Gas-phase cationic benzoylation of ambient aromatic substrates studied with the decay technique

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

Occhiucci, G.; Cacace, F.; Speranza, M.

1986-03-05

The gas-phase benzoylation of typical ambient aromatic substrates PhY (Y = OH, OMe, and NH/sub 2/) has been investigated by a combination of the decay technique and of FT ICR mass spectrometry. Labeled phenylium ions, C/sub 6/X/sub 5//sup +/ (X = H and T), from the decay of multiply tritiated benzene, C/sub 6/X/sub 6/, have been allowed to react with excess CO-containing traces of PhY (Y = OH, OMe, and NH/sub 2/), in the pressure range from 90 to 650 torr. Radio GLC and HPLC of the tritiated products demonstrate two competitive reaction channels, i.e., phenylation and benzoylation of themore » aromatic substrates. The results indicate a sharp kinetic bias of the gaseous phenylium ions for the aromatic substrates, measured by an apparent k/sub CO//k/sub PhY/ ratio of 0.12 (Y = OH), 0.13 (Y = OMe), and 0.04 (Y = NH/sub 2/) in the systems at nearly atmospheric pressure. Gas-phase benzoylation displays a high intramolecular selectivity, occurring exclusively at the n-type center of PhOH and PhNH/sub 2/. In the case of PhOMe, appreciable ring benzoylation is observed, characterized by a remarkably high (up to 30:1) bias for the para position. The mechanistic features of the gas-phase benzoylation and phenylation processes, deduced from the decay and the ICR experiments, are discussed and compared with those of related aromatic acylation and alkylation reactions occurring in the dilute gas state. 30 references, 2 tables.« less

Profile of clindamycin phosphate 1.2%/benzoyl peroxide 3.75% aqueous gel for the treatment of acne vulgaris

PubMed Central

Nguyen, Tuyet A; Eichenfield, Lawrence F

2015-01-01

Acne vulgaris is a common and chronic skin disease, and is a frequent source of morbidity for affected patients. Treatment of acne vulgaris is often difficult due to the multifactorial nature of this disease. Combination therapy, such as that containing clindamycin and benzoyl peroxide, has become the standard of care. Several fixed formulations of clindamycin 1% and benzoyl peroxide of varying concentrations are available and have been used with considerable success. The major limitation is irritation and dryness from higher concentrations of benzoyl peroxide, and a combination providing optimal efficacy and tolerability has yet to be determined. Recently, a clindamycin and benzoyl peroxide 3.75% fixed combination formulation was developed. Studies have suggested that this formulation may be a safe and effective treatment regimen for patients with acne vulgaris. Here, we provide a brief review of acne pathogenesis, benzoyl peroxide and clindamycin, and profile a new Clindamycin-BP 3.75% fixed combination gel for the treatment of moderate-to-severe acne vulgaris. PMID:26604811

75 FR 9767 - Classification of Benzoyl Peroxide as Safe and Effective and Revision of Labeling to Drug Facts...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-04

... photocarcinogenicity studies at that time. We also proposed labeling to communicate the results of the animal studies... promoter, benzoyl peroxide, at multiple times throughout the remainder of the study. Because tumor... to the backs 5 times per week for 50 weeks. In this study, benzoyl peroxide was not a tumor promoter...

Formulation and Characterization of Benzoyl Peroxide Gellified Emulsions

PubMed Central

Thakur, Naresh Kumar; Bharti, Pratibha; Mahant, Sheefali; Rao, Rekha

2012-01-01

The present investigation was carried out with the objective of formulating a gellified emulsion of benzoyl peroxide, an anti-acne agent. The formulations were prepared using four different vegetable oils, viz. almond oil, jojoba oil, sesame oil, and wheat germ oil, owing to their emollient properties. The idea was to overcome the skin irritation and dryness caused by benzoyl peroxide, making the formulation more tolerable. The gellified emulsions were characterized for their homogeneity, rheology, spreadability, drug content, and stability. In vitro permeation studies were performed to check the drug permeation through rat skin. The formulations were evaluated for their antimicrobial activity, as well as their acute skin irritation potential. The results were compared with those obtained for the marketed formulation. Later, the histopathological examination of the skin treated with various formulations was carried out. Formulation F3 was found to have caused a very mild dysplastic change to the epidermis. On the other hand, the marketed formulation led to the greatest dysplastic change. Hence, it was concluded that formulation F3, containing sesame oil (6%w/w), was the optimized formulation. It exhibited the maximum drug release and anti-microbial activity, in addition to the least skin irritation potential. PMID:23264949

Benzoate Metabolism Intermediate Benzoyl Coenzyme A Affects Gentisate Pathway Regulation in Comamonas testosteroni

PubMed Central

Chen, Dong-Wei; Zhang, Yun; Jiang, Cheng-Ying

2014-01-01

A previous study showed that benzoate was catabolized via a coenzyme A (CoA)-dependent epoxide pathway in Azoarcus evansii (R. Niemetz, U. Altenschmidt, S. Brucker, and G. Fuchs, Eur. J. Biochem. 227:161-168, 1995), but gentisate 1,2-dioxygenase was induced. Similarly, we found that the Comamonas testosteroni strain CNB-1 degraded benzoate via a CoA-dependent epoxide pathway and that gentisate 1,2-dioxygenase (GenA) was also induced when benzoate or 3-hydroxybenzoate served as a carbon source for growth. Genes encoding the CoA-dependent epoxide (box genes) and gentisate (gen genes) pathways were identified. Genetic disruption revealed that the gen genes were not involved in benzoate and 3-hydroxybenzoate degradation. Hence, we investigated gen gene regulation in the CNB-1 strain. The PgenA promoter, a MarR-type regulator (GenR), and the GenR binding site were identified. We found that GenR took gentisate, 3-hydroxybenzoate, and benzoyl-CoA as effectors and that binding of GenR to its target DNA sequence was prohibited when these effectors were present. In vivo studies showed that the CNB-1 mutant that lost benzoyl-CoA synthesis was not able to activate PgenA promoter, while transcription of genA was upregulated in another CNB-1 mutant that lost the ability to degrade benzoyl-CoA. The finding that benzoyl-CoA (a metabolic intermediate of benzoate degradation) and 3-hydroxybenzoate function as GenR effectors explains why GenA was induced when CNB-1 grew on benzoate or 3-hydroxybenzoate. Regulation of gentisate pathways by MarR-, LysR-, and IclR-type regulators in diverse bacterial groups is discussed in detail. PMID:24771026

Photoaffinity labeling of the TF1-ATPase from the thermophilic bacterium PS3 with 3'-O-(4-benzoyl)benzoyl ADP.

PubMed

Bar-Zvi, D; Yoshida, M; Shavit, N

1985-05-31

3'-O-(4-Benzoyl)benzoyl ADP (BzADP) was used as a photoaffinity label for covalent binding of adenine nucleotide analogs to the nucleotide binding site(s) of the thermophilic bacterium PS3 ATPase (TF1). As with the CF1-ATPase (Bar-Zvi, D. and Shavit, N. (1984) Biochim. Biophys. Acta 765, 340-356) noncovalently bound BzADP is a reversible inhibitor of the TF1-ATPase. BzADP changes the kinetics of ATP hydrolysis from noncooperative to cooperative in the same way as ADP does, but, in contrast to the effect on the CF1-ATPase, it has no effect on the Vmax. In the absence of Mg2+ 1 mol BzADP binds noncovalently to TF1, while with Mg2+ 3 mol are bound. Photoactivation of BzADP results in the covalent binding of the analog to the nucleotide binding site(s) on TF1 and correlates with the inactivation of the ATPase. Complete inactivation of the TF1-ATPase occurs after covalent binding of 2 mol BzADP/mol TF1. Photoinactivation of TF1 by BzADP is prevented if excess of either ADP or ATP is present during irradiation. Analysis by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate of the Bz[3H]ADP-labeled TF1-ATPase shows that all the radioactivity is incorporated into the beta subunit.

40 CFR 721.10166 - 1,3-Cyclohexanedione, 2-[2-chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1). 721.10166 Section 721...(1-), potassium salt (1:1). (a) Chemical substance and significant new uses subject to reporting. (1...-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1) (PMN P-08-180; CAS No. 1121649-70-4) is subject to...

40 CFR 721.10166 - 1,3-Cyclohexanedione, 2-[2-chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl...

Code of Federal Regulations, 2014 CFR

2014-07-01

...-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1). 721.10166 Section 721...(1-), potassium salt (1:1). (a) Chemical substance and significant new uses subject to reporting. (1...-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1) (PMN P-08-180; CAS No. 1121649-70-4) is subject to...

40 CFR 721.10166 - 1,3-Cyclohexanedione, 2-[2-chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl...

Code of Federal Regulations, 2013 CFR

2013-07-01

...-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1). 721.10166 Section 721...(1-), potassium salt (1:1). (a) Chemical substance and significant new uses subject to reporting. (1...-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1) (PMN P-08-180; CAS No. 1121649-70-4) is subject to...

40 CFR 721.10166 - 1,3-Cyclohexanedione, 2-[2-chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl...

Code of Federal Regulations, 2012 CFR

2012-07-01

...-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1). 721.10166 Section 721...(1-), potassium salt (1:1). (a) Chemical substance and significant new uses subject to reporting. (1...-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1) (PMN P-08-180; CAS No. 1121649-70-4) is subject to...

40 CFR 721.10166 - 1,3-Cyclohexanedione, 2-[2-chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1). 721.10166 Section 721...(1-), potassium salt (1:1). (a) Chemical substance and significant new uses subject to reporting. (1...-trifluoroethoxy)methyl]benzoyl]-, ion(1-), potassium salt (1:1) (PMN P-08-180; CAS No. 1121649-70-4) is subject to...

Evaluating clinical trial design: systematic review of randomized vehicle-controlled trials for determining efficacy of benzoyl peroxide topical therapy for acne.

PubMed

Lamel, Sonia A; Sivamani, Raja K; Rahvar, Maral; Maibach, Howard I

2015-11-01

Determined efficacies of benzoyl peroxide may be affected by study design, implementation, and vehicle effects. We sought to elucidate areas that may allow improvement in determining accurate treatment efficacies by determining rates of active treatment and vehicle responders in randomized controlled trials assessing the efficacy of topical benzoyl peroxide to treat acne. We conducted a systematic review of randomized vehicle-controlled trials evaluating the efficacy of topical benzoyl peroxide for the treatment of acne. We compared response rates of vehicle treatment arms versus those in benzoyl peroxide arms. Twelve trials met inclusion criteria with 2818 patients receiving benzoyl peroxide monotherapy treatment and 2004 receiving vehicle treatment. The average percent reduction in total number of acne lesions was 44.3 (SD = 9.2) and 27.8 (SD = 21.0) for the active and vehicle treatment groups, respectively. The average reduction in non-inflammatory lesions was 41.5 % (SD = 9.4) in the active treatment group and 27.0 % (SD = 20.9) in the vehicle group. The average percent decrease in inflammatory lesions was 52.1 (SD = 10.4) in the benzoyl peroxide group and 34.7 (SD = 22.7) in the vehicle group. The average percentage of participants achieving success per designated study outcomes was 28.6 (SD = 17.3) and 15.2 (SD = 9.5) in the active treatment and vehicle groups, respectively. Patient responses in randomized controlled trials evaluating topical acne therapies may be affected by clinical trial design, implementation, the biologic effects of vehicles, and natural disease progression. "No treatment" groups may facilitate determination of accurate treatment efficacies.

Hydrogen bonding pattern in N-benzoyl(- DL-)- L-phenylalanines as revealed by solid-state NMR spectroscopy

NASA Astrophysics Data System (ADS)

Potrzebowski, M. J.; Schneider, C.; Tekely, P.

1999-11-01

The nature of the hydrogen bonding pattern has been investigated in N-benzoyl- DL-phenylalanine ( 1) and N-benzoyl- L-phenylalanine ( 2) polymorphes by solid-state NMR spectroscopy. It has been shown that the multiple resonances of carboxyl carbon in 2 are directly connected to different types of hydrogen bonding. The differences in intermolecular distances of carboxyl groups involved in different types of hydrogen bonding have been visualized by the 2D exchange and 1D ODESSA experiments. Potential applications of such a new approach include the exploration of intermolecular distances in hydrogen bonded compounds with singly labeled biomolecules.

Structure-activity relationships among substituted N-benzoyl derivatives of phenylalanine and its analogs in a microbial antitumor prescreen I: Derivatives of o-fluoro-DL-phenylalanine.

PubMed

Otani, T T; Briley, M R

1982-02-01

Twelve derivatives of 0-fluoro-dl-phenylalanine containing fluorine, chlorine, methoxy, and nitro radicals in various positions of the aromatic ring of the benzoyl group were prepared and tested in a Lactobacillus casei system. It was found that most substitutions in the benzoyl phenyl ring resulted in a compound exhibiting greater growth-inhibiting activity than the nonsubstituted benzoyl-o-fluorophenylalanine. The greatest activity was observed in the ortho-substituted fluoro compound and the meta- and para-substituted chloro and nitro compounds. With the methoxy group, the position of substitution appeared unimportant, since all three methoxy isomers exhibited essentially equal inhibition. Nitro substitution in the ortho position had a protective effect in that the product was less active than the unsubstituted benzoyl-o-fluoro-dl-phenylalanine.

Sensory and Functionality Differences of Whey Protein Isolate Bleached by Hydrogen or Benzoyl Peroxide.

PubMed

Smith, Tucker J; Foegeding, E Allen; Drake, MaryAnne

2015-10-01

Whey protein is a highly functional food ingredient used in a wide variety of applications. A large portion of fluid whey produced in the United States is derived from Cheddar cheese manufacture and contains annatto (norbixin), and therefore must be bleached. The objective of this study was to compare sensory and functionality differences between whey protein isolate (WPI) bleached by benzoyl peroxide (BP) or hydrogen peroxide (HP). HP and BP bleached WPI and unbleached controls were manufactured in triplicate. Descriptive sensory analysis and gas chromatography-mass spectrometry were conducted to determine flavor differences between treatments. Functionality differences were evaluated by measurement of foam stability, protein solubility, SDS-PAGE, and effect of NaCl concentration on gelation relative to an unbleached control. HP bleached WPI had higher concentrations of lipid oxidation and sulfur containing volatile compounds than both BP and unbleached WPI (P < 0.05). HP bleached WPI was characterized by high aroma intensity, cardboard, cabbage, and fatty flavors, while BP bleached WPI was differentiated by low bitter taste. Overrun and yield stress were not different among WPI (P < 0.05). Soluble protein loss at pH 4.6 of WPI decreased by bleaching with either hydrogen peroxide or benzoyl peroxide (P < 0.05), and the heat stability of WPI was also distinct among WPI (P < 0.05). SDS PAGE results suggested that bleaching of whey with either BP or HP resulted in protein degradation, which likely contributed to functionality differences. These results demonstrate that bleaching has flavor effects as well as effects on many of the functionality characteristics of whey proteins. Whey protein isolate (WPI) is often used for its functional properties, but the effect of oxidative bleaching chemicals on the functional properties of WPI is not known. This study identifies the effects of hydrogen peroxide and benzoyl peroxide on functional and flavor characteristics of WPI

Copper-Catalyzed Electrophilic Amination of Organoaluminum Nucleophiles with O-Benzoyl Hydroxylamines.

PubMed

Zhou, Shuangliu; Yang, Zhiyong; Chen, Xu; Li, Yimei; Zhang, Lijun; Fang, Hong; Wang, Wei; Zhu, Xiancui; Wang, Shaowu

2015-06-19

A copper-catalyzed electrophilic amination of aryl and heteroaryl aluminums with N,N-dialkyl-O-benzoyl hydroxylamines that affords the corresponding anilines in good yields has been developed. The catalytic reaction proceeds very smoothly under mild conditions and exhibits good substrate scope. Moreover, the developed catalytic system is also well suited for heteroaryl aluminum nucleophiles, providing facile access to heteroaryl amines.

Phototoxic effects of topical azelaic acid, benzoyl peroxide and adapalene were not detected when applied immediately before UVB to normal skin.

PubMed

Cetiner, Salih; Ilknur, Turna; Ozkan, Sebnem

2004-01-01

The enhancing effects on UVB erythema of topical agents applied on sun exposed areas are important due to their increased sunburn risk. Since the lesions in acne vulgaris are seen primarily on the face, the effects of topical agents used in acne treatment on the erythemogenicity of UVB is important. The aim of the present study was to examine whether azelaic acid cream, benzoyl peroxide gel, adapalene gel have the enhancing effects on UVB erythema which are widely used in the topical treatment of acne vulgaris. The minimal erythema dose (MED) was determined with phototest in 30 volunteers and the test was repeated with thin (0.1 cc/25 cm(2)) and thick (0.3 cc/25 cm(2)) azelaic acid cream, benzoyl peroxide gel, adapalene gel. The effects of each agent on MED was determined after 24 hours. MEDs of UVB were unaffected by azelaic acid cream, benzoyl peroxide gel and adapalene gel when applied immediately before irradiation. According to our results azelaic acid, benzoyl peroxide and adapalene do not seem to have enhancing effects on UVB erythema and thus increased sunburn risk.

Copper(II)-catalyzed electrophilic amination of quinoline N-oxides with O-benzoyl hydroxylamines.

PubMed

Li, Gang; Jia, Chunqi; Sun, Kai; Lv, Yunhe; Zhao, Feng; Zhou, Kexiao; Wu, Hankui

2015-03-21

Copper acetate-catalyzed C-H bond functionalization amination of quinoline N-oxides was achieved using O-benzoyl hydroxylamine as an electrophilic amination reagent, thereby affording the desired products in moderate to excellent yields. Electrophilic amination can also be performed in good yield on a gram scale.

Randomized, Observer-blind, Split-face Compatibility Study with Clindamycin Phosphate 1.2%/Benzoyl Peroxide 3.75% gel and Facial Foundation Makeup.

PubMed

Bhatia, Neal; Pillai, Radhakrishnan

2015-09-01

Cosmetic compatibility in the treatment of acne is an important issue significantly impacting quality of life, but often overlooked, as dermatologists commonly recommended avoidance of cosmetic foundations when treating adult female patients. Fixed combinations of clindamycin/benzoyl peroxide are widely used in the treatment of acne, but little is known about the impact of their concomitant use with facial foundation. To assess the compatibility of clindamycin phosphate 1. 2%/benzoyl peroxide 3. 75% gel with foundation makeup for up to six hours after application. Twenty-nine female subjects applied makeup to their face after randomly applying clindamycin phosphate 1. 2%/benzoyl peroxide 3. 75% gel to one side of the face. Investigator and subject self- assessment included facial skin attributes, facial tolerability, and cosmetic compatibility post-application and at Hour 6; as well as cutaneous tolerability. No statistical difference was noted between the treated and untreated side of the face in terms of coverage, blotchiness, appearance, skin tone, or visual smoothness. Tolerability was excellent, with no erythema, edema, dryness, and peeling post-makeup application. For both the treated and untreated side, there was a slight lack of improvement in cosmetic appearance six hours post-makeup application. Clindamycin/benzoyl peroxide 3. 75% gel was shown to have excellent cosmetic compatibility with facial foundation.

Randomized, Observer-blind, Split-face Compatibility Study with Clindamycin Phosphate 1.2%/Benzoyl Peroxide 3.75% gel and Facial Foundation Makeup

PubMed Central

Pillai, Radhakrishnan

2015-01-01

Background: Cosmetic compatibility in the treatment of acne is an important issue significantly impacting quality of life, but often overlooked, as dermatologists commonly recommended avoidance of cosmetic foundations when treating adult female patients. Fixed combinations of clindamycin/benzoyl peroxide are widely used in the treatment of acne, but little is known about the impact of their concomitant use with facial foundation. Objective: To assess the compatibility of clindamycin phosphate 1. 2%/benzoyl peroxide 3. 75% gel with foundation makeup for up to six hours after application. Methods: Twenty-nine female subjects applied makeup to their face after randomly applying clindamycin phosphate 1. 2%/benzoyl peroxide 3. 75% gel to one side of the face. Investigator and subject self- assessment included facial skin attributes, facial tolerability, and cosmetic compatibility post-application and at Hour 6; as well as cutaneous tolerability. Results: No statistical difference was noted between the treated and untreated side of the face in terms of coverage, blotchiness, appearance, skin tone, or visual smoothness. Tolerability was excellent, with no erythema, edema, dryness, and peeling post-makeup application. For both the treated and untreated side, there was a slight lack of improvement in cosmetic appearance six hours post-makeup application. Conclusion: Clindamycin/benzoyl peroxide 3. 75% gel was shown to have excellent cosmetic compatibility with facial foundation. PMID:26430488

Breaking Benzene Aromaticity-Computational Insights into the Mechanism of the Tungsten-Containing Benzoyl-CoA Reductase.

PubMed

Culka, Martin; Huwiler, Simona G; Boll, Matthias; Ullmann, G Matthias

2017-10-18

Aromatic compounds are environmental pollutants with toxic and carcinogenic properties. Despite the stability of aromatic rings, bacteria are able to degrade the aromatic compounds into simple metabolites and use them as growth substrates under oxic or even under anoxic conditions. In anaerobic microorganisms, most monocyclic aromatic growth substrates are converted to the central intermediate benzoyl-coenzyme A, which is enzymatically reduced to cyclohexa-1,5-dienoyl-CoA. The strictly anaerobic bacterium Geobacter metallireducens uses the class II benzoyl-CoA reductase complex for this reaction. The catalytic BamB subunit of this complex harbors an active site tungsten-bis-pyranopterin cofactor with the metal being coordinated by five protein/cofactor-derived sulfur atoms and a sixth, so far unknown, ligand. Although BamB has been biochemically and structurally characterized, its mechanism still remains elusive. Here we use continuum electrostatic and QM/MM calculations to model benzoyl-CoA reduction by BamB. We aim to elucidate the identity of the sixth ligand of the active-site tungsten ion together with the interplay of the electron and proton transfer events during the aromatic ring reduction. On the basis of our calculations, we propose that benzoyl-CoA reduction is initiated by a hydrogen atom transfer from a W(IV) species with an aqua ligand, yielding W(V)-[OH - ] and a substrate radical intermediate. In the next step, a proton-assisted second electron transfer takes place with a conserved active-site histidine serving as the second proton donor. Interestingly, our calculations suggest that the electron for the second reduction step is taken from the pyranopterin cofactors rather than from the tungsten ion. The resulting cationic radical, which is distributed over both pyranopterins, is stabilized by conserved anionic amino acid residues. The stepwise mechanism of the reduction shows similarities to the Birch reduction known from organic chemistry. However

Anaerobic degradation of 2-aminobenzoic acid (anthranilic acid) via benzoyl-coenzyme A (CoA) and cyclohex-1-enecarboxyl-CoA in a denitrifying bacterium.

PubMed Central

Lochmeyer, C; Koch, J; Fuchs, G

1992-01-01

The enzymes catalyzing the initial reactions in the anaerobic degradation of 2-aminobenzoic acid (anthranilic acid) were studied with a denitrifying Pseudomonas sp. anaerobically grown with 2-aminobenzoate and nitrate as the sole carbon and energy sources. Cells grown on 2-aminobenzoate are simultaneously adapted to growth with benzoate, whereas cells grown on benzoate degrade 2-aminobenzoate several times less efficiently than benzoate. Evidence for a new reductive pathway of aromatic metabolism and for four enzymes catalyzing the initial steps is presented. The organism contains 2-aminobenzoate-coenzyme A ligase (2-aminobenzoate-CoA ligase), which forms 2-aminobenzoyl-CoA. 2-Aminobenzoyl-CoA is then reductively deaminated to benzoyl-CoA by an oxygen-sensitive enzyme, 2-aminobenzoyl-CoA reductase (deaminating), which requires a low potential reductant [Ti(III)]. The specific activity is 15 nmol of 2-aminobenzoyl-CoA reduced min-1 mg-1 of protein at an optimal pH of 7. The two enzymes are induced by the substrate under anaerobic conditions only. Benzoyl-CoA is further converted in vitro by reduction with Ti(III) to six products; the same products are formed when benzoyl-CoA or 2-aminobenzoyl-CoA is incubated under reducing conditions. Two of them were identified preliminarily. One product is cyclohex-1-enecarboxyl-CoA, the other is trans-2-hydroxycyclohexane-carboxyl-CoA. The complex transformation of benzoyl-CoA is ascribed to at least two enzymes, benzoyl-CoA reductase (aromatic ring reducing) and cyclohex-1-enecarboxyl-CoA hydratase. The reduction of benzoyl-CoA to alicyclic compounds is catalyzed by extracts from cells grown anaerobically on either 2-aminobenzoate or benzoate at almost the same rate (10 to 15 nmol min-1 mg-1 of protein). In contrast, extracts from cells grown anaerobically on acetate or grown aerobically on benzoate or 2-aminobenzoate are inactive. This suggests a sequential induction of the enzymes. Images PMID:1592816

Anaerobic degradation of 2-aminobenzoic acid (anthranilic acid) via benzoyl-coenzyme A (CoA) and cyclohex-1-enecarboxyl-CoA in a denitrifying bacterium.

PubMed

Lochmeyer, C; Koch, J; Fuchs, G

1992-06-01

The enzymes catalyzing the initial reactions in the anaerobic degradation of 2-aminobenzoic acid (anthranilic acid) were studied with a denitrifying Pseudomonas sp. anaerobically grown with 2-aminobenzoate and nitrate as the sole carbon and energy sources. Cells grown on 2-aminobenzoate are simultaneously adapted to growth with benzoate, whereas cells grown on benzoate degrade 2-aminobenzoate several times less efficiently than benzoate. Evidence for a new reductive pathway of aromatic metabolism and for four enzymes catalyzing the initial steps is presented. The organism contains 2-aminobenzoate-coenzyme A ligase (2-aminobenzoate-CoA ligase), which forms 2-aminobenzoyl-CoA. 2-Aminobenzoyl-CoA is then reductively deaminated to benzoyl-CoA by an oxygen-sensitive enzyme, 2-aminobenzoyl-CoA reductase (deaminating), which requires a low potential reductant [Ti(III)]. The specific activity is 15 nmol of 2-aminobenzoyl-CoA reduced min-1 mg-1 of protein at an optimal pH of 7. The two enzymes are induced by the substrate under anaerobic conditions only. Benzoyl-CoA is further converted in vitro by reduction with Ti(III) to six products; the same products are formed when benzoyl-CoA or 2-aminobenzoyl-CoA is incubated under reducing conditions. Two of them were identified preliminarily. One product is cyclohex-1-enecarboxyl-CoA, the other is trans-2-hydroxycyclohexane-carboxyl-CoA. The complex transformation of benzoyl-CoA is ascribed to at least two enzymes, benzoyl-CoA reductase (aromatic ring reducing) and cyclohex-1-enecarboxyl-CoA hydratase. The reduction of benzoyl-CoA to alicyclic compounds is catalyzed by extracts from cells grown anaerobically on either 2-aminobenzoate or benzoate at almost the same rate (10 to 15 nmol min-1 mg-1 of protein). In contrast, extracts from cells grown anaerobically on acetate or grown aerobically on benzoate or 2-aminobenzoate are inactive. This suggests a sequential induction of the enzymes.

Structure-activity relationships among substituted N-benzoyl derivatives of phenylalanine and its analogues in a microbial antitumor prescreen III: derivatives of p-fluoro-DL-phenylalanine.

PubMed

Otani, T T; Briley, M R

1985-01-01

Twelve substituted benzoyl derivatives of p-fluoro-DL-phenylalanine were prepared and tested for growth-inhibitory activity in a Lactobacillus casei system used as an antitumor prescreen. The 12 substituted benzoyl groups were the same as those attached to o-fluorophenylalanine and m-fluorophenylalanine studied earlier. The activity of these compounds was compared vertically among themselves and horizontally with the corresponding derivatives of o-fluorophenylalanine and of m-fluorophenylalanine. It was found that the derivatives of p-fluorophenylalanine, like those of o- and m-fluorophenylalanine, exhibited remarkable inhibition, all but one, i.e., the o-nitrobenzoyl derivative, showing inhibition that is considered to be positive in the prescreen. Particularly potent compounds in this group were the m-chlorobenzoyl-, p-chlorobenzoyl, m-nitrobenzoyl, and p-nitrobenzoyl derivatives. Comparison of the activity of the substituted benzoyl derivatives of all three structural isomers of fluorophenylalanine at equimolar concentrations showed that the derivatives of m-fluorophenylalanine were generally better inhibitors than those of o-fluoro- or p-fluorophenylalanine. Study of the ID50 values of the more active substituted benzoyl derivatives of the fluorophenylalanines showed that the most active of this group was m-chlorobenzoyl-p-fluoro-DL-phenylalanine.

The study of structure-activity relationships among substituted N-benzoyl derivatives of phenylalanine and its analogs in a microbial antitumor prescreen: II. Derivatives of m-fluoro-DL-phenylalanine.

PubMed

Otani, T T; Briley, M R

1983-05-01

The fluoro-, chloro-, methoxy- and nitro-substituted benzoyl derivatives of m-fluoro-DL-phenylalanine, substituted singly at the ortho, meta or para position of the benzoyl phenyl ring, were prepared and tested for growth-inhibitory activity in a Lactobacillus casei system used as an antitumor prescreen. The substituted benzoyl derivatives that were previously found to be the most active for o-fluoro-DL-phenylalanine were also the most active for the m-fluoro-DL-phenylalanine. The position of the fluorine substituent in the phenylalanine also appeared to be important for inhibitory activity as the derivatives of m-fluoro-phenylalanine were in general better inhibitors than those of the corresponding o-fluorophenylalanine.

5-Benzoyl-13-bromo-4-hy­droxy[2.2]paracyclo­phane

PubMed Central

Ma, Kelin; Duan, Wenzeng; He, Fuyan; Ma, Yudao

2012-01-01

The title compound, C23H19BrO2, was synthesized from 13-bromo-4-hy­droxy[2.2]paracyclo­phane and benzoyl chloride. The hy­droxy and carbonyl groups are involved in intra­molecular O—H⋯O hydrogen bonding. The crystal packing exhibits weak C—H⋯O inter­actions, which link the mol­ecules into sheets parallel to the bc plane. PMID:22590271

Structural, antimicrobial and computational characterization of 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea.

PubMed

Atiş, Murat; Karipcin, Fatma; Sarıboğa, Bahtiyar; Taş, Murat; Çelik, Hasan

2012-12-01

A new thiourea derivative, 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea (bcht) has been synthesized from the reaction of 2-amino-4-chlorophenol with benzoyl isothiocyanate. The title compound has been characterized by elemental analyses, FT-IR, (13)C, (1)H NMR spectroscopy and the single crystal X-ray diffraction analysis. The structure of bcht derived from X-ray diffraction of a single crystal has been presented. The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional method using 6-311++G(d,p) basis set. The complete assignments of all vibrational modes were performed on the basis of the total energy distributions (TED). Isotropic chemical shifts ((13)C NMR and (1)H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. Theoretical calculations of bond parameters, harmonic vibration frequencies and nuclear magnetic resonance are in good agreement with experimental results. The UV absorption spectra of the compound that dissolved in ACN and MeOH were recorded. Bcht was also screened for antimicrobial activity against pathogenic bacteria and fungi. Copyright © 2012 Elsevier B.V. All rights reserved.

Quantitative detection of benzoyl peroxide in wheat flour by line-scan macro-scale Raman chemical imaging

USDA-ARS?s Scientific Manuscript database

A high-throughput Raman chemical imaging method was developed for direct inspection of benzoyl peroxide (BPO) mixed in wheat flour. A 5 W 785 nm line laser (240 mm long and 1 mm wide) was used as a Raman excitation source in a push-broom Raman imaging system. Hyperspectral Raman images were collecte...

Sub-group Analyses from a Trial of a Fixed Combination of Clindamycin Phosphate 1.2% and Benzoyl Peroxide 3.75% Gel for the Treatment of Moderate-to-severe Acne Vulgaris

PubMed Central

Korotzer, Andrew

2015-01-01

Background: Acne vulgaris is commonplace and can be difficult to manage. Providing an effective and well-tolerated treatment may lead to improved adherence, increased patient satisfaction, and improved clinical outcomes. Methods: A review of efficacy, safety, and cutaneous tolerability of clindamycin phosphate 1.2%-benzoyl peroxide 3.75% gel in 498 patients with moderate-to-severe acne vulgaris enrolled in a multicenter Phase III study randomized to receive active or vehicle once daily for 12 weeks, including the most recent post-hoc analyses. Results: Significantly superior reductions in lesion counts were observed with clindamycin phosphate 1.2%-benzoyl peroxide 3.75% gel from Week 4, with median percent reductions in inflammatory and noninflammatory lesions from baseline of 68.4 and 57.9 percent, respectively (bothp<0.001 versus vehicle). More than half (55.1%) of the severe acne vulgaris patients treated with clindamycin phosphate 1.2%-benzoyl peroxide 3.75% gel achieved ≥2-grade improvement from baseline in their Evaluator’s Global Severity Score, and almost a third of the adolescent acne vulgaris patients (32.4%) achieved at least a marked improvement in their acne vulgaris as early as Week 2. In adult female acne overall treatments success was achieved in 52.7 percent of patients treated with clindamycin phosphate 1.2%-benzoyl peroxide 3.75% gel. Overall, and in the specific subpopulations, clindamycin phosphate 1.2%-benzoyl peroxide 3.75% gel was well-tolerated with a similar adverse event profile to vehicle. Limitations: Post-hoc analyses from a single clinical trial with demographic imbalances that could potentially confound the results. Conclusion: Clindamycin phosphate 1.2%-benzoyl peroxide 3.75% gel appears to be effective in treating acne across various clinically relevant sub-groups. PMID:26705445

Discriminative Dissolution Method for Benzoyl Metronidazole Oral Suspension.

PubMed

da Silva, Aline Santos; da Rosa Silva, Carlos Eduardo; Paula, Fávero Reisdorfer; da Silva, Fabiana Ernestina Barcellos

2016-06-01

A dissolution method for benzoyl metronidazole (BMZ) oral suspensions was developed and validated using a high-performance liquid chromatography (HPLC) method. After determination of sink conditions, dissolution profiles were evaluated using different dissolution media and agitation speeds. The sample insertion mode in dissolution media was also evaluated. The best conditions were obtained using a paddle, 50 rpm stirring speed, simulated gastric fluid (without pepsin) as the dissolution medium, and sample insertion by a syringe. These conditions were suitable for providing sink conditions and discriminatory power between different formulations. Through the tested conditions, the results can be considered specific, linear, precise, accurate, and robust. The dissolution profiles of five samples were compared using the similarity factor (f 2) and dissolution efficiency. The dissolution kinetics were evaluated and described by the Weibull model. Whereas there is no monograph for this pharmaceutical formulation, the dissolution method proposed can be considered suitable for quality control and dissolution profile comparison of different commercial formulations.

Comparison of a chlorhexidine and a benzoyl peroxide shampoo as sole treatment in canine superficial pyoderma.

PubMed

Loeffler, A; Cobb, M A; Bond, R

2011-09-03

The clinical and antibacterial efficacy of two shampoos used as a sole antibacterial treatment in dogs with superficial pyoderma were investigated and compared. In a randomised, partially blinded study, a 3 per cent chlorhexidine gluconate shampoo (Chlorhex 3; Leo Animal Health) was compared against a 2.5 per cent benzoyl peroxide shampoo (Paxcutol; Virbac) in 22 dogs with superficial pyoderma. Dogs were washed two to three times weekly with a 10-minute contact time over 21 days. Clinical scores and bacterial counts were assessed on days 1, 8 and 22 and compared within and between treatment groups; overall response was assessed at the end of the study. Twenty dogs completed the study; 15 (68.2 per cent) showed an overall clinical improvement and the clinical signs resolved in three chlorhexidine-treated dogs. In the chlorhexidine-treated group, scores for papules/pustules (P<0.001), investigator-assessed pruritus (P=0.003), total bacterial counts (P=0.003) and counts for coagulase-positive staphylococci (P=0.003) were reduced after three weeks. Scores and bacterial counts did not vary significantly in the benzoyl peroxide-treated group.

N-benzoylated 1,4,8,11-tetraazacyclotetradecane and their copper(II) and nickel(II) complexes: Spectral, magnetic, electrochemical, crystal structure, catalytic and antimicrobial studies

NASA Astrophysics Data System (ADS)

Nirmala, G.; Rahiman, A. Kalilur; Sreedaran, S.; Jegadeesh, R.; Raaman, N.; Narayanan, V.

2010-09-01

A series of N-benzoylated cyclam ligands incorporating three different benzoyl groups 1,4,8,11-tetra-(benzoyl)-1,4,8,11-tetraazacyclotetradecane (L 1), 1,4,8,11-tetra-(2-nitrobenzoyl)-1,4,8,11-tetraazacyclotetradecane (L 2) and 1,4,8,11-tetra-(4-nitrobenzoyl)-1,4,8,11-tetraazacyclotetradecane (L 3) and their nickel(II) and copper(II) complexes are described. Crystal structure of L 1 is also reported. The ligands and complexes were characterized by elemental analysis, electronic, IR, 1H NMR and 13C NMR spectral studies. N-benzoylation causes red shift in the λmax values of the complexes. The cyclic voltammogram of the complexes of ligand L 1 show one-electron, quasi-reversible reduction wave in the region -1.00 to -1.04 V, whereas that of L 2 and L 3 show two quasi-reversible reduction peaks. Nickel complexes show one-electron quasi-reversible oxidation wave at a positive potential in the range +1.05 to +1.15 V. The ESR spectra of the mononuclear copper(II) complexes show four lines, characteristic of square-planar geometry with nuclear hyperfine spin 3/2. All copper(II) complexes show a normal room temperature magnetic moment values μeff 1.70-1.73 BM which is close to the spin-only value of 1.73 BM. Kinetic studies on the oxidation of pyrocatechol to o-quinone using the copper(II) complexes as catalysts and hydrolysis of 4-nitrophenylphosphate using the copper(II) and nickel(II) complexes as catalysts were carried out. All the ligands and their complexes were also screened for antimicrobial activity against Gram-positive, Gram-negative bacteria and human pathogenic fungi.

Results of a Multicenter, Randomized, Controlled Trial of a Hydrogen Peroxide-based Kit versus a Benzoyl Peroxide-based Kit in Mild-to-moderate Acne

PubMed Central

Micali, Giuseppe; Berardesca, Enzo; Dall’Oglio, Federica; Sinagra, Jo Linda; Guanziroli, Elena

2016-01-01

Objective:To evaluate the efficacy and tolerability of a novel hydrogen peroxide-based regimen versus a benzoyl peroxide-based regimen in mild-to-moderate acne. Methods: In this eight-week multicenter study, patients were randomized to either a hydrogen peroxide-based or a benzoyl peroxide-based regimen.The primary outcome measure of clinical response was assessed using the Global Acne Grading System (GAGS) at baseline,four weeks, and eight weeks. At Week 8, a patient self-satisfaction questionnaire was administered. Investigators were also queried at that time regarding assessment of tolerability and cosmetic acceptability. Tolerability was also measured at each visit. Results: Both treatment regimens were associated with improvement of GAGS score at Week 8 compared to baseline (p<0.0001). GAGS score did not differ significantly between the two regimens over the same period (p=0.7765). No significant adverse events were reported or observed in either treatment arm. Both patients and investigators found both regimens to be similarly effective and cosmetically acceptable. Conclusion: A novel hydrogen peroxide-based regimen was shown to be comparable in efficacy, safety, and cosmetic acceptability to a benzoyl peroxide-based regimen in the treatment of mild-to-moderate acne. PMID:27847549

Antimicrobial activity of 9-O-acyl- and 9-O-benzoyl-substituted berberrubines.

PubMed

Hong, S W; Kim, S H; Jeun, J A; Lee, S J; Kim, S U; Kim, J H

2000-05-01

In the course of a structure-activity relationship study on berberrubine derivatives, a series of compounds bearing 9-O-acyl-(4-6) and 9-O-benzoyl- (7) substituents was synthesized with the expectation of increasing the antimicrobial activity. One of the berberrubine derivatives, 9-lauroylberberrubine chloride was the most active against Gram-positive bacteria Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Bacillus subtilis as well as the Gram-negative bacterium Klebsiella pneumoniae in comparison to berberine, the currently used antibiotic in clinic. This result suggested that the presence of lipophilic substituents of certain structures and sizes might be crucial for the optimal antimicrobial activity.

Crystal structure of 2-benzoyl­amino-N′-(4-hy­droxy­benzyl­idene)-3-(thio­phen-2-yl)prop-2-eno­hydrazide

PubMed Central

Subbulakshmi, Karanth N.; Narayana, Badiadka; Yathirajan, Hemmige S.; Jasinski, Jerry P.; Rathore, Ravindranath S.; Glidewell, Christopher

2016-01-01

In the title compound, C21H17N3O3S, the non-H atoms, apart from those in the benzoyl group, are almost coplanar (r.m.s. deviation = 0.049 Å) and the benzoyl group is almost orthogonal to the plane of the rest of the mol­ecule [dihedral angle = 80.34 (6)°]. In the crystal, a combination of N—H⋯O and asymmetric bifurcated O—H⋯(N,O) hydrogen bonds link the mol­ecules into a three-dimensional network. Weak C—H⋯O inter­actions are also observed. PMID:27536390

[Acne therapy with topical benzoyl peroxide, antibiotics and azelaic acid].

PubMed

Worret, Wolf-Ingo; Fluhr, Joachim W

2006-04-01

Benzoyl peroxide (BPO) was introduced in the treatment of acne in 1934. Despite the fact that only few randomized trials have been published, BPO is considered the standard in topical acne treatment. Anaerobic bacteria are reduced by oxidative mechanisms and the induction of resistant strains is reduced. Topical formulations are available at concentrations of 2.5, 5, 10 and 20 %. The effect is dose-dependent, but the irritation increases with higher concentrations. Usually 5 % BPO is sufficient to control acne grade I-II. Due to its strong oxidative potential, patients should be advised that BPO may bleach colored and dark clothing, bedding and even hair. BPO is safe for use in pregnant and lactating females because it is degraded to benzoic acid. It is a cost-effective treatment for acne grade I-II. Patients with papulopustular acne grade I-II, particularly with marked inflammation, show satisfactory improvement with topical antibiotic treatment. The following compounds are available and effective: erythromycin, clindamycin and tetracycline (the latter being less frequently used). A review in 1990 suggested that topical tetracycline was ineffective in the treatment of acne. Along with eliminating Propionibacterium acnes, the main mechanism of topical antibiotics is their antiinflammatory effect. All three penetrate the epidermal barrier well and are similarly efficacious. Randomized trials have shown that in concentrations of 2-4 %, their effects are comparable to oral tetracycline and minocycline. Combination therapy with retinoids or benzoyl peroxide (BPO) increases efficacy. Retinoids increase penetration and reduce comedones, while topical antibiotics primarily address inflammation. One side effect of topical antibacterial treatment is an increase in drug-resistant resident skin flora with gram-negative microorganisms prevailing, which can lead to gram-negative folliculitis. All three antibiotics fluoresce under black light which may produce interesting

1-(1,3-Benzothia­zol-2-yl)-3-benzoyl­thio­urea

PubMed Central

Yunus, Uzma; Tahir, Muhammad Kalim; Bhatti, Moazzam Hussain; Ali, Saqib; Wong, Wai-Yeung

2008-01-01

The title compound, C15H11N3OS2, was synthesized from benzoyl thio­cyanate and 2-amino­benzothia­zole in dry acetone. The thio­urea group is in the thio­amide form. The mol­ecules are stabilized by two inter­molecular C—H⋯S and C—H⋯O hydrogen bonds. Intra­molecular N—H⋯O hydrogen bonding results in a pseudo-S(6) planar ring with dihedral angles of 11.23 and 11.91° with the benzothiazole ring system and the phenyl ring, respectively. PMID:21200765

N-Benzoyl-D-phenylalanine attenuates brain acetylcholinesterase in neonatal streptozotocin-diabetic rats.

PubMed

Ashokkumar, Natarajan; Pari, Leelavinothan; Ramkumar, Kunga Mohan

2006-09-01

The effect of hyperglycaemia due to experimental diabetes in male Wistar rats causes a decrease in the level of acetylcholinesterase (AChE) with significant increase in lipid peroxidative markers: thiobarbituric acid-reactive substances (TBARS) and hydroperoxides in brains of experimental animals. The decreased activity of both salt soluble and detergent soluble acetylcholinesterase observed in diabetes may be attributed to lack of insulin which causes specific alterations in the level of neurotransmitter, thus causing brain dysfunction. Administration of non-sulfonylurea drug N-benzoyl-D-phenylalanine (NBDP) could protect against direct action of lipid peroxidation on brain AChE and in this way it might be useful in the prevention of cholinergic neural dysfunction, which is one of the major complications in diabetes.

Benzoyl radicals from (hetero)aromatic aldehydes. Decatungstate photocatalyzed synthesis of substituted aromatic ketones.

PubMed

Ravelli, Davide; Zema, Michele; Mella, Mariella; Fagnoni, Maurizio; Albini, Angelo

2010-09-21

Benzoyl radicals are generated directly from (hetero)aromatic aldehydes upon tetrabutylammonium decatungstate ((n-Bu(4)N)(4)W(10)O(32)), TBADT) photocatalysis under mild conditions. In the presence of alpha,beta-unsaturated esters, ketones and nitriles radical conjugate addition ensues and gives the corresponding beta-functionalized aryl alkyl ketones in moderate to good yields (stereoselectively in the case of 3-methylene-2-norbornanone). Due to the mild reaction conditions the presence of various functional groups on the aromatic ring is tolerated (e.g. methyl, methoxy, chloro). The method can be applied to hetero-aromatic aldehydes whether electron-rich (e.g. thiophene-2-carbaldehyde) or electron-poor (e.g. pyridine-3-carbaldehyde).

Benzoyl peroxide and clindamycin topical skin preparation decreases Propionibacterium acnes colonization in shoulder arthroscopy.

PubMed

Dizay, Hailey H; Lau, Diana G; Nottage, Wesley M

2017-07-01

Propionibacterium acnes is a gram-positive anaerobe that can lead to devastating postoperative shoulder infections. The objective of this study was to investigate whether a benzoyl peroxide and clindamycin preoperative skin preparation reduces the incidence of P. acnes colonization during shoulder arthroscopy. Sixty-five shoulder arthroscopy patients were prospectively enrolled. A skin culture specimen was taken at the preoperative visit from standard arthroscopic portal sites. Topical benzoyl peroxide 5% and clindamycin 1.2% (BPO/C) gel was applied to the shoulder every night before surgery. Skin culture was repeated in the operating room before preparation with chlorhexidine gluconate. Shoulder arthroscopy proceeded, with final culture specimens obtained from within the shoulder. P. acnes skin colonization remained similar to prior studies at 47.7% (31 of 65 patients.) With >1 application, BPO/C was 78.9% (15 of 19 patients) effective in eliminating P. acnes superficial colonization. With 1 application, it was 66.7% (8 of 12 patients) effective in eliminating superficial colonization. Deep colonization was reduced to 3.1% (2 of 65 patients) compared with previous studies of 15% to 20% (P = .006). BPO/C was 100% effective at decreasing deep colonization with >1 application. P. acnes skin colonization is high at arthroscopic shoulder portals, especially in men. Despite standard skin preparation and prophylactic antibiotics, the rate of joint inoculation is much higher than the rate of infection reported in the literature. BPO/C effectively reduces P. acnes colonization in shoulder arthroscopy. It should be considered for use before shoulder procedures with a time-related trend of >1 application. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Structure and Function of the Unusual Tungsten Enzymes Acetylene Hydratase and Class II Benzoyl-Coenzyme A Reductase.

PubMed

Boll, Matthias; Einsle, Oliver; Ermler, Ulrich; Kroneck, Peter M H; Ullmann, G Matthias

2016-01-01

In biology, tungsten (W) is exclusively found in microbial enzymes bound to a bis-pyranopterin cofactor (bis-WPT). Previously known W enzymes catalyze redox oxo/hydroxyl transfer reactions by directly coordinating their substrates or products to the metal. They comprise the W-containing formate/formylmethanofuran dehydrogenases belonging to the dimethyl sulfoxide reductase (DMSOR) family and the aldehyde:ferredoxin oxidoreductase (AOR) families, which form a separate enzyme family within the Mo/W enzymes. In the last decade, initial insights into the structure and function of two unprecedented W enzymes were obtained: the acetaldehyde forming acetylene hydratase (ACH) belongs to the DMSOR and the class II benzoyl-coenzyme A (CoA) reductase (BCR) to the AOR family. The latter catalyzes the reductive dearomatization of benzoyl-CoA to a cyclic diene. Both are key enzymes in the degradation of acetylene (ACH) or aromatic compounds (BCR) in strictly anaerobic bacteria. They are unusual in either catalyzing a nonredox reaction (ACH) or a redox reaction without coordinating the substrate or product to the metal (BCR). In organic chemical synthesis, analogous reactions require totally nonphysiological conditions depending on Hg2+ (acetylene hydration) or alkali metals (benzene ring reduction). The structural insights obtained pave the way for biological or biomimetic approaches to basic reactions in organic chemistry. © 2016 S. Karger AG, Basel.

Effect of temperature and concentration on benzoyl peroxide bleaching efficacy and benzoic acid levels in whey protein concentrate.

PubMed

Smith, T J; Gerard, P D; Drake, M A

2015-11-01

Much of the fluid whey produced in the United States is a by-product of Cheddar cheese manufacture and must be bleached. Benzoyl peroxide (BP) is currently 1 of only 2 legal chemical bleaching agents for fluid whey in the United States, but benzoic acid is an unavoidable by-product of BP bleaching. Benzoyl peroxide is typically a powder, but new liquid BP dispersions are available. A greater understanding of the bleaching characteristics of BP is necessary. The objective of the study was to compare norbixin destruction, residual benzoic acid, and flavor differences between liquid whey and 80% whey protein concentrates (WPC80) bleached at different temperatures with 2 different benzoyl peroxides (soluble and insoluble). Two experiments were conducted in this study. For experiment 1, 3 factors (temperature, bleach type, bleach concentration) were evaluated for norbixin destruction using a response surface model-central composite design in liquid whey. For experiment 2, norbixin concentration, residual benzoic acid, and flavor differences were explored in WPC80 from whey bleached by the 2 commercially available BP (soluble and insoluble) at 5 mg/kg. In liquid whey, soluble BP bleached more norbixin than insoluble BP, especially at lower concentrations (5 and 10 mg/kg) at both cold (4°C) and hot (50°C) temperatures. The WPC80 from liquid whey bleached with BP at 50°C had lower norbixin concentration, benzoic acid levels, cardboard flavor, and aldehyde levels than WPC80 from liquid whey bleached with BP at 4°C. Regardless of temperature, soluble BP destroyed more norbixin at lower concentrations than insoluble BP. The WPC80 from soluble-BP-bleached wheys had lower cardboard flavor and lower aldehyde levels than WPC80 from insoluble-BP-bleached whey. This study suggests that new, soluble (liquid) BP can be used at lower concentrations than insoluble BP to achieve equivalent bleaching and that less residual benzoic acid remains in WPC80 powder from liquid whey

Benzoylation of Ergosterol through Nucleophilic Acyl Substitution and Subsequent Formation of Ergosterol Benzoate Endoperoxide by Reaction with Singlet Oxygen Generated by Photosensitization

ERIC Educational Resources Information Center

Roslaniec, Mary C.; Sanford, Elizabeth M.

2011-01-01

Reactive oxygen species such as singlet oxygen have been a major focus of research in medicine. The effect of singlet oxygen on sterols within biological membranes is becoming increasingly more important. Ergosterol, a vitamin D precursor, is one such sterol. The benzoylation of ergosterol and subsequent reaction with singlet oxygen to form an…

Purification of circular DNA using benzoylated naphthoylated DEAE-cellulose.

PubMed

Gamper, H; Lehman, N; Piette, J; Hearst, J E

1985-04-01

Un-nicked circular DNA can be separated from protein, RNA, and other DNA in a simple three-step protocol consisting of exonuclease III digestion, extraction with benzoylated naphthoylated DEAE-cellulose (BND cellulose) in 1 M NaCl, and alcohol precipitation of the remaining supercoiled DNA. Exonuclease III treatment introduces single-stranded regions into contaminating linear and nicked circular DNA. This DNA, together with most RNA and protein, is adsorbed onto BND cellulose leaving form I DNA in solution. The protocol can be used to purify analytical as well as preparative amounts of supercoiled DNA. This procedure is a substitute for cesium chloride-ethidium bromide gradient ultracentrifugation and gives a comparable yield of pure form I DNA. Other classes of DNA can be isolated by changing the pretreatment step. Selective digestion of linear DNA with lambda exonuclease permits the isolation of both nicked circular and supercoiled DNA while brief heat-induced or alkali-induced denaturation leads to the recovery of rapidly reannealing DNA. In large-scale purifications, the basic protocol is usually preceded by one or more BND cellulose extractions in 1 M NaCl to remove contaminants absorbing UV or inhibiting exonuclease III.

Characterisation of a LoVo subline resistant to a benzoyl mustard derivative of distamycin A (FCE 24517).

PubMed Central

Capolongo, L.; Melegaro, G.; Broggini, M.; Mongelli, N.; Grandi, M.

1993-01-01

Human colon adenocarcinoma cells (LoVo) resistant to the new antitumor agent FCE 24517 [benzoyl-mustard derivative of distamycin A] (LoVo/24517) are resistant to the selecting agent and related molecules as well as to vinblastine, with marginal or no resistance to other antitumour drugs. Treatment with verapamil, tamoxifen, nicergoline or cyclosporin A only partially restores the activity of FCE 24517 against LoVo/24517 cells. Such results suggest that resistance mechanisms possible specific for this class of compounds are operating. Images Figure 2 PMID:8105866

Substitution Effects and Linear Free Energy Relationships During Reduction of 4- Benzoyl-n-(4-substituted Benzyl)pyridinium Cations

NASA Technical Reports Server (NTRS)

Leventis, Nicholas; Zhang, Guo-Hui; Rawashdeh, Abdel-Monem M.; Sotiriou-Leventis, Chariklia; Gray, Hugh R. (Technical Monitor)

2003-01-01

In analogy to 4-(para-substituted benzoyl)-N-methylpyridinium cations (1-X's), the title species (2-X's, -X = -OCH3, -CH3, -H, -Br, -COCH3, -NO2) undergo two reversible, well-separated (E(sub 1/2) greater than or equal to 650 mV) one-electron reductions. The effect of substitution on the reduction potentials of 2-X's is much weaker than the effect of the same substituents on 1-X's: the Hammett rho-values are 0.80 and 0.93 for the 1st- and 2nd-e reduction of 2-X's vs. 2.3 and 3.3 for the same reductions of 1-X's, respectively. Importantly, the nitro group of 2-NO2 undergoes reduction before the 2nd-e reduction of the 4-benzoylpyridinium system. These results suggest that the redox potentials of the 4-benzoylpyridinium system can be course-tuned via p-benzoyl substitution and fine-tuned via para-benzyl substitution. Introducing the recently derived substituent constant of the -NO2(sup)- group (sigma para-NO2(sup)- = -0.97) yields an excellent correlation for the 3rd-e reduction of 2- NO2 (corresponding to the reduction of the carbonyl group) with the 2nd-e reduction of the other 2-X's, and confirms the electron donating properties of -NO2(sup)-.

Dapsone gel 5% in combination with adapalene gel 0.1%, benzoyl peroxide gel 4% or moisturizer for the treatment of acne vulgaris: a 12-week, randomized, double-blind study.

PubMed

Fleischer, Alan B; Shalita, Alan; Eichenfield, Lawrence F; Abramovits, William; Lucky, Anne; Garrett, Steven

2010-01-01

To evaluate the safety and efficacy of dapsone gel 5% in the treatment of acne when used in combination with adapalene gel 0.1%, benzoyl peroxide gel 4% or moisturizer. This was a twelve-week, randomized, double-blind study. Patients aged 12 years and older (n=301) applied dapsone gel twice daily and were randomly assigned (1:1:1) to one of three additional treatments, applied once daily. By week 12, dapsone gel combined with any of the three additional treatments reduced the mean number of inflammatory lesions. However, the authors did not detect a significant difference in the reduction of inflammatory lesions when dapsone was used in combination with adapalene gel or with benzoyl peroxide gel compared to the dapsone plus moisturizer combination group (P=0.052 for both versus moisturizer combination). Patients treated with dapsone gel combined with adapalene showed a significantly better response in reduction in non-inflammatory and total acne lesion count than those who received the moisturizer combination. Local adverse reactions in all three treatment groups were minimal and generally mild in severity. Dapsone gel in combination with adapalene gel or benzoyl peroxide gel is safe and well tolerated for the treatment of acne vulgaris.

Interaction of N-benzoyl-D-phenylalanine and related compounds with the sulphonylurea receptor of beta-cells.

PubMed

Schwanstecher, C; Meyer, M; Schwanstecher, M; Panten, U

1998-03-01

1. The structure activity relationships for the insulin secretagogues N-benzoyl-D-phenylalanine (NBDP) and related compounds were examined at the sulphonylurea receptor level by use of cultured HIT-T15 and mouse pancreatic beta-cells. The affinities of these compounds for the sulphonylurea receptor were compared with their potencies for K(ATP)-channel inhibition. In addition, the effects of cytosolic nucleotides on K(ATP)-channel inhibition by NBDP were investigated. 2. NBDP displayed a dissociation constant for binding to the sulphonylurea receptor (K(D) value) of 11 microM and half-maximally effective concentrations of K(ATP)-channel inhibition (EC50 values) between 2 and 4 microM (in the absence of cytosolic nucleotides or presence of 0.1 mM GDP or 1 mM ADP). 3. In the absence of cytosolic nucleotides or presence of GDP (0.1 mM) maximally effective concentrations of NBDP (0.1-1 mM) reduced K(ATP)-channel activity to 47% and 44% of control, respectively. In the presence of ADP (1 mM), K(ATP)-channel activity was completely suppressed by 0.1 mM NBDP. 4. The L-isomer of N-benzoyl-phenylalanine displayed a 20 fold lower affinity and an 80 fold lower potency than the D-isomer. 5. Introduction of a p-nitro substituent in the D-phenylalanine moiety of NBDP did not decrease lipophilicity but lowered affinity and potency by more than 30 fold. 6. Introduction of a p-amino substituent in the D-phenylalanine moiety of NBDP (N-benzoyl-p-amino-D-phenylalanine, NBADP) reduced lipophilicity and lowered affinity and potency by about 10 fold. This loss of affinity and potency was compensated for by formation of the phenylpropionic acid derivative of NBADP. A similar difference in affinity was observed for the sulphonylurea carbutamide and its phenylpropionic acid derivative. 7. Replacing the benzene ring in the D-phenylalanine moiety of NBDP by a cyclohexyl ring increased lipophilicity, and the K(D) and EC50 values were slightly lower than for NBDP. Exchange of both benzene rings

Interaction of N-benzoyl-D-phenylalanine and related compounds with the sulphonylurea receptor of β-cells

PubMed Central

Schwanstecher, Christina; Meyer, Miriam; Schwanstecher, Mathias; Panten, Uwe

1998-01-01

The structure activity relationships for the insulin secretagogues N-benzoyl-D-phenylalanine (NBDP) and related compounds were examined at the sulphonylurea receptor level by use of cultured HIT-T15 and mouse pancreatic β-cells. The affinities of these compounds for the sulphonylurea receptor were compared with their potencies for KATP-channel inhibition. In addition, the effects of cytosolic nucleotides on KATP-channel inhibition by NBDP were investigated.NBDP displayed a dissociation constant for binding to the sulphonylurea receptor (KD value) of 11 μM and half-maximally effective concentrations of KATP-channel inhibition (EC50 values) between 2 and 4 μM (in the absence of cytosolic nucleotides or presence of 0.1 mM GDP or 1 mM ADP).In the absence of cytosolic nucleotides or presence of GDP (0.1 mM) maximally effective concentrations of NBDP (0.1–1 mM) reduced KATP-channel activity to 47% and 44% of control, respectively. In the presence of ADP (1 mM), KATP-channel activity was completely suppressed by 0.1 mM NBDP.The L-isomer of N-benzoyl-phenylalanine displayed a 20 fold lower affinity and an 80 fold lower potency than the D-isomer.Introduction of a p-nitro substituent in the D-phenylalanine moiety of NBDP did not decrease lipophilicity but lowered affinity and potency by more than 30 fold.Introduction of a p-amino substituent in the D-phenylalanine moiety of NBDP (N-benzoyl-p-amino-D-phenylalanine, NBADP) reduced lipophilicity and lowered affinity and potency by about 10 fold. This loss of affinity and potency was compensated for by formation of the phenylpropionic acid derivative of NBADP. A similar difference in affinity was observed for the sulphonylurea carbutamide and its phenylpropionic acid derivative.Replacing the benzene ring in the D-phenylalanine moiety of NBDP by a cyclohexyl ring increased lipophilicity, and the KD and EC50 values were slightly lower than for NBDP. Exchange of both benzene rings in NBDP by cyclohexyl rings

3-O-Benzyl-6-O-benzoyl-1,2-O-isopropil-idene-5-C-nitro-methyl-a-d-glucofuran-ose.

PubMed

Pampín, Begoña; Valencia, Laura; Estévez, Juan C; Estévez, Ramón J

2009-01-17

The title compound, C(24)H(27)NO(9), is one of the epimers of the Henry reaction of 3-O-benzyl-6-O-benzoyl-2-O-isopropyl-idene-a-d-glucofuran-5-one with nitro-methane. The conformation of the five membered rings is as expected from the precursor compound and the mol-ecule is folded with a dihedral angle of 51.4 (2)° between the aromatic rings. One O-H⋯O hydrogen bond and some intra-molecular and inter-molecular C-H⋯O inter-actions are observed in the structure.

Orientation of N-benzoyl glycine on silver nanoparticles: SERS and DFT studies

NASA Astrophysics Data System (ADS)

Parameswari, A.; Asath, R. Mohamed; Premkumar, R.; Benial, A. Milton Franklin

2017-05-01

Surface enhanced Raman scattering (SERS) studies of N-benzoyl glycine (NBG) adsorbed on silver nanoparticles (AgNPs) was studied by experimental and density functional theory (DFT) approach. Single crystals of NBG were prepared using slow evaporation method. The AgNPs were prepared and characterized. The DFT/ B3PW91 method with LanL2DZ basis set was used to optimize the molecular structure of NBG and NBG adsorbed on silver cluster. The calculated and observed vibrational frequencies were assingned on the basis of potential energy distribution calculation. The reduced band gap value was obtained for NBG adsorbed on silver nanoparticles from the frontier molecular orbitals analysis. Natural bond orbital analysis was carried out to inspect the intra-molecular stabilization interactions, which are responsible for the bio activity and nonlinear optical property of the molecule. The spectral analysis was also evidenced that NBG would adsorb tilted orientation on the silver surface over the binding sites such as lone pair electron of N atom in amine group and through phenyl ring π system.

Effect of N-benzoyl-d-phenylalanine on lipid profile in liver of neonatal streptozotocin diabetic rats.

PubMed

Pari, Leelavinothan; Ashokkumar, Natarajan

2005-10-01

The effect of N-benzoyl-d-phenylalanine (NBDP) and metformin combination treatment on liver lipids and lipid peroxidation markers was studied in neonatal streptozotocin (nSTZ) diabetic rats. Oral administration of NBDP (50, 100 and 200 mg/kg body weight) and metformin (500 mg/kg body weight) for 6 weeks significantly reduced the elevated blood glucose, liver cholesterol, triglycerides, free fatty acids and phospholipids. The combination treatment also caused a significant decrease in hepatic hydroxymethyl glutaryl-coenzyme A reductase, Thiobarbituric Acid Reactive Substances (TBARS) and significant increase in reduced glutathione levels. The results show that NBDP and metformin improve the hepatic lipid profile and antioxidant status in nSTZ diabetic rats. Combination treatment was more effective than either drug alone.

Synthesis and X-ray structural investigation of (5R*,6S*)-1-benzoyl-5-methylthio-6-methoxy-1-azapenam

NASA Astrophysics Data System (ADS)

Krajewski, J. W.; Gluziński, P.; Grochowski, E.; Pupek, K.; Mishnyov, A.; Kemme, A.

1992-08-01

The compound (5R*,6S*)-1-benzoyl-5-methylthio-6-methoxy-1-azapenam ( 3) has been synthesized and its structure investigated by X-ray diffraction. The compound crystallizes in a monoclinic system, space group Cc, Z = 4, a = 12.01(1), b = 16.51(1), c = 8.048(6) Å, β = 115.87(6)°. The structure was solved by direct methods and refined by a full-matrix, least-squares procedure to give R = 0.070, Rw = 0.046, w = 1.34/(σ 2F). The expected cis configuration around the β-lactam ring was fully confirmed.

Acid- and base-catalysis in the mononuclear rearrangement of some (Z)-arylhydrazones of 5-amino-3-benzoyl-1,2,4-oxadiazole in toluene: effect of substituents on the course of reaction.

PubMed

D'Anna, Francesca; Frenna, Vincenzo; Ghelfi, Franco; Marullo, Salvatore; Spinelli, Domenico

2011-04-15

The reaction rates for the rearrangement of eleven (Z)-arylhydrazones of 5-amino-3-benzoyl-1,2,4-oxadiazole 3a-k into the relevant (2-aryl-5-phenyl-2H-1,2,3-triazol-4-yl)ureas 4a-k in the presence of trichloroacetic acid or of piperidine have been determined in toluene at 313.1 K. The results have been related to the effect of the aryl substituent by using Hammett and/or Ingold-Yukawa-Tsuno correlations and have been compared with those previously collected in a protic polar solvent (dioxane/water) as well as with those on the analogous rearrangement of the corresponding (Z)-arylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole 1a-k in benzene. Some light can thus be shed on the general differences of chemical reactivity between protic polar (or dipolar aprotic) and apolar solvents.

Sugar microanalysis by HPLC with benzoylation: improvement via introduction of a C-8 cartridge and a high efficiency ODS column.

PubMed

Miyagi, Michiko; Yokoyama, Hirokazu; Hibi, Toshifumi

2007-07-01

An HPLC protocol for sugar microanalysis based on the formation of ultraviolet-absorbing benzoyl chloride derivatives was improved. Here, samples were prepared with a C-8 cartridge and analyzed with a high efficiency ODS column, in which porous spherical silica particles 3 microm in diameter were packed. These devices allowed us to simultaneously quantify multiple sugars and sugar alcohols up to 10 ng/ml and to provide satisfactory separations of some sugars, such as fructose and myo-inositol and sorbitol and mannitol. This protocol, which does not require special apparatuses, should become a powerful tool in sugar research.

Efficacy of Intense-pulsed Light Therapy with Topical Benzoyl Peroxide 5% versus Benzoyl Peroxide 5% Alone in Mild-to-moderate Acne Vulgaris: A Randomized Controlled Trial.

PubMed

Mokhtari, Fatemeh; Gholami, Maryam; Siadat, Amir Hossein; Jafari-Koshki, Tohid; Faghihi, Gita; Nilforoushzadeh, Mohammad Ali; Hosseini, Sayed Mohsen; Abtahi-Naeini, Bahareh

2017-01-01

Acne vulgaris is a disease of pilosebaceous unit with multifactorial pathogenesis and threats patients' social functioning. There is a growing research to find faster, more effective, and easy to use treatments. The aim of this study is to evaluate the efficacy of benzoyl peroxide 5% (BP) with and without concomitant intense-pulsed light (IPL) therapy in mild-to-moderate acne vulgaris. In this controlled trial, 58 eligible patients with mild-to-moderate acne and Fitzpatrick skin phototype III and IV were randomly allocated to two groups. All patients were asked to use a thin layer of BP every night. The IPL therapy was administered at the end of first, 2 nd , and 3 rd months. Acne Global Severity Scale (AGSS), Acne Severity Index (ASI), and total lesion counting (TLC) along with patient satisfaction were recorded. Patients were also examined 1 month after the final therapeutic visit. The IPL group showed greater reduction in AGSS ( P < 0.001) and TLC ( P = 0.005) than the control group. However, the difference in ASI was not significant ( P = 0.12). Patients in IPL groups were more satisfied than control group ( P < 0.001). Adding IPL to BP can result better response to BP alone. In acne treatment, combination therapy such as IPL and other topical agents should be kept in mind.

Efficacy of Intense-pulsed Light Therapy with Topical Benzoyl Peroxide 5% versus Benzoyl Peroxide 5% Alone in Mild-to-moderate Acne Vulgaris: A Randomized Controlled Trial

PubMed Central

Mokhtari, Fatemeh; Gholami, Maryam; Siadat, Amir Hossein; Jafari-Koshki, Tohid; Faghihi, Gita; Nilforoushzadeh, Mohammad Ali; Hosseini, Sayed Mohsen; Abtahi-Naeini, Bahareh

2017-01-01

Objective: Acne vulgaris is a disease of pilosebaceous unit with multifactorial pathogenesis and threats patients' social functioning. There is a growing research to find faster, more effective, and easy to use treatments. The aim of this study is to evaluate the efficacy of benzoyl peroxide 5% (BP) with and without concomitant intense-pulsed light (IPL) therapy in mild-to-moderate acne vulgaris. Methods: In this controlled trial, 58 eligible patients with mild-to-moderate acne and Fitzpatrick skin phototype III and IV were randomly allocated to two groups. All patients were asked to use a thin layer of BP every night. The IPL therapy was administered at the end of first, 2nd, and 3rd months. Acne Global Severity Scale (AGSS), Acne Severity Index (ASI), and total lesion counting (TLC) along with patient satisfaction were recorded. Patients were also examined 1 month after the final therapeutic visit. Findings: The IPL group showed greater reduction in AGSS (P < 0.001) and TLC (P = 0.005) than the control group. However, the difference in ASI was not significant (P = 0.12). Patients in IPL groups were more satisfied than control group (P < 0.001). Conclusion: Adding IPL to BP can result better response to BP alone. In acne treatment, combination therapy such as IPL and other topical agents should be kept in mind. PMID:29417078

[Antibiotics, azelaic acid and benzoyl peroxide in topical acne therapy].

PubMed

Fluhr, Joachim W; Degitz, Klaus

2010-03-01

Benzoyl peroxide was introduced as a basic treatment already in acne therapy 1934. The mechanism of action is the reduction of anaerobe bacteria by strong oxidation processes. No resistancies have been ever reported. BPO is available in 2.5, 5 and 10 % formulations. Its efficacy is slightly related to the strength of concentrations, but the side effect profile with burning, erythema and desquamation is increasing with concentrations. BPO 5% mostly is efficient enough to control acne of grades I to II according to the Kligman & Plewig classification. BPO my bleach clothes and hair. It is the most costeffective topical drug in acne of grades I-II. Inflammatory acne of the papular-pustular type I-II can also be treated by topical antibiotics such as erythromycin, clindamycin, and, less frequent and today not anymore recommended tetracyclines. Mechanism of action is not alone an antibacterial but anti inflammatory effect. The efficacy and penetration of the topical antibiotics between the groups are similar. Randomized studies have shown that concentrations of 2-4% are equivalent to oral tetracycline and minocycline in mild to moderate acne. Combinatory formulations with BPO and with retinoids enhance the efficacy significantly. Topical antibiotics plus BPO show less bacterial resistancies as topical antibiotics alone. Antibiotics should therefore not be used as monotherapy. Moreover gram negative folliculitis may develop. Azelaic acid is acting as an antimicrobial and can also reduce comedones. It can also be used in pregnancy and during the lactation period.

Carcinogenicity of benzyl chloride, benzal chloride, benzotrichloride and benzoyl chloride in mice by skin application.

PubMed

Fukuda, K; Matsushita, H; Sakabe, H; Takemoto, K

1981-10-01

The carcinogenicity of benzyl chloride (BYC), benzal chloride (BAC), benzotrichloride (BTC) and benzoyl chloride (BOC), which were suspected as causative agents of lung cancer and maxillary malignant lymphoma of workers employed in factories producing BOC, was examined by skin applications in female ICR mice. After rather high dose exposure, BTC exhibited leukemogenic and pulmonary tumorigenic activities as well as potent dermal carcinogenic activity. After administration of the chemicals at the dose of 2.3 microliter/animal, twice a week for 50 weeks, BTC induced 68% incidence of skin cancers and 58% incidence of pulmonary tumors (including 10% of lung carcinomas) within 399 days. Incidence of skin cancers was 58% for BAC, 15% for BYC and 10% for BOC within 560 days. Considering the extent of possible exposure of the workers to these chemicals in the working environment and the carcinogenic potency of the chemicals tested, it can be concluded that BTC was very probably responsible for causing the cancers seen int he workers employed in manufacturing BOC.

