 cells. All the compounds except 14 displayed suppressive effects on LPS-induced NO and PGE2 production with IC50 values ranging from 8 to 60 μM. Among these, compound 10 showed the most potent inhibitory effect on NO production from RAW 264.7 cells with an IC50 value of 8.25 μM. Compounds 2, 9, and 10 exhibited high inhibitory effects on PGE2 production with the IC50 values of 9.42, 7.51, and 6.49 μM, respectively. These findings suggest that compounds 2, 9, and 10 are the potential anti-inflammatory active constituents of PG201 and further study may be needed to explain their mechanism of action.

Suspensions as a Valuable Alternative to Extemporaneously Compounded Capsules.

PubMed

Dijkers, Eli; Nanhekhan, Valerie; Thorissen, Astrid; Polonini, Hudson

2017-01-01

The objective of this study was to determine the variation in content of 74 different active pharmaceutical ingredients (APIs) and compare it with what is known in the literature for the content uniformity of extemporaneous prepared capsules. Active pharmaceutical ingredients quantification was performed by high-performance liquid chromatography, via a stability-indicating method. Samples for all active pharmaceutical ingredients were taken throughout a 90-day period and the content was determined. In total, 5,190 different samples were analyzed for 74 different active pharmaceutical ingredients at room (15°C to 25°C) or controlled refrigerated temperature (2°C to 8°C). Each of these datasets was analyzed according to the United States Pharmacopeia Content Uniformity monograph, corrected for the sample number. The mean acceptance values were well within specifications. In addition, all suspensions complied with the criteria defined by the British Pharmacopoeia monograph for Content Uniformity of Liquid Dispersions for both room and controlled refrigerated temperature. In previous studies, it was found that a routine weight variation check is often not sufficient for quality assurance of extemporaneous prepared capsules. Compounded oral liquids show little variation in content for 74 different active pharmaceutical ingredients; therefore, compounded oral liquids are a suitable alternative when compounding individualized medications for patients. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

QSAR-driven design, synthesis and discovery of potent chalcone derivatives with antitubercular activity.

PubMed

Gomes, Marcelo N; Braga, Rodolpho C; Grzelak, Edyta M; Neves, Bruno J; Muratov, Eugene; Ma, Rui; Klein, Larry L; Cho, Sanghyun; Oliveira, Guilherme R; Franzblau, Scott G; Andrade, Carolina Horta

2017-09-08

New anti-tuberculosis (anti-TB) drugs are urgently needed to battle drug-resistant Mycobacterium tuberculosis strains and to shorten the current 6-12-month treatment regimen. In this work, we have continued the efforts to develop chalcone-based anti-TB compounds by using an in silico design and QSAR-driven approach. Initially, we developed SAR rules and binary QSAR models using literature data for targeted design of new heteroaryl chalcone compounds with anti-TB activity. Using these models, we prioritized 33 compounds for synthesis and biological evaluation. As a result, 10 heteroaryl chalcone compounds (4, 8, 9, 11, 13, 17-20, and 23) were found to exhibit nanomolar activity against replicating mycobacteria, low micromolar activity against nonreplicating bacteria, and nanomolar and micromolar against rifampin (RMP) and isoniazid (INH) monoresistant strains (rRMP and rINH) (<1 μM and <10 μM, respectively). The series also show low activity against commensal bacteria and generally show good selectivity toward M. tuberculosis, with very low cytotoxicity against Vero cells (SI = 11-545). Our results suggest that our designed heteroaryl chalcone compounds, due to their high potency and selectivity, are promising anti-TB agents. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Antioxidant and antimicrobial effects of phenolic compounds extracts of Northeast Portugal honey.

PubMed

Estevinho, Letícia; Pereira, Ana Paula; Moreira, Leandro; Dias, Luís G; Pereira, Ermelinda

2008-12-01

Phenolic compounds of dark and clear honeys from Trás-os-Montes of Portugal were extracted with Amberlite XAD-2 and evaluated for their antioxidant and antimicrobial activities. The antioxidant effect was studied using the in vitro test capacity of scavenge the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical and of reducing power of iron (III)/ferricyanide complex. The antimicrobial activity was screened using three Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus, Staphylococcus lentus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli). The results obtained from the partial identification of honey phenolic compounds by high-performance liquid chromatography with a diode array detector showed that p-hydroxibenzoic acid, cinnamic acid, naringenin, pinocembrin and chrysin are the phenolic compounds present in most of the samples analyzed. Antioxidant potential was dependent of honey extract concentration and the results showed that dark honey phenolic compounds had higher activity than the obtained from clear honey. In the biological assays, results showed that S. aureus were the most sensitive microrganisms and B. subtilis, S. lentus, K. pneumoniae and E. coli were each moderately sensitive to the antimicrobial activity of honey extracts. Nevertheless, no antimicrobial activity was observed in the test with P. aeruginosa.

COMPUTER PREDICTION OF BIOLOGICAL ACTIVITY OF DIMETHYL-N-(BENZOYL)AMIDOPHOSPHATE AND DIMETHYL-N-(PHENYLSULFONYL)AMIDOPHOSPHATE, EVALUATION OF THEIR CYTOTOXIC ACTIVITY AGAINST LEUKEMIC CELLS IN VITRO.

PubMed

Grynyuk, I I; Prylutska, S V; Kariaka, N S; Sliva, T Yu; Moroz, O V; Franskevych, D V; Amirkhanov, V M; Matyshevska, O P; Slobodyanik, M S

2015-01-01

Structural analogues of β-diketones--dimethyl-N-(benzoyl)amidophosphate (HCP) and dimethyl-N-(phenylsulfonyl)amidophosphate (HSP) were synthesized and identified by the methods of IR, 1H and 31P NMR spectroscopy. Screening of biological activity and calculation of physicochemical parameters of HCP and HSP compounds were done with the use of PASS and ACD/Labs computer programs. A wide range of biological activity of synthesized compounds, antitumor activity in particular, has been found. Calculations of the bioavailability criteria indicate that the investigated compounds have no deviations from Lipinski's rules. HCP compound is characterized by a high lipophilicity at physiological pH as compared to HSP. It was found that cytotoxic effect of the studied compounds on the leukemic L1210 cells was of time- and dose-dependent character. HCP is characterized by more pronounced and early cytotoxic effects as compared to HSP. It was shown that 2.5 mM HCP increased ROS production 3 times in the early period of incubation, and decreased cell viability by 40% after 48 h, and by 66%--after 72 h. Based on the computer calculation and undertaken research, HCP was selected for target chemical modifications and enhancement of its antitumor effect.

Identification of compounds with anti-convulsant properties in a zebrafish model of epileptic seizures

PubMed Central

Baxendale, Sarah; Holdsworth, Celia J.; Meza Santoscoy, Paola L.; Harrison, Michael R. M.; Fox, James; Parkin, Caroline A.; Ingham, Philip W.; Cunliffe, Vincent T.

2012-01-01

SUMMARY The availability of animal models of epileptic seizures provides opportunities to identify novel anticonvulsants for the treatment of people with epilepsy. We found that exposure of 2-day-old zebrafish embryos to the convulsant agent pentylenetetrazole (PTZ) rapidly induces the expression of synaptic-activity-regulated genes in the CNS, and elicited vigorous episodes of calcium (Ca2+) flux in muscle cells as well as intense locomotor activity. We then screened a library of ∼2000 known bioactive small molecules and identified 46 compounds that suppressed PTZ-inducedtranscription of the synaptic-activity-regulated gene fos in 2-day-old (2 dpf) zebrafish embryos. Further analysis of a subset of these compounds, which included compounds with known and newly identified anticonvulsant properties, revealed that they exhibited concentration-dependent inhibition of both locomotor activity and PTZ-induced fos transcription, confirming their anticonvulsant characteristics. We conclude that this in situ hybridisation assay for fos transcription in the zebrafish embryonic CNS is a robust, high-throughput in vivo indicator of the neural response to convulsant treatment and lends itself well to chemical screening applications. Moreover, our results demonstrate that suppression of PTZ-induced fos expression provides a sensitive means of identifying compounds with anticonvulsant activities. PMID:22730455

Antioxidant activity from encapsulated Cinnamaldehyde-Chitosan

NASA Astrophysics Data System (ADS)

Ariestiani, Bonita; Purbowatingrum; Ngadiwiyana; Ismiyarto; Fachriyah, Enny; Nurani, Khikmah

2018-05-01

Cinnamaldehyde compound is a powerful antioxidant agent that can effectively combat the free radicals referred to superoxide anions and hydroxy radicals, as well as other free radicals in in vitro testing. An antioxidant is an electron donor or reductant. antioxidants are also compounds that can inhibit oxidation reactions by binding to free radicals and highly reactive molecules. As a result, cell damage will be inhibited. However, the use of this compound still provides unsatisfactory results due to its degradation during the absorption process. The solution offered to solve the problem is by encapsulated it within chitosan nanoparticles that serve to protect the bioactive compound from degradation, increases of solubility and delivery of a bioactive compound to the target site by using freeze-drying technique. The value of encapsulation efficiency (EE) of cinnamaldyhde which encapsulated within chitosan nanoparticles is about 74,389% also antioxidant activity test showed that cinnamaldehyde encapsulated by nanochitosan could inhibit free radicals of 223.44 in IC50.

Phenolic Compounds Analysis of Root, Stalk, and Leaves of Nettle

PubMed Central

Otles, Semih; Yalcin, Buket

2012-01-01

Types of nettles (Urtica dioica) were collected from different regions to analyze phenolic compounds in this research. Nettles are specially grown in the coastal part. According to this kind of properties, nettle samples were collected from coastal part of (Mediterranean, Aegean, Black sea, and Marmara) Turkey. Phenolic profile, total phenol compounds, and antioxidant activities of nettle samples were analyzed. Nettles were separated to the part of root, stalk, and leaves. Then, these parts of nettle were analyzed to understand the difference of phenolic compounds and amount of them. Nettle (root, stalk and leaves) samples were analyzed by using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) to qualitative and quantitative determination of the phenolic compounds. Total phenolic components were measured by using Folin-Ciocalteu method. The antioxidant activity was measured by using DPPH (2,2-diphenyl-1-picrylhydrazyl) which is generally used for herbal samples and based on single electron transfer (SET). PMID:22593694

Phenolic compounds analysis of root, stalk, and leaves of nettle.

PubMed

Otles, Semih; Yalcin, Buket

2012-01-01

Types of nettles (Urtica dioica) were collected from different regions to analyze phenolic compounds in this research. Nettles are specially grown in the coastal part. According to this kind of properties, nettle samples were collected from coastal part of (Mediterranean, Aegean, Black sea, and Marmara) Turkey. Phenolic profile, total phenol compounds, and antioxidant activities of nettle samples were analyzed. Nettles were separated to the part of root, stalk, and leaves. Then, these parts of nettle were analyzed to understand the difference of phenolic compounds and amount of them. Nettle (root, stalk and leaves) samples were analyzed by using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) to qualitative and quantitative determination of the phenolic compounds. Total phenolic components were measured by using Folin-Ciocalteu method. The antioxidant activity was measured by using DPPH (2,2-diphenyl-1-picrylhydrazyl) which is generally used for herbal samples and based on single electron transfer (SET).

Identification of Rotundone as a Potent Odor-Active Compound of Several Kinds of Fruits.

PubMed

Nakanishi, Akira; Fukushima, Yusuke; Miyazawa, Norio; Yoshikawa, Keisuke; Maeda, Tomoko; Kurobayashi, Yoshiko

2017-06-07

An investigation of the aromas of grapefruit, orange, apple, and mango revealed the presence of an odor-active compound that gave off a strong woody odor when assessed by gas chromatography-olfactometry. We isolated the compound from a high-boiling fraction of an orange essential oil, and subsequent nuclear magnetic resonance analyses of the isolated compound identified it as rotundone. Mass spectra and retention indices obtained from aroma concentrates of grapefruit, apple, and mango were identical to those of rotundone, which was therefore determined to be the common woody compound in these fruits. Sensory analyses were performed to assess the effects of rotundone on model beverages of the various fruits. It was revealed that rotundone added at even subthreshold levels to model beverages did not confer directly the woody odor, but had significant effects on the overall flavors of the beverages, helping them to better approximate the natural flavors of the fruits.

Marinobacter sp. from marine sediments produce highly stable surface-active agents for combatting marine oil spills.

PubMed

Raddadi, Noura; Giacomucci, Lucia; Totaro, Grazia; Fava, Fabio

2017-11-02

The application of chemical dispersants as a response to marine oil spills is raising concerns related to their potential toxicity also towards microbes involved in oil biodegradation. Hence, oil spills occurring under marine environments necessitate the application of biodispersants that are highly active, stable and effective under marine environment context. Biosurfactants from marine bacteria could be good candidates for the development of biodispersant formulations effective in marine environment. This study aimed at establishing a collection of marine bacteria able to produce surface-active compounds and evaluating the activity and stability of the produced compounds under conditions mimicking those found under marine environment context. A total of 43 different isolates were obtained from harbor sediments. Twenty-six of them produced mainly bioemulsifiers when glucose was used as carbon source and 16 were biosurfactant/bioemulsifiers producers after growth in the presence of soybean oil. Sequencing of 16S rRNA gene classified most isolates into the genus Marinobacter. The produced emulsions were shown to be stable up to 30 months monitoring period, in the presence of 300 g/l NaCl, at 4 °C and after high temperature treatment (120 °C for 20 min). The partially purified compounds obtained after growth on soybean oil-based media exhibited low toxicity towards V. fischeri and high capability to disperse crude oil on synthetic marine water. To the best of our knowledge, stability characterization of bioemulsifiers/biosurfactants from the non-pathogenic marine bacterium Marinobacter has not been previously reported. The produced compounds were shown to have potential for different applications including the environmental sector. Indeed, their high stability in the presence of high salt concentration and low temperature, conditions characterizing the marine environment, the capability to disperse crude oil and the low ecotoxicity makes them interesting for the development of biodispersants to be used in combatting marine oil spills.