Design, synthesis, and anti-melanogenic effects of (E)-2-benzoyl-3-(substituted phenyl)acrylonitriles

PubMed Central

Yun, Hwi Young; Kim, Do Hyun; Son, Sujin; Ullah, Sultan; Kim, Seong Jin; Kim, Yeon-Jeong; Yoo, Jin-Wook; Jung, Yunjin; Chun, Pusoon; Moon, Hyung Ryong

2015-01-01

Background Tyrosinase is the most prominent target for inhibitors of hyperpigmentation because it plays a critical role in melaninogenesis. Although many tyrosinase inhibitors have been identified, from both natural and synthetic sources, there remains a considerable demand for novel tyrosinase inhibitors that are safer and more effective. Methods (E)-2-Benzoyl-3-(substituted phenyl)acrylonitriles (BPA analogs) with a linear β-phenyl-α,β-unsaturated carbonyl scaffold were designed and synthesized as potential tyrosinase inhibitors. We evaluated their effects on cellular tyrosinase activity and melanin biosynthesis in murine B16F10 melanoma cells and their ability to inhibit mushroom tyrosinase activity. Results BPA analogs exhibited inhibitory activity against mushroom tyrosinase. In particular, BPA13 significantly suppressed melanin biosynthesis and inhibited cellular tyrosinase activity in B16F10 cells in a dose-dependent manner. A docking study revealed that BPA13 had higher binding affinity for tyrosinase than kojic acid. Conclusion BPA13, which possesses a linear β-phenyl-α,β-unsaturated carbonyl scaffold, is a potential candidate skin-whitening agent and treatment for diseases associated with hyperpigmentation. PMID:26347064

Supra-molecular architecture in a co-crystal of the N(7)-H tautomeric form of N (6)-benzoyl-adenine with adipic acid (1/0.5).

PubMed

Swinton Darious, Robert; Thomas Muthiah, Packianathan; Perdih, Franc

2016-06-01

The asymmetric unit of the title co-crystal, C12H9N5O·0.5C6H10O4, consists of one mol-ecule of N (6)-benzoyl-adenine (BA) and one half-mol-ecule of adipic acid (AA), the other half being generated by inversion symmetry. The dihedral angle between the adenine and phenyl ring planes is 26.71 (7)°. The N (6)-benzoyl-adenine mol-ecule crystallizes in the N(7)-H tautomeric form with three non-protonated N atoms. This tautomeric form is stabilized by intra-molecular N-H⋯O hydrogen bonding between the carbonyl (C=O) group and the N(7)-H hydrogen atom on the Hoogsteen face of the purine ring, forming an S(7) ring motif. The two carboxyl groups of adipic acid inter-act with the Watson-Crick face of the BA mol-ecules through O-H⋯N and N-H⋯O hydrogen bonds, generating an R 2 (2)(8) ring motif. The latter units are linked by N-H⋯N hydrogen bonds, forming layers parallel to (10-5). A weak C-H⋯O hydrogen bond is also present, linking adipic acid mol-ecules in neighbouring layers, enclosing R (2) 2(10) ring motifs and forming a three-dimensional structure. C=O⋯π and C-H⋯π inter-actions are also present in the structure.

3-O-Benzyl-6-O-benzoyl-1,2-O-isopropil­idene-5-C-nitro­methyl-a-d-glucofuran­ose

PubMed Central

Pampín, Begoña; Valencia, Laura; Estévez, Juan C.; Estévez, Ramón J.

2009-01-01

The title compound, C24H27NO9, is one of the epimers of the Henry reaction of 3-O-benzyl-6-O-benzoyl-2-O-isopropyl­idene-a-d-glucofuran-5-one with nitro­methane. The conformation of the five membered rings is as expected from the precursor compound and the mol­ecule is folded with a dihedral angle of 51.4 (2)° between the aromatic rings. One O—H⋯O hydrogen bond and some intra­molecular and inter­molecular C—H⋯O inter­actions are observed in the structure. PMID:21581936

Detecting benzoyl peroxide in wheat flour by line-scan macro-scale Raman chemical imaging

NASA Astrophysics Data System (ADS)

Qin, Jianwei; Kim, Moon S.; Chao, Kuanglin; Gonzalez, Maria; Cho, Byoung-Kwan

2017-05-01

Excessive use of benzoyl peroxide (BPO, a bleaching agent) in wheat flour can destroy flour nutrients and cause diseases to consumers. A macro-scale Raman chemical imaging method was developed for direct detection of BPO mixed in the wheat flour. A 785 nm line laser was used in a line-scan Hyperspectral Raman imaging system. Raman images were collected from wheat flour mixed with BPO at eight concentrations (w/w) from 50 to 6,400 ppm. A sample holder (150×100×2 mm3) was used to present a thin layer (2 mm thick) of the powdered sample for image acquisition. A baseline correction method was used to correct the fluctuating fluorescence signals from the wheat flour. To isolate BPO particles from the flour background, a simple thresholding method was applied to the single-band fluorescence-free images at a unique Raman peak wavenumber (i.e., 1001 cm-1) preselected for the BPO detection. Chemical images were created to detect and map the BPO particles. Limit of detection for the BPO was estimated in the order of 50 ppm, which is on the same level with regulatory standards.

A skincare combined with combination of adapalene and benzoyl peroxide provides a significant adjunctive efficacy and local tolerance benefit in adult women with mild acne.

PubMed

Bouloc, A; Roo, E; Imko-Walczuk, B; Moga, A; Chadoutaud, B; Dréno, B

2017-10-01

Acne in adult women is an increasing reason for dermatological consultations. The aim of this study was to assess in adult women with mild acne the efficacy and tolerance of a daily adjunctive application of a skincare (Normaderm ® , Laboratoires Vichy, France) to a fixed combination of adapalene/benzoyl peroxide daily or every other evening and a standard emollient. Subjects were randomized to receive the fixed combination applied either every evening or every other evening and a daily application of the standard emollient and the test care or a once daily application of the fixed combination and the standard emollient alone. Clinical evaluations at Day 0, Day 45 and Day 90 included the count of acne lesions, assessment of clinical improvement and local tolerance. The quantitative lipid profile of the stratum corneum of the forehead was also determined. After 90 days of application, acne had improved in all 299 subjects with a statistically significant difference in favour of the test care regimens (P < 0.05). Moreover, skin quality, subject satisfaction, skin discomfort and sebum composition were in favour of these regimens. In conclusion, the tested skincare combined with a fixed adapalene and benzoyl peroxide combination provides a significant adjunctive efficacy and local tolerance benefit in adult women with mild acne. © 2017 The Authors. Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of European Academy of Dermatology and Venereology.

Characterization of some amino acid derivatives of benzoyl isothiocyanate: Crystal structures and theoretical prediction of their reactivity

NASA Astrophysics Data System (ADS)

Odame, Felix; Hosten, Eric C.; Betz, Richard; Lobb, Kevin; Tshentu, Zenixole R.

2015-11-01

The reaction of benzoyl isothiocyanate with L-serine, L-proline, D-methionine and L-alanine gave 2-[(benzoylcarbamothioyl)amino]-3-hydroxypropanoic acid (I), 1-(benzoylcarbamothioyl)pyrrolidine-2-carboxylic acid (II), 2-[(benzoylcarbamothioyl)amino]-4-(methylsulfanyl)butanoic acid (III) and 2-[(benzoylcarbamothioyl)amino]propanoic acid (IV), respectively. The compounds have been characterized by IR, NMR, microanalyses and mass spectrometry. The crystal structures of all the compounds have also been discussed. Compound II showed rotamers in solution. DFT calculations of the frontier orbitals of the compounds have been carried out to ascertain the groups that contribute to the HOMO and LUMO, and to study their contribution to the reactivity of these compounds. The calculations indicated that the carboxylic acid group in these compounds is unreactive hence making the conversion to benzimidazoles via cyclization on the carboxylic acids impractical. This has been further confirmed by the reaction of compounds I-IV, respectively, with o-phenylene diamine which was unsuccessful but gave compound V.

Effect of N-benzoyl-D-phenylalanine and metformin on carbohydrate metabolic enzymes in neonatal streptozotocin diabetic rats.

PubMed

Ashokkumar, Natarajan; Pari, Leelavinothan

2005-01-01

The effect of N-benzoyl-D-phenylalanine (NBDP) and metformin was studied on the activities of carbohydrate metabolic enzymes in neonatal streptozotocin (nSTZ) non-insulin-dependent diabetic rats. To induce non-insulin-dependent diabetes mellitus (NIDDM), single dose injection of streptozotocin (STZ; 100 mg/kg body weight; i.p.) was given to 2-day old rats. After 10-12 weeks, rats weighing >150 g were selected for screening in NIDDM model, they were checked for fasting blood glucose concentrations to conform the status of NIDDM. NBDP (50,100 and 200 mg/kg body weight) was administered orally for 6 weeks into the confirmed diabetic rats. The activities of gluconeogenic enzymes were significantly increased, whereas the activities of hexokinase and glucose-6-phosphate dehydrogenase were significantly decreased in nSTZ diabetic rats. Both NBDP and metformin were able to restore the altered enzyme activities to almost control concentrations. Combination treatment was more effective than either drug alone. The administration of NBDP along with metformin to nSTZ diabetic rats normalizes blood glucose and causes marked improvement of altered carbohydrate metabolic enzymes during diabetes.

Synthesis, spectroscopic and theoretical studies of ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate butanol solvate

NASA Astrophysics Data System (ADS)

Koca, İrfan; Sert, Yusuf; Gümüş, Mehmet; Kani, İbrahim; Çırak, Çağrı

2014-01-01

We have synthesized ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate (2) by the reaction of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride (1), ammonium thiocyanate and ethyl 3-aminobut-2-enoate and then characterized by elemental analyses, IR, Raman, 1H NMR, 13C NMR and X-ray diffraction methods. The experimental and theoretical vibrational spectra of 2 were investigated. The experimental FT-IR (4000-400 cm-1) and Laser-Raman spectra (4000-100 cm-1) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles) were calculated using Ab Initio Hartree Fock (HF), Density Functional Theory (B3LYP) methods with 6-311++G(d,p) basis set by Gaussian 09W program. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were calculated.

Glycoprotein changes in non-insulin dependent diabetic rats: effect of N-benzoyl-D-phenylalanine and metformin.

PubMed

Pari, Leelavinothan; Ashokkumar, Natarajan

2006-01-01

The effect of N-benzoyl-D-phenylalanine (NBDP) and metformin on neonatal streptozotocin (nSTZ) induced diabetes has been studied on plasma and tissue glycoproteins. In some pathological conditions, such as cancer, rheumatoid arthritis and diabetes, there is an abnormal glycosylation of acute phase serum proteins. As most serum proteins are produced in the liver, we have examined glycoprotein metabolism in diabetic condition. To induce non-insulin-dependent diabetes mellitus (NIDDM) a single dose of streptozotocin (100 mg/kg body weight) was injected into two day old rats. After 10-12 weeks, rats weighing above 150 g were selected for NIDDM model. In these rat, blood glucose and plasma glycoproteins were significantly increased whereas plasma insulin was significantly decreased. There was a significant decrease in the level of sialic acid and elevated levels of hexose, hexosamine and fucose in tissues. Oral administration of NBDP and metformin to diabetic rats decreased blood glucose and plasma glycoproteins. Plasma insulin and tissue sialic acid were increased whereas tissue concentrations of hexose, hexosamine and fucose were near normal. Our study suggests that NBDP and metformin possess a significant beneficial effect on glycoproteins in addition to their antidiabetic effect.

Benzoyl Peroxide as an Efficient Dopant for Spiro-OMeTAD in Perovskite Solar Cells.

PubMed

Liu, Qiuju; Fan, Lisheng; Zhang, Qin'e; Zhou, An'an; Wang, Baozeng; Bai, Hua; Tian, Qingyong; Fan, Bin; Zhang, Tongyi

2017-08-10

Although organic small molecule spiro-OMeTAD is widely used as a hole-transport material in perovskite solar cells, its limited electric conductivity poses a bottleneck in the efficiency improvement of perovskite solar cells. Here, a low-cost and easy-fabrication technique is developed to enhance the conductivity and hole-extraction ability of spiro-OMeTAD by doping it with commercially available benzoyl peroxide (BPO). The experimental results show that the conductivity increases several orders of magnitude, from 6.2×10 -6  S cm -1 for the pristine spiro-OMeTAD to 1.1×10 -3  S cm -1 at 5 % BPO doping and to 2.4×10 -2  S cm -1 at 15 % BPO doping, which considerably outperform the conductivity of 4.62×10 -4  S cm -1 for the currently used oxygen-doped spiro-OMeTAD. The fluorescence spectra suggest that the BPO-doped spiro-OMeTAD-OMeTAD layer is able to efficiently extract holes from CH 3 NH 3 PbI 3 and thus greatly enhances the charge transfer. The BPO-doped spiro-OMeTAD is used in the fabrication of perovskite solar cells, which exhibit enhancement in the power conversion efficiency. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Combined n-benzoyl-d-phenylalanine and metformin treatment reverses changes in the fatty acid composition of streptozotocin diabetic rats.

PubMed

Kumar, Natarajan Ashok; Pari, Leelavinothan

2006-01-01

The present investigation was carried out to evaluate the effect of N-benzoyl-D-phenylalanine (NBDP) and metformin on blood glucose, plasma insulin, and on the fatty acid composition of total lipids in the livers and kidneys of control and experimental diabetic rats. When compared with nondiabetic control rats, neonatal streptozotocin (nSTZ) diabetic rats showed a significant increase in blood glucose and decreased plasma insulin. Analysis of fatty acids revealed a significant increase in the concentration of palmitic, stearic, and oleic acids in liver and kidney, whereas linolenic and arachidonic acids were significantly decreased. In diabetic rats, the oral administration of combined NBDP/metformin for 6 wk decreased the high concentrations of palmitic, stearic, and oleic acids and elevated the low levels of linolenic and arachidonic acids. The results suggest that the NBDP/metformin combination exhibits both antidiabetic and antihyperlipidemic effects in nSTZ diabetic rats and prevents the fatty acid changes produced during diabetes.

Synthesis, spectroscopic and theoretical studies of ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate butanol solvate.

PubMed

Koca, İrfan; Sert, Yusuf; Gümüş, Mehmet; Kani, İbrahim; Çırak, Çağrı

2014-01-24

We have synthesized ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate (2) by the reaction of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride (1), ammonium thiocyanate and ethyl 3-aminobut-2-enoate and then characterized by elemental analyses, IR, Raman, (1)H NMR, (13)C NMR and X-ray diffraction methods. The experimental and theoretical vibrational spectra of 2 were investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles) were calculated using Ab Initio Hartree Fock (HF), Density Functional Theory (B3LYP) methods with 6-311++G(d,p) basis set by Gaussian 09W program. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were calculated. Copyright © 2013 Elsevier B.V. All rights reserved.

Colorimetric determination of Al(III) based on the aggregation of gold nanoparticles functionalized with novel 4-benzoyl pyrazolone derivative

NASA Astrophysics Data System (ADS)

Abubaker, Mariam; Ngah, Che Wan Zanariah Che Wan; Ahmad, Musa; Kuswandi, Bambang

2018-06-01

A sensitive and selective colorimetric method has been developed for detection of Al3+ ion using 4-benzoyl pyrazolone-functionalized gold nanoparticles (BMPBP-AuNPs) as novel colorimetric probes. The BMPBP-AuNPs were characterized by UV-visible spectrometry and transmission electron microscopy (TEM). It was found that the addition of the Al3+ ions led to a rapid aggregation of the BMPBP-AuNPs, which changed the color of the mixture from red to blue. Furthermore, there was a shift in the characteristic surface plasmon resonance (SPR) peak from 524 to 650 nm of BMPBP-AuNPs, which confirmed that a good linear relation (R2 = 0.9935) was present between the absorption ratio of 524 and 650 nm. Also, the assay detected the Al3+ ion concentrations in the linear range 0-12 ppm with the detection limit is 0.05 ppm. Finally, the synthesized BMPBP-AuNPs were successfully used as a colorimetric sensor for the selective and sensitive detection of the Al3+ ions in water samples.

Discovery of novel 2-aryl-4-benzoyl-imidazoles targeting the colchicines binding site in tubulin as potential anticancer agents

PubMed Central

Chen, Jianjun; Wang, Zhao; Li, Chien-Ming; Lu, Yan; Vaddady, Pavan K.; Meibohm, Bernd; Dalton, James T.; Miller, Duane D.; Li, Wei

2010-01-01

A series of 2-aryl-4-benzoyl-imidazoles (ABI) was synthesized as a result of structural modifications based on the previous set of 2-aryl-imidazole-4-carboxylic amide (AICA) derivatives and 4-substituted methoxylbenzoyl-aryl-thiazoles (SMART). The average IC50 of the most active compound (5da) was 15.7 nM. ABI analogs have substantially improved aqueous solubility (48.9 μg/mL for 5ga vs. 0.909 μg/mL for SMART-1, 0.137 μg/mL for paclitaxel, and 1.04 μg/mL for Combretastatin A4). Mechanism of action studies indicate that the anticancer activity of ABI analogs is through inhibition of tubulin polymerization by interacting with the colchicine binding site. Unlike paclitaxel and colchicine, the ABI compounds were equally potent against multidrug resistant cancer cells and the sensitive parental melanoma cancer cells. In vivo results indicated that 5cb was more effective than DTIC in inhibiting melanoma xenograph tumor growth. Our results suggest that the novel ABI compounds may be developed to effectively treat drug-resistant tumors. PMID:20919720

Efficacy and safety of tretinoin 0.025%/clindamycin phosphate 1.2% gel in combination with benzoyl peroxide 6% cleansing cloths for the treatment of facial acne vulgaris.

PubMed

Zeichner, Joshua A; Wong, Vicky; Linkner, Rita V; Haddican, Madelaine

2013-03-01

Combination therapy using medications with complementary mechanisms of action is the standard of care in treating acne. We report results of a clinical trial evaluating the use of a fixed-dose tretinoin 0.025%/clindamycin phosphate 1.2% (T/CP) gel in combination with a benzoyl peroxide 6% foaming cloth compared with T/CP alone for facial acne. At week 12, the combination therapy group showed a trend toward greater efficacy compared with T/CP alone. There was a high success rate observed in the study, which may be attributable to the large percentage of adult female acne patients enrolled. Cutaneous adverse events were not statistically different in using combination therapy compared with T/CP alone.

Identification and characterization of the tungsten-containing class of benzoyl-coenzyme A reductases

PubMed Central

Kung, Johannes W.; Löffler, Claudia; Dörner, Katerina; Heintz, Dimitri; Gallien, Sébastien; Van Dorsselaer, Alain; Friedrich, Thorsten; Boll, Matthias

2009-01-01

Aromatic compounds are widely distributed in nature and can only be biomineralized by microorganisms. In anaerobic bacteria, benzoyl-CoA (BCoA) is a central intermediate of aromatic degradation, and serves as substrate for dearomatizing BCoA reductases (BCRs). In facultative anaerobes, the mechanistically difficult reduction of BCoA to cyclohexa-1,5-dienoyl-1-carboxyl-CoA (dienoyl-CoA) is driven by a stoichiometric ATP hydrolysis, catalyzed by a soluble, three [4Fe-4S] cluster-containing BCR. In this work, an in vitro assay for BCR from the obligately anaerobic Geobacter metallireducens was established. It followed the reverse reaction, the formation of BCoA from dienoyl-CoA in the presence of various electron acceptors. The benzoate-induced activity was highly specific for dienoyl-CoA (Km = 24 ± 4 μM). The corresponding oxygen-sensitive enzyme was purified by several chromatographic steps with a 115-fold enrichment and a yield of 18%. The 185-kDa enzyme comprised 73- and 20-kDa subunits, suggesting an α2β2-composition. MS analysis revealed the subunits as products of the benzoate-induced bamBC genes. The αβ unit contained 0.9 W, 15 Fe, and 12.5 acid-labile sulfur. Results from EPR spectroscopy suggest the presence of one [3Fe-4S]0/+1 and three [4Fe-4S]+1/+2 clusters per αβ unit; oxidized BamBC exhibited an EPR signal typical for a W(V) species. The FeS clusters and the W- cofactor could only be fully reduced by dienoyl-CoA. BamBC represents the prototype of a previously undescribed class of dearomatizing BCRs that differ completely from the ATP-dependent enzymes from facultative anaerobes. PMID:19815533

Synthesis, spectroscopic and structural characterization of 5-benzoyl-4-phenyl-2-methylthio-1H-pyrimidine with theoretical calculations using density functional theory

NASA Astrophysics Data System (ADS)

İnkaya, Ersin; Dinçer, Muharrem; Şahan, Emine; Yıldırım, İsmail

2013-10-01

In this paper, we will report a combined experimental and theoretical investigation of the molecular structure and spectroscopic parameters (FT-IR, 1H NMR, 13C NMR) of 5-benzoyl-4-phenyl-2-methylthio-1H-pyrimidine. The compound crystallizes in the triclinic space group P-1 with Z = 2. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d,p) and 6-311++G(d,p) basis sets in ground state and compared with the experimental data. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential (ESP). Also, non-linear optical properties of the title compound were performed at B3LYP/6-311++G(d,p) level. The theoretical results showed an excellent agreement with the experimental values.

Benzoyl Halides as Alternative Precursors for the Colloidal Synthesis of Lead-Based Halide Perovskite Nanocrystals

PubMed Central

2018-01-01

We propose here a new colloidal approach for the synthesis of both all-inorganic and hybrid organic–inorganic lead halide perovskite nanocrystals (NCs). The main limitation of the protocols that are currently in use, such as the hot injection and the ligand-assisted reprecipitation routes, is that they employ PbX2 (X = Cl, Br, or I) salts as both lead and halide precursors. This imposes restrictions on being able to precisely tune the amount of reaction species and, consequently, on being able to regulate the composition of the final NCs. In order to overcome this issue, we show here that benzoyl halides can be efficiently used as halide sources to be injected in a solution of metal cations (mainly in the form of metal carboxylates) for the synthesis of APbX3 NCs (in which A = Cs+, CH3NH3+, or CH(NH2)2+). In this way, it is possible to independently tune the amount of both cations and halide precursors in the synthesis. The APbX3 NCs that were prepared with our protocol show excellent optical properties, such as high photoluminescence quantum yields, low amplified spontaneous emission thresholds, and enhanced stability in air. It is noteworthy that CsPbI3 NCs, which crystallize in the cubic α phase, are stable in air for weeks without any postsynthesis treatment. The improved properties of our CsPbX3 perovskite NCs can be ascribed to the formation of lead halide terminated surfaces, in which Cs cations are replaced by alkylammonium ions. PMID:29378131

Benzoyl Halides as Alternative Precursors for the Colloidal Synthesis of Lead-Based Halide Perovskite Nanocrystals.

PubMed

Imran, Muhammad; Caligiuri, Vincenzo; Wang, Mengjiao; Goldoni, Luca; Prato, Mirko; Krahne, Roman; De Trizio, Luca; Manna, Liberato

2018-02-21

We propose here a new colloidal approach for the synthesis of both all-inorganic and hybrid organic-inorganic lead halide perovskite nanocrystals (NCs). The main limitation of the protocols that are currently in use, such as the hot injection and the ligand-assisted reprecipitation routes, is that they employ PbX 2 (X = Cl, Br, or I) salts as both lead and halide precursors. This imposes restrictions on being able to precisely tune the amount of reaction species and, consequently, on being able to regulate the composition of the final NCs. In order to overcome this issue, we show here that benzoyl halides can be efficiently used as halide sources to be injected in a solution of metal cations (mainly in the form of metal carboxylates) for the synthesis of APbX 3 NCs (in which A = Cs + , CH 3 NH 3 + , or CH(NH 2 ) 2 + ). In this way, it is possible to independently tune the amount of both cations and halide precursors in the synthesis. The APbX 3 NCs that were prepared with our protocol show excellent optical properties, such as high photoluminescence quantum yields, low amplified spontaneous emission thresholds, and enhanced stability in air. It is noteworthy that CsPbI 3 NCs, which crystallize in the cubic α phase, are stable in air for weeks without any postsynthesis treatment. The improved properties of our CsPbX 3 perovskite NCs can be ascribed to the formation of lead halide terminated surfaces, in which Cs cations are replaced by alkylammonium ions.

Synthesis and Characterization of Ru(II) Tris(1,1O-phenanthroline)-Electron Acceptor Dyads Incorporating the 4-benzoyl-N-methylpyridinium Cation or N-Benzyl-N'-methyl-viologen. Improving the Dynamic Range, Sensitivity and Response Time of Sol-Gel Based Optical Oxygen Sensors

NASA Technical Reports Server (NTRS)

Leventis, Nicholas; Rawashdeh, Abdel-Monen M.; Elder, Ian A.; Yang, Jinhua; Dass, Amala; Sotiriou-Leventis, Chariklia

2004-01-01

The title compounds (1 and 2, above) were synthesized by Sonogashira coupling reactions of appropriate Ru(1I) complexes with the electron a cceptors. Characterization was conducted in solution and in frozen ma trices. Finally, the title compounds were evaluated as dopants of sol-gel materials. It was found that the intramolecular quenching efficie ncy of 4-benzoyl-Nmethylpyridinium cation in solution depends on the solvent: photoluminescence is quenched completely in CH,CN, but not i n methanol or ethanol. On the other hand, intramolecular emission que nching by 4-benzyl-N-methyl viologen is complete in all solvents. The difference between the two quenchers is traced electrochemically to t he solvation of the 4-benzoyl-Nmethylpyridiniums by alcohol. In froze n matrices or adsorbed on the surfaces of silica aerogel, both Ru(I1) complex/electron acceptor dyads of this study are photoluminescent, and the absence of quenching has been traced to the environmental rigi dity. When doped aerogels are cooled at 77 K, the emission intensity increases by approximately 4x, and the spectra shift to the blue, analogous to what is observed with Ru(I1) complexes in solutions undergoi ng fluid-to-rigid transition. However, in contrast to frozen solution s, the luminescent moieties in the bulk of aerogels kept at low tempe ratures are still accessible to gas-phase quenchers diffusing through the mesopores, leading to more sensitive platforms for sensors than o ther room-temperature configurations. Thus the photoluminescence of o ur Ru(I1) complex dyads adsorbed on aerogel is quenchable by O2 both at room temperature and at 77 K. Furthermore, it was also found that O 2 modulates the photoluminescence of aerogels doped with 4-benzoyl -N -methylpyridinium-based dyads over a wider dynamic range compared wi th aerogels doped with either our vislogen-based dyads or with Ru(I1) tris(1,lO-phenanthroline) itself.

Synthesis, characterization and molecular modeling of some transition metal complexes of Schiff base derived from 5-aminouracil and 2-benzoyl pyridine

NASA Astrophysics Data System (ADS)

Abdel-Monem, Yasser K.; Abouel-Enein, Saeyda A.; El-Seady, Safa M.

2018-01-01

Multidentate Schiff base (H2L) ligand results from condensation of 5-aminouracil and 2-benzoyl pyridine and its metal chloride (Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Fe(III), Cr(III), Ru(III), Zr(IV) and Hf(IV)) complexes were prepared. The structural features of the ligand and its metal complexes were confirmed by elemental analyses, spectroscopic methods (IR, UV-Vis, 1H NMR, mass), magnetic moment measurements and thermal studies. The data refer to the ligand coordinates with metal ions in a neutral form and shows different modes of chelation toward the metal atom. All complexes have octahedral skeleton structure, tetrahedrally Mn(II), Ni(II), trigonalbipyramidal Co(II) and square planner Pd(II). Thermal decomposition of complexes as well as the interaction of different types of solvent of crystallization are assigned by thermogravimetric analysis. Molecular modeling of prepared complexes were investigated to study the expected anticancer activities of the prepared complexes. All metal complexes have no interaction except the complexes of Pd(II), Fe(III) and Mn(II).

Kinetics of the hydrolysis of N-benzoyl-l-serine methyl ester catalysed by bromelain and by papain. Analysis of modifier mechanisms by lattice nomography, computational methods of parameter evaluation for substrate-activated catalyses and consequences of postulated non-productive binding in bromelain- and papain-catalysed hydrolyses

PubMed Central

Wharton, Christopher W.; Cornish-Bowden, Athel; Brocklehurst, Keith; Crook, Eric M.

1974-01-01

1. N-Benzoyl-l-serine methyl ester was synthesized and evaluated as a substrate for bromelain (EC 3.4.22.4) and for papain (EC 3.4.22.2). 2. For the bromelain-catalysed hydrolysis at pH7.0, plots of [S0]/vi (initial substrate concn./initial velocity) versus [S0] are markedly curved, concave downwards. 3. Analysis by lattice nomography of a modifier kinetic mechanism in which the modifier is substrate reveals that concave-down [S0]/vi versus [S0] plots can arise when the ratio of the rate constants that characterize the breakdown of the binary (ES) and ternary (SES) complexes is either less than or greater than 1. In the latter case, there are severe restrictions on the values that may be taken by the ratio of the dissociation constants of the productive and non-productive binary complexes. 4. Concave-down [S0]/vi versus [S0] plots cannot arise from compulsory substrate activation. 5. Computational methods, based on function minimization, for determination of the apparent parameters that characterize a non-compulsory substrate-activated catalysis are described. 6. In an attempt to interpret the catalysis by bromelain of the hydrolysis of N-benzoyl-l-serine methyl ester in terms of substrate activation, the general substrate-activation model was simplified to one in which only one binary ES complex (that which gives rise directly to products) can form. 7. In terms of this model, the bromelain-catalysed hydrolysis of N-benzoyl-l-serine methyl ester at pH7.0, I=0.1 and 25°C is characterized by Km1 (the dissociation constant of ES)=1.22±0.73mm, k (the rate constant for the breakdown of ES to E+products, P)=1.57×10−2±0.32×10−2s−1, Ka2 (the dissociation constant that characterizes the breakdown of SES to ES and S)=0.38±0.06m, and k′ (the rate constant for the breakdown of SES to E+P+S)=0.45±0.04s−1. 8. These parameters are compared with those in the literature that characterize the bromelain-catalysed hydrolysis of α-N-benzoyl-l-arginine ethyl ester and

Efficacy and safety of a ceramide containing moisturizer followed by fixed-dose clindamycin phosphate 1.2%/benzoyl peroxide 2.5% gel in the morning in combination with a ceramide containing moisturizer followed by tretinoin 0.05% gel in the evening for the treatment of facial acne vulgaris.

PubMed

Zeichner, Joshua A; Patel, Rita V; Haddican, Madelaine; Wong, Vicky

2012-06-01

Combination therapy addressing multiple pathogenic factors should be used to achieve optimal outcomes in treating acne. The following study demonstrated both safety and efficacy of fixed-dose clindamycin phosphate 1.2%/benzoyl peroxide 2.5% in the morning with micronized tretinoin 0.05% gel in the evening. Both products were applied to the skin following the use of a ceramide containing moisturizing lotion.

Synthesis, spectroscopic and structural characterization of 5-benzoyl-4-phenyl-2-methylthio-1H-pyrimidine with theoretical calculations using density functional theory.

PubMed

Inkaya, Ersin; Dinçer, Muharrem; Sahan, Emine; Yıldırım, Ismail

2013-10-01

In this paper, we will report a combined experimental and theoretical investigation of the molecular structure and spectroscopic parameters (FT-IR, (1)H NMR, (13)C NMR) of 5-benzoyl-4-phenyl-2-methylthio-1H-pyrimidine. The compound crystallizes in the triclinic space group P-1 with Z=2. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d,p) and 6-311++G(d,p) basis sets in ground state and compared with the experimental data. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential (ESP). Also, non-linear optical properties of the title compound were performed at B3LYP/6-311++G(d,p) level. The theoretical results showed an excellent agreement with the experimental values. Copyright © 2013 Elsevier B.V. All rights reserved.

Sensitive quantitation of polyamines in plant foods by ultrasound-assisted benzoylation and dispersive liquid-liquid microextraction with the aid of experimental designs.

PubMed

Pinto, Edgar; Melo, Armindo; Ferreira, Isabel M P L V O

2014-05-14

A new method involving ultrasound-assisted benzoylation and dispersive liquid-liquid microextraction was optimized with the aid of chemometrics for the extraction, cleanup, and determination of polyamines in plant foods. Putrescine, cadaverine, spermidine, and spermine were derivatized with 3,5-dinitrobenzoyl chloride and extracted by dispersive liquid-liquid microextraction using acetonitrile and carbon tetrachloride as dispersive and extraction solvents, respectively. Two-level full factorial design and central composite design were applied to select the most appropriate derivatization and extraction conditions. The developed method was linear in the 0.5-10.0 mg/L range, with a R(2) ≥ 0.9989. Intra- and interday precisions ranged from 0.8 to 6.9% and from 3.0 to 10.3%, respectively, and the limit of detection ranged between 0.018 and 0.042 μg/g of fresh weight. This method was applied to the analyses of six different types of plant foods, presenting recoveries between 81.7 and 114.2%. The method is inexpensive, versatile, simple, and sensitive.

Self-assembly behavior of tail-to-tail superstructure formed by mono-6-O-(4-carbamoylmethoxy-benzoyl)-β-cyclodextrin in solution and the solid state.

PubMed

Xu, Zhe; Chen, Xin; Liu, Jing; Yan, Dong-Qing; Diao, Chun-Hua; Guo, Min-Jie; Fan, Zhi

2014-07-01

A novel mono-modified β-cyclodextrin (β-CD) consisting of 4-carbamoylmethoxy-benzoyl unit at the primary side was synthesized and its self-assembly behavior was determined by X-ray crystallography and NMR spectroscopy. The crystal structure shows a 'Yin-Yang'-like packing mode, in which the modified β-CD exhibits a channel superstructure formed by a tail-to-tail dimer as the repeating motif with the substituted group embedded within the hydrophobic cavity of the facing β-CD. The geometry of the substituted group is determined by the inclusion of the cavity and is further stabilized by two intermolecular hydrogen bonds between the carbonyl O atom and phenyl group. Furthermore, NMR ROESY investigation indicates that the self-assembly behavior of the substituted group within the β-CD cavity is retained in aqueous solution, and the effective binding constant Ka was calculated to be 1330 M(-1) by means of (1)H NMR titration according to iterative determination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Efficacy of the addition of salicylic acid to clindamycin and benzoyl peroxide combination for acne vulgaris.

PubMed

Akarsu, Sevgi; Fetil, Emel; Yücel, Filiz; Gül, Eylem; Güneş, Ali T

2012-05-01

Clindamycin phosphate (CDP), benzoyl peroxide (BPO) and salicylic acid (SA) are known to be effective acne therapy agents depending on their anti-inflammatory and comedolytic properties. The purpose of this study was to investigate the efficacy and tolerability of the addition of SA treatment to CDP and BPO (SA and CDP + BPO) and compare it with CDP + BPO in patients with mild to moderate facial acne vulgaris. Forty-nine patients were enrolled in a 12 week prospective, single-blind, randomized, comparative clinical study. Efficacy was assessed by lesion counts, global improvement, quality of life index and measurements of skin barrier functions. Local side effects were also evaluated. Both combinations were effective in reducing total lesion (TL), inflammatory lesion (IL) and non-inflammatory lesion (NIL) counts. There were statistically significant differences between treatment groups for reductions in NIL counts beyond 2 weeks, IL counts and TL counts throughout the all study weeks, and global improvement scores evaluated by patients and investigator at the end of the study in favor of SA and CDP + BPO treatment when compared to CDP + BPO treatment. Both combinations significantly decreased stratum corneum hydration, although skin sebum values decreased with SA and CDP + BPO treatment. These combinations were also well tolerated except significantly higher frequency of mild to moderate transient dryness in patients applied SA and CDP + BPO. The addition of SA to CDP + BPO treatment demonstrated significantly better and faster results in terms of reductions in acne lesion counts and well tolerated except for higher frequency of mild to moderate transient dryness. © 2011 Japanese Dermatological Association.

Determination of rhenium content in molybdenite by ICP-MS after separation of the major matrix by solvent extraction with N-benzoyl-N-phenylhydroxalamine.

PubMed

Li, Jie; Zhong, Li-feng; Tu, Xiang-lin; Liang, Xi-rong; Xu, Ji-feng

2010-05-15

A simple and rapid analytical method for determining the concentration of rhenium in molybdenite for Re-Os dating was developed. The method used isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS) after the removal of major matrix elements (e.g., Mo, Fe, and W) from Re by solvent extraction with N-benzoyl-N-phenylhydroxylamine (BPHA) in chloroform solution. The effect on extraction efficiency of parameters such as pH (HCl concentration), BPHA concentration, and extraction time were also assessed. Under the optimal experimental conditions, the validity of the separation method was accessed by measuring (187)Re/(185)Re values for a molybdenite reference material (JDC). The obtained values were in good agreement with previously measured values of the Re standard. The proposed method was applied to replicate Re-Os dating of JDC and seven samples of molybdenite from the Yuanzhuding large Cu-Mo porphyry deposit. The results demonstrate good precision and accuracy for the proposed method. The advantages of the method (i.e., simplicity, efficiency, short analysis time, and low cost) make it suitable for routine analysis.

Quantitation of polyamines in cultured cells and tissue homogenates by reversed-phase high-performance liquid chromatography of their benzoyl derivatives.

PubMed

Verkoelen, C F; Romijn, J C; Schroeder, F H; van Schalkwijk, W P; Splinter, T A

1988-04-08

A rapid and simple method, originally described by Redmond and Tseng [J. Chromatogr., 170 (1979) 479] was applied to the analysis of di- and polyamines in cultured human tumour cells and human tumour xenografts. Optimization of the procedures and evaluation of the characteristic features of the assay are described. The (modified) procedure employs precolumn derivatization with benzoyl chloride, extraction of the derivatives by chloroform, separation by reversed-phase high-performance liquid chromatography under isocratic conditions and detection by ultraviolet absorbance measurement at 229 nm. The complete analysis was accomplished within 10 min per sample. The detection limit was ca. 1 pmol. The intra- and inter-assay coefficients of variation were 2.5-4.4% and 3.4-13.1%, respectively. The presence of well known inhibitors of polyamine biosynthesis, such as DL-alpha-difluoromethylornithine and methylglyoxal bis(guanylhydrazone), did not interfere with the assay, and disturbance by cyclohexylamine could be avoided by changing the polarity of the mobile phase. The method proved to be very suitable because it is rapid, simple, requires a minimum of sample pretreatment, and still provides sufficient sensitivity to quantitate polyamines in relatively small amounts of cells (10(5) cells) or tumour tissues (less than 1 mg), even after treatment with inhibitors of polyamine biosynthesis.

[Toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (4). 6-month repeated dose intravenous toxicity study in rats with 1-month recovery test].

PubMed

Yamaguchi, K; Aze, Y; Shimizu, K; Shichino, Y; Oku, H; Mori, H; Shinomiya, K; Ueda, H; Suzuki, Y; Oida, H; Nishibata, K; Tanaka, M; Yanagizawa, Y; Nanba, T; Nishiyama, K; Yonezawa, H; Fujita, T

1998-07-01

A 6-month repeated dose toxicity study with 1-month recovery test of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, was conducted in Sprague-Dawley (SD) rats. The rats of both sexes were administered ONO-5046.Na intravenously at a daily dose of 0 (vehicle control), 18.75, 37.5 or 75 mg/kg. ONO-5046.Na did not affect clinical signs, body weight, food consumption, opthalmology, urinalysis, hematology, blood chemistry, organ weight, necropsy or histopathology at any dose. These results indicate that the NOAEL of ONO-5046.Na in rats is 75 mg/kg/day for both sexes in this study.

Periodontal disease activity measured by the benzoyl-DL-arginine-naphthylamide test is associated with preterm births.

PubMed

Chan, Hui-Chen; Wu, Chen-Tsai; Welch, Kathleen B; Loesche, Walter J

2010-07-01

Infection is a risk factor for preterm birth. This study was conducted in the field and addressed the link between periodontal pathogens measured with the benzoyl-DL-arginine-naphthylamide (BANA) test and preterm birth. This prospective study was performed in Changhua, Taiwan. Periodontal examinations included the plaque index, papillary bleeding scores, and measurement of the BANA enzyme in plaque samples at the second and third trimesters. Independent variables included maternal demographic characteristics, previous pregnancy histories, risk factors, plaque and gingivitis scores, and current pregnancy outcomes. There were 19 (7%) preterm deliveries among the 268 subjects. A history of a previous preterm birth and low birth weight, frequency of prenatal visits, preterm uterine contractions, antepartum hemorrhages, placenta previae, and preterm premature rupture of membranes were significantly related to preterm birth (P = 0.035, 0.027, <0.001, 0.025, 0.006, 0.014, and <0.001, respectively). Maternal weight gain was higher with a normal term delivery (P = 0.003). Multivariable logistic regression analyses showed that the number of BANA-infected sites in the third trimester (odds ratio [OR]: 5.89; 95% confidence interval [CI]: 1.5 to 31.6), maternal weight gain (OR: 0.78; 95% CI: 0.65 to 0.91), antepartum hemorrhages (OR: 10.0; 95% CI: 2.2 to 46.9), and preterm premature rupture of membranes (OR: 12.6; 95% CI: 3.97 to 42.71) had significant influences on preterm-birth outcomes. BANA-positive plaque in the third trimester was associated with preterm births after controlling for other risk factors. The BANA test can be used to screen pregnant women at chairside and/or bedside to apply suitable intervention tactics.

Synthesis, spectral characterization, thermal behaviour, antibacterial activity and DFT calculation on N‧-[bis(methylsulfanyl) methylene]-2-hydroxybenzohydrazide and N‧-(4-methoxy benzoyl)-hydrazinecarbodithioic acid ethyl ester

NASA Astrophysics Data System (ADS)

Bharty, M. K.; Dani, R. K.; Kushawaha, S. K.; Prakash, Om; Singh, Ranjan K.; Sharma, V. K.; Kharwar, R. N.; Singh, N. K.

2015-06-01

Two new compounds N‧-[bis(methylsulfanyl) methylene]-2-hydroxybenzohydrazide {Hbmshb (1)} and N‧-(4-methoxy benzoyl)-hydrazinecarbodithioic acid ethyl ester {H2mbhce (2)} have been synthesized and characterized with the aid of elemental analyses, IR, NMR and single crystal X-ray diffraction data. Compounds 1 and 2 crystallize in orthorhombic and monoclinic systems with space group Pna21 and P21/n, respectively. Inter and intra molecular hydrogen bonding link two molecules and provide linear chain structure. In addition to this, compound 2 is stabilized by CH⋯π and NH⋯π interactions. Molecular geometry from X-ray analysis, geometry optimization, charge distribution, bond analysis, frontier molecular orbital (FMO) analysis and non-linear optical (NLO) effects have been performed using the density functional theory (DFT) with the B3LYP functional. The bioefficacy of compounds has been examined against the growth of bacteria to evaluate their anti-microbial potential. Compounds 1 and 2 are thermally stable and show NLO behaviour better than the urea crystal.

Vibrational spectroscopy investigation using ab initio and density functional theory analysis on the structure of 3-(6-benzoyl-2-oxobenzo[ d]oxazol-3(2 H)-yl)propanoic acid

NASA Astrophysics Data System (ADS)

Arslan, Hakan; Algül, Öztekin; Önkol, Tijen

2008-08-01

The molecular structure, vibrational frequencies and infrared intensities of the 3-(6-benzoyl-2-oxobenzo[ d]oxazol-3(2 H)-yl)propanoic acid were calculated by the HF and DFT methods using 6-31G(d) basis set. The FT-infrared spectra have been measured for the title compound in the solid state. We obtained 11 stable conformers for the title compound, however the Conformer 1 is approximately 3.88 kcal/mol more stable than the Conformer 11. The comparison of the theoretical and experimental geometry of the title compound shows that the X-ray parameters fairly well reproduce the geometry of the Conformer 1. The harmonic vibrations computed of this compound by the B3LYP/6-31G(d) method are in a good agreement with the observed IR spectral data. Theoretical vibrational spectra of the title compound were interpreted by means of PEDs using VEDA 4 program.

Effect of N-benzoyl-D-phenylalanine on streptozotocin-induced changes in the lipid and lipoprotein profile in rats.

PubMed

Ashokkumar, N; Pari, L; Manimekalai, A; Selvaraju, K

2005-03-01

The effect of N-benzoyl-D-phenylalanine (NBDP) and metformin combination treatment on circulatory lipids, lipoproteins and lipid peroxidation markers were studied in neonatal streptozotocin (nSTZ) non-insulin dependent diabetic rats. Non-insulin dependent diabetes mellitus (NIDDM) was induced by a single dose injection of streptozotocin (100 mg kg(-1), i. p.) to two-day-old rats. After 10-12 weeks, rats weighing above 150 g were selected for screening for the NIDDM model. The rats were checked for fasting blood glucose levels to confirm the status of NIDDM. NBDP (50,100 or 200 mg kg(-1) ) was administered orally for six weeks to the confirmed diabetic rats (to evaluate the effective dose). The levels of serum lipids and lipid peroxidation markers were significantly increased, whilst the activity of glucose-6-phosphate dehydrogenase was significantly decreased in nSTZ diabetic rats. NBDP and metformin were able to restore the altered serum lipids, lipoproteins, lipid peroxidation marker levels and glucose-6-phosphate dehydrogenase activity to almost control levels. The results showed the antihyperlipidaemic properties of NBDP and metformin in addition to its antidiabetic action. Combination treatment was more effective then either drug alone. The results indicated that the coadministration of NBDP with metformin to nSTZ diabetic rats normalized blood glucose and caused marked improvement in altered serum lipids, lipoproteins and lipid peroxidation markers during diabetes. The data indicated that NBDP represented an effective antihyperglycaemic and antihyperlipidaemic adjunct for the treatment of diabetes, and may be a potential source of new orally active agents for future therapy.

In vitro antimicrobial activity of benzoyl peroxide against Propionibacterium acnes assessed by a novel susceptibility testing method.

PubMed

Okamoto, Kazuaki; Ikeda, Fumiaki; Kanayama, Shoji; Nakajima, Akiko; Matsumoto, Tatsumi; Ishii, Ritsuko; Umehara, Masatoshi; Gotoh, Naomasa; Hayashi, Naoki; Iyoda, Takako; Matsuzaki, Kaoru; Matsumoto, Satoru; Kawashima, Makoto

2016-06-01

Benzoyl peroxide (BPO), a therapeutic agent for acne vulgaris, was assessed for in vitro antimicrobial activity against Propionibacterium acnes using a novel broth microdilution testing that improved BPO solubility. We searched for a suitable culture medium to measure the minimum inhibitory concentration (MIC) of BPO against P. acnes and finally found the Gifu anaerobic medium (GAM) broth supplemented with 0.1(v/v)% glycerol and 2(v/v)% Tween 80, in which BPO dissolved up to 1250 μg/mL and P. acnes grew well. The MICs and minimum bactericidal concentrations (MBCs) of BPO against 44 clinical isolates of P. acnes collected from Japanese patients with acne vulgaris were determined by our testing method using the supplemented GAM broth. The MICs of BPO were 128 or 256 μg/mL against all isolates of P. acnes regardless of susceptibility to nadifloxacin or clindamycin. The MBCs of BPO were also 128 or 256 μg/mL against the same isolates. Moreover, BPO at the MIC showed a rapid bactericidal activity against P. acnes ATCC11827 in time-kill assay. In conclusion, we could develop a novel assay for the MIC and MBC determinations of BPO against P. acnes, which is reliable and reproducible as a broth microdilution testing and the present results suggest that BPO has a potent bactericidal activity against P. acnes. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Evaluation of the efficacy, tolerability, and safety of an over-the-counter acne regimen containing benzoyl peroxide and salicylic acid in subjects with acne.

PubMed

Kircik, Leon H; Gwazdauskas, Jennifer; Butners, Victoria; Eastern, Joseph; Green, Lawrence J

2013-03-01

Benzoyl peroxide (BPO) is a widely used over-the-counter (OTC) topical acne treatment often used in combination with salicylic acid (SA) to achieve better comedone control than that achieved with BPO alone. MaxClarity™ is an OTC acne treatment system comprising BPO and SA in an aqueous foam delivery vehicle, VersaFoam AF™. This paper describes 2 open-label, single-arm studies conducted to assess the efficacy, safety, tolerability, and patient preference of MaxClarity in the treatment of mild, moderate, and severe acne. Subjects applied MaxClarity twice daily for 8 weeks in study 402 and for 12 weeks in study 405. Reductions in all lesion types were seen throughout both studies. At week 8 (study 402), there was a mean reduction from baseline of -56.9 ± 32.7% in total lesions in subjects with mild, moderate, or severe acne. At week 12 (study 405), there was a reduction from baseline of -61.6 ± 22.0% in total lesions in subjects with moderate or severe acne. Overall, both studies demonstrated that MaxClarity is a generally well tolerated and effective treatment for mild, moderate, and severe acne.

Effects of tolbutamide and N-benzoyl-D-phenylalanine (NBDP) on the regulation of [Ca2+]i oscillations in mouse pancreatic islets.

PubMed

Lenzen, S; Peckmann, T

2001-10-01

The sulfonylurea derivative, tolbutamide, and the phenylalanine derivative, N-benzoyl-D-phenylalanine (NBDP), both of which stimulate insulin secretion through interaction with the sulfonylurea receptor (SUR1), were studied for their ability to increase the [Ca(2+)](i) and to interact with the glucose-induced slow large amplitude [Ca(2+)](i) oscillations in isolated mouse pancreatic islets. Tolbutamide as well as NBDP induced [Ca(2+)](i) oscillations of extremely slow frequency. Both compounds also lowered the threshold for the glucose-induced slow large amplitude [Ca(2+)](i) oscillations and significantly reduced their frequency in intact islets as well as in single pancreatic beta cells. These [Ca(2+)](i) oscillations apparently require a glucokinase-mediated glycolytic flux. This conclusion is supported by the observations that KIC, a mitochondrial fuel, cannot replace glucose in this synergism and that mannoheptulose, an inhibitor of glucokinase and glucose-induced insulin secretion, abolishes these slow [Ca(2+)](i) oscillations. In conclusion, these compounds potentiate the effect of glucose. This additive effect is the likely result of a synergistic closing action upon the ATP-sensitive K(+) (K(ATP)) channel, mediated in the case of glucose through an action upon the channel protein itself of ATP generated in glucose catabolism and in the case of tolbutamide and NBDP upon the sulfonylurea receptor (SUR1) associated with this channel.

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

NASA Astrophysics Data System (ADS)

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

2016-01-01

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2‧-bipy)(H2O)]n (1), [Cd(bzgluO)(2,4‧-bipy)2(H2O)·3H2O]n (2), [Cd(bzgluO)(phen)·H2O]n (3), [Cd(bzgluO)(4,4‧-bipy)(H2O)]n (4), [Cd(bzgluO)(bpp)(H2O)·2H2O]n (5) were synthesized (2,2‧-bipy=2,2‧-bipyridine, 2,4‧-bipy=2,4‧-bipyridine, phen=1,10-phenanthroline, 4,4‧-bipy=4,4‧-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1-2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π-π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π-π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H2bzgluO. Luminescent properties of 1-5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated.

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.

A double-blind, randomized, bilateral comparison of skin irritancy following application of the combination acne products clindamycin/tretinoin and benzoyl peroxide/adapalene.

PubMed

Goreshi, Renato; Samrao, Aman; Ehst, Benjamin D

2012-12-01

The use of topical medications for acne vulgaris is often limited by their irritant properties. Newer combination preparations are available and offer convenience, but irritant potential may still be a hindrance, perhaps more so with the combination of 2 agents. Few studies have compared these formulations directly for tolerability. We sought to compare the tolerability of 2 combination topical acne products, clindamycin 1.2%-tretinoin 0.025% (CLIN/RA) gel and benzoyl peroxide 2.5%-adapalene 0.1% (BPO/ADA) gel. CLIN/RA and BPO/ADA were applied daily to opposite sides of a subject's face for 21 days in a double-blinded fashion. Investigators' Global Assessments and study subject self-assessments of burning/stinging, itching, erythema, and dryness/scaling were collected. Transepidermal water loss (TEWL) was also measured as an objective measure of skin irritation. A mixed model analysis and repeated-measures analysis of variance were used to compare outcomes for both acne formulations. CLIN/RA produced significantly less burning/stinging than BPO/ADA (P<.001) as well as significantly less pruritus than BPO/ ADA (P<.001). BPO/ADA caused significantly more TEWL than CLIN/RA (P=.005). There was no significant difference in the amount of erythema or the amount of dryness/scaling caused by either formulation. CLIN/RA produced significantly less skin irritancy and TEWL than BPO/ADA.

Insight into the theoretical and experimental studies of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone N(4)-methyl-N(4)- phenylthiosemicarbazone - A potential NLO material

NASA Astrophysics Data System (ADS)

Sangeetha, K. G.; Aravindakshan, K. K.; Safna Hussan, K. P.

2017-12-01

The synthesis, geometrical parameters, spectroscopic studies, optimised molecular structure, vibrational analysis, Mullikan population analysis, MEP, NBO, frontier molecular orbitals and NLO effects of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone N-(4)-methyl-N-(4)-phenylthiosemicarbazone, C25H23N5OS (L1) have been communicated in this paper. A combined experimental and theoretical approach was used to explore the structure and properties of the compound. For computational studies, Gaussian 09 program was used. Starting geometry of molecule was taken from X-ray refinement data and has been optimized by using DFT (B3LYP) method with the 6-31+G (d, p) basis sets. NBO analysis gave insight into the strongly delocalized structure, responsible for the nonlinearity and hence the stability of the molecule. Frontier molecular orbitals have been defined to forecast the global reactivity descriptors of L1. The computed first-order hyperpolarizability (β) of the compound is 2 times higher than that of urea and this account for its nonlinear optical property. Simultaneously, a molecular docking study of the compound was performed using GLIDE Program. For this, three biological enzymes, histone deacetylase, ribonucleotide reductase and DNA methyl transferase, were selected as receptor molecules.

Heterologous desensitization of muscarinic receptors by P2Z purinoceptors in rat parotid acinar cells.

PubMed

Fukushi, Y

1999-01-01

We studied the heterologous desensitization of muscarinic receptors by ATP in fura-2-loaded rat parotid acinar cells. Exposure to ATP or 3'-o-(4-benzoyl) benzoyl-ATP shortened the duration and decreased the magnitude of acetylcholine-induced Ca2+ release from intracellular Ca2+ stores in a dose-dependent manner. The shortening was observed only in an early stage of desensitization (within 20 s), whereas the decrease in the magnitude of the response was dependent upon the time the cells were exposed to the nucleotides. Atropine induced a profound shortening during the progressive decrease in the magnitude of acetylcholine-induced Ca2+ release. 3'-o-(4-Benzoyl) benzoyl-ATP did not induce an increase in the cytosolic Ca2+ concentration when the cells were incubated in the Ca2+- and Na+-free medium, but it did induce a strong desensitization of muscarinic receptors. The specific protein kinase C inhibitor bisindoylmaleimide resensitized the 3'-o-(4-benzoyl) benzoyl-ATP-treated muscarinic receptors. Phorbol 12-myristate 13-acetate potentiated the desensitization of muscarinic receptors. Ceramides that prevent the activation of phospholipase D resensitized the 3'-o-(4-benzoyl) benzoyl-ATP-treated muscarinic receptors. These results suggest that ATP, acting through P2Z purinoceptor-mediated phospholipase D, may produce a Ca2+-independent protein kinase C. Heterologous desensitization of muscarinic receptors by protein kinase C may shorten the duration and decrease the magnitude of acetylcholine-induced Ca2+ release.

Systemic exposure to benzoic acid and hippuric acid following topical application of clindamycin 1%/benzoyl peroxide 3% fixed-dose combination gel in Japanese patients with acne vulgaris.

PubMed

Ino, Hiroko; Takahashi, Naoki; Saenz, Alessandra Alio; Wakamatsu, Akira; Hashimoto, Hirofumi; Nakahara, Norie; Hasegawa, Setsuo

2015-01-01

Clindamycin 1%/benzoyl peroxide 3% fixed-dose combination gel (CLDM/BPO3%) is a topical product for the treatment of acne vulgaris. In this study, plasma and urine concentrations of benzoic acid (BA) and hippuric acid (HA) were analyzed to estimate the pharmacokinetics (PK) of BPO after application of CLDM/BPO3% twice-daily for 7 days in Japanese patients with acne vulgaris. Seven-day repeated application of CLDM/BPO3% appears to be safe in this patient population. Concentrations of plasma and urine BA were below the limit of quantification before and after repeated application in most of the 12 adult male patients. Mean difference in Cmax and AUC0-last for plasma HA indicated increased exposures after repeated application, but with wide 90% confidence intervals. Mean Ae0-12 for urine HA was similar before and after repeated application. Repeated application of CLDM/BPO3% is thus unlikely to result in accumulation of BA and HA. The study suggests negligible systemic exposure to BPO metabolites from CLDM/BPO3% after 7-day repeated application in male patients with acne vulgaris. © 2014, The American College of Clinical Pharmacology.

Randomized tolerability analysis of clindamycin phosphate 1.2%-tretinoin 0.025% gel used with benzoyl peroxide wash 4% for acne vulgaris.

PubMed

Draelos, Zoe Diana; Potts, Aaron; Alió Saenz, Alessandra B

2010-12-01

The multiple etiologic factors involved in acne vulgaris make the use of several medications necessary to treat the condition. Use of a fixed combination of clindamycin phosphate 1.2% and tretinoin 0.025% in conjunction with a benzoyl peroxide (BPO) wash 4% targets several pathologic factors simultaneously and mitigates the potential for clindamycin-induced Propionibacterium acnes-resistant strains. New formulations may allow such regimens to be effectively used without overly reduced tolerability resulting from the irritation potential of tretinoin and BPO. This randomized, single-blind study investigated the local tolerability, irritation potential, and safety of an aqueous-based gel (clindamycin phosphate 7.2%-tretinoin 0.025% [CT gel]) when used in conjunction with a BPO wash 4% in participants with mild to moderate acne vulgaris. Participants applied the CT gel once daily in the evening for 4 weeks in conjunction with once-daily morning use of either BPO wash 4% or nonmedicated soap-free cleanser lotion (SFC). Local tolerability and irritation potential were assessed by participants and investigators using separate 6-point scales. The frequency and severity of dryness, scaling, erythema, burning/stinging, and itching increased during the first week of treatment in both treatment arms but decreased thereafter. Local tolerability reactions were slightly more frequent in the CT gel + BPO wash group versus the CT gel + SFC group at week 1 but were generally mild and improved within 1 to 2 weeks. In conclusion, therapy with CT gel + BPO wash appears safe and well-tolerated in participants with mild to moderate acne vulgaris.

Tretinoin gel microsphere pump 0.04% plus 5% benzoyl peroxide wash for treatment of acne vulgaris: morning/morning regimen is as effective and safe as morning/evening regimen.

PubMed

Pariser, David; Bucko, Alicia; Fried, Richard; Jarratt, Michael T; Kempers, Steven; Kircik, Leon; Lucky, Anne W; Rafal, Elyse; Rendon, Marta; Weiss, Jonathan; Wilson, David C; Rossi, Ana Beatris; Ramaswamy, Ratna; Nighland, Marge

2010-07-01

Topical tretinoin and benzoyl peroxide (BPO) are often prescribed in combination for the treatment of acne vulgaris; however, these products have not traditionally been administered simultaneously because of the potential for tretinoin degradation by BPO as well as the instability of tretinoin in daylight. The primary objective of this randomized, investigator-blinded, 12-week, phase 4 trial was to determine non-inferiority of a once-daily morning combination regimen of 5% BPO wash + tretinoin gel microsphere (TGM) 0.04% pump versus a sequential regimen (BPO in the morning/TGM in the evening) in patients > or = 12 years old with moderate facial acne vulgaris. The primary efficacy endpoint was the change from baseline in total acne lesions; the primary safety endpoint was the change in cutaneous irritation scores. The 247 participants (mean age: 18.5 years) were randomized to either the morning/morning regimen (n = 123) or the morning/evening regimen (n = 124). The morning/morning regimen was determined to be non-inferior to the morning/evening regimen in reduction of total acne lesions. The tolerability of both regimens was comparable. The morning/morning regimen is a safe and effective treatment option for patients with moderate acne vulgaris.

[Toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (1). Single-dose intravenous toxicity studies in rats and dogs].

PubMed

Yanagi, H; Yamaguchi, K; Shimizu, K; Shichino, Y; Nishiyama, K; Mori, H; Shinomiya, K; Ueda, H; Suzuki, Y; Yonezawa, H; Fujita, T

1998-07-01

Single-dose toxicity studies of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, were conducted in Sprague-Dawley (SD) rats and beagle dogs. The rats of both sexes were administered ONO-5046.Na intravenously at a single dose of 150, 300 or 450 mg/kg. The male dogs were also given ONO-5046.Na at a single dose of 75 or 150 mg/kg. In the rat study, hypoactivity, bradypnea and paleness of limbs and pinna were observed at doses of 300 mg/kg and above. In particular, one of six female rats in the 450 mg/kg group showed clonic convulsion and died. In surviving animals, those signs disappeared within 3 hr after administration. No effect on body weight gain was seen in either group. Necropsy findings showed a slight foamy fluid in the bronchus, hemorrhage at the right knee joint muscle, tendon and lung in a dead animal. In the dog study, no effects on clinical signs, body weight, food consumption and blood biochemistry were seen in any animals of the 75 and 150 mg/kg groups. It is concluded that the approximate lethal doses are 450 mg/kg in rats and 150 mg/kg and above in dogs.

Acne

MedlinePlus

... a cream or lotion with benzoyl peroxide, resorcinol, salicylic acid, or sulfur. Benzoyl peroxide works to reduce oil made by the glands. Resorcinol, salicylic acid, and sulfur help breakdown whiteheads and blackheads. If ...

Acne -- self-care

MedlinePlus

... It may help to use a wash with salicylic acid or benzoyl if your skin is oily and ... products may contain benzoyl peroxide, sulfur, resorcinol, or salicylic acid. They work by killing bacteria, drying up skin ...

Acne

MedlinePlus

... may contain benzoyl peroxide, sulfur, resorcinol, adapalene, or salicylic acid. They work by killing bacteria, drying up skin ... Prescription formulas of benzoyl peroxide, sulfur, resorcinol, or salicylic acid Topical azelaic acid For women whose acne is ...

Topical Acne Treatments and Pregnancy

MedlinePlus

... are benzoyl peroxide, azelaic acid, glycolic acid, and salicylic acid. Prescription acne medications include tretinoin, adapalene, dapsone, and ... ACOG) recommends topical benzoyl peroxide, azelaic acid, topical salicylic acid and glycolic acid for treatment of acne in ...

Synthesis and photoluminescence properties of silver(I) complexes based on N-benzoyl-L-glutamic acid and N-donor ligands with different flexibility

NASA Astrophysics Data System (ADS)

Yan, Ming-Jie; Feng, Qi; Song, Hui-Hua

2016-05-01

By changing the N-donor ancillary ligand, three novel silver (I) complexes {[Ag(HbzgluO) (4,4‧-bipy)]·H2O}n (1), {[Ag2(HbzgluO)2 (bpe)2]·2H2O}n (2) and {[Ag(HbzgluO)(bpp)]·2H2O}n (3) (H2bzgluO = N-benzoyl-L-glutamic acid, 4,4‧-bipy = 4,4ˊ-bipyridine, bpe = 1,2-di(4-pyridyl)ethane, bpp = 1,3-di(4-pyridyl)propane) were synthesized. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). In this study, the N-donor ligands are changed from rigidity (4,4‧-bipy), quasi-flexibility (bpe) to flexibility (bpp), the structures of complexes also change. Complex 1 features a 1D chain structure which is further linked together to construct a 2D supramolecular structure through hydrogen bonds. Complex 2 is a 1D double-chains configuration which eventually forms a 3D supramolecular network via hydrogen bonding interactions. Whereas, complex 3 exhibits a 2D pleated grid structure which is linked by hydrogen bonding interactions into a 3D supramolecular network. The present observations demonstrate that the modulation of coordination polymers with different structures can accomplish by changing the spacer length of N-donor ligands. In addition, the solid-state circular dichroism (CD) spectra indicated that compound 2 exhibited negative cotton effect which originated from the chiral ligands H2bzgluO and the solid-state fluorescence spectra of the three complexes demonstrated the auxiliary ligands have influence on the photoluminescence properties of the complexes.

Formulation and evaluation of a topical niosomal gel containing a combination of benzoyl peroxide and tretinoin for antiacne activity.

PubMed

Gupta, Ankush; Singh, Sima; Kotla, Niranjan G; Webster, Thomas J

2015-01-01

A skin disease, like acne, is very common and normally happens to everyone at least once in their lifetime. The structure of the stratum corneum is often compared with a brick wall, with corneocytes surrounded by the mortar of the intercellular lipid lamellae. One of the best options for successful drug delivery to the affected area of skin is the use of elastic vesicles (niosomes) which can be transported through the skin through channel-like structures. In this study, a combination of tretinoin (keratolytic agent) and benzoyl peroxide (BPO) (a potent antibacterial) was given by using niosomes as promising carriers for the effective treatment of acne by acting on a pathogenic site. In this section, niosomal gel formulation encapsulated drugs have been evaluated for in vitro, ex vivo, and in vivo, for their predetermined characteristics; and finally the stability of the niosome gel was tested at different temperature conditions for understanding of the storage conditions required for maintaining the quality of formulation attributes. The prepared niosome was found to be in the range of 531 nm with a zeta potential of -43 mV; the entrapment efficiencies of tretinoin (TRA) and BPO niosomes were found to be 96.25%±0.56% and 98.75%±1.25%, respectively. The permeated amount of TRA and BPO from the niosomal gel after 24 hours was calculated as 6.25±0.14 μg/cm(2) and 5.04±0.014 μg/cm(2), respectively. A comparative drug retention study in Wistar rat skin using cream, an alcoholic solution, and a niosomal gel showed 11.54 μg, 2.68 μg, and 15.54 μg amounts of TRA and 68.85 μg, 59.98 μg, and 143.78 μg amounts of BPO were retained in the layers of skin, respectively. In vivo studies of the niosomal gel and antiacne cream of TRA and BPO showed that the niosomal gel was more efficacious than the antiacne cream because niosomal gels with a 4.16-fold lower dose of BPO provided the same therapeutic index at targeted sites in comparison to the antiacne cream.

Formulation and evaluation of a topical niosomal gel containing a combination of benzoyl peroxide and tretinoin for antiacne activity

PubMed Central

Gupta, Ankush; Singh, Sima; Kotla, Niranjan G; Webster, Thomas J

2015-01-01

A skin disease, like acne, is very common and normally happens to everyone at least once in their lifetime. The structure of the stratum corneum is often compared with a brick wall, with corneocytes surrounded by the mortar of the intercellular lipid lamellae. One of the best options for successful drug delivery to the affected area of skin is the use of elastic vesicles (niosomes) which can be transported through the skin through channel-like structures. In this study, a combination of tretinoin (keratolytic agent) and benzoyl peroxide (BPO) (a potent antibacterial) was given by using niosomes as promising carriers for the effective treatment of acne by acting on a pathogenic site. In this section, niosomal gel formulation encapsulated drugs have been evaluated for in vitro, ex vivo, and in vivo, for their predetermined characteristics; and finally the stability of the niosome gel was tested at different temperature conditions for understanding of the storage conditions required for maintaining the quality of formulation attributes. The prepared niosome was found to be in the range of 531 nm with a zeta potential of −43 mV; the entrapment efficiencies of tretinoin (TRA) and BPO niosomes were found to be 96.25%±0.56% and 98.75%±1.25%, respectively. The permeated amount of TRA and BPO from the niosomal gel after 24 hours was calculated as 6.25±0.14 μg/cm2 and 5.04±0.014 μg/cm2, respectively. A comparative drug retention study in Wistar rat skin using cream, an alcoholic solution, and a niosomal gel showed 11.54 μg, 2.68 μg, and 15.54 μg amounts of TRA and 68.85 μg, 59.98 μg, and 143.78 μg amounts of BPO were retained in the layers of skin, respectively. In vivo studies of the niosomal gel and antiacne cream of TRA and BPO showed that the niosomal gel was more efficacious than the antiacne cream because niosomal gels with a 4.16-fold lower dose of BPO provided the same therapeutic index at targeted sites in comparison to the antiacne cream. PMID

High-performance liquid chromatography with peroxyoxalate chemiluminescence detection of bisphenol A migrated from polycarbonate baby bottles using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a label.

PubMed

Sun, Y; Wada, M; Al-Dirbashi, O; Kuroda, N; Nakazawa, H; Nakashima, K

2000-11-10

A highly sensitive and selective high-performance liquid chromatographic method with peroxyoxalate chemiluminescence detection for the determination of bisphenol A at sub-ppb levels is described. Bisphenol A was derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride and the excess unreacted reagent was removed by a simple solid-phase extraction procedure with recoveries of approximately 60%. The separation was carried out isocratically on an ODS column and the derivatized bisphenol A was detected by peroxyoxalate chemiluminescence. A mixture of bis[2-(3,6,9-trioxadecanyloxycarbonyl)-4-nitrophenyl]oxalate (0.6 mM) and hydrogen peroxide (25.0 mM) dissolved in acetonitrile was used as a chemiluminescence reagent solution with a mixture of imidazole-HNO3 buffer (40.0 mM, pH 7.0): acetonitrile (17:83, v/v) as a mobile phase. The linear standard curve was obtained over the range from 0.57 (2.5) to 22.8 (100) ppb (nM) (r=0.996) with a detection limit of 0.38 ppb (2.8 fmol on column) at a signal-to-noise ratio of 3. The method was successfully applied to the determination of bisphenol A in hot water in contact with commercially available baby bottle samples.

High performance liquid chromatography with UV detection for the simultaneous determination of sympathomimetic amines using 4-(4,5-diphenyl-1H-imidazole-2-yl)benzoyl chloride as a label.

PubMed

Kaddoumi, A; Kubota, A; Nakashima, M N; Takahashi, M; Nakashima, K

2001-10-01

A high performance liquid chromatographic method has been developed for the simultaneous determination of (+/-) fenfluramine (Fen) and phentermine (Phen) in addition to three other sympathomimetic amines-ephedrine (E), norephedrine (NE) and 2-phenylethylamine (2-PEA), using cyclohexylamine (CX) as an internal standard in plasma. The compounds were derivatized with 4-(4,5-diphenyl-1H-imidazole-2-yl)benzoyl chloride (DIB-Cl) to give the DIB-derivatives. The derivatives were then separated using an isocratic HPLC system with UV detection. The limits of detection for Fen, Phen, E, NE and 2-PEA in plasma ranged from 0.32 to 22.9 pmol on column at a signal-to-noise ratio of 3. The recoveries following alkaline extraction from plasma samples of known concentrations were found to be more than 94% for the studied compounds. This method might be useful for the screening of the studied sympathomimetic amines in human plasma samples in forensic as well as toxicological studies. Furthermore, the developed method was modified for the simultaneous determination of Fen and Phen in human and rat plasma using fluoxetine as an internal standard. The methods are reproducible and precise. Finally, the two drugs were administered intraperitoneally to rats in combination, and their plasma levels over the investigated time course were successfully determined. Copyright 2001 John Wiley & Sons, Ltd.

Metal complexes of the nanosized ligand N-benzoyl-N‧-(p-amino phenyl) thiourea: Synthesis, characterization, antimicrobial activity and the metal uptake capacity of its ligating resin

NASA Astrophysics Data System (ADS)

Elhusseiny, Amel F.; Eldissouky, Ali; Al-Hamza, Ahmed M.; Hassan, Hammed H. A. M.

2015-11-01

The new nanosized N-benzoyl-N‧-(p-amino phenyl) thiourea ligand H2L was synthesized by nanoprecipitation method. The [Cu (H2L)2 Cl]·2H2O, [Zn (H2L)2(OAc)2], [Cd (H2L)2Cl2] and [Hg (H2L)2Cl2] complexes were synthesized and characterized by various physicochemical methods. Results revealed that the ligand act as hypodentate and bonded to the metal ion via the sulfur atom forming mononuclear non-electrolyte diamagnetic complex. Magnetic moment results indicated a reduction of Cu (II) to Cu (I) during the coordination process. Thermal studies demonstrated variable stabilities of the complexes and [Zn (H2L)2(OAc)2] exhibited the highest thermal stability while [Hg (H2L)2Cl2] was volatile. The prepared compounds were screened against different pathogenic microorganisms. The ligand performed high antibacterial activity against certain bacterial strain compared to its complexes, and the standard bacteriocide in use. The ligand was successfully immobilized on modified Amberlite XAD-16 forming the hypodentate ligating resin PS-SO2-H2L. The new resin was characterized and the extent of metal adsorption reached maximum at pH 6.0 for Cu (II), Cd (II) and Ag (I), with an adsorption amount of 4.3, 4.0 and 3.7 mmol g-1 respectively. The nanosized H2L represents a new category of promising adsorbent that would have a practical impact on biological and water treatment applications.

Scoparic acid A, a beta-glucuronidase inhibitor from Scoparia dulcis.

PubMed

Hayashi, T; Kawasaki, M; Okamura, K; Tamada, Y; Morita, N; Tezuka, Y; Kikuchi, T; Miwa, Y; Taga, T

1992-12-01

The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor.

Twelve-week, multicenter, placebo-controlled, randomized, double-blind, parallel-group, comparative phase II/III study of benzoyl peroxide gel in patients with acne vulgaris: A secondary publication.