A Study of a Compound Solar Eruption with Two Consecutive Erupting Magnetic Structures

NASA Astrophysics Data System (ADS)

Dhakal, Suman K.; Chintzoglou, Georgios; Zhang, Jie

2018-06-01

We report a study of a compound solar eruption that was associated with two consecutively erupting magnetic structures and correspondingly two distinct peaks, during impulsive phase, of an M-class flare (M8.5). Simultaneous multi-viewpoint observations from SDO, GOES and STEREO-A show that this compound eruption originated from two pre-existing sigmoidal magnetic structures lying along the same polarity inversion line. Observations of the associated pre-existing filaments further show that these magnetic structures are lying one on top of the other, separated by 12 Mm in height, in a so-called “double-decker” configuration. The high-lying magnetic structure became unstable and erupted first, appearing as an expanding hot channel seen at extreme ultraviolet wavelengths. About 12 minutes later, the low-lying structure also started to erupt and moved at an even faster speed compared to the high-lying one. As a result, the two erupting structures interacted and merged with each other, appearing as a single coronal mass ejection in the outer corona. We find that the double-decker configuration is likely caused by the persistent shearing motion and flux cancellation along the source active region’s strong-gradient polarity inversion line. The successive destabilization of these two separate but closely spaced magnetic structures, possibly in the form of magnetic flux ropes, led to a compound solar eruption. The study of the compound eruption provides a unique opportunity to reveal the formation process, initiation, and evolution of complex eruptive structures in solar active regions.

Fun with Ionic Compounds

ERIC Educational Resources Information Center

Logerwell, Mollianne G.; Sterling, Donna R.

2007-01-01

Ionic bonding is a fundamental topic in high school chemistry, yet it continues to be a concept that students struggle to understand. Even if they understand atomic structure and ion formation, it can be difficult for students to visualize how ions fit together to form compounds. This article describes several engaging activities that help…

The isolation and identification of two compounds with predominant radical scavenging activity in hempseed (seed of Cannabis sativa L.).

PubMed

Chen, Tianpeng; He, Jinfeng; Zhang, Jianchun; Li, Xiaohui; Zhang, Hua; Hao, Jianxiong; Li, Lite

2012-09-15

Forty samples were extracted from defatted kernels and hulls of two varieties of hempseed (Bama and Yunma No. 1) using 10 different polar solvent systems. The radical scavenging capacity of the extracts was evaluated using 2,2-diphenyl-1-pikrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays and the total phenolic content was determined by Folin-Ciocalteu's phenol reagent. The correlation analysis indicated that the antioxidants in hempseed belonged to phenolic and DPPH() assay was suitable for evaluating the radical scavenging activity. Two compounds, with predominant antiradical activity, were isolated in 60% ethanol extract of hempseed hull using macroporous resin absorption, LH-20 gel chromatography, and high performance liquid chromatography methods, which were identified as N-trans-caffeoyltyramine and cannabisin B by high-resolution mass spectra, nuclear magnetic resonance spectra, and ultraviolet data. The two compounds exhibited significant high DPPH() scavenging activity and protective effect against in vitro oxidation of human low-density lipoprotein compared with extracts from flaxseed, grape seed, and soybean. This suggests that hempseed hull extract is a potential source of natural antioxidants, which could be added to dietary supplements to help prevent oxidative stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

Orally active, nonpeptide vasopressin V1 antagonists. A novel series of 1-(1-substituted 4-piperidyl)-3,4-dihdyro-2(1H)-quinolinone.

PubMed

Ogawa, H; Yamamura, Y; Miyamoto, H; Kondo, K; Yamashita, H; Nakaya, K; Chihara, T; Mori, T; Tominaga, M; Yabuuchi, Y

1993-07-09

A series of compounds has been synthesized and demonstrated to be antagonists of V1 receptors both in vitro and in vivo. These compounds are structurally related to the 1-(4-piperidyl)-2(1H)-quinolinones, including OPC-21268, an orally bioavailable AVP V1 antagonist with high V1 specificity. It has been found that the introduction of an acetamide group on the terminal alkoxy chain of 41-44 leads to an increase in oral activity. Certain of these compounds may have efficacy in the study of AVP V1 receptors.

Synthesis and preliminary biological evaluation of potent and selective 2-(3-alkoxy-1-azetidinyl) quinolines as novel PDE10A inhibitors with improved solubility.

PubMed

Rzasa, Robert M; Frohn, Michael J; Andrews, Kristin L; Chmait, Samer; Chen, Ning; Clarine, Jeffrey G; Davis, Carl; Eastwood, Heather A; Horne, Daniel B; Hu, Essa; Jones, Adrie D; Kaller, Matthew R; Kunz, Roxanne K; Miller, Silke; Monenschein, Holger; Nguyen, Thomas; Pickrell, Alexander J; Porter, Amy; Reichelt, Andreas; Zhao, Xiaoning; Treanor, James J S; Allen, Jennifer R

2014-12-01

We report the discovery of a novel series of 2-(3-alkoxy-1-azetidinyl) quinolines as potent and selective PDE10A inhibitors. Structure-activity studies improved the solubility (pH 7.4) and maintained high PDE10A activity compared to initial lead compound 3, with select compounds demonstrating good oral bioavailability. X-ray crystallographic studies revealed two distinct binding modes to the catalytic site of the PDE10A enzyme. An ex vivo receptor occupancy assay in rats demonstrated that this series of compounds covered the target within the striatum.

Maillard reaction products as "natural antibrowning" agents in fruit and vegetable technology.

PubMed

Billaud, Catherine; Maraschin, Christelle; Chow, Yin-Naï; Chériot, Sophie; Peyrat-Maillard, Marie-Nöelle; Nicolas, Jacques

2005-07-01

The effects of Maillard reaction products (MRPs), synthesized from a sugar (pentose, hexose, or disaccharide) and either a cysteine-related compound, an amino acid, or a sulfur compound, were investigated on polyphenoloxidase (PPO) activity from apple, mushroom, and eggplant. The optimal conditions for the production of inhibitory MRPs were performed using two-factor and five-level central experimental designs. It resulted that thiol-derived MRPs were highly prone to give rise to inhibitory compounds of PPO activity. Technological assays were also performed to test the efficiency of selected MRPs in the prevention of enzymatic browning in raw and minimally processed fruits and vegetables.

UHPLC-MS/MS phenolic profiling and in vitro antioxidant activities of Inula graveolens (L.) Desf.

PubMed

Silinsin, Muzaffer; Bursal, Ercan

2018-06-01

Inula graveolens (L.) Desf. is an annual aromatic herb which has various uses on alternative medicine in many region of the world. In this study, antioxidant activities of ethanol and water extracts of the plant leaves were determined by in vitro DPPH method and phenolic composition of the plant sample was determined by LC-MS/MS analysis. The results showed that chlorogenic acid, quinic acid, hyperoside, protocatechuic acid and quercetin were the major phenolic compounds among the 27 standard compounds. The significant antioxidant capacity of the plant might be related with the high abundance of phenolic compounds.

Large-Scale Selection and Breeding To Generate Industrial Yeasts with Superior Aroma Production

PubMed Central

Steensels, Jan; Meersman, Esther; Snoek, Tim; Saels, Veerle

2014-01-01

The concentrations and relative ratios of various aroma compounds produced by fermenting yeast cells are essential for the sensory quality of many fermented foods, including beer, bread, wine, and sake. Since the production of these aroma-active compounds varies highly among different yeast strains, careful selection of variants with optimal aromatic profiles is of crucial importance for a high-quality end product. This study evaluates the production of different aroma-active compounds in 301 different Saccharomyces cerevisiae, Saccharomyces paradoxus, and Saccharomyces pastorianus yeast strains. Our results show that the production of key aroma compounds like isoamyl acetate and ethyl acetate varies by an order of magnitude between natural yeasts, with the concentrations of some compounds showing significant positive correlation, whereas others vary independently. Targeted hybridization of some of the best aroma-producing strains yielded 46 intraspecific hybrids, of which some show a distinct heterosis (hybrid vigor) effect and produce up to 45% more isoamyl acetate than the best parental strains while retaining their overall fermentation performance. Together, our results demonstrate the potential of large-scale outbreeding to obtain superior industrial yeasts that are directly applicable for commercial use. PMID:25192996

Nontoxic combretafuranone analogues with high in vitro antibacterial activity.

PubMed

Horký, P; Voráčová, M; Konečná, K; Sedlák, D; Bartůněk, P; Vacek, J; Kuneš, J; Pour, M

2018-01-01

A library of thirty two 3,4-diphenylfuranones related to both combretastatin A-4 and antifungal 5-(acyloxymethyl)-3-(halophenyl)-2,5-dihydrofuran-2-ones was prepared. Cytotoxic effects on a panel of cancer and normal cell lines and antiinfective activity were evaluated, and the data were complemented with tests for the activation of caspase 3 and 7. High cytotoxicity was observed in some of the halogenated analogues, eg. 3-(3,4-dichlorophenyl)-4-(4-methylphenyl)-2,5-dihydrofuran-2-one with IC 50 0.12-0.23 μM, but the compounds were also highly toxic against non-malignant control cells. More importantly, notable antibacterial activity indicating G + selectivity has been found in the 3,4-diarylfuranone class of compounds for the first time. Hydroxymethylation of furanone C5 knocked out cytotoxic effects (up to 40 μM) while maintaining significant activity against Staphylococcus strains in some derivatives. MIC 95 of the most promising compound, 3-(4-bromophenyl)-5,5-bis(hydroxymethyl)-4-(4-methylphenyl)-2,5-dihydrofuran-2-one against S. aureus strain ATCC 6538 was 0.98 μM (0.38 μg/mL) and 3.9 μM (1.52 μg/mL) after 24 and 48 h, respectively. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Development of a Scintillation Proximity Assay (SPA) Based, High Throughput Screening Feasible Method for the Identification of PDE12 Activity Modulators.

PubMed

Mang, Samuel; Bucher, Hannes; Nickolaus, Peter

2016-01-01

The scintillation proximity assay (SPA) technology has been widely used to establish high throughput screens (HTS) for a range of targets in the pharmaceutical industry. PDE12 (aka. 2'- phosphodiesterase) has been published to participate in the degradation of oligoadenylates that are involved in the establishment of an antiviral state via the activation of ribonuclease L (RNAse-L). Degradation of oligoadenylates by PDE12 terminates these antiviral activities, leading to decreased resistance of cells for a variety of viral pathogens. Therefore inhibitors of PDE12 are discussed as antiviral therapy. Here we describe the use of the yttrium silicate SPA bead technology to assess inhibitory activity of compounds against PDE12 in a homogeneous, robust HTS feasible assay using tritiated adenosine-P-adenylate ([3H]ApA) as substrate. We found that the used [3H]ApA educt, was not able to bind to SPA beads, whereas the product [3H]AMP, as known before, was able to bind to SPA beads. This enables the measurement of PDE12 activity on [3H]ApA as a substrate using a wallac microbeta counter. This method describes a robust and high throughput capable format in terms of specificity, commonly used compound solvents, ease of detection and assay matrices. The method could facilitate the search for PDE12 inhibitors as antiviral compounds.

Design, synthesis and evaluation of some N-methylenebenzenamine derivatives as selective acetylcholinesterase (AChE) inhibitor and antioxidant to enhance learning and memory.

PubMed

Shrivastava, Sushant K; Srivastava, Pavan; Upendra, T V R; Tripathi, Prabhash Nath; Sinha, Saurabh K

2017-02-15

Series of some 3,5-dimethoxy-N-methylenebenzenamine and 4-(methyleneamino)benzoic acid derivatives comprising of N-methylenebenzenamine nucleus were designed, synthesized, characterized, and assessed for their acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory, and antioxidant activity thereby improving learning and memory in rats. The IC 50 values of all the compound along with standard were determined on AChE and BChE enzyme. The free radical scavenging activity was also assessed by in vitro DPPH (2,2-diphenyl-1-picryl-hydrazyl) and hydrogen peroxide radical scavenging assay. The selective inhibitions of all compounds were observed against AChE in comparison with standard donepezil. The enzyme kinetic study of the most active compound 4 indicated uncompetitive AChE inhibition. The docking studies of compound 4 exhibited the worthy interaction on active-site gorge residues Phe330 and Trp279 responsible for its high affinity towards AChE, whereas lacking of the BChE inhibition was observed due to a wider gorge binding site and absence of important aromatic amino acids interactions. The ex vivo study confirmed AChE inhibition abilities of compound 4 at brain site. Further, a considerable decrease in escape latency period of the compound was observed in comparison with standard donepezil through in vivo Spatial Reference Memory (SRM) and Spatial Working Memory (SWM) models which showed the cognition-enhancing potential of compound 4. The in vivo reduced glutathione (GSH) estimation on rat brain tissue homogenate was also performed to evaluate free radical scavenging activity substantiated the antioxidant activity in learning and memory. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of the phenolic content, profile, and antioxidant activity of seeds from nine tree peony (Paeonia section Moutan DC.) species native to China.

PubMed

Zhang, Xiao-Xiao; Shi, Qian-Qian; Ji, Duo; Niu, Li-Xin; Zhang, Yan-Long

2017-07-01

As an important resource of functional food, the seeds of tree peony are rich in phenolic compounds, which are associated with antioxidant activity. However, so far there has not been systematic study on phenolic compositions and antioxidant activity of the seeds from wild tree peony species. The aim of this study was to determine the phenolic content, antioxidant compounds and antioxidant activity of seeds from nine tree peony species native to China. Among the seed samples, Paeonia rockii had the highest total flavonoid content, strongest DPPH and ABTS radical scavenging activities, and strongest cupric reducing capacity; P. decomposita subsp. rotundiloba had the highest total phenolic and flavanol contents, as well as the strongest hydroxyl radical scavenging activity. Sixteen individual phenolic compounds were quantitatively measured, with (+)-catechin being the most abundant component. The content of the phenolic compounds luteolin, paeonol, and the total flavonoid content were significantly correlated with four antioxidant activities. Hierarchical cluster analysis showed that P. rockii and P. decomposita subsp. rotundiloba could be clustered in a group having a high phenolic content and strong antioxidant activity. These results suggest P. rockii and P. decomposita subsp. rotundiloba are the most promising candidates as useful sources of natural antioxidants. Copyright © 2017. Published by Elsevier Ltd.