PubMed

Kawashima, Makoto; Sato, Shinichi; Furukawa, Fukumi; Matsunaga, Kayoko; Akamatsu, Hirohiko; Igarashi, Atsuyuki; Tsunemi, Yuichiro; Hayashi, Nobukazu; Yamamoto, Yuki; Nagare, Toshitaka; Katsuramaki, Tsuneo

2017-07-01

A placebo-controlled, randomized, double-blind, parallel-group, comparative, multicenter study was conducted to investigate the efficacy and safety of benzoyl peroxide (BPO) gel, administrated once daily for 12 weeks to Japanese patients with acne vulgaris. Efficacy was evaluated by counting all inflammatory and non-inflammatory lesions. Safety was evaluated based on adverse events, local skin tolerability scores and laboratory test values. All 609 subjects were randomly assigned to receive the study products (2.5% and 5% BPO and placebo), and 607 subjects were included in the full analysis set, 544 in the per protocol set and 609 in the safety analyses. The median rates of reduction from baseline to the last evaluation of the inflammatory lesion counts, the primary end-point, in the 2.5% and 5% BPO groups were 72.7% and 75.0%, respectively, and were significantly higher than that in the placebo group (41.7%). No deaths or other serious adverse events were observed. The incidences of adverse events in the 2.5% and 5% BPO groups were 56.4% and 58.8%, respectively; a higher incidence than in the placebo group, but there was no obvious difference between the 2.5% and 5% BPO groups. All adverse events were mild or moderate in severity. Most adverse events did not lead to study product discontinuation. The results suggested that both 2.5% and 5% BPO are useful for the treatment of acne vulgaris. © 2017 The Authors. The Journal of Dermatology published by John Wiley & Sons Australia, Ltd.

Deformation and Thermal Properties of Energetic Materials.

DTIC Science & Technology

1980-12-01

have done some experiments in which they find that tetramethylammonium tribo- hydride (a free radical donor) causes increased reaction with ammonium ... nitrate . In order to test this hypothesis, mixtures of benzoyl peroxide and PETN were used in a series of TG experiments. Benzoyl peroxide is an...thec Lui~ycr;1 i that ;1 pol1 m\

Effect of N-benzoyl-D-phenylalanine and metformin on insulin receptors in neonatal streptozotocin-induced diabetic rats: studies on insulin binding to erythrocytes.

PubMed

Ashokkumar, N; Pari, L; Rao, Ch Appa

2006-07-01

In the present study, we focused on the insulin-receptor binding in circulating erythrocytes of N-benzoyl-D-phenylalanine (NBDP) and metformin in neonatal streptozotocin (nSTZ)-induced male Wistar rats. We measured blood levels of glucose and plasma insulin and the binding of insulin to cell-membrane ER receptors in NBDP and metformin-treated diabetic rats. The mean specific binding of insulin to ER was significantly lower in diabetic control rats (DC) (53.0 +/- 3.1%) than in NBDP (62.0 +/- 3.1%), metformin (66.0 +/- 3.3%) and NBDP and metformin combination-treated (72.0 +/- 4.2%) diabetic rats, resulting in a significant decrease in plasma insulin. Scatchard plot analysis demonstrated that the decrease in insulin binding was accounted for by a lower number of insulin receptor sites per cell in DC rats when compared with NBDP and metformin-treated rats. High-affinity (Kd1), low-affinity (Kd2), and kinetic analysis revealed an increase in the average receptor affinity in ER from NBDP and metformin-treated diabetic rats having NBDP 2.0 +/- 0.10 x 10(-10) M(-1) (Kd1); 12.0 +/- 0.85 x 10(-8) M(-1) (Kd2), Metformin 2.1 +/- 0.15 x 10(-10) M(-1) (Kd1); 15.0 +/- 0.80 x 10(-8) M(-1) (Kd2), NBDP and metformin 2.7 +/- 0.10 x 10(-10) M(-1) (Kd1); 20.0 +/- 1.2 x 10(-8) M(-1) (Kd2) compared with 0.9 +/- 0.06 x 10(-10) M(-1) (Kd1); 6.0 +/- 0.30 x 10(-8) M(-1) (Kd2) in DC rats. The results suggest an acute alteration in the number of insulin receptors on ER membranes in nSTZ induced diabetic control rats. Treatment with NBDP along with metformin significantly improved specific insulin binding, with receptor number and affinity binding reaching almost normal non-diabetic levels. The data presented here show that NBDP along with metformin increase total ER membrane insulin binding sites with a concomitant significant increase in plasma insulin.

Comparison of the benzoyl-DL-arginine-naphthylamide (BANA) test, DNA probes, and immunological reagents for ability to detect anaerobic periodontal infections due to Porphyromonas gingivalis, Treponema denticola, and Bacteroides forsythus.

PubMed Central

Loesche, W J; Lopatin, D E; Giordano, J; Alcoforado, G; Hujoel, P

1992-01-01

Most forms of periodontal disease are associated with the presence or overgrowth of anaerobic species that could include Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus among others. These three organisms are among the few cultivable plaque species that can hydrolyze the synthetic trypsin substrate benzoyl-DL-arginine-naphthylamide (BANA). In turn, BANA hydrolysis by the plaque can be associated with periodontal morbidity and with the presence of these three BANA-positive organisms in the plaque. In this investigation, the results of the BANA test, which simultaneously detects one or more of these organisms, were compared with the detection of these organisms by (i) highly specific antibodies to P. gingivalis, T. denticola, and B. forsythus; (ii) whole genomic DNA probes to P. gingivalis and T. denticola; and (iii) culturing or microscopic procedures. The BANA test, the DNA probes, and an enzyme-linked immunosorbent assay or an indirect immunofluorescence assay procedure exhibited high sensitivities, i.e., 90 ot 96%, and high accuracies, i.e., 83 to 92%, in their ability to detect combinations of these organisms in over 200 subgingival plaque samples taken from the most periodontally diseased sites in 67 patients. This indicated that if P. gingivalis, T. denticola, and B. forsythus are appropriate marker organisms for an anaerobic periodontal infection, then the three detection methods are equally accurate in their ability to diagnose this infection. The same statement could not be made for the culturing approach, where accuracies of 50 to 62% were observed. PMID:1311335

Microscopic progression in the free radical addition reaction: modeling, geometry, energy, and kinetics.

PubMed

Zhang, Yun; Huang, Hong; Liang, Zhiling; Liu, Houhe; Yi, Ling; Zhang, Jinhong; Zhang, Zhiqiang; Zhong, Cheng; Huang, Yugang; Ye, Guodong

2017-03-01

The free radical addition reaction is very important in UV curing. The benzoyl radical is the most commonly observed radical. In the addition process, the benzoyl radical adds to an acrylate monomer, forming a primary radical that has great value for subsequent research. In this article, a quantum chemical method was used to study the microscopic progression from the reactive complex to the saddle point. The reactions of three monomers (amylene, allyl methyl ether and methyl acrylate) with a benzoyl radical were evaluated in terms of geometry and energy. The results were also interpreted with an expanded version of the Polanyi rules and the interaction/deformation theory. The deformation energy of methyl acrylate was found to be the smallest, and the bond formation index showed that the transition state in the methyl acrylate system forms early, and can easily reach the saddle point. The activity of the monomer was ascertained by charge analysis and was further confirmed by the reaction rate. Mayer bond order curves depicted the constantly changing chemical bonds during formation and dissociation. Reduced density gradient analysis showed a weak interaction between the monomer and the benzoyl radical.

4D Interconnect Experimental Development

DTIC Science & Technology

1993-06-29

Polymerization of MMA Using Benzoyl Peroxide ..... .......... 6 2.1.2.3 Polymerization Using Benzoin ........ .................. 7 2.1.3 Adding the SHB...molecules.J6l This breakdown can be driven thermally (as in the case of benzoyl peroxide) or via UV illumination (as in the case of benzoin ). Once...taken is increased. 6 2.1.2.3 Polymerization Using Benzoin A commonly used alternative to the initiation being driven thermally is to use a photoini

Angiotensin-converting enzyme: I. New strategies for assay

PubMed Central

Ryan, James W.; Chung, Alfred; Ryan, Una S.

1980-01-01

The disposition of converting enzyme (kininase II) on the luminal surface of pulmonary endothelial cells is well established. Further, it is known that there is a net conversion of angiotensin I into angiotensin II as blood passes through the lungs. However, little is known about modulations of converting enzyme activity that may arise through, e.g., changes in the quality of inhalants, blood flow, or blood oxygenation. There are few data on the effects of lung disease. A major barrier to studies to examine for pathophysiologic modulations of converting enzyme is that of assay. The enzyme can be measured in terms of the rate of formation of angiotensin II from a known quantity of angiotensin I. However, both peptides are biologically active, and lungs contain other enzymes capable of degrading them. We have developed a series of radiolabeled, acylated tripeptides to improve our ability to examine for changes in the net converting enzyme of intact lungs. The enzyme, a dipeptidyl carboxypeptidase, is capable of removing C-terminal dipeptides from a variety of oligopeptides. We have prepared benzoyl-Gly-Gly-Gly (I), benzoyl-Pro-Phe-Arg (II), benzoyl-Gly-His-Leu (III), benzoyl-Phe-Ala-Pro (IV), and benzoyl-Phe-His-Leu (V), each containing a 3H-atom in the para position of the benzoyl moiety. Substrates I and III have been used previously in photometric assays of low sensitivity. II is the acylated C-terminal tripeptide of bradykinin, IV is an acylated tripeptide analog of BPP5a (

Nitrolysis of the CN Single Bond and Related Chemistry of Nitro and Nitroso Groups.

DTIC Science & Technology

1988-03-01

oxime of be 4,5-diphenyl-l-triphenylmethoxy-l,23- triazole (11). It was benzoyl cyanide (Scheme 6), for which radical intermediates hydrolysed by...S-Pnitroxide (a radical scavenger) or benzoyl peroxide (a radical *PhC CCN)- NO2 Ag PhCON--CPh suc)I I source). A partial extension of the overall...two anomethylenenitronate anion. (Attempts to prepare the pathways for fragmentation of the ester (3) (C,.H,0 N.O,): one ketenimine (15) by a

Enzymes involved in the anaerobic degradation of ortho-phthalate by the nitrate-reducing bacterium Azoarcus sp. strain PA01.

PubMed

Junghare, Madan; Spiteller, Dieter; Schink, Bernhard

2016-09-01

The pathway of anaerobic degradation of o-phthalate was studied in the nitrate-reducing bacterium Azoarcus sp. strain PA01. Differential two-dimensional protein gel profiling allowed the identification of specifically induced proteins in o-phthalate-grown compared to benzoate-grown cells. The genes encoding o-phthalate-induced proteins were found in a 9.9 kb gene cluster in the genome of Azoarcus sp. strain PA01. The o-phthalate-induced gene cluster codes for proteins homologous to a dicarboxylic acid transporter, putative CoA-transferases and a UbiD-like decarboxylase that were assigned to be specifically involved in the initial steps of anaerobic o-phthalate degradation. We propose that o-phthalate is first activated to o-phthalyl-CoA by a putative succinyl-CoA-dependent succinyl-CoA:o-phthalate CoA-transferase, and o-phthalyl-CoA is subsequently decarboxylated to benzoyl-CoA by a putative o-phthalyl-CoA decarboxylase. Results from in vitro enzyme assays with cell-free extracts of o-phthalate-grown cells demonstrated the formation of o-phthalyl-CoA from o-phthalate and succinyl-CoA as CoA donor, and its subsequent decarboxylation to benzoyl-CoA. The putative succinyl-CoA:o-phthalate CoA-transferase showed high substrate specificity for o-phthalate and did not accept isophthalate, terephthalate or 3-fluoro-o-phthalate whereas the putative o-phthalyl-CoA decarboxylase converted fluoro-o-phthalyl-CoA to fluoro-benzoyl-CoA. No decarboxylase activity was observed with isophthalyl-CoA or terephthalyl-CoA. Both enzyme activities were oxygen-insensitive and inducible only after growth with o-phthalate. Further degradation of benzoyl-CoA proceeds analogous to the well-established anaerobic benzoyl-CoA degradation pathway of nitrate-reducing bacteria. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Open-label, randomized, multicenter, phase III study to evaluate the safety and efficacy of benzoyl peroxide gel in long-term use in patients with acne vulgaris: A secondary publication.

PubMed

Kawashima, Makoto; Nagare, Toshitaka; Katsuramaki, Tsuneo

2017-06-01

An open-label, randomized, multicenter study was conducted to evaluate the safety and efficacy of long-term use of 2.5% and 5% benzoyl peroxide (BPO) gels administrated once daily for 52 weeks to Japanese patients with acne vulgaris. The efficacy of the study drugs was evaluated by counting inflammatory lesions and non-inflammatory lesions. Safety was evaluated based on adverse events, local skin tolerability scores and laboratory test values. In total, 458 subjects were included in the efficacy and safety analyses. The total lesion count, the efficacy end-point, was similarly changed both in the 2.5% and 5% BPO groups over the course of the study. The median rates of reduction from baseline to week 12 were approximately 65%. Thereafter, the counts were maintained at a reduced level without increasing until week 52. The median rates at week 52 were approximately 80%. Similar trends were observed for inflammatory and non-inflammatory lesion counts. Bacteriological evaluation indicated similar distribution of the minimum inhibitory concentration of each of the antibacterial drugs against Propionibacterium acnes between the values at baseline and at week 52, suggesting that long-term use did not result in changes in the drug sensitivity. The incidence of adverse events was 84.0% in the 2.5% BPO group and 87.2% in the 5% BPO group. Many of the adverse events occurred within the first month and were mild or moderate in severity and transient. The results suggest that both 2.5% and 5% BPO gels are effective and safe for long-term treatment of patients with acne vulgaris. © 2017 The Authors. The Journal of Dermatology published by John Wiley & Sons Australia, Ltd on behalf of Japanese Dermatological Association.

Two biflavonoids from Ouratea flava stem bark.

PubMed

Mbing, Joséphine Ngo; Pegnyemb, Dieudonné Emmanuel; Tih, Raphael Ghogomu; Sondengam, Beibam Lucas; Blond, Alain; Bodo, Bernard

2003-06-01

In a chemical investigation on the stem bark of Ouratea flava, two biflavonoids: 1-[3-(2,4-dihydroxy-benzoyl)-4,5,6-trihydroxy-2-(4-hydroxy-phenyl)-benzofuran-7-yl] -3-(4-hydroxy-phenyl) -propenone (flavumone A) and 3-(2,4-dihydroxy-benzoyl)-4-hydroxy-2,7-bis-(4-hydroxy-phenyl) -7,8- dihydro-furo[2,3-f]chromen-9-on (flavumone B) were isolated along with five known flavonoids. Their structures were established by various analyses including 2D-NMR spectroscopy.

Studies on thermo-mechanical properties of chemically treated jute-polyester composite

NASA Astrophysics Data System (ADS)

Chaudhari, Vikas; Chandekar, Harichandra; Saboo, Jayesh; Mascarenhas, Adlete

2018-03-01

The effect of chemical treatments on jute-polyester composites is studied in this paper. The jute fabrics are chemically treated with NaOH and benzoyl chloride and its tensile and visco-elastic properties are compared with untreated jute composite. The NaOH treated jute-polyester composite show superior tensile strength and modulus compared to other jute-polyester composites. The glass transition temperature obtained from DMA shift to higher temperature for composites in comparison to polyester resin, this is due to restriction of mobility in chains due to introduction of jute reinforcement. The DMA results also show favourable results towards NaOH treatment i.e. higher storage modulus and lower tan δ values relative to untreated jute-polyester composite. The benzoyl treated jute-polyester composite however do not show promising results which may be attributed to the fact that the adhesion properties associated with similar ester functional groups in the benzoyl treated jute fabric and polyester resin were not obtained.

Synthesis, structure, and reactivity of N-benzoyl iminophosphoranes ortho lithiated at the benzoyl group.

PubMed

Aguilar, David; Fernández, Ignacio; Cuesta, Luciano; Yañez-Rodríguez, Víctor; Soler, Tatiana; Navarro, Rafael; Urriolabeitia, Esteban P; López Ortiz, Fernando

2010-10-01

Ortho lithiation of N-benzamido-P,P,P-triaryliminophosphoranes through deprotonation with alkyllithium bases was achieved with ortho-C═O and ortho-P═N chemoselectivity. However, the synthetic scope of these processes was rather limited. Ortho-lithiated N-benzamido-P,P,P-triphenyliminophosphorane 8 was efficiently prepared via lithium/halogen exchange of the corresponding ortho-brominated precursor with s-BuLi in THF at -90 °C. The reaction of 8 with a variety of electrophiles provides an easy and mild method for the regioselective synthesis of ortho-modified iminophosphoranes via C-C (alkylation and hydroxyalkylation) and C-X (X = I, Si, P, Sn, and Hg) bond-forming reactions. NMR characterization of 8 in THF solution showed that 8 exists as an equilibrium mixture of one monomer and two dimers. The Li atoms of these species become members of five-membered rings through chelation by the ortho-metalated carbon and the carbonyl oxygen. The dimers differ in the relative orientation of the two chelates with respect to the plane defined by the C(2)Li(2) core. The equilibrium between all species is established by splitting the dimers into monomers and subsequent recombination with formation of a different dimer.

Erythromycin and Benzoyl Peroxide Topical

MedlinePlus

... on to step 5. If your medication comes in small pouches, use scissors or your fingers to tear off the top at the notched tab. Do not open the pouch with your teeth. Squeeze the contents of the pouch onto your ...

Erythema-directed digital photography for the enhanced evaluation of topical treatments for acne vulgaris.

PubMed

Micali, G; Dall'Oglio, F; Tedeschi, A; Lacarrubba, F

2018-01-31

Erythema-directed digital photography is a novel method for evaluating the efficacy and tolerability of topical acne treatments. Here, we describe three case reports in which erythema-directed digital photography was used to evaluate acne before and after up to 12 weeks of treatment with clindamycin 1%/tretinoin 0.025% (Clin-RA). Erythema-directed digital photography was used to evaluate acne in three patients with mild-to-moderate facial acne, two of whom had refused to continue previous topical acne treatment (benzoyl peroxide 5% and clindamycin 1%/benzoyl peroxide 5%) due to persistent irritation. Acne lesions and erythema were evaluated using standard clinical photography and erythema-directed digital photography (VISIA-CR ™ system) before and after 8-12 weeks of treatment with Clin-RA. Erythema-directed digital photography revealed background erythema from previous topical acne treatments that was not evident from standard clinical photographs and allowed a better visualization of both inflammatory and non-inflammatory lesions. In all patients, there was a clear improvement in background erythema and a reduction in acne lesions following treatment with Clin-RA. This study has demonstrated for the first time that erythema-directed digital photography can enhance the evaluation of the efficacy and tolerability of topical acne treatments. These cases show that Clin-RA was associated with improved efficacy and tolerability vs previous treatments with topical monotherapy (benzoyl peroxide 5%) or a topical fixed-dose combination (clindamycin 1%/benzoyl peroxide 5%). © 2018 The Authors. Skin Research and Technology Published by John Wiley & Sons Ltd.

Development and Binding Mode Assessment of N-[4-[2-propyn-1-yl[(6S)-4,6,7,8-tetrahydro-2-(hydroxymethyl)-4-oxo-3H-cyclopenta[g]quinazolin-6-yl]amino]benzoyl]-L-γ-glutamyl-D-glutamic acid (BGC 945), a Novel Thymidylate Synthase Inhibitor that Targets Tumor Cells

PubMed Central

Tochowicz, Anna; Dalziel, Sean; Eidam, Oliv; O’Connell, Joseph D.; Griner, Sarah; Finer-Moore, Janet S.; Stroud, Robert M.

2013-01-01

N-[4-[2-propyn-1-yl[(6S)-4,6,7,8-tetrahydro-2-(hydroxymethyl)-4-oxo-3H-cyclopenta[g]quinazolin-6-yl]amino]benzoyl]-L-γ-glutamyl-D-glutamic acid 1 (BGC 945, now known as ONX 0801), is a small molecule thymidylate synthase (TS) inhibitor discovered at the Institute of Cancer Research in London. It is licensed by Onyx Pharmaceuticals and is in Phase 1 clinical studies. It is a novel antifolate drug resembling TS inhibitors plevitrexed and raltitrexed that combines enzymatic inhibition of thymidylate synthase with α-folate receptor-mediated targeting of tumor cells. Thus, it has potential for efficacy with lower toxicity due to selective intracellular accumulation through α-folate receptor (α-FR) transport. The α-FR, a cell-surface receptor glycoprotein, which is over expressed mainly in ovarian and lung cancer tumors, has an affinity for 1 similar to that for its natural ligand, folic acid. This study describes a novel synthesis of 1, an X-ray crystal structure of its complex with Escherichia coli TS and 2’-deoxyuridine-5’-monophosphate, and a model for a similar complex with human TS. PMID:23710599

Antitubercular cassane furanoditerpenoids from the roots of Caesalpinia pulcherrima.

PubMed

Promsawan, Netnapa; Kittakoop, Prasat; Boonphong, Surat; Nongkunsarn, Pakawan

2003-08-01

Activity-guided fractionation of a root extract of Caesalpinia pulcherrima led to the isolation of two cassane-furanoditerpenoids, 6 beta-benzoyl-7 beta-hydroxyvouacapen-5 alpha-ol (1) and 6 beta-cinnamoyl-7beta-hydroxyvouacapen-5 alpha-ol (2). Compound 2 showed strong antitubercular activity with a minimum inhibitory concentration (MIC) of 6.25 microg/mL, whereas the benzoyl analogue (1) was less active (MIC 25 microg/mL). Both compounds expressed moderate cytotoxic activity towards KB (human oral carcinonoid cancer), BC (human breast cancer) and NCl-H187 (small cell lung cancer) cell lines.

Polyamideimides containing carbonyl and ether connecting groups

NASA Technical Reports Server (NTRS)

Havens, S. J.; Hergenrother, P. M.

1990-01-01

Polyamidenimides were prepared from the reaction of trimellitic anhydride chloride with seven diamines containing carbonyl and ether groups between the aromatic rings. Several of these polyamideimides were semicrystalline as evidenced by wide-angle X-ray diffraction and differential scanning calorimetry. Glass transition temperatures ranged between 187 and 245 C, and crystalline transition temperatures ranged between 317 and 416 C. A series of copolyamideimides from a mixture of 1,3-bis(4-aminophenoxy 4-prime-benzoyl) benzene and 1,4-bis(4-aminophenoxy 4-prime-benzoyl)benzene were similarly prepared. These copolyamideimides were semicrystalline and formed tough, solvent resistant films with good tensile properties.

Benzil bis-(ketazine).

PubMed

Patra, Goutam Kumar; Mukherjee, Anindita; Ng, Seik Weng

2009-07-04

1,1',2,2'-tetra-phenyl-2,2'-azinodiethanone), C(28)H(20)N(2)O(2), was obtained by the reaction of benzil monohydrazone with chromium(III) nitrate. The dibenzyl-idene hydrazine unit is nearly planar (r.m.s. deviation = 0.073 Å) and the two benzoyl units are oriented almost perpendicular to it [dihedral angle = 87.81 (2), 87.81 (2)°]. The mol-ecules are linked into chains along the c axis by C-H⋯O hydrogen bonds and the chains are cross-linked via C-H⋯π inter-actions involving the benzoyl phenyl rings.

Separation and determination of impurities in paracetamol, codeine and pitophenone in the presence of fenpiverinium in combined suppository dosage form.

PubMed

Vojta, Jiří; Hanzlík, Pavel; Jedlička, Aleš; Coufal, Pavel

2015-01-01

A new HPLC method for separation and determination of impurities in paracetamol, codeine phosphate hemihydrate and pitophenone hydrochloride in the presence of fenpiverinium bromide in combined suppository dosage form was developed and validated. The separation of paracetamol and its impurities 4-aminophenol, 4-nitrophenol, 4-chloracetanilid; codeine and its impurities methylcodeine, morphine, codeine dimer and 10-hydroxycodeine; pitophenone and its impurities 2-[4-[2-(1-piperidinyl)ethoxy]benzoyl] benzoic acid, 2-[4-[2-(1-piperidinyl)ethoxy]benzoyl]benzoic acid 2-(1-piperidinyl)-ethyl ester, methyl ester of 2-(4-hydroxybenzoyl) benzoic acid and fenpiverinium was achieved by using ion-pair reversed phase liquid chromatography with UV detection. Validation parameters such as the precision, accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ) and robustness were verified for all the mentioned impurities of codeine phosphate hemihydrate and 4-aminophenol and 2-[4-[2-(1-piperidinyl)ethoxy]benzoyl] benzoic acid as the main degradation products of paracetamol and pitophenone hydrochloride, respectively. The described method was found to be useful for analysis of the stability samples and therefore suitable for routine purity testing of the drug product. Copyright © 2014 Elsevier B.V. All rights reserved.

Docking Simulation of the Binding Interactions of Saxitoxin Analogs Produced by the Marine Dinoflagellate Gymnodinium catenatum to the Voltage-Gated Sodium Channel Nav1.4.

PubMed

Durán-Riveroll, Lorena M; Cembella, Allan D; Band-Schmidt, Christine J; Bustillos-Guzmán, José J; Correa-Basurto, José

2016-05-06

Saxitoxin (STX) and its analogs are paralytic alkaloid neurotoxins that block the voltage-gated sodium channel pore (Nav), impeding passage of Na⁺ ions into the intracellular space, and thereby preventing the action potential in the peripheral nervous system and skeletal muscle. The marine dinoflagellate Gymnodinium catenatum produces an array of such toxins, including the recently discovered benzoyl analogs, for which the mammalian toxicities are essentially unknown. We subjected STX and its analogs to a theoretical docking simulation based upon two alternative tri-dimensional models of the Nav1.4 to find a relationship between the binding properties and the known mammalian toxicity of selected STX analogs. We inferred hypothetical toxicities for the benzoyl analogs from the modeled values. We demonstrate that these toxins exhibit different binding modes with similar free binding energies and that these alternative binding modes are equally probable. We propose that the principal binding that governs ligand recognition is mediated by electrostatic interactions. Our simulation constitutes the first in silico modeling study on benzoyl-type paralytic toxins and provides an approach towards a better understanding of the mode of action of STX and its analogs.

Docking Simulation of the Binding Interactions of Saxitoxin Analogs Produced by the Marine Dinoflagellate Gymnodinium catenatum to the Voltage-Gated Sodium Channel Nav1.4

PubMed Central

Durán-Riveroll, Lorena M.; Cembella, Allan D.; Band-Schmidt, Christine J.; Bustillos-Guzmán, José J.; Correa-Basurto, José

2016-01-01

Saxitoxin (STX) and its analogs are paralytic alkaloid neurotoxins that block the voltage-gated sodium channel pore (Nav), impeding passage of Na+ ions into the intracellular space, and thereby preventing the action potential in the peripheral nervous system and skeletal muscle. The marine dinoflagellate Gymnodinium catenatum produces an array of such toxins, including the recently discovered benzoyl analogs, for which the mammalian toxicities are essentially unknown. We subjected STX and its analogs to a theoretical docking simulation based upon two alternative tri-dimensional models of the Nav1.4 to find a relationship between the binding properties and the known mammalian toxicity of selected STX analogs. We inferred hypothetical toxicities for the benzoyl analogs from the modeled values. We demonstrate that these toxins exhibit different binding modes with similar free binding energies and that these alternative binding modes are equally probable. We propose that the principal binding that governs ligand recognition is mediated by electrostatic interactions. Our simulation constitutes the first in silico modeling study on benzoyl-type paralytic toxins and provides an approach towards a better understanding of the mode of action of STX and its analogs. PMID:27164145

21 CFR 184.1157 - Benzoyl peroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

....181), Romano cheese (§ 133.183), and Swiss and emmentaler cheese (§ 133.195) in part 133 of this...; milk used for production of Asiago fresh and Asiago soft cheese (§ 133.102), Asiago medium cheese (§ 133.103), Asiago old cheese (§ 133.104), Blue cheese (§ 133.106), Caciocavallo siciliano chesse (§ 133...

21 CFR 184.1157 - Benzoyl peroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

....181), Romano cheese (§ 133.183), and Swiss and emmentaler cheese (§ 133.195) in part 133 of this...; milk used for production of Asiago fresh and Asiago soft cheese (§ 133.102), Asiago medium cheese (§ 133.103), Asiago old cheese (§ 133.104), Blue cheese (§ 133.106), Caciocavallo siciliano chesse (§ 133...

21 CFR 184.1157 - Benzoyl peroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

....181), Romano cheese (§ 133.183), and Swiss and emmentaler cheese (§ 133.195) in part 133 of this...; milk used for production of Asiago fresh and Asiago soft cheese (§ 133.102), Asiago medium cheese (§ 133.103), Asiago old cheese (§ 133.104), Blue cheese (§ 133.106), Caciocavallo siciliano chesse (§ 133...

21 CFR 184.1157 - Benzoyl peroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

....181), Romano cheese (§ 133.183), and Swiss and emmentaler cheese (§ 133.195) in part 133 of this...; milk used for production of Asiago fresh and Asiago soft cheese (§ 133.102), Asiago medium cheese (§ 133.103), Asiago old cheese (§ 133.104), Blue cheese (§ 133.106), Caciocavallo siciliano chesse (§ 133...

21 CFR 184.1157 - Benzoyl peroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

....181), Romano cheese (§ 133.183), and Swiss and emmentaler cheese (§ 133.195) in part 133 of this...; milk used for production of Asiago fresh and Asiago soft cheese (§ 133.102), Asiago medium cheese (§ 133.103), Asiago old cheese (§ 133.104), Blue cheese (§ 133.106), Caciocavallo siciliano chesse (§ 133...

1,2-diketones promoted degradation of poly(epsilon-caprolactone)

NASA Astrophysics Data System (ADS)

Danko, Martin; Borska, Katarina; Ragab, Sherif Shaban; Janigova, Ivica; Mosnacek, Jaroslav

2012-07-01

Photochemical reactions of Benzil and Camphorquinone were used for modification of poly(ɛ-caprolactone) polymer films. Photochemistry of dopants was followed by infrared spectroscopy, changes on polymer chains of matrix were followed by gel permeation chromatography. Benzoyl peroxide was efficiently photochemically generated from benzyl in solid polymer matrix in the presence of air. Following decomposition of benzoyl peroxide led to degradation of matrix. Photochemical transformation of benzil in vacuum led to hydrogen abstraction from the polymer chains in higher extent, which resulted to chains recombination and formation of gel. Photochemical transformation of camphorquinone to corresponding camphoric peroxide was not observed. Only decrease of molecular weight of polymer matrix doped with camphorquinone was observed during the irradiation.

Benzil bis­(ketazine)

PubMed Central

Patra, Goutam Kumar; Mukherjee, Anindita; Ng, Seik Weng

2009-01-01

The title compound (systematic name: 1,1′,2,2′-tetra­phenyl-2,2′-azinodiethanone), C28H20N2O2, was obtained by the reaction of benzil monohydrazone with chromium(III) nitrate. The dibenzyl­idene hydrazine unit is nearly planar (r.m.s. deviation = 0.073 Å) and the two benzoyl units are oriented almost perpendicular to it [dihedral angle = 87.81 (2), 87.81 (2)°]. The mol­ecules are linked into chains along the c axis by C—H⋯O hydrogen bonds and the chains are cross-linked via C—H⋯π inter­actions involving the benzoyl phenyl rings. PMID:21583456

A sacrificial millipede altruistically protects its swarm using a drone blood enzyme, mandelonitrile oxidase

PubMed Central

Ishida, Yuko; Kuwahara, Yasumasa; Dadashipour, Mohammad; Ina, Atsutoshi; Yamaguchi, Takuya; Morita, Masashi; Ichiki, Yayoi; Asano, Yasuhisa

2016-01-01

Soldiers of some eusocial insects exhibit an altruistic self-destructive defense behavior in emergency situations when attacked by large enemies. The swarm-forming invasive millipede, Chamberlinius hualienensis, which is not classified as eusocial animal, exudes irritant chemicals such as benzoyl cyanide as a defensive secretion. Although it has been thought that this defensive chemical was converted from mandelonitrile, identification of the biocatalyst has remained unidentified for 40 years. Here, we identify the novel blood enzyme, mandelonitrile oxidase (ChuaMOX), which stoichiometrically catalyzes oxygen consumption and synthesis of benzoyl cyanide and hydrogen peroxide from mandelonitrile. Interestingly the enzymatic activity is suppressed at a blood pH of 7, and the enzyme is segregated by membranes of defensive sacs from mandelonitrile which has a pH of 4.6, the optimum pH for ChuaMOX activity. In addition, strong body muscle contractions are necessary for de novo synthesis of benzoyl cyanide. We propose that, to protect its swarm, the sacrificial millipede also applies a self-destructive defense strategy—the endogenous rupturing of the defensive sacs to mix ChuaMOX and mandelonitrile at an optimum pH. Further study of defensive systems in primitive arthropods will pave the way to elucidate the evolution of altruistic defenses in the animal kingdom. PMID:27265180

A sacrificial millipede altruistically protects its swarm using a drone blood enzyme, mandelonitrile oxidase.

PubMed

Ishida, Yuko; Kuwahara, Yasumasa; Dadashipour, Mohammad; Ina, Atsutoshi; Yamaguchi, Takuya; Morita, Masashi; Ichiki, Yayoi; Asano, Yasuhisa

2016-06-06

Soldiers of some eusocial insects exhibit an altruistic self-destructive defense behavior in emergency situations when attacked by large enemies. The swarm-forming invasive millipede, Chamberlinius hualienensis, which is not classified as eusocial animal, exudes irritant chemicals such as benzoyl cyanide as a defensive secretion. Although it has been thought that this defensive chemical was converted from mandelonitrile, identification of the biocatalyst has remained unidentified for 40 years. Here, we identify the novel blood enzyme, mandelonitrile oxidase (ChuaMOX), which stoichiometrically catalyzes oxygen consumption and synthesis of benzoyl cyanide and hydrogen peroxide from mandelonitrile. Interestingly the enzymatic activity is suppressed at a blood pH of 7, and the enzyme is segregated by membranes of defensive sacs from mandelonitrile which has a pH of 4.6, the optimum pH for ChuaMOX activity. In addition, strong body muscle contractions are necessary for de novo synthesis of benzoyl cyanide. We propose that, to protect its swarm, the sacrificial millipede also applies a self-destructive defense strategy-the endogenous rupturing of the defensive sacs to mix ChuaMOX and mandelonitrile at an optimum pH. Further study of defensive systems in primitive arthropods will pave the way to elucidate the evolution of altruistic defenses in the animal kingdom.

21 CFR 177.2450 - Polyamide-imide resins.

Code of Federal Regulations, 2014 CFR

2014-04-01

... polyamide-imide resins are derived from the condensation reaction of substantially equimolar parts of.... 31957-38-7) derived from the condensation reaction of equimolar parts of benzoyl chloride-3,4...

Synthesis, structural, optical and thermal properties of N-methyl-N-aryl benzamide organic single crystals grown by a slow evaporation technique

NASA Astrophysics Data System (ADS)

Prabukanthan, P.; Lakshmi, R.; Harichandran, G.; Kumar, C. Sudarsana

2018-03-01

The organic materials, N-methyl-N-aryl benzamides were synthesized from benzoylation of N-methyl-4-nitrobenzenamine (MNBA) using suitably substituted benzoyl chlorides. The products were purified by recrystallization and their single crystal were grown by a slow evaporation technique. The crystals were characterized by FTIR, UV-Vis-NIR, 1H &13C NMR, and single & powder X-ray diffraction. Thermal stability of the crystals was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Dielectric and NLO properties of MNPB, FMNPB and MMNPB crystals were studied. The second harmonic generation (SHG) has been confirmed by the Kurtz powder test for all these crystals and the SHG efficiency of MMNPB crystal was found to be 2.25 times higher than that of KDP crystal.

K-ras mutations in benzotrichloride-induced lung tumors of A/J mice.

PubMed

You, M; Wang, Y; Nash, B; Stoner, G D

1993-06-01

Benzotrichloride (BTC) is used extensively as a chemical intermediate in the synthesis of benzoyl chloride and benzoyl peroxide. Epidemiological data suggest that BTC is a human lung carcinogen. BTC is also a carcinogen in the A/J mouse lung tumor bioassay. Activated K-ras protooncogenes were detected in BTC-induced lung tumors from A/J mice. The polymerase chain reaction was used to amplify specific DNA segments likely to contain activating mutations, and the amplified DNAs were sequenced to identify the mutation. The activating mutation present in the K-ras gene from all BTC-induced lung tumors (24/24) was a GC-->AT transition in codon 12. Thus, BTC may exert its carcinogenic action by activation of the K-ras protooncogene through a genotoxic mechanism.

1,2-diketones promoted degradation of poly(epsilon-caprolactone)

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

Danko, Martin; Borska, Katarina; Ragab, Sherif Shaban

2012-07-11

Photochemical reactions of Benzil and Camphorquinone were used for modification of poly({epsilon}-caprolactone) polymer films. Photochemistry of dopants was followed by infrared spectroscopy, changes on polymer chains of matrix were followed by gel permeation chromatography. Benzoyl peroxide was efficiently photochemically generated from benzyl in solid polymer matrix in the presence of air. Following decomposition of benzoyl peroxide led to degradation of matrix. Photochemical transformation of benzil in vacuum led to hydrogen abstraction from the polymer chains in higher extent, which resulted to chains recombination and formation of gel. Photochemical transformation of camphorquinone to corresponding camphoric peroxide was not observed. Only decreasemore » of molecular weight of polymer matrix doped with camphorquinone was observed during the irradiation.« less

Computational study of the synthesis of benzoin derivatives from benzil

NASA Astrophysics Data System (ADS)

Topal, Kevser Göçmen; Unaleroglu, Canan; Aviyente, Viktorya

Benzil (1,2-diphenylethane-1,2-dione) undergoes cyanide catalyzed condensation with benzaldehyde to yield O-benzoylated benzoin (2-benzoyl-1,2-diphenylethanone). In this study, the experimentally suggested mechanism has been modeled with PM3 and verified with B3LYP. The effect of the substituent on the reaction yield has been rationalized by considering two benzil derivatives; 1,2-bis(2-chlorophenyl)ethane-1,2-dione and 1,2-bis(2-fluorophenyl)ethane-1,2-dione and three benzaldehyde derivatives; o-fluorobenzaldehyde, o-methylbenzaldehyde and 2-pyridinecarboxaldehyde. The effect of the solvent has been modeled by using the isodensity-surface polarizable continuum (IPCM) model. Reactivity descriptors have been used to justify the reactivity differences of the various substituents.

21 CFR 172.814 - Hydroxylated lecithin.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) With hydrogen peroxide, benzoyl peroxide, lactic acid, and sodium hydroxide. (2) With hydrogen peroxide, acetic acid, and sodium hydroxide. (b) It is used or intended for use, in accordance with good...

21 CFR 172.814 - Hydroxylated lecithin.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) With hydrogen peroxide, benzoyl peroxide, lactic acid, and sodium hydroxide. (2) With hydrogen peroxide, acetic acid, and sodium hydroxide. (b) It is used or intended for use, in accordance with good...

Reconstructing metabolic pathways of a member of the genus Pelotomaculum suggesting its potential to oxidize benzene to carbon dioxide with direct reduction of sulfate.

PubMed

Dong, Xiyang; Dröge, Johannes; von Toerne, Christine; Marozava, Sviatlana; McHardy, Alice C; Meckenstock, Rainer U

2017-03-01

The enrichment culture BPL is able to degrade benzene with sulfate as electron acceptor and is dominated by an organism of the genus Pelotomaculum. Members of Pelotomaculum are usually known to be fermenters, undergoing syntrophy with anaerobic respiring microorganisms or methanogens. By using a metagenomic approach, we reconstructed a high-quality genome (∼2.97 Mbp, 99% completeness) for Pelotomaculum candidate BPL. The proteogenomic data suggested that (1) anaerobic benzene degradation was activated by a yet unknown mechanism for conversion of benzene to benzoyl-CoA; (2) the central benzoyl-CoA degradation pathway involved reductive dearomatization by a class II benzoyl-CoA reductase followed by hydrolytic ring cleavage and modified β-oxidation; (3) the oxidative acetyl-CoA pathway was utilized for complete oxidation to CO2. Interestingly, the genome of Pelotomaculum candidate BPL has all the genes for a complete sulfate reduction pathway including a similar electron transfer mechanism for dissimilatory sulfate reduction as in other Gram-positive sulfate-reducing bacteria. The proteome analysis revealed that the essential enzymes for sulfate reduction were all formed during growth with benzene. Thus, our data indicated that, besides its potential to anaerobically degrade benzene, Pelotomaculum candidate BPL is the first member of the genus that can perform sulfate reduction. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A phase IV, open-label study evaluating the use of triple-combination therapy with minocycline HCl extended-release tablets, a topical antibiotic/retinoid preparation and benzoyl peroxide in patients with moderate to severe acne vulgaris.

PubMed

Zaenglein, Andrea L; Shamban, Ava; Webster, Guy; Del Rosso, James; Dover, Jeffrey S; Swinyer, Leonard; Stein, Linda; Lin, Xiaoming; Draelos, Zoe; Gold, Michael; Thiboutot, Diane

2013-06-01

Moderate to severe acne vulgaris is often treated with a combination of an oral antibiotic, topical antibiotic/retinoid, and benzoyl peroxide (BP), but data are limited on the efficacy of this and other combination regimens that incorporate both oral and topical therapies.
Patients were required to be aged 12-30 years with moderate to severe acne (grades 3-4 acne on the Investigator's Global Assessment [IGA]) and deemed potential candidates for treatment with isotretinoin. Enrolled patients were given triple-combination therapy, defined in this study as oral minocycline HCl extended release 1 mg/kg QD, 6% BP foaming cloths used QD, and clindamycin phosphate 1.2%/tretinoin 0.025% gel applied QD, and were evaluated at baseline and weeks 2, 4, 8, and 12.
A total of 97 patients were enrolled in the study. At week 12, 89% of patients had at least a one-grade improvement from baseline IGA and 96% had at least a one-grade improvement from baseline Global Aesthetic Improvement Scale score. Mean ± SD in- flammatory, non-inflammatory, and total lesion counts decreased from baseline by 61.8% ± 38.3%, 48.8% ± 34.5%, and 56.5% ± 29.9%, respectively. The percentage of patients evaluated as candidates for isotretinoin by independent photographic review was 77% (69/90) at baseline and only 16% (14/90) at week 12. Treatment-related adverse events (AEs) occurred in eight of 97 (8%) patients. Triplecombination therapy was not associated with any serious AEs or AEs leading to discontinuation.
Triple-combination therapy was well tolerated and substantially reduced facial acne lesion counts, with 84% of patients judged to no longer be candidates for isotretinoin therapy by study end. These data support the clinical observation that a triple-combination regimen incorporating oral minocycline (dosed by patient weight), BP foaming cloths 6% QD, and clindamycin phosphate 1.2%/ tretinoin 0.025% gel QD can substantially improve moderate to severe acne vulgaris.

Hydrolysis and nucleophilic substitution of model and ultimate carcinogens

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

Helmick, J.S.

1992-01-01

The hydrolysis reaction of the Model Carcinogen O-pivaloyl-N-(4-chlorophenyl)hydroxylamine in aqueous buffer (pH 7.0-10.0) proceeds by was of a nitrenium ion intermediate. The products formed from this process are predominately 2,4-dichloroaniline, and 2-hydroxy-4-chloro-pivalanilide. At pH 10-13 the rate becomes dependent upon hydroxide. The product that is formed is 4-chlorophenylhydroxylamine. 4-Chlorophenyl-hydroxylamine is formed by basic ester hydrolysis determined by an [sup 18]O GC-MS experiment. The reaction of O-pivaloyl-N-(4-chlorophenyl)hydroxylamine in an aqueous diethylamine (pH 11.3) buffer gave 4-chlorophenyl-N,N-diethylhydrazine as the substitution product in a 16% yield. The reaction of O-pivaloyl-N-(4-methylphenyl)hydroxylamine with diethylamine gave a 1% yield of the hydrazine product. The reaction ofmore » N,N-dimethylanline and aniline with ring-substituted O-pivaloyl-N-arylhydroxylamines in MeOH generates products of nucleophilic attack on the nitrogen of the hydroxylamine derivative. The hydrolysis of the ultimate carcinogen N-(sulfonatooxy)-N-4-aminobiphenyl proceeds by two consecutive pseudo-first-order processes and generates predominately a product of nucleophilic attack by chloride ion at the ortho position of the aromatic ring. A labile intermediate identified as N-acetypl-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine has been detected by NMR. This intermediate rearranges to form 4-hydroxy-3-phenylacetanilide. The hydrolysis of N-benzoyl-4-hydroxy-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine proceeds by way of two consecutive pseudo-first-order processes. The hydrolysis of N-benzoyl-4-methoxy-4-phenyl-2,5-cyclohexadienone imine also proceeds by two consecutive pseudo-first-order processes. Spectroscopic evidence of two diastereomeric intermediates formed from the hydrolysis of the N-benzoyl imines were tentatively identified as N-benzoyl-N-hydroxy-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine.« less

Pilot study of contact sensitization to rubber allergens and bisphenol A amongst dental students.

PubMed

Lyapina, Maya Grigorievna; Krasteva, Assya; Dencheva, Maria; Tzekova, Mariana; Nikolov, Georgy; Yaneva-Deliverska, Mariela; Kisselova-Yaneva, Angelina

2017-05-08

The aim of this study has been to evaluate the rate of contact sensitization to some rubber allergens and to bisphenol A (BPA) amongst students of dental medicine and dental patients. A total of 50 participants were included in the study: 40 students of dental medicine exposed to the studied rubber allergens and BPA-based dental materials during the course of their education; 10 dental patients without occupational exposure to the latter substances served as a control group. All of them were patch-tested with the studied rubber allergens and bisphenol A. Highest was the sensitizing action of carba mix, followed by benzoyl peroxide and mercapto mix. The sensitization rate for carba mix was significantly higher for dental students as well as for the whole studied population, if compared to the one for thiuram mix (Chi² = 12.9, p < 0.001; Chi² = 13.9, p < 0.001), bisphenol A (Chi² = 8.9, p < 0.001; Chi² = 11.9, p < 0.001), toluenesulfonamide formaldehyde resin (Chi² = 10.7, p < 0.001; Chi² = 13.9, p < 0.001) and benzoyl peroxide (Chi² = 4.7, p = 0.03; Chi² = 5.8, p = 0.016), and for dental patients, if compared to the one for mercapto mix (Chi² = 7.07, p = 0.008). Concomitant positive skin patch-test reactions to carba mix and to benzoyl peroxide, and to all the studied allergens were established. Carba mix could be outlined as a sensitizer of paramount importance for dental students as well as for dental patients. Benzoyl peroxide was the second ranked sensitizer for dental students. Positive skin patch-test reactions to bisphenol A and toluenesulfonamide formaldehyde resin were established only among the group of dental students. Int J Occup Med Environ Health 2017;30(3):397-405. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

21 CFR 172.814 - Hydroxylated lecithin.

Code of Federal Regulations, 2014 CFR

2014-04-01

... resultant product has an acetyl value of 30 to 38: (1) With hydrogen peroxide, benzoyl peroxide, lactic acid, and sodium hydroxide. (2) With hydrogen peroxide, acetic acid, and sodium hydroxide. (b) It is used or...

Chem Ed Compacts.

ERIC Educational Resources Information Center

Wolf, Walter A., Ed.

1979-01-01

Tips are presented for chemistry teachers on the use of acid-base half-reactions in review lessons, the use of calculators by chemistry students, significant figures, and the preparation of benzoyl peroxide from acne medicine. (BB)

A multicentre, randomized, single-blind, parallel-group study comparing the efficacy and tolerability of benzoyl peroxide 3%/clindamycin 1% with azelaic acid 20% in the topical treatment of mild-to-moderate acne vulgaris.

PubMed

Schaller, M; Sebastian, M; Ress, C; Seidel, D; Hennig, M

2016-06-01

Mild-to-moderate acne vulgaris is treated with a range of mono- and combination therapies; however, clinical evidence is still required to optimize treatment recommendations. To compare the efficacy, tolerability and safety of a combination of benzoyl peroxide 3% and clindamycin 1% (BPO + CLN) with azelaic acid 20% (AzA) for the topical treatment of mild-to-moderate acne vulgaris. This was a randomized, assessor-blinded, parallel-group, multicentre study conducted in Germany. Patients with a confirmed diagnosis of acne vulgaris, aged 12-45 years, were randomized 1 : 1 to once-daily BPO + CLN gel or twice-daily AzA cream for up to 12 weeks. The primary endpoint was the percentage change in inflammatory lesions from baseline at Week 4. Secondary endpoints included total and inflammatory lesion counts and tolerability assessments. For selected secondary endpoints, inductive statistical analysis was performed post hoc. Patient safety was assessed by adverse event (AE) monitoring. Efficacy was assessed in the modified intent-to-treat (mITT) population [patients using ≥1 dose of study medication (ITT), plus baseline and ≥1 post-baseline lesion count (n = 215)]. There was a statistically significant difference in the primary endpoint, with a median decrease of -52.6% for BPO + CLN (n = 107) vs.-38.8% for AzA (n = 108; P = 0.0004). There was also a greater difference in secondary lesion endpoints at Week 12, with a median decrease in inflammatory lesions of -78.8% and -65.3% and total lesions of -69.0% and -53.9% with BPO + CLN and AzA, respectively (both P < 0.0001). Tolerability was acceptable for both treatments. Overall, 55.6% (BPO + CLN) and 69.7% (AzA) of patients reported treatment-emergent AEs, and 15.7% and 35.8% of patients experienced application site reactions with BPO + CLN (24 events; 17 patients) and AzA (60 events; 39 patients) treatment, respectively (ITT population). BPO + CLN demonstrated greater efficacy than AzA in the treatment of mild

Purification and characterization of an extracellular trypsin-like protease of Fusarium oxysporum var. lini.

PubMed

Barata, Ricardo Andrade; Andrade, Milton Hercules Guerra; Rodrigues, Roberta Dias; Castro, Ieso Miranda

2002-01-01

An alkaline serineprotease, capable of hydrolyzing Nalpha-benzoyl- dl arginine p-nitroanilide, was secreted by Fusarium oxysporum var. lini grown in the presence of gelatin as the sole nitrogen and carbon source. The protease was purified 65-fold to electrophoretic homogenity from the culture supernatant in a three-step procedure comprising QSepharose chromatography, affinity chromatography, and FPLC on a MonoQ column. SDS-PAGE analysis of the purified protein indicated an estimated molecular mass of 41 kDa. The protease had optimum activity at a reaction temperature of 45 degrees C and showed a rapid decrease of activity at 48 degrees C. The optimum pH was around 8.0. Characterization of the protease showed that Ca2+ and Mg2+ cations increased the activity, which was not inhibited by EDTA or 1,10-phenanthroline. The enzyme activity on Nalpha-benzoyl-DL arginine p-nitroanilide was inhibited by 4-(2-aminoethyl)-benzenesulfonyl fluoride hydrochloride, p-aminobenzamidine dihydrochloride, aprotinin, 3-4 dichloroisocoumarin, and N-tosyl-L-lysine chloromethyl ketone. The enzyme is also inhibited by substrate concentrations higher than 2.5 x 10(-4)M. The protease had a Michaelis-Menten constant of 0.16 mM and a V(max) of 0.60 mumol released product.min(-1).mg(-1) enzyme when assayed in a non-inhibiting substrate concentration. The activity on Nalpha-benzoyl- dl arginine p-nitroanilide was competitively inhibited by p-aminobenzamidine dihydrochoride. A K(i) value of 0.04 mM was obtained.

Photocytotoxicity of mTHPC (Temoporfin) Loaded Polymeric Micelles Mediated by Lipase Catalyzed Degradation

PubMed Central

Hofman, Jan-Willem; Carstens, Myrra G.; van Zeeland, Femke; Helwig, Conny; Flesch, Frits M.; Hennink, Wim E.

2008-01-01

Purpose To study the in vitro photocytotoxicity and cellular uptake of biodegradable polymeric micelles loaded with the photosensitizer mTHPC, including the effect of lipase-catalyzed micelle degradation. Methods Micelles of mPEG750-b-oligo(ɛ-caprolactone)5 (mPEG750-b-OCL5) with a hydroxyl (OH), benzoyl (Bz) or naphthoyl (Np) end group were formed and loaded with mTHPC by the film hydration method. The cellular uptake of the loaded micelles, and their photocytotoxicity on human neck squamous carcinoma cells in the absence and presence of lipase were compared with free and liposomal mTHPC (Fospeg®). Results Micelles composed of mPEG750-b-OCL5 with benzoyl and naphtoyl end groups had the highest loading capacity up to 30% (w/w), likely due to π–π interactions between the aromatic end group and the photosensitizer. MTHPC-loaded benzoylated micelles (0.5 mg/mL polymer) did not display photocytotoxicity or any mTHPC-uptake by the cells, in contrast to free and liposomal mTHPC. After dilution of the micelles below the critical aggregation concentration (CAC), or after micelle degradation by lipase, photocytotoxicity and cellular uptake of mTHPC were restored. Conclusion The high loading capacity of the micelles, the high stability of mTHPC-loaded micelles above the CAC, and the lipase-induced release of the photosensitizer makes these micelles very promising carriers for photodynamic therapy in vivo. PMID:18597164

Moisturizers for Acne

PubMed Central

Chularojanamontri, Leena; Tuchinda, Papapit; Kulthanan, Kanokvalai

2014-01-01

Acne is a chronic inflammatory disease of the pilosebaceous unit that affects almost all teenagers. Different treatments offer different modes of action, but aim to target acne pathology. Topical therapies, such as benzoyl peroxide, retinoids, antibiotics with alcohol-based preparations, and salicylic acid, can cause skin irritation resulting in a lack of patient adherence. Some physicians recommend patients use moisturizers as adjunctive treatment of acne, especially when either topical benzoyl peroxide or a retinoid is prescribed. Furthermore, some evidence shows that moisturizers can contribute independently to improve signs and symptoms of acne. Moisturizers contain three main properties, which are occlusive, humectant, and emollient effects. Currently, many moisturizers claim to be suitable for acne treatment. This article aims to provide a review of the active ingredients and properties of those moisturizers. Fifty-two moisturizers for acne were included for analysis. Most of the products (92%) have anti-inflammatory properties apart from occlusive, humectant, and emollient effects. Anti-acne medications, including salicylic acid, benzoyl peroxide, and retinol, were found respectively in 35, 10, and 8 percent of the moisturizer products containing anti-inflammatory properties. More than half of the products contain dimethicone and/or glycerin for its moisturizer property. Aloe vera and witch hazel are botanical anti-inflammatories that were commonly found in this study. Scientific data regarding some ingredients are discussed to provide a guide for physicians in selecting moisturizers for acne patients. PMID:24847408

Reductive, Coenzyme A-Mediated Pathway for 3-Chlorobenzoate Degradation in the Phototrophic Bacterium Rhodopseudomonas palustris

PubMed Central

Egland, Paul G.; Gibson, Jane; Harwood, Caroline S.

2001-01-01

We isolated a strain of Rhodopseudomonas palustris (RCB100) by selective enrichment in light on 3-chlorobenzoate to investigate the steps that it uses to accomplish anaerobic dechlorination. Analyses of metabolite pools as well as enzyme assays suggest that R. palustris grows on 3-chlorobenzoate by (i) converting it to 3-chlorobenzoyl coenzyme A (3-chlorobenzoyl–CoA), (ii) reductively dehalogenating 3-chlorobenzoyl–CoA to benzoyl-CoA, and (iii) degrading benzoyl-CoA to acetyl-CoA and carbon dioxide. R. palustris uses 3-chlorobenzoate only as a carbon source and thus incorporates the acetyl-CoA that is produced into cell material. The reductive dechlorination route used by R. palustris for 3-chlorobenzoate degradation differs from those previously described in that a CoA thioester, rather than an unmodified aromatic acid, is the substrate for complete dehalogenation. PMID:11229940

Synthesis, characterization, antioxidant and brine shrimp cytotoxic activity of novel 3-benzothioyl-1-(3-hydroxy-3-phenyl -3-propyl)-1-methylthiourea.

PubMed

Shoaib, Mohammad; Ullah, Abid; Shah, Syed Wadood Ali; Tahir, Muhammad Nawaz

2017-07-01

In the present research work novel ephedrine based thiourea derivative, 3-benzothioyl-1-(3-hydroxy-3-phenyl -3-propyl)-1-methylthiourea 4is synthesized and then characterized elemental analyzed via various techniques i.e., Proton NMR, carbon13 NMR and fatherly confirmed via X-ray crystallography. Compound 4 was then screened for their possible antioxidant and cytotoxic potentials. Benzoyl chloride was treated with an equimolar potassium thiocyanate in acetone to achieve benzoyl isothiocyantes. It was then treated with an equimolar (1R, 2S)-(-)-Ephedrine to obtain the 3-benzothioyl-1-(3-hydroxy-3-phenyl-3-propyl)-1-methyl thiourea4. It was then screened for antioxidant and cytotoxic potentials. The compound 4 showed excellent antioxidant activity almost comparable to ascorbic acid (standard) and have significant cytotoxic activity with LC 50 value 05±0.58 ppm.

Fixed-Dose Combination Gel of Adapalene and Benzoyl Peroxide plus Doxycycline 100 mg versus Oral Isotretinoin for the Treatment of Severe Acne: Efficacy and Cost Analysis.

PubMed

Penna, Pete; Meckfessel, Matthew H; Preston, Norman

2014-01-01

Acne vulgaris is a chronic skin disease with a high prevalence. Left untreated or inadequately treated, acne vulgaris can lead to psychological and physical scarring, as well as to unnecessary medical expenses. Oral isotretinoin is an effective treatment for severe resistant nodular and conglobate acne vulgaris. A regimen consisting of a fixed-dose combination of adapalene and benzoyl peroxide gel, 0.1%/2.5% (A-BPO) with oral doxycycline 100 mg (A-BPO/D) has been demonstrated to be efficacious and well tolerated in patients with severe acne and may be an alternative to oral isotretinoin for some patients with severe acne. The objective of this analysis was to compare the relative efficacy and associated costs of A-BPO/D versus oral isotretinoin. In this analysis, comparisons of relative efficacy were made using previously published studies involving similar patient populations with severe acne that warrant the use of oral isotretinoin. The pricing for oral doxycycline and oral isotretinoin was estimated based on the maximum allowable cost from 9 states, and the pricing for A-BPO was calculated as the range between the average wholesale price and the wholesale acquisition cost. For this analysis, 2 treatment models were generated to compare costs: (1) a basic treatment model that examined the costs of an initial regimen of either A-BPO/D or oral isotretinoin without considering probable outcomes, and (2) a long-term model that factored in likely treatment outcomes and subsequent treatments into associated costs. The basic treatment model assumed that patients would be prescribed a single regimen of A-BPO/D for 12 weeks or oral isotretinoin for 20 weeks. The long-term model considered the probability of each treatment successfully managing patients' acne, as well as likely additional regimens of A-BPO monotherapy or an additional regimen of oral isotretinoin. As a result of different treatment durations, the costs for each treatment were normalized to weekly cost of

Activity of lycorine analogs against the fish bacterial pathogen Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

In a continuing effort to discover natural products and natural product-based compounds for the control of columnaris disease in channel catfish (Ictalurus punctatus), seventeen lycorine analogs were synthesized, including new benzoyl analogs 6 – 16, and evaluated for antibacterial activity against ...

The "Mushroom Cloud" Demonstration Revisited

ERIC Educational Resources Information Center

Panzarasa, Guido; Sparnacci, Katia

2013-01-01

A revisitation of the classical "mushroom cloud" demonstration is described. Instead of aniline and benzoyl peroxide, the proposed reaction involves household chemicals such as alpha-pinene (turpentine oil) and trichloroisocyanuric acid ("Trichlor") giving an impressive demonstration of oxidation and combustion reactions that…

Reinterpretation of curved Hammett plots in reaction of nucleophiles with aryl benzoates: change in rate-determining step or mechanism versus ground-state stabilization.

PubMed

Um, Ik-Hwan; Han, Hyun-Joo; Ahn, Jung-Ae; Kang, Swan; Buncel, Erwin

2002-11-29

A kinetic study is reported for the reaction of the anionic nucleophiles OH-, CN-, and N 3 - with aryl benzoates containing substituents on the benzoyl as well as the aryloxy moiety, in 80 mol % H2O - 20 mol % dimethyl sulfoxide at 25.0 degrees C. Hammett log k vs sigma plots for these systems are consistently nonlinear. However, a possible traditional explanation in terms of a mechanism involving a tetrahedral intermediate with curvature resulting from a change in rate-determining step is considered but rejected. The proposed explanation involves ground-state stabilization through resonance interaction between the benzoyl substituent and the electrophilic carbonyl center in the two-stage mechanism. Accordingly, the data are nicely accommodated on the basis of the Yukawa-Tsuno equation, which gives linear plots for all three nuceophiles. Literature reports of the mechanism of acyl transfer processes are reconsidered in this light.

Topical Vehicle Formulations in the Treatment of Acne.

PubMed

Hoffman, Lauren K; Bhatia, Neal; Zeichner, Joshua; Kircik, Leon H

2018-06-01

Topical treatment is the mainstay of acne therapy. The most commonly prescribed topical medications for acne include benzoyl peroxide, clindamycin, and retinoids. Despite their effectiveness in treating mild to moderate acne vulgaris, these topical medications are found to be irritating, and are historically associated with poor tolerability and diminished patient adherence. Thus, choosing the right formulation that will be effective and well tolerated is essential. Novel formulations that optimize drug concentration and utilize improved delivery vehicles have helped to enhance the tolerability and efficacy, and allow for less frequent application or co-application of drugs that were previously considered incompatible. This article will review the goals of topical therapy for the treatment of acne, in addition to common therapies and their challenges. Advanced formulations and combination formulations of benzoyl peroxide, clindamycin, and tretinoin will also be discussed. J Drugs Dermatol. 2018;17(6 Suppl):s6-10.

Management strategies for acne vulgaris

PubMed Central

Whitney, Kristen M; Ditre, Chérie M

2011-01-01

Clinical question: What are the most effective treatment(s) for mild, moderate, severe, and hormonally driven acne? Results: Mild acne responds favorably to topical treatments such as benzoyl peroxide, salicylic acid, and a low-dose retinoid. Moderate acne responds well to combination therapy comprising-topical benzoyl peroxide, antibiotics, and/or retinoids, as well as oral antibiotics in refractory cases and oral contraceptive pills for female acne patients. Severe nodulocystic acne vulgaris responds best to oral isotretinoin therapy. In female patients with moderate to severe acne, facial hair, loss of scalp hair and irregular periods, polycystic ovarian syndrome should be considered and appropriate treatment with hormonal modulation given. Adjunctive procedures can also be considered for all acne patients. Implementation: Pitfalls to avoid when treating acne: treatment of acne in women of child-bearing age; familiarization of all acne treatments in order to individualize management for patients; indications for specialist referral. PMID:21691566

Effects of a cocaine hydrolase engineered from human butyrylcholinesterase on metabolic profile of cocaine in rats.

PubMed

Chen, Xiabin; Zheng, Xirong; Zhou, Ziyuan; Zhan, Chang-Guo; Zheng, Fang

2016-11-25

Accelerating cocaine metabolism through enzymatic hydrolysis at cocaine benzoyl ester is recognized as a promising therapeutic approach for cocaine abuse treatment. Our more recently designed A199S/F227A/S287G/A328W/Y332G mutant of human BChE, denoted as cocaine hydrolase-3 (CocH3), has a considerably improved catalytic efficiency against cocaine and has been proven active in blocking cocaine-induced toxicity and physiological effects. In the present study, we have further characterized the effects of CocH3 on the detailed metabolic profile of cocaine in rats administrated intravenously (IV) with 5 mg/kg cocaine, demonstrating that IV administration of 0.15 mg/kg CocH3 dramatically changed the metabolic profile of cocaine. Without CocH3 administration, the dominant cocaine-metabolizing pathway in rats was cocaine methyl ester hydrolysis to benzoylecgonine (BZE). With the CocH3 administration, the dominant cocaine-metabolizing pathway in rats became cocaine benzoyl ester hydrolysis to ecgonine methyl ester (EME), and the other two metabolic pathways (i.e. cocaine methyl ester hydrolysis to BZE and cocaine oxidation to norcocaine) became insignificant. The CocH3-catalyzed cocaine benzoyl ester hydrolysis to EME was so efficient such that the measured maximum blood cocaine concentration (∼38 ng/ml) was significantly lower than the threshold blood cocaine concentration (∼72 ng/ml) required to produce any measurable physiological effects. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Biocatalytic synthesis, antimicrobial properties and toxicity studies of arginine derivative surfactants.

PubMed

Fait, M Elisa; Garrote, Graciela L; Clapés, Pere; Tanco, Sebastian; Lorenzo, Julia; Morcelle, Susana R

2015-07-01

Two novel arginine-based cationic surfactants were synthesized using as biocatalyst papain, an endopeptidase from Carica papaya latex, adsorbed onto polyamide. The classical substrate N (α)-benzoyl-arginine ethyl ester hydrochloride for the determination of cysteine and serine proteases activity was used as the arginine donor, whereas decyl- and dodecylamine were used as nucleophiles for the condensation reaction. Yields higher than 90 and 80 % were achieved for the synthesis of N (α)-benzoyl-arginine decyl amide (Bz-Arg-NHC10) and N (α)-benzoyl-arginine dodecyl amide (Bz-Arg-NHC12), respectively. The purification process was developed in order to make it more sustainable, by using water and ethanol as the main separation solvents in a single cationic exchange chromatographic separation step. Bz-Arg-NHC10 and Bz-Arg-NHC12 proved antimicrobial activity against both Gram-positive and Gram-negative bacteria, revealing their potential use as effective disinfectants as they reduced 99 % the initial bacterial population after only 1 h of contact. The cytotoxic effect towards different cell types of both arginine derivatives was also measured. Bz-Arg-NHCn demonstrated lower haemolytic activity and were less eye-irritating than the commercial cationic surfactant cetrimide. A similar trend could also be observed when cytotoxicity was tested on hepatocytes and fibroblast cell lines: both arginine derivatives were less toxic than cetrimide. All these properties would make the two novel arginine compounds a promising alternative to commercial cationic surfactants, especially for their use as additives in topical formulations.

Fixed-Dose Combination Gel of Adapalene and Benzoyl Peroxide plus Doxycycline 100 mg versus Oral Isotretinoin for the Treatment of Severe Acne: Efficacy and Cost Analysis

PubMed Central

Penna, Pete; Meckfessel, Matthew H.; Preston, Norman

2014-01-01

Background Acne vulgaris is a chronic skin disease with a high prevalence. Left untreated or inadequately treated, acne vulgaris can lead to psychological and physical scarring, as well as to unnecessary medical expenses. Oral isotretinoin is an effective treatment for severe resistant nodular and conglobate acne vulgaris. A regimen consisting of a fixed-dose combination of adapalene and benzoyl peroxide gel, 0.1%/2.5% (A-BPO) with oral doxycycline 100 mg (A-BPO/D) has been demonstrated to be efficacious and well tolerated in patients with severe acne and may be an alternative to oral isotretinoin for some patients with severe acne. Objective The objective of this analysis was to compare the relative efficacy and associated costs of A-BPO/D versus oral isotretinoin. Methods In this analysis, comparisons of relative efficacy were made using previously published studies involving similar patient populations with severe acne that warrant the use of oral isotretinoin. The pricing for oral doxycycline and oral isotretinoin was estimated based on the maximum allowable cost from 9 states, and the pricing for A-BPO was calculated as the range between the average wholesale price and the wholesale acquisition cost. For this analysis, 2 treatment models were generated to compare costs: (1) a basic treatment model that examined the costs of an initial regimen of either A-BPO/D or oral isotretinoin without considering probable outcomes, and (2) a long-term model that factored in likely treatment outcomes and subsequent treatments into associated costs. The basic treatment model assumed that patients would be prescribed a single regimen of A-BPO/D for 12 weeks or oral isotretinoin for 20 weeks. The long-term model considered the probability of each treatment successfully managing patients' acne, as well as likely additional regimens of A-BPO monotherapy or an additional regimen of oral isotretinoin. As a result of different treatment durations, the costs for each treatment were

76 FR 36307 - Guidance for Industry on Topical Acne Drug Products for Over-the-Counter Human Use-Revision of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-22

... the monograph (75 FR 9767, March 4, 2010) (final rule). The guidance describes the requirements of the... products marketed under the monograph (i.e., products that contain any of the active ingredients permitted under the OTC topical acne drug monograph, including benzoyl peroxide, resorcinol, resorcinol...

Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

USDA-ARS?s Scientific Manuscript database

Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey products

USDA-ARS?s Scientific Manuscript database

Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

METHOD OF PREPARING COMPLEXES OF PLUTONIUM WITH DIKETONES

DOEpatents

Dixon, J.S.; Katz, J.J.; Orlemann, E.F.

1961-06-20

A process is described for sepsrating Pu from an aqueous alkaline solution by either precipitating with a beta -diketone or extracting into a solution of the beta -dixetone in an organic water-immiscible solvent. Acetyl acetone and benzoyl acetone are the beta -diketones used.

Enantioselective synthesis of L-(-)-4- boronophenylalanine (L-BPA)

DOEpatents

Samsel, Edward G.

1992-01-01

A method of making substantially pure L-BPA is disclosed. The method includes the steps of reacting 4-bromobenzaldehyde with ethylene glycol to form 4-bromobenzaldehyde ethylene glycol acetal, sequentially reacting 4-bromobenzaldehyde ethyleneglycol acetal with Mg to produce the Grignard reagent and thereafter reacting with tributyl borate and then converting to an acid environment to form 4-boronobenzaldehyde, reacting 4-boronobenzaldehyde with diethanol amine to form 4-boronobenzaldehyde diethanolamine ester, condensing the 4-boronobenzaldehyde diethanolamine ester with 2-phenyl-2-oxazolin-5-one to form an azlactone, reacting the azlactone with an alkali metal hydroxide to form z-.alpha.-benzoylamino-4-boronocinnamic acid, asymmetrically hydrogenating the z-.alpha.-benzoylamino-4-boronocinnamic acid in the presence of a catalyst of a cheltate complex of rhodium (I) with chiral bisphosphines to form L-(+)-N-benzoyl-4-boronophenylalanine, and thereafter acidifying the L-(+)-N-benzoyl-4-boronophenylalanine in an organic medium to produce L-BPA.

Enantioselective synthesis of L-(-)-4- boronophenylalanine (L-BPA)

DOEpatents

Samsel, E.G.

1992-10-20

A method of making substantially pure L-BPA is disclosed. The method includes the steps of reacting 4-bromobenzaldehyde with ethylene glycol to form 4-bromobenzaldehyde ethylene glycol acetal, sequentially reacting 4-bromobenzaldehyde ethyleneglycol acetal with Mg to produce the Grignard reagent and thereafter reacting with tributyl borate and then converting to an acid environment to form 4-boronobenzaldehyde, reacting 4-boronobenzaldehyde with diethanol amine to form 4-boronobenzaldehyde diethanolamine ester, condensing the 4-boronobenzaldehyde diethanolamine ester with 2-phenyl-2-oxazolin-5-one to form an azlactone, reacting the azlactone with an alkali metal hydroxide to form z-[alpha]-benzoylamino-4boronocinnamic acid, asymmetrically hydrogenating the z-[alpha]-benzoylamino-4-boronocinnamic acid in the presence of a catalyst of a cheltate complex of rhodium (I) with chiral bisphosphines to form L-(+)-N-benzoyl-4-boronophenylalanine, and thereafter acidifying the L-(+)-N-benzoyl-4-boronophenylalanine in an organic medium to produce L-BPA. 3 figs.

Discovery and evaluation of a series of 3-acylindole imidazopyridine platelet-activating factor antagonists.

PubMed

Curtin, M L; Davidsen, S K; Heyman, H R; Garland, R B; Sheppard, G S; Florjancic, A S; Xu, L; Carrera, G M; Steinman, D H; Trautmann, J A; Albert, D H; Magoc, T J; Tapang, P; Rhein, D A; Conway, R G; Luo, G; Denissen, J F; Marsh, K C; Morgan, D W; Summers, J B

1998-01-01

Studies conducted with the goal of discovering a second-generation platelet-activating factor (PAF) antagonist have identified a novel class of potent and orally active antagonists which have high aqueous solubility and long duration of action in animal models. The compounds arose from the combination of the lipophilic indole portion of Abbott's first-generation PAF antagonist ABT-299 (2) with the methylimidazopyridine heterocycle moiety of British Biotechnology's BB-882 (1) and possess the positive attributes of both of these clinical candidates. Structure-activity relationship (SAR) studies indicated that modification of the indole and benzoyl spacer of lead compound 7b gave analogues that were more potent, longer-lived, and bioavailable and resulted in the identification of 1-(N, N-dimethylcarbamoyl)-4-ethynyl-3-[3-fluoro-4-[(1H-2-methylimidazo[4,5-c] pyrid-1-yl)methyl]benzoyl]indole hydrochloride (ABT-491, 22 m.HCl) which has been evaluated extensively and is currently in clinical development.

Prevention and Reduction of Atrophic Acne Scars with Adapalene 0.3%/Benzoyl Peroxide 2.5% Gel in Subjects with Moderate or Severe Facial Acne: Results of a 6-Month Randomized, Vehicle-Controlled Trial Using Intra-Individual Comparison.

PubMed

Dréno, Brigitte; Bissonnette, Robert; Gagné-Henley, Angélique; Barankin, Benjamin; Lynde, Charles; Kerrouche, Nabil; Tan, Jerry

2018-04-01

Very few clinical trials have investigated the effect of topical acne treatment on scarring. Our objective was to evaluate the efficacy of adapalene 0.3%/benzoyl peroxide 2.5% gel (A0.3/BPO2.5) in atrophic acne scar formation in patients with acne. In this multicenter, randomized, investigator-blinded, vehicle-controlled study, subjects with moderate or severe facial acne (Investigator's Global Assessment [IGA] score 3 or 4; ≥ 25 inflammatory lesions; ten or more atrophic acne scars) applied A0.3/BPO2.5 or vehicle daily per half face for 24 weeks. Subjects with acne requiring systemic treatment were excluded. Assessments included investigator atrophic acne scar count, Scar Global Assessment (SGA), acne lesion count, IGA, skin roughness and skin texture, subject self-assessment of clinical acne-related scars and satisfaction questionnaire, tolerability, and safety. Included subjects (n = 67) had mainly moderate acne (92.5% IGA 3); mean scores at baseline were approximately 40 acne lesions and 12 scars per half face. By week 24, the change from baseline in total scar count was - 15.5% for A0.3/BPO2.5 versus  + 14.4% for vehicle (approximately 30% difference), with a mean of 9.5 scars versus 13.3 per half face, respectively (p < 0.0001). For SGA at week 24, a total of 32.9% with A0.3/BPO2.5 versus 16.4% with vehicle (p < 0.01) were clear/almost clear. Inflammatory acne lesions decreased by 86.7% for A0.3/BPO2.5 versus 57.9% for vehicle (p < 0.0001), and 64.2 versus 19.4% of subjects, respectively, were IGA clear/almost clear (p < 0.0001) at week 24. Treatment-related AEs were reported by 20.9% for A0.3/BPO2.5 versus 9% for vehicle side, most commonly skin irritation (14.9 vs. 6%, respectively). Topical A0.3/BPO2.5 prevented and reduced atrophic scar formation. Scar count increased with vehicle (+ 14.4%) but decreased with A0.3/BPO2.5 (- 15.5%) over 24 weeks. ClinicalTrials.gov identifier NCT02735421.

Constituents of cultivated Agaricus blazei.

PubMed

Ueguchi, Yumi; Matsunami, Katsuyoshi; Otsuka, Hideaki; Kondo, Kazunari

2011-04-01

Two phenylhexane derivatives (1, 2), benzoylergostane (3), N-benzoyl-L-leucine methyl ester (4), two known ergostanes, and highly degraded incisterol were isolated from fruit bodies of Agaricus blazei. Compound 3 exhibited strong cytotoxicity toward HepG2 cells (IC(50) = 6.0 ± 0.33 μM).

Solid-phase synthesis of the nucleopeptide fragment H-Asp-Ser[pAAAGTAAGCC]-Glu-OH from the nucleoprotein of Bacillus subtilis phage phi 29.

PubMed Central

Dreef-Tromp, C M; van der Maarel, J C; van den Elst, H; van der Marel, G A; van Boom, J H

1992-01-01

The naturally occurring DNA-nucleopeptide H-Asp-Ser[5'-pAAAGTAAGCC-3']-Glu-OH was prepared via a solid-phase phosphite triester approach using N-2-(tert-butyldiphenylsilyloxymethyl)benzoyl protected nucleosides. The oligonucleotide was linked via the extremely base-labile oxalyl ester anchor to the solid support. PMID:1508685

Direct interactions between the coiled-coil tip of DksA and the trigger loop of RNA polymerase mediate transcriptional regulation

USDA-ARS?s Scientific Manuscript database

E. coli DksA is in a class of transcription factors that modify RNA polymerase (RNAP) in all three kingdoms of life. DksA potentiates the effects of the global regulator ppGpp and the initiating NTP, controlling transcription initiation without binding to DNA. Incorporating benzoyl-phenylalanine (Bp...

PKA and Epac synergistically inhibit smooth muscle cell proliferation

PubMed Central

Hewer, Richard C.; Sala-Newby, Graciela B.; Wu, Yih-Jer; Newby, Andrew C.; Bond, Mark

2011-01-01

Cyclic AMP signalling promotes VSMC quiescence in healthy vessels and during vascular healing following injury. Cyclic AMP inhibits VSMC proliferation via mechanisms that are not fully understood. We investigated the role of PKA and Epac signalling on cAMP-induced inhibition of VSMC proliferation. cAMP-mediated growth arrest was PKA-dependent. However, selective PKA activation with 6-Benzoyl-cAMP did not inhibit VSMC proliferation, indicating a requirement for additional pathways. Epac activation using the selective cAMP analogue 8-CPT-2′-O-Me-cAMP, did not affect levels of hyperphosphorylated Retinoblastoma (Rb) protein, a marker of G1-S phase transition, or BrdU incorporation, despite activation of the Epac-effector Rap1. However, 6-Benzoyl-cAMP and 8-CPT-2′-O-Me-cAMP acted synergistically to inhibit Rb-hyperphosphorylation and BrdU incorporation, indicating that both pathways are required for growth inhibition. Consistent with this, constitutively active Epac increased Rap1 activity and synergised with 6-Benzoyl-cAMP to inhibit VSMC proliferation. PKA and Epac synergised to inhibit phosphorylation of ERK and JNK. Induction of stellate morphology, previously associated with cAMP-mediated growth arrest, was also dependent on activation of both PKA and Epac. Rap1 inhibition with Rap1GAP or siRNA silencing did not negate forskolin-induced inhibition of Rb-hyperphosphorylation, BrdU incorporation or stellate morphology. This data demonstrates for the first time that Epac synergises with PKA via a Rap1-independent mechanism to mediate cAMP-induced growth arrest in VSMC. This work highlights the role of Epac as a major player in cAMP-dependent growth arrest in VSMC. PMID:20971121

The fate of benzoic acid in various species

PubMed Central

Bridges, J. W.; French, M. R.; Smith, R. L.; Williams, R. T.

1970-01-01

1. The urinary excretion of orally administered [14C]benzoic acid in man and 20 other species of animal was examined. 2. At a dose of 50mg/kg, benzoic acid was excreted by the rodents (rat, mouse, guinea pig, golden hamster, steppe lemming and gerbil), the rabbit, the cat and the capuchin monkey almost entirely as hippuric acid (95–100% of 24h excretion). 3. In man at a dose of 1mg/kg and the rhesus monkey at 20mg/kg benzoic acid was excreted entirely as hippuric acid. 4. At 50mg/kg benzoic acid was excreted as hippuric acid to the extent of about 80% of the 24h excretion in the squirrel monkey, pig, dog, ferret, hedgehog and pigeon, the other 20% being found as benzoyl glucuronide and benzoic acid, the latter possibly arising by decomposition of the former. 5. On increasing the dose of benzoic acid to 200mg/kg in the ferret, the proportion of benzoyl glucuronide excreted increased and that of hippuric acid decreased. This did not occur in the rabbit, which excreted 200mg/kg almost entirely as hippuric acid. It appears that the hedgehog and ferret are like the dog in respect to their metabolism of benzoic acid. 6. The Indian fruit bat produced only traces of hippuric acid and possibly has a defect in the glycine conjugation of benzoic acid. The main metabolite in this animal (dose 50mg/kg) was benzoyl glucuronide. 7. The chicken, side-necked turtle and gecko converted benzoic acid mainly into ornithuric acid, but all three species also excreted smaller amounts of hippuric acid. PMID:4990586

Synthesis, characterization, molecular docking and in vitro antimalarial properties of new carboxamides bearing sulphonamide.

PubMed

Ugwu, D I; Okoro, U C; Ukoha, P O; Okafor, S; Ibezim, A; Kumar, N M

2017-07-28

Sulphonamides and carboxamides have shown large number of pharmacological properties against different types of diseases among which is malaria. Twenty four new carboxamide derivatives bearing benzenesulphonamoyl alkanamides were synthesized and investigated for their in silico and in vitro antimalarial and antioxidant properties. The substituted benzenesulphonyl chlorides (1a-c) were treated with various amino acids (2a-h) to obtain the benzenesulphonamoyl alkanamides (3a-x) which were subsequently treated with benzoyl chloride to obtain the N-benzoylated derivatives (5a-f, i-n and q-v). Further reactions of the N-benzoylated derivatives or proline derivatives with 4-aminoacetophenone (6) using boric acid as a catalyst gave the sulphonamide carboxamide derivatives (7a-x) in excellent yields. The in vitro antimalarial studies showed that all synthesized compounds had antimalarial property. Compound 7k, 7c, 7l, 7s, and 7j had mean MIC value of 0.02, 0.03, 0.05, 0.06 and 0.08 μM respectively comparable with chloroquine 0.06 μM. Compound 7c was the most potent antioxidant agent with IC 50 value of 0.045 mM comparable with 0.34 mM for ascorbic acid. In addition to the successful synthesis of the target molecules using boric acid catalysis, the compounds were found to have antimalarial and antioxidant activities comparable with known antimalarial and antioxidant drugs. The class of compounds reported herein have the potential of reducing oxidative stress arising from malaria parasite and chemotherapeutic agent used in the treatment of malaria. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Post Accident Procedures for Chemicals and Propellants.

DTIC Science & Technology

1982-09-01

benzoyl derivatives, saccharin, medicines, dyes and perfumes ; as a source of toluene diiscyanates (polyurethane resins); in explosives (TNT...menasi ene piC hh, etri Sin io. pr-- -1 ra inqapparatus Fire Ctiiifnltnelnestenlndlesn 617 9gnili Tsnsp-eeteee 914*F q.I Ni..th ’It iha. A.. dii ~e iha

21 CFR 172.814 - Hydroxylated lecithin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... whereby the separated fatty acid fraction of the resultant product has an acetyl value of 30 to 38: (1) With hydrogen peroxide, benzoyl peroxide, lactic acid, and sodium hydroxide. (2) With hydrogen peroxide, acetic acid, and sodium hydroxide. (b) It is used or intended for use, in accordance with good...

Thermomechanical pulp fiber surface modification for enhancing the interfacial adhesion with polypropylene

Treesearch

Sangyeob Lee; Todd F. Shupe; Leslie H. Groom; Chung Y. Hse

2007-01-01

Chemical coupling on the thermomechanical pulp (TMP) fiber improved tensile strength of the TMP fiber handsheet and isotactic polypropylene film laminates (TPL). For the maleic anhydride W) with benzoyl peroxide (BPO)a an initiator, tensile strength increaded 52: with the TMP fiber treatment over untreated laminates. The optimum strength properties were obtained with...

Cyclohexanecarboxyl-Coenzyme A (CoA) and Cyclohex-1-ene-1-Carboxyl-CoA Dehydrogenases, Two Enzymes Involved in the Fermentation of Benzoate and Crotonate in Syntrophus aciditrophicus

PubMed Central

Kung, Johannes W.; Seifert, Jana; von Bergen, Martin

2013-01-01

The strictly anaerobic Syntrophus aciditrophicus is a fermenting deltaproteobacterium that is able to degrade benzoate or crotonate in the presence and in the absence of a hydrogen-consuming partner. During growth in pure culture, both substrates are dismutated to acetate and cyclohexane carboxylate. In this work, the unknown enzymes involved in the late steps of cyclohexane carboxylate formation were studied. Using enzyme assays monitoring the oxidative direction, a cyclohex-1-ene-1-carboxyl-CoA (Ch1CoA)-forming cyclohexanecarboxyl-CoA (ChCoA) dehydrogenase was purified and characterized from S. aciditrophicus and after heterologous expression of its gene in Escherichia coli. In addition, a cyclohexa-1,5-diene-1-carboxyl-CoA (Ch1,5CoA)-forming Ch1CoA dehydrogenase was characterized after purification of the heterologously expressed gene. Both enzymes had a native molecular mass of 150 kDa and were composed of a single, 40- to 45-kDa subunit; both contained flavin adenine dinucleotide (FAD) as a cofactor. While the ChCoA dehydrogenase was competitively inhibited by Ch1CoA in the oxidative direction, Ch1CoA dehydrogenase further converted the product Ch1,5CoA to benzoyl-CoA. The results obtained suggest that Ch1,5CoA is a common intermediate in benzoate and crotonate fermentation that serves as an electron-accepting substrate for the two consecutively operating acyl-CoA dehydrogenases characterized in this work. In the case of benzoate fermentation, Ch1,5CoA is formed by a class II benzoyl-CoA reductase; in the case of crotonate fermentation, Ch1,5CoA is formed by reversing the reactions of the benzoyl-CoA degradation pathway that are also employed during the oxidative (degradative) branch of benzoate fermentation. PMID:23667239

N-benzoylimido complexes of palladium. Synthesis, structural characterisation and structure-reactivity relationship.

PubMed

Besenyei, Gábor; Párkányi, László; Szalontai, Gábor; Holly, Sándor; Pápai, Imre; Keresztury, Gábor; Nagy, Andrea

2004-07-07

Benzoyl azides, ArC(O)N3, 2, (Ar = phenyl or substituted phenyl), react with [Pd2Cl2(dppm)2], 1, [dppm = bis(diphenylphosphino)methane] with the formation of novel [Pd2Cl2(mu-NC(O)Ar)(dppm)2], 3, benzoylnitrene complexes that were structurally characterised by multinuclear magnetic resonance and IR spectroscopy and, in several instances, by single crystal X-ray diffraction. As shown by crystallographic studies, the C2P4Pd2 rings adopt extended twist-boat conformations with methylene groups bending towards the bridging benzoylimido moieties. X-ray diffraction studies have revealed the chiral nature of the imido complexes, the chiral element being the propeller-like C2P4Pd2 ring. Structural data accumulated on complexes 3 such as short C-N distances (1.32 A), elongated C=O bonds (1.30 A) as well as the outstandingly high barrier to internal rotation around the N-C(O) linkage (88.3 kJ mol(-1)) are in line with extensive ppi-ppi interaction between the bridging nitrogen and the carbonyl carbon atoms. Theoretical calculations indicate an electron shift from the dimer towards the apical nitrogen atom, which, in turn, facilitates the donation of electrons towards the carbonyl moiety. To elucidate the structure-reactivity relationship of benzoyl azides towards 1, crystallographic and solution IR spectroscopic studies were carried out on a series of para-substituted benzoyl azides. The reaction obeys the Hammett equation. The large positive value of the reaction constant indicates that the azides act as electrophiles in the reaction studied. The enhanced reactivity of 2-nitrobenzoyl azide has been attributed to a decreased conjugation of the phenyl and carbonyl moieties in this reagent.

Effects of silane on the properties of wood-plastic composites with polyethylene-polypropylene blends as matrices

Treesearch

Craig M. Clemons; Ronald C. Sabo; Michael L. Kaland; Kolby C. Hirth

2011-01-01

The influence of 3-(trimethoxysilyl)propyl methacrylate and benzoyl peroxide on gel content, crystallinity, and mechanical performance of unfilled PP-PE blends, and their composites with wood was investigated. All materials were compounded in a twin screw extruder and then injection molded. Specimens were then exposed to high-humidity and elevated temperature in a...

Maleated polypropylene film and wood fiber handsheet laminates

Treesearch

Sangyeob Lee; Todd F. Shupe; Leslie H. Groom; Chung Y. Hse

2008-01-01

The grafting effect of maleic anhydride (MA) as an interfacial bonding agent and its influence on the tensile strength properties of thermomechanical pulp handsheet-isotactic polypropylene (iPP) film laminates was studied. For the MA treated with benzoyl peroxide (BPO) as an initiator, tensile strength properties increased 76% with PP film over untreated laminates. The...

A Fast, Accurate and Sensitive GC-FID Method for the Analyses of Glycols in Water and Urine

NASA Technical Reports Server (NTRS)

Kuo, C. Mike; Alverson, James T.; Gazda, Daniel B.

2017-01-01

Glycols, specifically ethylene glycol and 1,2-propanediol, are some of the major organic compounds found in the humidity condensate samples collected on the International Space Station. The current analytical method for glycols is a GC/MS method with direct sample injection. This method is simple and fast, but it is not very sensitive. Reporting limits for ethylene glycol and 1,2-propanediol are only 1 ppm. A much more sensitive GC/FID method was developed, in which glycols were derivatized with benzoyl chloride for 10 minutes before being extracted with hexane. Using 1,3-propanediol as an internal standard, the detection limits for the GC/FID method was determined to be 50 ppb and the analysis only takes 7 minutes. Data from the GC/MS and the new GC/FID methods shows excellent agreement with each other. Factors affecting the sensitivity, including sample volume, NaOH concentration and volume, volume of benzoyl chloride, reaction time and temperature, were investigated. Interferences during derivatization and possible method to reduce interferences were also investigated.

A double-blind investigation of the potential systemic absorption of isotretinoin, when combined with chemical sunscreens, following topical application to patients with widespread acne of the face and trunk.

PubMed

Cunliffe, W J; Glass, D; Goode, K; Stables, G I; Boorman, G C

2001-01-01

This study assessed the systemic absorption of isotretinoin and its metabolites, during a 4-week application of a cream containing 0.1% isotretinoin and chemical sunscreens, compared with a 4% benzoyl peroxide cream, in patients with acne on the face and trunk. Blood was drawn at weeks 0, 1, 2, 3 and 4 and at 96 h post-treatment. Plasma levels of isotretinoin (13-cis-retinoic acid) and tretinoin (all-trans-retinoic acid) were quantified by liquid chromatography with tandem mass spectrometry and the presence of their combined 4-oxo metabolites were monitored from the peak area ratios observed. The isotretinoin group showed no statistically or clinically significant increases in plasma retinoid levels and mean levels did not exceed +/-2 SD of the mean pre-treatment values, indicating that endogenous levels were not being exceeded. No significant differences were detected between the isotretinoin group and the 4% benzoyl peroxide group. These findings indicated that retinoid absorption from a cream containing 0.1% isotretinoin and chemical sunscreens was clinically insignificant, when applied to patients with widespread acne.

Multistimuli responsive organogels based on a reactive azobenzene gelator.

PubMed

Yang, Runmiao; Peng, Shuhua; Hughes, Timothy C

2014-04-07

A reactive azobenzene based super organogelator was found to rapidly and reversibly transform a range of hydrophobic solvents from gels to solutions upon changes in temperature, light and shear force. More specifically they formed gels at concentrations as low as 0.08 wt%. Upon heating, exposure to UV light, or application of shear, the π-π bonding was disrupted which resulted in a rapid drop of both modulus and viscosity. This was confirmed by (1)H NMR, SAXS, and rheological measurements. Although many examples of organogelators are known in the literature, this is the first time that a reactive group, a benzoyl chloride, has been incorporated in a supramolecular organogel structure. Moreover, this group is available for subsequent synthetic modifications. The presence of benzoyl chloride groups showed a remarkable effect on the formation and properties of the gels. Compared with other approaches, this strategy is advantageous in terms of structural design since it not only produces a multi-responsive soft material but also allows facile modifications which may expand the applications of organogels to other fields.

Lung tumor induction in strain A mice with benzotrichloride.

PubMed

Stoner, G D; You, M; Morgan, M A; Superczynski, M J

1986-11-01

Benzotrichloride (BTC) is used in the synthesis of benzoyl chloride and benzoyl peroxide. Epidemiological data suggest that BTC is a human lung carcinogen. In the present study, BTC was evaluated for its ability to induce lung adenomas in strain A/J mice. Four groups of 15 male and 15 female A/J mice were injected i.p. with either tricaprylin or BTC in tricaprylin three times a week for 8 weeks. BTC groups received doses totaling 1440 mg/kg, 719 mg/kg or 287 mg/kg. The mean number of lung tumors per mouse was 127 87 +/- 5.81, 43 +/- 2.44, and 17.73 +/- 1.09 in the groups treated with either 1440 mg/kg, 719 mg/kg, or 287 mg/kg, respectively. Tricaprylin-vehicle controls had a mean number of 0.46 +/- 0.15 lung tumors per mouse. Therefore, BTC produced a significant (P less than 0.001) and dose-related increase in the lung tumor response when compared to tricaprylin controls and is a potent carcinogen in the strain A mouse lung tumor bioassay.

Blockade of human P2X7 receptor function with a monoclonal antibody.

PubMed

Buell, G; Chessell, I P; Michel, A D; Collo, G; Salazzo, M; Herren, S; Gretener, D; Grahames, C; Kaur, R; Kosco-Vilbois, M H; Humphrey, P P

1998-11-15

A monoclonal antibody (MoAb) specific for the human P2X7 receptor was generated in mice. As assessed by flow cytometry, the MoAb labeled human blood-derived macrophage cells natively expressing P2X7 receptors and cells transfected with human P2X7 but not other P2X receptor types. The MoAb was used to immunoprecipitate the human P2X7 receptor protein, and in immunohistochemical studies on human lymphoid tissue, P2X7 receptor labeling was observed within discrete areas of the marginal zone of human tonsil sections. The antibody also acted as a selective antagonist of human P2X7 receptors in several functional studies. Thus, whole cell currents, elicited by the brief application of 2',3'-(4-benzoyl)-benzoyl-ATP in cells expressing human P2X7, were reduced in amplitude by the presence of the MoAb. Furthermore, preincubation of human monocytic THP-1 cells with the MoAb antagonized the ability of P2X7 agonists to induce the release of interleukin-1beta.

Laser photolysis studies of ω-bond dissociation in aromatic carbonyls with a C-C triple bond stimulated by triplet sensitization.

PubMed

Yamaji, Minoru; Horimoto, Ami; Marciniak, Bronislaw

2017-07-14

We have prepared three types of carbonyl compounds, benzoylethynylmethyl phenyl sulfide (2@SPh), (p-benzoyl)phenylethynylmethyl phenyl sulfide (3@SPh) and p-(benzoylethynyl)benzyl phenyl sulfide (4@SPh) with benzoyl and phenylthiylmethyl groups, which are interconnected with a C-C triple bond and a phenyl ring. Laser flash photolysis of 3@SPh and 4@SPh in acetonitrile provided the transient absorption spectra of the corresponding triplet states where no chemical reactions were recognized. Upon laser flash photolysis of 2@SPh, the absorption band due to the phenylthiyl radical (PTR) was obtained, indicating that the C-S bond cleaved in the excited state. Triplet sensitization of these carbonyl compounds using acetone and xanthone was conducted using laser photolysis techniques. The formation of triplet 3@SPh was seen in the transient absorption, whereas the PTR formation was observed for 2@SPh and 4@SPh, indicating that the triplet states were reactive for the C-S bond dissociation. The C-S bond dissociation mechanism for 4@SPh upon triplet sensitization is discussed in comparison with those for 2@SPh and 3@SPh.

Synthesis of fagopyritols A1 and B1 from D-chiro-inositol.

PubMed

Cid, M Belén; Alfonso, Francisco; Martín-Lomas, Manuel

2004-09-13

Fagopyritol A1 (3-O-alpha-d-galactopyranosyl-d-chiro-inositol) and fagopyritol B1 (2-O-alpha-d-galactopyranosyl-d-chiro-inositol) have been synthesized by glycosylation of the diequatorial diol 1,4,5,6-tetra-O-benzoyl-d-chiro-inositol, readily obtained from d-chiro-inositol, with 2,3,4,6-tetra-O-benzyl-d-galactopyranosyl trichloroacetimidate.

21 CFR 172.345 - Folic acid (folacin).

Code of Federal Regulations, 2011 CFR

2011-04-01

... following prescribed conditions: (a) Folic acid is the chemical N-[4-[[(2-amino-1,4-dihydro-4-oxo-6-pteridinyl)methyl]amino]benzoyl]-L-glutamic acid. (b) Folic acid meets the specifications of the “Food... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Folic acid (folacin). 172.345 Section 172.345 Food...

40 CFR 60.489 - List of chemicals produced by affected facilities.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Resorcylic acid. 69-72-7 Salicylic acid. 127-09-3 Sodium acetate. 532-32-1 Sodium benzoate. 9004-32-4 Sodium... Benzoyl chloride. 100-51-6 Benzyl alcohol. 100-46-9 Benzylamine. 120-51-4 Benzyl benzoate. 100-44-7 Benzyl... 2-ethylhexanol. 122-51-0 Ethyl orthoformate. 95-92-1 Ethyl oxalate. 41892-71-1 Ethyl sodium...

40 CFR 60.489 - List of chemicals produced by affected facilities.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Resorcylic acid. 69-72-7 Salicylic acid. 127-09-3 Sodium acetate. 532-32-1 Sodium benzoate. 9004-32-4 Sodium... Benzoyl chloride. 100-51-6 Benzyl alcohol. 100-46-9 Benzylamine. 120-51-4 Benzyl benzoate. 100-44-7 Benzyl... 2-ethylhexanol. 122-51-0 Ethyl orthoformate. 95-92-1 Ethyl oxalate. 41892-71-1 Ethyl sodium...

40 CFR 60.489 - List of chemicals produced by affected facilities.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Resorcylic acid. 69-72-7 Salicylic acid. 127-09-3 Sodium acetate. 532-32-1 Sodium benzoate. 9004-32-4 Sodium... Benzoyl chloride. 100-51-6 Benzyl alcohol. 100-46-9 Benzylamine. 120-51-4 Benzyl benzoate. 100-44-7 Benzyl... 2-ethylhexanol. 122-51-0 Ethyl orthoformate. 95-92-1 Ethyl oxalate. 41892-71-1 Ethyl sodium...

Safe Preparation of HCl and DCl for IR Spectroscopy

ERIC Educational Resources Information Center

Furlong, William R.; Grubbs, W. Tandy

2005-01-01

The widely used method of synthesizing HCl and DCl gases for infrared analysis by hydrolysis of benzoyl chloride includes a potentially dangerous final step whereby the frozen product is allowed to heat and expand into an infrared gas cell. The subsequent rapid rise in vapor pressure can "pop" open glass joints in the vacuum line and vent the…

9-Benzoyl 9-deazaguanines as potent xanthine oxidase inhibitors.

PubMed

Rodrigues, Marili V N; Barbosa, Alexandre F; da Silva, Júlia F; dos Santos, Deborah A; Vanzolini, Kenia L; de Moraes, Marcela C; Corrêa, Arlene G; Cass, Quezia B

2016-01-15

A novel potent xanthine oxidase inhibitor, 3-nitrobenzoyl 9-deazaguanine (LSPN451), was selected from a series of 10 synthetic derivatives. The enzymatic assays were carried out using an on-flow bidimensional liquid chromatography (2D LC) system, which allowed the screening¸ the measurement of the kinetic inhibition constant and the characterization of the inhibition mode. This compound showed a non-competitive inhibition mechanism with more affinity for the enzyme-substrate complex than for the free enzyme, and inhibition constant of 55.1±9.80 nM, about thirty times more potent than allopurinol. Further details of synthesis and enzymatic studies are presented herein. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ability of m-chloroperoxybenzoic acid to induce the ornithine decarboxylase marker of skin tumor promotion and inhibition of this response by gallotannins, oligomeric proanthocyanidins, and their monomeric units in mouse epidermis in vivo

Treesearch

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Steven W. Newell; Vittorio Bottari; Richard W. Hemingway; Jean-Pierre Perchellet

1995-01-01

m-Chloroperoxybenzoic acid (CPBA) was tested for its ability to induce the ornithine decarboxylase (ODC) marker of skin tumor promotion. In contrast to benzoyl peroxide, dicumyl peroxide, and 2-butanol peroxide, 5 mg of CPBA applied twice at a 72-h interval induce DOC activity at least as much as 3 µg of 12-O-tetradecanoylphorbol-13.acetate (TPA)....

Ability of m-chloroperoxybenzoic acid to induce the ornithine decarboxylase marker of skin tumor promotion and inhibition of this response by gallotannins, oligomeric proanthocyanidins, and their monomeric units in mouse epidermis in Vivo

Treesearch

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Steven W. Newell; richard W. Hemingway; Vittorio Bottari; Jean-Pierre Perchellet

1995-01-01

m-Chloroperoxybenzoic acid (CPBA) was tested for its ability to induce the ornithine decarboxylase (ODC) marker of skin tumor promotion. In contrast to benzoyl peroxide, dicumyl peroxide, and 2-butanol peroxide, 5 mg of CPBA applied twice at a 72-h interval induce ODC activity at least as much as 3 ug of 12-O-tetradecanoylphorbol-13-acetate (TPA). ODC induction peaks...

CuI/L-proline-catalyzed coupling reactions of aryl halides with activated methylene compounds.

PubMed

Xie, Xiaoan; Cai, Guorong; Ma, Dawei

2005-10-13

[reaction: see text] The arylation of ethyl acetoacetate, ethyl benzoyl acetate, and diethyl malonate under the catalysis of CuI/L-proline in DMSO proceeds smoothly at 40-50 degrees C in the presence of Cs2CO3 to provide the 2-aryl-1,3-dicarbonyl compounds in good yields. Both aryl iodides and aryl bromides are compatible with these reaction conditions.

Raman spectroscopy-based detection of chemical contaminants in food powders

NASA Astrophysics Data System (ADS)

Chao, Kuanglin; Dhakal, Sagar; Qin, Jianwei; Kim, Moon; Bae, Abigail

2016-05-01

Raman spectroscopy technique has proven to be a reliable method for qualitative detection of chemical contaminants in food ingredients and products. For quantitative imaging-based detection, each contaminant particle in a food sample must be detected and it is important to determine the necessary spatial resolution needed to effectively detect the contaminant particles. This study examined the effective spatial resolution required for detection of maleic acid in tapioca starch and benzoyl peroxide in wheat flour. Each chemical contaminant was mixed into its corresponding food powder at a concentration of 1% (w/w). Raman spectral images were collected for each sample, leveled across a 45 mm x 45 mm area, using different spatial resolutions. Based on analysis of these images, a spatial resolution of 0.5mm was selected as effective spatial resolution for detection of maleic acid in starch and benzoyl peroxide in flour. An experiment was then conducted using the 0.5mm spatial resolution to demonstrate Raman imaging-based quantitative detection of these contaminants for samples prepared at 0.1%, 0.3%, and 0.5% (w/w) concentrations. The results showed a linear correlation between the detected numbers of contaminant pixels and the actual concentrations of contaminant.

[Azelaic acid 15% gel in the treatment of acne vulgaris. Combined results of two double-blind clinical comparative studies].

PubMed

Gollnick, Harald P M; Graupe, Klaus; Zaumseil, Rolf-Peter

2004-10-01

Topical measures are still the mainstay in the therapy of mild-to-moderate acne vulgaris. Azelaic acid 20% in a cream formulation has been established as an efficacious and safe topical drug for 15 years. A new non-alcoholic hydrogel formulation containing 15% azelaic acid was clinically tested against two standard drugs--5% benzoyl peroxide (BPO) and 1% clindamycin. In two independent, randomized, blinded comparative trials 15% azelaic acid gel was clinically tested against 5% benzoyl peroxide (BPO) gel in 351 patients and against 1% clindamycin gel in 229 patients. The drugs were applied b.i.d. for 4 months. Azelaic acid 15% gel proved to be as effective as BPO and clindamycin with median % reduction of the inflamed lesion (papules and pustules) of 70%, and 71% respectively. The azelaic acid gel was well-tolerated, the side effects (local burning and irritation) were distinctly less than with BPO but more pronounced than with clindamycin. Despite these side effects, the treatment was well-accepted by the majority of patients. Azelaic acid gel is an effective topical monotherapy for mild-to-moderate acne vulgaris; its new gel form is an enrichment of acne therapy.

Bacterial Degradation of Benzoate

PubMed Central

Valderrama, J. Andrés; Durante-Rodríguez, Gonzalo; Blázquez, Blas; García, José Luis; Carmona, Manuel; Díaz, Eduardo

2012-01-01

We have studied for the first time the transcriptional regulatory circuit that controls the expression of the box genes encoding the aerobic hybrid pathway used to assimilate benzoate via coenzyme A (CoA) derivatives in bacteria. The promoters responsible for the expression of the box cluster in the β-proteobacterium Azoarcus sp., their cognate transcriptional repressor, the BoxR protein, and the inducer molecule (benzoyl-CoA) have been characterized. The BoxR protein shows a significant sequence identity to the BzdR transcriptional repressor that controls the bzd genes involved in the anaerobic degradation of benzoate. Because the boxR gene is present in all box clusters so far identified in bacteria, the BoxR/benzoyl-CoA regulatory system appears to be a widespread strategy to control this aerobic hybrid pathway. Interestingly, the paralogous BoxR and BzdR regulators act synergistically to control the expression of the box and bzd genes. This cross-regulation between anaerobic and aerobic pathways for the catabolism of aromatic compounds has never been shown before, and it may reflect a biological strategy to increase the cell fitness in organisms that survive in environments subject to changing oxygen concentrations. PMID:22303008

Benzofuran-chalcone hybrids as potential multifunctional agents against Alzheimer's disease: synthesis and in vivo studies with transgenic Caenorhabditis elegans.

PubMed

Sashidhara, Koneni V; Modukuri, Ram K; Jadiya, Pooja; Dodda, Ranga Prasad; Kumar, Manoj; Sridhar, Balasubramaniam; Kumar, Vikash; Haque, Rizwanul; Siddiqi, Mohammad Imran; Nazir, Aamir

2014-12-01

In the search for effective multifunctional agents for the treatment of Alzheimer's disease (AD), a series of novel hybrids incorporating benzofuran and chalcone fragments were designed and synthesized. These hybrids were screened by using a transgenic Caenorhabditis elegans model that expresses the human β-amyloid (Aβ) peptide. Among the hybrids investigated, (E)-3-(7-methyl-2-(4-methylbenzoyl)benzofuran-5-yl)-1-phenylprop-2-en-1-one (4 f), (E)-3-(2-benzoyl-7-methylbenzofuran-5-yl)-1-phenylprop-2-en-1-one (4 i), and (E)-3-(2-benzoyl-7-methylbenzofuran-5-yl)-1-(thiophen-2-yl)prop-2-en-1-one (4 m) significantly decreased Aβ aggregation and increased acetylcholine (ACh) levels along with the overall availability of ACh at the synaptic junction. These compounds were also found to decrease acetylcholinesterase (AChE) levels, reduce oxidative stress in the worms, lower lipid content, and to provide protection against chemically induced cholinergic neurodegeneration. Overall, the multifunctional effects of these hybrids qualify them as potential drug leads for further development in AD therapy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exciplex and excimer molecular probes: detection of conformational flip in a myo-inositol chair.

PubMed

Kadirvel, Manikandan; Arsic, Biljana; Freeman, Sally; Bichenkova, Elena V

2008-06-07

2-O-tert-Butyldimethylsilyl-4,6-bis-O-pyrenoyl-myo-inositol-1,3,5-orthoformate (6) and 2-O-tert-butyldimethylsilyl-4-O-[4-(dimethylamino)benzoyl]-6-O-pyrenoyl-myo-inositol-1,3,5-orthoacetate (10) adopt conformationally restricted unstable chairs with five axial substituents. In the symmetrical diester 6, the two pi-stacked pyrenoyl groups are electron acceptor-donor partners, giving a strong intramolecular excimer emission. In the mixed ester 10, the pyrenoyl group is the electron acceptor and the 4-(dimethylamino)benzoyl ester is the electron donor, giving a strong intramolecular exciplex emission. The conformation of the mixed ester 10 was assessed using 1H NMR spectroscopy (1H-NOESY) and computational studies. which showed the minimum inter-centroid distance between the two aromatic systems to be approximately 3.9 A. Upon addition of acid, the orthoformate/orthoacetate trigger in 6 and 10 was cleaved, which caused a switch of the conformation of the myo-inositol ring to the more stable penta-equatorial chair, leading to separation of the aromatic ester groups and loss of excimer and exciplex fluorescence, respectively. This study provides proof of principle for the development of novel fluorescent molecular probes.

Determination of heavy metal ions in vegetable samples using a magnetic metal-organic framework nanocomposite sorbent.

PubMed

Hassanpour, Akbar; Hosseinzadeh-Khanmiri, Rahim; Babazadeh, Mirzaagha; Abolhasani, Jafar; Ghorbani-Kalhor, Ebrahim

2015-01-01

This paper describes the synthesis and application of a novel magnetic metal-organic framework (MOF) [(Fe₃O₄-benzoyl isothiocyanate)/Cu₃(benzene-1,3,5-tricarboxylate)₂] to pre-concentrate trace amounts of Cd(II), Pb(II), Zn(II) and Cr(III) ions and their determination by flame atomic absorption spectrometry. A Box-Behnken design was used to find the parameters affecting the pre-concentration procedure through response surface methodology. Three factors including uptake time, amount of the magnetic sorbent and pH of the sample were selected as affecting factors in the sorption step, and four factors including type, volume and concentration of the eluent as well as the elution time were selected in the elution step for the optimisation study. The opted values were 30 mg, 10.1 min, 5.9, EDTA, 4.0 ml, 0.57 mol l(-1) EDTA solution and 13.0 min for the amount of the magnetic sorbent, uptake time, pH of the sample, type, volume, concentration of the eluent, and elution time, respectively. The limits of detection (LODs) were 0.12, 0.7, 0.16, and 0.4 ng ml(-1) for Cd(II), Pb(II), Zn(II) and Cr(III) ions, respectively. The relative standard deviations (RSDs) of the method were less than 7.2% for five separate batch experiments for the determination of 30 μg l(-1) of Cd(II), Pb(II), Zn(II) and Cr(III) ions. The sorption capacity of the [(Fe₃O₄-benzoyl isothiocyanate)/MOF] was 175 mg g(-1) for Cd(II), 168 mg g(-1) for Pb(II), 210 mg g(-1) for Zn(II) and 196 mg g(-1) for Cr(III). It was found that the magnetic MOF nanocomposite demonstrated a higher capacity compared with Fe₃O₄-benzoyl isothiocyanate. Finally, the magnetic MOF nanocomposite was successfully applied to the rapid extraction of trace amounts of the heavy metal ions from vegetable samples.

Structural comparison of complexes of methotrexate analogues with Lactobacillus casei dihydrofolate reductase by two-dimensional /sup 1/H NMR at 500 MHz

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

Hammond, S.J.; Birdsall, B.; Feeney, J.

1987-12-29

The authors have used two-dimensional (2D) NMR methods to examine complexes of Lactobacillus casei dihydrofolate reductase and methotrexate (MTX) analogues having structural modifications of the benzoyl ring and also the glutamic acid moiety. Assignments of the /sup 1/H signals in the spectra of the various complexes were made by comparison of their 2D spectra with those complexes containing methotrexate where we have previously assigned resonances from 32 of the 162 amino acid residues. In the complexes formed with the dihalomethotrexate analogues, the glutamic acid and pteridine ring moieties were shown to bind to the enzyme in a manner similar tomore » that found in the methotrexate-enzyme complex. Perturbations in /sup 1/H chemical shifts of protons in Phe-49, Leu-54, and Leu-27 and the methotrexate H7 and NMe protons were observed in the different complexes and were accounted for by changes in orientation of the benzoyl ring in the various complexes. Binding of oxidized or reduced coenzyme to the binary complexes did not result in different shifts for Leu-27, Leu-54, or Leu-19 protons, and thus, the orientation of the benzoyl ring of the methotrexate analogues is not perturbed greatly by the presence of either oxidized or reduced coenzyme. In the complex with the ..gamma..-monoamide analog, the /sup 1/H signals of assigned residues in the protein had almost identical shifts with the corresponding protons in the methotrexate-enzyme complex for all residues except His-28 and, to a lesser extent, Leu-27. This indicates that while the His-28 interaction with the MTX ..gamma..-CO/sub 2//sup -/ is no longer present in this complex with the ..gamma..-amide, there has not been a major change in the overall structure of the two complexes. This behavior contrasts to that of the ..cap alpha..-amide complex where /sup 1/H signals from protons in several amino acid residues are different compared with their values in the complex formed with methotrexate.« less

An Efficient High-performance Liquid Chromatography Combined with Electrospray Ionization Tandem Mass Spectrometry Method to Elaborate the Changes of Components Between the Raw and Processed Radix Aconitum kusnezoffii

PubMed Central

Wang, Beibei; Ji, Jiaojiao; Zhao, Shuang; Dong, Jie; Tan, Peng; Na, Shengsang; Liu, Yonggang

2016-01-01

Background: Crude radix Aconitum kusnezoffii (RAK) has great toxicity. Traditional Chinese medicine practice proved that processing may decrease its toxicity. In our previous study, we had established a new method of RAK processing (Paozhi). However, the mechanism is yet not perfect. Objective: To explore the related mechanism of processing through comparing the chemical contents. Materials and Methods: A new processing method of RAK named stoving (Hong Zhi) was used. In particular, RAK was stored at 110°C for 8 h, and then high performance liquid chromatography combined with electrospray ionization tandem mass spectrometry (HPLC-ESI-MSn) was developed for the detection of the alkaloids of the crude and processed RAK decoction pieces. Results: Thirty components of the crude RAK were discovered, among which, 23 alkaloids were identified. Meanwhile, 23 ingredients were detected in the processed RAK decoction pieces, among which, 20 alkaloids were determined yet. By comparison, eight alkaloids were found in both crude and processed RAK decoction pieces, 15 alkaloids were not found in the crude RAK, however, 10 new constituents yield after processing, which are 10-OH-hypaconine, 10-OH-mesaconine, isomer of bullatine A, 14-benzoyl-10-OH-mesaconine, 14-benzoyl-10-OH-aconine, 14-benzoyl-10-OH-hypaconine, dehydrated aconitine, 14-benzoylaconine, chuanfumine, dehydrated mesaconitine. Conclusion: The present study showed that significant change of alkaloids was detected in RAK before and after processing. Among them, the highly toxic diester alkaloids decreased and the less toxic monoester alkaloids increased. Moreover, the concentration changes significantly. HPLC-ESI-MSn are Efficient to elaborate the mechanism of reduction of toxicity and enhancement efficacy after processing. SUMMARY Stoving is a simple and effective method for the processing of radix Aconitum kusnezoffii.In the positive mode, the characteristic fragmentations of Aconitum alkaloids were obtained

An easily regenerable enzyme reactor prepared from polymerized high internal phase emulsions.

PubMed

Ruan, Guihua; Wu, Zhenwei; Huang, Yipeng; Wei, Meiping; Su, Rihui; Du, Fuyou

2016-04-22

A large-scale high-efficient enzyme reactor based on polymerized high internal phase emulsion monolith (polyHIPE) was prepared. First, a porous cross-linked polyHIPE monolith was prepared by in-situ thermal polymerization of a high internal phase emulsion containing styrene, divinylbenzene and polyglutaraldehyde. The enzyme of TPCK-Trypsin was then immobilized on the monolithic polyHIPE. The performance of the resultant enzyme reactor was assessed according to the conversion ability of Nα-benzoyl-l-arginine ethyl ester to Nα-benzoyl-l-arginine, and the protein digestibility of bovine serum albumin (BSA) and cytochrome (Cyt-C). The results showed that the prepared enzyme reactor exhibited high enzyme immobilization efficiency and fast and easy-control protein digestibility. BSA and Cyt-C could be digested in 10 min with sequence coverage of 59% and 78%, respectively. The peptides and residual protein could be easily rinsed out from reactor and the reactor could be regenerated easily with 4 M HCl without any structure destruction. Properties of multiple interconnected chambers with good permeability, fast digestion facility and easily reproducibility indicated that the polyHIPE enzyme reactor was a good selector potentially applied in proteomics and catalysis areas. Copyright © 2016 Elsevier Inc. All rights reserved.

The Role of Pancreatic Enzyme Replacement Therapy in Unresectable Pancreatic Cancer: A Prospective Cohort Study.

PubMed

Saito, Tomotaka; Hirano, Kenji; Isayama, Hiroyuki; Nakai, Yousuke; Saito, Kei; Umefune, Gyotane; Akiyama, Dai; Watanabe, Takeo; Takagi, Kaoru; Hamada, Tsuyoshi; Takahara, Naminatsu; Uchino, Rie; Mizuno, Suguru; Kogure, Hirofumi; Matsubara, Saburo; Yamamoto, Natsuyo; Tada, Minoru; Koike, Kazuhiko

2017-03-01

Although patients with pancreatic cancer (PC) are prone to exocrine pancreatic insufficiency, there are little evidence about pancreatic enzyme replacement therapy (PERT) in patients with PC, especially those receiving chemotherapy. This is a prospective consecutive observational study of PERT in patients with unresectable PC. We prospectively enrolled patients receiving chemotherapy for unresectable PC from April 2012 to February 2014 and prescribed oral pancrelipase of 48,000 lipase units per meal (pancrelipase group). N-benzoyl-tryrosyl para-aminobenzoic acid test was performed at baseline. Patients receiving chemotherapy before April 2012 were retrospectively studied as a historical cohort. Data on the nutritional markers at baseline and 16 weeks were extracted, and serial changes, defined as the ratio of markers at 16 weeks/baseline, were compared between 2 groups. A total of 91 patients (46 in the pancrelipase group and 45 in the historical cohort) were analyzed. N-benzoyl-tryrosyl para-aminobenzoic acid test was low in 94% of the pancrelipase group. Serial change in the pancrelipase group versus historical cohort was 1.01 versus 0.95 in body mass index (P < 0.001) and 1.03 versus 0.97 in serum albumin (P = 0.131). The rate of exocrine pancreatic insufficiency in unresectable PC was high, and PERT can potentially improve the nutritional status during chemotherapy.

Characterization of flavonols in cranberry (Vaccinium macrocarpon) powder.

PubMed

Vvedenskaya, Irina O; Rosen, Robert T; Guido, Jane E; Russell, David J; Mills, Kent A; Vorsa, Nicholi

2004-01-28

Flavonoids were extracted from cranberry powder with acetone and ethyl acetate and subsequently fractionated with Sephadex LH-20 column chromatography. The fraction eluted with a 60% methanol solution was composed primarily of phenolic constituents with maximum absorbance at 340 nm. A high-performance liquid chromatography procedure was developed, which resolved 22 distinct peaks with UV/vis and mass spectra corresponding to flavonol glycoside conjugates. Six new constituents not previously reported in cranberry or in cranberry products were determined through NMR spectroscopy to be myricetin-3-beta-xylopyranoside, quercetin-3-beta-glucoside, quercetin-3-alpha-arabinopyranoside, 3'-methoxyquercetin-3-alpha-xylopyranoside, quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside, and quercetin-3-O-(6' '-benzoyl)-beta-galactoside. Quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside and quercetin-3-O-(6' '-benzoyl)-beta-galactoside represent a new class of cranberry flavonol compounds with three conjugated components consisting of a flavonol, sugar, and carboxylic acid (benzoic or hydroxycinnamic acids). This is also the first report identifying quercetin-3-arabinoside in both furanose and pyranose forms in cranberry. Elucidation of specific flavonol glycosides in cranberry is significant since the specificity of the sugar moiety may play a role in the bioavailability of the flavonol glycosides in vivo.

P2X7 receptor-mediated calcium dynamics in HEK293 cells: experimental characterization and modelling approach

NASA Astrophysics Data System (ADS)

Di Garbo, A.; Alloisio, S.; Nobile, M.

2012-04-01

The P2X7 receptor (P2X7R) induces ionotropic Ca2 + signalling in different cell types. It plays an important role in the immune response and in the nervous system. Here, the mechanisms underlying intracellular Ca2 + variations evoked by 3‧-O-(4-benzoyl)benzoyl-ATP (BzATP), a potent agonist of the P2X7R, in transfected HEK293 cells, are investigated both experimentally and theoretically. We propose a minimal model of P2X7R that is capable of reproducing, qualitatively and quantitatively, the experimental data. This approach was also adopted for the P2X7R variant, which lacks the entire C-terminus tail (trP2X7R). Then we introduce a biophysical model describing the Ca2 + dynamics in HEK293. Our model gives an account of the ionotropic Ca2 + influx evoked by BzATP on the basis of the kinetics model of P2X7R. To explain the complex Ca2 + responses evoked by BzATP, the model predicted that an impairment in Ca2 + extrusion flux through the plasma membrane is a key factor for Ca2 + homeostasis in HEK293 cells.

Synthesis of guanosine and its derivatives from 5-amino-1-beta-D-ribofuranosyl-e-imidazolecarboxamide. IV. A new route to guanosine via cyanamide derivative.

PubMed Central

Yamazaki, A; Okutsu, M; Yamada, Y

1976-01-01

4-Cyanamido-5-imidazolecarboxamide (IV) was prepared by brief treatment of 5-(S-methylisothiocarbamoyl) amino-4-imidazolecarboxamide (V) with alkali. Compound VI was converted in an alkaline solution to either guanine (VII) or isoguanine (VIII), depending on the concentration of alkali. This procedure was applied to the synthesis of 2',3'-0-isopropylideneguanosine (XVI) from the riboside of 5-(N'-benzoyl-S-methylthiocarbamoyl) amino-4-imidazolecarboxamide (IX), PROviding a new route to XVI. PMID:1250702

Exploiting the CNC side chain in heterocyclic rearrangements: synthesis of 4(5)-acylamino-imidazoles.

PubMed

Piccionello, Antonio Palumbo; Buscemi, Silvestre; Vivona, Nicolò; Pace, Andrea

2010-08-06

A new variation on the Boulton-Katritzky reaction is reported, namely, involving use of a CNC side chain. A novel Montmorillonite-K10 catalyzed nonreductive transamination of a 3-benzoyl-1,2,4-oxadiazole afforded a 3-(alpha-aminobenzyl)-1,2,4-oxadiazole, which was condensed with benzaldehydes to afford the corresponding imines. In the presence of strong base, these imines underwent Boulton-Katritzky-type rearrangement to afford novel 4(5)-acylaminoimidazoles.

One-pot, two-step desymmetrization of symmetrical benzils catalyzed by the methylsulfinyl (dimsyl) anion.

PubMed

Ragno, Daniele; Bortolini, Olga; Giovannini, Pier Paolo; Massi, Alessandro; Pacifico, Salvatore; Zaghi, Anna

2014-08-14

An operationally simple one-pot, two-step procedure for the desymmetrization of benzils is herein described. This consists in the chemoselective cross-benzoin reaction of symmetrical benzils with aromatic aldehydes catalyzed by the methyl sulfinyl (dimsyl) anion, followed by microwave-assisted oxidation of the resulting benzoylated benzoins with nitrate, avoiding the costly isolation procedure. Both electron-withdrawing and electron-donating substituents may be accommodated on the aromatic rings of the final unsymmetrical benzil.

Possible initial steps in the catabolism of 1,2-diphenylethanone (deoxybenzoin) by Pseudomonas fluorescens DB-5.

PubMed Central

Hinrichsen, P; Vicuña, R

1993-01-01

A natural bacterial strain, identified as Pseudomonas fluorescens DB-5, was isolated in enrichment cultures containing 1,2-diphenylethanone as the only source of carbon and energy. On the basis of characteristic features observed in the mass spectra of degradation intermediates, it is proposed that metabolism of 1,2-diphenylethanone is initiated by two hydroxylations on the benzyl ring. Phenol, presumably arising from the benzoyl ring, was transiently detected as a catabolic intermediate. PMID:8250568

Activity of capryloyl collagenic acid against bacteria involved in acne.

PubMed

Fourniat, J; Bourlioux, P

1989-12-01

Synopsis Capryloyl collagenic acid (Lipacide C8Co) has similar bacteriostatic activity in vitro to that of benzoyl peroxide towards the bacteria found in acne lesions (Staphylococcus aureus, Staphylococcus epidermidis and Propionibacterium acnes) (MIC between 1 and 4 mg ml(-1) for C8Co, and between 0.5 and 5 mg ml(-1) for benzoyl peroxide). The presence of Emulgine M8 did not affect the bacteriostatic activity of C8Co. A 4% w/v solution of C8Co (incorporating Emulgine M8) fulfilled the criteria for an antiseptic preparation as laid down by the French Pharmacopoeia (10th Edition), and had a spectrum 5 bactericidal activity according to the French Standard AFNOR NF T 72-151. The excellent cutaneous tolerance of capryloyl collagenic acid would indicate that an aqueous solution might be of value for topical treatment of the bacterial component of acne. Résumé Activité antibactérienne de l'acide capryloyl-collagénique vis à vis des bactéries impliquées dans l'etiologie de l'acné L'acide capryloyl-collagénique (Lipacide C8Co) et le peroxyde de benzoyle présentent une activité bactériostatique in-vitroéquivalente vis à vis des espèces bactériennes retrouvées au niveau des lésions acnéiques (Staphylococcus aureus, S. epidermidis et Propionibacterium acnes) (CMI comprise entre 1 et 4 mg ml(-1) pour le lipoaminoacide, et 0,5 et 5 mg ml(-1) pour le peroxyde de benzoyle). La mise en solution aqueuse de l'acide capryloyl-collagénique en présence d'Emulgine M8 ne modifie pas son activité bactériostatique. Une telle solution, à 4% m/V d'acide capryloyl-collagénique et 5% m/V d'Emulgine M8, satisfait à l'essai d'activité des préparations antiseptiques décrit à la Pharmacopée Française (Xème Ed.) (concentration minimale antiseptique: 10% v/V, pour un temps de contact de 5 min à 32 degrees C entre les germes tests et la solution diluée en eau distillée), et posséde une activité bactéricide antiseptique spectre 5 conforme à la norme AFNOR NF T

The impact of iron on the bleaching efficacy of hydrogen peroxide in liquid whey systems.

PubMed

Jervis, Suzanne M; Drake, MaryAnne

2013-02-01

Whey is a value-added product that is utilized in many food and beverage applications for its nutritional and functional properties. Whey and whey products are generally utilized in dried ingredient applications. One of the primary sources of whey is from colored Cheddar cheese manufacture that contains the pigment annatto resulting in a characteristic yellow colored Cheddar cheese. The colorant is also present in the liquid cheese whey and must be bleached so that it can be used in ingredient applications without imparting a color. Hydrogen peroxide and benzoyl peroxide are 2 commercially approved chemical bleaching agents for liquid whey. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been previously reported for whey bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how bleaching can impact flavor and functionality of dried ingredients. Currently, the precise mechanisms of off-flavor development and functionality changes are not entirely understood. Iron reactions in a bleached liquid whey system may play a key role. Reactions between iron and hydrogen peroxide have been widely studied since the reaction between these 2 relatively stable species can cause great destruction in biological and chemical systems. The actual mechanism of the reaction of iron with hydrogen peroxide has been a controversy in the chemistry and biological community. The precise mechanism for a given reaction can vary greatly based upon the concentration of reactants, temperature, pH, and addition of biological material. In this review, some hypotheses for the mechanisms of iron reactions that may occur in fluid whey that may impact bleaching efficacy, off-flavor development, and changes in functionality are presented. Cheese whey is bleached to remove residual carotenoid cheese colorant. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have

Synthesis of 3-aminopropyl β-(1 → 6)-d-glucotetraoside and its biotinylated derivative.

PubMed

Yashunsky, Dmitry V; Karelin, Alexander A; Tsvetkov, Yury E; Nifantiev, Nikolay E

2018-01-02

3-Aminopropyl β-(1 → 6)-d-glucotetraoside has been synthesized from 3-benzyloxycarbonylaminopropanol and 6-O-acetyl-2,3,4-tri-O-benzoyl-d-glucopyranosyl trichloroacetimidate by successive attachment of one monosaccharide unit in total yield of 22%. Free aminopropyl glycoside was converted into a biotin derivative that can be used for controlled immobilization of the oligosaccharide on streptavidin-coated ELISA plates and for tracing carbohydrate binding molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.

Terpenoids from Tripterygium doianum (Celastraceae).

PubMed

Tanaka, Naonobu; Duan, Hongquan; Takaishi, Yoshihisa; Kawazoe, Kazuyoshi; Goto, Satoru

2002-09-01

The extract of Tripterygium doianum (Celastraceae) afforded three triterpenoids [3beta-acetoxy-11-ursen-13alpha,30-olide, 25-chloro-24-hydroxytirucall-7-en-3-one and tirucall-7-en-3,24-dione], two sesquiterpenoids [5alpha-acetoxy-1beta,8alpha-bis-cinnamoyl-4alpha-hydroxydihydroagarofuran and 5alpha-acetoxy-1beta-benzoyl-8alpha-cinnamoyl-4alpha-hydroxydihydroagarofuran] and nine known triterpenoids. Their structures were established based on spectroscopic studies. Copyright 2002 Elsevier Science Ltd.

The Synthesis of Potentially Catalytic Bimetallic Systems.

DTIC Science & Technology

1982-11-29

a synthetic sequence to the double metal system shown in Figure XIV (p. 19) which incorporates ferrocene as the backbone of the molecule. Such systems...diketone intermediate 1-benzoyl-1’-o-chlorobenzoyl- ferrocene (over) \\/ DO I ?,S 1473 EDITION orI Nov6II s OSETe UNCLASSIFIEDj S/N 0102. LF 014- 6601...to the double metal system shown in Figure XIV (p. 19) which incorporates ferrocene as the backbone of the molecule. Such systems have the potential

An unusual strategy for the anoxic biodegradation of phthalate.

PubMed

Ebenau-Jehle, Christa; Mergelsberg, Mario; Fischer, Stefanie; Brüls, Thomas; Jehmlich, Nico; von Bergen, Martin; Boll, Matthias

2017-01-01

In the past two decades, the study of oxygen-independent degradation of widely abundant aromatic compounds in anaerobic bacteria has revealed numerous unprecedented enzymatic principles. Surprisingly, the organisms, metabolites and enzymes involved in the degradation of o-phthalate (1,2-dicarboxybenzene), mainly derived from phthalate esters that are annually produced at the million ton scale, are sparsely known. Here, we demonstrate a previously unknown capacity of complete phthalate degradation in established aromatic compound-degrading, denitrifying model organisms of the genera Thauera, Azoarcus and 'Aromatoleum'. Differential proteome analyses revealed phthalate-induced gene clusters involved in uptake and conversion of phthalate to the central intermediate benzoyl-CoA. Enzyme assays provided in vitro evidence for the formation of phthaloyl-CoA by a succinyl-CoA- and phthalate-specific CoA transferase, which is essential for the subsequent oxygen-sensitive decarboxylation to benzoyl-CoA. The extreme instability of the phthaloyl-CoA intermediate requires highly balanced CoA transferase and decarboxylase activities to avoid its cellular accumulation. Phylogenetic analysis revealed phthaloyl-CoA decarboxylase as a novel member of the UbiD-like, (de)carboxylase enzyme family. Homologs of the encoding gene form a phylogenetic cluster and are found in soil, freshwater and marine bacteria; an ongoing global distribution of a possibly only recently evolved degradation pathway is suggested.

Combined effects of microwaves, electron beams and polyfunctional monomers on rubber vulcanization.

PubMed

Manaila, Elena; Martin, Diana; Stelescu, Daniela Zuga; Craciun, Gabriela; Ighigeanu, Daniel; Matei, Constantin

2009-01-01

This paper presents comparative results obtained by conventional vulcanization with benzoyl peroxide (CV-BP), separate electron beam vulcanization (EB-V) and simultaneous electron beam and microwave vulcanization (EB+MW-V) applied to two kind of rubber samples: EVA (ethylene vinyl acetate) rubber-sample (EVA-sample) and EPDM (ethylene-propylene terpolymer) rubber-sample (EPDM-sample). The EVA-samples contain 61.54% EVA Elvax 260, 30.77% carbon black, 1.85% TAC (triallylcyanurate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyethylene glycol and antioxidant). The EPDM-samples contain 61.54% EPDM Nordel 4760, 30.77% carbon black, 1.85% TMPT (trimethylopropane trimethacrylate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyethylene glycol and antioxidant). The rubber samples designed for different vulcanization methods were obtained from raw rubber mixtures, as compressed sheets of 2 mm in the polyethylene foils to minimize oxidation. For EB and EB + MW treatments the sheets were cut in rectangular shape 0.15 x 0.15 m2. The physical properties of samples obtained by CV-BP EV-Vand EB + MW-V methods were evaluated by measuring the tearing strength, residual elongation, elongation at break, tensile strength, 300% modulus, 100% modulus, elasticity and hardness. The obtained results demonstrate an improvement of rubber several properties obtained by EB and EB + MW processing as compared to classical procedure using benzoyl peroxide.

Epoxyethylglycyl peptides as inhibitors of oligosaccharyltransferase: double-labelling of the active site.

PubMed

Bause, E; Wesemann, M; Bartoschek, A; Breuer, W

1997-02-15

Pig liver oligosaccharyltransferase (OST) is inactivated irreversibly by a hexapeptide in which threonine has been substituted by epoxyethylglycine in the Asn-Xaa-Thr glycosylation triplet. Incubation of the enzyme in the presence of Dol-PP-linked [14C]oligosaccharides and the N-3,5-dinitrobenzoylated epoxy derivative leads to the double-labelling of two subunits (48 and 66 kDa) of the oligomeric OST complex, both of which are involved in the catalytic activity. Labelling of both subunits was blocked competitively by the acceptor peptide N-benzoyl-Asu-Gly-Thr-NHCH3 and by the OST inhibitor N-benzoyl-alpha,gamma-diaminobutyric acid-Gly-Thr-NHCH3, but not by an analogue derived from the epoxy-inhibitor by replacing asparagine with glutamine. Our data clearly show that double-labelling is an active-site-directed modification, involving inhibitor glycosylation at asparagine and covalent attachment of the glycosylated inhibitor, via the epoxy group, to the enzyme. Double-labelling of OST can occur as the result of either a consecutive or a syn-catalytic reaction sequence. The latter mechanism, during the course of which OST catalyses its own 'suicide' inactivation, is more likely, as suggested by indirect experimental evidence. The syn-catalytic mechanism corresponds with our current view of the functional role of the acceptor site Thr/Ser acting as a hydrogen-bond acceptor, not a donor, during transglycosylation.

Physiological and Proteomic Adaptation of “Aromatoleum aromaticum” EbN1 to Low Growth Rates in Benzoate-Limited, Anoxic Chemostats

PubMed Central

Trautwein, Kathleen; Lahme, Sven; Wöhlbrand, Lars; Feenders, Christoph; Mangelsdorf, Kai; Harder, Jens; Steinbüchel, Alexander; Blasius, Bernd; Reinhardt, Richard

2012-01-01

“Aromatoleum aromaticum” EbN1 was cultivated at different growth rates in benzoate-limited chemostats under nitrate-reducing conditions. Physiological characteristics, proteome dynamics, phospholipid-linked fatty acid (PLFA) composition, and poly(3-hydroxybutyrate) (PHB) content were analyzed in steady-state cells at low (μlow) (0.036 h−1), medium (μmed) (0.108 h−1), and high (μhigh) (0.180 h−1) growth rates. A positive correlation to growth rate was observed for cellular parameters (cell size, and DNA and protein contents). The free energy consumed for biomass formation steadily increased with growth rate. In contrast, the energy demand for maintenance increased only from μlow to μmed and then remained constant until μhigh. The most comprehensive proteomic changes were observed at μlow compared to μhigh. Uniformly decreased abundances of protein components of the anaerobic benzoyl coenzyme A (benzoyl-CoA) pathway, central carbon metabolism, and information processing agree with a general deceleration of benzoate metabolism and cellular processes in response to slow growth. In contrast, increased abundances were observed at μlow for diverse catabolic proteins and components of uptake systems in the absence of the respective substrate (aromatic or aliphatic compounds) and for proteins involved in stress responses. This potential catabolic versatility and stress defense during slow growth may be interpreted as preparation for future needs. PMID:22366417

Synthesis and In Vitro Evaluation of 5-[18F]Fluoroalkyl Pyrimidine Nucleosides for Molecular Imaging of Herpes Simplex Virus Type-1 Thymidine Kinase Reporter Gene Expression

PubMed Central

Chacko, Ann-Marie; Qu, Wenchao; Kung, Hank F.

2014-01-01

Two novel series of 5-fluoroalkyl-2′-deoxyuridines (FPrDU, FBuDU, FPeDU) and 2′-fluoro-2′-deoxy-5-fluoroalkylarabinouridines (FFPrAU, FFBuAU, FFPeAU), having three, four or five methylene units (propyl, butyl, or pentyl) at C-5, were prepared and tested as reporter probes for imaging HSV1-tk gene expression. The Negishi coupling methodology was employed to efficiently synthesize the radiolabeling precursors. All six 5-[18F]fluoroalkyl pyrimidines were prepared readily from 3-N-benzoyl-3′,5′-di-O-benzoyl-protected 5-O-mesylate precursors in 17–35% radiochemical yield (decay-corrected). In vitro studies highlighted that all six [18F]labeled nucleosides selectively accumulated in cells expressing the HSV1-TK protein, with negligible uptake in control cells. [18F]FPrDU, [18F]FBuDU, [18F]FPeDU, and [18F]FFBuAU had the best uptake profiles. Despite selective accumulation in HSV1-tk expressing cells, all 5-fluoroalkyl pyrimidine nucleosides had low to negligible cytotoxic activity (CC50>1000–209 μM). Ultimately, results demonstrated that 5-[18F]fluoropropyl, [18F]fluorobutyl, and [18F]fluoropentyl pyrimidine nucleosides have potential as in vivo HSV1-TK PET reporter probes over a dynamic range of reporter gene expression levels. PMID:18800764

Synthesis, Molecular Docking, and Antimycotic Evaluation of Some 3-Acyl Imidazo[1,2-a]pyrimidines.

PubMed

Gómez-García, Omar; Andrade-Pavón, Dulce; Campos-Aldrete, Elena; Ballinas-Indilí, Ricardo; Méndez-Tenorio, Alfonso; Villa-Tanaca, Lourdes; Álvarez-Toledano, Cecilio

2018-03-07

A series of 3-benzoyl imidazo[1,2- a ]pyrimidines, obtained from N -heteroarylformamidines in good yields, was tested in silico and in vitro for binding and inhibition of seven Candida species ( Candida albicans (ATCC 10231), Candida dubliniensis (CD36), Candida glabrata (CBS138), Candida guilliermondii (ATCC 6260), Candida kefyr , Candida krusei (ATCC 6358) and Candida tropicalis (MYA-3404)). To predict binding mode and energy, each compound was docked in the active site of the lanosterol 14α-demethylase enzyme (CYP51), essential for fungal growth of Candida species. Antimycotic activity was evaluated as the 50% minimum inhibitory concentration (MIC50) for the test compounds and two reference drugs, ketoconazole and fluconazole. All test compounds had a better binding energy (range: -6.11 to -9.43 kcal/mol) than that found for the reference drugs (range: 48.93 to -6.16 kcal/mol). In general, the test compounds showed greater inhibitory activity of yeast growth than the reference drugs. Compounds 4j and 4f were the most active, indicating an important role in biological activity for the benzene ring with electron-withdrawing substituents. These compounds show the best MIC50 against C. guilliermondii and C. glabrata, respectively. The current findings suggest that the 3-benzoyl imidazo[1,2- a ]pyrimidine derivatives, herein synthesized by an accessible methodology, are potential antifungal drugs.

An unusual strategy for the anoxic biodegradation of phthalate

PubMed Central

Ebenau-Jehle, Christa; Mergelsberg, Mario; Fischer, Stefanie; Brüls, Thomas; Jehmlich, Nico; von Bergen, Martin; Boll, Matthias

2017-01-01

In the past two decades, the study of oxygen-independent degradation of widely abundant aromatic compounds in anaerobic bacteria has revealed numerous unprecedented enzymatic principles. Surprisingly, the organisms, metabolites and enzymes involved in the degradation of o-phthalate (1,2-dicarboxybenzene), mainly derived from phthalate esters that are annually produced at the million ton scale, are sparsely known. Here, we demonstrate a previously unknown capacity of complete phthalate degradation in established aromatic compound-degrading, denitrifying model organisms of the genera Thauera, Azoarcus and ‘Aromatoleum'. Differential proteome analyses revealed phthalate-induced gene clusters involved in uptake and conversion of phthalate to the central intermediate benzoyl-CoA. Enzyme assays provided in vitro evidence for the formation of phthaloyl-CoA by a succinyl-CoA- and phthalate-specific CoA transferase, which is essential for the subsequent oxygen-sensitive decarboxylation to benzoyl-CoA. The extreme instability of the phthaloyl-CoA intermediate requires highly balanced CoA transferase and decarboxylase activities to avoid its cellular accumulation. Phylogenetic analysis revealed phthaloyl-CoA decarboxylase as a novel member of the UbiD-like, (de)carboxylase enzyme family. Homologs of the encoding gene form a phylogenetic cluster and are found in soil, freshwater and marine bacteria; an ongoing global distribution of a possibly only recently evolved degradation pathway is suggested. PMID:27392087

A cluster of bacterial genes for anaerobic benzene ring biodegradation

PubMed Central

Egland, Paul G.; Pelletier, Dale A.; Dispensa, Marilyn; Gibson, Jane; Harwood, Caroline S.

1997-01-01

A reductive benzoate pathway is the central conduit for the anaerobic biodegradation of aromatic pollutants and lignin monomers. Benzene ring reduction requires a large input of energy and this metabolic capability has, so far, been reported only in bacteria. To determine the molecular basis for this environmentally important process, we cloned and analyzed genes required for the anaerobic degradation of benzoate and related compounds from the phototrophic bacterium, Rhodopseudomonas palustris. A cluster of 24 genes was identified that includes twelve genes likely to be involved in anaerobic benzoate degradation and additional genes that convert the related compounds 4-hydroxybenzoate and cyclohexanecarboxylate to benzoyl-CoA. Genes encoding benzoyl-CoA reductase, a novel enzyme able to overcome the resonance stability of the aromatic ring, were identified by directed mutagenesis. The gene encoding the ring-cleavage enzyme, 2-ketocyclohexanecarboxyl-CoA hydrolase, was identified by assaying the enzymatic activity of the protein expressed in Escherichia coli. Physiological data and DNA sequence analyses indicate that the benzoate pathway consists of unusual enzymes for ring reduction and cleavage interposed among enzymes homologous to those catalyzing fatty acid degradation. The cloned genes should be useful as probes to identify benzoate degradation genes from other metabolically distinct groups of anaerobic bacteria, such as denitrifying bacteria and sulfate-reducing bacteria. PMID:9177244

A new synthesis of certain 7-(beta-D-ribofuranosyl) and 7-(2-deoxy-beta-D-ribofuranosyl) derivatives of 3-deazaguanine via the sodium salt glycosylation procedure.

PubMed Central

Gupta, P K; Robins, R K; Revankar, G R

1985-01-01

A facile synthesis of 7-beta-D-ribofuranosyl-3-deazaguanine (1) and certain 8-substituted derivatives of 1 via the sodium salt glycosylation method has been developed. Glycosylation of the sodium salt of methyl 2-chloro(or methylthio)-4(5)-cyanomethylimidazole-5(4)-carboxylate (5 and 13b) with 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide (6) gave exclusively methyl 2-chloro(or methylthio)-4-cyanomethyl-1-(2,3, 5-tri-O-benzoyl-beta-D-ribofuranosyl)imidazole-5-carboxylate (7 and 14a), respectively. Ammonolysis of 7 and 14a provided 6-amino-2-chloro(or methylthio)-3-beta-D-ribofuranosylimidazo-[4,5-c]pyridin-4(5H)-one (11 and 17), which on subsequent dehalogenation (or dethiation) gave 1. Similarly, reaction of the sodium salt of 5 and 13b with 1-chloro-2-deoxy-3,5-di-O-p-toluoyl-alpha-D-erythro-pentofuranose (8), and ammonolysis of the glycosylated imidazole precursors (9 and 16) gave 6-amino-2-chloro(or methylthio)-3-(2-deoxy-beta-D-erythro-pentofuranosyl) imidazo[4,5-c]-pyridin-4(5H)-one (10a and 15), respectively. Dehalogenation of 10a or dethiation of 15 gave 2'-deoxy-7-beta-D-ribofuranosyl-3-deazaguanine (10b). This procedure provided a direct method of obtaining 10b without the contaminating 9-glycosyl isomer 4. PMID:4022783

Heteropoly acid encapsulated into zeolite imidazolate framework (ZIF-67) cage as an efficient heterogeneous catalyst for Friedel–Crafts acylation

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

Ammar, Muhammad; Jiang, Sai; Ji, Shengfu, E-mail: jisf@mail.buct.edu.cn

2016-01-15

A new strategy has been developed for the encapsulation of the phosphotungstic heteropoly acid (H{sub 3}PW{sub 12}O{sub 40} denoted as PTA) into zeolite imidazolate framework (ZIF-67) cage and the PTA@ZIF-67(ec) catalysts with different PTA content were prepared. The structure of the catalysts was characterized by XRD, BET, SEM, FT-IR, ICP-AES and TG. The catalytic activity and recovery properties of the catalysts for the Friedel-Crafts acylation of anisole with benzoyl chloride were evaluated. The results showed that 14.6–31.7 wt% PTA were encapsulated in the ZIF-67 cage. The PTA@ZIF-67(ec) catalysts had good catalytic activity for Friedel-Crafts acylation. The conversion of anisole canmore » reach ~100% and the selectivity of the production can reach ~94% over 26.5 wt% PTA@ZIF-67(ec) catalyst under the reaction condition of 120 °C and 6 h. After reaction, the catalyst can be easily separated from the reaction mixture by the centrifugation. The recovered catalyst can be reused five times and the selectivity can be kept over 90%. - Graphical abstract: The PTA@ZIF-67 catalysts with different PTA content were prepared by encapsulating the PTA into ZIF-67 cage and the as-synthesized catalysts exhibited good catalytic activity for the Friedel–Craft acylation of anisole with benzoyl chloride.« less

4-Bromo-N-(di-n-propyl-carbamothioyl)-benzamide.