Novel Podophyllotoxin Derivatives as Partial PPARγ Agonists and their Effects on Insulin Resistance and Type 2 Diabetes.

PubMed

Zhang, Xiangming; Liu, Huijuan; Sun, Bo; Sun, Yan; Zhong, Weilong; Liu, Yanrong; Chen, Shuang; Ling, Honglei; Zhou, Lei; Jing, Xiangyan; Qin, Yuan; Xiao, Ting; Sun, Tao; Zhou, Honggang; Yang, Cheng

2016-11-17

Peroxisome proliferator-activated receptor γ (PPARγ) is recognized as a key regulator of insulin resistance. In this study, we searched for novel PPARγ agonists in a library of structurally diverse organic compounds and determined that podophyllotoxin exhibits partial agonist activity toward PPARγ. Eight novel podophyllotoxin-like derivatives were synthesized and assayed for toxicity and functional activity toward PPARγ to reduce the possible systemic toxic effects of podophyllotoxin and to maintain partial agonist activity toward PPARγ. Cell-based transactivation assays showed that compounds (E)-3-(hydroxy(3,4,5-trimethoxyphenyl)methyl)-4-(4(trifluoromethyl)styryl)dihydrofuran-2(3H)-one (3a) and (E)-4-(3-acetylstyryl)-3-(hydroxyl (3,4,5-trimethoxyphenyl)methyl)dihydrofuran-2(3H)-one (3f) exhibited partial agonist activity. An experiment using human hepatocarcinoma cells (HepG2) that were induced to become an insulin-resistant model showed that compounds 3a and 3f improved insulin sensitivity and glucose consumption. In addition, compounds 3a and 3f significantly improved hyperglycemia and insulin resistance in high-fat diet-fed streptozotocin (HFD-STZ)-induced type 2 diabetic rats at a dose of 15 mg/kg/day administered orally for 45 days, without significant weight gain. Cell toxicity testing also showed that compounds 3a and 3f exhibited weaker toxicity than pioglitazone. These findings suggested that compounds 3a and 3f improved insulin resistance in vivo and in vitro and that the compounds exhibited potential for the treatment of type 2 diabetes mellitus.

Part-1: Design, synthesis and biological evaluation of novel bromo-pyrimidine analogs as tyrosine kinase inhibitors.

PubMed

Munikrishnappa, Chandrashekar Suradhenupura; Puranik, Sangamesh B; Kumar, G V Suresh; Prasad, Y Rajendra

2016-08-25

A novel series of 5-bromo-pyrimidine derivatives (5a-l, 6a-h, 9a-m and 10a-d) were synthesized through multi step reactions starting from 5-bromo-2,4-dichloro pyrimidine. The newly synthesized compounds were characterized using elemental analysis and spectral data (IR, (1)H NMR, (13)C NMR and LC-MS) analysis. The titled compounds were evaluated for their in vitro cytotoxic activity against tumor cell lines panel consisted of HCT116 (human colon cancer cell line), A549 (human lung cancer cell line), K562 (human chronic myeloid leukemia cell line), U937 (human acute monocytic myeloid leukemia cell line), and L02 (human normal cell line) by using MTT assay Mosmann's method. As most of the compounds are highly potent against K562 cells, all the synthesized compounds were evaluated for Bcr/Abl tyrosine kinase inhibitory activity by using well-established ADP-Glo assay method. Dasatinib was utilized as positive control to validate in both biological evaluations. The biological activity revealed that the compounds 5c, 5e, 6g, 9e, 9f and 10c were potent Bcr/Abl kinase inhibitors among the titled compounds. Thus these compounds may be promising lead compounds to be developed as an alternative for current Dasatinib therapy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Predicting novel substrates for enzymes with minimal experimental effort with active learning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pertusi, Dante A.; Moura, Matthew E.; Jeffryes, James G.

Enzymatic substrate promiscuity is more ubiquitous than previously thought, with significant consequences for understanding metabolism and its application to biocatalysis. This realization has given rise to the need for efficient characterization of enzyme promiscuity. Enzyme promiscuity is currently characterized with a limited number of human-selected compounds that may not be representative of the enzyme's versatility. While testing large numbers of compounds may be impractical, computational approaches can exploit existing data to determine the most informative substrates to test next, thereby more thoroughly exploring an enzyme's versatility. To demonstrate this, we used existing studies and tested compounds for four different enzymes,more » developed support vector machine (SVM) models using these datasets, and selected additional compounds for experiments using an active learning approach. SVMs trained on a chemically diverse set of compounds were discovered to achieve maximum accuracies of similar to 80% using similar to 33% fewer compounds than datasets based on all compounds tested in existing studies. Active learning-selected compounds for testing resolved apparent conflicts in the existing training data, while adding diversity to the dataset. The application of these algorithms to wide arrays of metabolic enzymes would result in a library of SVMs that can predict high-probability promiscuous enzymatic reactions and could prove a valuable resource for the design of novel metabolic pathways.« less

Predicting novel substrates for enzymes with minimal experimental effort with active learning.

PubMed

Pertusi, Dante A; Moura, Matthew E; Jeffryes, James G; Prabhu, Siddhant; Walters Biggs, Bradley; Tyo, Keith E J

2017-11-01

Enzymatic substrate promiscuity is more ubiquitous than previously thought, with significant consequences for understanding metabolism and its application to biocatalysis. This realization has given rise to the need for efficient characterization of enzyme promiscuity. Enzyme promiscuity is currently characterized with a limited number of human-selected compounds that may not be representative of the enzyme's versatility. While testing large numbers of compounds may be impractical, computational approaches can exploit existing data to determine the most informative substrates to test next, thereby more thoroughly exploring an enzyme's versatility. To demonstrate this, we used existing studies and tested compounds for four different enzymes, developed support vector machine (SVM) models using these datasets, and selected additional compounds for experiments using an active learning approach. SVMs trained on a chemically diverse set of compounds were discovered to achieve maximum accuracies of ~80% using ~33% fewer compounds than datasets based on all compounds tested in existing studies. Active learning-selected compounds for testing resolved apparent conflicts in the existing training data, while adding diversity to the dataset. The application of these algorithms to wide arrays of metabolic enzymes would result in a library of SVMs that can predict high-probability promiscuous enzymatic reactions and could prove a valuable resource for the design of novel metabolic pathways. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Preclinical Evaluation of the Supercritical Extract of Azadirachta Indica (Neem) Leaves In Vitro and In Vivo on Inhibition of Prostate Cancer Tumor Growth

PubMed Central

Wu, Qiang; Kohli, Manish; Bergen, H. Robert; Cheville, John C.; Karnes, R. Jeffrey; Cao, Hong; Young, Charles Y.F.; Tindall, Donald J.; McNiven, Mark A.; Donkena, Krishna Vanaja

2015-01-01

Azadirachta indica, commonly known as neem, has gained worldwide prominence because of its medical properties, namely antitumor, antiviral, anti-inflammatory, antihyperglycemic, antifungal, and antibacterial activities. Despite these promising results, gaps remain in our understanding of the molecular mechanism of action of neem compounds and their potential for use in clinical trials. We investigated supercritical extract of neem leaves (SENL) for the following: molecular targets in vitro, in vivo efficacy to inhibit tumor growth, and bioactive compounds that exert antitumor activity. Treatment of LNCaP-luc2 prostate cancer cells with SENL suppressed dihydrotestosterone-induced androgen receptor and prostate-specific antigen levels. SENL inhibited integrin β1, calreticulin, and focal adhesion kinase activation in LNCaP-luc2 and PC3 prostate cancer cells. Oral administration of SENL significantly reduced LNCaP-luc2 xenograft tumor growth in mice with the formation of hyalinized fibrous tumor tissue, reduction in the prostate-specific antigen, and increase in AKR1C2 levels. To identify the active anticancer compounds, we fractionated SENL by high-pressure liquid chromatography and evaluated 16 peaks for cytotoxic activity. Four of the 16 peaks exhibited significant cytotoxic activity against prostate cancer cells. Mass spectrometry of the isolated peaks suggested the compounds with cytotoxic activity were nimbandiol, nimbolide, 2′,3′-dihydronimbolide, and 28-deoxonim-bolide. Analysis of tumor tissue and plasma samples from mice treated with SENL indicated 28-deoxonim-bolide and nimbolide as the bioactive compounds. Overall, our data revealed the bioactive compounds in SENL and suggested that the anticancer activity could be mediated through alteration in androgen receptor and calreticulin levels in prostate cancer. PMID:24674886

Antioxidative Activities and Active Compounds of Extracts from Catalpa Plant Leaves

PubMed Central

Xu, Hongyu; Hu, Gege; Dong, Juane; Wei, Qin; Shao, Hongbo; Lei, Ming

2014-01-01

In order to screen the Catalpa plant with high antioxidant activity and confirm the corresponding active fractions from Catalpa ovata G. Don, C. fargesii Bur., and C. bungei C. A. Mey., total flavonoid contents and antioxidant activities of the extracts/fractions of Catalpa plant leaves were determined. The determined total flavonoid content and antioxidant activity were used as assessment criteria. Those compounds with antioxidant activity were isolated with silica gel column chromatography and ODS column chromatography. Our results showed that the total flavonoid content in C. bungei C. A. Mey. (30.07 mg/g·DW) was the highest, followed by those in C. fargesii Bur. (25.55 mg/g·DW) and C. ovata G. Don (24.96 mg/g·DW). According to the determination results of total flavonoid content and antioxidant activity in 3 clones of leaves of C. bungei C. A. Mey., the total flavonoid content and antioxidant activity in crude extracts from C. bungei C. A. Mey. 6 (CA6) leaves were the highest. Moreover, the results showed that the total flavonoid content and antioxidant activities of ethyl acetate (EA) fraction in ethanol crude extracts in CA6 leaves were the highest, followed by n-butanol, petroleum ether (PE), and water fractions. Two flavonoid compounds with antioxidant activity were firstly isolated based on EA fraction. The two compounds were luteolin (1) and apigenin (2), respectively. PMID:25431795

The alteration of components in the fermented Hwangryunhaedok-tang and its neuroprotective activity

PubMed Central

Yang, Hye Jin; Weon, Jin Bae; Lee, Bohyoung; Ma, Choong Je

2011-01-01

Background: Hwangryunhaedok-tang is a traditional herbal prescription that has sedative activity, hypotensive and anti-bacterial effects. Objective: In this study, we investigated the alteration of contents of components in Hwangryunhaedok-tang, antioxidant activity and neuroprotective activity by fermentation with Lactobacillus acidophilus KFRI 128. Materials and Methods: Contents of three marker compounds (geniposide, berberine and palmatine) and unknown compounds in the Hwangryunhaedok-tang (HR) and the fermented Hwangryunhaedok-tang (FHR) were measured and compared using the established high-performance liqued chromatograph coupled with a photodiode (HPLC-DAD) method. The antioxidant activity of HR and FHR were determined by DPPH free radical and hydrogen peroxide (H2O2) scavenging assay. Also, the neuroprotective activities of HR and FHR against glutamate-induced oxidative stress in a mouse hippocampal cell line (HT22) were evaluated by MTT assay. Results: The contents of geniposide and palmatine were decreased but the content of berberine was increased in the FHR. And the contents of unknown compounds (1), (2), (3), (4) and (5) in the HR were altered by fermentation. Electron donating activity (EDA, %) value of FHR was higher than HR for DPPH radical scavenging activity and H2O2 scavenging activity, respectively. In the MTT assay, FHR showed more potent neuroprotective activity than HR by 513.90%. Conclusion: The FHR using microorganism could convert compounds in HR and enhance the antioxidant and neuroprotective activity. PMID:21969791

Antioxidative activities and active compounds of extracts from Catalpa plant leaves.

PubMed

Xu, Hongyu; Hu, Gege; Dong, Juane; Wei, Qin; Shao, Hongbo; Lei, Ming

2014-01-01

In order to screen the Catalpa plant with high antioxidant activity and confirm the corresponding active fractions from Catalpa ovata G. Don, C. fargesii Bur., and C. bungei C. A. Mey., total flavonoid contents and antioxidant activities of the extracts/fractions of Catalpa plant leaves were determined. The determined total flavonoid content and antioxidant activity were used as assessment criteria. Those compounds with antioxidant activity were isolated with silica gel column chromatography and ODS column chromatography. Our results showed that the total flavonoid content in C. bungei C. A. Mey. (30.07 mg/g · DW) was the highest, followed by those in C. fargesii Bur. (25.55 mg/g · DW) and C. ovata G. Don (24.96 mg/g · DW). According to the determination results of total flavonoid content and antioxidant activity in 3 clones of leaves of C. bungei C. A. Mey., the total flavonoid content and antioxidant activity in crude extracts from C. bungei C. A. Mey. 6 (CA6) leaves were the highest. Moreover, the results showed that the total flavonoid content and antioxidant activities of ethyl acetate (EA) fraction in ethanol crude extracts in CA6 leaves were the highest, followed by n-butanol, petroleum ether (PE), and water fractions. Two flavonoid compounds with antioxidant activity were firstly isolated based on EA fraction. The two compounds were luteolin (1) and apigenin (2), respectively.

High-throughput identification of promiscuous inhibitors from screening libraries with the use of a thiol-containing fluorescent probe.

PubMed

McCallum, Megan M; Nandhikonda, Premchendar; Temmer, Jonathan J; Eyermann, Charles; Simeonov, Anton; Jadhav, Ajit; Yasgar, Adam; Maloney, David; Arnold, Alexander Leggy

2013-07-01

Testing small molecules for their ability to modify cysteine residues of proteins in the early stages of drug discovery is expected to accelerate our ability to develop more selective drugs with lesser side effects. In addition, this approach also enables the rapid evaluation of the mode of binding of new drug candidates with respect to thiol reactivity and metabolism by glutathione. Herein, we describe the development of a fluorescence-based high-throughput assay that allows the identification of thiol-reactive compounds. A thiol-containing fluorescent probe, MSTI, was synthesized and used to evaluate small molecules from the Library of Pharmacologically Active Compounds (LOPAC) collection of bioactive molecules. LOPAC compounds that are known to react with sulfur nucleophiles were identified with this assay, for example, irreversible protease inhibitors, nitric oxide-releasing compounds, and proton-pump inhibitors. The results confirm that both electrophilic and redox reactive compounds can be quickly identified in a high-throughput manner, enabling the assessment of screening libraries with respect to thiol-reactive compounds.

An on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-total antioxidant capacity detection system applying two antioxidant methods for activity evaluation of the edible flowers from Prunus mume.

PubMed

Zhang, Xiaoxia; Lin, Zongtao; Fang, Jinggui; Liu, Meixian; Niu, Yanyan; Chen, Shizhong; Wang, Hong

2015-10-02

An on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-total antioxidant capacity detection (HPLC-DAD-ESI-IT-TOF-MS-TACD) system was created for identification and evaluation of antioxidants in Prunus (P.) mume flowers. Applying this system, the HPLC fingerprint, ultraviolet (UV) spectra, mass fragmentations, active profiles against 1,1-diphenylpicryl-2-hydrazyl radical (DPPH•) scavenging activity and ferric reducing antioxidant power (FRAP) of each complex sample were obtained simultaneously after one injection. Synchronous structure identification and activities screening of complex samples were thus accomplished. In this study, 78 compounds were identified from P. mume flowers by their chromatographic behaviors, UV spectra and MS data with the assistance of standard compounds and literature reports. The DPPH and FRAP activity of 24 samples (23 different P. mume varieties and 1 related herbal medicine) were then quantified by their detailed activity profiles from the on-line system, and by the total activity of each sample extract from off-line 96-well plate method. As a result, 21 and 32 compounds in the on-line system showed anti-oxidative effects against DPPH and FRAP, respectively. The established on-line system is efficient, sensitive and reliable to tell the DPPH and FRAP antioxidant activities of individual compound in complex samples, and therefore would be a useful and promising technique for antioxidant screening from different food and medicinal matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemistry and biology of ω-3 PUFA peroxidation-derived compounds.

PubMed

Wang, Weicang; Yang, Haixia; Johnson, David; Gensler, Catherine; Decker, Eric; Zhang, Guodong

2017-09-01

The ω-3 polyunsaturated fatty acids (PUFAs) are among the most popular dietary supplements in the US, but they are chemically unstable and highly prone to lipid peroxidation. Many studies performed in different countries demonstrate that the majority of ω-3 PUFA products on the market are oxidized, suggesting that the resulting ω-3 PUFA peroxidation-derived compounds could be widely consumed by the general public. Therefore, it is of practical importance to understand the effects of these oxidized lipid compounds on human health. In this review, we summarize and discuss the chemical structures and biological activities of ω-3 PUFA peroxidation-derived compounds, and emphasize the importance to better understand the role of lipid peroxidation in biological activities of ω-3 PUFAs. Copyright © 2016 Elsevier Inc. All rights reserved.

Spectral Response and Diagnostics of Biological Activity of Hydroxyl-Containing Aromatic Compounds

NASA Astrophysics Data System (ADS)

Tolstorozhev, G. B.; Mayer, G. V.; Bel'kov, M. V.; Shadyro, O. I.

2016-08-01

Using IR Fourier spectra and employing quantum-chemical calculations of electronic structure, spectra, and proton-acceptor properties, synthetic derivatives of aminophenol exhibiting biological activity in the suppression of herpes, influenza, and HIV viruses have been investigated from a new perspective, with the aim of establishing the spectral response of biological activity of the molecules. It has been experimentally established that the participation of the aminophenol hydroxyl group in intramolecular hydrogen bonds is characteristic of structures with antiviral properties. A quantum-chemical calculation of the proton-acceptor ability of the investigated aminophenol derivatives has shown that biologically active structures are characterized by a high proton-acceptor ability of oxygen of the hydroxyl group. A correlation that has been obtained among the formation of an intramolecular hydrogen bond, high proton-acceptor ability, and antiviral activity of substituted aminophenols enables us to predict the pharmacological properties of new medical preparations of the given class of compounds.

Effect of concentration temperature on some bioactive compounds and antioxidant proprieties of date syrup.

PubMed

Abbès, Fatma; Besbes, Souhail; Brahim, Bchir; Kchaou, Wissal; Attia, Hamadi; Blecker, Christophe

2013-08-01

The effect of the concentration temperature on the antioxidant activity, carotenoid and phenolic compounds of date syrup was investigated. Date juice was concentrated at 100  and at "60  in vacuum". After concentration, total phenolic, tannin, non-tannin, flavonoid and carotenoid content were determined spectrophotometrically and high-performance liquid chromatography was used for determination of 5-Hydroxymethyl-2-furfuraldehyde content. The antioxidant activity of date syrup was evaluated by various antioxidant methods including total antioxidant, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging test, ferric reducing antioxidant power and β-carotene bleaching. All date syrups showed strong antioxidant activity accompanied by high total phenolic contents. Results showed that concentration at 100  significantly enhanced the antioxidant activities and total phenolic contents of date syrups compared to vacuum concentration at 60 . A good correlation between the antioxidant activity and total phenolic content and flavonoid was observed.

Analysis of phenolic compounds in different parts of pomegranate (Punica granatum) fruit by HPLC-PDA-ESI/MS and evaluation of their antioxidant activity: application to different Italian varieties.

PubMed

Russo, Marina; Fanali, Chiara; Tripodo, Giusy; Dugo, Paola; Muleo, Rosario; Dugo, Laura; De Gara, Laura; Mondello, Luigi

2018-06-01

The analysis of pomegranate phenolic compounds belonging to different classes in different fruit parts was performed by high-performance liquid chromatography coupled with photodiode array and mass spectrometry detection. Two different separation methods were optimized for the analysis of anthocyanins and hydrolyzable tannins along with phenolic acids and flavonoids. Two C 18 columns, core-shell and fully porous particle stationary phases, were used. The parameters for separation of phenolic compounds were optimized considering chromatographic resolution and analysis time. Thirty-five phenolic compounds were found, and 28 of them were tentatively identified as belonging to four different phenolic compound classes; namely, anthocyanins, phenolic acids, hydrolyzable tannins, and flavonoids. Quantitative analysis was performed with a mixture of nine phenolic compounds belonging to phenolic compound classes representative of pomegranate. The method was then fully validated in terms of retention time precision, expressed as the relative standard deviation, limit of detection, limit of quantification, and linearity range. Phenolic compounds were analyzed directly in pomegranate juice, and after solvent extraction with a mixture of water and methanol with a small percentage of acid in peel and pulp samples. The accuracy of the extraction method was also assessed, and satisfactory values were obtained. Finally, the method was used to study identified analytes in pomegranate juice, peel, and pulp of six different Italian varieties and one international variety. Differences in phenolic compound profiles among the different pomegranate parts were observed. Pomegranate peel samples showed a high concentration of phenolic compounds, ellagitannins being the most abundant ones, with respect to pulp and juice samples for each variety. With the same samples, total phenols and antioxidant activity were evaluated through colorimetric assays, and the results were correlated among them.

Inhibition of dengue virus replication by a class of small-molecule compounds that antagonize dopamine receptor d4 and downstream mitogen-activated protein kinase signaling.

PubMed

Smith, Jessica L; Stein, David A; Shum, David; Fischer, Matthew A; Radu, Constantin; Bhinder, Bhavneet; Djaballah, Hakim; Nelson, Jay A; Früh, Klaus; Hirsch, Alec J

2014-05-01

Dengue viruses (DENV) are endemic pathogens of tropical and subtropical regions that cause significant morbidity and mortality worldwide. To date, no vaccines or antiviral therapeutics have been approved for combating DENV-associated disease. In this paper, we describe a class of tricyclic small-molecule compounds-dihydrodibenzothiepines (DHBTs), identified through high-throughput screening-with potent inhibitory activity against DENV serotype 2. SKI-417616, a highly active representative of this class, displayed activity against all four serotypes of DENV, as well as against a related flavivirus, West Nile virus (WNV), and an alphavirus, Sindbis virus (SINV). This compound was characterized to determine its mechanism of antiviral activity. Investigation of the stage of the viral life cycle affected revealed that an early event in the life cycle is inhibited. Due to the structural similarity of the DHBTs to known antagonists of the dopamine and serotonin receptors, we explored the roles of two of these receptors, serotonin receptor 2A (5HTR2A) and the D4 dopamine receptor (DRD4), in DENV infection. Antagonism of DRD4 and subsequent downstream phosphorylation of epidermal growth factor receptor (EGFR)-related kinase (ERK) were found to impact DENV infection negatively, and blockade of signaling through this network was confirmed as the mechanism of anti-DENV activity for this class of compounds. The dengue viruses are mosquito-borne, reemerging human pathogens that are the etiological agents of a spectrum of febrile diseases. Currently, there are no approved therapeutic treatments for dengue-associated disease, nor is there a vaccine. This study identifies a small molecule, SKI-417616, with potent anti-dengue virus activity. Further analysis revealed that SKI-417616 acts through antagonism of the host cell dopamine D4 receptor and subsequent repression of the ERK phosphorylation pathway. These results suggest that SKI-417616, or other compounds targeting the same cellular pathways, may have therapeutic potential for the treatment of dengue virus infections.

Discovery of Potent and Selective Dipeptidyl Peptidase IV Inhibitors Derived from [beta]-Aminoamides Bearing Subsituted Triazolopiperazines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dooseop; Kowalchick, Jennifer E.; Brockunier, Linda L.

2008-06-30

A series of {beta}-aminoamides bearing triazolopiperazines have been discovered as potent, selective, and orally active dipeptidyl peptidase IV (DPP-4) inhibitors by extensive structure-activity relationship (SAR) studies around the triazolopiperazine moiety. Among these, compound 34b with excellent in vitro potency (IC{sub 50} = 4.3 nM) against DPP-4, high selectivity over other enzymes, and good pharmacokinetic profiles exhibited pronounced in vivo efficacy in an oral glucose tolerance test (OGTT) in lean mice. On the basis of these properties, compound 34b has been profiled in detail. Further refinement of the triazolopiperazines resulted in the discovery of a series of extremely potent compounds withmore » subnanomolar activity against DPP-4 (42b-49b), that is, 4-fluorobenzyl-substituted compound 46b, which is notable for its superior potency (IC{sub 50} = 0.18 nM). X-ray crystal structure determination of compounds 34b and 46b in complex with DPP-4 enzyme revealed that (R)-stereochemistry at the 8-position of triazolopiperazines is strongly preferred over (S) with respect to DPP-4 inhibition.« less

Identification of (E,E)-2,4-undecadienal from coriander (Coriandrum sativum L.) as a highly effective deodorant compound against the offensive odor of porcine large intestine.

PubMed

Ikeura, Hiromi; Kohara, Kaori; Li, Xin-Xian; Kobayashi, Fumiyuki; Hayata, Yasuyoshi

2010-10-27

The leaves of coriander ( Coriandrum sativum L.) exhibited a strong deodorizing effect against porcine internal organs (large intestine). The effective deodorizing compounds of coriander were identified by separating the volatile component of coriander, testing the effectiveness of each fraction against the offensive odor of porcine large intestine, and then identifying the compounds by GC-MS. The volatile component of coriander was first separated into six fractions (A-F) by preparative gas chromatography, and the deodorizing activity of each of these fractions against the offensive odor was measured. Fraction D, which showed the strongest deodorizing effect, was then separated into 12 subfractions by preparative GC. The deodorant activity of each subfraction was evaluated, and the deodorant compounds were identified by GC-MS. It was discovered that (E,E)-2,4-undecadienal was the most effective deodorizing compound. The deodorizing activity of (E,E)-2,4-undecadienal on the porcine large intestine increased as with concentration, reaching almost complete deodorizing ability at 10 ppb.

Bioactive Organocopper Compound from Pseudomonas aeruginosa Inhibits the Growth of Xanthomonas citri subsp. citri.

PubMed

de Oliveira, Admilton G; Spago, Flavia R; Simionato, Ane S; Navarro, Miguel O P; da Silva, Caroline S; Barazetti, André R; Cely, Martha V T; Tischer, Cesar A; San Martin, Juca A B; de Jesus Andrade, Célia G T; Novello, Cláudio R; Mello, João C P; Andrade, Galdino

2016-01-01

Citrus canker is a very destructive disease of citrus species. The challenge is to find new compounds that show strong antibiotic activity and low toxicity to plants and the environment. The objectives of the present study were (1) to extract, purify and evaluate the secondary metabolites with antibiotic activity produced by Pseudomonas aeruginosa LV strain in vitro against Xanthomonas citri subsp. citri (strain 306), (2) to determine the potential of semi-purified secondary metabolites in foliar application to control citrus canker under greenhouse conditions, and (3) to identify antibiotic activity in orange leaf mesophyll infected with strain 306, by electron microscopy. Two pure bioactive compounds were isolated, an organocopper antibiotic compound (OAC) and phenazine-1-carboxamide. Phenazine-1-carboxamide did not show any antibiotic activity under the experimental conditions used in this study. The OAC showed a high level of antibiotic activity with a minimum inhibitory concentration of 0.12 μg mL(-1). In greenhouse tests for control of citrus canker in orange trees, the semi-purified fraction F3d reduced lesion formation by about 97%. The concentration used was 500 times lower than that for the recommended commercial copper-based product. Electron microscopy showed that F3d altered the exopolysaccharide matrix and caused cell lysis of the pathogen inside the citrus canker lesions. These results suggest that secondary metabolites produced by inducing P. aeruginosa LV strain have a high potential to be used as a bioproduct to control citrus canker.