PubMed

Binzet, Gün; Flörke, Ulrich; Külcü, Nevzat; Arslan, Hakan

2009-02-04

The synthesis of the title compound, C(14)H(19)BrN(2)OS, involves the reaction of 4-bromo-benzoyl chloride with potassium thio-cyanate in acetone followed by condensation of the resulting 4-bromo-benzoyl isothio-cyanate with di-n-propyl-amine. Typical thio-urea carbonyl and thio-carbonyl double bonds, as well as shortened C-N bonds, are observed in the title compound. The short C-N bond lengths in the centre of the mol-ecule reveal the effects of resonance in this part of the mol-ecule. The asymmetric unit of the title compound contains two crystallographically independent mol-ecules, A and B. There is very little difference between the bond lengths and angles of these mol-ecules. In mol-ecule B, one di-n-propyl group is twisted in a -anti-periplanar conformation with C-C-C-H = -179.1 (3)° and the other adopts a -synclinal conformation with C-C-C-H = -56.7 (4)°; in mol-ecule A the two di-n-propyl groups are twisted in + and -anti-periplanar conformations, with C-C-C-H = -179.9 (3) and 178.2 (3)°, respectively. In the crystal, the mol-ecules are linked into dimeric pairs via pairs of N-H⋯S hydrogen bonds.

Novel benzothiophene 1,1-dioxide deoxygenation path for the microwave-assisted synthesis of substituted benzothiophene-fused pyrrole derivatives.

PubMed

Karakuş, Hamza; Dürüst, Yaşar

2017-02-01

The reaction of C-(4-substituted-phenyl)-N-(benzoyl)-N-methylglycines with benzo[b]thiophene 1,1-dioxide unexpectedly gave benzothiophene-fused pyrrole derivatives in toluene under microwave irradiation via a cycloaddition and metal-free Pummerer-type sulfone deoxygenation path. In order to obtain the desired sulfone derivatives, the sulfide group underwent oxidation with m-CPBA to afford sulfones. The structures of all the new products were elucidated by spectroscopic/physical methods and, in two cases, by X-ray diffraction.

4-O-beta-D-galactopyranosyl-D-xylose: a new synthesis and application to the evaluation of intestinal lactase.

PubMed

Rivera-Sagredo, A; Fernández-Mayoralas, A; Jiménez-Barbero, J; Martín-Lomas, M; Villanueva, D; Aragón, J J

1992-04-10

4-O-beta-D-Galactopyranosyl-D-xylose (2) was prepared from benzyl 2,3-O-isopropylidene-beta-D-xylopyranoside by glycosylation with 2,3,4,6-tetra-O-benzoyl-alpha-D-galactopyranosyl bromide and subsequent deprotection. Compound 2 was hydrolyzed in vitro by intestinal lactase; the Vmax was 25% of that with lactose and the Km was 370mM (cf. 27mM for lactose). Oral administration of 2 suckling rats led to urinary excretion of D-xylose which could be estimated colorimetrically.

Arabinofuranose 1,2,5-orthobenzoate as a single precursor of linear α(1 → 5)-linked oligoarabinofuranosides.

PubMed

Panova, Maria V; Podvalnyy, Nikita M; Okun, Eugene L; Abronina, Polina I; Chizhov, Alexander O; Kononov, Leonid O

2018-02-01

Selectively protected mono-, di- and trisaccharide thioglycoside building blocks with unprotected primary hydroxy group at the non-reducing end, available in only one step from 3-O-benzoyl β-d-arabinofuranose 1,2,5-orthobenzoate, were used in the synthesis of linear α(1 → 5)-linked oligoarabinofuranosides up to octasaccharide. The obtained oligosaccharides contain 4-(2-chloroethoxy)phenyl (CEP) or 4-(2-azidoethoxy)phenyl (AEP) pre-spacer aglycons that allow preparation of neoglycoconjugates. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Synthesis and Study of Azole Carboxamide Nucleosides as Agents Active Against RNA Viruses.

DTIC Science & Technology

1986-09-15

solvent such as nitromethane gave a nucleoside product , identified as 1-(2,3,5-tri-O-benzoyl-o--D-ribofuranosyl)-l,2,4- triazol-3(2H)-one (20, BL-00307...at 2220 cm . Treatment of 26 with NH4OH/H 202 solution, and purification of the reaction product by chromatography on silica gel furnished 1-(2-deoxy...30) in 74% yield. Treatment of 30 with NH4OH/H202 solution, and purification of the reaction product by chroma- tography on silica gel furnished 1

Coexistence of spin crossover and magnetic ordering in a dendrimeric Fe(III) complex

NASA Astrophysics Data System (ADS)

Vorobeva, V. E.; Domracheva, N. E.; Pyataev, A. V.; Gruzdev, M. S.; Chervonova, U. V.

2015-01-01

The magnetic properties of a new dendrimeric spin crossover Fe(III) complex, [Fe(L)2]+PF6-, where L = 3,5-di[3,4,5-tris(tetradecyloxy) benzoyloxy]benzoyl-4-salicylidene-N-ethyl-N-ethylene-diamine, are reported for the first time. EPR studies show that this compound undergoes a gradual spin transition in the temperature range 70-300 K and has antiferromagnetic ordering below 10 K. Mössbauer spectroscopy at 5 K confirms the presence of magnetic ordering in the dendrimeric iron complex.

The Molecular Determinants of Small-Molecule Ligand Binding at P2X Receptors

PubMed Central

Pasqualetto, Gaia; Brancale, Andrea; Young, Mark T.

2018-01-01

P2X receptors are trimeric eukaryotic ATP-gated cation channels. Extracellular ATP—their physiological ligand—is released as a neurotransmitter and in conditions of cell damage such as inflammation, and substantial evidence implicates P2X receptors in diseases including neuropathic pain, cancer, and arthritis. In 2009, the first P2X crystal structure, Danio rerio P2X4 in the apo- state, was published, and this was followed in 2012 by the ATP-bound structure. These structures transformed our understanding of the conformational changes induced by ATP binding and the mechanism of ligand specificity, and enabled homology modeling of mammalian P2X receptors for ligand docking and rational design of receptor modulators. P2X receptors are attractive drug targets, and a wide array of potent, subtype-selective modulators (mostly antagonists) have been developed. In 2016, crystal structures of human P2X3 in complex with the competitive antagonists TNP-ATP and A-317491, and Ailuropoda melanoleuca P2X7 in complex with a series of allosteric antagonists were published, giving fascinating insights into the mechanism of channel antagonism. In this article we not only summarize current understanding of small-molecule modulator binding at P2X receptors, but also use this information in combination with previously published structure-function data and molecular docking experiments, to hypothesize a role for the dorsal fin loop region in differential ATP potency, and describe novel, testable binding conformations for both the semi-selective synthetic P2X7 agonist 2′-(3′)-O-(4-benzoyl)benzoyl ATP (BzATP), and the P2X4-selective positive allosteric modulator ivermectin. We find that the distal benzoyl group of BzATP lies in close proximity to Lys-127, a residue previously implicated in BzATP binding to P2X7, potentially explaining the increased potency of BzATP at rat P2X7 receptors. We also present molecular docking of ivermectin to rat P2X4 receptors, illustrating a plausible

Synthesis, electronic and ESR spectral studies on copper(II) nitrate complexes with some acylhydrazines and hydrazones.

PubMed

Singh, Vinod P

2008-11-01

This paper describes the preparation of [Cu(bh)2(H2O)2](NO3)2], [Cu(ibh)2(NO3)2], [Cu(ibh)2(H2O)2](NO3)2 and [Cu(iinh)2(NO3)2] (bh = benzoyl hydrazine (C6H5CONHNH2); ibh = isonicotinoyl hydrazine (NC5H4CONHNH2); ibh = isopropanone benzoyl hydrazone (C6H5CONHN=C(CH3)2; iinh = isopropanone isonicotinoyl hydrazone (NC5H4CONHN=C(CH3)2). These copper(II) complexes are characterized by elemental analyses, molar conductances, dehydration studies, ESR, IR and electronic spectral studies. The electronic and ESR spectra indicate that each complex exhibits a six-coordinate tetragonally distorted octahedral geometry in the solid state and in DMSO solution. The ESR spectra of most of the complexes are typically isotropic type at room temperature (300 K) in solid state as well as in DMSO solution. However, all the complexes exhibit invariably axial signals at 77 K in DMSO solution. The trend g(||) > g(perpendicular) > g(e,) observed in all the complexes suggests the presence of an unpaired electron in the d x2-y2 orbital of the Cu(II). The bh and inh ligands bond to Cu(II) through the >C=O and -NH2 groups whereas, ibh and iinh bond through >C=O and >C=N- groups. The IR spectra of bh and ibh complexes also show H-O-H stretching and bending modes of coordinated water.

Patch-test reactions to plastic and glue allergens.

PubMed

Kanerva, L; Jolanki, R; Alanko, K; Estlander, T

1999-07-01

Plastics and glues are common causes of occupational dermatoses, but only few reports have dealt with patch-test reactions caused by plastic and glue allergens. Patients exposed to plastics and remitted to an occupational dermatology clinic, were patch-tested with 50-53 plastic and glue allergens during a 6-year period. Conventional patch-test techniques were used. The most common causes of allergic patch-test reactions in 360 patients were novolac epoxy resin (5.1%), phenol formaldehyde resin (3.1%), 4-tert-butylcatechol (2.6%), phenyl glycidyl ether (2.6%), diaminodiphenyl methane (2.2%), benzoyl peroxide (2.2%), hexamethylene tetramine (2.0%) and o-cresyl glycidyl ether (1.6%). The allergens that most often elicited irritant patch-test reactions were: benzoyl peroxide (9.5%), abitol alcohol (3.6%), hydroquinone (3.1%), acid-catalyzed phenol formaldehyde resin (2.5%) and toluene diisocyanate (1.9%). Twenty-six out of 53 chemicals caused no allergic reaction during the 6-year period. Plastic allergens in the standard series provoked allergic reactions with formaldehyde (5.8%), diglycidyl ether of bisphenol A (3.2%), 4-tert-butylphenol-formaldehyde-resin (1.1%), toluene sulphonamide formaldehyde-resin (1.1%) and triethylenglycol diacrylate (0.4%). Although half of the plastic chemicals gave no allergic patch-test reactions during a 6-year period, with unusual allergens this low yield needs to be accepted, because otherwise rare allergies will not be detected. Also a negative reaction has diagnostic value.

Policing starter unit selection of the enterocin type II polyketide synthase by the type II thioesterase EncL.

PubMed

Kalaitzis, John A; Cheng, Qian; Meluzzi, Dario; Xiang, Longkuan; Izumikawa, Miho; Dorrestein, Pieter C; Moore, Bradley S

2011-11-15

Enterocin is an atypical type II polyketide synthase (PKS) product from the marine actinomycete 'Streptomyces maritimus'. The enterocin biosynthesis gene cluster (enc) codes for proteins involved in the assembly and attachment of the rare benzoate primer that initiates polyketide assembly with the addition of seven malonate molecules and culminates in a Favorskii-like rearrangement of the linear poly-β-ketone to give its distinctive non-aromatic, caged core structure. Fundamental to enterocin biosynthesis, which utilizes a single acyl carrier protein (ACP), EncC, for both priming with benzoate and elongating with malonate, involves maintaining the correct balance of acyl-EncC substrates for efficient polyketide assembly. Here, we report the characterization of EncL as a type II thioesterase that functions to edit starter unit (mis)priming of EncC. We performed a series of in vivo mutational studies, heterologous expression experiments, in vitro reconstitution studies, and Fourier-transform mass spectrometry-monitored competitive enzyme assays that together support the proposed selective hydrolase activity of EncL toward misprimed acetyl-ACP over benzoyl-ACP to facilitate benzoyl priming of the enterocin PKS complex. While this system resembles the R1128 PKS that also utilizes an editing thioesterase (ZhuC) to purge acetate molecules from its initiation module ACP in favor of alkylacyl groups, the enterocin system is distinct in its usage of a single ACP for both priming and elongating reactions with different substrates. Copyright © 2011 Elsevier Ltd. All rights reserved.

Policing Starter Unit Selection of the Enterocin Type II Polyketide Synthase by the Type II Thioesterase EncL

PubMed Central

Kalaitzis, John A.; Cheng, Qian; Meluzzi, Dario; Xiang, Longkuan; Izumikawa, Miho; Dorrestein, Pieter C.; Moore, Bradley S.

2011-01-01

Enterocin is an atypical type II polyketide synthase (PKS) product from the marine actinomycete “Streptomyces maritimus”. The enterocin biosynthesis gene cluster (enc) codes for proteins involved in the assembly and attachment of the rare benzoate primer that initiates polyketide assembly with the addition of seven malonate molecules and culminates in a Favorskii-like rearrangement of the linear poly-β-ketone to give its distinctive non-aromatic, caged core structure. Fundamental to enterocin biosynthesis, which utilizes a single acyl carrier protein (ACP), EncC, for both priming with benzoate and elongating with malonate, involves maintaining the correct balance of acyl-EncC substrates for efficient polyketide assembly. Here we report the characterization of EncL as a type II thioesterase that functions to edit starter unit (mis)priming of EncC. We performed a series of in vivo mutational studies, heterologous expression experiments, in vitro reconstitution studies, and Fourier-transform mass spectrometry-monitored competitive enzyme assays that together support the proposed selective hydrolase activity of EncL toward misprimed acetyl-ACP over benzoyl-ACP to facilitate benzoyl priming of the enterocin PKS complex. While this system resembles the R1128 PKS that also utilizes an editing thioesterase (ZhuC) to purge acetate molecules from its initiation module ACP in favor of alkylacyl groups, the enterocin system is distinct in its usage of a single ACP for both priming and elongating reactions with different substrates. PMID:21531566

New luminescent bioprobes Eu(lll)-phloroglucinol derivatives and their spectrofluorimetric, electrochemical interactions with nucleotides and DNA.

PubMed

Azab, Hassan Ahmed; Anwar, Zeinab M; Abdel-Salam, Enas T; el-Sayed-Sebak, Mahmoud

2012-01-01

Two new ligands derived from phloroglucinol 2-{[(4-methoxy benzoyl)oxy]} methyl benzoic acid[L1] and 2-{[(4-methyl benzoyl)oxy] methyl} benzoic acid[L2] were synthesized. The solid complex Eu(III)-L2 has been synthesised and characterized by elemental analysis, UV and IR spectra. The reaction of Eu(III) with the two synthesized ligands has been investigated in I = 0.1 mol dm(-3) p-toluene sulfonate by cyclic voltammetry and square wave voltammetry. The reaction of Eu (III)-L1 and Eu (III)-L2 binary complexes with nucleotide 5'-AMP, 5'-ADP, 5'-ATP, 5'- GMP, 5'-IMP, and 5'-CMP has been investigated using UV, fluorescence and electrochemical methods. The experimental conditions were selected such that self-association of the nucleotides and their complexes was negligibly small, that is, the monomeric complexes were studied. The interaction of the Eu(III)-L1 or L2 solid complexes with calf-thymus DNA has been investigated by fluorescence and electrochemical methods including cyclic voltammetery(CV), differential pulse polarography (DPP) and square wave voltammetry (SWV) on a glassy carbon electrode. The fluorescence intensity of Eu(III)-L2 complex was enhanced with the addition of DNA. Under optimal conditions in phosphate buffer pH 7.0 at 25 °C the linear range is 3-20 μM for calf thymus DNA (CT-DNA) and the corresponding determination limit is 1.8 μM.

Mapping the Reactivity and Selectivity of 2-Azidofucosyl Donors for the Assembly of N-Acetylfucosamine-Containing Bacterial Oligosaccharides.

PubMed

Hagen, Bas; Ali, Sara; Overkleeft, Herman S; van der Marel, Gijsbert A; Codée, Jeroen D C

2017-01-20

The synthesis of complex oligosaccharides is often hindered by a lack of knowledge on the reactivity and selectivity of their constituent building blocks. We investigated the reactivity and selectivity of 2-azidofucosyl (FucN 3 ) donors, valuable synthons in the synthesis of 2-acetamido-2-deoxyfucose (FucNAc) containing oligosaccharides. Six FucN 3 donors, bearing benzyl, benzoyl, or tert-butyldimethylsilyl protecting groups at the C3-O and C4-O positions, were synthesized, and their reactivity was assessed in a series of glycosylations using acceptors of varying nucleophilicity and size. It was found that more reactive nucleophiles and electron-withdrawing benzoyl groups on the donor favor the formation of β-glycosides, while poorly reactive nucleophiles and electron-donating protecting groups on the donor favor α-glycosidic bond formation. Low-temperature NMR activation studies of Bn- and Bz-protected donors revealed the formation of covalent FucN 3 triflates and oxosulfonium triflates. From these results, a mechanistic explanation is offered in which more reactive acceptors preferentially react via an S N 2-like pathway, while less reactive acceptors react via an S N 1-like pathway. The knowledge obtained in this reactivity study was then applied in the construction of α-FucN 3 linkages relevant to bacterial saccharides. Finally, a modular synthesis of the Staphylococcus aureus type 5 capsular polysaccharide repeating unit, a trisaccharide consisting of two FucNAc units, is described.

Which acne treatment has the best influence on health-related quality of life? Literature review by the European Academy of Dermatology and Venereology Task Force on Quality of Life and Patient Oriented Outcomes.

PubMed

Chernyshov, P V; Tomas-Aragones, L; Manolache, L; Svensson, A; Marron, S E; Evers, A W M; Bettoli, V; Jemec, G B; Szepietowski, J C

2018-05-05

According to results of a recent literature search performed by the European Academy of Dermatology and Venereology (EADV) Task Forces (TF) on Quality of Life and Patient Oriented Outcomes (QoL and PO) and Acne, Rosacea and Hidradenitis Suppurativa (ARHS) most of publications where health-related (HR) QoL of acne patients was studied were clinical trials. Members of the EADV TF on QoL and PO decided to detect which acne treatment has the best influence on HRQoL of acne patients. A new literature search was organized to find publications on acne treatment where the HRQoL of patients was assessed as an outcome measure. From 186 papers with HRQoL assessment 37 papers were included for further analysis. Our results revealed that oral isotretinoin had the best influence on HRQoL of acne patients. Several other treatment methods also showed good effects on the HRQoL of acne patients. Oral isotretinoin and norethindrone acetate/ethinyl estradiol, topical clindamycin phosphate/benzoyl peroxide and adapalene/benzoyl peroxide showed significantly better effect on HRQoL than placebo. There is limited number of the high-quality studies on acne treatment where HRQoL were assessed. Dermatology-specific and acne-specific instruments showed much better sensitivity to successful therapeutic intervention than generic HRQoL instruments. The most frequently used HRQoL instrument was the DLQI questionnaire. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

[Studies on the chemical constituents from Cissus pteroclada].

PubMed

Chi, Cui-Yun; Wang, Feng; Lei, Ting; Xu, Shao-Yu; Hong, Ai-Hua; Cen, Ying-Zhou

2010-10-01

To study the chemical constituents of Yao Medicine Cissus pteroclada. The compounds were isolated and purified by column chromatography with silica gel, TLC and recrystallization. Their structures were elucidated on the basis of physicochemical properties and spectra analysis. Six compounds were isolated and identified as beta-sitosterol (I), bergenin (II), 11-O-galloylbergenin (III), 11-O-(4-hydroxy benzoyl) bergenin (IV), gallic acid (V), daucosterol (VI). Compounds III and NIV are obtained from the genus for the first time. All the compounds are isolated from this plant for the first time except the compound II.

Determination of pKa values of benzoxa-, benzothia- and benzoselena-zolinone derivatives by capillary electrophoresis. Comparison with potentiometric titration and spectrometric data.

PubMed

Foulon, C; Duhal, N; Lacroix-Callens, B; Vaccher, C; Bonte, J P; Goossens, J F

2007-07-01

Acidity constants of benzoxa-, benzothia- and benzoselena-zolinone derivatives were determined by capillary electrophoresis, potentiometry and spectrophotometry experiments. These three analytical techniques gave pK(a) results that were in good agreement. A convenient, accurate and precise method for the determination of pK(a) was developed to measure changes in acidity constants induced by heteroatom or 6-benzoyl substituted derivatives. pK(a) values were determined simultaneously for two compounds characterized by different electrophoretic mobility (micro(e)) and pK(a) value and in the presence of an analogous neutral marker.

Extractant composition

DOEpatents

Smith, Barbara F.; Jarvinen, Gordon D.; Ryan, Robert R.

1990-01-01

An organic extracting solution useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

Neglected aspects in the management of acne.

PubMed Central

Gordon, B

1985-01-01

Acne is the result of excessive grease on the skin. The successful treatment of acne depends essentially on the degreasing of the skin to an extent which produces peeling, which is the observable index of adequate treatment. The use of antibiotics is supplementary to degreasing and peeling. Degreasing is best achieved by thrice daily washing with Neutrogena acne cleansing soap, followed by the application of a benzoyl peroxide preparation of a suitable strength. If necessary, further degreasing can be achieved by cleansing with isopropyl alcohol after washing with the Neutrogena soap. PMID:2941579

A precursor to the beta-pyranosides of 3-amino-3,6-dideoxy-D-mannose (mycosamine).

PubMed

Alais, J; David, S

1992-06-04

SN2-type reaction of 3-O-(1-imidazyl)sulfonyl-1,2:5,6-di-O-isopropylidene-alpha-D-gluco furanose with benzoate gave the 3-O-benzoyl-alpha-D-allo derivative 2, which was hydrolysed to give the 5,6-diol 3. Compound 3 was converted into the 6-deoxy-6-iodo derivative 4 which was reduced with tributylstannane, and then position 5 was protected by benzyloxymethylation, to give 3-O-benzoyl-5-O-benzyloxymethyl-6-deoxy-1,2-O-isopropylidene-alpha -D- allofuranose (6). Debenzoylation of 6 gave 7, (1-imidazyl)sulfonylation gave 8, and azide displacement gave 3-azido-5-O-benzyloxymethyl-3,6-dideoxy- 1,2-O-isopropylidene-alpha-D-glucofuranose (9, 85%). Acetolysis of 9 gave 1,2,4-tri-O-acetyl-3-azido-3,6-dideoxy-alpha,beta-D-glucopyranose (10 and 11). Selective hydrolysis of AcO-1 in the mixture of 10 and 11 with hydrazine acetate (----12), followed by conversion into the pyranosyl chloride 13, treatment with N,N-dimethylformamide dimethyl acetal in the presence of tetrabutylammonium bromide, and benzylation gave 3-azido-4-O-benzyl-3,6-dideoxy-1,2-O-(1-methoxyethylidene)-alpha-D -glucopyranose (15). Treatment of 15 with dry acetic acid gave 1,2-di-O-acetyl-3-azido-4-O-benzyl-3,6-dideoxy-beta-D-glucopyranose (16, 86% yield) that was an excellent glycosyl donor in the presence of trimethylsilyl triflate, allowing the synthesis of cyclohexyl 2-O-acetyl-3-azido-4-O-benzyl-3,6-dideoxy-beta-D-glucopyranoside (17, 90%).(ABSTRACT TRUNCATED AT 250 WORDS)

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

Shardin, Rosidah; Pui, Law Kung; Yamin, Bohari M.

A simple mononuclear octahedral copper(II) complex was attempted from the reaction of three moles of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole and one mole of copper(II) perchlorate hexahydrate in methanol. However, the product of the reaction was confirmed to be a dinuclear copper(II) complex with μ-(3-(pyridin-2-yl)-pyrazolato) and 3-(pyridin-2-yl)-1H-pyrazole ligands attached to each of the Cu(II) centre atom. The copper(II) ion assisted the cleavage of the C{sub benzoyl}N bond afforded a 3-(pyridin-2-yl)-1H-pyrazole molecule. Deprotonation of the 3-(pyridin-2-yl)-1H-pyrazole gave a 3-(pyridin-2-yl)-pyrazolato, which subsequently reacted with the Cu(II) ion to give the (3-(pyridin-2-yl)-pyrazolato)(3-(pyridin-2-yl)-1H-pyrazole)Cu(II) product moiety. The structure of the dinuclear complex was confirmed by x-ray crystallography. The complexmore » crystallized in a monoclinic crystal system with P2(1)/n space group and cell dimensions of a = 12.2029(8) Å, b = 11.4010(7) Å, c = 14.4052(9) Å and β = 102.414(2)°. The compound was further characterized by mass spectrometry, CHN elemental analysis, infrared and UV-visible spectroscopy and the results concurred with the x-ray structure. The presence of d-d transition at 671 nm (ε = 116 dm{sup 3} mol{sup −1} cm{sup −1}) supports the presence of Cu(II) centres.« less

Acylphloroglucinol Derivatives from the South African Helichrysum niveum and Their Biological Activities.

PubMed

Popoola, Olugbenga K; Marnewick, Jeanine L; Rautenbach, Fanie; Iwuoha, Emmanuel I; Hussein, Ahmed A

2015-09-18

Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1-3) and six known (4-10) acylphloroglucinols alongside a known dialcohol triterpene (11). The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate)-phloroglucinol (helinivene A, 1), 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl)-phloroglucinol (helinivene B, 2), 8-(2-methylpropanone)-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3), 1-(2-methylbutanone)-4-O-prenyl-phloroglucinol (4), 1-(2-methylpropanone)-4-O-prennyl-phloroglucinol (5), 1-(butanone)-3-prenyl-phloroglucinol (6), 1-(2-methylbutanone)-3-prenyl-phloroglucinol (7), 1-butanone-3-(3-methylbut-2-enylacetate)-phloroglucinol (8), 1-(2-methylpropanone)-3-prenylphloroglucinol (9), caespitate (10), and 3β-24-dihydroxyterexer-14-ene (11). Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2) when measured as oxygen radicals absorbance capacity (ORAC), ferric-ion reducing antioxidant power (FRAP), trolox equivalent absorbance capacity (TEAC) and including the inhibition of Fe(2+)-induced lipid peroxidation (IC50 = 5.12 ± 0.90; 3.55 ± 1.92) µg/mL, while anti-tyrosinase activity at IC50 = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors.

Inhibitory properties of the antibothropic complex from the South American opossum (Didelphis marsupialis) serum.

PubMed

Neves-Ferreira, A G; Perales, J; Ovadia, M; Moussatché, H; Domont, G B

1997-06-01

The South American opossum Didelphis marsupialis is known to be highly resistant to snake envenomation. In this paper it is shown that the opossum serum inhibits haemorrhage induced by both Crotalinae and Viperinae venoms. Tested against Bothrops jararaca (jararaca) venom, the antibothropic complex (ABC) isolated from the opossum serum was at least six times more antihaemorrhagic than the commercial antivenom. ABC showed no proteolytic activity by itself and was not hydrolysed by the venom. It inhibited the hydrolysis of casein by B. jararaca venom, but did not inhibit its hydrolytic activities upon N alpha-benzoyl-L-arginine ethyl ester (BAEE) and N alpha-benzoyl-DL-arginine p-nitroanilide (BAPNA). The inhibitor did not interfere with trypsin and bacterial collagenase activities on BAPNA and N-(3-[2-furyl]acryloyl)-Leu-Gly-Pro-Ala (FALGPA), respectively. It reduced chymotrypsin hydrolysis of N-acetyl-L-tyrosine ethyl ester (ATEE) because ABC is also a substrate for this enzyme. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, B. jararaca venom preferentially degraded fibrinogen A alpha-chain and fibrin alpha-chain. Tested on extracellular matrix proteins, the venom hydrolysed collagen IV, gelatins I and V, laminin and fibronectin, besides depolimerizing collagen I alpha-chain dimers. Fibrillar collagen V was not digested. These hydrolyses were inhibited by ABC and by EDTA. Our results show that the antibothropic complex is a venom metalloproteinase inhibitor, which could, at least partially, account for its antihaemorrhagic activity. Electrophoretic evidence indicated non-covalent complex formation between the antihaemorrhagic factor and component(s) of B. jararaca venom.

Functionalized β-cyclodextrin based potentiometric sensor for naproxen determination.

PubMed

Lenik, Joanna; Łyszczek, Renata

2016-04-01

Potentiometric sensors based on neutral β-cyclodextrins: (2-hydroxypropyl)-β-cyclodextrin, heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin, heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin and anionic β-cyclodextrin: (2-hydroxy-3-N,N,N-trimethylamino)propyl-β-cyclodextrin chloride for naproxen are described. Inclusion complexes of naproxen with the above-mentioned cyclodextrins were studied using IR spectroscopy. The electrode surface was made from PVC membranes doped with the appropriate β-cyclodextrin as ionophores and quaternary ammonium chlorides as positive charge additives that were dispersed in plasticizers. The optimum membrane contains heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin, o-nitrophenyloctyl ether and tetraoctyl ammonium chloride as a lipophilic salt. The electrode is characterized by a Nernstian response slope of -59.0 ± 0.5 mV decade(-1) over the linear range of 5.0 × 10(-5)-1.0 × 10(-2) mol L(-1) and the detection limit 1.0 × 10(-5) mol L(-1), as well as the response time 10s. It can be used in the pH range 6.2-8.5 for 10 months without any considerable deterioration. Incorporation of β-cyclodextrins improved the electrode selectivity towards naproxen ions from several inorganic and organic interferents and some common drug excipients due to concovalent interactions (host molecule-guest molecule). The notable advantages of the naproxen-selective electrode include its high sensitivity, high selectivity, cost-effectiveness as well as accurate and comfortable application in drug analysis and milk samples. Copyright © 2015. Published by Elsevier B.V.

Molecular modeling of methyl-α-Neu5Ac analogues docked against cholera toxin--a molecular dynamics study.

PubMed

Blessy, J Jino; Sharmila, D Jeya Sundara

2015-02-01

Molecular modeling of synthetic methyl-α-Neu5Ac analogues modified in C-9 position was investigated by molecular docking and molecular dynamics (MD) simulation methods. Methyl-α-Neu5Ac analogues were docked against cholera toxin (CT) B subunit protein and MD simulations were carried out for three Methyl-α-Neu5Ac analogue-CT complexes (30, 10 and 10 ns) to estimate the binding activity of cholera toxin-Methyl-α-Neu5Ac analogues using OPLS_2005 force field. In this study, direct and water mediated hydrogen bonds play a vital role that exist between the methyl-α-9-N-benzoyl-amino-9-deoxy-Neu5Ac (BENZ)-cholera toxin active site residues. The Energy plot, RMSD and RMSF explain that the simulation was stable throughout the simulation run. Transition of phi, psi and omega angle for the complex was calculated. Molecular docking studies could be able to identify the binding mode of methyl-α-Neu5Ac analogues in the binding site of cholera toxin B subunit protein. MD simulation for Methyl-α-9-N-benzoyl-amino-9-deoxy-Neu5Ac (BENZ), Methyl-α-9-N-acetyl-9-deoxy-9-amino-Neu5Ac and Methyl-α-9-N-biphenyl-4-acetyl-deoxy-amino-Neu5Ac complex with CT B subunit protein was carried out, which explains the stable nature of interaction. These methyl-α-Neu5Ac analogues that have computationally acceptable pharmacological properties may be used as novel candidates for drug design for cholera disease.

Semi- and thiosemicarbazide Mn(II) complexes: Characterization, DFT and biological studies

NASA Astrophysics Data System (ADS)

Yousef, T. A.; Alduaij, O. K.; Ahmed, Sara F.; Abu El-Reash, G. M.; El-Gammal, O. A.

2016-09-01

One NO and two NOS donor ligands have been prepared by addition ethanolic suspension of 2-hydrazino-2-oxo-N-phenyl-acetamide to phenyl isocyanate (H2PAPS), phenyl isothiocyanate (H2PAPT) and benzoyl isothiocyanate (H2PABT). The Mn (II) complexes were prepared from the chloride salt and characterized by conventional techniques. The isolated complexes were assigned the formulaes, [Mn(HPAPS)2], [Mn(HPAPT)Cl] and [Mn(HPABT)Cl(H2O)2], respectively. The IR study of ligands and their complexes shows that H2PAPS behaves as a mononegative tridentate via both CO of hydrazide moiety in keto and deprotonated enol form and CN (azomethine) due to enolization of CO cyanate moiety without deprotonation. H2PAPT behaves as mononegative tridentate via CO of hydrazide moiety, deprotonated thiol CS and NH group. Finally H2PABT behaves as mononegative tridentate via deprotonated enolized CO of hydrazide moiety, CO of benzoyl moiety and NH group. The IR spectra of ligands from DFT calculations are compared with those obtained experimentally. Also, HOMO, LUMO, the bond lengths, bond angles, and dipole moments have been calculated. The calculated HOMO-LUMO energy gap reveals that charge transfer occurs within the molecule. The binding energy values display the high stability of complexes. The kinetic and thermodynamic parameters were determined by Coats-Redfern and Horowitz-Metzger methods. The antibacterial activities were also tested against Bacillus subtilis and Escherichia coli bacteria. Finally, the antitumor activities of the Ligands and their Mn(II) complexes have been evaluated against liver (HePG2) and breast (MCF-7) cancer cells.

Residual antibacterial activity of dog hairs after therapy with antimicrobial shampoos.

PubMed

Kloos, Isabell; Straubinger, Reinhard K; Werckenthin, Christiane; Mueller, Ralf S

2013-04-01

Topical antimicrobial treatment for canine pyoderma is becoming increasingly important, but little is known about the mechanism of action and persistence of activity of antimicrobial shampoos. To determine the residual antimicrobial activity on canine hairs treated with antimicrobial shampoos. Forty-two dogs from a research institution. Dogs were treated with six different shampoos and the combination of one shampoo and conditioner containing benzoyl peroxide, chlorhexidine in different concentrations (0.8, 2, 3 and 4%), ethyl lactate and miconazole twice weekly for 2 weeks. A shampoo vehicle without antimicrobial ingredients was used as the control. Hairs were collected immediately after and 2, 4 and 7 days after the last shampoo therapy and placed onto an agar plate streaked with Staphylococcus pseudintermedius. After incubation, the growth inhibition zone around the hair shafts was measured. The largest zone of inhibition of bacterial growth was seen after shampoos containing 2 and 3% chlorhexidine and the combination of chlorhexidine shampoo and conditioner. The zone of inhibition was smaller with the shampoos containing 0.8 and 4% chlorhexidine. There was no difference between the inhibition zones post-treatment with benzoyl peroxide, ethyl lactate and control. The efficacy of a shampoo is dependent not only on the concentration of the active ingredients but also on the shampoo formulation. Hair shafts treated with shampoos containing 2 and 3% chlorhexidine and the combination of shampoo and conditioner inhibited bacterial growth significantly and seem suitable to treat canine bacterial pyoderma. © 2013 The Authors. Veterinary Dermatology © 2013 ESVD and ACVD.

Preparation and characterization of (St-DVB-MAA) ion exchange resins

NASA Astrophysics Data System (ADS)

Jiang, Shanquan; Sun, Xiangwei; Ling, Lixing; Wang, Shumin; Wu, Wufeng; Cheng, Shihong; Hu, Yue; Zhong, Chunyan

2017-08-01

In this paper, used polyvinyl alcohol as dispersing agent, Benzoyl peroxide as initiator of polymerization, Divinyl benzene as cross-linking agent, Styrene and 2-Methylpropenoic acid as monomer, ion exchange resin (copolymer of St-DVB-MAA)were prepared by suspension polymerization on 80°C. The structures, components and properties of the prepared composite micro gels were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA). The experiment of ion exchange was conducted by resin to deal with copper ions in the solution. The result showed that performance of the ion exchange capacity was excellent, which impacted by pH.

Solution-Phase Synthesis of a Tricyclic Pyrrole-2-Carboxamide Discovery Library Applying a Stetter-Paal-Knorr Reaction Sequence

PubMed Central

Iyer, Pravin S.; Fodor, Matthew D.; Coleman, Claire M.; Twining, Leslie A.; Mitasev, Branko

2012-01-01

The solution phase synthesis of a discovery library of 178 tricyclic pyrrole-2-carboxamides was accomplished in nine steps and seven purifications starting with three benzoyl protected amino acid methyl esters. Further diversity was introduced by two glyoxaldehydes and forty-one primary amines. The combination of Pauson-Khand, Stetter and microwave assisted Paal Knorr reactions was applied as a key sequence. The discovery library was designed with the help of QikProp 2.1 and physicochemical data are presented for all pyrroles. Library members were synthesized and purified in parallel and analyzed by LC-MS. Selected compounds were fully characterized. PMID:16677007

Separation of actinides from lanthanides

DOEpatents

Smith, B.F.; Jarvinen, G.D.; Ryan, R.R.

1988-03-31

An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form is described. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4- dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

Separation of actinides from lanthanides

DOEpatents

Smith, Barbara F.; Jarvinen, Gordon D.; Ryan, Robert R.

1989-01-01

An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

A green and bio-inspired process to afford durable anti-biofilm properties to stainless steel.

PubMed

Faure, E; Vreuls, C; Falentin-Daudré, C; Zocchi, G; Van de Weerdt, C; Martial, J; Jérôme, C; Duwez, A-S; Detrembleur, C

2012-01-01

A bio-inspired durable anti-biofilm coating was developed for industrial stainless steel (SS) surfaces. Two polymers inspired from the adhesive and cross-linking properties of mussels were designed and assembled from aqueous solutions onto SS surfaces to afford durable coatings. Trypsin, a commercially available broad spectrum serine protease, was grafted as the final active layer of the coating. Its proteolytic activity after long immersion periods was demonstrated against several substrata, viz. a synthetic molecule, N-α-benzoyl-DL-arginine-p-nitroanilide hydrochloride (BAPNA), a protein, FTC-casein, and Gram-positive biofilm forming bacterium Staphylococcus epidermidis.

Generation of hazardous methyl azide and its application to synthesis of a key-intermediate of picarbutrazox, a new potent pesticide in flow.

PubMed

Ichinari, Daisuke; Nagaki, Aiichiro; Yoshida, Jun-Ichi

2017-12-01

Generation and reactions of methyl azide (MeN 3 ) were successfully performed by using a flow reactor system, demonstrating that the flow method serves as a safe method for handling hazardous explosive methyl azide. The reaction of NaN 3 and Me 2 SO 4 in a flow reactor gave a MeN 3 solution, which was used for Huisgen reaction with benzoyl cyanide in a flow reactor after minimal washing. The resulting 1-methyl-5-benzoyltetrazole serves as a key intermediate of picarbutrazox (IX), a new potent pesticide. Copyright © 2017. Published by Elsevier Ltd.

Enzymatic synthesis of dithiolopyrrolone antibiotics using cell-free extract of Saccharothrix algeriensis NRRL B-24137 and biochemical characterization of two pyrrothine N-acyltransferases in this extract.

PubMed

Saker, Safwan; Almousa Almaksour, Ziade; Chorin, Anne-Claire; Lebrihi, Ahmed; Mathieu, Florence

2014-01-01

Saccharothrix algeriensis NRRL B-24137 produces naturally different dithiolopyrrolone derivatives. The enzymatic activity of pyrrothine N-acyltransferase was determined to be responsible for the transfer of an acyl group from acyl-CoA to pyrrothine core. This activity was also reported to be responsible for the diversity of the dithiolopyrrolone derivatives. Based on this fact, nine dithiolopyrrolone derivatives were produced in vitro via the crude extract of Sa. algeriensis. Three of them have never been obtained before by natural fermentation: acetoacetyl-pyrrothine, hydroxybutyryl-pyrrothine, and dimethyl thiolutin (holomycin). Two acyltransferase activities, acetyltransferase and benzoyltransferase catalyzing the incorporation of linear and cyclic acyl groups to the pyrrothine core, respectively, were biochemically characterized in this crude extract. The first one is responsible for formation of acetyl-pyrrothine and the second for benzoyl-pyrrothine. Both enzymes were sensitive to temperature changes: For example, the loss of acetyltransferase and benzoyltransferase activity was 53% and 80% respectively after pre-incubation of crude extract for 60 min at 20°C. The two enzymes were more active in neutral and basal media (pH 7-10) than in the acidic one (pH 3-6). The optimum temperature and pH of acetyltransferase were 40°C and 7, with a Km value of 7.9 μM and a Vmax of 0.63 μM/min when acetyl-CoA was used as limited substrate. Benzoyltransferase had a temperature and a pH optimum at 55°C and 9, a Km value of 14.7 μM, and a Vmax of 0.67 μM/min when benzoyl- CoA was used as limited substrate.

β-Nicotinamide Adenine Dinucleotide (β-NAD) Inhibits ATP-Dependent IL-1β Release from Human Monocytic Cells.

PubMed

Hiller, Sebastian Daniel; Heldmann, Sarah; Richter, Katrin; Jurastow, Innokentij; Küllmar, Mira; Hecker, Andreas; Wilker, Sigrid; Fuchs-Moll, Gabriele; Manzini, Ivan; Schmalzing, Günther; Kummer, Wolfgang; Padberg, Winfried; McIntosh, J Michael; Damm, Jelena; Zakrzewicz, Anna; Grau, Veronika

2018-04-10

While interleukin-1β (IL-1β) is a potent pro-inflammatory cytokine essential for host defense, high systemic levels cause life-threatening inflammatory syndromes. ATP, a stimulus of IL-1β maturation, is released from damaged cells along with β-nicotinamide adenine dinucleotide (β-NAD). Here, we tested the hypothesis that β-NAD controls ATP-signaling and, hence, IL-1β release. Lipopolysaccharide-primed monocytic U937 cells and primary human mononuclear leukocytes were stimulated with 2'(3')- O -(4-benzoyl-benzoyl)ATP trieethylammonium salt (BzATP), a P2X7 receptor agonist, in the presence or absence of β-NAD. IL-1β was measured in cell culture supernatants. The roles of P2Y receptors, nicotinic acetylcholine receptors (nAChRs), and Ca 2+ -independent phospholipase A2 (iPLA2β, PLA2G6) were investigated using specific inhibitors and gene-silencing. Exogenous β-NAD signaled via P2Y receptors and dose-dependently (IC 50 = 15 µM) suppressed the BzATP-induced IL-1β release. Signaling involved iPLA2β, release of a soluble mediator, and nAChR subunit α9. Patch-clamp experiments revealed that β-NAD inhibited BzATP-induced ion currents. In conclusion, we describe a novel triple membrane-passing signaling cascade triggered by extracellular β-NAD that suppresses ATP-induced release of IL-1β by monocytic cells. This cascade links activation of P2Y receptors to non-canonical metabotropic functions of nAChRs that inhibit P2X7 receptor function. The biomedical relevance of this mechanism might be the control of trauma-associated systemic inflammation.

An easily regenerable enzyme reactor prepared from polymerized high internal phase emulsions

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

Ruan, Guihua, E-mail: guihuaruan@hotmail.com; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541004; Wu, Zhenwei

A large-scale high-efficient enzyme reactor based on polymerized high internal phase emulsion monolith (polyHIPE) was prepared. First, a porous cross-linked polyHIPE monolith was prepared by in-situ thermal polymerization of a high internal phase emulsion containing styrene, divinylbenzene and polyglutaraldehyde. The enzyme of TPCK-Trypsin was then immobilized on the monolithic polyHIPE. The performance of the resultant enzyme reactor was assessed according to the conversion ability of N{sub α}-benzoyl-L-arginine ethyl ester to N{sub α}-benzoyl-L-arginine, and the protein digestibility of bovine serum albumin (BSA) and cytochrome (Cyt-C). The results showed that the prepared enzyme reactor exhibited high enzyme immobilization efficiency and fast andmore » easy-control protein digestibility. BSA and Cyt-C could be digested in 10 min with sequence coverage of 59% and 78%, respectively. The peptides and residual protein could be easily rinsed out from reactor and the reactor could be regenerated easily with 4 M HCl without any structure destruction. Properties of multiple interconnected chambers with good permeability, fast digestion facility and easily reproducibility indicated that the polyHIPE enzyme reactor was a good selector potentially applied in proteomics and catalysis areas. - Graphical abstract: Schematic illustration of preparation of hypercrosslinking polyHIPE immobilized enzyme reactor for on-column protein digestion. - Highlights: • A reactor was prepared and used for enzyme immobilization and continuous on-column protein digestion. • The new polyHIPE IMER was quite suit for protein digestion with good properties. • On-column digestion revealed that the IMER was easy regenerated by HCl without any structure destruction.« less

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

Ryan, J.W.; Anderson, D.R.

Eye tissues contain kininase activities, including an angiotensin converting enzyme (ACE)-like activity. The authors have begun further to characterize the ACE-like activity and to examine for another reputed kininase, carboxypeptidase N (CPN). Homogenates of tissues of 6 cat eyes and paired plasmas were assayed for ACE using 3 acyl-tripeptide substrates, /sup 3/H-benzoylated F-A-P, F-G-P and A-G-P (respectively, BFAP, BFGP and BAGP). CPN was assayed using /sup 3/H-benzoyl-A-R. All eye tissues and fluids contained ACE- and CPN-like activities. The ACE activity was clearly owing to ACE: relative values of Kc/Km for BFAP, BFGP and BAGP were those for pure ACE (2.213,more » 1.751 and 1.0); reactivities with inhibitors were as expected (Ki for captopril, MK 422 and RAC-X-65: 2.7, 0.62 and 0.31 nM). EDTA inhibited both ACE and CPN (I/sub 50/'s: 43 and 47 ..mu..M). CPN activity was inhibited by 2-mercaptomethyl-3-guanidinoethylthiopropionate (Ki 2.4 nM). However, distributions of the two enzymes differed markedly. Virtually all tissues contained ACE at specific activities higher than that of plasma. Specific activities appeared to be a function of tissue vascularity (for choroid, ciliary body, iris, retina and plasma: 7.31, 2.57, 1.98, 1.53 and 0.21 pmol/mg protein). Only iris contained more CPN that did plasma (23.0 v. 7.21 pmol/mg protein). The tissue distribution of ACE is that expected for an endothelial-associated enzyme. Plasma may be the major source of CPN in eye tissues other than iris.« less

2-Acylpyrroles as mono-anionic O,N-chelating ligands in silicon coordination chemistry.

PubMed

Kämpfe, Alexander; Brendler, Erica; Kroke, Edwin; Wagler, Jörg

2014-07-21

Kryptopyrrole (2,4-dimethyl-3-ethylpyrrole) was acylated with, for example, benzoyl chloride to afford 2-benzoyl-3,5-dimethyl-4-ethylpyrrole (L(1)H). With SiCl4 this ligand reacts under liberation of HCl and formation of the complex L(1)2SiCl2. In related reactions with HSiCl3 or H2SiCl2, the same chlorosilicon complex is formed under liberation of HCl and H2 or liberation of H2, respectively. The chlorine atoms of L(1)2SiCl2 can be replaced by fluoride and triflate using ZnF2 and Me3Si-OTf, respectively. The use of a supporting base (triethylamine) is required for the complexation of phenyltrichlorosilane and diphenyldichlorosilane. The complexes L(1)2SiCl2, L(1)2SiF2, L(1)2Si(OTf)2, L(1)2SiPhCl, and L(1)2SiPh2 exhibit various configurations of the octahedral silicon coordination spheres (i.e. cis or trans configuration of the monodentate substituents, different orientations of the bidentate chelating ligands relative to each other). Furthermore, cationic silicon complexes L(1)3Si(+) and L(1) SiPh(+) were synthesized by chloride abstraction with GaCl3. In contrast, reaction of L(1)2SiCl2 with a third equivalent of L(1)H in the presence of excess triethylamine produced a charge-neutral hexacoordinate Si complex with a new tetradentate chelating ligand which formed by Si-templated C-C coupling of two ligands L(1). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Versatility of azelaic acid 15% gel in treatment of inflammatory acne vulgaris.

PubMed

Thiboutot, Diane

2008-01-01

Azelaic acid (AzA) 15% gel is approved for the treatment of rosacea in the US, but also has approval for the treatment of acne vulgaris in many European countries where it has demonstrated success. Two randomized, multicenter, controlled clinical trials compared the effects of AzA 15% gel with those of topical benzoyl peroxide 5% or topical clindamycin 1%, all using a twice-daily dosing regimen. The primary endpoint in the intent-to-treat analysis was a reduction in inflammatory papules and pustules. AzA 15% gel resulted in a 70% to 71% median reduction of facial papules and pustules compared with a 77% reduction with benzoyl peroxide 5% gel and a 63% reduction with clindamycin. AzA 15% gel was well-tolerated. In addition, a 1-year European observational study conducted by dermatologists in private practice evaluated the safety and efficacy of AzA 15% gel used as monotherapy or in combination with other agents in more than 1200 patients with acne. Most physicians (81.9%) described an improvement in patients' symptoms after an average of 34.6 days, and 93.9% of physicians reported patient improvement after an average of 73.1 days. Both physicians and patients assessed AzA 15% gel to be effective with 74% of patients being "very satisfied" at the end of therapy. AzA 15% gel was considered "well-tolerated" or "very well-tolerated" by 95.7% of patients. The majority of patients were more satisfied with AzA than with previous therapies. AzA 15% gel represents a new therapeutic option for the treatment of acne vulgaris.

Microfluorimetric analysis of a purinergic receptor (P2X7) in GH4C1 rat pituitary cells: effects of a bioactive substance produced by Pfiesteria piscicida.

PubMed Central

Melo, A C; Moeller, P D; Glasgow, H; Burkholder, J M; Ramsdell, J S

2001-01-01

Pfiesteria piscicida Steidinger & Burkholder is a toxic dinoflagellate that leads to fish and human toxicity. It produces a bioactive substance that leads to cytotoxicity of GH4C1 rat pituitary cells. Extracellular adenosine 5'-triphosphate (ATP) acting on P2X7 purinergic receptors induces the formation of a nonselective cation channel, causing elevation of the cytosolic free calcium followed by a characteristic permeabilization of the cell to progressively larger ions and subsequent cell lysis. We investigated whether GH4C1 rat pituitary cells express functional P2X7 receptors, and if so, are they activated by a bioactive substance isolated from toxic P. piscicida cultures. We tested the selective agonist 2'-3'-O-(benzoyl-4-benzoyl)-ATP (BzATP) and antagonists piridoxalphosphate-6-azophenyl-2'-4'-disulfonic acid (PPADS) and oxidized-ATP (oxATP) using elevated cytosolic free calcium in Fura-2 loaded cells, and induced permeability of these cells to the fluorescent dye YO-PRO-1 as end points. We demonstrated that in GH4C1 cells, BzATP induces both the elevation of cytosolic free calcium and the permeabilization of the cell membrane. ATP-induced membrane permeabilization was inhibited by PPADS reversibly and by oxATP irreversibly. The putative Pfiesteria toxin (pPfTx) also elevated cytosolic free calcium in Fura-2 in GH4C1 cells and increased the permeability to YO-PRO-1 in a manner inhibited fully by oxATP. This study indicates that GH4C1 cells express a purinoceptor with characteristics consistent with the P2X7 subtype, and that pPfTx mimics the kinetics of cell permeabilization by ATP. PMID:11677182

Growth Substrate- and Phase-Specific Expression of Biphenyl, Benzoate, and C1 Metabolic Pathways in Burkholderia xenovorans LB400

PubMed Central

Denef, V. J.; Patrauchan, M. A.; Florizone, C.; Park, J.; Tsoi, T. V.; Verstraete, W.; Tiedje, J. M.; Eltis, L. D.

2005-01-01

Recent microarray experiments suggested that Burkholderia xenovorans LB400, a potent polychlorinated biphenyl (PCB)-degrading bacterium, utilizes up to three apparently redundant benzoate pathways and a C1 metabolic pathway during biphenyl and benzoate metabolism. To better characterize the roles of these pathways, we performed quantitative proteome profiling of cells grown on succinate, benzoate, or biphenyl and harvested during either mid-logarithmic growth or the transition between the logarithmic and stationary growth phases. The Bph enzymes, catabolizing biphenyl, were ∼16-fold more abundant in biphenyl- versus succinate-grown cells. Moreover, the upper and lower bph pathways were independently regulated. Expression of each benzoate pathway depended on growth substrate and phase. Proteins specifying catabolism via benzoate dihydroxylation and catechol ortho-cleavage (ben-cat pathway) were approximately an order of magnitude more abundant in benzoate- versus biphenyl-grown cells at the same growth phase. The chromosomal copy of the benzoyl-coenzyme A (CoA) (boxC) pathway was also expressed during growth on biphenyl: BoxC proteins were approximately twice as abundant as Ben and Cat proteins under these conditions. By contrast, proteins of the megaplasmid copy of the benzoyl-CoA (boxM) pathway were only detected in transition-phase benzoate-grown cells. Other proteins detected at increased levels in benzoate- and biphenyl-grown cells included general stress response proteins potentially induced by reactive oxygen species formed during aerobic aromatic catabolism. Finally, C1 metabolic enzymes were present in biphenyl-grown cells during transition phase. This study provides insights into the physiological roles and integration of apparently redundant catabolic pathways in large-genome bacteria and establishes a basis for investigating the PCB-degrading abilities of this strain. PMID:16291673

Chemical Constituents with Proprotein Convertase Subtilisin/Kexin Type 9 mRNA Expression Inhibitory Activity from Dried Immature Morus alba Fruits.

PubMed

Pel, Pisey; Chae, Hee-Sung; Nhoek, Piseth; Kim, Young-Mi; Chin, Young-Won

2017-07-05

Phytochemical investigation for a chloroform-soluble extract of dried Morus alba fruits, selected by proprotein convertase subtilisin-kexin type 9 (PCSK9) mRNA expression monitoring assay in HepG2 cells, led to the isolation of a new benzofuran, isomoracin D (1), and a naturally occurring compound, N-(N-benzoyl-l-phenylalanyl)-l-phenylalanol (2), along with 13 known compounds (3-15). All of the structures were established by NMR spectroscopic data as well as MS analysis. Of the isolates, moracin C (7) was found to inhibit PCSK9 mRNA expression with an IC 50 value of 16.8 μM in the HepG2 cells.

Crystal structure of 1-ferrocenyl-2-(4-methyl-benzo-yl)spiro-[11H-pyrrolidizine-3,11'-indeno[1,2-b]quinoxaline].

PubMed

Chandralekha, Kuppan; Gavaskar, Deivasigamani; Sureshbabu, Adukamparai Rajukrishnan; Lakshmi, Srinivasakannan

2014-09-01

In the title compound, [Fe(C5H5)(C34H28N3O)], the four-fused-rings system of the 11H-indeno-[1,2-b]quinoxaline unit is approximately planar [maximum deviation = 0.167 (4) Å] and forms a dihedral angle of 37.25 (6)° with the plane of the benzene ring of the methyl-benzoyl group. Both pyrrolidine rings adopt a twist conformation. An intra-molecular C-H⋯O hydrogen bond is observed. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and weak C-H⋯π inter-actions, forming double chains extending parallel to the c axis.

Diastereoselective preparation of (R)- and (S)-2-methoxy-2-phenylpent-3-ynoic acids and their use as reliable chiral derivatizing agents.

PubMed

Pérez-Estrada, Salvador; Joseph-Nathan, Pedro; Jiménez-Vázquez, Hugo A; Medina-López, Manuel E; Ayala-Mata, Francisco; Zepeda, L Gerardo

2012-02-17

Benzoyl-S,O-acetals 1a and 1b were used as chiral auxiliaries to achieve the diastereoselective preparation of both enantiomers of 2-methoxy-2-phenylpent-3-ynoic acids (MPPAs). The latter were condensed with several chiral secondary alcohols and some primary amines to evaluate their potential as chiral derivatizing agents (CDAs). The (1)H NMR spectra of the corresponding esters and amides showed strong consistency with the absolute configuration of the carbinol and amine moieties, whose observed ΔδL(1) and ΔδL(2) values were in the ranges of 0.1-0.4 and 0.02-0.12 ppm, respectively.

Polyimides containing carbonyl and ether connecting groups - II

NASA Technical Reports Server (NTRS)

Hergenrother, P. M.; Havens, S. J.

1989-01-01

In a study of polyimides containing carbonyl and ether connecting groups between aromatic rings, several new polyimides were prepared and characterized. A few of these polymers were semicrystalline. Glass transition temperatures ranged from 164 to 258 C, and crystalline melt temperatures were observed between 350 and 424 C. The semicrystalline polyimide from the reaction of 3.3',4,4'-benzophenonetetracarboxylic dianhydride and 1,3-bis(4-aminophenoxy-4'-benzoyl)benzene provided transparent orange films with excellent tensile properties, exceptional resistance to solvents and strong base, and high thermooxidative stability. In addition, this polyimide provided excellent adhesive strength for joining titanium (6Al-4V) to titanium.

Polycatecholamide chelating agents

DOEpatents

Weitl, F.L.; Raymond, K.N.

1984-04-10

Novel polybenzamide compounds useful for in vitro or in vivo chelation are described. The compounds have the formula given in patent. Polyamines are reacted with 2,3-dimethoxy benzoyl chloride unsubstituted or substituted with SO[sub 3]H, SO[sub 3]M, NO[sub 2], CO[sub 2]H or CO[sub 2]M as desired is reacted with a polyamine in an inert solvent then demethylated with BBr[sub 3] or BCl[sub 3] in an inert solvent. Where compounds symmetrically substituted on the terminal N's are desired, the polyamine is first reductively alkylated by reaction with an aldehyde or ketone and the resulting Schiff base is hydrogenated. No Drawings

Novel polycatecholamide chelating agents

DOEpatents

Weitl, F.L.; Raymond, K.N.

1981-08-24

Novel polybenzamide compounds useful for in vitro or in vivo chelation are described. Formulas of the compounds are given. To prepare them polyamines are reacted with 2,3-dimethoxy benzoyl chloride unsubstituted or substituted with SO/sub 3/H, SO/sub 3/M, NO/sub 2/, CO/sub 2/H or CO/sub 2/M as desired is reacted with a polyamine in an inert solvent then demethylated with BBr/sub 3/ or BCl/sub 3/ in an inert solvent. Where compounds symmetrically substituted on the terminal N's are desired, the polyamine is first reductively alkylated by reaction with an aldehyde or ketone and the resulting Schiff base is hydrogenated.

Polycatecholamide chelating agents

DOEpatents

Weitl, Frederick L.; Raymond, Kenneth N.

1984-01-01

Novel polybenzamide compounds useful for in vitro or in vivo chelation are described. The compounds have the formula ##STR1## Polyamines are reacted with 2,3-dimethoxy benzoyl chloride unsubstituted or substituted with SO.sub.3 H, SO.sub.3 M, NO.sub.2, CO.sub.2 H or CO.sub.2 M as desired is reacted with a polyamine in an inert solvent then demethylated with BBr.sub.3 or BCl.sub.3 in an inert solvent. Where compounds symmetrically substituted on the terminal N's are desired, the polyamine is first reductively alkylated by reaction with an aldehyde or ketone and the resulting Schiff base is hydrogenated.

Structural studies of 4-aminoantipyrine derivatives

NASA Astrophysics Data System (ADS)

Cunha, Silvio; Oliveira, Shana M.; Rodrigues, Manoel T.; Bastos, Rodrigo M.; Ferrari, Jailton; de Oliveira, Cecília M. A.; Kato, Lucília; Napolitano, Hamilton B.; Vencato, Ivo; Lariucci, Carlito

2005-10-01

Reaction of 4-aminoantipyrine with acetylacetone, ethyl acetoacetate, benzoyl isothiocyanate, phenyl isothiocyanate, maleic anhydride and methoxymethylene Meldrum's acid afforded a series of new antipyrine derivatives. The antibacterial activity of the synthesized compounds against Micrococcus luteus ATCC 9341, Staphilococcus aureus ATCC 29737, and Escherichia coli ATCC 8739 was evaluated and the minimal inhibitory concentration determined. Modest activity was found only to the maleamic acid obtained from the reaction of 4-aminoantipyrine and maleic anhydride. 1H NMR investigation of this maleamic acid showed that it is slowly converted to the corresponding toxic maleimide. The structures of three derivatives were determined by X-ray diffraction analysis.

Redox-Active Star Molecules Incorporating the 4-Benzolypyridinium Cation: Implications for the Charge Transfer Efficiency Along Branches versus Across the Perimeter in Dendrimers

NASA Technical Reports Server (NTRS)

Yang, Jin-Hua; Rawashdeh, Abdel Monem M.; Oh, Woon Su; Sotiriou-Leventis, Chariklia; Leventis, Nicholas

2003-01-01

We report the redox properties of four star systems incorporating the 4-benzoyl-N-alkylpyridinium cation; the redox potential varies along the branches, but remains constant at fixed radii. Voltammetric analysis (cyclic voltammetry and differential pulse voltammetry) shows that only two of the three redox-active centers in the perimeter are electrochemically accessible during potential sweeps as slow as 20 mV/s and as fast as 10 V/s. On the contrary, both redox centers of a branch are accessible electrochemically within the same time frame. These results are discussed in terms of slow through-space charge transfer and the globular 3-D folding of the molecules.

Chemically linked metal-matrix nanocomposites of boron nitride nanosheets and silver as thermal interface materials

DOE PAGES

Nagabandi, N.; Yegin, C.; Feng, X.; ...

2018-01-31

Herein, novel hybrid nanocomposite thermal interface materials (TIMs) relying on the chemical linkage of silver, boron nitride nanosheets (BNNSs), and organic ligands are reported. These TIMs were prepared using a co-electrodeposition/chemisorption approach where the electrolytic reduction of silver ions into silver nano-/micro-crystals was coupled with the conjugation of ligand-coated nanosheets onto silver crystals. Furthermore, the influence of bond strength of silver/nanosheet links on the thermal, mechanical, and structural properties is investigated using a combination of techniques; including laser flash analysis, phase-sensitive transient thermoreflectance, nanoindentation, and electron microscopy. Internal nanostructure was found to be strongly dependent on the linker chemistry. Whilemore » the chemical grafting of 4-cyano-benzoyl chloride (CBC) and 2-mercapto-5-benzimidazole carboxylic acid (MBCA) on BNNSs led to the uniform distribution of functionalized-nanosheets in the silver crystal matrix, the physical binding of 4-bromo-benzoyl chloride (BBC) linkers on nanosheets caused the aggregation and phase separation. The thermal conductivity was 236-258 W/m-K and 306-321 W/m-K for physically and chemically conjugated TIMs, respectively, while their hardness varied from 495 to 400 MPa and from 240 to 360 MPa, respectively. The corresponding ratio of thermal conductivity to hardness, which is a critical parameter controlling the performance of TIMs, was ultrahigh for the chemically conjugated TIMs: 1.3x10-6 m2/K-s for MBCA-BNNS and 8.5x10-7 m2/K-s for CBC-BNNS. We anticipate that these materials can satisfy some of the emerging thermal management needs arising from the improved performance and efficiency, miniaturization, and/or high throughput of electronic devices, energy storage devices, energy conversion systems, light-emitting diodes, and telecommunication components.« less

Identification of a P2X7 receptor in GH(4)C(1) rat pituitary cells: a potential target for a bioactive substance produced by Pfiesteria piscicida.

PubMed Central

Kimm-Brinson, K L; Moeller, P D; Barbier, M; Glasgow, H; Burkholder, J M; Ramsdell, J S

2001-01-01

We examined the pharmacologic activity of a putative toxin (pPfTx) produced by Pfiesteria piscicida by characterizing the signaling pathways that induce the c-fos luciferase construct in GH(4)C(1) rat pituitary cells. Adenosine-5'-triphosphate (ATP) was determined to increase and, at higher concentrations, decrease luciferase activity in GH(4)C(1) rat pituitary cells that stably express c-fos luciferase. The inhibition of luciferase results from cytotoxicity, characteristic of the putative P. piscicida toxin (pPfTx). The actions of both pPfTx and ATP to induce c-fos luciferase were inhibited by the purinogenic receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). Further characterization of a P2X receptor on the GH(4)C(1) cell was determined by the analog selectivity of P2X agonists. The P2X1/P2X3 agonist alpha,beta-methylene ATP (alpha,beta-MeATP) failed to increase or decrease c-fos luciferase. However, the P2X7 agonist 2',3'-(4-benzoyl)benzoyl ATP (BzATP), which had a predominant cytotoxic effect, was more potent than ATP. Immunoblot analysis of GH(4)C(1) cell membranes confirmed the presence of a 70-kDa protein that was immunoreactive to an antibody directed against the carboxy-terminal domain unique to the P2X7 receptor. The P2X7 irreversible antagonist oxidized-ATP (oxATP) inhibited the action of ATP, BzATP, and pPfTx. These findings indicate that GH(4)C(1) cells express purinogenic receptors with selectivity consistent with the P2X7 subtype and that this receptor pathway mediates the induction of the c-fos luciferase reporter gene by ATP and the putative Pfiesteria toxin PMID:11401756

Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment.

PubMed

Rabus, Ralf; Boll, Matthias; Heider, Johann; Meckenstock, Rainer U; Buckel, Wolfgang; Einsle, Oliver; Ermler, Ulrich; Golding, Bernard T; Gunsalus, Robert P; Kroneck, Peter M H; Krüger, Martin; Lueders, Tillmann; Martins, Berta M; Musat, Florin; Richnow, Hans H; Schink, Bernhard; Seifert, Jana; Szaleniec, Maciej; Treude, Tina; Ullmann, G Matthias; Vogt, Carsten; von Bergen, Martin; Wilkes, Heinz

2016-01-01

naphthalene), W-cofactor-containing enzymes for reductive dearomatization of benzoyl-CoA (class II benzoyl-CoA reductase) in obligate anaerobes and addition of water to acetylene, fermentative formation of cyclohexanecarboxylate from benzoate, and methanogenic degradation of hydrocarbons. © 2016 S. Karger AG, Basel.

Chemically linked metal-matrix nanocomposites of boron nitride nanosheets and silver as thermal interface materials.

PubMed

Nagabandi, N; Yegin, C; Feng, X; King, C; Oh, J K; Scholar, E A; Narumanchi, S; Akbulut, M

2018-03-09

Herein, novel hybrid nanocomposite thermal interface materials (TIMs) relying on the chemical linkage of silver, boron nitride nanosheets (BNNSs), and organic ligands are reported. These TIMs were prepared using a co-electrodeposition/chemisorption approach where the electrolytic reduction of silver ions into silver nano-/micro-crystals was coupled with the conjugation of ligand-coated nanosheets onto silver crystals. Furthermore, the influence of the bond strength of silver/nanosheet links on the thermal, mechanical, and structural properties is investigated using a combination of techniques including laser flash analysis, phase-sensitive transient thermoreflectance, nanoindentation, and electron microscopy. The internal nanostructure was found to be strongly dependent on the linker chemistry. While the chemical grafting of 4-cyano-benzoyl chloride (CBC) and 2-mercapto-5-benzimidazole carboxylic acid (MBCA) on BNNSs led to the uniform distribution of functionalized-nanosheets in the silver crystal matrix, the physical binding of 4-bromo-benzoyl chloride linkers on nanosheets caused the aggregation and phase separation. The thermal conductivity was 236-258 W m -1 K and 306-321 W m -1 K for physically and chemically conjugated TIMs, respectively, while their hardness varied from 400-495 MPa and from 240 to 360 MPa, respectively. The corresponding ratio of thermal conductivity to hardness, which is a critical parameter controlling the performance of TIMs, was ultrahigh for the chemically conjugated TIMs: 1.3 × 10 -6 m 2 K -1 s for MBCA-BNNS and 8.5 × 10 -7 m 2 K -1 s for CBC-BNNS. We anticipate that these materials can satisfy some of the emerging thermal management needs arising from the improved performance and efficiency, miniaturization, and/or high throughput of electronic devices, energy storage devices, energy conversion systems, light-emitting diodes, and telecommunication components.

Chemically linked metal-matrix nanocomposites of boron nitride nanosheets and silver as thermal interface materials

NASA Astrophysics Data System (ADS)

Nagabandi, N.; Yegin, C.; Feng, X.; King, C.; Oh, J. K.; Scholar, E. A.; Narumanchi, S.; Akbulut, M.

2018-03-01

Herein, novel hybrid nanocomposite thermal interface materials (TIMs) relying on the chemical linkage of silver, boron nitride nanosheets (BNNSs), and organic ligands are reported. These TIMs were prepared using a co-electrodeposition/chemisorption approach where the electrolytic reduction of silver ions into silver nano-/micro-crystals was coupled with the conjugation of ligand-coated nanosheets onto silver crystals. Furthermore, the influence of the bond strength of silver/nanosheet links on the thermal, mechanical, and structural properties is investigated using a combination of techniques including laser flash analysis, phase-sensitive transient thermoreflectance, nanoindentation, and electron microscopy. The internal nanostructure was found to be strongly dependent on the linker chemistry. While the chemical grafting of 4-cyano-benzoyl chloride (CBC) and 2-mercapto-5-benzimidazole carboxylic acid (MBCA) on BNNSs led to the uniform distribution of functionalized-nanosheets in the silver crystal matrix, the physical binding of 4-bromo-benzoyl chloride linkers on nanosheets caused the aggregation and phase separation. The thermal conductivity was 236-258 W m-1 K and 306-321 W m-1 K for physically and chemically conjugated TIMs, respectively, while their hardness varied from 400-495 MPa and from 240 to 360 MPa, respectively. The corresponding ratio of thermal conductivity to hardness, which is a critical parameter controlling the performance of TIMs, was ultrahigh for the chemically conjugated TIMs: 1.3 × 10-6 m2 K-1 s for MBCA-BNNS and 8.5 × 10-7 m2 K-1 s for CBC-BNNS. We anticipate that these materials can satisfy some of the emerging thermal management needs arising from the improved performance and efficiency, miniaturization, and/or high throughput of electronic devices, energy storage devices, energy conversion systems, light-emitting diodes, and telecommunication components.

Chemically linked metal-matrix nanocomposites of boron nitride nanosheets and silver as thermal interface materials

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

Nagabandi, N.; Yegin, C.; Feng, X.

Herein, novel hybrid nanocomposite thermal interface materials (TIMs) relying on the chemical linkage of silver, boron nitride nanosheets (BNNSs), and organic ligands are reported. These TIMs were prepared using a co-electrodeposition/chemisorption approach where the electrolytic reduction of silver ions into silver nano-/micro-crystals was coupled with the conjugation of ligand-coated nanosheets onto silver crystals. Furthermore, the influence of bond strength of silver/nanosheet links on the thermal, mechanical, and structural properties is investigated using a combination of techniques; including laser flash analysis, phase-sensitive transient thermoreflectance, nanoindentation, and electron microscopy. Internal nanostructure was found to be strongly dependent on the linker chemistry. Whilemore » the chemical grafting of 4-cyano-benzoyl chloride (CBC) and 2-mercapto-5-benzimidazole carboxylic acid (MBCA) on BNNSs led to the uniform distribution of functionalized-nanosheets in the silver crystal matrix, the physical binding of 4-bromo-benzoyl chloride (BBC) linkers on nanosheets caused the aggregation and phase separation. The thermal conductivity was 236-258 W/m-K and 306-321 W/m-K for physically and chemically conjugated TIMs, respectively, while their hardness varied from 495 to 400 MPa and from 240 to 360 MPa, respectively. The corresponding ratio of thermal conductivity to hardness, which is a critical parameter controlling the performance of TIMs, was ultrahigh for the chemically conjugated TIMs: 1.3x10-6 m2/K-s for MBCA-BNNS and 8.5x10-7 m2/K-s for CBC-BNNS. We anticipate that these materials can satisfy some of the emerging thermal management needs arising from the improved performance and efficiency, miniaturization, and/or high throughput of electronic devices, energy storage devices, energy conversion systems, light-emitting diodes, and telecommunication components.« less

Venom from the snake Bothrops asper Garman. Purification and characterization of three phospholipases A2

PubMed Central

Anagón, Alejandro C.; Molinar, Ricardo R.; Possani, Lourival D.; Fletcher, Paul L.; Cronan, John E.; Julia, Jordi Z.