Bioactive Organocopper Compound from Pseudomonas aeruginosa Inhibits the Growth of Xanthomonas citri subsp. citri

PubMed Central

de Oliveira, Admilton G.; Spago, Flavia R.; Simionato, Ane S.; Navarro, Miguel O. P.; da Silva, Caroline S.; Barazetti, André R.; Cely, Martha V. T.; Tischer, Cesar A.; San Martin, Juca A. B.; de Jesus Andrade, Célia G. T.; Novello, Cláudio R.; Mello, João C. P.; Andrade, Galdino

2016-01-01

Citrus canker is a very destructive disease of citrus species. The challenge is to find new compounds that show strong antibiotic activity and low toxicity to plants and the environment. The objectives of the present study were (1) to extract, purify and evaluate the secondary metabolites with antibiotic activity produced by Pseudomonas aeruginosa LV strain in vitro against Xanthomonas citri subsp. citri (strain 306), (2) to determine the potential of semi-purified secondary metabolites in foliar application to control citrus canker under greenhouse conditions, and (3) to identify antibiotic activity in orange leaf mesophyll infected with strain 306, by electron microscopy. Two pure bioactive compounds were isolated, an organocopper antibiotic compound (OAC) and phenazine-1-carboxamide. Phenazine-1-carboxamide did not show any antibiotic activity under the experimental conditions used in this study. The OAC showed a high level of antibiotic activity with a minimum inhibitory concentration of 0.12 μg mL-1. In greenhouse tests for control of citrus canker in orange trees, the semi-purified fraction F3d reduced lesion formation by about 97%. The concentration used was 500 times lower than that for the recommended commercial copper-based product. Electron microscopy showed that F3d altered the exopolysaccharide matrix and caused cell lysis of the pathogen inside the citrus canker lesions. These results suggest that secondary metabolites produced by inducing P. aeruginosa LV strain have a high potential to be used as a bioproduct to control citrus canker. PMID:26903992

Effects of high salt stress on secondary metabolite production in the marine-derived fungus Spicaria elegans.

PubMed

Wang, Yi; Lu, Zhenyu; Sun, Kunlai; Zhu, Weiming

2011-01-01

To obtain structurally novel and bioactive natural compounds from marine-derived microorganisms, the effect of high salt stress on secondary metabolite production in the marine-derived fungal strain, Spicaria elegans KLA-03, was investigated. The organism, which was isolated from marine sediment, produced different secondary metabolites when cultured in 3% and 10% saline conditions. Four characteristic metabolites, only produced in the 10% salinity culture, were isolated, and their structures were identified as (2E,2'Z)-3,3'-(6,6'-dihydroxybiphenyl-3,3'-diyl)diacrylic acid (1), aspulvinone E (2), aspochalasin E (3) and trichodermamide B (6), according to their 1D and 2D NMR spectra. Compound 1 is a new compound. High salt stress may therefore be a promising means to induce the production of new and chlorinated compounds in halotolerant fungi. Compound 1 showed moderate antibacterial activity against Pseudomonas aeruginosa and Escherichia coli with minimum inhibitory concentration (MIC) values of 0.038 and 0.767 mM, respectively.

High-Throughput Screening based Identification of Small Molecule Antagonists of Integrin CD11b/CD18 Ligand Binding

PubMed Central

Faridi, Mohd Hafeez; Maiguel, Dony; Brown, Brock T.; Suyama, Eigo; Barth, Constantinos J.; Hedrick, Michael; Vasile, Stefan; Sergienko, Eduard; Schürer, Stephan; Gupta, Vineet

2010-01-01

Binding of leukocyte specific integrin CD11b/CD18 to its physiologic ligands is important for the development of normal immune response in vivo. Integrin CD11b/CD18 is also a key cellular effector of various inflammatory and autoimmune diseases. However, small molecules selectively inhibiting the function of integrin CD11b/CD18 are currently lacking. We used a newly described cell-based high throughput screening assay to identify a number of highly potent antagonists of integrin CD11b/CD18 from chemical libraries containing >100,000 unique compounds. Computational analyses suggest that the identified compounds cluster into several different chemical classes. A number of the newly identified compounds blocked adhesion of wild-type mouse neutrophils to CD11b/CD18 ligand fibrinogen. Mapping the most active compounds against chemical fingerprints of known antagonists of related integrin CD11a/CD18 shows little structural similarity, suggesting that the newly identified compounds are novel and unique. PMID:20188705

Key volatile compounds in red koji-shochu, a Monascus-fermented product, and their formation steps during fermentation.

PubMed

Rahayu, Yen Yen Sally; Yoshizaki, Yumiko; Yamaguchi, Keiko; Okutsu, Kayu; Futagami, Taiki; Tamaki, Hisanori; Sameshima, Yoshihiro; Takamine, Kazunori

2017-06-01

Red koji, which refers the solid culture grown koji mold on the steamed rice, is one of the ingredients of Asian fermented foods including the Japanese spirit shochu. This study was aimed at elucidating the characteristic flavor and key volatile compounds of red koji-shochu as well as the mechanism of their formation. Sensory evaluation showed that red koji-shochu has the distinctive flavors cheese, sour, milky, and oily. Fifteen key volatile compounds of red koji-shochu were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography, and by comparison between red koji-shochu and white koji-shochu, as another typical shochu. The mash analysis revealed that ketone compounds and short-chain acids derive from red koji. Furthermore, although other key compounds were produced by yeast, it is highly likely that their concentrations were affected directly or indirectly by the high activities of protease and lipase in red koji. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antitumor evaluation and 3D-QSAR studies of a new series of the spiropyrroloquinoline isoindolinone/aza-isoindolinone derivatives by comparative molecular field analysis (CoMFA).

PubMed

Sadeghzadeh, Masoud; Salahinejad, Maryam; Zarezadeh, Nahid; Ghandi, Mehdi; Baghery, Maryam Keshavarz

2017-11-01

In current study, antitumor activity of two series of the newly synthesized spiropyrroloquinoline isoindolinone and spiropyrroloquinoline aza-isoindolinone scaffolds was evaluated against three human breast normal and cancer cell lines (MCF-10A, MCF-7 and SK-BR-3) and compared with cytotoxicity values of doxorubicin and colchicine as the standard drugs. It was found that several compounds were endowed with cytotoxicity in the low micromolar range. Among these two series, compounds 6i, 6j, 6k and 7l, 7m, 7n, 7o containing 3-ethyl-1H-indole moiety were found to be highly effective against both cancer cell lines ranging from [Formula: see text] to [Formula: see text] in comparison with the corresponding analogs. Compared with human cancer cells, the most potent compounds did not show high cytotoxicity against human breast normal MCF-10A cells. Generally, most of the evaluated compounds 6a-l and 7a-o series showed more antitumor activity against SK-BR-3 than MCF-7 cells. Moreover, comparative molecular field analysis (CoMFA) as a popular tools of three-dimensional quantitative structure-activity relationship (3D-QSAR) studies was carried out on 27 spiropyrroloquinolineisoindolinone and spiropyrroloquinolineaza-isoindolinone derivatives with antitumor activity against on SK-BR-3 cells. The obtained CoMFA models showed statistically excellent performance, which also possessed good predictive ability for an external test set. The results confirm the important effect of molecular steric and electrostatic interactions of these compounds on in vitro cytotoxicity against SK-BR-3.

Discovery of 1,5-Disubstituted Pyridones: A New Class of Positive Allosteric Modulators of the Metabotropic Glutamate 2 Receptor

PubMed Central

2010-01-01

A series of 1,5-disubstituted pyridones was identified as positive allosteric modulators (PAMs) of the metabotropic glutamate receptor 2 (mGluR2) via high throughput screening (HTS). Subsequent SAR exploration led to the identification of several compounds with improved in vitro activity. Lead compound 8 was further profiled and found to attenuate the increase in PCP induced locomotor activity in mice. PMID:22778815

Confirmation of high-throughput screening data and novel mechanistic insights into VDR-xenobiotic interactions by orthogonal assays.

PubMed

Mahapatra, Debabrata; Franzosa, Jill A; Roell, Kyle; Kuenemann, Melaine Agnes; Houck, Keith A; Reif, David M; Fourches, Denis; Kullman, Seth W

2018-06-11

High throughput screening (HTS) programs have demonstrated that the Vitamin D receptor (VDR) is activated and/or antagonized by a wide range of structurally diverse chemicals. In this study, we examined the Tox21 qHTS data set generated against VDR for reproducibility and concordance and elucidated functional insights into VDR-xenobiotic interactions. Twenty-one potential VDR agonists and 19 VDR antagonists were identified from a subset of >400 compounds with putative VDR activity and examined for VDR functionality utilizing select orthogonal assays. Transient transactivation assay (TT) using a human VDR plasmid and Cyp24 luciferase reporter construct revealed 20/21 active VDR agonists and 18/19 active VDR antagonists. Mammalian-2-hybrid assay (M2H) was then used to evaluate VDR interactions with co-activators and co-regulators. With the exception of a select few compounds, VDR agonists exhibited significant recruitment of co-regulators and co-activators whereas antagonists exhibited considerable attenuation of recruitment by VDR. A unique set of compounds exhibiting synergistic activity in antagonist mode and no activity in agonist mode was identified. Cheminformatics modeling of VDR-ligand interactions were conducted and revealed selective ligand VDR interaction. Overall, data emphasizes the molecular complexity of ligand-mediated interactions with VDR and suggest that VDR transactivation may be a target site of action for diverse xenobiotics.

Synthesis and Biological Evaluation of 2-Methyl-4,5-Disubstituted Oxazoles as a Novel Class of Highly Potent Antitubulin Agents

NASA Astrophysics Data System (ADS)

Romagnoli, Romeo; Baraldi, Pier Giovanni; Prencipe, Filippo; Oliva, Paola; Baraldi, Stefania; Salvador, Maria Kimatrai; Lopez-Cara, Luisa Carlota; Brancale, Andrea; Ferla, Salvatore; Hamel, Ernest; Ronca, Roberto; Bortolozzi, Roberta; Mariotto, Elena; Porcù, Elena; Basso, Giuseppe; Viola, Giampietro

2017-04-01

Antimitotic agents that interfere with microtubule formation are one of the major classes of cytotoxic drugs for cancer treatment. Multiple 2-methyl-4-(3‧,4‧,5‧-trimethoxyphenyl)-5-substituted oxazoles and their related 4-substituted-5-(3‧,4‧,5‧-trimethoxyphenyl) regioisomeric derivatives designed as cis-constrained combretastatin A-4 (CA-4) analogues were synthesized and evaluated for their antiproliferative activity in vitro against a panel of cancer cell lines and, for selected highly active compounds, interaction with tubulin, cell cycle effects and in vivo potency. Both these series of compounds were characterized by the presence of a common 3‧,4‧,5‧-trimethoxyphenyl ring at either the C-4 or C-5 position of the 2-methyloxazole ring. Compounds 4g and 4i, bearing a m-fluoro-p-methoxyphenyl or p-ethoxyphenyl moiety at the 5-position of 2-methyloxazole nucleus, respectively, exhibited the greatest antiproliferative activity, with IC50 values of 0.35-4.6 nM (4g) and 0.5-20.2 nM (4i), which are similar to those obtained with CA-4. These compounds bound to the colchicine site of tubulin and inhibited tubulin polymerization at submicromolar concentrations. Furthermore, 4i strongly induced apoptosis that follows the mitochondrial pathway. In vivo, 4i in a mouse syngeneic model demonstrated high antitumor activity which significantly reduced the tumor mass at doses ten times lower than that required for CA-4P, suggesting that 4i warrants further evaluation as a potential anticancer drug.

Self Organizing Map-Based Classification of Cathepsin k and S Inhibitors with Different Selectivity Profiles Using Different Structural Molecular Fingerprints: Design and Application for Discovery of Novel Hits.

PubMed

Ihmaid, Saleh K; Ahmed, Hany E A; Zayed, Mohamed F; Abadleh, Mohammed M

2016-01-30

The main step in a successful drug discovery pipeline is the identification of small potent compounds that selectively bind to the target of interest with high affinity. However, there is still a shortage of efficient and accurate computational methods with powerful capability to study and hence predict compound selectivity properties. In this work, we propose an affordable machine learning method to perform compound selectivity classification and prediction. For this purpose, we have collected compounds with reported activity and built a selectivity database formed of 153 cathepsin K and S inhibitors that are considered of medicinal interest. This database has three compound sets, two K/S and S/K selective ones and one non-selective KS one. We have subjected this database to the selectivity classification tool 'Emergent Self-Organizing Maps' for exploring its capability to differentiate selective cathepsin inhibitors for one target over the other. The method exhibited good clustering performance for selective ligands with high accuracy (up to 100 %). Among the possibilites, BAPs and MACCS molecular structural fingerprints were used for such a classification. The results exhibited the ability of the method for structure-selectivity relationship interpretation and selectivity markers were identified for the design of further novel inhibitors with high activity and target selectivity.