1980-01-01

The water-soluble venom of Bothrops asper Garman (San Juan Evangelista, Veracruz, México) showed 15 polypeptide bands on polyacrylamide-gel electrophoresis. This material exhibited phospholipase, hyaluronidase, N-benzoyl-l-arginine ethyl hydrolase, N-benzoyl-l-tyrosine ethyl hydrolase and phosphodiesterase activity, but no alkaline phosphatase or acid phosphatase activity. Fractionation on Sephadex G-75 afforded seven protein fractions, which were apparently less toxic than the whole venom (LD50=4.3μg/g mouse wt.). Subsequent separation of the phospholipase-positive fraction (II) on DEAE-cellulose with potassium phosphate buffers (pH7.55) gave several fractions, two being phospholipase-positive (II.6 and II.8). These fractions were further purified on DEAE-cellulose columns with potassium phosphate buffers (pH8.6). Fraction II.8.4 was rechromatographed in the same DEAE-cellulose column, giving a pure protein designated phospholipase 1. The fraction II.6.3 was further separated by gel disc electrophoresis yielding two more pure proteins designated phospholipase 2 and phospholipase 3. Analysis of phospholipids hydrolysed by these enzymes have shown that all three phospholipases belong to type A2. Amino acid analysis has shown that phospholipase A2 (type 1) has 97 residues with a calculated mol.wt. of 10978±11. Phospholipase A2 (type 2) has 96 residues with a mol.wt. of 10959±11. Phospholipase A2 (type 3) has 266 residues with 16 half-cystine residues and a calculated mol.wt of 29042±31. Automated Edman degradation showed the N-terminal sequence to be: Asx-Leu-Trp-Glx-Phe-Gly-Glx-Met-Met-Ser-Asx-Val- Met-Arg-Lys-Asx-Val-Val-Phe-Lys-Tyr-Leu- for phospholipase A2 (type 2). ImagesFig. 1. PMID:7387631

High temperature concrete composites containing organosiloxane crosslinked copolymers

DOEpatents

Zeldin, A.; Carciello, N.; Kukacka, L.; Fontana, J.

High temperature polymer concrete composites comprising about 10 to 30% by weight of a liquid monomer mixture is described. It consists essentially of an organosiloxane polymer crosslinked with an olefinically unsaturated monomer selected from the group consisting of styrene, methyl methacrylate, trimethylolpropane trimethacrylate, triallyl cyanurate, n-phenylmalimide, divinyl benzene and mixtures thereof. About 70 to 90% by weight of an inert inorganic filler system containing silica sand and portland cement, Fe/sub 2/O/sub 3/, carbon black or mixtures thereof. Optionally a free radical initiator such as di-tert-butyl peroxide, azobisisobyutyronitrile, benzoyl peroxide, lauryl peroxide and other organic peroxides are used to initiate crosspolymerization of the monomer mixture in the presence of the inorganic filler.

Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers.

PubMed

Stelescu, Maria-Daniela; Manaila, Elena; Craciun, Gabriela; Chirila, Corina

2017-07-11

Natural rubber composites filled with short natural fibers (flax and sawdust) were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger .

Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers

PubMed Central

Stelescu, Maria-Daniela; Manaila, Elena; Craciun, Gabriela; Chirila, Corina

2017-01-01

Natural rubber composites filled with short natural fibers (flax and sawdust) were prepared by blending procedure and the elastomer cross-linking was carried out using benzoyl peroxide. The microbial degradation of composites was carried out by incubating with Aspergillus niger recognized for the ability to grow and degrade a broad range of substrates. The extent of biodegradation was evaluated by weight loss and cross-linking degree study of composites after 2 months incubation in pure shake culture conditions. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) have proved to be precious and valuable instruments for morphological as well as structural characterization of the composites before and after incubation with Aspergillus niger. PMID:28773145

Synthesis and characterization of poly (benzyl trimethyl ammonium chloride) ionic polymer

NASA Astrophysics Data System (ADS)

Mathew, Manjusha Elizabeth; Ahmad, Ishak; Thomas, Sabu; Daik, Rusli; Kassim, Muhammad

2018-04-01

Poly vinyl benzyl chloride (PVBC) was synthesized by free radical polymerization of 4-vinyl benzyl chloride (VBC) using benzoyl peroxide initiator at 80°C. Amine functionalised polymer prepared by treatment of PVBC with trimethyl amine in different solvents such as water, ethanol, tetra hydro furan(THF) and dimethyl formamide(DMF). The polymers characterized structurally by nuclear magnetic resonance and infrared spectroscopic techniques. The thermal decomposition of the polymer is studied by Thermo Gravimetric Analysis(TGA) and found that the polymer has stability up to 230°C. The nitrogen content of the aminated polymer determined by elemental analysis. The nitrogen content obtained from tetra hydro furan and dimethyl formamide solvents are 20.1% and 19.9% respectively.

Synthesis of novel ganglioside GM4 analogues containing N-deacetylated and lactamized sialic acid: probes for searching new ligand structures for human L-selectin.

PubMed

Otsubo, N; Ishida, H; Kiso, M

2001-01-15

Novel ganglioside GM4 analogues, which contain N-deacetylated or lactamized sialic acid instead of usual N-acetylneuraminic acid, were synthesized in a highly efficient manner. (Methyl 4,7,8,9-tetra-O-acetyl-3,5-dideoxy-5-trifluoroacetamido-D-glycero-alpha-D-galacto-2-nonulopyranosylonate)-(2-->3)-4,6-di-O-acetyl-2-O-benzoyl-D-galactopyranosyl trichloroacetimidate was coupled with 2-(tetradecyl)hexadecanol to give the desired beta-glycoside in high yield. Successive O- and N-deacylation, and saponification of the methyl ester group afforded the N-deacetylated sialyl derivative that was converted by treatment with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in Me2SO into the lactamized sialic acid-containing ganglioside GM4 analogue.

Hydrolysis of mixed monomolecular films of triglyceride/lecithin by pancreatic lipase.

PubMed

Pieroni, G; Verger, R

1979-10-25

The main purpose of this study was to describe the influence of lecithin upon lipolysis of mixed monomolecular films of trioctanoylglycerol/didodecanoylphosphatidycholine by pancreatic lipase in order to mimic some physiological situations. The quantity of enzyme adsorbed to the interface was simultaneously determined using 5-thio-2-nitro[14C]benzoyl lipase. Lipolytic activity was enhanced 3- to 4-fold in the presence of colipase, an effect which is attributed to increased enzyme turnover number. When a pure triglyceride film was progressively diluted with lecithin, the minimum specific activity of lipase exhibited a bell-shaped curve: a mixed film containing only 20% trioctanoylglycerol was hydrolyzed at the same rate as a monolayer of pure triglyceride.

Preparation of poly(vinyl alcohol)/kaolinite nanocomposites via in situ polymerization

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

Jia Xin; Department of Chemistry, Hexi University, Zhangye 734000; Li Yanfeng

2008-03-04

Poly(vinyl alcohol)/kaolinite intercalated nanocomposites (Kao-PVA) were prepared via in situ intercalation radical polymerization. Vinyl acetate (VAc) was intercalated into kaolinite by a displacement method using dimethyl sulfoxide/kaolinite (Kao-DMSO) as the intermediate. Then, PVAc/kaolinite (Kao-PVAc) was obtained via radical polymerization with benzoyl peroxide (BPO) as initiator. Last, PVAc/kaolinite was saponified via direct-hydrolysis with NaOH solution in order to obtain PVA/kaolinite nanocomposites, which was characterized by Fourier-Transformation spectroscopy (FTIR), wide X-ray diffraction (WXRD) and transmission electron microscopy (TEM). Their differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results of the obtained PVA/kaolinite suggested that the thermal properties had an obvious improvement.

Approaches to α-amino acids via rearrangement to electron-deficient nitrogen: Beckmann and Hofmann rearrangements of appropriate carboxyl-protected substrates

PubMed Central

Rao, V Mohana

2012-01-01

Summary The titled approaches were effected with various 2-substituted benzoylacetic acid oximes 3 (Beckmann) and 2-substituted malonamic acids 9 (Hofmann), their carboxyl groups being masked as a 2,4,10-trioxaadamantane unit (an orthoacetate). The oxime mesylates have been rearranged with basic Al2O3 in refluxing CHCl3, and the malonamic acids with phenyliodoso acetate and KOH/MeOH. Both routes are characterized by excellent overall yields. Structure confirmation of final products was conducted with X-ray diffraction in selected cases. The final N-benzoyl and N-(methoxycarbonyl) products are α-amino acids with both carboxyl and amino protection; hence, they are of great interest in peptide synthesis. PMID:23019476

METHOD AND MEANS FOR RADIATION DOSIMETRY

DOEpatents

Shulte, J.W.; Suttle, J.F.

1958-02-18

This patent relates to a method and device for determining quantities of gamma radiation and x radiation by exposing to such radiation a mature of a purified halogenated hydrocarbon chosen from the class consisting of chloroform, bromoform, tetrachloroethane and 1,1,2trichloroethane, and a minor quantity of a sensitizer chosen from the class consisting of oxygen, benzoyl peroxide, sodium peroxide, and nitrobenzene, the proportion of the sensitizer being at least about 10/sup -5/ moles per cubic centimeter of halogenated hydrocarbon, the total amount of sensitizer depending upon the range of radiation to be measured, and chemically measuring the amount of decomposition generated by the irradiation of the sensitized halogenated hydrocarbon.

Novel polyimide compositions based on 4,4': Isophthaloyldiphthalic anaydride (IDPA)

NASA Technical Reports Server (NTRS)

Pratt, J. Richard (Inventor); Saintclair, Terry L. (Inventor)

1989-01-01

A series of twelve high temperature, high performance polyimide compositions based on 4,4'-isophthaloyl diphthalic anhydride (IDPA) was prepared and characterized. Tough, film-forming, organic solvent-insoluble polyimides were obtained. Three materials were semicrystalline. Several gave excellent long-term thermooxidative stability by isothermal thermogravimetric analysis (ITGA) at 300 C and 350 C in air when compared to Kapton H film (duPont). One extensively studied material displayed different levels of semicrystallinity over a wide range of final cure time/temperatures. The polyimide from IDPA and 1,3-bis (4-aminophenoxy 4'-benzoyl) benzene exhibited multiple crystallization and melting behavior, implying the existence of two kinetic and two thermodynamic crystallization and melting transitions by differential scanning calorimetry (DSC).

[Lavoisier and radicals].

PubMed

Lafont, Olivier

2007-01-01

Lavoisier and his co-workers (Guyton de Morveau, Bertholet, Fourcroy) considered that acids were constituted of oxygen and of something else that they called radicals. These radicals were known in some cases, i.e. nitrogen for nitrous acid, carbon for carbonic acid, phosphorus for phosphoric acid. In the case of sulfur, the sulfuric radical could be associated with different quantities of oxigen leading to sulfuric or sulfurous acids. In other cases radicals remained unknown at the time i.e. muriatic radical for muriatic acid, or benzoyl radical for benzoic acid. It is interesting to notice that Lavoisier evoked the case of compound radicals constituted of different substances such as carbon and hydrogen.

Inhibition of trypsin by condensed tannins and wine.

PubMed

Gonçalves, Rui; Soares, Susana; Mateus, Nuno; de Freitas, Victor

2007-09-05

Phenolic compounds are abundant vegetable secondary metabolites in the human diet. The ability of procyanidin oligomers and wine polyphenols to inhibit trypsin activity was studied using a versatile and reliable in vitro method. The hydrolysis of the chromogenic substrate N-benzoyl-d,l-arginine-p-nitroanilide (BApNA) by trypsin was followed by spectrophotometry in the presence and absence of condensed tannins and wine. A clear relationship between the degree of polymerization of procyanidins and enzymatic inhibition was observed. Trypsin activity inhibition was also detected in several types of wine. In general, the inhibition increased with the concentration of phenolic compounds in wines. These results may be relevant when considering these compounds as antinutritional factors, thereby contributing to a reduced absorption of nutrients.

The discovery of 1,2,3,9b-tetrahydro-5H-imidazo[2,1-a]isoindol-5-ones as a new class of respiratory syncytial virus (RSV) fusion inhibitors. Part 1.

PubMed

Bond, Silas; Draffan, Alistair G; Fenner, Jennifer E; Lambert, John; Lim, Chin Yu; Lin, Bo; Luttick, Angela; Mitchell, Jeffrey P; Morton, Craig J; Nearn, Roland H; Sanford, Vanessa; Stanislawski, Pauline C; Tucker, Simon P

2015-02-15

Respiratory syncytial virus (RSV) is a major cause of respiratory tract infections in infants, young children and adults. Compound 1a (9b-(4-chlorophenyl)-1-(4-fluorobenzoyl)-1,2,3,9b-tetrahydro-5H-imidazo[2,1-a]isoindol-5-one) was identified as an inhibitor of A and B strains of RSV targeting the fusion glycoprotein. SAR was developed by systematic exploration of the phenyl (R(1)) and benzoyl (R(2)) groups. Furthermore, introduction of a nitrogen at the 8-position of the tricyclic core resulted in active analogues with improved properties (aqueous solubility, protein binding and logD) and excellent rat pharmacokinetics (e.g., rat oral bioavailability of 89% for compound 17). Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthesis of 3-aminopropyl glycosides of linear β-(1 → 3)-D-glucooligosaccharides.

PubMed

Yashunsky, Dmitry V; Tsvetkov, Yury E; Grachev, Alexey A; Chizhov, Alexander O; Nifantiev, Nikolay E

2016-01-01

3-Aminopropyl glycosides of a series of linear β-(1 → 3)-linked D-glucooligosaccharides containing from 3 to 13 monosaccharide units were efficiently prepared. The synthetic scheme featured highly regioselective glycosylation of 4,6-O-benzylidene-protected 2,3-diol glycosyl acceptors with a disaccharide thioglycoside donor bearing chloroacetyl groups at O-2' and -3' as a temporary protection of the diol system. Iteration of the deprotection and glycosylation steps afforded the series of the title oligoglucosides differing in length by two monosaccharide units. A novel procedure for selective removal of acetyl groups in the presence of benzoyl ones consisting in a brief treatment with a large excess of hydrazine hydrate has been proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electronic excitation energies, three-state intersections, and photodissociation mechanisms of benzaldehyde and acetophenone

NASA Astrophysics Data System (ADS)

Cui, Ganglong; Lu, You; Thiel, Walter

2012-06-01

We report a theoretical study on the electronically excited states and the mechanisms of photodissociation of C6H5CHO and C6H5COCH3. For both molecules, we find an S1/T2/T1 three-state intersection region, which allows for an efficient S1 → T1 intersystem crossing via the T2 state that acts as a relay. Consequently, T1 reactions become the major radical photodissociation channels. According to the computed energy profiles, T1 photodissociation mainly yields phenyl and formyl radicals in the case of benzaldehyde, and benzoyl and methyl radicals in the case of acetophenone, with different C-C bonds being cleaved preferentially. The computational results agree well with the available experimental data.

High temperature concrete composites containing organosiloxane crosslinked copolymers

DOEpatents

Zeldin, Arkady; Carciello, Neal; Kukacka, Lawrence; Fontana, Jack

1980-01-01

This invention relates to high temperature polymer concrete composites comprising about 10-30% by weight of a liquid monomer mixture consisting essentially of an organosiloxane polymer crosslinked with an olefinically unsaturated monomer selected from the group consisting of styrene, methyl methacrylate, trimethylolpropane trimethacrylate, triallyl cyanurate, n-phenylmalimide, divinyl benzene and mixtures theroef; and about 70-90% by weight of an inert inorganic filler system containing silica sand and preferably a member selected from the group consisting of portland cement, Fe.sub.2 O.sub.3, carbon black and mixtures thereof; and optionally a free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide and other organic peroxides to initiate crosspolymerization of the monomer mixture in the presence of the inorganic filler.

Reactions of bis(2,2,3,3-tetrafluoropropyl) phosphorisocyanatidite and tris(2,2,3,3-tetrafluoropropyl) phosphite with carbonyl compounds

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

Konovalova, I.V.; Burnaeva, L.A.; Khusnutdinova, E.K.

1986-11-20

The authors studied the reactions of bis(2,2,3,3-tetrafluoropropyl) phosphorisocyanatidite with carbonyl and ..cap alpha..-halo carbonyl compounds, namely, benzil, ethyl phenylglyoxylate, methyl chloropyruvate, and diethyl (trichloroacetyl)phosphonate. The reaction of bis(2,2,3,3-tetrachloropropyl) phosphorisocyanatidite with benzil required severe conditions (3 h at 40/sup 0/C). The /sup 31/P NMR spectrum of the reaction mixture contains two signals at 12 and -55 ppm, which probably belong to the azaphospholine and its dimer. By vacuum fractionation they isolated a thick liquid, the /sup 31/P NMR spectrum of which contains a signal 12 ppm corresponding to 5-benzoyl-4-oxo-5-phenyl-2,2-bis(2,2,3,3-tetrafluoropropoxy)-..delta../sup 2/-1,3,2lambda/sup 5/-oxazaphospholine.

[Complex formation between alpha-chymotrypsin and block copolymers based on ethylene and propylene oxide, induced by high pressure].

PubMed

Topchieva, I N; Sorokina, E M; Kurganov, B I; Zhulin, V M; Makarova, Z G

1996-06-01

A new method of formation of non-covalent adducts based on an amphiphilic diblock copolymer of ethylene and propylene oxides with molecular mass of 2 kDa and alpha-chymotrypsin (ChT) under high pressure, has been developed. The composition of the complexes corresponds to seven polymer molecules per one ChT molecule in the pressure range of 1.1 to 400 MPa. The complexes fully retain the catalytic activity. Kinetic constants (Km and kcat) for enzymatic hydrolysis of N-benzoyl-L-tyrosine ethyl ester catalyzed by the complexes are identical with the corresponding values for native ChT. Analysis of kinetics of thermal inactivation of the complexes revealed that the constant of the rate of the slow inactivation step is markedly lower than for ChT.

Alternative bleaching methods for Cheddar cheese whey.

PubMed

Kang, E J; Smith, T J; Drake, M A

2012-07-01

Residual annatto colorant (norbixin) in fluid Cheddar cheese whey can be bleached. The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact the flavor of dried whey protein. The objective of this study was to evaluate alternative methods for bleaching liquid whey: ultraviolet radiation (UV), acid-activated bentonite (BT), and ozone (OZ). Colored Cheddar cheese whey was manufactured followed by pasteurization and fat separation. Liquid whey was subjected to one of 5 treatments: control (CT) (no bleaching; 50 °C, 1 h), HP (250 mg/kg; 50 °C, 1 h), UV (1 min exposure; 50 °C), BT (0.5% w/w; 50 °C, 1 h), or OZ (2.2g/h, 50 °C, 1 h). The treated whey was then ultrafiltered, diafiltered, and spray-dried to 80% whey protein concentrate (WPC80). The entire experiment was replicated 3 times. Color (norbixin extraction and measurement), descriptive sensory, and instrumental volatile analyses were conducted on WPC80. Norbixin elimination was 28%, 79%, 39%, and 15% for HP, BT, UV, and OZ treatments, respectively. WPC80 from bleached whey, regardless of bleaching agent, had lower sweet aromatic and cooked/milky flavors compared to unbleached CT (P < 0.05). The HP and BT WPC80 had higher fatty flavor compared to the CT WPC80 (P < 0.05), and the UV and OZ WPC80 had distinct mushroom/burnt and animal flavors. Volatile compound results were consistent with sensory results and confirmed higher relative abundances of volatile aldehydes in UV, HP, and OZ WPC80 compared to CT and BT WPC80. Based on bleaching efficacy and flavor, BT may be an alternative to chemical bleaching of fluid whey. The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact flavor of dried whey protein, and restrictions on these agents are increasing. This study evaluated 3 alternatives to chemical bleaching of fluid whey: UV radiation, ozone, and bentonite. © 2012 Institute of Food

Short communication: The influence of solids concentration and bleaching agent on bleaching efficacy and flavor of sweet whey powder.

PubMed

Jervis, M G; Smith, T J; Drake, M A

2015-04-01

Recent studies have demonstrated the effect of bleaching conditions and bleaching agent on flavor and functional properties of whey protein ingredients. Solids concentration at bleaching significantly affected bleaching efficacy and flavor effects of different bleaching agents. It is not known if these parameters influence quality of sweet whey powder (SWP). The purpose of this study was to determine the effects of solids concentration and bleaching agent on the flavor and bleaching efficacy of SWP. Colored cheddar whey was manufactured, fat separated, and pasteurized. Subsequently, the whey (6.7% solids) was bleached, concentrated using reverse osmosis (RO) to 14% solids, and then spray dried, or whey was concentrated before bleaching and then spray dried. Bleaching treatments included a control (no bleaching, 50 °C, 60 min), hydrogen peroxide (HP; 250 mg/kg, 50 °C, 60 min), benzoyl peroxide (50 mg/kg, 50 °C, 60 min), lactoperoxidase (20 mg/kg of HP, 50 °C, 30 min), and external peroxidase (MaxiBright, DSM Food Specialties, Delft, the Netherlands; 2 dairy bleaching units/mL, 50 °C, 30 min). The experiment was repeated in triplicate. Sensory properties and volatile compounds of SWP were evaluated by a trained panel and gas chromatography-mass spectrometry, respectively. Bleaching efficacy (norbixin destruction) and benzoic acid were measured by HPLC. Differences in bleaching efficacy, sensory and volatile compound profiles, and benzoic acid were observed with different bleaching agents, consistent with previous studies. Solids concentration affected bleaching efficacy of HP, but not other bleaching agents. The SWP from whey bleached with HP or lactoperoxidase following RO had increased cardboard and fatty flavors and higher concentrations of lipid oxidation compounds compared with SWP from whey bleached before RO. The SWP bleached with benzoyl peroxide after RO contained less benzoic acid than SWP from whey bleached before RO. These results indicate that

Functional expression of P2X4 receptor in capillary endothelial cells of the cochlear spiral ligament and its role in regulating the capillary diameter.

PubMed

Wu, T; Dai, M; Shi, X R; Jiang, Z G; Nuttall, A L

2011-07-01

The cochlear lateral wall generates the endocochlear potential (EP), which creates a driving force for the hair cell transduction current and is essential for normal hearing. Blood flow at the cochlear lateral wall is critically important for maintaining the EP. The vulnerability of the EP to hypoxia suggests that the blood flow in the cochlear lateral wall is dynamically and precisely regulated to meet the changing metabolic needs of the cochlear lateral wall. It has been reported that ATP, an important extracellular signaling molecule, plays an essential role in regulating cochlear blood flow. However, the cellular mechanism underlying ATP-induced regional blood flow changes has not been investigated. In the current study, we demonstrate that 1) the P2X4 receptor is expressed in endothelial cells (ECs) of spiral ligament (SL) capillaries. 2) ATP elicits a characteristic current through P2X4 on ECs in a dose-dependent manner (EC(50) = 0.16 mM). The ATP current has a reversal potential at ∼0 mV; is inhibited by 5-(3-bromophenyl)-1,3-dihydro-2H-benzofuro[3,2-e]-1,4-diazepin-2-one (5-BDBD), LaCl(3), pyridoxal phosphate-6-azo(benzene-2,4-disulfonic acid) tetrasodium salt hydrate (PPADS), and extracellular acidosis; and is less sensitive to α,β-methyleneadenosine 5'-triphosphate (α,β-MeATP) and 2'- and 3'-O-(4-benzoyl-benzoyl) adenosine 5'-triphosphate (BzATP). 3) ATP elicits a transient increase of intracellular Ca(2+) in ECs. 4) In accordance with the above in vitro findings, perilymphatic ATP (1 mM) caused dilation in SL capillaries in vivo by 11.5%. N(ω)-nitro-l-arginine methyl ester hydrochloride (l-NAME), a nonselective inhibitor of nitric oxide synthase, or 5-BDBD, the specific P2X4 inhibitor, significantly blocked the dilation. These findings support our hypothesis that extracellular ATP regulates cochlear lateral blood flow through P2X4 activation in ECs.

Purinergic regulation of cholangiocyte secretion: identification of a novel role for P2X receptors.

PubMed

Doctor, R Brian; Matzakos, Thomas; McWilliams, Ryan; Johnson, Sylene; Feranchak, Andrew P; Fitz, J Gregory

2005-04-01

The P2X family of ligand-gated cation channels is comprised of seven distinct isoforms activated by binding of extracellular purines. Although originally identified in neurons, there is increasing evidence for expression of P2X receptors in epithelia as well. Because ATP is released by both hepatocytes and cholangiocytes, these studies were performed to evaluate whether P2X receptors are present in cholangiocytes and contribute to local regulation of biliary secretion and bile formation. RT-PCR of cDNA from cultured normal rat cholangiocytes detected transcripts for P2X receptors 2, 3, 4, and 6; products from P2X3 and P2X4 were robust and always detectable. In cholangiocyte lysates, P2X4 protein was readily detected, and immunohistochemical staining of intact rat liver revealed P2X4 protein concentrated in intrahepatic bile ducts. To assess the functional significance of P2X4, isolated Mz-ChA-1 cells were exposed to the P2X4-preferring agonist 2',3'-O-(4-benzoyl-benzoyl)-ATP (BzATP), which activated inward currents of -18.2 + 3.0 pA/pF. In cholangiocyte monolayers, BzATP but not P2X3 agonists elicited robust Cl(-) secretory responses (short-circuit current) when applied to either the apical (DeltaI(sc) 22.1 +/- 3.3 microA) or basolateral (18.5 +/- 1.6 microA) chamber, with half-maximal stimulation at approximately 10 microM and approximately 1 microM, respectively. The response to BzATP was unaffected by suramin (not significant) and was inhibited by Cu(2+) (P < 0.01). These studies provide molecular and biochemical evidence for the presence of P2X receptors in cholangiocytes. Functional studies indicate that P2X4 is likely the primary isoform involved, representing a novel and functionally important component of the purinergic signaling complex modulating biliary secretion.

Nucleoside Reverse Transcriptase Inhibitors Suppress Laser-Induced Choroidal Neovascularization in Mice

PubMed Central

Mizutani, Takeshi; Fowler, Benjamin J.; Kim, Younghee; Yasuma, Reo; Krueger, Laura A.; Gelfand, Bradley D.; Ambati, Jayakrishna

2015-01-01

Purpose To evaluate the efficacy of nucleoside reverse transcriptase inhibitors (NRTIs) in the laser-induced mouse model of choroidal neovascularization (CNV). Methods We evaluated the NRTIs lamivudine (3TC), zidovudine (AZT), and abacavir (ABC) and the P2X7 antagonist A438079. Choroidal neovascularization was induced by laser injury in C57BL/6J wild-type, Nlrp3−/−, and P2rx7−/− mice, and CNV volume was measured after 7 days by confocal microscopy. Drugs were administered by intravitreous injection immediately after the laser injury. Vascular endothelial growth factor-A in RPE-choroid lysates was measured 3 days after laser injury by ELISA. HEK293 cells expressing human and mouse P2X7 were exposed to the selective P2X7 receptor agonist 2′, 3′-(benzoyl-4-benzoyl)-ATP (Bz-ATP) with or without 3TC, and VEGF-A levels in media were measured by ELISA. Results Intravitreous injection of 3TC, AZT, and ABC significantly suppressed laser-induced CNV in C57BL/6J wild-type and Nlrp3−/− mice (P < 0.05) but not in P2rx7−/− mice. Intravitreous injection of A438079 also suppressed the laser-induced CNV (P < 0.05). The NRTIs 3TC, AZT, and ABC blocked VEGF-A levels in the RPE/choroid after laser injury in wild-type (P < 0.05) but not P2rx7−/− mice. Moreover, there was no additive effect of 3TC on CNV inhibition when coadministered with a neutralizing VEGF-A antibody. Stimulation of human and mouse P2X7-expressing HEK293 cells with Bz-ATP increased VEGF secretion (P < 0.001), which was abrogated by 3TC (P < 0.001). Stimulation of primary human RPE cells with Bz-ATP increased VEGFA and IL6 mRNA levels, which were abrogated by 3TC. Conclusions Multiple clinically relevant NRTIs suppressed laser-induced CNV and downregulated VEGF-A, via P2X7. PMID:26529046

Scopadulciol, an inhibitor of gastric H+, K(+)-ATPase from Scoparia dulcis, and its structure-activity relationships.

PubMed

Hayashi, T; Asano, S; Mizutani, M; Takeguchi, N; Kojima, T; Okamura, K; Morita, N

1991-01-01

A new tetracyclic diterpenoid, scopadulciol [3], together with 6-methoxybenzoxazolinone, glutinol, and acacetin, was isolated from the 70% EtOH extract of Scoparia dulcis collected in Taiwan. Its structure was elucidated to be 6 beta-benzoyl-12-methyl-13-oxo-9(12)a,9(12)b-dihomo-18-podocarpanol on the basis of spectral data. It mildly inhibited hog gastric H+, K(+)-ATPase. Examination of the inhibitory activities of derivatives of scopadulcic acid B [2], including 3, revealed that methylation of the carboxyl group and introduction of an acetyl group or oxime at C-13 or C-18 markedly enhanced the inhibitory activity, while debenzoylation reduced the activity. Among the 30 compounds tested, compound 12, a methyl ester of scopadulcic acid B [2], showed the most potent activity.

Novel dimer based descriptors with solvational computation for QSAR study of oxadiazoylbenzoyl-ureas as novel insect-growth regulators.

PubMed

Fan, Feng; Cheng, Jiagao; Li, Zhong; Xu, Xiaoyong; Qian, Xuhong

2010-02-01

Molecular aggregation state of bioactive compounds plays a key role in its bio-interactive procedure. In this article, based on the structure information of dimers, the simplest model of molecular aggregation state, and combined with solvational computation, total four descriptors (DeltaV, MR2, DeltaE(1), and DeltaE(2)) were calculated for QSAR study of a novel insect-growth regulator, N-(5-phenyl-1,3,4-oxadiazol-2-yl)-N'-benzoyl urea. Two QSAR models were constructed with r(2) = 0.671, q(2) = 0.516 and r(2) = 0.816, q(2) = 0.695, respectively. It implicates that the bioactivity may strongly depend on the characters of molecular aggregation state, especially on the dimeric transport ability from oil phase to water phase. Copyright 2009 Wiley Periodicals, Inc.

Synthesis, characterization and antibacterial study of tripodal tris-(N-benzoylthioureido)ethylamine

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

Adan, Dalina; Yamin, Bohari; Leng, Ong Wei

A new tripodal tris-(N-benzoylthiouredoethyl)amine has been successfully synthesized and characterized by spectroscopic technique such as FTIR, ESI MS, {sup 1}H and {sup 13}C NMR. The microanalysis data is in a good agreement with the expected molecular formula. The {sup 1}H NMR chemical shift for both amide and thioamide proton are at lower field than their normal value indicates the presence of the hydrogen bond between the carbonyl oxygen atom and thioamide hydrogen. This is possible when the benzoyl group adopt a trans configuration againts thione group along the C-N bond. The compound has been tested for antibacterial activity against threemore » selected bacteria namely Staphylococcus aureus, Proteus vulgaris and Pseudomanas aeroginosa but there is no significant activities observed.« less

Phosphorescence white organic light-emitting diodes with single emitting layer based on isoquinolinefluorene-carbazole containing host.

PubMed

Koo, Ja Ryong; Lee, Seok Jae; Hyung, Gun Woo; Kim, Bo Young; Shin, Hyun Su; Lee, Kum Hee; Yoon, Seung Soo; Kim, Woo Young; Kim, Young Kwan

2013-03-01

We have demonstrated a stable phosphorescent white organic light-emitting diodes (WOLEDs) using an orange emitter, Bis(5-benzoyl-2-(4-fluorophenyl)pyridinato-C,N) iridium(III)acetylacetonate [(Bz4Fppy)2Ir(III)acac] doped into a newly synthesized blue host material, 2-(carbazol-9-yl)-7-(isoquinolin-1-yl)-9,9-diethylfluorene (CzFliq). When 1 wt.% (Bz4Fppy)2Ir(III)acac was doped into emitting layer, it was realized an improved EL performance and a pure white color in the OLED. The optimum WOLED showed maximum values as a luminous efficiency of 10.14 cd/A, a power efficiency of 10.24 Im/W, a peak external quantum efficiency 4.07%, and Commission Internationale de L'Eclairage coordinates of (0.34, 0.39) at 8 V.

Natural Abenquines and Their Synthetic Analogues Exert Algicidal Activity against Bloom-Forming Cyanobacteria.

PubMed

Nain-Perez, Amalyn; Barbosa, Luiz Cláudio Almeida; Maltha, Célia Regina Álvares; Forlani, Giuseppe

2017-04-28

Abenquines are natural quinones, produced by some Streptomycetes, showing the ability to inhibit cyanobacterial growth in the 1 to 100 μM range. To further elucidate their biological significance, the synthesis of several analogues (4f-h, 5a-h) allowed us to identify some steric and electronic requirements for bioactivity. Replacing the acetyl by a benzoyl group in the quinone core and also changing the amino acid moiety with ethylpyrimidinyl or ethylpyrrolidinyl groups resulted in analogues 25-fold more potent than the natural abenquines. The two most effective analogues inhibited the proliferation of five cyanobacterial strains tested, with IC 50 values ranging from 0.3 to 3 μM. These compounds may be useful leads for the development of an effective strategy for the control of cyanobacterial blooms.

Covalent chromatography. Preparation of fully active papain from dried papaya latex

PubMed Central

Brocklehurst, Keith; Carlsson, Jan; Kierstan, Marek P. J.; Crook, Eric M.

1973-01-01

1. A Sepharose–(glutathione–2-pyridyl disulphide) conjugate has been prepared. 2. Its use in a new type of chromatography, covalent chromatography by thiol–disulphide interchange, is described. 3. With this technique, papain containing 1 intact catalytic site [thiol with high reactivity towards 2,2′-dipyridyl disulphide (2-Py-S-S-2-Py) at pH4] per mol of protein is readily prepared both from dried papaya latex and from commercial 2×crystallized partially active papain. 4. The catalysis of the hydrolysis of α-N-benzoyl-l-arginine ethyl ester at pH6.0, 25.0°C, I=0.3 by fully active papain thus prepared is characterized by Km=18.2±<0.1mm and kcat.=16.4±0.5s−1. PMID:4733241

A practical approach for the use of oral isotretinoin for infantile acne.

PubMed

Barnes, Cheryl J; Eichenfield, Lawrence F; Lee, Jungho; Cunningham, Bari B

2005-01-01

Infantile acne is a rare occurrence. It is more common in boys and predominately occurs on the cheeks in infants between the ages of 1 and 16 months. Clinically, the lesions range from comedones to inflammatory papulopustules to cysts. Successful therapies include topical tretinoin, benzoyl peroxide and topical and oral erythromycin. For more serious cases, oral isotretinoin (Accutane) has been reported to successfully treat recalcitrant infantile cystic acne. We describe two additional patients with infantile cystic acne treated successfully with oral isotretinoin. The dose of isotretinoin used ranged from 0.2 mg/kg/day to 1.5 mg/kg/day. The treatment duration varied from 5 to 14 months. Careful monthly monitoring is recommended because of the many side effects reported with isotretinoin. Practical tips for the administration of oral isotretinoin in infants are reviewed.

High temperature chemically resistant polymer concrete

DOEpatents

Sugama, T.; Kukacka, L.E.

High temperature chemically resistant, non-aqueous polymer concrete composites consist of about 12 to 20% by weight of a water-insoluble polymer binder. The binder is polymerized in situ from a liquid vinyl-type monomer or mixture of vinyl containing monomers such as triallylcyanurate, styrene, acrylonitrile, acrylamide, methacrylamide, methyl-methacrylate, trimethylolpropane trimethacrylate and divinyl benzene. About 5 to 40% by weight of a reactive inorganic filler selected from the group consisting of tricalcium silicate and dicalcium silicate and mixtures containing less than 2% free lime, and about 48 to 83% by weight of silica sand/ and a free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, other orgaic peroxides and combinations to initiate polymerization of the monomer in the presence of the inorganic filers are used.

Radical Initiated Hydrosilylation on Silicon Nanocrystal Surfaces: An Evaluation of Functional Group Tolerance and Mechanistic Study.

PubMed

Yang, Zhenyu; Gonzalez, Christina M; Purkait, Tapas K; Iqbal, Muhammad; Meldrum, Al; Veinot, Jonathan G C

2015-09-29

Hydrosilylation is among the most common methods used for modifying silicon surface chemistry. It provides a wide range of surface functionalities and effective passivation of surface sites. Herein, we report a systematic study of radical initiated hydrosilylation of silicon nanocrystal (SiNC) surfaces using two common radical initiators (i.e., 2,2'-azobis(2-methylpropionitrile) and benzoyl peroxide). Compared to other widely applied hydrosilylation methods (e.g., thermal, photochemical, and catalytic), the radical initiator based approach is particle size independent, requires comparatively low reaction temperatures, and yields monolayer surface passivation after short reaction times. The effects of differing functional groups (i.e., alkene, alkyne, carboxylic acid, and ester) on the radical initiated hydrosilylation are also explored. The results indicate functionalization occurs and results in the formation of monolayer passivated surfaces.

An enzyme-linked immunosorbent assay for monoester-type aconitic alkaloids and its application in the pharmacokinetic study of benzoylhypaconine in rats.

PubMed

Liu, Can-Can; Xu, Yun-Hui; Yuan, Shuai; Xu, Yu; Hua, Mo-Li

2018-04-01

A new enzyme-linked immunosorbent assay (ELISA) method for quantitative determination of monoester-type aconitic alkaloids was developed. The antibodies derived from the immunogen of benzoylmesaconine (BM) could be electively affined to benzoylaconitine-type alkaloids with an ester bond (14-benzoyl-), especially to benzoylhypaconine (BH, 140.02% of cross-reactivity). The effective working range of BH was 1 ng/ml to 5 μg/ml; the lower limit of detection and the quantification were 0.35 and 0.97 ng/ml, respectively. The values of CV for intra-day and inter-day assays and recovery ratios were in acceptable ranges. The results of stability experiments were also satisfactory. This validated method was employed for pharmacokinetic study of BH in rats and the bioavailability orally administered was estimated to be 16.3%.

Synthesis and Anti-cancer Activity of 3-substituted Benzoyl-4-substituted Phenyl-1H-pyrrole Derivatives.

PubMed

Zhan, Xiaoping; Qin, Weixi; Wang, Shuai; Zhao, Kai; Xin, Yuxuan; Wang, Yaolin; Qi, Qi; Mao, Zhenmin

2017-01-01

Cancer is considered a major public health problem worldwide. The aim of this paper is to design and synthesis of novel anticancer agents with potent anticancer activity and minimum side effects. A series of pyrrole derivatives were synthesized, their anti-cancer activity against nine cancer cell lines and two non-cancer cell lines were evaluated by MTT assay, and their cell cycle progression were determined by flow cytometry analysis. The study of the structure-activity relationships revealed that the introduction of the electron-donation groups at the 4th position of the pyrrole ring increased the anti-cancer activity. Among the synthesized compounds, specially the compounds bearing 3,4-dimethoxy phenyl at the 4th position of the pyrrole ring showed potent anti-cancer activity, cpd 19 was the most potent against MGC 80-3, HCT-116 and CHO cell lines (IC50s = 1.0－1.7 μM), cpd 21 was the most potent against HepG2, DU145 and CT-26 cell lines (IC50s = 0.5－0.9 μM), and cpd 15 was the most potent against A549 (IC50 = 3.6 μM). Moreover, these potent compounds showed weak cytotoxicity against HUVEC and NIH/3T3. Thus, the cpds 15, 19 and 21 show potential anti-cancer for further investigation. Furthermore, the flow cytometry analysis revealed that cpd 21 arrested the CT-26 cells at S phase, and induced the cell apoptosis. Thus, these compounds with the potent anticancer activity and low toxicity have potential for the development of new anticancer chemotherapy agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A new spermidine macrocyclic alkaloid isolated from Gymnosporia arenicola leaf.

PubMed

da Silva, Gustavo; Martinho, Ana; Soengas, Raquel González; Duarte, Ana Paula; Serrano, Rita; Gomes, Elsa Teixeira; Silva, Olga

2015-10-01

The isolation and structural elucidation of a macrocyclic alkaloid, characterized by the presence of a 13-membered macrolactam ring containing a spermidine unit N-linked to a benzoyl group is hereby reported. The structure of this previously unknown spermidine alkaloid isolated from Gymnosporia arenicola (Celastraceae) leaves has been elucidated by (1)H and (13)C NMR spectroscopy (including bidimensional analysis) and further characterized by high-resolution mass spectrometry and polarimetry. A route for the biosynthesis of this new bioactive macrocycle is proposed and the cytotoxicity of the compound was evaluated against two ATCC cell lines - one normal-derived (MCF10A) and one cancer-derived cell line (MCF7) - using the MTT assay. The alkaloid revealed to be non-cytotoxic against both cell lines. The IC50 values from the cells were also determined. Copyright © 2015 Elsevier B.V. All rights reserved.

Genetically encoded photochemical covalent crosslinking within the Hcp-1 self-assembling bacterial secretion machinery.

PubMed

Antonczak, Alicja K; Milholland, Kedric; Tippmann, Eric M

2018-05-01

The target protein, Hcp1, was first described as part of the bacterial Type VI secretion system from Pseudomonas aeruginosa. The protein first self-assembles into a hexamer and then the hexamers further stack into a nanotubular structure. Hcp1 monomers were targeted for mutagenesis with two widely used photoactivatable amino acids: para-benzoyl phenylalanine or para-azidophenylalanine. The ability of these amino acids to form covalent adducts within the Hcp1 self-assembled system was investigated. Multiple residues, putatively of equal distance between the monomer-monomer interface were targeted. The efficiency of each amino acid to covalently link self-assembled hexamers was determined. The results demonstrate the choice and role of genetically encoded tools applied to complicated biological processes such as self-assembly and also suggested some structural dynamics of the Hcp-1 protein not obvious from crystallographic structures.

Initiation of Anaerobic Degradation of p-Cresol by Formation of 4-Hydroxybenzylsuccinate in Desulfobacterium cetonicum

PubMed Central

Müller, Jochen A.; Galushko, Alexander S.; Kappler, Andreas; Schink, Bernhard

2001-01-01

The anaerobic bacterium Desulfobacterium cetonicum oxidized p-cresol completely to CO2 with sulfate as the electron acceptor. During growth, 4-hydroxybenzylsuccinate accumulated in the medium. This finding indicated that the methyl group of p-cresol is activated by addition to fumarate, analogous to anaerobic toluene, m-xylene, and m-cresol degradation. In cell extracts, the formation of 4-hydroxybenzylsuccinate from p-cresol and fumarate was detected at an initial rate of 0.57 nmol min−1 (mg of protein)−1. This activity was specific for extracts of p-cresol-grown cells. 4-Hydroxybenzylsuccinate was degraded further to 4-hydroxybenzoyl-coenzyme A (CoA), most likely via β-oxidation. 4-Hydroxybenzoyl-CoA was reductively dehydroxylated to benzoyl-CoA. There was no evidence of degradation of p-cresol via methyl group oxidation by p-cresol-methylhydroxylase in this bacterium. PMID:11133971

An update on the management of acne vulgaris

PubMed Central

Keri, Jonette; Shiman, Michael

2009-01-01

Acne vulgaris is a common skin disorder that can affect individuals from childhood to adulthood, most often occurring in the teenage years. Acne can have a significant physical, emotional, and social impact on an individual. Many different treatment options are available for the treatment of acne vulgaris. Commonly used topical treatments include benzoyl peroxide, antibiotics, sulfur and sodium sulfacetamide, azelaic acid, and retinoids. Systemic treatment is frequently used and includes the use of systemic antibiotics, oral contraceptives, antiandrogens, and retinoids. Other treatment modalities exist such as the use of superficial chemical peels as well as using laser and light devices for the treatment of acne. With the multitude of treatment options and the rapidly expanding newer technologies available to clinicians, it is important to review and be aware of the current literature and studies regarding the treatment of acne vulgaris. PMID:21436973

Mutagenicity of benzotrichloride and related compounds.

PubMed

Yasuo, K; Fujimoto, S; Katoh, M; Kikuchi, Y; Kada, T

1978-11-01

Benzotrichloride (BTC), benzal chloride (BDC), benzyl chloride (BC) and benzoyl chloride (BOC) were surveyed for their mutagenicity in microbial systems such as rec-assay using Bacillus subtilis and reversion assays using E. coli WP2 and Ames Salmonella TA strains with or without metabolic activation in vitro. BTC and BDC required metabolic activation for their mutagenic activities in several strains of E. coli and Salmonella. The mutagenic metabolites of these compounds may not have been produced by hydrolysis. BC was weakly mutagenic without metabolic activation. Only BOC exhibited no mutagenic activity in the detection procedures used. The mutagenic metabolite of BTC might be very unstable under our experimental conditions. The strain E. coli WP2 try hcr was more sensitive than E. coli B/r WP2 try (hcr+) with regard to the mutagenicity of BTC.

Synthesis of some purine and pyrimidine nucleosides of 3-amino-2,3,6-trideoxy-L-lyxo-hexopyranose (daunosamine).

PubMed

Lazzari, E; Vigevani, A; Arcamone, F

1977-06-01

The daunosaminyl analogue of the antibiotic puromycin and the nucleoside derivatives of daunosamine with adenine, thymine, and cytosine have been synthesised. The nucleoside derivatives of 6-dimethylaminopurine, thymine, and cytosine were prepared by melting the protected daunosamine with the protected base in vacuo. Daunosaminyladenine was obtained by condensing N-trifluoroacetyl-O-trifluoroacetyl-alpha-daunosaminyl chloride either with N6-benzoyl-9-chloromercuryadenine in boiling xylene or with N6-benzoyladenine in dichloromethane at room temperature in the presence of a molecular sieve. In each reaction, the beta-anomeric nucleoside was obtained, as shown by p.m.r. data. The protecting groups were removed with barium hydroxide or methanolic ammonia to give the free aminonucleosides in good yield. 9-beta-Daunosaminyl-6-dimethylaminopurine was coupled to N-benzylocyxcarbonyl-O-methyltyrosine, giving, after hydrogenolysis, the daunosaminyl analogue of puromycin.

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification.

PubMed

Zaghi, Anna; Ragno, Daniele; Di Carmine, Graziano; De Risi, Carmela; Bortolini, Olga; Giovannini, Pier Paolo; Fantin, Giancarlo; Massi, Alessandro

2016-01-01

A convenient heterogeneous continuous-flow procedure for the polarity reversal of aromatic α-diketones is presented. Propaedeutic batch experiments have been initially performed to select the optimal supported base capable to initiate the two electron-transfer process from the carbamoyl anion of the N , N -dimethylformamide (DMF) solvent to the α-diketone and generate the corresponding enediolate active species. After having identified the 2- tert -butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine on polystyrene (PS-BEMP) as the suitable base, packed-bed microreactors (pressure-resistant stainless-steel columns) have been fabricated and operated to accomplish the chemoselective synthesis of aroylated α-hydroxy ketones and 2-benzoyl-1,4-diones (benzoin- and Stetter-like products, respectively) with a good level of efficiency and with a long-term stability of the packing material (up to five days).

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

PubMed Central

Zaghi, Anna; Ragno, Daniele; Di Carmine, Graziano; De Risi, Carmela; Bortolini, Olga; Giovannini, Pier Paolo; Fantin, Giancarlo

2016-01-01

A convenient heterogeneous continuous-flow procedure for the polarity reversal of aromatic α-diketones is presented. Propaedeutic batch experiments have been initially performed to select the optimal supported base capable to initiate the two electron-transfer process from the carbamoyl anion of the N,N-dimethylformamide (DMF) solvent to the α-diketone and generate the corresponding enediolate active species. After having identified the 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine on polystyrene (PS-BEMP) as the suitable base, packed-bed microreactors (pressure-resistant stainless-steel columns) have been fabricated and operated to accomplish the chemoselective synthesis of aroylated α-hydroxy ketones and 2-benzoyl-1,4-diones (benzoin- and Stetter-like products, respectively) with a good level of efficiency and with a long-term stability of the packing material (up to five days). PMID:28144342

CIDEP study on the flash photolysis of benzoin included in β-cyclodextrin

NASA Astrophysics Data System (ADS)

Kitahama, Yasutaka; Murai, Hisao

1996-10-01

The photodissociation reaction of benzoin (Norrish type I) included in a β-cyclodextrin (CD) cavity in the aqueous phase was studied by using time-resolved ESR and Fourier transform ESR methods. The CIDEP (chemically induced dynamic electron polarization) spectra of α-hydroxybenzyl radical and benzoyl radical were carefully investigated in β-CD, in ethanol, in an ethanol/water mixture, and in saturated aqueous solutions. According to these data and the calculations due to an extended Bloch equation, the spin-lattice relaxation time observed in the β-CD system was compared to those in homogeneous solutions. It is concluded that dissociation takes place from the excited triplet state of benzoin and the fragment radicals are easily ejected from the cavity of β-CD to the aqueous phase much faster than the time-resolution (˜ 20 ns) of the present FT-ESR measurement.

Crystal structure of 4-meth-oxy-N-(piperidine-1-carbono-thio-yl)benzamide.

PubMed

Suhud, Khairi; Hasbullah, Siti Aishah; Ahmad, Musa; Heng, Lee Yook; Kassim, Mohammad B

2017-10-01

In the title compound, C 14 H 18 N 2 O 2 S, the piperidine ring has a chair conformation. Its mean plane is twisted with respect to the 4-meth-oxy-benzoyl ring, with a dihedral angle of 63.0 (3)°. The central N-C(=S)-N(H)-C(=O) bridge is twisted with an N-C-N-C torsion angle of 74.8 (6)°. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen bonds, forming chains along the c -axis direction. Adjacent chains are linked by C-H⋯π inter-actions, forming layers parallel to the ac plane. The layers are linked by offset π-π inter-actions [inter-centroid distance = 3.927 (3) Å], forming a supra-molecular three-dimensional structure.

Improved method for HPLC analysis of polyamines, agmatine and aromatic monoamines in plant tissue

NASA Technical Reports Server (NTRS)

Slocum, R. D.; Flores, H. E.; Galston, A. W.; Weinstein, L. H.

1989-01-01

The high performance liquid chromatographic (HPLC) method of Flores and Galston (1982 Plant Physiol 69: 701) for the separation and quantitation of benzoylated polyamines in plant tissues has been widely adopted by other workers. However, due to previously unrecognized problems associated with the derivatization of agmatine, this important intermediate in plant polyamine metabolism cannot be quantitated using this method. Also, two polyamines, putrescine and diaminopropane, also are not well resolved using this method. A simple modification of the original HPLC procedure greatly improves the separation and quantitation of these amines, and further allows the simulation analysis of phenethylamine and tyramine, which are major monoamine constituents of tobacco and other plant tissues. We have used this modified HPLC method to characterize amine titers in suspension cultured carrot (Daucas carota L.) cells and tobacco (Nicotiana tabacum L.) leaf tissues.

3-methyl-2-phenyl-1-substituted-indole derivatives as indomethacin analogs: design, synthesis and biological evaluation as potential anti-inflammatory and analgesic agents.

PubMed

Abdellatif, Khaled R A; Lamie, Phoebe F; Omar, Hany A

2016-01-01

In a new group of 3-methyl-2-phenyl-1-substituted-indole derivatives (10a-f), the indomethacin analogs were prepared via the Fisher indole synthesis reaction of propiophenone with appropriately substituted phenylhydrazine hydrochloride. This is followed by the insertion of the appropriate benzyl or benzoyl fragment. All the synthesized compounds were evaluated for their anti-inflammatory (in vitro and in vivo) and analgesic activities. The methanesulphonyl derivatives 10d, e and f showed the highest anti-inflammatory (in vitro and in vivo) and analgesic activities. In addition, molecular docking studies were performed on compounds 10a-f and the results were in agreement with that obtained from the in vitro COX inhibition assays. The significant anti-inflammatory and analgesic activities exhibited by 10d and 10e warrant continued preclinical development as potential anti-inflammatory and analgesic agents.

Stereospecific 1,4-addition to an alpha,beta-unsaturated steroidal epoxide: syntheses of new 15-oxygenated sterols.

PubMed

Parish, E J; Tsuda, M; Schroepfer, G J

1988-11-01

3 beta-Benzoyloxy-14 alpha,15 alpha-epoxy-5 alpha-cholest-7-ene (1) is a key intermediate in the synthesis of C-7 and C-15 oxygenated sterols. Treatment of 1 with benzoyl chloride resulted in the formation of 3 beta,15 alpha-bis-benzoyloxy-7 alpha-chloro-5 alpha-cholest-8(14)-ene (2). Reaction of 2 with LiAlH4 or LiAlD4 resulted in the formation of 5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3a) or [14 alpha-2H]5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3b). Diol 3b was selectively oxidized by Ag2CO3/celite to [14 alpha-2H]5 alpha-cholest-7-en-15 alpha-ol-3-one (4). Treatment of 1 with MeMgI/CuI gave 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 alpha-diol (5). Selective oxidation of 5 with pyridinium chlorochromate (PCC)/pyridine or oxidation with PCC resulted in the formation of 7 alpha-methyl-5 alpha-cholest-8(14)-en-3 beta-ol-15-one (6) and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3,15-dione, respectively. Reduction of 6 with LiAlH4 yielded 5 and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 beta-diol (6). Reaction of 1 with benzoic acid/pyridine gave 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-en-15 alpha-ol (9). Treatment of 9 with LiAlH4 or ethanolic KOH resulted in the formation of 5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol (10). Dibenzoate 9, upon brief treatment with mineral acid, gave 3 beta-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (11). Oxidation of 9 with PCC yielded 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (12). Ketone 12 was also prepared by the selective hydride reduction of 5 alpha-cholest-8(14)-en-7 alpha-ol-3,15-dione (13) to give 5 alpha-cholest-8(14)-ene-3 beta,7 alpha-diol-15-one (14), which was then treated with benzoyl chloride to produce 12.

Effects of luminal flow and nucleotides on [Ca(2+)](i) in rabbit cortical collecting duct.

PubMed

Woda, Craig B; Leite, Maurilo; Rohatgi, Rajeev; Satlin, Lisa M

2002-09-01

Nucleotide binding to purinergic P2 receptors contributes to the regulation of a variety of physiological functions in renal epithelial cells. Whereas P2 receptors have been functionally identified at the basolateral membrane of the cortical collecting duct (CCD), a final regulatory site of urinary Na(+), K(+), and acid-base excretion, controversy exists as to whether apical purinoceptors exist in this segment. Nor has the distribution of receptor subtypes present on the unique cell populations that constitute Ca(2+) the CCD been established. To examine this, we measured nucleotide-induced changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) in fura 2-loaded rabbit CCDs microperfused in vitro. Resting [Ca(2+)](i) did not differ between principal and intercalated cells, averaging approximately 120 nM. An acute increase in tubular fluid flow rate, associated with a 20% increase in tubular diameter, led to increases in [Ca(2+)](i) in both cell types. Luminal perfusion of 100 microM UTP or ATP-gamma-S, in the absence of change in flow rate, caused a rapid and transient approximately fourfold increase in [Ca(2+)](i) in both cell types (P < 0.05). Luminal suramin, a nonspecific P2 receptor antagonist, blocked the nucleotide- but not flow-induced [Ca(2+)](i) transients. Luminal perfusion with a P2X (alpha,beta-methylene-ATP), P2X(7) (benzoyl-benzoyl-ATP), P2Y(1) (2-methylthio-ATP), or P2Y(4)/P2Y(6) (UDP) receptor agonist had no effect on [Ca(2+)](i). The nucleotide-induced [Ca(2+)](i) transients were inhibited by the inositol-1,4,5-triphosphate receptor blocker 2-aminoethoxydiphenyl borate, thapsigargin, which depletes internal Ca(2+) stores, luminal perfusion with a Ca(2+)-free perfusate, or the L-type Ca(2+) channel blocker nifedipine. These results suggest that luminal nucleotides activate apical P2Y(2) receptors in the CCD via pathways that require both internal Ca(2+) mobilization and extracellular Ca(2+) entry. The flow-induced rise in [Ca(2+)](i) is

Synthesis of pyrimidin-2-one nucleosides as acid-stable inhibitors of cytidine deaminase.

PubMed

Kim, C H; Marquez, V E; Mao, D T; Haines, D R; McCormack, J J

1986-08-01

One of the problems encountered in the use of tetrahydrouridine (THU, 2) and saturated 2-oxo-1,3-diazepine nucleosides as orally administered cytidine deaminase (CDA) inhibitors is their acid instability. Under acid conditions these compounds are rapidly converted into inactive ribopyranoside forms. A solution this problem was sought by functionalizing the acid-stable but less potent CDA inhibitor 1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (1) with the hope of increasing its potency to the level achieved with THU. The selection of the hydroxymethyl substituent at C-4, which led to the synthesis of 4-(hydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (10), 3,4-dihydro-4-(hydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (7), and 3,4,5,6-tetrahydro-4-(dihydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-p yrimidinone (28) was based on the transition-state (TS) concept. The key intermediate precursor, 4-[(benzoyloxy)methyl]-1-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-2(H) -pyrimidinone (24), was obtained via the classical Hilbert-Johnson reaction between 2-methoxy-4-[(benzoyloxy)methyl]pyrimidine (20) and 2,3,5-tri-O-benzoyl-1-D-ribofuranosyl bromide (21). Deprotection of 24 afforded compound 10, while its sodium borohydride reduction products afforded compounds 7 and 28 after removal of the blocking groups. Syntheses of 3,4-dihydro-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (9) and 3,6-dihydro-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (8), which lack the hydroxymethyl substituent, was accomplished in a similar fashion. The new compounds bearing the hydroxymethyl substituent were more acid stable than THU, and their CDA inhibitory potency, expressed in terms of Ki values, spanned from 10(-4) to 10(-7) M in a manner consistent with the TS theory. Compound 7, in particular, was superior to its parent 1 and equipotent to THU (Ki = 4 X 10(-7) M) when examined against mouse kidney CDA. The superior acid stability of this compound coupled to its potent inhibitory

Nucleotides induce chemotaxis and actin polymerization in immature but not mature human dendritic cells via activation of pertussis toxin-sensitive P2y receptors.

PubMed

Idzko, Marco; Dichmann, Stefan; Ferrari, Davide; Di Virgilio, Francesco; la Sala, Andrea; Girolomoni, Giampiero; Panther, Elisabeth; Norgauer, Johannes

2002-08-01

Dendritic cells (DCs) are considered the principal initiators of immune response because of their ability to migrate into peripheral tissues and lymphoid organs, process antigens, and activate naive T cells. There is evidence that extracellular nucleotides regulate certain functions of DCs via G-protein-coupled P2Y receptors (P2YR) and ion-channel-gated P2X receptors (P2XR). Here we investigated the chemotactic activity and analyzed the migration-associated intracellular signaling events such as actin reorganization and Ca(++) transients induced by common P2R agonists such as adenosine 5'-triphosphate (ATP) and 2-methylthioadenosine triphosphate, the P2YR agonists UTP and adenosine 5'-diphosphate (ADP), or the P2XR agonists alphabeta-methylenadenosine-5'-triphosphate and 2',3'-(4-benzoyl)benzoyl-ATP. The common P2R agonists and the selective P2YR agonists turned out to be potent chemotactic stimuli for immature DCs, but not for mature DCs. In contrast, P2XR agonists had only marginal chemotactic activity in both DC types. Chemotaxis was paralleled by a rise in the intracellular Ca(++) concentration and by actin polymerization. Studies with pertussis toxin implicated that intracellular signaling events such as actin polymerization, mobilization of intracellular Ca(++), and migration induced by nucleotides was mediated via G(i/o) protein-coupled P2YR. Moreover, functional studies revealed selective down-regulation of this G(i/o) protein-coupled chemotactic P2YR responsiveness during maturation, although immature and mature DCs expressed similar amounts of mRNA for the P2R subtypes (P2Y(2)R, P2Y(4)R, P2Y(5)R, P2Y(7)R, P2Y(11)R and P2X(1)R, P2X(4)R, P2X(7)R), and no major differences in respect to the mRNA expression of these receptors could be observed by semiquantitative reverse transcription and polymerase chain reaction (RT-PCR). In summary, our data describe a differential chemotactic response of immature and mature DCs to nucleotides, and lend further support to

[Total analysis of organic rubber additives].

PubMed

He, Wen-Xuan; Robert, Shanks; You, Ye-Ming

2010-03-01

In the present paper, after middle pressure chromatograph separation using both positive phase and reversed-phase conditions, the organic additives in ethylene-propylene rubber were identified by infrared spectrometer. At the same time, by using solid phase extraction column to maintain the main component-fuel oil in organic additves to avoid its interfering with minor compounds, other organic additves were separated and analysed by GC/Ms. In addition, the remaining active compound such as benzoyl peroxide was identified by CC/Ms, through analyzing acetone extract directly. Using the above mentioned techniques, soften agents (fuel oil, plant oil and phthalte), curing agent (benzoylperoxide), vulcanizing accelerators (2-mercaptobenzothiazole, ethyl thiuram and butyl thiuram), and antiagers (2, 6-Di-tert-butyl-4-methyl phenol and styrenated phenol) in ethylene-propylene rubber were identified. Although the technique was established in ethylene-propylene rubber system, it can be used in other rubber system.

New 1,6-heptadienes with pyrimidine bases attached: Syntheses and spectroscopic analyses

NASA Astrophysics Data System (ADS)

Hammud, Hassan H.; Ghannoum, Amer M.; Fares, Fares A.; Abramian, Lara K.; Bouhadir, Kamal H.

2008-06-01

A simple, high yielding synthesis leading to the functionalization of some pyrimidine bases with a 1,6-heptadienyl moiety spaced from the N - 1 position by a methylene group is described. A key step in this synthesis involves a Mitsunobu reaction by coupling 3N-benzoyluracil and 3N-benzoylthymine to 2-allyl-pent-4-en-1-ol followed by alkaline hydrolysis of the 3N-benzoyl protecting groups. This protocol should eventually lend itself to the synthesis of a host of N-alkylated nucleoside analogs. The absorption and emission properties of these pyrimidine derivatives ( 3- 6) were studied in solvents of different physical properties. Computerized analysis and multiple regression techniques were applied to calculate the regression and correlation coefficients based on the equation that relates peak position λmax to the solvent parameters that depend on the H-bonding ability, refractive index, and dielectric constant of solvents.

Identification of potent orally active factor Xa inhibitors based on conjugation strategy and application of predictable fragment recommender system.

PubMed

Ishihara, Tsukasa; Koga, Yuji; Iwatsuki, Yoshiyuki; Hirayama, Fukushi

2015-01-15

Anticoagulant agents have emerged as a promising class of therapeutic drugs for the treatment and prevention of arterial and venous thrombosis. We investigated a series of novel orally active factor Xa inhibitors designed using our previously reported conjugation strategy to boost oral anticoagulant effect. Structural optimization of anthranilamide derivative 3 as a lead compound with installation of phenolic hydroxyl group and extensive exploration of the P1 binding element led to the identification of 5-chloro-N-(5-chloro-2-pyridyl)-3-hydroxy-2-{[4-(4-methyl-1,4-diazepan-1-yl)benzoyl]amino}benzamide (33, AS1468240) as a potent factor Xa inhibitor with significant oral anticoagulant activity. We also reported a newly developed Free-Wilson-like fragment recommender system based on the integration of R-group decomposition with collaborative filtering for the structural optimization process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of eight glycols in serum using LC-ESI-MS-MS.

PubMed

Imbert, Laurent; Saussereau, Elodie; Lacroix, Christian

2014-01-01

A liquid chromatography coupled with electrospray tandem mass spectrometry method was developed for the analysis of ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,2-butanediol, 2,3-butanediol, 1,2-propanediol and 1,3-propanediol, in serum after a Schotten-Baumann derivatization by benzoyl chloride. Usual validation parameters were tested: linearity, repeatability and intermediate precision, limits of detection and quantification, carry over and ion suppression. Limits of detection were between 0.18 and 1.1 mg/L, and limits of quantification were between 0.4 and 2.3 mg/L. Separation of isomers was possible either chromatographically or by selecting specific multiple reaction monitoring transitions. This method could be a useful tool in case of suspected intoxication with antifreeze agents, solvents, dietary supplements or some medical drug compounds. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Properties of chymotrypsin bound covalently to dextran.

PubMed

Zlateva, T P; Krysteva, M; Balajthy, Z; Elödi, P

1988-01-01

The kinetic properties dextran-chymotrypsin conjugate were studied by means of low molecular weight substrates. It was found that KM, kcat and kcat/KM of dextran chymotrypsin for the hydrolysis of benzoyl-L-tyrosine-ethyl-ester did not differ substantially from those of the free enzyme. However, the data found for kcat of dextran-chymotrypsin and free chymotrypsin assayed for the hydrolysis of three tripeptidyl-p-nitroanilide D-Arg-Val-Trp-pNA, D-Arg-Val-Tyr-pNA, Z-Phe-Pro-Phe-pNA, were definitely different. The inhibition of the modified chymotrypsin with soybean trypsin inhibitor was found to be less pronounced than that with the free enzyme. The effect of potassium and magnesium salts on the inactivation of both enzymes was also studied. The effect of dextran matrix on the catalytic properties and the conformational stability of modified chymotrypsin is discussed.

Oxygen-Controlled Catalysis by Vitamin B12 -TiO2 : Formation of Esters and Amides from Trichlorinated Organic Compounds by Photoirradiation.

PubMed

Shimakoshi, Hisashi; Hisaeda, Yoshio

2015-12-14

An oxygen switch in catalysis of the cobalamin derivative (B12 )-TiO2 hybrid catalyst for the dechlorination of trichlorinated organic compounds has been developed. The covalently bound B12 on the TiO2 surface transformed trichlorinated organic compounds into an ester and amide by UV light irradiation under mild conditions (in air at room temperature), while dichlorostilbenes (E and Z forms) were formed in nitrogen from benzotrichloride. A benzoyl chloride was formed as an intermediate of the ester and amide, which was detected by GC-MS. The substrate scope of the synthetic strategy is demonstrated with a range of various trichlorinated organic compounds. A photo-duet reaction utilizing the hole and conduction band electron of TiO2 in B12 -TiO2 for the amide formation was also developed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystal structure of 4-meth­oxy-N-(piperidine-1-carbono­thio­yl)benzamide

PubMed Central

Suhud, Khairi; Hasbullah, Siti Aishah; Ahmad, Musa; Heng, Lee Yook

2017-01-01

In the title compound, C14H18N2O2S, the piperidine ring has a chair conformation. Its mean plane is twisted with respect to the 4-meth­oxy­benzoyl ring, with a dihedral angle of 63.0 (3)°. The central N—C(=S)—N(H)—C(=O) bridge is twisted with an N—C—N—C torsion angle of 74.8 (6)°. In the crystal, mol­ecules are linked by N—H⋯O and C—H⋯O hydrogen bonds, forming chains along the c-axis direction. Adjacent chains are linked by C—H⋯π inter­actions, forming layers parallel to the ac plane. The layers are linked by offset π–π inter­actions [inter­centroid distance = 3.927 (3) Å], forming a supra­molecular three-dimensional structure. PMID:29250374

Key factor affecting the structural and textural properties of ZSM-5/MCM-41 composite

NASA Astrophysics Data System (ADS)

Boukoussa, Bouhadjar; Aouad, Nafissa; Hamacha, Rachida; Bengueddach, Abdelkader

2015-03-01

ZSM-5/MCM-41 micro/mesoporous composite materials were synthesized by the hydrothermal technique with alkali-treated ZSM-5 zeolite as source of silica and aluminum and characterized by various physico-chemical techniques such as X-ray diffraction (XRD), nitrogen sorption at 77 K, transmission electronic microscopy (TEM), FTIR spectroscopy and NH3 temperature programmed desorption (TPD) techniques. The effect of concentration of CTAB in the synthesis of these solids has been investigated, the mesopore volume, surface area and surface acidity decrease with increasing the concentration of CTAB. Increasing the CTAB concentration causes the recrystallization of zeolite ZSM-5 and it disadvantage the formation of mesoporous materials MCM-41. The catalytic activity of ZSM-5/MCM-41 materials has been evaluated in the Friedel-Crafts acylation of anisole with benzoyl chloride as alkylating agent. The results revealed the reaction to be influenced by surface area, pore volume and surface acidity.

Aflaquinolones A-G: secondary metabolites from marine and fungicolous isolates of Aspergillus spp.

PubMed

Neff, Scott A; Lee, Sang Un; Asami, Yukihiro; Ahn, Jong Seog; Oh, Hyuncheol; Baltrusaitis, Jonas; Gloer, James B; Wicklow, Donald T

2012-03-23

Seven new compounds (aflaquinolones A-G; 1-7) containing dihydroquinolin-2-one and terpenoid units have been isolated from two different fungal sources. Two of these metabolites (1 and 2) were obtained from a Hawaiian fungicolous isolate of Aspergillus sp. (section Flavipedes; MYC-2048 = NRRL 58570), while the others were obtained from a marine Aspergillus isolate (SF-5044) collected in Korea. The structures of these compounds were determined mainly by analysis of NMR and MS data. Relative and absolute configurations were assigned on the basis of NOESY data and (1)H NMR J-values, comparison of calculated and experimental ECD spectra, and analysis of a Mosher's ester derivative of 2. Several known compounds, including alantrypinone, aspochalasins I and J, methyl 3,4,5-trimethoxy-2((2-((3-pyridinylcarbonyl)amino)benzoyl)amino)benzoate, and trans-dehydrocurvularin were also encountered in the extract of the Hawaiian isolate.

Excitability in chemical and biochemical pH-autocatalytic systems.

PubMed

Zagora, J; Voslar, M; Schreiberová, L; Schreiber, I

2001-01-01

Using two different kinds of pH systems--the papain catalyzed hydrolysis of N-benzoyl-L-arginine ethyl ester in a membrane reactor and the bromate-sulfite-ferrocyanide (BSF) reaction in the CSTR--we study the relation among excitability, oscillations and bistability, and the ability of the system to respond to external periodic perturbations. Excitable properties of dynamical systems are examined in terms of a threshold set which is used to characterise dynamics in the reactor subject to external periodic stimuli. A precise definition and a method of calculating the threshold set are formulated. Two kinds of excitability distinguished by either direct or indirect initiation of the activatory process are found in both pH systems. Periodic pulsed perturbations of the BSF system display a nontrivial dependence of an excitation number on the forcing period. We examined this system also in oscillatory mode by looking at the phase shifts caused by single-pulse perturbations and constructing the phase transition curves (PTCs).

Dissipation of the Herbicide Benzobicyclon Hydrolysate in a Model California Rice Field Soil.

PubMed

Williams, Katryn L; Gladfelder, Joshua J; Quigley, Lindsay L; Ball, David B; Tjeerdema, Ronald S

2017-10-25

The herbicide benzobicyclon (BZB; 3-(2-chloro-4-(methylsulfonyl)benzoyl)-2-phenylthiobicyclo[3.2.1]oct-2-en-4-one) has recently been approved for use on California rice fields by the United States Environmental Protection Agency (U.S. EPA). Hydrolysis of BZB rapidly forms the active compound, benzobicyclon hydrolysate (BH), whose fate is currently not well understood. A model California rice soil was used to determine BH soil dissipation. The pK a and aqueous solubility were also determined, as experimental values are not currently available. Sorption data indicate BH does not bind tightly, or irreversibly, with this soil. Flooding resulted in decreased BH loss, indicating anaerobic microbes are less likely to transform BH compared to aerobic microorganisms. Temperature increased dissipation, while autoclaving decreased BH loss. Overall, dissipation was slow regardless of treatment. Further investigation is needed to elucidate the exact routes of loss in soil, though BH is expected to dissipate slowly in flooded rice field soil.

Determination of alternative preservatives in cosmetic products by chromophoric derivatization followed by vortex-assisted liquid-liquid semimicroextraction and liquid chromatography.

PubMed

Miralles, Pablo; Vrouvaki, Ilianna; Chisvert, Alberto; Salvador, Amparo

2016-07-01

An analytical method for the simultaneous determination of phenethyl alcohol, methylpropanediol, phenylpropanol, caprylyl glycol, and ethylhexylglycerin, which are used as alternative preservatives in cosmetic products, has been developed. The method is based on liquid chromatography with UV spectrophotometric detection after chromophoric derivatization with benzoyl chloride and vortex-assisted liquid-liquid semimicroextraction. Different chromatographic parameters, derivatization conditions, and sample preparation variables were studied. Under optimized conditions, the limits of detection values for the analytes ranged from 0.02 to 0.06µgmL(-1). The method was validated with good recovery values (84-118%) and precision values (3.9-9.5%). It was successfully applied to 10 commercially available cosmetic samples. The good analytical features of the proposed method besides of its environmentally-friendly characteristics, make it useful to carry out the quality control of cosmetic products containing the target compounds as preservative agents. Copyright © 2016 Elsevier B.V. All rights reserved.

Fiber-optic Singlet Oxygen [1O2 (1Δg)] Generator Device Serving as a Point Selective Sterilizer

PubMed Central

Aebisher, David; Zamadar, Matibur; Mahendran, Adaickapillai; Ghosh, Goutam; McEntee, Catherine; Greer, Alexander

2016-01-01

Traditionally, Type II heterogeneous photo-oxidations produce singlet oxygen via external irradiation of a sensitizer and external supply of ground-state oxygen. A potential improvement is reported here. A hollow-core fiber-optic device was developed with an “internal” supply of light and flowing oxygen, and a porous photosensitizer-end capped configuration. Singlet oxygen was delivered through the fiber tip. The singlet oxygen steady-state concentration in the immediate vicinity of the probe tip was ca 20 fM by N-benzoyl-DL-methionine trapping. The device is portable and the singlet oxygen-generating tip is maneuverable, which opened the door to simple disinfectant studies. Complete Escherichia coli inactivation was observed in 2 h when the singlet oxygen sensitizing probe tip was immersed in 0.1 mL aqueous samples of 0.1–4.4 × 107 cells. Photobleaching of the probe tip occurred after ca 12 h of use, requiring baking and sensitizer reloading steps for reuse. PMID:20497367

Inhibitors of COP-mediated Transport and Cholera Toxin Action Inhibit Simian Virus 40 Infection

PubMed Central

Richards, Ayanthi A.; Stang, Espen; Pepperkok, Rainer; Parton, Robert G.