Leishmanicidal compounds of Nectria pseudotrichia, an endophytic fungus isolated from the plant Caesalpinia echinata (Brazilwood)

PubMed Central

Cota, Betania Barros; Tunes, Luiza Guimarães; Maia, Daniela Nabak Bueno; Ramos, Jonas Pereira; de Oliveira, Djalma Menezes; Kohlhoff, Markus; Alves, Tânia Maria de Almeida; Souza-Fagundes, Elaine Maria; Campos, Fernanda Fraga; Zani, Carlos Leomar

2018-01-01

BACKGROUND In a screen of extracts from plants and fungi to detect antileishmanial activity, we found that the ethyl acetate extract of the fungus Nectria pseudotrichia, isolated from the tree Caesalpinia echinata (Brazilwood), is a promising source of bioactive compounds. OBJECTIVES The aims of this study were to isolate and determine the chemical structures of the compounds responsible for the antileishmanial activity of the organic extract from N. pseudotrichia. METHODS Compounds were isolated by chromatographic fractionation using semi-preparative high-performance liquid chromatography, and their chemical structures were determined by analytical and spectral data and by comparison with published data. The antileishmanial activity of the isolated compounds was evaluated in intracellular amastigote forms of Leishmania (Viannia) braziliensis expressing firefly luciferase as reporter gene, and cytotoxicity was determined in Vero and THP-1 mammalian cell lines by MTT assay. FINDINGS Fractionation of the extract yielded seven compounds: 10-acetyl trichoderonic acid A (1), 6′-acetoxy-piliformic acid (2), 5′,6′-dehydropiliformic acid (3), piliformic acid (4), hydroheptelidic acid (5), xylaric acid D (6), and cytochalasin D (7). Compounds 1, 2 and 3 are reported here for the first time. Compounds 1, 2, and 5 were more active, with IC50 values of 21.4, 28.3, and 24.8 µM, respectively, and showed low toxicity to Vero and THP-1 cells. MAIN CONCLUSIONS N. pseudotrichia produces secondary metabolites that are more toxic to intracellular amastigote forms of L. (V.) braziliensis than to mammalian cells. PMID:29236928

Characterization of Compounds with Tumor-Cell Proliferation Inhibition Activity from Mushroom (Phellinus baumii) Mycelia Produced by Solid-State Fermentation.

PubMed

Zhang, Henan; Shao, Qian; Wang, Wenhan; Zhang, Jingsong; Zhang, Zhong; Liu, Yanfang; Yang, Yan

2017-04-27

The inhibition of tumor-cell proliferationbyan organicsolvent extract from the solid-state fermentation of Phellinus baumii mycelia inoculated in rice medium was investigated in vitro. The active compounds inhibiting tumor-cell proliferation were characterized. Results revealed that all (petroleum ether, chloroform, ethyl acetate, and butanol) fractions inhibited tumor-cell proliferation in a dose-dependent fashion. The ethyl acetate extract had the highest inhibitory effecton tumor-cell proliferation, and the butanol fraction had the lowest. Six compounds were isolated and purified from the ethyl acetate extract of P. baumii mycelia by the tandem application of silica-gel column chromatography (SGCC), high-speed countercurrent chromatography (HSCCC), and preparative HPLC. These compounds were identified by NMR and electrospray ionization-mass spectrometry (ESI-MS) spectroscopic methods as ergosterol (RF1), ergosta-7,22-dien-3β-yl pentadecanoate (RF3), 3,4-dihydroxy benzaldehyde(RF6), inoscavinA (RF7), baicalein(RF10), and 24-ethylcholesta-5,22-dien-3β-ol (RF13). To further clarify the activity of these compounds, the cell-proliferation-inhibition tests of these compounds on various tumor cells were carried out and evaluatedin vitro. Results suggested that compounds RF6, RF7, and RF10 had potent inhibition effects on the proliferation of a series of tumor cell lines, including K562, L1210, SW620, HepG2, LNCaP, and MCF-7cells. These findings indicated that P. baumii mycelia produced by solid-state fermentation in rice canbe used to obtain active compounds with the ability to inhibittumor-cell proliferation.

Antidiabetic and antihiperlipidemic effect of Andrographis paniculata (Burm. f.) Nees and andrographolide in high-fructose-fat-fed rats

PubMed Central

Nugroho, Agung Endro; Andrie, Mohamad; Warditiani, Ni Kadek; Siswanto, Eka; Pramono, Suwidjiyo; Lukitaningsih, Endang

2012-01-01

Objectives: Andrographis paniculata (Burm. f.) Nees originates from India and grows widely in many areas in Southeast Asian countries. Andrographis paniculata (Burm. f.) Nees has shown an antidiabetic effect in type 1 DM rats. The present study investigates the purified extract of the plant and its active compound andrographolide for antidiabetic and antihyperlipidemic effects in high-fructose-fat-fed rats, a model of type 2 DM rats. Materials and Methods: Hyperglycemia in rats was induced by high-fructose-fat diet containing 36% fructose, 15% lard, and 5% egg yolks in 0.36 g/200 gb.wt. 55 days. The rats were treated with the extract or test compound on the 50th day. Antidiabetic activity was measured by estimating mainly the pre– and postprandial blood glucose levels and other parameters such as cholesterol, LDL, triglyceride, and body weight. Results: The purified extract and andrographolide significantly (P<0.05) decreased the levels of blood glucose, triglyceride, and LDL compared to controls. However, no changes were observed in serum cholesterol and rat body weight. Metformin also showed similar effects on these parameters. Conclusions: Andrographis paniculata (Burm. f.) Nees or its active compound andrographolide showed hypoglycemic and hypolipidemic effects in high-fat-fructose-fed rat. PMID:22701250

Unique DC-SIGN clustering activity of a small glycomimetic: A lesson for ligand design.

PubMed

Sutkeviciute, Ieva; Thépaut, Michel; Sattin, Sara; Berzi, Angela; McGeagh, John; Grudinin, Sergei; Weiser, Jörg; Le Roy, Aline; Reina, Jose J; Rojo, Javier; Clerici, Mario; Bernardi, Anna; Ebel, Christine; Fieschi, Franck

2014-06-20

DC-SIGN is a dendritic cell-specific C-type lectin receptor that recognizes highly glycosylated ligands expressed on the surface of various pathogens. This receptor plays an important role in the early stages of many viral infections, including HIV, which makes it an interesting therapeutic target. Glycomimetic compounds are good drug candidates for DC-SIGN inhibition due to their high solubility, resistance to glycosidases, and nontoxicity. We studied the structural properties of the interaction of the tetrameric DC-SIGN extracellular domain (ECD), with two glycomimetic antagonists, a pseudomannobioside (1) and a linear pseudomannotrioside (2). Though the inhibitory potency of 2, as measured by SPR competition experiments, was 1 order of magnitude higher than that of 1, crystal structures of the complexes within the DC-SIGN carbohydrate recognition domain showed the same binding mode for both compounds. Moreover, when conjugated to multivalent scaffolds, the inhibitory potencies of these compounds became uniform. Combining isothermal titration microcalorimetry, analytical ultracentrifugation, and dynamic light scattering techniques to study DC-SIGN ECD interaction with these glycomimetics revealed that 2 is able, without any multivalent presentation, to cluster DC-SIGN tetramers leading to an artificially overestimated inhibitory potency. The use of multivalent scaffolds presenting 1 or 2 in HIV trans-infection inhibition assay confirms the loss of potency of 2 upon conjugation and the equal efficacy of chemically simpler compound 1. This study documents a unique case where, among two active compounds chemically derived, the compound with the lower apparent activity is the optimal lead for further drug development.

QSAR and docking studies on xanthone derivatives for anticancer activity targeting DNA topoisomerase IIα

PubMed Central

Alam, Sarfaraz; Khan, Feroz

2014-01-01

Due to the high mortality rate in India, the identification of novel molecules is important in the development of novel and potent anticancer drugs. Xanthones are natural constituents of plants in the families Bonnetiaceae and Clusiaceae, and comprise oxygenated heterocycles with a variety of biological activities along with an anticancer effect. To explore the anticancer compounds from xanthone derivatives, a quantitative structure activity relationship (QSAR) model was developed by the multiple linear regression method. The structure–activity relationship represented by the QSAR model yielded a high activity–descriptors relationship accuracy (84%) referred by regression coefficient (r2=0.84) and a high activity prediction accuracy (82%). Five molecular descriptors – dielectric energy, group count (hydroxyl), LogP (the logarithm of the partition coefficient between n-octanol and water), shape index basic (order 3), and the solvent-accessible surface area – were significantly correlated with anticancer activity. Using this QSAR model, a set of virtually designed xanthone derivatives was screened out. A molecular docking study was also carried out to predict the molecular interaction between proposed compounds and deoxyribonucleic acid (DNA) topoisomerase IIα. The pharmacokinetics parameters, such as absorption, distribution, metabolism, excretion, and toxicity, were also calculated, and later an appraisal of synthetic accessibility of organic compounds was carried out. The strategy used in this study may provide understanding in designing novel DNA topoisomerase IIα inhibitors, as well as for other cancer targets. PMID:24516330

Natural compounds isolated from Brazilian plants are potent inhibitors of hepatitis C virus replication in vitro.

PubMed

Jardim, A C G; Igloi, Z; Shimizu, J F; Santos, V A F F M; Felippe, L G; Mazzeu, B F; Amako, Y; Furlan, M; Harris, M; Rahal, P

2015-03-01

Compounds extracted from plants can provide an alternative approach to new therapies. They present characteristics such as high chemical diversity, lower cost of production and milder or inexistent side effects compared with conventional treatment. The Brazilian flora represents a vast, largely untapped, resource of potential antiviral compounds. In this study, we investigate the antiviral effects of a panel of natural compounds isolated from Brazilian plants species on hepatitis C virus (HCV) genome replication. To do this we used firefly luciferase-based HCV sub-genomic replicons of genotypes 2a (JFH-1), 1b and 3a and the compounds were assessed for their effects on both HCV replication and cellular toxicity. Initial screening of compounds was performed using the maximum non-toxic concentration and 4 compounds that exhibited a useful therapeutic index (favourable ratio of cytotoxicity to antiviral potency) were selected for extra analysis. The compounds APS (EC50=2.3μM), a natural alkaloid isolated from Maytrenus ilicifolia, and the lignans 3(∗)43 (EC50=4.0μM), 3(∗)20 (EC50=8.2μM) and 5(∗)362 (EC50=38.9μM) from Peperomia blanda dramatically inhibited HCV replication as judged by reductions in luciferase activity and HCV protein expression in both the subgenomic and infectious systems. We further show that these compounds are active against a daclatasvir resistance mutant subgenomic replicon. Consistent with inhibition of genome replication, production of infectious JFH-1 virus was significantly reduced by all 4 compounds. These data are the first description of Brazilian natural compounds possessing anti-HCV activity and further analyses are being performed in order to investigate the mode of action of those compounds. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

NASA Astrophysics Data System (ADS)

Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

2014-01-01

Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ˜0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds.

Graphene stabilized ultra-small CuNi nanocomposite with high activity and recyclability toward catalysing the reduction of aromatic nitro-compounds

NASA Astrophysics Data System (ADS)

Fang, Hao; Wen, Ming; Chen, Hanxing; Wu, Qingsheng; Li, Weiying

2015-12-01

Nowadays, it is of great significance and a challenge to design a noble-metal-free catalyst with high activity and a long lifetime for the reduction of aromatic nitro-compounds. Here, a 2D structured nanocomposite catalyst with graphene supported CuNi alloy nanoparticles (NPs) is prepared, and is promising for meeting the requirements of green chemistry. In this graphene/CuNi nanocomposite, the ultra-small CuNi nanoparticles (~2 nm) are evenly anchored on graphene sheets, which is not only a breakthrough in the structures, but also brings about an outstanding performance in activity and stability. Combined with a precise optimization of the alloy ratios, the reaction rate constant of graphene/Cu61Ni39 reached a high level of 0.13685 s-1, with a desirable selectivity as high as 99% for various aromatic nitro-compounds. What's more, the catalyst exhibited a unprecedented long lifetime because it could be recycled over 25 times without obvious performance decay or even a morphology change. This work showed the promise and great potential of noble-metal-free catalysts in green chemistry.Nowadays, it is of great significance and a challenge to design a noble-metal-free catalyst with high activity and a long lifetime for the reduction of aromatic nitro-compounds. Here, a 2D structured nanocomposite catalyst with graphene supported CuNi alloy nanoparticles (NPs) is prepared, and is promising for meeting the requirements of green chemistry. In this graphene/CuNi nanocomposite, the ultra-small CuNi nanoparticles (~2 nm) are evenly anchored on graphene sheets, which is not only a breakthrough in the structures, but also brings about an outstanding performance in activity and stability. Combined with a precise optimization of the alloy ratios, the reaction rate constant of graphene/Cu61Ni39 reached a high level of 0.13685 s-1, with a desirable selectivity as high as 99% for various aromatic nitro-compounds. What's more, the catalyst exhibited a unprecedented long lifetime because it could be recycled over 25 times without obvious performance decay or even a morphology change. This work showed the promise and great potential of noble-metal-free catalysts in green chemistry. Electronic supplementary information (ESI) available: Detailed SEM and TEM images, XRD patterns, XPS, EDS, Raman spectra, gas chromatograms, TG analyses, UV-vis spectra, and reaction rate constant tables. See DOI: 10.1039/c5nr05016b

Use of hypometabolic TRIS extenders and high cooling rate refrigeration for cryopreservation of stallion sperm: presence and sensitivity of 5' AMP-activated protein kinase (AMPK).

PubMed

Córdova, Alex; Strobel, Pablo; Vallejo, Andrés; Valenzuela, Pamela; Ulloa, Omar; Burgos, Rafael A; Menarim, Bruno; Rodríguez-Gil, Joan Enric; Ratto, Marcelo; Ramírez-Reveco, Alfredo

2014-12-01

This study evaluated the effect of the use of hypometabolic TRIS extenders in the presence or the absence of AMPK activators as well as the utilization of high cooling rates in the refrigeration step on the freezability of stallion sperm. Twelve ejaculates were cryopreserved using Botucrio® as a control extender and a basic TRIS extender (HM-0) separately supplemented with 10 mM metformin, 2mM 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR), 2 mM Adenosine monophosphate (AMP), 40 μM compound C AMPK inhibitor or 2 mM AMP+40 μM compound C. Our results showed that the utilization of a hypometabolic TRIS extender supplemented or not with AMP or metformin significantly improves stallion sperm freezability when compared with a commercial extender. Additionally, high cooling rates do not affect stallion sperm quality after cooling and post-thawing. Finally, stallion spermatozoa present several putative AMPK sperm isoforms that do not seem to respond to classical activators, but do respond to the Compound C inhibitor. Copyright © 2014 Elsevier Inc. All rights reserved.

In-vitro antiviral efficacy of ribavirin and interferon-alpha against canine distemper virus.

PubMed

Carvalho, Otávio V; Saraiva, Giuliana L; Ferreira, Caroline G T; Felix, Daniele M; Fietto, Juliana L R; Bressan, Gustavo C; Almeida, Márcia R; Silva Júnior, Abelardo

2014-10-01

Canine distemper is a highly contagious disease with high incidence and lethality in the canine population. The objective of this study was to evaluate the efficacy of antiviral action with ribavirin (RBV), interferon-alpha (IFNα), and combinations of RBV and IFNα against canine distemper virus (CDV). Vero cells inoculated with CDV were treated with RBV, IFNα, and combinations of these drugs. The efficacy to inhibit viral replication was evaluated by adding the compounds at different times to determine which step of the viral replicative process was affected. Both drugs were effective against CDV in vitro. The IFNα was the most active compound, with an average IC50 (50% inhibitory concentration) value lower than the IC50 of the RBV. Ribavirin (RBV) was more selective than IFNα, however, and neither drug showed extracellular antiviral activity. The combination of RBV and IFNα exhibited antiviral activity for the intra- and extracellular stages of the replicative cycle of CDV, although the intracellular viral inhibition was higher. Both RBV and IFNα showed high antiviral efficacy against CDV, and furthermore, RBV + IFNα combinations have shown greater interference range in viral infectivity. These compounds could potentially be used to treat clinical disease associated with CDV infection.

In-vitro antiviral efficacy of ribavirin and interferon-alpha against canine distemper virus

PubMed Central

Carvalho, Otávio V.; Saraiva, Giuliana L.; Ferreira, Caroline G.T.; Felix, Daniele M.; Fietto, Juliana L.R.; Bressan, Gustavo C.; Almeida, Márcia R.; Silva Júnior, Abelardo

2014-01-01

Canine distemper is a highly contagious disease with high incidence and lethality in the canine population. The objective of this study was to evaluate the efficacy of antiviral action with ribavirin (RBV), interferon-alpha (IFNα), and combinations of RBV and IFNα against canine distemper virus (CDV). Vero cells inoculated with CDV were treated with RBV, IFNα, and combinations of these drugs. The efficacy to inhibit viral replication was evaluated by adding the compounds at different times to determine which step of the viral replicative process was affected. Both drugs were effective against CDV in vitro. The IFNα was the most active compound, with an average IC50 (50% inhibitory concentration) value lower than the IC50 of the RBV. Ribavirin (RBV) was more selective than IFNα, however, and neither drug showed extracellular antiviral activity. The combination of RBV and IFNα exhibited antiviral activity for the intra- and extracellular stages of the replicative cycle of CDV, although the intracellular viral inhibition was higher. Both RBV and IFNα showed high antiviral efficacy against CDV, and furthermore, RBV + IFNα combinations have shown greater interference range in viral infectivity. These compounds could potentially be used to treat clinical disease associated with CDV infection. PMID:25355997

Phenolic Compounds Present Schinus terebinthifolius Raddi Influence the Lowering of Blood Pressure in Rats.

PubMed

de Lima Glória, Lorena; Barreto de Souza Arantes, Mariana; Menezes de Faria Pereira, Silvia; de Souza Vieira, Guilherme; Xavier Martins, Camilla; Ribeiro de Carvalho Junior, Almir; Antunes, Fernanda; Braz-Filho, Raimundo; José Curcino Vieira, Ivo; Leandro da Cruz, Larissa; Siqueira de Almeida Chaves, Douglas; de Paiva Freitas, Silvério; Barros de Oliveira, Daniela

2017-10-23

This study identified two phenolic compounds in Schinus terebinthifolius Raddi fruits: naringenin (first report in this species) and gallic acid. Their structures were elucidated by nuclear magnetic resonance (NMR) data (¹H-, 13 C-NMR) and a high-performance liquid chromatography (HPLC) technique. A high content of phenolics (659.21 mg of gallic acid equivalents/g of sample-Folin-Ciocalteau method) and total flavonoids (140.69 mg of rutin equivalents/g of sample-aluminum chloride method) were quantified in S. terebinthifolius , as well as high antioxidant activity (77.47%-2,2-diphenyl-1-picrylhydrazyl, DPPH method). The antihypertensive activity related to its phenolic content was investigated. After intravenous infusion in Wistar rats, these phenolics significantly reduced ( p < 0.05) the systolic, median, and diastolic arterial pressures of individuals. The rotarod test was performed to determine the mechanism of action of the sample vasorelaxant effect. It was found that its action exceeded that of the positive control used (diazepam). This confirmed the vasodilatory activity exerted by S. terebinthifolius fruits is related to the phenolic compounds present in the plant, which are potent antioxidants and inhibit oxidative stress, mainly in the central nervous system.

Antibacterial activity of 3-methylbenzo[d]thiazol-methylquinolinium derivatives and study of their action mechanism.

PubMed

Sun, Ning; Du, Ruo-Lan; Zheng, Yuan-Yuan; Guo, Qi; Cai, Sen-Yuan; Liu, Zhi-Hua; Fang, Zhi-Yuan; Yuan, Wen-Chang; Liu, Ting; Li, Xiao-Mei; Lu, Yu-Jing; Wong, Kwok-Yin

2018-12-01

The increasing incidence of multidrug resistant bacterial infection renders an urgent need for the development of new antibiotics. To develop small molecules disturbing FtsZ activity has been recognized as promising approach to search for antibacterial of high potency systematically. Herein, a series of novel quinolinium derivatives were synthesized and their antibacterial activities were investigated. The compounds show strong antibacterial activities against different bacteria strains including MRSA, VRE and NDM-1 Escherichia coli. Among these derivatives, a compound bearing a 4-fluorophenyl group (A2) exhibited a superior antibacterial activity and its MICs to the drug-resistant strains are found lower than those of methicillin and vancomycin. The biological results suggest that these quinolinium derivatives can disrupt the GTPase activity and dynamic assembly of FtsZ, and thus inhibit bacterial cell division and then cause bacterial cell death. These compounds deserve further evaluation for the development of new antibacterial agents targeting FtsZ.

Quinazoline derivative from indigenous isolate, Nocardiopsis alba inhibits human telomerase enzyme.

PubMed

Kiran, K G; Thandeeswaran, M; Ayub Nawaz, K A; Easwaran, M; Jayagopi, K K; Ebrahimi, L; Palaniswamy, M; Mahendran, R; Angayarkanni, J

2016-12-01

Aim of this study was isolation and screening of various secondary metabolites produced by indigenous isolates of soil Actinomycetes for human telomerase inhibitory activity. Extracellular extract from culture suspension of various soil Actinomycetes species were tested for telomerase inhibitory activity. The organism which produced telomerase inhibitor was identified by 16S rRNA gene sequencing. The active fraction was purified by HPLC and analysed by GC-MS to identify the compound. In GC-MS analysis, the active principle was identified as 3-[4'-(2″-chlorophenyl)-2'-thiazolyl]-2,4-dioxo-1,2,3,4-tetrahydro quinazoline. The G-quadruplex stabilizing ability of the compound was checked by molecular docking and simulation experiments with G-quadruplex model (PDB ID-1L1H). The selective binding ability of the compound with G-quadruplex over Dickerson-Drew dodecamer DNA structures showed that the compound possess high selectivity towards G-quadruplex. Quinazoline derivative isolated from an indigenous strain of Nocardiopsis alba inhibited telomerase. Molecular docking and simulation studies predicted that this compound is a strong stabilizer of G-quadruplex conformation. It also showed a preferable binding to G-quadruplex DNA over normal DNA duplex. This particular compound can be suggested as a suitable compound for developing a future anticancer drug. The selectivity towards G-quadruplex over normal DNA duplex gives a clue that it is likely to show lower cytotoxicity in normal cells. © 2016 The Society for Applied Microbiology.

Antimicrobial and Insecticidal: Cyclic Lipopeptides and Hydrogen Cyanide Produced by Plant-Beneficial Pseudomonas Strains CHA0, CMR12a, and PCL1391 Contribute to Insect Killing

PubMed Central

Flury, Pascale; Vesga, Pilar; Péchy-Tarr, Maria; Aellen, Nora; Dennert, Francesca; Hofer, Nicolas; Kupferschmied, Karent P.; Kupferschmied, Peter; Metla, Zane; Ma, Zongwang; Siegfried, Sandra; de Weert, Sandra; Bloemberg, Guido; Höfte, Monica; Keel, Christoph J.; Maurhofer, Monika

2017-01-01

Particular groups of plant-beneficial fluorescent pseudomonads are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. The mechanisms by which the bacteria manage to infest this alternative host, to overcome its immune system, and to ultimately kill the insect are still largely unknown. However, the investigation of the few virulence factors discovered so far, points to a highly multifactorial nature of insecticidal activity. Antimicrobial compounds produced by fluorescent pseudomonads are effective weapons against a vast diversity of organisms such as fungi, oomycetes, nematodes, and protozoa. Here, we investigated whether these compounds also contribute to insecticidal activity. We tested mutants of the highly insecticidal strains Pseudomonas protegens CHA0, Pseudomonas chlororaphis PCL1391, and Pseudomonas sp. CMR12a, defective for individual or multiple antimicrobial compounds, for injectable and oral activity against lepidopteran insect larvae. Moreover, we studied expression of biosynthesis genes for these antimicrobial compounds for the first time in insects. Our survey revealed that hydrogen cyanide and different types of cyclic lipopeptides contribute to insecticidal activity. Hydrogen cyanide was essential to full virulence of CHA0 and PCL1391 directly injected into the hemolymph. The cyclic lipopeptide orfamide produced by CHA0 and CMR12a was mainly important in oral infections. Mutants of CMR12a and PCL1391 impaired in the production of the cyclic lipopeptides sessilin and clp1391, respectively, showed reduced virulence in injection and feeding experiments. Although virulence of mutants lacking one or several of the other antimicrobial compounds, i.e., 2,4-diacetylphloroglucinol, phenazines, pyrrolnitrin, or pyoluteorin, was not reduced, these metabolites might still play a role in an insect background since all investigated biosynthetic genes for antimicrobial compounds of strain CHA0 were expressed at some point during insect infection. In summary, our study identified new factors contributing to insecticidal activity and extends the diverse functions of antimicrobial compounds produced by fluorescent pseudomonads from the plant environment to the insect host. PMID:28217113

Phytochemical screening and in-vitro antioxidant activity isolated bioactive compounds from Tridax procumbens Linn.

PubMed

Saxena, Manjusha; Mir, Abrar Hussain; Sharma, Manik; Malla, Mohd Yousu; Qureshi, Sumeerah; Mir, Mohd Iqbal; Chaturvedi, Yogesh

2013-12-15

Tridax procumbens L., Asteraceae, has been extensively used for various ailments in the Ayurvedic system of medicine. Previous studies have revealed remarkable phytoconstituents from Tridax procumbens L. with significant antioxidant activity. The aim of the present study is to measure the anti-DPPH activity of the purified isolated compounds from n butanol soluble part and ethyl acetate soluble part of successive methanolic extract of Tridax procumbens L. We thus quantified the total phenolic and total flavonoids in different purified isolated compounds, the whole of the tests were evaluated with a sample cone. of 100 microg mL(-1) and were determined spectrophotometrically using Folin-ciocaltue and AlCl3 reagents, respectively. DPPH (1,1-diphenyl, 2-picryl hydrazyl) assay was used to determine the in vitro antioxidant activity of different isolated compounds. Isolated compounds, one from ethyl acetate soluble part (EF-I) and one from n butanol soluble part (BF-II) were reported to possess a significant anti DPPH activity with lowest IC50 values 67.26 and 80.90 microg mL(-1), respectively while comparable to standard ascorbic acid with IC50 value of 59.62 microg mL(-1), due to the high concentration of phenols 146.4 microg mL(-1) from EF-I and 142.2 microg mL(-1) from BF-II and flavonoids 48 and 42.5 microg mL(-1) found in EF-I and BF-II isolated compounds, respectively.

Antibacterial activity of extracellular compounds produced by a Pseudomonas strain against methicillin-resistant Staphylococcus aureus (MRSA) strains

PubMed Central

2013-01-01

Background The emergence of multidrug-resistant bacteria is a world health problem. Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) strains, is one of the most important human pathogens associated with hospital and community-acquired infections. The aim of this work was to evaluate the antibacterial activity of a Pseudomonas aeruginosa-derived compound against MRSA strains. Methods Thirty clinical MRSA strains were isolated, and three standard MRSA strains were evaluated. The extracellular compounds were purified by vacuum liquid chromatography. Evaluation of antibacterial activity was performed by agar diffusion technique, determination of the minimal inhibitory concentration, curve of growth and viability and scanning electron microscopy. Interaction of an extracellular compound with silver nanoparticle was studied to evaluate antibacterial effect. Results The F3 (ethyl acetate) and F3d (dichloromethane- ethyl acetate) fractions demonstrated antibacterial activity against the MRSA strains. Phenazine-1-carboxamide was identified and purified from the F3d fraction and demonstrated slight antibacterial activity against MRSA, and synergic effect when combined with silver nanoparticles produced by Fusarium oxysporum. Organohalogen compound was purified from this fraction showing high antibacterial effect. Using scanning electron microscopy, we show that the F3d fraction caused morphological changes to the cell wall of the MRSA strains. Conclusions These results suggest that P. aeruginosa-produced compounds such as phenazines have inhibitory effects against MRSA and may be a good alternative treatment to control infections caused by MRSA. PMID:23773484

Inhibition of Mutated Isocitrate Dehydrogenase 1 in Cancer.