2002-01-01

Simian virus 40 (SV40) is a nonenveloped virus that has been shown to pass from surface caveolae to the endoplasmic reticulum in an apparently novel infectious entry pathway. We now show that the initial entry step is blocked by brefeldin A and by incubation at 20°C. Subsequent to the entry step, the virus reaches a domain of the rough endoplasmic reticulum by an unknown pathway. This intracellular trafficking pathway is also brefeldin A sensitive. Infection is strongly inhibited by expression of GTP-restricted ADP-ribosylation factor 1 (Arf1) and Sar1 mutants and by microinjection of antibodies to βCOP. In addition, we demonstrate a potent inhibition of SV40 infection by the dipeptide N-benzoyl-oxycarbonyl-Gly-Phe-amide, which also inhibits late events in cholera toxin action. Our results identify novel inhibitors of SV40 infection and show that SV40 requires COPI- and COPII-dependent transport steps for successful infection. PMID:12006667

An expedient synthesis of N-(1-(5-mercapto-4-((substituted benzylidene)amino)-4H-1,2,4-triazol-3-yl)-2-phenylethyl)benzamides as jack bean urease inhibitors and free radical scavengers: Kinetic mechanism and molecular docking studies.

PubMed

Saeed, Aamer; Larik, Fayaz Ali; Channar, Pervaiz Ali; Mehfooz, Haroon; Ashraf, Mohammad Haseeb; Abbas, Qamar; Hassan, Mubashir; Seo, Sung-Yum

2017-11-01

In this study, some new azomethine-triazole hybrids 5a-5l derived from N-benzoyl-L-phenylalanine were synthesized and characterized. The synthesized compounds showed first-rate, urease inhibition, and compounds 5c and 5e were found to be most effective inhibitors with 0.0137 ± 0.00082 μm and 0.0183 ± 0.00068 μm, respectively (thiourea 15.151 ± 1.27 μm). The kinetic mechanism of urease inhibition revealed the compounds 5c and 5e to be non-competitive inhibitors, whereas compounds 5d and 5j were found to be of mixed-type inhibitors. Docking studies also indicated better interaction patterns with urease enzyme. The results of enzyme inhibition, kinetic mechanism and molecular docking suggest that these compounds can serve as lead compounds in the design of more effective urease inhibitors. © 2017 John Wiley & Sons A/S.

Effects of plant phenols of performance of southern armyworm larvae.

PubMed

Lindroth, R L; Peterson, S S

1988-03-01

We evaluated the effects of two classes of phenols on performance of penultimate instar southern armyworms, Spodoptera eridania. One class consisted of phenols containing a catechol (ortho-dihydroxybenzene) moiety and included chlorogenic acid, quercetin, rutin, and rhamnetin. A second group consisted of the phenolic glycoside salicin and its derivatives salicortin and tremulacin. The compounds were painted onto lima bean (Phaseolus lunatus) leaves and fed to larvae for the duration of the fifth instar. Chlorogenic acid and rhamnetin had no deleterious effects; rutin and quercetin caused some mortality and rutin reduced growth rates by decreasing consumption and digestion efficiency. Results showed that ortho-dihydroxybenzene groups may be necessary, but are not sufficient for biological activity. Salicin did not affect larvae; salicortin and tremulacin reduced growth rates primarily by decreasing consumption. These two compounds also caused degenerative lesions in midgut tissues. The presence of a benzoyl ester group in tremulacin accentuates its toxicity, relative to that of salicortin.

Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24.

PubMed

Lee, Sang-Yeop; Kim, Gun-Hwa; Yun, Sung Ho; Choi, Chi-Won; Yi, Yoon-Sun; Kim, Jonghyun; Chung, Young-Ho; Park, Edmond Changkyun; Kim, Seung Il

2016-01-01

Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs), including benzene, toluene, and xylene (BTX), as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX.

Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24

PubMed Central

Yun, Sung Ho; Choi, Chi-Won; Yi, Yoon-Sun; Kim, Jonghyun; Chung, Young-Ho; Park, Edmond Changkyun; Kim, Seung Il

2016-01-01

Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs), including benzene, toluene, and xylene (BTX), as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX. PMID:27124467

Synthesis, spectroscopic properties and theoretical studies of bis-Schiff bases derived from polyamine and pyrazolones.

PubMed

Ren, Tiegang; Liu, Shuyun; Li, Guihui; Zhang, Jinglai; Guo, Jia; Li, Weijie; Yang, Lirong

2012-11-01

A series of novel bis-Schiff base were synthesized from 1-aryl-3-methyl-4-benzoyl-5-pyrazolones and diethylenetriamine (or triethylenetetramine) as the starting materials. All of these bis-Schiff bases were characterized by means of NMR, IR, and MS. The UV-vis absorption spectra and fluorescent spectra of these bis-Schiff bases were also measured. Moreover, the B3LYP/6-31G(d) method was used to optimize the ground state geometry of the bis-Schiff bases; and the UV-vis spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVDZ basis set of TD-B3LYP method. It has been found that all of these bis-Schiff bases show a remarkable absorption peak in a wavelength range of 270-340 nm; and their maximum emission peaks are around 348 nm. Copyright © 2012 Elsevier B.V. All rights reserved.

Quantitation of Flavanols, Proanthocyanidins, Isoflavones, Flavanones, Dihydrochalcones, Stilbenes, Benzoic Acid Derivatives Using Ultraviolet Absorbance after Identification by Liquid Chromatography–Mass Spectrometry

PubMed Central

Lin, Long-Ze; Harnly, James M.

2013-01-01

A general method was developed for the systematic quantitation of flavanols, proanthocyanidins, isoflavones, flavanones, dihydrochalcones, stilbenes, and hydroxybenzoic acid derivatives (mainly hydrolyzable tannins) based on UV band II absorbance arising from the benzoyl structure. The compound structures and the wavelength maximum were well correlated and were divided into four groups: the flavanols and proanthocyanidins at 278 nm, hydrolyzable tannins at 274 nm, flavanones at 288 nm, and isoflavones at 260 nm. Within each group, molar relative response factors (MRRFs) were computed for each compound based on the absorbance ratio of the compound and the group reference standard. Response factors were computed for the compounds as purchased (MRRF), after drying (MRRFD), and as the best predicted value (MRRFP). Concentrations for each compound were computed based on calibration with the group reference standard and the MRRFP. The quantitation of catechins, proanthocyanidins, and gallic acid derivatives in white tea was used as an example. PMID:22577798

Polymer concrete composites for the production of high strength pipe and linings in high temperature corrosive environments

DOEpatents

Zeldin, A.; Carciello, N.; Fontana, J.; Kukacka, L.

High temperature corrosive resistant, non-aqueous polymer concrete composites are described. They comprise about 12 to 20% by weight of a water-insoluble polymer binder polymerized in situ from a liquid monomer mixture consisting essentially of about 40 to 70% by weight of styrene, about 25 to 45% by weight acrylonitrile and about 2.5 to 7.5% by weight acrylamide or methacrylamide and about 1 to 10% by weight of a crosslinking agent. This agent is selected from the group consisting of trimethylolpropane trimethacrylate and divinyl benzene; and about 80 to 88% by weight of an inert inorganic filler system containing silica sand and portland cement, and optionally Fe/sub 2/O/sub 3/ or carbon black or mica. A free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, other organic peroxides and combinations thereof to initiate crosspolymerization of the monomer mixture in the presence of said inorganic filler.

Cyclohex-1-ene carboxylic acids: synthesis and biological evaluation of novel inhibitors of human 5 alpha reductase.

PubMed

Baston, Eckhard; Salem, Ola I A; Hartmann, Rolf W

2003-03-01

In search of novel nonsteroidal mimics of steroidal inhibitors of 5 alpha reductase, 4-(2-phenylethyl)cyclohex-1-ene carboxylic acids 1-5 were synthesized with different substituents in para position of the phenyl ring (1: N, N-diisopropylcarbamoyl, 2: phenyl, 3: phenoxy, 4: benzoyl, and 5: benzyl). The principal synthetic approach for the desired compounds consisted of a Wittig olefination between 1, 4-dioxaspiro [4.5]-decane-8-carbaldehyde (4g and the appropriate phosphonium salts. The compounds were tested for inhibition of human 5 alpha reductase isozymes 1 and 2 using DU 145 cells and preparations from prostatic tissue, respectively. They turned out to be good inhibitors of the prostatic isozyme 2 with compound 1 being the most potent one (IC(50) = 760 nM). Isozyme 1 was only slightly inhibited. It is concluded that the novel structures are appropriate for being further optimized, aiming at the development of a novel drug for the treatment of benign prostatic hyperplasia.

Isolation of tungsten and tantalum isotopes without supports from. cap alpha. -particle-irradiated hafnium targets

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

Gasita, S.M.; Iota, B.Z.; Malachkov, A.G.

1985-11-01

An extraction procedure has been developed for successive isolation of tungsten (/sup 178/W and /sup 181/W) and tantalum (/sup 179/Ta and /sup 182/Ta) isotopes without supports from ..cap alpha..particle-irradiated hafnium targets. The target, irradiated on a cyclotron, is dissolved in hydrofluoric acid. Tantalum isotopes are extracted with tributyl phosphate (TBP) from 1-5 M HF and are then reextracted with a 1:1 ammonia solution, and hydrofluoric acid is removed by heating. Tungsten isotopes are extracted with a chloroform solution or N-benzoyl-N-phenylhydroxylamine (BPHA) from 11-12 M H/sub 2/SO/sub 4/ or ..cap alpha..-benzoin oxime from 4.5-5.5 M H/sub 2/SO/sub 4/ and are thenmore » reextracted with a l:l ammonia solution. The yield of tungsten isotopes is not less than 95%, and the content of radioactive impurities of other isotopes is not more than 0.1%.« less

Synthesis and decomposition of a novel carboxylate precursor to indium oxide

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Andras, Maria T.; Duraj, Stan A.; Clark, Eric B.; Hehemann, David G.; Scheiman, Daniel A.; Fanwick, Phillip E.

1994-01-01

Reaction of metallic indium with benzoyl peroxide in 4-1 methylpyridine (4-Mepy) at 25 C produces an eight-coordinate mononuclear indium(III) benzoate, In(eta(sup 2)-O2CC6H5)3(4-Mepy)2 4H2O (I), in yields of up to 60 percent. The indium(III) benzoate was fully characterized by elemental analysis, spectroscopy, and X-ray crystallography; (I) exists in the crystalline state as discrete eight-coordinate molecules; the coordination sphere around the central indium atom is best described as pseudo-square pyramidal. Thermogravimetric analysis of (I) and X-ray diffraction powder studies on the resulting pyrolysate demonstrate that this new benzoate is an inorganic precursor to indium oxide. Decomposition of (I) occurs first by loss of 4-methylpyridine ligands (100 deg-200 deg C), then loss of benzoates with formation of In2O3 at 450 C. We discuss both use of carboxylates as precursors and our approach to their preparation.

The Last Step in Cocaine Biosynthesis Is Catalyzed by a BAHD Acyltransferase[OPEN

PubMed Central

Schmidt, Gregor Wolfgang; Porta, Tiffany; Reichelt, Michael; Luck, Katrin; Torre, José Carlos Pardo; Dolke, Franziska; Varesio, Emmanuel; Hopfgartner, Gérard; Gershenzon, Jonathan

2015-01-01

The esterification of methylecgonine (2-carbomethoxy-3β-tropine) with benzoic acid is the final step in the biosynthetic pathway leading to the production of cocaine in Erythoxylum coca. Here we report the identification of a member of the BAHD family of plant acyltransferases as cocaine synthase. The enzyme is capable of producing both cocaine and cinnamoylcocaine via the activated benzoyl- or cinnamoyl-Coenzyme A thioesters, respectively. Cocaine synthase activity is highest in young developing leaves, especially in the palisade parenchyma and spongy mesophyll. These data correlate well with the tissue distribution pattern of cocaine as visualized with antibodies. Matrix-assisted laser-desorption ionization mass spectral imaging revealed that cocaine and cinnamoylcocaine are differently distributed on the upper versus lower leaf surfaces. Our findings provide further evidence that tropane alkaloid biosynthesis in the Erythroxylaceae occurs in the above-ground portions of the plant in contrast with the Solanaceae, in which tropane alkaloid biosynthesis occurs in the roots. PMID:25406120

Synthesis and properties of shape memory polyurethanes generated from schiff-base chain extender containing benzoyl and pyridyl rings

PubMed Central

Weng, Neng-Chiao; Wu, Chih-Fu; Tsen, Wen-Chin; Wu, Cheng-Lung; Suen, Maw-Cherng

2018-01-01

Abstract In this study, 4,4′-diphenylmethane diisocyanate and polytetramethylene glycol were used to prepare a prepolymer; N,N′-bis(4-hydroxybenzylidene)-2,6-diaminopyridine (BHBP) was used as a chain extender; and these elements were combined to prepare a novel polyurethane, BHBP/PU. Gel permeation chromatography revealed that the molecular weight of the BHBP/PU samples increased as the BHBP content was increased. Fourier transform infrared spectroscopy demonstrated that high BHBP content facilitated strong hydrogen bonding in the samples. Differential thermogravimetry indicated that the initial decomposition temperature of BHBP/PU-3 was approximately 10 °C higher than that of BHBP/PU-1. Differential scanning calorimetry and dynamic mechanical analysis revealed that increasing the BHBP content substantially increased both the glass transition and dynamic glass transition temperatures of the BHBP/PU samples. The tensile strengths of BHBP/PU-1, BHBP/PU-2, and BHBP/PU-3 were 7.7, 10.9, and 21.6 MPa, respectively, with corresponding Young’s moduli of 0.7, 1.9, and 3.3 MPa. These results demonstrated that both the tensile strength and Young’s modulus of the BHBP/PU samples increased as the BHBP content was increased. Moreover, the BHBP/PU samples exhibited excellent shape recovery of >90%. PMID:29706848

Rapid determination and chemical change tracking of benzoyl peroxide in wheat flour by multi-step IR macro-fingerprinting.

PubMed

Guo, Xiao-Xi; Hu, Wei; Liu, Yuan; Sun, Su-Qin; Gu, Dong-Chen; He, Helen; Xu, Chang-Hua; Wang, Xi-Chang

2016-02-05

BPO is often added to wheat flour as flour improver, but its excessive use and edibility are receiving increasing concern. A multi-step IR macro-fingerprinting was employed to identify BPO in wheat flour and unveil its changes during storage. BPO contained in wheat flour (<3.0 mg/kg) was difficult to be identified by infrared spectra with correlation coefficients between wheat flour and wheat flour samples contained BPO all close to 0.98. By applying second derivative spectroscopy, obvious differences among wheat flour and wheat flour contained BPO before and after storage in the range of 1500-1400 cm(-1) were disclosed. The peak of 1450 cm(-1) which belonged to BPO was blue shifted to 1453 cm(-1) (1455) which belonged to benzoic acid after one week of storage, indicating that BPO changed into benzoic acid after storage. Moreover, when using two-dimensional correlation infrared spectroscopy (2DCOS-IR) to track changes of BPO in wheat flour (0.05 mg/g) within one week, intensities of auto-peaks at 1781 cm(-1) and 669 cm(-1) which belonged to BPO and benzoic acid, respectively, were changing inversely, indicating that BPO was decomposed into benzoic acid. Moreover, another autopeak at 1767 cm(-1) which does not belong to benzoic acid was also rising simultaneously. By heating perturbation treatment of BPO in wheat flour based on 2DCOS-IR and spectral subtraction analysis, it was found that BPO in wheat flour not only decomposed into benzoic acid and benzoate, but also produced other deleterious substances, e.g., benzene. This study offers a promising method with minimum pretreatment and time-saving to identify BPO in wheat flour and its chemical products during storage in a holistic manner. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and X-ray crystal structure determination of N- p-methylphenyl-4-benzoyl-3,4-diphenyl-2-azetidinone

NASA Astrophysics Data System (ADS)

Kabak, Mehmet; Şenöz, Hülya; Elmali, Ayhan; Adar, Vildan; Svoboda, Ingrid; Dušek, Michal; Fejfarová, Karla

2010-12-01

The title compound, C29H23NO2, has been characterized by single-crystal X-ray diffraction at two different temperatures (303 K and 120 K) and wavelengths (Mo K α and Cu K α). The non-centrosymmetric hexagonal crystal structure contains four-membered planar β-lactam ring with an unusually long C-C bond. The β-lactam ring is almost planar.

Novel channel-mediated choline transport in cholinergic neurons of the mouse retina.

PubMed

Ishii, Toshiyuki; Homma, Kohei; Mano, Asuka; Akagi, Takumi; Shigematsu, Yasuhide; Shimoda, Yukio; Inoue, Hiroyoshi; Kakinuma, Yoshihiko; Kaneda, Makoto

2017-10-01

Choline uptake into the presynaptic terminal of cholinergic neurons is mediated by the high-affinity choline transporter and is essential for acetylcholine synthesis. In a previous study, we reported that P2X 2 purinoceptors are selectively expressed in OFF-cholinergic amacrine cells of the mouse retina. Under specific conditions, P2X 2 purinoceptors acquire permeability to large cations, such as N -methyl-d-glucamine, and therefore potentially could act as a noncanonical pathway for choline entry into neurons. We tested this hypothesis in OFF-cholinergic amacrine cells of the mouse retina. ATP-induced choline currents were observed in OFF-cholinergic amacrine cells, but not in ON-cholinergic amacrine cells, in mouse retinal slice preparations. High-affinity choline transporters are expressed at higher levels in ON-cholinergic amacrine cells than in OFF-cholinergic amacrine cells. In dissociated preparations of cholinergic amacrine cells, ATP-activated cation currents arose from permeation of extracellular choline. We also examined the pharmacological properties of choline currents. Pharmacologically, α,β-methylene ATP did not produce a cation current, whereas ATPγS and benzoyl-benzoyl-ATP (BzATP) activated choline currents. However, the amplitude of the choline current activated by BzATP was very small. The choline current activated by ATP was strongly inhibited by pyridoxalphosphate-6-azophenyl-2',4'-sulfonic acid. Accordingly, P2X 2 purinoceptors expressed in HEK-293T cells were permeable to choline and similarly functioned as a choline uptake pathway. Our physiological and pharmacological findings support the hypothesis that P2 purinoceptors, including P2X 2 purinoceptors, function as a novel choline transport pathway and may provide a new regulatory mechanism for cholinergic signaling transmission at synapses in OFF-cholinergic amacrine cells of the mouse retina. NEW & NOTEWORTHY Choline transport across the membrane is exerted by both the high-affinity and

Rate of Adverse Events and Healthcare Costs Associated with the Topical Treatment of Rosacea.

PubMed

Williamson, Todd; Kamalakar, Rajesh; Ogbonnaya, Augustina; Zagadailov, Erin A; Eaddy, Michael; Kreilick, Charlie

2017-05-01

Rosacea is a condition more common in women than in men, and in people aged ≥30 years than in younger patients. Adverse events associated with the use of topical medications for rosacea may lead to a lack of treatment adherence. Previous studies have reported low treatment adherence rates among patients with rosacea. To describe the rate of treatment discontinuation resulting from adverse events and the associated healthcare costs among patients with rosacea who are receiving a topical medication. We conducted a retrospective cohort study of patients diagnosed with rosacea based on International Classification of Diseases, Ninth Revision, Clinical Modification code 695.3 who were newly initiating topical treatment with metronidazole, azelaic acid, sodium sulfacetamide/sulfur, or benzoyl peroxide between January 1, 2009, and September 30, 2013. Patients were identified from the MarketScan Commercial Claims and Encounters database and the Medicare Supplemental database and had to be aged ≥30 years, have continuous coverage with medical and pharmacy benefits ≥12 months before treatment and ≥3 months after treatment inititation, and have no evidence of oral antibiotic use or ocular rosacea during the study period. The 3-month period immediately after the index date (ie, first topical rosacea treatment) was defined as the postindex period and was used to evaluate the outcome measures, which included the rate of adverse events, treatment patterns, and healthcare costs. The final cohort included 49,351 patients, with a mean age of 54 years, and 74.5% of the patients were female. Metronidazole was the most common (72.7%) treatment, followed by azelaic acid (21.7%), sodium sulfacetamide/sulfur (3.4%), and benzoyl peroxide (2.2%). A total of 6270 (12.7%) patients had a coded adverse event, of whom 199 (3.2%) continued treatment despite the adverse event, 466 (7.4%) switched to another treatment within 8.8 days, and 5605 (89.4%) discontinued therapy within 31.1 days

Effect of N-benzoyl-D-phenylalanine, a new potential oral antidiabetic agent, in neonatal streptozotocin-induced diabetes in rats.

PubMed

Pari, Leelavinothan; Ashokkumar, Natarajan

2005-01-01

The present investigation was undertaken to study the effect of treatment with D-phenylalanine derivative and metformin in neonatal streptozotocin (nSTZ)-induced non-insulin-dependent diabetes mellitus (NIDDM) in rats. To induce NIDDM, a single dose injection of streptozotozin (STZ) (100 mg kg(-1); ip) was given to 2-day-old rats. After 10-12 weeks, rats weighing above 150 g were selected for screening in NIDDM model. They were checked for fasting blood glucose levels to conform the status of NIDDM. D-phenylalanine derivative (50, 100 and 200 mg kg(-1)) was administered per os (po) for 6 weeks to the rats with confirmed diabetes. A group of diabetic rats was also maintained and this group received metformin as comparative drug. Significant decrease in blood glucose with significant increase in plasma insulin was observed in group receiving 100 mg of D-phenylalanine derivative plus 500 mg of metformin.

Onset of hydrogen bonded collective network of water in 1,4-dioxane.

PubMed

Luong, Trung Quan; Verma, Pramod Kumar; Mitra, Rajib Kumar; Havenith, Martina

2011-12-22

We have studied the evolution of water hydrogen bonded collective network dynamics in mixtures of 1,4-dioxane (Dx) as the mole fraction of water (X(w)) increases from 0.005 to 0.54. The inter- and intramolecular vibrations of water have been observed using terahertz time domain spectroscopy (THz-TDS) in the frequency range 0.4-1.4 THz (13-47 cm(-1)) and Fourier transform infrared (FTIR) spectroscopy in the far-infrared (30-650 cm(-1)) and mid-infrared (3000-3700 cm(-1)) regions. These results have been correlated with the reactivity of water in these mixtures as determined by kinetic studies of the solvolysis reaction of benzoyl chloride (BzCl). Our studies show an onset of intermolecular hydrogen bonded water network dynamics beyond X(w) ≥ 0.1. At the same concentration, we observe a rapid increase of the rate constant of solvolysis of BzCl in water-Dx mixtures. Our results establish a correlation between the onset of collective hydrogen bonded network with the solvation dynamics and the activity of clustered water.

Inhibitors of human immunodeficiency virus type 1 (HIV-1) attachment. 5. An evolution from indole to azaindoles leading to the discovery of 1-(4-benzoylpiperazin-1-yl)-2-(4,7-dimethoxy-1H-pyrrolo[2,3-c]pyridin-3-yl)ethane-1,2-dione (BMS-488043), a drug candidate that demonstrates antiviral activity in HIV-1-infected subjects.

PubMed

Wang, Tao; Yin, Zhiwei; Zhang, Zhongxing; Bender, John A; Yang, Zhong; Johnson, Graham; Yang, Zheng; Zadjura, Lisa M; D'Arienzo, Celia J; DiGiugno Parker, Dawn; Gesenberg, Christophe; Yamanaka, Gregory A; Gong, Yi-Fei; Ho, Hsu-Tso; Fang, Hua; Zhou, Nannan; McAuliffe, Brian V; Eggers, Betsy J; Fan, Li; Nowicka-Sans, Beata; Dicker, Ira B; Gao, Qi; Colonno, Richard J; Lin, Pin-Fang; Meanwell, Nicholas A; Kadow, John F

2009-12-10

Azaindole derivatives derived from the screening lead 1-(4-benzoylpiperazin-1-yl)-2-(1H-indol-3-yl)ethane-1,2-dione (1) were prepared and characterized to assess their potential as inhibitors of HIV-1 attachment. Systematic replacement of each of the unfused carbon atoms in the phenyl ring of the indole moiety by a nitrogen atom provided four different azaindole derivatives that displayed a clear SAR for antiviral activity and all of which displayed marked improvements in pharmaceutical properties. Optimization of these azaindole leads resulted in the identification of two compounds that were advanced to clinical studies: (R)-1-(4-benzoyl-2-methylpiperazin-1-yl)-2-(4-methoxy-1H-pyrrolo[2,3-b]pyridin-3-yl)ethane-1,2-dione (BMS-377806, 3) and 1-(4-benzoylpiperazin-1-yl)-2-(4,7-dimethoxy-1H-pyrrolo[2,3-c]pyridin-3-yl)ethane-1,2-dione (BMS-488043, 4). In a preliminary clinical study, 4 administered as monotherapy for 8 days, reduced viremia in HIV-1-infected subjects, providing proof of concept for this mechanistic class.

Composition, Characterization and Antibacterial activity of Mn(II), Co(II),Ni(II), Cu(II) Zn(II) and Cd(II) mixed ligand complexes Schiff base derived from Trimethoprim with 8-Hydroxy quinoline

NASA Astrophysics Data System (ADS)

Numan, Ahmed T.; Atiyah, Eman M.; Al-Shemary, Rehab K.; Ulrazzaq, Sahira S. Abd

2018-05-01

New Schiff base ligand 2-((4-amino-5-(3, 4, 5-trimethoxybenzyl) pyrimidin-2-ylimino) (phenyl)methyl)benzoic acid] = [HL] was synthesized using microwave irradiation trimethoprim and 2-benzoyl benzoic acid. Mixed ligand complexes of Mn((II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) are reacted in ethanol with Schiff base ligand [HL] and 8-hydroxyquinoline [HQ] then reacted with metal salts in ethanol as a solvent in (1:1:1) ratio. The ligand [HL] is characterized by FTIR, UV-Vis, melting point, elemental microanalysis (C.H.N), 1H-NMR, 13C-NMR, and mass spectra. The mixed ligand complexes are characterized by infrared spectra, electronic spectra, (C.H.N), melting point, atomic absorption, molar conductance and magnetic moment measurements. These measurements indicate that the ligand [HL] coordinates with metal (II) ion in a tridentate manner through the oxygen and nitrogen atoms of the ligand, octahedral structures are suggested for these complexes. Antibacterial activity of the ligands [HL], [HQ] and their complexes are studied against (gram positive) and (gram negative) bacteria.

The benzylperoxyl radical as a source of hydroxyl and phenyl radicals.

PubMed

Sander, Wolfram; Roy, Saonli; Bravo-Rodriguez, Kenny; Grote, Dirk; Sanchez-Garcia, Elsa

2014-09-26

The benzyl radical (1) is a key intermediate in the combustion and tropospheric oxidation of toluene. Because of its relevance, the reaction of 1 with molecular oxygen was investigated by matrix-isolation IR and EPR spectroscopy as well as computational methods. The primary reaction product of 1 and O2 is the benzylperoxyl radical (2), which exists in several conformers that can easily interconvert even at cryogenic temperatures. Photolysis of radical 2 at 365 nm results in a formal [1,3]-H migration and subsequent cleavage of the O-O bond to produce a hydrogen-bonded complex between the hydroxyl radical and benzaldehyde (4). Prolonged photolysis produces the benzoyl radical (5) and water, which finally yield the phenyl radical (7), CO, and H2O. Thus, via a sequence of exothermic reactions 1 is transformed into radicals of even higher reactivity, such as OH and 7. Our results have implications for the development of models for the highly complicated process of combustion of aromatic compounds. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation and biocompatibility of crosslinked poly(3-hydroxyundecenoate).

PubMed

Chung, Chungwook; Chung, Kyudon; Kim, Do Young; Lee, Sun Hee; Kim, Jong-Sik; Rhee, Young Ha

2018-02-01

A sticky polymer, poly(3-hydroxyundecenoate) (PHU), was produced by Pseudomonas oleovorans when nonanoate and undecenoate were used as carbon sources. Crosslinked PHU (CL-PHU) was prepared by heating using benzoyl peroxide as a crosslinker. According to the degree of crosslinking in the polymer, three types of CL-PHU were prepared: CL-PHU50, CL-PHU60 and CL-PHU70. Fourier transform-infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry results suggested that crosslinking of PHU was successfully achieved by heat, which increased the crosslinking density and decreased stiffness and flexibility of the polymer. Water contact angle measurements revealed no differences of hydrophilicity as the crosslinking density. Slight morphological changes of CL-PHU film surfaces were observed by atomic force microscopy. Chinese hamster ovary cells were used to investigate the biocompatibility of CL-PHU films using poly(l-lactide) surfaces as control. Surface properties of the film, such as roughness and adhesive force, enhanced the adhesion and proliferation of cells on the films. CL-PHU might be useful for cell compatible biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Electrogenerated Chemiluminescence of BODIPY, Ru(bpy)32+, and 9,10-Diphenylanthracene Using Interdigitated Array Electrodes

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

Nepomnyashchii, Alexander B.; Kolesov, Grigory; Parkinson, Bruce A.

Interdigitated array electrodes (IDAs) were used to produce steady-state electrogenerated chemiluminescence (ECL) by annihilation of oxidized and reduced forms of a substituted boron dipyrromethene (BODIPY) dye, 9,10-diphenylanthracene (DPA), and ruthenium(II) tris(bypiridine) (Ru-(bpy)32+). Digital simulations were in good agreement with the experimentally obtained currents and light outputs. Coreactant experiments, using tri-n-propylamine and benzoyl peroxide as a sacrificial homogeneous reductant or oxidant, show currents corresponding to electrode reactions of the dyes and not the oxidation or reduction of the coreactants. The results show that interdigitated arrays can produce stable ECL where the light intensity is magnified due to the larger currents asmore » a consequence of feedback between generator and collector electrodes in the IDA. The light output for ECL is around 100 times higher than that obtained with regular planar electrodes with similar area. This material is based upon work supported as part of the Center of Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.« less

Hydrolytic Activation Kinetics of the Herbicide Benzobicyclon in Simulated Aquatic Systems.

PubMed

Williams, Katryn L; Tjeerdema, Ronald S

2016-06-22

Herbicide resistance is a growing concern for weeds in California rice fields. Benzobicyclon (BZB; 3-(2-chloro-4-(methylsulfonyl)benzoyl)-2-phenylthiobicyclo[3.2.1]oct-2-en-4-one) has proven successful against resistant rice field weeds in Asia. A pro-herbicide, BZB forms the active agent, benzobicyclon hydrolysate (BH), in water; however, the transformation kinetics are not understood for aquatic systems, particularly flooded California rice fields. A quantitative experiment was performed to assess the primary mechanism and kinetics of BZB hydrolysis to BH. Complete conversion to BH was observed for all treatments. Basic conditions (pH 9) enhanced the reaction, with half-lives ranging from 5 to 28 h. Dissolved organic carbon (DOC) hindered transformation, which is consistent with other base-catalyzed hydrolysis reactions. BH was relatively hydrolytically stable, with 18% maximum loss after 5 days. Results indicate BZB is an efficient pro-herbicide under aqueous conditions such as those of a California rice field, although application may be best suited for fields with recirculating tailwater systems.

Helodermatine, a kallikrein-like, hypotensive enzyme from the venom of Heloderma horridum horridum (Mexican beaded lizard)

PubMed Central

1986-01-01

We have purified and characterized the major N-benzoyl-L-arginine ethyl ester hydrolase from the venom of Heloderma horridum horridum. The enzyme belongs to the serine proteinase family, and its activity vs. peptide amide substrates and human high-molecular-weight kininogen suggests a similarity to the family of kallikreins. This interpretation is corroborated by its reactivity with the natural inhibitors soybean trypsin inhibitor and Kunitz-type bovine pancreatic trypsin inhibitor (aprotinin). Injection of the enzyme (2-16 micrograms/kg) into anesthetized rabbits leads to a rapid dose-dependent transient decrease of the arterial blood pressure. Like glandular kallikrein it specifically converts single-chain tissue type plasminogen activator into its double chain form. In contrast to other kallikrein-like enzymes from snake venoms it shows no thrombin-like or plasminogen activator activity. The enzyme is a single-chain glycoprotein (Mr 63,000). The N-terminal sequence revealed significant homology to pig pancreatic kallikrein and to kallikrein like enzymes from Crotalus atrox and Crotalus adamanteus venom. This enzyme, which we name Helodermatine, is the first purified from Sauria with kallikrein-like properties. PMID:3537191

Contact urticaria, allergic contact dermatitis, and photoallergic contact dermatitis from oxybenzone.

PubMed

Landers, Maeran; Law, Sandra; Storrs, Frances J

2003-03-01

There is little literature regarding conventional patch tests and photopatch tests to oxybenzone resulting in both immediate- and delayed-type hypersensitivity reactions. A patient was patch-tested and photopatch-tested to various sunscreen chemicals. Both immediate- and delayed-type hypersensitivity reactions were observed with oxybenzone. The positive patch tests were also photoaccentuated. Oxybenzone, a common sunscreen allergen, can result in both contact urticaria and delayed-type hypersensitivity on both conventional patch testing and photopatch testing. Allergic contact dermatitis to sunscreen chemicals has traditionally included contact urticaria, allergic contact dermatitis, and photoallergic contact dermatitis. Due to the recognition of p-aminobenzoic acid (PABA) and its esters as sensitizers, the presence of benzophenones in "PABA-free" sunscreens has become more prevalent, especially in sunscreens with a sun protection factor (SPF) greater than 8. In our patient, immediate- and delayed-type hypersensitivity reactions were seen to oxybenzone (2-hydroxy-4-methoxybenzophenone, 2-benzoyl-5-methoxyphenol, benzophenone-3, Eusolex 4360, Escalol 567, EUSORB 228, Spectra-Sorb UV-9, Uvinul M-40) upon conventional patch testing and photopatch testing.

Time-resolved polarization imaging by pump-probe (stimulated emission) fluorescence microscopy.

PubMed Central

Buehler, C; Dong, C Y; So, P T; French, T; Gratton, E

2000-01-01

We report the application of pump-probe fluorescence microscopy in time-resolved polarization imaging. We derived the equations governing the pump-probe stimulated emission process and characterized the pump and probe laser power levels for signal saturation. Our emphasis is to use this novel methodology to image polarization properties of fluorophores across entire cells. As a feasibility study, we imaged a 15-microm orange latex sphere and found that there is depolarization that is possibly due to energy transfer among fluorescent molecules inside the sphere. We also imaged a mouse fibroblast labeled with CellTracker Orange CMTMR (5-(and-6)-(((4-chloromethyl)benzoyl)amino)tetramethyl-rhodamine). We observed that Orange CMTMR complexed with gluthathione rotates fast, indicating the relatively low fluid-phase viscosity of the cytoplasmic microenvironment as seen by Orange CMTMR. The measured rotational correlation time ranged from approximately 30 to approximately 150 ps. This work demonstrates the effectiveness of stimulated emission measurements in acquiring high-resolution, time-resolved polarization information across the entire cell. PMID:10866979

Building blocks for the synthesis of glycosyl-myo-inositols involved in the insulin intracellular signalling process.

PubMed

Zapata, A; Martín-Lomas, M

1992-10-09

Glycosylation of (+/- )-1-O-benzyl-2,3:5,6-di-O-isopropylidene-myo-inositol (4) with 6-O-acetyl-4-O-allyl-2-azido-3-O-benzyl-2-deoxy-beta-D-glucopyranosyl trichloroacetimidate (6) gave the 4-O-(2-amino-2-deoxy-alpha-D-glucopyranosyl)- myo-inositol derivative (9) as a mixture of diastereoisomers which could be resolved by chromatography. Likewise alpha-glycosylation of 4 with 6-O-acetyl-2-azido-3-O-benzoyl-2-deoxy-4-O-(2,3,4,6-tetra-O-acetyl-beta- D- galactopyranosyl)-D-glucopyranosyl trichloroacetimidate (10) gave the corresponding pseudotrisaccharide derivative 16 as a mixture of diastereomers which could be resolved partially by chromatography. alpha-Glycosylation of enantiomerically pure 2,3:5,6- (18) and 2,3:4,5-di-O-isopropylidene-1-O-menthoxycarbonyl-myo-inositol (19) with 3,4,6-tri-O-acetyl-2-azido-2-deoxy-D-glucopyranosyl trichloroacetimidate (20) gave the pseudodisaccharide derivatives 21 and 22, respectively. Likewise, alpha-glycosylation of 18 with 10 afforded a pseudotrisaccharide derivative (23).

Determination of molecular weight distributions in native and pretreated wood.

PubMed

Leskinen, Timo; Kelley, Stephen S; Argyropoulos, Dimitris S

2015-03-30

The analysis of native wood components by size-exclusion chromatography (SEC) is challenging. Isolation, derivatization and solubilization of wood polymers is required prior to the analysis. The present approach allowed the determination of molecular weight distributions of the carbohydrates and of lignin in native and processed woods, without preparative component isolation steps. For the first time a component selective SEC analysis of sawdust preparations was made possible by the combination of two selective derivatization methods, namely; ionic liquid assisted benzoylation of the carbohydrate fraction and acetobromination of the lignin in acetic acid media. These were optimized for wood samples. The developed method was thus used to examine changes in softwood samples after degradative mechanical and/or chemical treatments, such as ball milling, steam explosion, green liquor pulping, and chemical oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The methodology can also be applied to examine changes in molecular weight and lignin-carbohydrate linkages that occur during wood-based biorefinery operations, such as pretreatments, and enzymatic saccharification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthesis and spectroscopic characterization of fluorescent 4-aminoantipyrine analogues: Molecular docking and in vitro cytotoxicity studies

NASA Astrophysics Data System (ADS)

Premnath, D.; Mosae Selvakumar, P.; Ravichandiran, P.; Tamil Selvan, G.; Indiraleka, M.; Jannet Vennila, J.

2016-01-01

Two substituted aromatic carbonyl compounds (compounds 1 and 2) of 4-aminoantipyrine were synthesized by condensation of fluorine substituted benzoyl chlorides and 4-aminoantipyrine. The structures of synthesized derivatives were established on the basis of UV-Vis, IR, and Mass, 1H, 13C NMR and Fluorescence spectroscopy. Both compounds showed significant fluorescence emission and two broad emission bands were observed in the region at 340 nm and 450 nm on excitation at 280 nm. Theoretically to prove that the molecule has anticancer activity against cervical cancer cells, the compounds were analyzed for molecular docking interactions with HPV16-E7 target protein by Glide protocol. Furthermore, 4-aminoantipyrine derivatives were evaluated for their in vitro cytotoxic activity against human cervical cancer cells (SiHa) by MTT assay. Compound 1 showed two fold higher activity (IC50 = 0.912 μM) over compound 2, and its activity was similar to that of Pazopanib, suggesting that although the two compounds were chemically very similar the difference in substituent on the phenyl moiety caused changes in properties.

Structural, thermogravimetric, B3LYP and biological studies on some heterocyclic thiosemicarbazide copper (II) complexes and evaluation of their molecular docking

NASA Astrophysics Data System (ADS)

Gaber, Mohamed; Fayed, Tarek A.; El-Gamil, Mohammed M.; Abu El-Reash, Gaber M.

2018-01-01

Two copper (II) complexes of ligands H2L1 and H2L2 have been prepared and investigated. The ligands were prepared by the individually addition of picolinic acid hydrazide and 2-(2-aminothiazol-4-yl) acetohydrazide into benzoyl isothiocyanate. The results of analytical and spectroscopic equipments revealed that H2L1 act as monobasic bidentate with square planner environment. While H2L2 behaves as monobasic tetradentate with Oh geometry. The geometries of ligands and their complexes being carefully studied using Jaguar 9.1 program based on the density functional theory (DFT) to predict properties of materials performed by the hybrid density functional method B3LYP. Additionally, thermal degradation data were evaluated to determine the kinetic and thermodynamic parameters by different methods. Moreover, the anti-oxidant (using DPPH and SOD methods), and anti-bacterial activities of the compounds have been studied. Furthermore, the docking study of ligands and their complexes were applied against gram-positive S. Aureus, negative E. Coli bacterial and C. Albicans fungal strains by Schrödinger suite program using XP glide protocol.

Determination of organic peroxides by liquid chromatography with on-line post-column ultraviolet irradiation and peroxyoxalate chemiluminescence detection.

PubMed

Wada, Mitsuhiro; Inoue, Keiyu; Thara, Ayuko; Kishikawa, Naoya; Nakashima, Kenichiro; Kuroda, Naotaka

2003-02-14

A HPLC method was developed for the simultaneous determination of organic peroxides and hydrogen peroxide with peroxyoxalate chemiluminescence (PO-CL) detection following on-line UV irradiation. Organic peroxides [i.e., benzoyl peroxide (BP), tert.-butyl hydroperoxide (BHP), tert.-butyl perbenzoate (BPB), cumene hydroperoxide (CHP)] were UV irradiated (254 nm, 15 W) to generate hydrogen peroxide, which was determined by PO-CL detection. The conditions for UV irradiation and PO-CL detection were optimized by a flow injection analysis (FIA) system. Generation of hydrogen peroxide from peroxides with on-line UV irradiation also was confirmed by the FIA system by incorporating an enzyme column reactor immobilized with catalase. The separation of four organic peroxides and hydrogen peroxide by HPLC was accomplished isocratically on an ODS column within 30 min. The detection limits (signal-to-noise ratio=3) were 1.1 microM for hydrogen peroxide, 6.8 microM for BP, 31.3 microM for BHP, 7.5 microM for BPB and 1.3 microM for CHP. The proposed method was applied to the determination of BP in wheat flour.

Trypsin from the pyloric caeca of bluefish (Pomatomus saltatrix).

PubMed

Klomklao, Sappasith; Benjakul, Soottawat; Visessanguan, Wonnop; Kishimura, Hideki; Simpson, Benjamin K

2007-12-01

Trypsin was purified from the pyloric caeca of bluefish (Pomatomus saltatrix) by ammonium sulfate precipitation, acetone precipitation and soybean trypsin inhibitor-Sepharose 4B affinity chromatography. Bluefish trypsin migrated as a single band using both sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and native-PAGE and had a molecular mass of 28 kDa. The optima pH and temperature for the hydrolysis of benzoyl-dl-arginine-p-nitroanilide (BAPNA) were 9.5 and 55 degrees C, respectively. The enzyme was stable over a broad pH range (7 to 12), but was unstable at acidic pH, and at temperatures greater than 40 degrees C. The enzyme was inhibited by specific trypsin inhibitors: soybean trypsin inhibitor (SBTI), N-p-tosyl-l-lysine chloromethyl ketone (TLCK) and the serine protease inhibitor phenylmethyl sulfonylfluoride (PMSF). CaCl2 partially protected trypsin against activity loss at 40 degrees C, but NaCl (0 to 30%) decreased the activity in a concentration dependent manner. The N-terminal amino acid sequence of trypsin was determined as IVGGYECKPKSAPVQVSLNL and was highly homologous to other known vertebrate trypsins.

Photoaffinity Labeling of Ras Converting Enzyme using Peptide Substrates that Incorporate Benzoylphenylalanine (Bpa) Residues: Improved Labeling and Structural Implications

PubMed Central

Kyro, Kelly; Manandhar, Surya P.; Mullen, Daniel; Schmidt, Walter K.; Distefano, Mark D.

2012-01-01

Rce1p catalyzes the proteolytic trimming of C-terminal tripeptides from isoprenylated proteins containing CAAX-box sequences. Because Rce1p processing is a necessary component in the Ras pathway of oncogenic signal transduction, Rce1p holds promise as a potential target for therapeutic intervention. However, its mechanism of proteolysis and active site have yet to be defined. Here, we describe synthetic peptide analogues that mimic the natural lipidated Rce1p substrate and incorporate photolabile groups for photoaffinity-labeling applications. These photoactive peptides are designed to crosslink to residues in or near the Rce1p active site. By incorporating the photoactive group via p-benzoyl-L-phenylalanine (Bpa) residues directly into the peptide substrate sequence, the labeling efficiency was substantially increased relative to a previously-synthesized compound. Incorporation of biotin on the N-terminus of the peptides permitted photolabeled Rce1p to be isolated via streptavidin affinity capture. Our findings further suggest that residues outside the CAAX-box sequence are in contact with Rce1p, which has implications for future inhibitor design. PMID:22079863

Benzoate Mediates Repression of C4-Dicarboxylate Utilization in “Aromatoleum aromaticum” EbN1

PubMed Central

Trautwein, Kathleen; Grundmann, Olav; Wöhlbrand, Lars; Eberlein, Christian; Boll, Matthias

2012-01-01

Diauxic growth was observed in anaerobic C4-dicarboxylate-adapted cells of “Aromatoleum aromaticum” EbN1 due to preferred benzoate utilization from a substrate mixture of a C4-dicarboxylate (succinate, fumarate, or malate) and benzoate. Differential protein profiles (two-dimensional difference gel electrophoresis [2D DIGE]) revealed dynamic changes in abundance for proteins involved in anaerobic benzoate catabolism and C4-dicarboxylate uptake. In the first active growth phase, benzoate utilization was paralleled by maximal abundance of proteins involved in anaerobic benzoate degradation (e.g., benzoyl-coenzyme A [CoA] reductase) and minimal abundance of DctP (EbA4158), the periplasmic binding protein of a predicted C4-dicarboxylate tripartite ATP-independent periplasmic (TRAP) transporter (DctPQM). The opposite was observed during subsequent succinate utilization in the second active growth phase. The increased dctP (respectively, dctPQM) transcript and DctP protein abundance following benzoate depletion suggests that repression of C4-dicarboxylate uptake seems to be a main determinant for the observed diauxie. PMID:22081395

Gateways to clinical trials.

PubMed

Tomillero, A; Moral, M A

2009-06-01

(+)-Dapoxetine hydrochloride; Abatacept, Adalimumab, Agalsidase beta, Alemtuzumab, Alglucosidase alfa, Aliskiren fumarate, Ambrisentan, Amlodipine, Aripiprazole, Atrasentan, Azacitidine, Azelnidipine; Belotecan hydrochloride, Bevacizumab, Bilastine, Biphasic insulin aspart, Bortezomib, Bosentan; Caspofungin acetate, CG-100649, Cinacalcet hydrochloride, Clindamycin phosphate/ benzoyl peroxide; Dasatinib, Denosumab, Duloxetine hydrochloride, Dutasteride, Dutasteride/tamsulosin; Ecogramostim, Eculizumab, Eltrombopag olamine, EndoTAG-1, Erlotinib hydrochloride, Everolimus, Exenatide, Ezetimibe; FAHF-2, Fondaparinux sodium; Gefitinib, Golimumab; HEV-239, HSV-TK; Imatinib mesylate, Indium 111 ((111)In) ibritumomab tiuxetan, Influenza vaccine(surface antigen, inactivated, prepared in cell culture), Insulin glargine; Kisspeptin-54; Lidocaine/prilocaine, Lomitapide; Maraviroc, Mirodenafil hydrochloride, MK-8141, MVA-Ag85A; Nilotinib hydrochloride monohydrate; Olmesartan medoxomil; Paclitaxel-eluting stent, Pegfilgrastim, Peginterferon alfa-2a, Peginterferon alfa-2b, Pemetrexed disodium, Pitavastatin calcium, Prasugrel; Recombinant human relaxin H2, RHAMM R3 peptide, Rivaroxaban, Rosuvastatin calcium, RRz2; Sagopilone, Salinosporamide A, SB-509, Serlopitant, Sirolimus-eluting stent, Sorafenib, Sunitinib malate; Tadalafil, Temsirolimus, Teriparatide, TG-4010, Tositumomab/iodine (I131) tositumomab; Velusetrag Hydrochloride; Ximelagatran; Yttrium 90 (90Y) ibritumomab tiuxetan. Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.

In Vitro Screening of Anti-lice Activity of Pongamia pinnata Leaves

PubMed Central

Radhamani, Suraj; Gopinath, Rejitha; Kalusalingam, Anandarajagopal; Vimala, Anita Gnana Kumari Anbumani; Husain, Hj Azman

2009-01-01

Growing patterns of pediculocidal drug resistance towards head louse laid the foundation for research in exploring novel anti-lice agents from medicinal plants. In the present study, various extracts of Pongamia pinnata leaves were tested against the head louse Pediculus humanus capitis. A filter paper diffusion method was conducted for determining the potential pediculocidal and ovicidal activity of chloroform, petroleum ether, methanol, and water extracts of P. pinnata leaves. The findings revealed that petroleum ether extracts possess excellent anti-lice activity with values ranging between 50.3% and 100% where as chloroform and methanol extracts showed moderate pediculocidal effects. The chloroform and methanol extracts were also successful in inhibiting nymph emergence and the petroleum ether extract was the most effective with a complete inhibition of emergence. Water extract was devoid of both pediculocidal and ovicidal activities. All the results were well comparable with benzoyl benzoate (25% w/v). These results showed the prospect of using P. pinnata leave extracts against P. humanus capitis in difficult situations of emergence of resistance to synthetic anti-lice agents. PMID:19967085

Organocatalytic aza-Michael/retro-aza-Michael reaction: pronounced chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction.

PubMed

Cai, Yong-Feng; Li, Li; Luo, Meng-Xian; Yang, Ke-Fang; Lai, Guo-Qiao; Jiang, Jian-Xiong; Xu, Li-Wen

2011-05-01

A detailed experimental investigation of an aza-Michael reaction of aniline and chalcone is presented. A series of Cinchona alkaloid-derived organocatalysts with different functional groups were prepared and used in the aza-Michael and retro-aza-Michael reaction. There was an interesting finding that a complete reversal of stereoselectivity when a benzoyl group was introduced to the cinchonine and cinchonidine. The chirality amplification vs. time proceeds in the quinine-derived organocatalyst containing silicon-based bulky group, QN-TBS, -catalyzed aza-Michael reaction under solvent-free conditions. In addition, we have demonstrated for the first time that racemization was occurred in suitable solvents under mild conditions due to retro-aza-Michael reaction of the Michael adduct of aniline with chalcone. These indicate the equilibrium of retro-aza-Michael reaction and aza-Michael reaction produce the happening of chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction under different conditions, which would be beneficial to the development of novel chiral catalysts for the aza-Michael reactions. Copyright © 2011 Wiley-Liss, Inc.

Crystal structure characterization as well as theoretical study of spectroscopic properties of novel Schiff bases containing pyrazole group.

PubMed

Guo, Jia; Ren, Tiegang; Zhang, Jinglai; Li, Guihui; Li, Weijie; Yang, Lirong

2012-09-01

A series of novel Schiff bases containing pyrazole group were synthesized using 1-aryl-3-methyl-4-benzoyl-5-pyrazolone and phenylenediamine as the starting materials. All as-synthesized Schiff bases were characterized by means of NMR, FT-IR, and MS; and the molecular geometries of two Schiff bases as typical examples were determined by means of single crystal X-ray diffraction. In the meantime, the ultraviolet-visible light absorption spectra and fluorescent spectra of various as-synthesized products were also measured. Moreover, the B3LYP/6-1G(d,p) method was used for the optimization of the ground state geometry of the Schiff bases; and the spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVTZ basis set of TD-B3LYP method. It has been found that all as-synthesized Schiff bases show a remarkable absorption peak in a wavelength range of 270-370 nm; and their maximum emission peaks are around 344 nm and 332 nm, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

Evaluation of certain food additives and contaminants.

PubMed

2001-01-01

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives and contaminants, with a view to recommending Acceptable Daily Intakes (ADIs) and tolerable intakes, respectively, and to prepare specifications for the identity and purity of food additives. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of food additives and contaminants (including flavouring agents), and the establishment and revision of specifications. A summary follows of the Committee's evaluations of toxicological data on various specific food additives (furfural, paprika oleoresin, caramel colour II, cochineal extract, carmines, aspartame-acesulfame salt, D-tagatose, benzoyl peroxide, nitrous oxide, stearyl tartrate and trehalose), flavouring agents and contaminants (cadmium and tin), and of intake data on calcium from calcium salts of food additives. Annexed to the report are tables summarizing the Committee's recommendations for ADIs of the food additives and tolerable intakes of the contaminants considered, changes in the status of specifications of these food additives and specific flavouring agents, and further information required or desired.

Analysis of ligand-receptor cross-linked fragments by mass spectrometry

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

Son, C.D.; Sargsyan, H.; Hurst, Gregory

G-protein coupled receptors (GPCRs) are a class of integral membrane receptor proteins that are characterized by a signature seven-transmembrane (7-TM) configuration. The a-factor receptor (Ste2p) from Saccharomyces cerevisiae is a GPCR that, upon binding of a peptide ligand, transduces a signal to initiate a cascade of events leading to the mating of haploid yeast cells. This study summarizes the application of affinity purification and of matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) experiments using biotinylated photoactivatable a-factor analogs. Affinity purification and enrichment of biotinylated peptides by monomeric avidin beads resulted in mass spectrometric detection of specific signals corresponding to crosslinked fragments ofmore » Ste2p. Data obtained from cyanogen bromide (CNBr) fragments of receptor cross-linked to an a-factor analog with the photoaffinity group p-benzoyl-L-phenylalanine on position 1 were in agreement with the previous results reported by our laboratory suggesting the cross-linking between position 1 of a-factor and a region of Ste2p covering residues 251 294.« less

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.

[Simultaneous determination of sugar alcohols and sugars in functional foods by precolumn ultraviolet derivatization--high performance liquid chromatography].

PubMed

Liu, Ya-Pan; Ran, Xue-Qin; Chen, Lu-Ying; Zhang, Jing; Ruan, Jia; Li, Yong-Xin; Sun, Chengjun

2014-09-01

To establish a method using precolumn ultraviolet derivatization coupled with high performance liquid chromatography (HPLC) for simultaneous determination of erythritol, xylitol, galactitol, sorbitol, mannitol, maltitol, glucose and sucrose in functional foods. Target sugar alcohols and sugars in food samples were extracted in water by ultrasonic method and then reacted with benzoyl chloride to form violet-absorbing products, which were separated on a C18 column with gradient elution using methanol and water as mobile phase. The experiment was performed using a flow rate of 1.00 mL/min, column temperature at 30 degrees C and detected wavelength at 232 nm. The linear correlation coefficients of all the derivatives were more than 0. 999. The detection limits of the method were as low as 2. 2 microg/mL. The average recoveries were 89.6%-117.0%, with intraday relative standard derivations lower than 5%. This method is simple, inexpensive and easy to operate and it is suitable for the determination of sugar alcohols and glucose and sucrose in functional foods.

Determination of ideal-gas enthalpies of formation for key compounds:

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

Steele, W.V.; Chirico, R.D.; Nguyen, A.

1991-10-01

The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Ideal-gas enthalpies of formation of ({plus minus})-butan-2-ol, tetradecan-1-ol, hexan-1,6-diol, methacrylamide, benzoyl formic acid, naphthalene-2,6-dicarboxylic acid dimethyl ester, and tetraethylsilane are reported. A crystalline-phase enthalpy of formation at 298.15 K was determined for naphthalene-2,6-dicarboxylic acid, which decomposed at 695 Kmore » before melting. The combustion calorimetry of tetraethylsilane used the proven fluorine-additivity methodology. Critical temperature and critical density were determined for tetraethylsilane with differential scanning calorimeter and the critical pressure was derived. Group-additivity parameters useful in the application of group- contribution correlations are derived. 112 refs., 13 figs., 19 tabs.« less

A diffuse reflectance comparative study of benzil inclusion within microcrystalline cellulose and beta-cyclodextrin.

PubMed

Vieira Ferreira, Luis F; Ferreira Machado, Isabel; Da Silva, José P; Oliveira, Anabela S

2004-02-01

Diffuse reflectance and laser-induced techniques were used to study photochemical and photophysical processes of benzil adsorbed on two solid powdered supports, microcrystalline cellulose and [small beta]-cyclodextrin. In both substrates, a distribution of ground-state benzil conformers exists, largely dominated by skew conformations where the carbonyl groups are twisted one to the other. Room temperature phosphorescence was observed in air-equilibrated samples in both cases. The decay times vary greatly and the largest lifetime was obtained for benzil/[small beta]-cyclodextrin, showing that this host's cavity accommodates benzil well, enhancing its room temperature phosphorescence. Triplet-triplet absorption of benzil entrapped in cellulose was detected and benzil ketyl radical formation also occurred. With benzil included into [small beta]-cyclodextrin, and following laser excitation, benzoyl radicals were detected on the millisecond timescale. Product analysis and identification of laser-irradiated benzil samples in the two hosts clearly showed that the main degradation photoproducts were benzoic acid and benzaldehyde. The main differences were a larger benzoic acid/benzaldehyde ratio in the case of cellulose and the formation of benzyl alcohol in this support.

A Versatile Molecular Design for High-Performance Nondoped OLEDs with ~100% Exciton Utilization and Negligible Efficiency Roll-Off.

PubMed

Liu, Huijun; Zeng, Jiajie; Guo, Jingjing; Nie, Han; Zhao, Zujin; Tang, Ben Zhong

2018-06-01

Nondoped organic light-emitting diodes (OLEDs) possess merits of higher stability and easier fabrication than doped devices. However, luminescent materials with high exciton utilization are generally unsuitable for nondoped OLEDs because of severe emission quenching and exciton annihilation in neat films. Herein, we wish to report a novel molecular design of integrating aggregation-induced delayed fluorescence (AIDF) moiety within host materials to explore efficient luminogens for nondoped OLEDs. By grafting 4-(phenoxazin-10-yl)benzoyl to common host materials, we develop a series of new luminescent materials with prominent AIDF property. Their neat films fluoresce strongly and can fully harvest both singlet and triplet excitons with suppressed exciton annihilation. Nondoped OLEDs of these AIDF luminogens exhibit excellent luminance (~100000 cd m-2), outstanding external quantum efficiencies (22.1-22.6%), negligible efficiency roll-off and improved operational stability. To the best of our knowledge, these are the most efficient nondoped OLEDs reported so far. This convenient and versatile molecular design is of high significance for the advance of nondoped OLEDs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibition of HIF-1{alpha} activity by BP-1 ameliorates adjuvant induced arthritis in rats

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

Shankar, J.; Thippegowda, P.B., E-mail: btprabha@uic.edu; Kanum, S.A.

Rheumatoid arthritis (RA) is a chronic inflammatory, angiogenic disease. Inflamed synovitis is a hallmark of RA which is hypoxic in nature. Vascular endothelial growth factor (VEGF), one of the key regulators of angiogenesis, is overexpressed in the pathogenesis of RA. VEGF expression is regulated by hypoxia-inducible factor-1{alpha} (HIF-1{alpha}), a master regulator of homeostasis which plays a pivotal role in hypoxia-induced angiogenesis. In this study we show that synthetic benzophenone analogue, 2-benzoyl-phenoxy acetamide (BP-1) can act as a novel anti-arthritic agent in an experimental adjuvant induced arthritis (AIA) rat model by targeting VEGF and HIF-1{alpha}. BP-1 administered hypoxic endothelial cells andmore » arthritic animals clearly showed down regulation of VEGF expression. Further, BP-1 inhibits nuclear translocation of HIF-1{alpha}, which in turn suppresses transcription of the VEGF gene. These results suggest a further possible clinical application of the BP-1 derivative as an anti-arthritic agent in association with conventional chemotherapeutic agents.« less

CXCR4 engagement promotes dendritic cell survival and maturation

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

Kabashima, Kenji; Sugita, Kazunari; Shiraishi, Noriko

2007-10-05

It has been reported that human monocyte derived-dendritic cells (DCs) express CXCR4, responsible for chemotaxis to CXCL12. However, it remains unknown whether CXCR4 is involved in other functions of DCs. Initially, we found that CXCR4 was expressed on bone marrow-derived DCs (BMDCs). The addition of specific CXCR4 antagonist, 4-F-Benzoyl-TN14003, to the culture of mouse BMDCs decreased their number, especially the mature subset of them. The similar effect was found on the number of Langerhans cells (LCs) but not keratinocytes among epidermal cell suspensions. Since LCs are incapable of proliferating in vitro, these results indicate that CXCR4 engagement is important formore » not only maturation but also survival of DCs. Consistently, the dinitrobenzene sulfonic acid-induced, antigen-specific in vitro proliferation of previously sensitized lymph node cells was enhanced by CXCL12, and suppressed by CXCR4 antagonist. These findings suggest that CXCL12-CXCR4 engagement enhances DC maturation and survival to initiate acquired immune response.« less

Synthesis of 2,3-trans-3,4-cis- and 2,3-trans-3,4-trans-2,3,4-triphenyltetrahydrofurans.

PubMed

Munshi, K L; Dikshit, D K; Kapil, R S; Anand, N

1974-04-01

The synthesis of 2,3-trans-3,4-cis- and 2,3-trans-3,4-trans-2,3,4-triphenyltetrahydrofurans was undertaken because these compounds incorportae the essential structural features of certain 2,3-diphenyl-benzofurans and 1,2,3-triphenylalkanones reported earlier to have marked antifertility activity. The synthesis of the 2 tetrahydrofurans was achieved by the cyclization of corresponding 2,3,4-triphenylbutane-1,4-diols upon heating with dimethyl sulfoxide (DMSO). The butane 1,4-diols were in turn prepared either by direct litium aluminum hydride (LAH) reduction of methyl 3-benzoyl-2,3-diphenylpropionates or by conversion of these propionates to delta-3,4-butryrolactones followed by LAH reduction. The propionates were prepared from the Fiedel-Crafts reaction of 2,3-diphenylsuccinic anhydride with benzene. Tetrahydrofurans were tested for their antiimplantation activity in rats. 2,3-trans-3,4-cis-2,4-diphenyl-3-p -(beta-pyrrolidinoethoxy) phenyltetrahydrofuran oxalate was found to inhibit implantation completely at 50 mg/kg, but was inefective at a lower dose.

Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

PubMed Central

Moszner, Norbert; Lukáč, Ivan

2012-01-01

Summary (±)-10-Methacryloyloxycamphorquinone (MCQ) was synthesized from (±)-10-camphorsulfonic acid either by a known seven-step synthetic route or by a novel, shorter five-step synthetic route. MCQ was copolymerized with styrene (S) and the photochemical behavior of the copolymer MCQ/S was compared with that of a formerly studied copolymer of styrene with monomers containing the benzil (BZ) moiety (another 1,2-dicarbonyl). Irradiation (λ > 380 nm) of aerated films of styrene copolymers with monomers containing the BZ moiety leads to the insertion of two oxygen atoms between the carbonyl groups of BZ and to the formation of benzoyl peroxide (BP) as pendant groups on the polymer backbone. An equivalent irradiation of MCQ/S led mainly to the insertion of only one oxygen atom between the carbonyl groups of camphorquinone (CQ) and to the formation of camphoric anhydride (11) covalently bound to the polymer backbone. While the decomposition of pendant BP groups formed in irradiated films of styrene copolymers with pendant BZ groups leads to crosslinking, only small molecular-weight changes in irradiated MCQ/S were observed. PMID:22509202

Stimuli-responsive one-dimensional copolymer nanostructures fabricated by metallogel template polymerization and their adsorption of aspirin.

PubMed

Wen, Xing; Tang, Liming; Qiang, Lu

2014-06-14

pH responsive poly(N,N'-methylenebisacrylamide-co-4-vinylpyridine) (P(MBA-4VP)) one dimensional (1D) nanostructures have been prepared by metallogel template copolymerization, which was carried out in an Ag(i)-coordinated organogel with benzoyl peroxide (BPO) as the initiator. The product has been characterized using infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. The experimental results reveal that the gel fiber is a crucial template for polymerization. Due to the degradation of the template in copolymerization, nanofibers of metallogel were transcribed to copolymer nanowires. The introduction of co-monomer 4-vinylpyridine (4VP) imparts to the 1D copolymer nanostructures pH sensitivity and the possible use as an adsorption material of aspirin. Adsorbed 1D copolymer nanostructures could be regenerated using proton solvent, acid medium and salt solution. In addition, silver nanoparticle loaded copolymer nanowires have been produced from the reduction of silver ions instead of template removal, where silver ions act both as the template and as the nanoparticle growth substrate.

Evaluation of superporous hydrogel (SPH) and SPH composite in porcine intestine ex-vivo: assessment of drug transport, morphology effect, and mechanical fixation to intestinal wall.

PubMed

Dorkoosh, Farid A; Borchard, Gerrit; Rafiee-Tehrani, Morteza; Verhoef, J Coos; Junginger, Hans E

2002-03-01

The objective of this study was to investigate the potential of superporous hydrogel (SPH) and SPH composite (SPHC) polymers to enhance the transport of N-alpha-benzoyl-L-arginine ethylester (BAEE) and fluorescein isothiocyanate-dextran 4400 (FD4) across porcine intestinal epithelium ex-vivo, and to study any possible morphological damage to the epithelium by applying these polymers. In addition, the ability of these polymers to attach to the gut wall by mechanical pressure was examined by using a specifically designed centrifuge model. The transport of BAEE and FD4 across the intestinal mucosa was enhanced 2- to 3-fold by applying SPHC polymer in comparison to negative control. No significant morphological damage was observed by applying these polymers inside the intestinal lumen. Moreover, the SPH and SPHC polymers were able to attach mechanically to the intestinal wall by swelling and did not move in the intestinal lumen even when a horizontal force of 13 gms(-2) was applied. In conclusion, these polymers are appropriate vehicles for enhancing the intestinal absorption of peptide and protein drugs.

Fluorescence behaviour of 5,10-methenyltetrahydrofolate, 10-formyltetrahydrofolate, 10-formyldihydrofolate, and 10-formylfolate in aqueous solution at pH 8

NASA Astrophysics Data System (ADS)

Tyagi, A.; Penzkofer, A.; Batschauer, A.; Wolf, E.

2009-06-01

The fluorescence spectroscopic behaviour of (6R,S)-5,10-methenyltetrahydrofolate (MTHF), (6R,S)-10-formyltetrahydrofolate (10-HCO-H4folate), 10-formyldihydrofolate (10-HCO-H2folate), and 10-formylfolate (10-HCO-folate) in aqueous Tris-HCl buffer at pH 8 is studied. MTHF and 10-HCO-folate were commercially available. 10-HCO-H4folate was prepared from MTHF by hydrolysis at room temperature under anaerobic conditions. 10-HCO-H2folate was prepared by oxidation of 10-HCO-H4folate under aerobic conditions. Fluorescence quantum distributions at room temperature and fluorescence signal decays at room temperature and liquid nitrogen temperature were measured. The fluorescence lifetimes determined at room temperature (liquid nitrogen temperature) are 10 ps (2.9 ns) for MTHF, 38 ps (3.7 ns) for 10-HCO-H4folate, 80 ps (10.5 ns) for 10-HCO-H2folate, and 7.1 ns (20 ns) for 10-HCO-folate. The results are discussed in terms of dyadic (pterin-benzoyl-glutamate) photo-induced electron transfer and dyadic fluorescent dynamics.

Separation/preconcentration and determination of vanadium with dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) and electrothermal atomic absorption spectrometry.

PubMed

Asadollahi, Tahereh; Dadfarnia, Shayessteh; Shabani, Ali Mohammad Haji

2010-06-30

A novel dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) for separation/preconcentration of ultra trace amount of vanadium and its determination with the electrothermal atomic absorption spectrometry (ETAAS) was developed. The DLLME-SFO behavior of vanadium (V) using N-benzoyl-N-phenylhydroxylamine (BPHA) as complexing agent was systematically investigated. The factors influencing the complex formation and extraction by DLLME-SFO method were optimized. Under the optimized conditions: 100 microL, 200 microL and 25 mL of extraction solvent (1-undecanol), disperser solvent (acetone) and sample volume, respectively, an enrichment factor of 184, a detection limit (based on 3S(b)/m) of 7 ng L(-1) and a relative standard deviation of 4.6% (at 500 ng L(-1)) were obtained. The calibration graph using the preconcentration system for vanadium was linear from 20 to 1000 ng L(-1) with a correlation coefficient of 0.9996. The method was successfully applied for the determination of vanadium in water and parsley. Copyright 2010 Elsevier B.V. All rights reserved.

Redox-Active Star Molecules Incorporating the 4-Benzoylpyridinium Cation - Implications for the Charge Transfer Along Branches vs. Across the Perimeter in Dendrimer

NASA Technical Reports Server (NTRS)

Leventis, Nicholas; Yang, Jinua; Fabrizio,Even F.; Rawashdeh, Abdel-Monem M.; Oh, Woon Su; Sotiriou-Leventis, Chariklia

2004-01-01

Dendrimers are self-repeating globular branched star molecules, whose fractal structure continues to fascinate, challenge, and inspire. Functional dendrimers may incorporate redox centers, and potential applications include antennae molecules for light harvesting, sensors, mediators, and artificial biomolecules. We report the synthesis and redox properties of four star systems incorporating the 4-benzoyl-N-alkylpyridinium cation; the redox potential varies along the branches but remains constant at fixed radii. Bulk electrolysis shows that at a semi-infinite time scale all redox centers are electrochemically accessible. However, voltammetric analysis (cyclic voltammetry and differential pulse voltammetry) shows that on1y two of the three redox-active centers in the perimeter are electrochemically accessible during potential sweeps as slow as 20 mV/s and as fast as 10 V/s. On the contrary, both redox centers along branches are accessible electrochemically within the same time frame. These results are explained in terms of slow through-space charge transfer and the globular 3-D folding of the molecules and are discussed in terms of their implications on the design of efficient redox functional dendrimers.

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

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua, E-mail: songhuihua@mail.hebtu.edu.cn

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H{sub 2}bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H{sub 2}O)]{sub n} (1), [Cd(bzgluO)(2,4′-bipy){sub 2}(H{sub 2}O)·3H{sub 2}O]{sub n} (2), [Cd(bzgluO)(phen)·H{sub 2}O]{sub n} (3), [Cd(bzgluO)(4,4′-bipy)(H{sub 2}O)]{sub n} (4), [Cd(bzgluO)(bpp)(H{sub 2}O)·2H{sub 2}O]{sub n} (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboringmore » layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H{sub 2}bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H{sub 2}bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H{sub 2}bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl

Tris[dimethyl (benzoyl­amido)­phosphato-κ2 O,O′](1,10-phenanthroline-κ2 N,N′)neodymium(III)

PubMed Central

Kariaka, Nataliia S.; Trush, Victor A.; Medviediev, Volodymyr V.; Sliva, Tetyana Yu.; Amirkhanov, Vladimir M.

2013-01-01

In both independent mol­ecules of the title compound, [Nd(C9H11NO4P)3(C12H8N2)], the NdIII atom is coordinated by six O atoms belonging to three phosphoryl ligands and two N atoms of 1,10-phenanthroline in a dodeca­hedral geometry. In the phosphoryl ligands, the benzene rings are twisted with respect to the planes of the sp 2-hybridized C atoms of the chelate rings by 12.1 (1)–24.7 (1)°. PMID:23476491

Comparative Mg(2+)-dependent sequential covalent binding stoichiometries of 3'-O-(4-benzoyl)benzoyl adenosine 5'-diphosphate of MF1, TF1, and the alpha 3 beta 3 core complex of TF1. The binding change motif is independent of the F1 gamma delta epsilon subunits.

PubMed

Aloise, P; Kagawa, Y; Coleman, P S

1991-06-05

Three F1 preparations, the beef heart (MF1) and thermophilic bacterium (TF1) holoenzymes, and the alpha 3 beta 3 "core" complex of TF1 reconstituted from individually expressed alpha and beta subunits, were compared as to their kinetic and binding stoichiometric responses to covalent photoaffinity labeling with BzATP and BzADP (+/- Mg2+). Each enzyme displayed an enhanced pseudo-first order rate of photoinhibition and one-third of the sites covalent binding to a catalytic site for full inhibition, plus, but not minus Mg2+. Titration of near stoichiometric [MgBzADP]/[F1] ratios during photolysis disclosed two sequential covalent binding patterns for each enzyme; a high affinity binding corresponding to unistoichiometric covalent association concomitant with enzyme inhibition, followed by a low affinity multisite-saturating covalent association. Thus, in the absence of the structural asymmetry inducing gamma delta epsilon subunits of the holoenzyme, the sequential binding of nucleotide at putative catalytic sites on the alpha 3 beta 3 complex of any F1 appears sufficient to effect binding affinity changes. With MF1, final covalent saturation of BzADP-accessible sites was achieved with 2 mol of BzADP/mol of enzyme, but with TF1 or its alpha 3 beta 3 complex, saturation required 3 mol of BzADP/mol of enzyme. Such differential final labeling stoichiometries could arise because of the endogenous presence of 1 nucleotide already bound to one of the 3 potential catalytic sites on normally prepared MF1, whereas TF1, possessing no endogenous nucleotide, has 3 vacant BzADP-accessible sites. Kinetics measurements revealed that regardless of the incremental extent of inhibition of the TF1 holoenzyme by BzADP during photolysis, the two higher apparent Km values (approximately 1.5 x 10(-4) and approximately 10(-3) M, respectively) of the progressively inactivated incubation are unchanged relative to fully unmodified enzyme. As reported for BzATP (or BzADP) and MF1 (Ackerman, S.H., Grubmeyer, C., and Coleman, P.S. (1987) J. Biol. Chem. 262, 13765-13772), this supports the fact that the photocovalent inhibition of F1 is a one-hit one-kill phenomenon. Isoelectric focusing gels revealed that [3H]BzADP covalently modifies both TF1 and MF1 exclusively on the beta subunit, whether or not Mg2+ is present. A single 19-residue [3H]BzADP-labeled peptide was resolved from a tryptic digest of MF1, and this peptide corresponded with the one believed to contain at least a portion of the beta subunit catalytic site domain (i.e. beta Ala-338----beta Arg-356).