PubMed

Wu, Fangrui; Cheng, Gang; Yao, Yuan; Kogiso, Mari; Jiang, Hong; Li, Xiao-Nan; Song, Yongcheng

2018-05-23

R132H mutation of isocitrate dehydrogenase 1 (IDH1) are found in ~75% of low-grade gliomas and secondary glioblastomas as well as in several other types of cancer. More chemotypes of inhibitors of IDH1(R132H) are therefore needed. To develop a new class of IDH1(R132H) inhibitors as potent antitumor agents. A biochemical assay was developed to find inhibitors of IDH1(R132H) mutant enzyme. Chemical synthesis and structure activity relationship studies were used to find compounds with improved potency. Antitumor activities of selected compounds were evaluated. A series of aromatic sulfonamide compounds were found to be novel, potent inhibitors of IDH1(R132H) with Ki values as low as 0.6 µM. Structure activity relationships of these compounds are discussed. Enzyme kinetics studies showed that one compound is a competitive inhibitor against the substrate α-KG and a non-competitive inhibitor against the cofactor NADPH. Several inhibitors were found to have no activity against wild-type IDH1, showing a high selectivity. Two potent inhibitors exhibited strong activity against proliferation of BT142 glioma cells with IDH1 R132H mutation, while these compounds did not significantly affect growth of glioma cells without IDH1 mutation. This novel series of IDH1(R132H) inhibitors have potential to be further developed for the treatment of glioma with IDH1 mutation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Regulatory domain phosphorylation to distinguish the mechanistic basis underlying acute CFTR modulators

PubMed Central

Pyle, Louise C.; Ehrhardt, Annette; Mitchell, Lisa High; Fan, LiJuan; Ren, Aixia; Naren, Anjaparavanda P.; Li, Yao; Clancy, J. P.; Bolger, Graeme B.; Sorscher, Eric J.

2011-01-01

Modulator compounds intended to overcome disease-causing mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) show significant promise in clinical testing for cystic fibrosis. However, the mechanism(s) of action underlying these compounds are not fully understood. Activation of CFTR ion transport requires PKA-regulated phosphorylation of the regulatory domain (R-D) and dimerization of the nucleotide binding domains. Using a newly developed assay, we evaluated nine compounds including both CFTR potentatiators and activators discovered via various high-throughput screening strategies to acutely augment CFTR activity. We found considerable differences in the effects on R-D phosphorylation. Some (including UCCF-152) stimulated robust phosphorylation, and others had little effect (e.g., VRT-532 and VX-770). We then compared CFTR activation by UCCF-152 and VRT-532 in Ussing chamber studies using two epithelial models, CFBE41o− and Fischer rat thyroid cells, expressing various CFTR forms. UCCF-152 activated wild-type-, G551D-, and rescued F508del-CFTR currents but did not potentiate cAMP-mediated CFTR activation. In contrast, VRT-532 moderately activated CFTR short-circuit current and strongly potentiated forskolin-mediated current. Combined with the result that UCCF-152, but not VRT-532 or VX-770, acts by increasing CFTR R-D phosphorylation, these findings indicate that potentiation of endogenous cAMP-mediated activation of mutant CFTR is not due to a pathway involving augmented R-D phosphorylation. This study presents an assay useful to distinguish preclinical compounds by a crucial mechanism underlying CFTR activation, delineates two types of compound able to acutely augment CFTR activity (e.g., activators and potentiators), and demonstrates that a number of different mechanisms can be successfully employed to activate mutant CFTR. PMID:21724857

The new generation dihydropyridine type calcium blockers, bearing 4-phenyl oxypropanolamine, display alpha-/beta-adrenoceptor antagonist and long-acting antihypertensive activities.

PubMed

Liang, Jhy-Chong; Yeh, Jwu-Lai; Wang, Chia-Sui; Liou, Shwu-Fen; Tsai, Chieh-Ho; Chen, Ing-Jun

2002-03-01

A new series of dihydropyridine derivatives, bearing oxypropanolamine moiety on phenyl ring at the 4-position of the dihydropyridine base, were prepared. Oxypropanolamine was synthesized by replacing the phenolic OH of vanillin or other compounds, having a phenyl aldehyde group, with epichlorohydrin, followed by cleavaging the obtained epoxide compounds with tert-butylamine, n-butylamine or 2-methoxy-1-oxyethylamino benzene (guaiacoxyethylamine), respectively. Obtained various oxypropanolamine compounds, still remaining a phenyl aldehyde moiety, were then performed by Hantzsch condensation reaction with methylacetoacetate or ethylacetoacetate, respectively, to give our new series of dihydropyridine linked with the 4-phenyl ring. These compounds were evaluated for inotropic, chronotropic, and aorta contractility that associated with calcium channel and adrenoceptor antagonist activities. Dihydropyridine derivatives that with oxypropanolamine side chain on their 4-phenyl ring associated alpha-/beta-adrenoceptor blocking activities created a new family of calcium entry and the third generation beta-adrenoceptor blockers. Optimizing this research to obtain more potent alpha-/beta-adrenoceptor blocking and long-acting antihypertensive oxypropanolamine on the 4-phenyl ring of dihydropyridine series compounds was thus accomplished and classified as third generation dihydropyridine type calcium channel blockers, in comparison with previous short-acting type nifedipine and long-acting type amlodipine. We concluded that compounds 1a, 1b and 1g showed not only markedly high calcium-antagonistic activity but also the highest antihypertensive effect; compounds 1b, 1c, 1f, 1g, 1i and 1j induced sustained antihypertensive effects are major and attributed to their calcium entry and alpha-adrenoceptor blocking activities in the blood vessel due to their introduction of 2-methoxy, 1-oxyethylamino benzene moiety in the side chain on the 4-phenyl ring of dihydropyridine. Bradycardiac effects of all the compounds 1a-1j resulted from calcium entry and beta-adrenoceptor blocking, which attenuate the sympathetic activation-associated reflex tachycardia in the heart. We selected compound 1b as candidate compound for further pharmacological and pre-clinical evaluation studies.

Rapid estimation of the oxidative activities of individual phenolics in crude plant extracts.

PubMed

Vihakas, Matti; Pälijärvi, Maija; Karonen, Maarit; Roininen, Heikki; Salminen, Juha-Pekka

2014-07-01

Previous studies of purified phenolic compounds have revealed that some phenolics, especially ellagitannins, can autoxidise under alkaline conditions, which predominate in the midgut of lepidopteran larvae. To facilitate screening for the pro-oxidant activities of all types of phenolic compounds from crude plant extracts, we developed a method that combined our recent spectrophotometric bioactivity method with an additional chromatographic step via UPLC-DAD-MS. This method allowed us to estimate the total pro-oxidant capacities of crude extracts from 12 plant species and to identify the individual phenolic compounds that were responsible for the detected activities. It was found that the pro-oxidant capacities of the plant species (i.e., the concentrations of the easily-oxidised phenolics) varied from 0 to 57 mg/g dry wt, representing from 0% to 46% of the total phenolics from different species. UPLC-DAD-MS analysis revealed that most flavonol and flavone glycosides were only slightly affected by alkaline conditions, thus indicating their low pro-oxidant activity. Interestingly, myricetin-type compounds differed from the other flavonoids, as their concentrations decreased strongly due to alkaline incubation. The same effect was detected for hydrolysable tannins and prodelphinidins, suggesting that a pyrogallol sub-structure could be a key structural component that partially explains their easy oxidation at high pH. Other types of phenolic compounds, such as hydroxycinnamic acids, were relatively active, as well. These findings demonstrate that this method displays the potential to identify most of the active and inactive pro-oxidant phenolic compounds in various plant species. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chemical characterisation of Nigerian red propolis and its biological activity against Trypanosoma Brucei.

PubMed

Omar, Ruwida M K; Igoli, John; Gray, Alexander I; Ebiloma, Godwin Unekwuojo; Clements, Carol; Fearnley, James; Ebel, Ru Angeli Edrada; Zhang, Tong; De Koning, Harry P; Watson, David G

2016-01-01

A previous study showed the unique character of Nigerian red propolis from Rivers State, Nigeria (RSN), with regards to chemical composition and activity against Trypanosoma brucei in comparison with other African propolis. To carry out fractionation and biological testing of Nigerian propolis in order to isolate compounds with anti-trypanosomal activity. To compare the composition of the RSN propolis with the composition of Brazilian red propolis. Profiling was carried out using HPLC-UV-ELSD and HPLC-Orbitrap-FTMS on extracts of two samples collected from RSN with data extraction using MZmine software. Isolation was carried out by normal phase and reversed phase MPLC. Elucidation of the compounds with a purity > 95% was performed by 1D/2D NMR HRMS and HRLC-MS(n) . Ten phenolic compounds were isolated or in the case of liquiritigenin partially purified. Data for nine of these correlated with literature reports of known compounds i.e. one isoflavanone, calycosin (1); two flavanones, liquiritigenin (2) and pinocembrin (5); an isoflavan, vestitol (3); a pterocarpan, medicarpin (4); two prenylflavanones, 8-prenylnaringenin (7) and 6-prenylnaringenin (8); and two geranyl flavonoids, propolin D (9) and macarangin (10). The tenth was elucidated as a previously undescribed dihydrobenzofuran (6). The isolated compounds were tested against Trypanosoma brucei and displayed moderate to high activity. Some of the compounds tested had similar activity against wild type T. brucei and two strains displaying pentamidine resistance. Nigerian propolis from RSN has some similarities with Brazilian red propolis. The propolis displayed anti-trypanosomal activity at a potentially useful level. Copyright © 2015 John Wiley & Sons, Ltd.

Synthesis of Naphthyl-, Quinolin- and Anthracenyl Analogues of Clofibric Acid as PPARα Agonists.

PubMed

Giampietro, Letizia; Ammazzalorso, Alessandra; Bruno, Isabella; Carradori, Simone; De Filippis, Barbara; Fantacuzzi, Marialuigia; Giancristofaro, Antonella; Maccallini, Cristina; Amoroso, Rosa

2016-03-01

PPARα is a ligand activated transcription factor belonging to the nuclear receptor subfamily, involved in fatty acid metabolism in tissues with high oxidative rates such as muscle, heart and liver. PPARα activation is important in steatosis, inflammation and fibrosis in preclinical models of non-alcoholic fatty liver disease identifying a new potential therapeutic area. In this work, three series of clofibric acid analogues conjugated with naphthyl, quinolin, chloroquinolin and anthracenyl scaffolds were synthesized. In an effort to obtain new compounds active as PPARα agonists, these molecules were evaluated for PPARα transactivation activity. Naphthyl and quinolin derivatives showed a good activation of PPARα; noteworthy, optically active naphthyl derivatives activated PPARα better than corresponding parent compound. © 2015 John Wiley & Sons A/S.

Starch Applications for Delivery Systems

NASA Astrophysics Data System (ADS)

Li, Jason

2013-03-01

Starch is one of the most abundant and economical renewable biopolymers in nature. Starch molecules are high molecular weight polymers of D-glucose linked by α-(1,4) and α-(1,6) glycosidic bonds, forming linear (amylose) and branched (amylopectin) structures. Octenyl succinic anhydride modified starches (OSA-starch) are designed by carefully choosing a proper starch source, path and degree of modification. This enables emulsion and micro-encapsulation delivery systems for oil based flavors, micronutrients, fragrance, and pharmaceutical actives. A large percentage of flavors are encapsulated by spray drying in today's industry due to its high throughput. However, spray drying encapsulation faces constant challenges with retention of volatile compounds, oxidation of sensitive compound, and manufacturing yield. Specialty OSA-starches were developed suitable for the complex dynamics in spray drying and to provide high encapsulation efficiency and high microcapsule quality. The OSA starch surface activity, low viscosity and film forming capability contribute to high volatile retention and low active oxidation. OSA starches exhibit superior performance, especially in high solids and high oil load encapsulations compared with other hydrocolloids. The submission is based on research and development of Ingredion

Physicochemical characteristics of structurally determined metabolite-protein and drug-protein binding events with respect to binding specificity.

PubMed

Korkuć, Paula; Walther, Dirk

2015-01-01

To better understand and ultimately predict both the metabolic activities as well as the signaling functions of metabolites, a detailed understanding of the physical interactions of metabolites with proteins is highly desirable. Focusing in particular on protein binding specificity vs. promiscuity, we performed a comprehensive analysis of the physicochemical properties of compound-protein binding events as reported in the Protein Data Bank (PDB). We compared the molecular and structural characteristics obtained for metabolites to those of the well-studied interactions of drug compounds with proteins. Promiscuously binding metabolites and drugs are characterized by low molecular weight and high structural flexibility. Unlike reported for drug compounds, low rather than high hydrophobicity appears associated, albeit weakly, with promiscuous binding for the metabolite set investigated in this study. Across several physicochemical properties, drug compounds exhibit characteristic binding propensities that are distinguishable from those associated with metabolites. Prediction of target diversity and compound promiscuity using physicochemical properties was possible at modest accuracy levels only, but was consistently better for drugs than for metabolites. Compound properties capturing structural flexibility and hydrogen-bond formation descriptors proved most informative in PLS-based prediction models. With regard to diversity of enzymatic activities of the respective metabolite target enzymes, the metabolites benzylsuccinate, hypoxanthine, trimethylamine N-oxide, oleoylglycerol, and resorcinol showed very narrow process involvement, while glycine, imidazole, tryptophan, succinate, and glutathione were identified to possess broad enzymatic reaction scopes. Promiscuous metabolites were found to mainly serve as general energy currency compounds, but were identified to also be involved in signaling processes and to appear in diverse organismal systems (digestive and nervous system) suggesting specific molecular and physiological roles of promiscuous metabolites.