Effects of (monomer - crosslinker – initiator) composition during non imprinted polymers synthesis for catechin retention

NASA Astrophysics Data System (ADS)

Triadhi, U.; Zulfikar, M. A.; Setiyanto, H.; Amran, M. B.

2018-05-01

MISPE (molecularly imprinted Solid Phase Extraction) is a separation technique using a solid adsorbent as a principle of MI (molecularly imprinted). Methacrylic acid (MAA) was used as a monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, benzoyl peroxide (BPO) as an initiator and acetonitrile (ACN) as a porogen. Catechin will be used as the template. Thermal and microwave methods were employed in the synthesis method. When analyzed using FTIR spectra, it was found that there were no significant differences between NIP (non-imprinted polymer) resulting from thermal method and that resulting from microwave method. Preparation of polymers by microwave method required 4 mins at 60-65 °C, significantly less than thermal method, that took 60 minutes at the same temperature. The variations of mole ratios of the monomer, the crosslinker, and the initiator were also performed. Based on the FTIR spectra, intensity of some peaks were changed due to the decreases of concentration. The optimum composition for NIP synthesis was MAA: EGDMA: BPO ratio of 5:30:0.5 (in mmole). The TGA curve showed that the NIP sythesized using microwave method experienced mass loss of around 98.50% at 604.8 °C.

Production and separation of (186g)Re from proton bombardment of (186)WC.

PubMed

Richards, Vernal N; Rath, Nigam; Lapi, Suzanne E

2015-06-01

A proof of concept study was undertaken where non-carrier added (186 g)Re was produced from the cyclotron bombardment of (186)WC. (186)WC was carbo-thermally generated from a novel precursor synthesized from (186)WO3, aqueous ammonia and hexamethyltetramine. The inherent high electrical and thermal conductivity of this material, coupled with its high melting point, made it an ideal candidate for proton bombardment for production of (186)Re. An18 μA irradiation for 3h and processing via thermo-chromatography, (186)WC yielded 0.93 mCi of (186 g)Re which corresponds to 89% of the calculated theoretical yields. The radiochemical purity of the desired (186 g)Re species was found to be between 95 and 97% with small contaminants of (186)ReO2. The radiochemistry utility of the product was investigated using S-benzoyl-MAG3, and 100% complexation was achieved with stability being maintained for 96 h. The re-oxidation of (186)WC back to(186)WO3 by oxygen in the thermo-chromatography method of processing ensured that the starting material was regenerated and recovered from the process in 94-98% yield. Copyright © 2015 Elsevier Inc. All rights reserved.

Bioconjugate functionalization of thermally carbonized porous silicon using a radical coupling reaction†

PubMed Central

Sciacca, Beniamino; Alvarez, Sara D.; Geobaldo, Francesco; Sailor, Michael J.

2011-01-01

The high stability of Salonen’s thermally carbonized porous silicon (TCPSi) has attracted attention for environmental and biochemical sensing applications, where corrosion-induced zero point drift of porous silicon-based sensor elements has historically been a significant problem. Prepared by the high temperature reaction of porous silicon with acetylene gas, the stability of this silicon carbide-like material also poses a challenge—many sensor applications require a functionalized surface, and the low reactivity of TCPSi has limited the ability to chemically modify its surface. This work presents a simple reaction to modify the surface of TCPSi with an alkyl carboxylate. The method involves radical coupling of a dicarboxylic acid (sebacic acid) to the TCPSi surface using a benzoyl peroxide initiator. The grafted carboxylic acid species provides a route for bioconjugate chemical modification, demonstrated in this work by coupling propylamine to the surface carboxylic acid group through the intermediacy of pentafluorophenol and 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC). The stability of the carbonized porous Si surface, both before and after chemical modification, is tested in phosphate buffered saline solution and found to be superior to either hydrosilylated (with undecylenic acid) or thermally oxidized porous Si surfaces. PMID:20967329

Grafting of steroids to hyaluronan towards the design of delivery systems for antioxidants: The role of hydrophobic core.

PubMed

Huerta-Ángeles, Gloria; Brandejsová, Martina; Novotný, Jaroslav; Kopecká, Kateřina; Šógorková, Jana; Šmejkalová, Daniela; Velebný, Vladimír

2018-08-01

In this work, amphiphilic hyaluronic acid (HA) was synthesized by the chemical bonding of steroids. Particularly, succinyl cholesterol (SCH), cholic acid (CA), deoxycholic acid (DOCA), and 18β-glycyrrhetinic acid (GA) were activated by benzoyl chloride towards the esterification reaction of HA in water. The degree of substitution can be controlled by varying the feed ratio of mixed anhydride to HA and up to 25% (mol/mol) can be obtained. Due to mild reaction conditions, no degradation of the polysaccharide was observed. The prepared amphiphilic polymers were characterized by NMR, infrared spectroscopy (FT-IR) and SEC/MALLS, as well as turbidity and size of the aggregates. The developed system is proposed for the delivery of hydrophobic drugs; for this purpose, curcumin, vitamin E and coenzyme Q10 were used as hydrophobic models; these molecules were loaded into the conjugates with high efficiency. The loading capacity was a function of degree of substitution. Furthermore, the biocompatibility of the derivatives and the cellular uptake of the delivery system enabled us to demonstrate the potential of the prepared delivery systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthesis of substituted 2-(β-D-glucopyranosyl)-benzimidazoles and their evaluation as inhibitors of glycogen phosphorylase.

PubMed

Bokor, Éva; Szilágyi, Enikő; Docsa, Tibor; Gergely, Pál; Somsák, László

2013-11-15

Microwave assisted condensation of O-perbenzoylated C-(β-d-glucopyranosyl)formic acid with 1,2-diaminobenzenes in the presence of triphenylphosphite gave the corresponding O-protected 2-(β-d-glucopyranosyl)-benzimidazoles in moderate yields. O-Perbenzoylated C-(β-d-glucopyranosyl)formamide and -thioformamide were transformed into the corresponding ethyl C-(β-d-glucopyranosyl)formimidate and -thioformimidate, respectively, by Et3O·BF4. Treatment of the formimidate with 1,2-diaminobenzenes afforded O-protected 2-(β-d-glucopyranosyl)-benzimidazoles in good to excellent yields. Similar reaction of the thioformimidate gave these compounds in lower yields. The O-benzoyl protecting groups were removed by the Zemplén protocol. These test compounds were assayed against rabbit muscle glycogen phosphorylase (GP) b, the prototype of liver GP, the rate limiting enzyme of glycogen degradation. The best inhibitors were 2-(β-d-glucopyranosyl)-4-methyl-benzimidazole (Ki=2.8μM) and 2-(β-d-glucopyranosyl)-naphtho[2,3-d]imidazole (Ki=2.1μM) exhibiting a ∼3-4 times stronger binding than the unsubstituted parent compound. Copyright © 2013 Elsevier Ltd. All rights reserved.

DNA-directed trypsin immobilization on a polyamidoamine dendrimer-modified capillary to form a renewable immobilized enzyme microreactor.

PubMed

Wu, Nan; Wang, Siming; Yang, Ye; Song, Jiayi; Su, Ping; Yang, Yi

2018-07-01

A novel type of trypsin capillary microreactor was developed based on a DNA-directed immobilization (DDI) technique applied to a fused-silica capillary modified with polyamidoamine (PAMAM) dendrimers. Trypsin binding to the inner wall of the capillary was confirmed by confocal laser scanning microscopy. The properties of the trypsin-DNA conjugated, PAMAM-modified capillary microreactor were investigated by monitoring hydrolysis of Nα-benzoyl- L -arginine ethyl ester. Through the hybridization and dehybridization of the DNA, the inner wall of the capillary functionalized with trypsin can be regenerated, thus indicating the renewability of this enzyme microreactor. In addition, these results demonstrated that introduction of PAMAM enabled higher amounts of trypsin to be immobilized, markedly improving the enzymolysis efficiency, compared with traditional modified capillaries. The digestion performance of the trypsin capillary microreactor was further evaluated by digesting cytochrome C, and a peptide numbers of 8, and a sequence coverage of 59% were obtained. This renewable and efficient immobilized trypsin capillary microreactor combines advantages of both DDI technology and PAMAM, and is potentially adaptable to high-throughput enzyme assays in biochemical and clinical research. Copyright © 2018. Published by Elsevier B.V.

Effects of an orally active vasopressin V1 receptor antagonist.

PubMed

Burrell, L M; Phillips, P A; Stephenson, J; Risvanis, J; Hutchins, A M; Johnston, C I

1993-05-01

1. This paper reports on the in vitro and in vivo characteristics of a non-peptide vasopressin V1 receptor antagonist 1-(1-[4-(3-acetylaminopropoxy)benzoyl]-4-piperidyl)-3,4-dihydro-2( 1H)- quinolinone (OPC-21268). 2. OPC-21268 caused a concentration-dependent displacement of the selective V1 receptor antagonist radioligand, [125I]-[d(CH2)5, sarcosine7]AVP from vasopressin V1 receptors in rat liver and kidney membranes, inhibitory concentration of 50% (IC50) 4 x 10(-8), 0.3 mol/L liver and 1.5 x 10(-8), 0.2 mol/L kidney. OPC-21268 had little effect on the selective V2 antagonist radioligand [3H]desGly-NH2(9)-d(CH2)5[D-Ileu2, Ileu4]AVP binding to V2 receptors in renal membranes (IC50 > 10(-4) mol/L). 3. After oral administration to rats, OPC-21268 was an effective V1 antagonist to both liver and kidney V1 receptors, in a dose-dependent manner. 4. These studies confirm that OPC-21268 is a potent non-peptide, orally effective V1 vasopressin receptor antagonist.

[Application of microwave technology in extraction process of Guizhi Fuling capsule].

PubMed

Wang, Zheng-kuan; Zhou, Mao; Liu, Yuan; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei

2015-06-01

In this paper, optimization of the conditions of microwave technique in extraction process of Guizhi Fuling capsule in the condition of a pilot scale was carried out. First of all, through the single factor experiment investigation of various factors, the overall impact tendency and range of each factor were determined. Secondly, L9 (3(4)) orthogonal test optimization was used, and the contents of gallic acid in liquid, paeoniflorin, benzoic acid, cinnamic acid, benzoyl paeoniflorin, amygdalin of the liquid medicine were detected. The extraction rate and comprehensive evaluation were calculated with the extraction effect, as the judgment basis. Theoptimum extraction process of Guizhi Fuling capsule by microwave technology was as follows: the ratio of liquid to solid was 6: 1 added to drinking water, the microwave power was 6 kW, extraction time was 20 min for 3 times. The process of the three batch of amplification through verification, the results are stable, and compared with conventional water extraction has the advantages of energy saving, time saving, high efficiency advantages. The above results show the optimum extracting technology of high efficiency, stable and feasible.

Stereoselective synthesis of novel thioglycosyl heterocycles

NASA Astrophysics Data System (ADS)

El Ashry, El Sayed H.; Awad, Laila F.; Al Moaty, Mohamed N. Abd; Ghabbour, Hazem A.; Barakat, Assem

2018-01-01

In this work, the synthesis of novel 1,2,4-triazole thioglycoside heterocycles 4, 5, and 8 were achieved by the reaction of 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose (2) and galactopyranose (3) with 4-((4-arylidene)amino)-5-methyl-1,2,4-triazole-3-thiol derivatives 1 and 6 in the presence of boron trifluoride etherate (BF3·Et2O) as a promoter under nitrogen in CH2Cl2. Exclusive β-stereoselectivity of the formed glycosidic bond was confirmed by X-ray analysis of 4 as well as its spectral data. Different stereoselectivities were observed when the acceptor 9, having an ortho phenolic OH group, was coupled with the donors 2 or 3, under the same reaction conditions. Similarly, treatment of a mixture of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (16) and the thiol acceptors 1 and 15 afforded the β-thioribofuranosides 17 and 18, respectively. The β-stereoselectivity of the reaction was confirmed by 1H, 13C, 1Hsbnd 1H 2D, and 1Hsbnd 13C 2D NMR spectral analysis.

Reactions of Trimethylsilyl Fluorosulfonyldifluoroacetate with Purine and Pyrimidine Nucleosides

PubMed Central

Rapp, Magdalena; Cai, Xiaohong; Xu, Wei; Dolbier, William R.; Wnuk, Stanislaw F.

2008-01-01

Difluorocarbene, generated from trimethylsilyl fluorosulfonyldifluoroacetate (TFDA), reacts with the uridine and adenosine substrates preferentially at the enolizable amide moiety of the uracil ring and the 6-amino group of the purine ring. 2',3'-Di-O-acetyl-3'-deoxy-3'-methyleneuridine reacts with TFDA to produce 4-O-difluoromethyl product derived from an insertion of difluorocarbene into the 4-hydroxyl group of the enolizable uracil ring. Reaction of the difluorocarbene with the adenosine substrates having the unprotected 6-amino group in the purine ring produced the 6-N-difluoromethyl derivative, while reaction with 6-N-benzoyl protected adenosine analogues gave the difluoromethyl ether product derived from the insertion of difluorocarbene into the enol form of the 6-benzamido group. Treatment of the 6-N-phthaloyl protected adenosine analogues with TFDA resulted in the unexpected one-pot conversion of the imidazole ring of the purine into the corresponding N-difluoromethylthiourea derivatives. Treatment of the suitably protected pyrimidine and purine nucleosides bearing an exomethylene group at carbons 2', 3' or 4' of the sugar rings with TFDA afforded the corresponding spirodifluorocyclopropyl analogues but in low yields. PMID:20160856

Tandem mass spectrometry of nitric oxide and hydrogen sulfide releasing aspirins: a hint into activity behavior.

PubMed

Crestoni, Maria Elisa; Chiavarino, Barbara; Guglielmo, Stefano; Lilla, Valentina; Fornarini, Simonetta

2013-01-01

Aspirin (acetylsalicylic acid, ASA) is the most popular non-steroidal anti-inflammatory drug. However, due to its action on cyclooxygenase and its acid nature, aspirin is associated with adverse gastrointestinal effects. In an effort to minimize these side effects, NO-donor and H2S-donor ASA co-drugs have been designed and tested. Their mass spectrometric behavior is now analyzed and reported. Positive ions were obtained by electrospray ionization involving protonation or alkali metal attachment. Their dissociation processes have been studied by collision induced dissociation in a triple quadrupole instrument. High mass accuracy measurements have been recorded on a Fourier transform ion cyclotron resonance mass spectrometer. The protonated molecules dissociate by an exclusive or largely prevailing path leading to acetyloxy-substituted benzoyl cation, namely an ASA unit. The process is reminiscent of the enzymatic hydrolysis, releasing intact ASA to a large extent. Only at higher collision energy does the formal ketene loss disrupt the ASA moiety. The gas phase chemistry of protonated ASA-releasing drugs develops along elementary dissociation steps analogous to the reactive processes in complex biological environments. This notion may provide a tool for preliminary testing of new compounds.

Sorption and selective chromatographic properties of isomer-selective composite sorbent based on a eutectic mixture of nematic liquid crystals and perbenzoylated β-cyclodextrin

NASA Astrophysics Data System (ADS)

Onuchak, L. A.; Kapralova, T. S.; Kuraeva, Yu. G.; Belousova, Z. P.; Stepanova, R. F.

2015-12-01

Mesomorphic, sorption, and selective properties of a three-component sorbent based on a mixture of nematic ( N) liquid crystals of 4-methoxy-4'-ethoxyazoxybenzene (MEAB) and 4,4'-diethoxyazoxybenzene (azoxyphenetol, AOP) of an eutectic composition and heptakis-(2,3,6-tri- O-benzoyl)-β-cyclodextrin (Bz-β-CD) are studied. For 30 organic compounds of different classes with linear and cyclic molecular structures, including optical isomers of limonene, pinene, camphene, and butanediol-2,3, thermodynamic functions are determined for their gas-phase sorption using a three-component MEAB-AOP-Bz-β- CD sorbent (62: 28: 10 wt %). It is found that the investigated sorbent possesses high structural selectivity (αp/m = 1.128-1.059, 100-130°C, N) and moderate enantioselectivity (1.07-1.02) within a broad temperature range (95-170°C) including both mesomorphic and isotropic phases of the sorbent. It is shown that the enantioselectivity of the sorbent is apparent under conditions of both increasing retention when a chiral Bz-β-CD additive is introduced into the MEAB-AOP system (limonenes, pinenes, camphenes) and decreasing retention (butanediols-2,3).

The separation of 99Tc from low and medium-level radioactive wastes and its determination by inductively coupled plasma mass spectrometry.

PubMed

Hepiegne, P; Dall'ava, D; Clement, R; Degros, J P

1995-06-01

A chemical separation method has been developed for the determination of (99)Tc in various types of radioactive wastes. Such a method includes (i) fusion with NaOH, (ii) extraction in a column containing methyltrioctylammonium chloride, (iii) extraction by solvent with N-benzoyl-N-phenylhydroxylamine and, (iv) measurement by inductively-coupled plasma mass spectrometry (ICP-MS). From the performance standpoint, the recovery of (99)Tc, using (99m)Tc as a yield tracer, is higher than 70%. This analytical method, as developed, ensures effective decontamination with respect to the radionuclides, insofar the decontamination factors are greater than 10(+5), whenever the residual activity may be measured. Taking into account a 3sigma counting error, the detection limit obtained with the ICP-MS technique is 1.9 mBq/ml; the method enabling hence to detect activities as low as 0.3 Bq/g, with analysed samples of 0.2 g and a radiochemical yield of 70%. Studies have been dedicated to the (99)Tc measurement, using the electrothermal vaporization ICP-MS technique, which lowers the detection limit by a factor 10, with the standard solution (0.3 pg/ml), compared with the previous ICP-MS technique.

Chemically induced graft copolymerization of 2-hydroxyethyl methacrylate onto polyurethane surface for improving blood compatibility

NASA Astrophysics Data System (ADS)

He, Chunli; Wang, Miao; Cai, Xianmei; Huang, Xiaobo; Li, Li; Zhu, Haomiao; Shen, Jian; Yuan, Jiang

2011-11-01

To improve hydrophilicity and blood compatibility properties of polyurethane (PU) film, we chemically induced graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto the surface of polyurethane film using benzoyl peroxide as an initiator. The effects of grafting temperature, grafting time, monomer and initiator concentrations on the grafting yields were studied. The maximum grafting yield value was obtained 0.0275 g/cm2 for HEMA. Characterization of the films was carried out by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements. ATR-FTIR data showed that HEMA was successfully grafted onto the PU films surface. Water contact angle measurement demonstrated the grafted films possessed a relatively hydrophilic surface. The blood compatibility of the grafted films was preliminarily evaluated by a platelet-rich plasma adhesion test and hemolysis test. The results of platelet adhesion experiment showed that polyurethane grafted polymerization with monomer of 2-hydroxyethyl methacrylate had good blood compatibility featured by the low platelet adhesion. Hemolysis rate of the PU-g-PHEMA films was dramatically decreased than the ungrafted PU films. This kind of new biomaterials grafted with HEMA monomers might have a potential usage for biomedical applications.

Determination of residual monomers resulting from the chemical polymerization process of dental materials

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

Boboia, S.; Moldovan, M.; Ardelean, I.

The residual monomer present in post-polymerized dental materials encourages premature degradation of the reconstructed tooth. That is why the residual monomer should be quantified in a simple, fast, accurate and reproducible manner. In our work we propose such an approach for accurate determination of the residual monomer in dental materials which is based on low-field nuclear magnetic resonance (NMR) relaxometry. The results of the NMR approach are compared with those of the high performance liquid chromatography (HPLC) technique. The samples under study contain the main monomers (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane and triethylene glycol dimethacrylate) constituting the liquid phase of most dental materials andmore » an initiator. Two samples were analyzed with different ratios of chemical initiation systems: N,N-dimethyl-p-toluide: benzoyl peroxide (1:2 and 0.7:1.2). The results obtained by both techniques highlight that by reducing the initiator the polymerization process slows down and the amount of residual monomer reduces. This prevents the premature degradation of the dental fillings and consequently the reduction of the biomaterial resistance.« less

Pyridones as NNRTIs against HIV-1 mutants: 3D-QSAR and protein informatics

NASA Astrophysics Data System (ADS)

Debnath, Utsab; Verma, Saroj; Jain, Surabhi; Katti, Setu B.; Prabhakar, Yenamandra S.

2013-07-01

CoMFA and CoMSIA based 3D-QSAR of HIV-1 RT wild and mutant (K103, Y181C, and Y188L) inhibitory activities of 4-benzyl/benzoyl pyridin-2-ones followed by protein informatics of corresponding non-nucleoside inhibitors' binding pockets from pdbs 2BAN, 3MED, 1JKH, and 2YNF were analysed to discover consensus features of the compounds for broad-spectrum activity. The CoMFA/CoMSIA models indicated that compounds with groups which lend steric-cum-electropositive fields in the vicinity of C5, hydrophobic field in the vicinity of C3 of pyridone region and steric field in aryl region produce broad-spectrum anti-HIV-1 RT activity. Also, a linker rendering electronegative field between pyridone and aryl moieties is common requirement for the activities. The protein informatics showed considerable alteration in residues 181 and 188 characteristics on mutation. Also, mutants' isoelectric points shifted in acidic direction. The study offered fresh avenues for broad-spectrum anti-HIV-1 agents through designing new molecules seeded with groups satisfying common molecular fields and concerns of mutating residues.

Synthesis and application of a nanoporous ion-imprinted polymer for the separation and preconcentration of trace amounts of vanadium from food samples before determination by electrothermal atomic absorption spectrometry.

PubMed

Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Dehghanpoor Frashah, Shahab

2016-04-01

A vanadium ion-imprinted polymer was synthesized in the presence of V(V) and N-benzoyl-N-phenyl hydroxyl amine using 4-vinyl pyridine as the monomer, ethylene glycol dimethacrylate as the cross linker and 2,2'-azobis(isobutyronitrile) as the initiator. The imprinted V(V) ions were completely removed by leaching the polymer with 5 mol/L nitric acid, and the polymer structure was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The ion-imprinted polymer was used as the sorbent in the development of the solid-phase extraction method for V(V) prior to its determination by electrothermal atomic absorption spectrometry. The maximum sorption capacity for V(V) ions was 26.7 mg/g at pH 4.0. Under the optimum conditions, for a sample volume of 150.0 mL, an enrichment factor of 289.0 and a detection limit of 6.4 ng/L were obtained. The developed method was successfully applied to the determination of vanadium in parsley, zucchini, black tea, rice, and water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanistic studies on the phosphoramidite coupling reaction in oligonucleotide synthesis. I. Evidence for nucleophilic catalysis by tetrazole and rate variations with the phosphorus substituents.

PubMed Central

Dahl, B H; Nielsen, J; Dahl, O

1987-01-01

Tetrazole catalyzed reactions of a series of phosphoramidites, 5'-O-DMTdT-3'-O-P(OR1)NR2(2) (1a-h), with 3'-O-SiButPh2-6-N-benzoyl-dA (2a) in acetonitrile solution have been studied. It is found that the coupling rate depends very much on whether tetrazole is added before or after 2a, and that dialkylammonium tetrazolide salts are inhibitors. These and other facts are evidence that the reactions are subjected to nucleophilic catalysis by tetrazole, in addition to acid catalysis. The rate variations with phosphorus substituents of 1a-h are NEt2 greater than NPri2 greater than N(CH2CH2)O greater than NMePh, and OMe greater than OCH2CH2CN greater than OCHMeCH2CN greater than OCMe2CH2CN much greater than OC6H4Cl. The inhibitor properties of dialkylammonium tetrazolides have practical consequences for the efficiency of DNA syntheses, when in situ prepared phosphoramidites are used; the same would apply for segmented, simultaneous syntheses or syntheses where recycling is performed. PMID:3822837

Active Site Mapping of Xylan-Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly.

PubMed

Senf, Deborah; Ruprecht, Colin; de Kruijff, Goswinus H M; Simonetti, Sebastian O; Schuhmacher, Frank; Seeberger, Peter H; Pfrengle, Fabian

2017-03-02

Xylan-degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2-substituted, 3-substituted, and 2-/3-substituted arabino- and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4-fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker-functionalized resin. Arabinofuranose and glucuronic acid residues have been selectively attached to the backbone using fully orthogonal 2-(methyl)naphthyl (Nap) and 2-(azidomethyl)benzoyl (Azmb) protecting groups at the C2 and C3 hydroxyls of the xylose building blocks. The arabinoxylan oligosaccharides are excellent tools to map the active site of glycosyl hydrolases involved in xylan deconstruction. The substrate specificities of several xylanases and arabinofuranosidases were determined by analyzing the digestion products after incubation of the oligosaccharides with glycosyl hydrolases. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phase behavior and transitions of self-assembling nano-structured materials

NASA Astrophysics Data System (ADS)

Duan, Hu

Homologous series of supramolecular nanostructures have been investigated by a combination of transmission electron microscopy (TEM), electron diffraction (ED), thermal polarized optical microscopy and X-ray diffraction (XRD). Materials include amphiphilic oligomers and polymer such as charged complexes, dipeptide dendrons semi-fluorinated dendron and polyethyleneimines. Upon microphase separation, they self-assemble into either cylindrical or spherical shapes, which co-organize into a 2D P6mm hexagonal columnar phase or 3D Pm 3¯ n and Im 3¯ m cubic phases. Correlation between the phase selection and molecular architecture is established accordingly. The order-disorder transition (ODT) is explored by rheometry and rheo-optical microscopy in a model polymeric compound poly(N-[3,4-bis(n-dodecan-1-yloxy)benzoyl]ethyleneimine). Shear alignment of the hexagonal columnar liquid crystalline phase along the velocity direction at low temperature and shear disordering in the vicinity of the ODT were observed. After cessation of shear, transformation back to the stable columnar phase follows a row-nucleation mechanism. The order-order transition process is explored in a monodendron that exhibits a hexagonal columnar and a weakly birefringent mesophase. Polarized DIC microscopy strongly supports an epitaxial relationship between them.

New Boron Analogues of Pyrophosphates and Deoxynucleoside Boranophosphates

PubMed Central

Vyakaranam, Kamesh; Rana, Geeta; Spielvogel, Bernard F.

2001-01-01

Tetraethyldicyanoborane pyrophosphate (2) and 3'-(diethylphosphite-cyanoborano)-5'-dimethoxytrityl.N4-benzoyl-deoxycytidine (3) have been synthesized in 70% and 76% yields, respectively. The compatibility of the substituted boranophosphates with common protecting groups is hereby demonstrated. Boron containing biologically active compounds, such as nucleosides and nucleotides 1-6 and amino acids 7-9 are important due to their potential therapeutic activity, research and diagnostic applications. Many boron containing compounds have shown promising activity as anticancer, 10. 11. 12 antiinflammatory,13 and antiosteoporotic 13agents. Oligonucleotdes in which a non-bridging oxygen atom is replaced by a borane(BH3) group are a very important class of modified nucleic acids. 1. 3. 14-16 The BH3 group is isoelectronic with oxygen in natural oligonucleotides and isoelectronic and isostructural with the oligonucleotide methyl phosphonates, which are nuclease resistant. On the other hand, the α-borano triphosphates are good substrates for DNA polymerases and incorporation of boranophosphates into DNA causes an increase in the resistance to exo- and endonucleases 2. 17a as compared to non-modified DNA. There are also notable applications of the α-borano triphosphates in PCR sequencing 17a and nucleic acid detection 17b. PMID:18475988

Redox Polypharmacology as an Emerging Strategy to Combat Malarial Parasites.

PubMed

Sidorov, Pavel; Desta, Israel; Chessé, Matthieu; Horvath, Dragos; Marcou, Gilles; Varnek, Alexandre; Davioud-Charvet, Elisabeth; Elhabiri, Mourad

2016-06-20

3-Benzylmenadiones are potent antimalarial agents that are thought to act through their 3-benzoylmenadione metabolites as redox cyclers of two essential targets: the NADPH-dependent glutathione reductases (GRs) of Plasmodium-parasitized erythrocytes and methemoglobin. Their physicochemical properties were characterized in a coupled assay using both targets and modeled with QSPR predictive tools built in house. The substitution pattern of the west/east aromatic parts that controls the oxidant character of the electrophore was highlighted and accurately predicted by QSPR models. The effects centered on the benz(o)yl chain, induced by drug bioactivation, markedly influenced the oxidant character of the reduced species through a large anodic shift of the redox potentials that correlated with the redox cycling of both targets in the coupled assay. Our approach demonstrates that the antimalarial activity of 3-benz(o)ylmenadiones results from a subtle interplay between bioactivation, fine-tuned redox properties, and interactions with crucial targets of P. falciparum. Plasmodione and its analogues give emphasis to redox polypharmacology, which constitutes an innovative approach to antimalarial therapy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Physicochemical, Stress Degradation Evaluation and Pharmacokinetic Study of AZGH102, a New Synthesized COX2 Inhibitors after I.V. and Oral Administration in Male and Female Rats.

PubMed

Bahmanof, Hoda; Dadashzadeh, Simin; Zarghi, Afshin; Shafaati, Alireza; Foroutan, Seyed Mohsen

2017-01-01

Coxibs such as celecoxib, rofecoxib, and valdecoxib are introduced as selective COX-2 inhibitors to the market. It has been reported that inhibition of COX-2 beside traditional effects of NSAIDs, reduces the risk of colorectal, breast and lung cancers and also slow the progress of Alzheimer's disease. Zarghi et al. reported 8-benzoyl-2-(4-(methylsulfonyl)phenyl)quinoline-4-carboxylic acid (AZGH 102) as a novel compound with similar IC50 to celecoxib besides improved selectivity index (COX-1/COX-2 inhibitory potency) in comparison with celecoxib. In this study, the physicochemical properties of AZGH 102 such as solubility, log P, and stability were evaluated and the pharmacokinetic characteristics of this compound following intravenous (10 mg/Kg), and oral administration (20 mg/Kg), to male and female Wistar rats were investigated. As the data demonstrated, the AZGH 102 classified as lipophil compound and had suitable stability. This derivative absorbs and distributes faster in female than in male. The AUC 0-∞, absolute bioavailability, Cl and Vd were different in both sexes. According to the obtained data, the AZGH 102 has a sex dependent pharmacokinetic in Wistar rats.

Synthetic mucin fragments: synthesis of O-sulfo and O-methyl derivatives of allyl O-(beta-D-galactopyranosyl)-(1-->3)-2-acetamido-2-deoxy-alpha-D- galactopyranoside as potential compounds for sulfotransferases.

PubMed

Jain, R K; Piskorz, C F; Matta, K L

1995-10-02

Allyl 2-acetamido-4,6-O-(4-methoxybenzylidene)-2-deoxy-alpha-D-galact opy ranoside (1) was condensed with either 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide (2) or 2,3,4-tri-O-benzoyl-6-O-bromoacetyl-alpha-D-galactopyranosyl bromide (14) in the presence of mercuric cyanide. Selective substitution with methyl, sulfo or both at desired positions, followed by the removal of protecting groups, afforded allyl O-(beta-D-galactopyranosyl)-(1-->3)-2-acetamido-2-deoxy-6-O-methyl-alpha -D- galactopyranoside (5), allyl O-(6-O-sulfo-beta-D-galactopyranosyl sodium salt)-(1-->3)-2-acetamido-2-deoxy-6- O-methyl-alpha-D-galactopyranoside (10), allyl O-(beta-D-galactopyranosyl)-(1-->3)-2-acetamido-2-deoxy-6-O-sulfo-alpha- D- galactopyranoside sodium salt (13), allyl O-(6-O-sulfo-beta-D-galactopyranosyl sodium salt)-(1-->3)-2-acetamido-2-deoxy- alpha-D-galactopyranoside (17) and allyl O-(3-O-sulfo-beta-D-galactopyranosyl sodium salt)-(1-->3)-2-acetamido-2-deoxy- alpha-D-galactopyranoside (22). The structures of compounds 5, 10, 13, 17 and 22 were established by 13C NMR and FAB mass spectroscopy.

Adjuvant alternative treatment with chemical peeling and subsequent iontophoresis for postinflammatory hyperpigmentation, erosion with inflamed red papules and non-inflamed atrophic scars in acne vulgaris.

PubMed

Kurokawa, Ichiro; Oiso, Naoki; Kawada, Akira

2017-04-01

The standard management of acne vulgaris in Japan includes a combination of topical treatment with benzoyl peroxide (BPO) and BPO/clindamycin (CLDM), topical adapalene and systemic antimicrobials. However, the treatment of therapy-resistant complications such as postinflammatory hyperpigmentation (PIH), erosions with inflamed red papules and atrophic scars has not been established. We performed chemical peeling with glycolic acid and iontophoresis with ascorbyl 2-phosphate 6-palmitate and DL-α-tocopherol phosphate for the treatment of PIH, erosions with inflamed red papules and non-inflamed atrophic scars in 31 patients with acne vulgaris (mild to severe severity), and evaluated the efficacy and safety of these interventions. In most of cases, there was remarkable improvement in PIH and erosions with inflamed red papules after treatment. There was also some improvement in non-inflamed atrophic scars without erythema. Mild redness and irritation was observed in four cases as adverse reactions. Early initial treatment of PIH and erosions with red papules by chemical peeling and iontophoresis is an effective and safe method to prevent the formation of atrophic scars in patients with acne vulgaris. © 2016 Japanese Dermatological Association.

Calculated third order rate constants for interpreting the mechanisms of hydrolyses of chloroformates, carboxylic Acid halides, sulfonyl chlorides and phosphorochloridates.

PubMed

Bentley, T William

2015-05-08

Hydrolyses of acid derivatives (e.g., carboxylic acid chlorides and fluorides, fluoro- and chloroformates, sulfonyl chlorides, phosphorochloridates, anhydrides) exhibit pseudo-first order kinetics. Reaction mechanisms vary from those involving a cationic intermediate (SN1) to concerted SN2 processes, and further to third order reactions, in which one solvent molecule acts as the attacking nucleophile and a second molecule acts as a general base catalyst. A unified framework is discussed, in which there are two reaction channels-an SN1-SN2 spectrum and an SN2-SN3 spectrum. Third order rate constants (k3) are calculated for solvolytic reactions in a wide range of compositions of acetone-water mixtures, and are shown to be either approximately constant or correlated with the Grunwald-Winstein Y parameter. These data and kinetic solvent isotope effects, provide the experimental evidence for the SN2-SN3 spectrum (e.g., for chloro- and fluoroformates, chloroacetyl chloride, p-nitrobenzoyl p-toluenesulfonate, sulfonyl chlorides). Deviations from linearity lead to U- or V-shaped plots, which assist in the identification of the point at which the reaction channel changes from SN2-SN3 to SN1-SN2 (e.g., for benzoyl chloride).

Brilliant blue FCF as an alternative dye for saphenous vein graft marking: effect on conduit function.

PubMed

Voskresensky, Igor V; Wise, Eric S; Hocking, Kyle M; Li, Fan Dong; Osgood, Michael J; Komalavilas, Padmini; Brophy, Colleen; Cheung-Flynn, Joyce

2014-11-01

inferior venae cavae, FCF inhibited the contraction induced by the P2X7 receptor agonist 2'(3')-O-(4-benzoyl)benzoyl-adenosine-5'-triphosphate (mean [SEM], 14.8% [2.2%] vs 6.5% [1.8%]; P = .02) to an extent similar to the P2X7 receptor antagonist oxidized adenosine triphosphate (mean [SEM], 5.0% [0.9%]; P < .02 vs control) or the pannexin hemichannel inhibitor probenecid (mean [SEM], 7.3% [1.6%] and 4.7% [0.9%] for 0.5mM and 2mM, respectively; P < .05). Treatment with FCF did not impair endothelial or smooth muscle function in HSVs. Brilliant blue FCF enhanced endothelial-dependent relaxation, restored smooth muscle function, and prevented intimal hyperplasia in HSVs in organ culture. These pharmacological properties of FCF may be due to P2X7 receptor or pannexin channel inhibition. Brilliant blue FCF is an alternative, nontoxic marking dye that may improve HSV conduit function and decrease intimal hyperplasia.

Direct functionalization processes: a journey from palladium to copper to iron to nickel to metal-free coupling reactions.

PubMed

Mousseau, James J; Charette, André B

2013-02-19

The possibility of finding novel disconnections for the efficient synthesis of organic molecules has driven the interest in developing technologies to directly functionalize C-H bonds. The ubiquity of these bonds makes such transformations attractive, while also posing several challenges. The first, and perhaps most important, is the selective functionalization of one C-H bond over another. Another key problem is inducing reactivity at sites that have been historically unreactive and difficult to access without prior inefficient prefunctionalization. Although remarkable advances have been made over the past decade toward solving these and other problems, several difficult tasks remain as researchers attempt to bring C-H functionalization reactions into common use. The functionalization of sp(3) centers continues to be challenging relative to their sp and sp(2) counterparts. Directing groups are often needed to increase the effective concentration of the catalyst at the targeted reaction site, forming thermodynamically stable coordination complexes. As such, the development of removable or convertible directing groups is desirable. Finally, the replacement of expensive rare earth reagents with less expensive and more sustainable catalysts or abandoning the use of catalysts entirely is essential for future practicality. This Account describes our efforts toward solving some of these quandaries. We began our work in this area with the direct arylation of N-iminopyridinium ylides as a universal means to derivatize the germane six-membered heterocycle. We found that the Lewis basic benzoyl group of the pyridinium ylide could direct a palladium catalyst toward insertion at the 2-position of the pyridinium ring, forming a thermodynamically stable six-membered metallocycle. Subsequently we discovered the arylation of the benzylic site of 2-picolonium ylides. The same N-benzoyl group could direct a number of inexpensive copper salts to the 2-position of the pyridinium ylide

13C and 15N Solid State MMR Characterization of Aramid-Containing Nylon-6 by In Situ Polymerization with Benzoyl Caprolactam Derivatives.

DTIC Science & Technology

1987-12-01

areas consistant with the alternating copolymer structure. Comparison with the model acetanilide (-241.9) indicates the downfield resonance is due to the...Deguchi, l.; Ando, 1. Macromclecule’-, 1987, 20, 2441. 4 S..:! TABLE I CP-NIAS u N-methyl benzainide -23. 3 2 Acetanilide -241.9 ’iC poly(p-benzamide

Characterization of bimetallic Fe/Pd nanoparticles by grape leaf aqueous extract and identification of active biomolecules involved in the synthesis.

PubMed

Luo, Fang; Yang, Die; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravi

2016-08-15

This paper reports the detailed composition and morphology of one-step green synthesized bimetallic Fe/Pd nanoparticles (NPs) using grape leaf aqueous extract and identification of active biomolecules involved in the synthesis employing various techniques. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) revealed that Fe/Pd NPs were polydispersed and quasi-spherical with a diameter ranging from 2 to 20nm. X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive X-ray Spectroscopy (EDS) provided evidence for the composition of Fe and Pd and for their species existing on the surface of Fe/Pd NPs. In addition, biomolecules in the grape leaf aqueous extract were identified but their functions are still unclear. Biomolecules in the aqueous extract such as methoxy-phenyl-oxime, N-benzoyl-2-cyano-histamine, 2-ethyl-phenol, 1,2-benzenediol, β-hydroxyquebracamine, hydroquinone, 2-methoxy-4-vinylphenol, 5-methyl-2-furancarboxaldehyde, 4-(3-hydroxybutyl)-3,5,5-trimethyl-2-cyclohexen and some polyphenolic compounds were identified as reducing and capping agents, which were studied by Chromatography-Mass Spectroscopy (GC-MS), XPS and Fourier Transform Infrared Spectroscopy (FTIR). Our finding suggests a new insight into cost-effective, simple, and environmentally benign production of bimetallic Fe/Pd NPs. Copyright © 2016 Elsevier B.V. All rights reserved.

A new series of highly potent growth hormone-releasing peptides derived from ipamorelin.

PubMed

Ankersen, M; Johansen, N L; Madsen, K; Hansen, B S; Raun, K; Nielsen, K K; Thogersen, H; Hansen, T K; Peschke, B; Lau, J; Lundt, B F; Andersen, P H

1998-09-10

A new series of GH secretagogues derived from ipamorelin is described. In an attempt to obtain oral bioavailability, by reducing the size and the number of potential hydrogen-bonding sites of the compounds, a strategy using the peptidomimetic fragment 3-(aminomethyl)benzoic acid and sequential backbone N-methylations was applied. Several compounds from this series release GH with high in vitro potency and efficacy in a rat pituitary cell assay and high in vivo potency and efficacy in anesthetized rats. The tetrapeptide NNC 26-0235 (3-(aminomethyl)benzoyl-D-2Nal-N-Me-D-Phe-Lys-NH2) shows, following iv administration, comparable in vivo potency to ipamorelin, GHRP-2, and GHRP-6 with an ED50 in swine at 2 nmol/kg. NNC 26-0235 demonstrated a 10% oral bioavailability in dogs, and NNC 26-0235 and ipamorelin were able to increase basal GH level by more than 10-fold after oral administration of a dose of 1.8 and 2.7 mg/kg, respectively. The tripeptide NNC 26-0323 (3-(aminomethyl)benzoic acid-N-Me-D-2Nal-N-Me-D-Phe-ol) which showed moderate in vitro potency but lacked in vivo potency demonstrated a 20% oral bioavailability in rats.

A Specific Hepatic Transfer RNA for Phosphoserine*

PubMed Central

Mäenpää, Pekka H.; Bernfield, Merton R.

1970-01-01

Radioactive O-phosphoryl-L-serine was detected after alkaline deacylation of rat and rooster liver [3H]seryl-tRNA acylated in vitro with homologous synthetases. Ribonuclease treatment of this tRNA yielded a compound with the properties of phosphoseryl-adenosine. Benzoylated DEAE-cellulose chromatography of seryl-tRNA yielded four distinct peaks, only one of which contained phosphoserine. A unique fraction for phosphoserine was also found on chromatography of nonacylated tRNA. In ribosome binding studies, this fraction responded very slightly with poly(U,C), but not with any of the known serine trinucleotide codons. Substantial incorporation of [3H]-serine into protein from this tRNA species was observed in an aminoacyl-tRNA dependent polysomal system derived from chick oviducts. No phosphoserine was found in Escherichia coli or yeast seryl-tRNA acylated with homologous enzymes, nor in E. coli seryl-tRNA acylated with liver synthetase. In the absence of tRNA, free phosphoserine was not formed in reaction mixtures, which suggests that phosphoseryl-tRNA arises by phosphorylation of the unique seryl-tRNA species. These results demonstrate a discrete tRNASer species in rat and rooster liver containing phosphoserine and suggest that this tRNA is involved in ribosomal polypeptide synthesis. PMID:4943179

Safety and efficacy of micronized tretinoin gel (0.05%) in treating adolescent acne.

PubMed

Torok, Helen M; Pillai, Radhakrishan

2011-06-01

Tretinoin is widely used in the treatment of acne. Despite significant advances in formulation development, irritation and dryness can be particularly bothersome, especially during the first 3-4 weeks, impacting adherence. Dose titration and adjunct use of moisturizers have been commonly employed. Co-prescribing with benzoyl peroxide (BPO) or a BPO/antibiotic combination is also common practice. The tretinoin molecule is unstable and can be degraded by BPO, further complicating treatment regimens. Lately, formulation technology has focused on providing more efficient penetration of the tretinoin into the skin layers so that lower concentrations of tretinoin might afford better tolerability, but maintain good efficacy; incorporating moisturizing excipients to minimize irritation; and providing greater stability to the tretinoin molecule. This approach would be particularly relevant in a pediatric acne population where efficacy/tolerability balance is important and treatment regimens must take into account lifestyles, but little data exist on the use of tretinoin in this patient population. A micronized formulation of tretinoin (0.05%) gel has been developed that provides a more efficient delivery of tretinoin, because of its optimal particle size, no degradation by BPO and better cutaneous tolerability than tretinoin microsphere (0.1%) gel without compromising efficacy in a pediatric population.

Acne vulgaris

PubMed Central

2011-01-01

Introduction Acne vulgaris affects over 80% of teenagers, and persists beyond the age of 25 years in 3% of men and 12% of women. Typical lesions of acne include comedones, inflammatory papules, and pustules. Nodules and cysts occur in more severe acne and can cause scarring and psychological distress. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of topical and oral treatments in people with acne vulgaris? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 69 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: topical treatments (adapalene, azelaic acid, benzoyl peroxide, clindamycin, erythromycin [alone or plus zinc]; isotretinoin, tetracycline, tretinoin); and oral treatments (doxycycline, isotretinoin, lymecycline, minocycline, oxytetracycline, tetracycline). PMID:21477388

Biochemical Characterization of An Arginine-Specific Alkaline Trypsin from Bacillus licheniformis.

PubMed

Gong, Jin-Song; Li, Wei; Zhang, Dan-Dan; Xie, Min-Feng; Yang, Biao; Zhang, Rong-Xian; Li, Heng; Lu, Zhen-Ming; Xu, Zheng-Hong; Shi, Jin-Song

2015-12-17

In the present study, we isolated a trypsin-producing strain DMN6 from the leather waste and identified it as Bacillus licheniformis through a two-step screening strategy. The trypsin activity was increased up to 140 from 20 U/mL through culture optimization. The enzyme was purified to electrophoretic homogeneity with a molecular mass of 44 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the specific activity of purified enzyme is 350 U/mg with Nα-Benzoyl-L-arginine ethylester as the substrate. The optimum temperature and pH for the trypsin are 65 °C and pH 9.0, respectively. Also, the enzyme can be significantly activated by Ba(2+). This enzyme is relatively stable in alkaline environment and displays excellent activity at low temperatures. It could retain over 95% of enzyme activity after 180 min of incubation at 45 °C. The distinguished activity under low temperature and prominent stability enhance its catalytic potential. In the current work, the open reading frame was obtained with a length of 1371 nucleotides that encoded a protein of 456 amino acids. These data would warrant the B. licheniformis trypsin as a promising candidate for catalytic application in collagen preparation and leather bating through further protein engineering.

Chemical modification of magnetite nanoparticles and preparation of acrylic-base magnetic nanocomposite particles via miniemulsion polymerization

NASA Astrophysics Data System (ADS)

Mahdieh, Athar; Mahdavian, Ali Reza; Salehi-Mobarakeh, Hamid

2017-03-01

Nowadays, magnetic nanocomposite particles have attracted many interests because of their versatile applications. A new method for chemical modification of Fe3O4 nanoparticles with polymerizable groups is presented here. After synthesis of Fe3O4 nanoparticles by co-precipitation method, they were modified sequentially with 3-aminopropyl triethoxysilane (APTES), acryloyl chloride (AC) and benzoyl chloride (BC) and all were characterized by FTIR, XRD, SEM and TGA analyses. Then the modified magnetite nanoparticles with unsaturated acrylic groups were copolymerized with methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA) through miniemulsion polymerization. Although several reports exist on preparation of magnetite-base polymer particles, but the efficiency of magnetite encapsulationwith reasonable content and obtaining final stable latexes with limited aggregation ofFe3O4 are still important issues. These were considered here by controlling reaction parameters. Hence, a seriesofmagneticnanocomposites latex particlescontaining different amounts of Fe3O4 nanoparticles (0-10 wt%) were prepared with core-shell morphology and diameter below 200 nm and were characterized by FT-IR, DSC and TGA analyses. Their morphology and size distribution were studied by SEM, TEM and DLS analyses too. Magnetic properties of all products were also measuredby VSM analysis and the results revealed almost superparamagnetic properties for the obtained nanocomposite particles.

Structure-activity relationship study and optimisation of 2-aminopyrrole-1-benzyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile as a broad spectrum metallo-β-lactamase inhibitor.

PubMed

McGeary, Ross P; Tan, Daniel T C; Selleck, Christopher; Monteiro Pedroso, Marcelo; Sidjabat, Hanna E; Schenk, Gerhard

2017-09-08

A SAR study on derivatives of 2-amino-1-benzyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile 5a revealed that the 3-carbonitrile group, vicinal 4,5-diphenyl and N-benzyl side chains of the pyrrole are important for the inhibitory potencies of these compounds against members representing the three main subclasses of metallo-β-lactamases (MBLs), i.e. IMP-1 (representing the B1 subgroup), CphA (B2) and AIM-1 (B3). Coupling of 5a with a series of acyl chlorides and anhydrides led to the discovery of two N-acylamide derivatives, 10 and 11, as the two most potent IMP-1 inhibitors in this series. However, these compounds are less effective towards CphA and AIM-1. The N-benzoyl derivative of 5a retained potent in vitro activity against each of MBLs tested (with inhibition constants in the low μM range). Importantly, this compound also significantly enhanced the sensitivity of IMP-1, CphA- or AIM-1-producing cell cultures towards meropenem. This compound presents a promising starting point for the development of a universal MBL inhibitor, targeting members of each of the major subgroups of this family of enzymes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The structure of 3'-O-anthraniloyladenosine, an analogue of the 3'-end of aminoacyl-tRNA.

PubMed Central

Nawrot, B; Milius, W; Ejchart, A; Limmer, S; Sprinzl, M

1997-01-01

3'-O-Anthraniloyladenosine, an analogue of the 3'- terminal aminoacyladenosine residue in aminoacyl-tRNAs, was prepared by chemical synthesis, and its crystal structure was determined. The sugar pucker of 3'-O-anthraniloyladenosine is 2'-endo resulting in a 3'-axial position of the anthraniloyl residue. The nucleoside is insynconformation, which is stabilized by alternating stacking of adenine and benzoyl residues of the neighboring molecules in the crystal lattice. The conformation of the 5'-hydroxymethylene in 3'-O- anthraniloyladenosine is gauche-gauche. There are two intramolecular and two intermolecular hydrogen bonds and several H-bridges with surrounding water molecules. The predominant structure of 3'-O-anthraniloyladenosine in solution, as determined by NMR spectroscopy, is 2'-endo,gauche-gauche and anti for the sugar ring pucker, the torsion angle around the C4'-C5'bond and the torsion angle around the C1'-N9 bond, respectively. The 2'-endo conformation of the ribose in 2'(3')-O-aminoacyladenosine, which places the adenine and aminoacyl residues in equatorial and axial positions, respectively, could serve as a structural element that is recognized by enzymes that interact with aminoacyl-tRNA or by ribosomes to differentiate between aminoacylated and non-aminoacylated tRNA. PMID:9023103

Molecular architectures of benzoic acid-specific type III polyketide synthases

PubMed Central

Stewart, Charles; Woods, Kate; Macias, Greg; Allan, Andrew C.; Noel, Joseph P.

2017-01-01

Biphenyl synthase and benzophenone synthase constitute an evolutionarily distinct clade of type III polyketide synthases (PKSs) that use benzoic acid-derived substrates to produce defense metabolites in plants. The use of benzoyl-CoA as an endogenous substrate is unusual for type III PKSs. Moreover, sequence analyses indicate that the residues responsible for the functional diversification of type III PKSs are mutated in benzoic acid-specific type III PKSs. In order to gain a better understanding of structure–function relationships within the type III PKS family, the crystal structures of biphenyl synthase from Malus × domestica and benzophenone synthase from Hypericum androsaemum were compared with the structure of an archetypal type III PKS: chalcone synthase from Malus × domestica. Both biphenyl synthase and benzophenone synthase contain mutations that reshape their active-site cavities to prevent the binding of 4-coumaroyl-CoA and to favor the binding of small hydrophobic substrates. The active-site cavities of biphenyl synthase and benzophenone synthase also contain a novel pocket associated with their chain-elongation and cyclization reactions. Collectively, these results illuminate structural determinants of benzoic acid-specific type III PKSs and expand the understanding of the evolution of specialized metabolic pathways in plants. PMID:29199980

Relationship between the formation of volatile sulfur compounds (VSC) and the severity of the periodontal disease: a pilot study.

PubMed

Nogueira-Filho, G R; Peruzzo, D; Sallum, A W

2008-03-01

This aim of this study was to evaluate the relationship between the formation of volatile sulfur compounds (VSC) and the severity of different kinds of periodontal disease. Twenty patients suffering from biofilm-related periodontal diseases and a control group of ten healthy individuals were selected. The patients were divided according to their periodontal diagnoses: marginal gingivitis (MG/n = 10) and chronic periodontitis (CP/n = 10). The patients received non-surgical therapy that consisted of motivation, scaling and root planing. Two experimental periods were used: T1 = baseline and T2 = final evaluation after three months. The data analysis showed that CP group had a significant reduction (p < 0.05) in probing depth (PD) and clinical attachment level (CAL), and group MG presented a reduction in GI (p < 0.05). There was a significant reduction (p < 0.05) in the aspartate aminotransferase (AST), N-a-benzoyl-DL-arginine-p-nitroanilide (BAPNA) and VSC levels in both MG and CP groups, although the deeper residual pockets led to higher AST and VSC levels in the CP group. Within the limits of the present pilot study, it can be concluded that the non-surgical therapy may influence VSC formation in a manner dependent on periodontal disease severity.

Quantification of MDMA and MDA in abusers' hair samples by semi-micro column HPLC with fluorescence detection.

PubMed

Nakamura, Shinichi; Tomita, Mamoru; Wada, Mitsuhiro; Chung, Heesun; Kuroda, Naotaka; Nakashima, Kenichiro

2006-01-01

A sensitive semi-micro column high-performance liquid chromatography with fluorescence detection method was developed for the determination of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MP) and amphetamine (AP) in human hair. 4-(4,5-Diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) and 1-methyl-3-phenylpropylamine were used as labeling reagent and internal standard, respectively. These drugs were extracted from hair into 5% trifluoroacetic acid in methanol, and fluorescent labeled with DIB-Cl. The separation of DIB-derivatives was achieved on a reversed-phase semi-micro ODS column with an acetonitrile-methanol-water (30:40:30, v/v/v%) mixture as a mobile phase. The limits of detection at a signal-to-noise ratio of 3 for MDMA, MDA, MP and AP were 0.25, 0.15, 0.25 and 0.19 ng/mg, respectively. Precision of intra- and inter-day assay as the relative standard deviation were in the range 1.5-6.8% (n = 5) and 2.7-4.7% (n = 5), respectively. The proposed method was highly sensitive and able to detect MDMA and its related compounds in small amounts of hair sample, and could be applied to quantification of six abusers' hair samples. Copyright 2006 John Wiley & Sons, Ltd.

Propionibacterium acnes and antimicrobial resistance in acne.

PubMed

Dessinioti, Clio; Katsambas, Andreas

The human commensal bacterium Propionibacterium acnes (P. acnes) resides in the pilosebaceous duct of the skin. It has been long implicated in the pathogenesis of acne, although its exact role in the development of inflammatory acne lesions and in the formation of the microcomedo in the early stages of acne remains controversial. The worldwide prevalence of antibiotic-resistant P. acnes is increasing, with rates varying in different parts of the world. The reason for the difference in the antibiotic resistance patterns of P. acnes among different countries is not clear, although it may be attributed to different antibiotic prescribing habits, concomitant use of topical agents (retinoids, benzoyl peroxide, or other antibiotics), varying methods of bacterial sampling, or even different P. acnes populations. Although the relative abundances of P. acnes may be similar among patients with acne and individuals without acne, P. acnes populations and the presence of P. acnes biofilms differ, with different potential virulence properties and antimicrobial resistance patterns. Implications of the use of antibiotics and of antimicrobial resistance in patients with acne include the decreased efficacy of antibiotic treatments for acne, and the possible emergence of other resistant bacterial species via selective pressure by antibiotic use. Copyright © 2017 Elsevier Inc. All rights reserved.

Azelaic acid in the treatment of acne in adult females: case reports.

PubMed

Vargas-Diez, E; Hofmann, M A; Bravo, B; Malgazhdarova, G; Katkhanova, O A; Yutskovskaya, Y

2014-01-01

Acne, one of the most common skin problems in dermatological practice, is a condition that affects not only adolescents but also adults. While approximately 80% of cases occurring in adulthood are persistent from teenage years, around 20% are described as 'late-onset' disease, appearing for the first time in adulthood. The disease can be triggered by hormonal changes (including a change from one contraceptive to another), or it can be induced by certain nonhormonal medications, emotional stress, and various underlying diseases such as polycystic ovary syndrome. In many cases acne becomes a chronic skin condition with undulating activity, including improvement and relapse phases, and is often experienced as a major psychological burden. It is, therefore, even more important to provide an effective as well as a safe and tolerable treatment. The spectrum of topical acne treatments has expanded substantially in recent years and various topical medications are available, ranging from azelaic acid, antibiotics, retinoids and benzoyl peroxide to several fixed combinations of these active compounds. The following case collection illustrates how 15% azelaic acid gel, as a well-established monotherapy, can be successfully employed to treat mild-to-moderate forms of adult female acne. © 2013 S. Karger AG, Basel.

Pyrrolidine and Piperidine Formation Via Copper(II) Carboxylate Promoted Intramolecular Carboamination of Unactivated Olefins: Diastereoselectivity and Mechanism

PubMed Central

Sherman, Eric S.; Fuller, Peter H.; Kasi, Dhanalakshmi; Chemler, Sherry R.

2008-01-01

An expanded substrate scope and in depth analysis of the reaction mechanism of the copper(II) carboxylate promoted intramolecular carboamination of unactivated alkenes is described. This method provides access to N-functionalized pyrrolidines and piperidines. Both aromatic and aliphatic γ- and δ-alkenyl N-arylsulfonamides undergo the oxidative cyclization reaction efficiently. N-Benzoyl-2-allylaniline also underwent the oxidative cyclization. The terminal olefin substrates examined were more reactive than those with internal olefins, and the latter terminated in elimination rather than carbon-carbon bond formation. The efficiency of the reaction was enhanced by the use of more organic soluble copper(II) carboxylate salts, copper(II) neodecanoate in particular. The reaction times were reduced by the use of microwave heating. High levels of diastereoselectivity were observed in the synthesis of 2,5-disubstituted pyrrolidines, wherein the cis substitution pattern predominates. The mechanism of the reaction is discussed in the context of the observed reactivity and in comparison to analogous reactions promoted by other reagents and conditions. Our evidence supports a mechanism wherein the N-C bond is formed via intramolecular syn aminocupration and the C-C bond is formed via intramolecular addition of a primary carbon radical to an aromatic ring. PMID:17428100

ATP-Dependent C–F Bond Cleavage Allows the Complete Degradation of 4-Fluoroaromatics without Oxygen

PubMed Central

Tiedt, Oliver; Mergelsberg, Mario; Boll, Kerstin; Müller, Michael; Adrian, Lorenz; Jehmlich, Nico; von Bergen, Martin

2016-01-01

ABSTRACT Complete biodegradation of the abundant and persistent fluoroaromatics requires enzymatic cleavage of an arylic C–F bond, probably the most stable single bond of a biodegradable organic molecule. While in aerobic microorganisms defluorination of fluoroaromatics is initiated by oxygenases, arylic C–F bond cleavage has never been observed in the absence of oxygen. Here, an oxygen-independent enzymatic aryl fluoride bond cleavage is described during the complete degradation of 4-fluorobenzoate or 4-fluorotoluene to CO2 and HF in the denitrifying Thauera aromatica: the ATP-dependent defluorination of 4-fluorobenzoyl-coenzyme A (4-F-BzCoA) to benzoyl-coenzyme A (BzCoA) and HF, catalyzed by class I BzCoA reductase (BCR). Adaptation to growth with the fluoroaromatics was accomplished by the downregulation of a promiscuous benzoate-CoA ligase and the concomitant upregulation of 4-F-BzCoA-defluorinating/dearomatizing BCR on the transcriptional level. We propose an unprecedented mechanism for reductive arylic C–F bond cleavage via a Birch reduction-like mechanism resulting in a formal nucleophilic aromatic substitution. In the proposed anionic 4-fluorodienoyl-CoA transition state, fluoride elimination to BzCoA is favored over protonation to a fluorinated cyclic dienoyl-CoA. PMID:27507824

Benzophenone-type UV filters in surface waters: An assessment of profiles and ecological risks in Shanghai, China.

PubMed

Wu, Ming-Hong; Xie, Deng-Guo; Xu, Gang; Sun, Rui; Xia, Xiao-Yu; Liu, Wen-Long; Tang, Liang

2017-07-01

Benzophenone-type UV filters (BP-UV filters) are frequently introduced into aquatic environment from several sources. The occurrence and fate of select BP-UV filters and their metabolites were investigated in this study. All target compounds were detected in water samples, except for 2, 3, 4-trihydroxybenzophenone (2, 3, 4-OH-BP). The concentration reached up 131ngL -1 for 5-benzoyl-4-hydroxy-2-ethoxybenzenesulfonic acid (BP-4), 30.0ngL -1 for 2-hydroxy-4-methoxybenzophenone (BP-3), and mean value of 158ngL -1 for benzophenone (BP). Concentrations of BP-UV filters were not related to recreational waters but with high population frequencies. In addition, five BP-UV filters, namely 2,2',4,4'-tetrahydroxybenzophenone (BP-2), 2,3,4-OH-BP, 2,4-dihydroxybenzophenone (BP-1), 4-hydroxybenzophenone (4-OH-BP) and BP were investigated for probable sources, and found that they originate from BP-3 metabolism. There is a similar source for BP-3, BP-4, BP-1, 4-OH-BP and BP. Environmental risk assessment (ERA) showed that risk quotients (RQs) of BP-4, BP-3 and BP were 2.7, 0.8 and 0.5, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

Acne vulgaris.

PubMed

Purdy, Sarah; de Berker, David

2011-01-05

Acne vulgaris affects over 80% of teenagers, and persists beyond the age of 25 years in 3% of men and 12% of women. Typical lesions of acne include comedones, inflammatory papules, and pustules. Nodules and cysts occur in more severe acne and can cause scarring and psychological distress. We conducted a systematic review and aimed to answer the following clinical question: What are the effects of topical and oral treatments in people with acne vulgaris? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 69 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: topical treatments (adapalene, azelaic acid, benzoyl peroxide, clindamycin, erythromycin [alone or plus zinc]; isotretinoin, tetracycline, tretinoin); and oral treatments (doxycycline, isotretinoin, lymecycline, minocycline, oxytetracycline, tetracycline).

Mapping of the immunophilin-immunosuppressant site of interaction on calcineurin.

PubMed

Husi, H; Luyten, M A; Zurini, M G

1994-05-13

The interaction of the immunosuppressive complexes cyclosporin A-cyclophilin A and FK506 binding protein-FK506 with the Ca(2+)- and calmodulin-dependent protein phosphatase calcineurin has been investigated by means of photoaffinity labeling and chemical cross-linking. Photolabeling of purified bovine brain calcineurin with the affinity label [O-[4-[4-(1-diazo-2,2,2-trifluoroethyl)benzoyl]aminobutanoyl]-D- serine8]cyclosporin in the presence of cyclophilin A results, in addition to the labeling of cyclophilin itself, in the transfer of some of the chemical probe to both the catalytic subunit A and the regulatory subunit B of calcineurin. Chemical cross-linking studies with disuccinimidyl suberate in the presence of either cyclophilin A, B, or C in complex with cyclosporin A or FK506 binding protein-FK506 result on the other hand in the apparently exclusive and strictly immunosuppressant-dependent formation of covalent immunophilin-calcineurin B subunit products. Cross-linking of immunophilins to calcineurin B subunit requires the presence of subunit A. In the present study, using a set of recombinant maltose-binding protein fusion products representing different stretches of the catalytic subunit A, we were able to map the minimal calcineurin A sequence necessary for immunophilin-ligand-calcineurin B interaction to occur.

Steric and thermodynamic limits of design for the incorporation of large unnatural amino acids in aminoacyl-tRNA synthetase enzymes.

PubMed

Armen, Roger S; Schiller, Stefan M; Brooks, Charles L

2010-06-01

Orthogonal aminoacyl-tRNA synthetase/tRNA pairs from archaea have been evolved to facilitate site specific in vivo incorporation of unnatural amino acids into proteins in Escherichia coli. Using this approach, unnatural amino acids have been successfully incorporated with high translational efficiency and fidelity. In this study, CHARMM-based molecular docking and free energy calculations were used to evaluate rational design of specific protein-ligand interactions for aminoacyl-tRNA synthetases. A series of novel unnatural amino acid ligands were docked into the p-benzoyl-L-phenylalanine tRNA synthetase, which revealed that the binding pocket of the enzyme does not provide sufficient space for significantly larger ligands. Specific binding site residues were mutated to alanine to create additional space to accommodate larger target ligands, and then mutations were introduced to improve binding free energy. This approach was used to redesign binding sites for several different target ligands, which were then tested against the standard 20 amino acids to verify target specificity. Only the synthetase designed to bind Man-alpha-O-Tyr was predicted to be sufficiently selective for the target ligand and also thermodynamically stable. Our study suggests that extensive redesign of the tRNA synthatase binding pocket for large bulky ligands may be quite thermodynamically unfavorable.

Steric and Thermodynamic Limits of Design for the Incorporation of Large UnNatural Amino Acids in Aminoacyl-tRNA Synthetase Enzymes

PubMed Central

Armen, Roger S.; Schiller, Stefan M.; Brooks, Charles L.

2015-01-01

Orthogonal aminoacyl-tRNA synthetase/tRNA pairs from archaea have been evolved to facilitate site specific in vivo incorporation of unnatural amino acids into proteins in Escherichia coli. Using this approach, unnatural amino acids have been successfully incorporated with high translational efficiency and fidelity. In this study, CHARMM-based molecular docking and free energy calculations were used to evaluate rational design of specific protein-ligand interactions for aminoacyl-tRNA synthetases. A series of novel unnatural amino acid ligands were docked into the p-benzoyl-L-phenylalanine tRNA synthetase, which revealed that the binding pocket of the enzyme does not provide sufficient space for significantly larger ligands. Specific binding site residues were mutated to alanine to create additional space to accommodate larger target ligands, and then mutations were introduced to improve binding free energy. This approach was used to redesign binding sites for several different target ligands, which were then tested against the standard 20 amino acids to verify target specificity. Only the synthetase designed to bind Man-α-O-Tyr was predicted to be sufficiently selective for the target ligand and also thermodynamically stable. Our study suggests that extensive redesign of the tRNA synthatase binding pocket for large bulky ligands may be quite thermodynamically unfavorable. PMID:20310065

A study of thermal transitions in a new semicrystalline thermoplastic polyimide

NASA Technical Reports Server (NTRS)

Pratt, J. Richard; St.clair, Terry L.; Gerber, Margaret K.; Gautreaux, Carol R.

1988-01-01

A polyimide derive from 4,4'-isophthaloyl diphthalic anhydride (IDPA) and 1,3-bis (4-aminophenoxy 4'-benzoyl) benzene (1,3-BABB) having semicrystalline behavior was prepared and characterized by differential scanning calorimetry (DSC) and wide angle X-ray scattering (WAXS). Thus a poly(amic acid) film cured in air for one hour each at 100 and 200 C displayed an endotherm at 286 C, followed by a crystallization exotherm at 317 C, and a second melting transition at 350 C. The 286 C melting point appeared to result from earlier solvent-induced crystallization. Films cast from DMAc, air dried, and soaked in methylene chloride could not be induced into semicrystallinity. The fully cured polyimide has a Tg of 216 C. Films heated to temperatures as high as 100 C for one hour in air were transparent and light yellow in color. Those films heated to or above 125 C were translucent. Polarized light microscopy revealed the presence of spherulites 608 micrometers in diameter in a sample cured to 275 C in air. Two film samples, one cured to 275 and the other to 325 C, were evaluated for tensile and ultimate strength, modulus, and percent elongation at 25 and 200 C. These values remained essentially constant at each test temperature.

A combined experimental and theoretical study of the thermal [3+2] cycloaddition of carbonyl ylides with activated alkenes

NASA Astrophysics Data System (ADS)

Hamza-Reguig, Samira; Bentabed-Ababsa, Ghenia; Domingo, Luis R.; Ríos-Gutiérrez, Mar; Philippot, Stéphanie; Fontanay, Stéphane; Duval, Raphaël E.; Ruchaud, Sandrine; Bach, Stéphane; Roisnel, Thierry; Mongin, Florence

2018-04-01

4-Benzoyl-3,5-diaryltetrahydrofuran-2,2-dicarbonitriles were first synthesized from 2,2-dicyano-3-aryloxiranes and chalcones at toluene reflux; the 4,5-cis products proved to be predominantly formed and were isolated. Whereas shortened reaction times were observed by using microwave irradiation or catalytic cuprous chloride, no significant stereoselectivity change was in general noticed. Reacting 2,2-dicyano-3-aryloxiranes with 2-cyclopentenone next afforded 3-aryl-4-oxohexahydro-1H-cyclopenta[c]furan-1,1-dicarbonitriles, and the endo stereoisomers were isolated. That no stereoselectivity change was noticed in the presence of cuprous chloride rather suggests an impact of the salt on the epoxide ring opening. Finally, treatment of 2,2-dicyano-3-aryloxiranes by 2-morpholinoacrylonitrile yielded 3-cyano-3-morpholino-5-phenyltetrahydrofuran-2,2-dicarbonitriles from which the preponderant trans isomers were isolated. Importantly, the molecular mechanism of the domino reaction between 2,2-dicyano-3-phenyloxirane and 2-cyclopentenone was studied. The rate-determining thermal ring opening of the oxirane is followed by a non-concerted pseudoradical-type reaction of the carbonyl ylide with 2-cyclopentenone. Using the bond evolution theory also allowed the regioselectivity of this non-polar reaction to be explained.

Electrolysis of trichloromethylated organic compounds under aerobic conditions catalyzed by the B12 model complex for ester and amide formation.

PubMed

Shimakoshi, Hisashi; Luo, Zhongli; Inaba, Takuya; Hisaeda, Yoshio

2016-06-21

The electrolysis of benzotrichloride at -0.9 V vs. Ag/AgCl in the presence of the B12 model complex, heptamethyl cobyrinate perchlorate, in ethanol under aerobic conditions using an undivided cell equipped with a platinum mesh cathode and a zinc plate anode produced ethylbenzoate in 56% yield with 92% selectivity. The corresponding esters were obtained when the electrolysis was carried out in various alcohols such as methanol, n-propanol, and i-propanol. Benzoyl chloride was detected by GC-MS during the electrolysis as an intermediate for the ester formation. When the electrolysis was carried out under anaerobic conditions, partially dechlorinated products, 1,1,2,2-tetrachloro-1,2-diphenylethane and 1,2-dichlorostilibenes (E and Z forms), were obtained instead of an ester. ESR spin-trapping experiments using 5,5,-dimethylpyrroline N-oxide (DMPO) revealed that the corresponding oxygen-centered radical and carbon-centered radical were steadily generated during the electrolyses under aerobic and anaerobic conditions, respectively. Applications of the aerobic electrolysis to various organic halides, such as substituted benzotrichlorides, are described. Furthermore, the formation of amides with moderate yields by the aerobic electrolysis of benzotrichloride catalyzed by the B12 model complex in the presence of amines in acetonitrile is reported.

Insights on the distribution of substitutions in spruce galactoglucomannan and its derivatives using integrated chemo-enzymatic deconstruction, chromatography and mass spectrometry.

PubMed

Liu, Jun; Leppänen, Ann-Sofie; Kisonen, Victor; Willför, Stefan; Xu, Chunlin; Vilaplana, Francisco

2018-06-01

Accurate determination of the distribution of substitutions in the primary molecular structure of heteropolysaccharides and their derivatives is a prerequisite for their increasing application in the pharmaceutical and biomedical fields, which is unfortunately hindered due to the lack of effective analytical techniques. Acetylated galactoglucomannan (GGM) is an abundant plant polysaccharide as the main hemicellulose in softwoods, and therefore constitutes an important renewable resource from lignocellulosic biomass for the development of bioactive and functional materials. Here we present a methodology for profiling the intramolecular structure of spruce GGM and its chemical derivatives (cationic, anionic, and benzoylated) by combining chemo-enzymatic hydrolysis, liquid chromatography, and mass spectrometry. Fast identification and qualitative mass profiling of GGM and its derivatives was conducted using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS) and electrospray ionization mass spectrometry (ESI-MS). Tandem mass fragmentation analysis and its hyphenation with hydrophilic interaction liquid chromatography (HILIC-ESI-MS/MS) provide further insights on the substitution placement of the GGM oligosaccharides and its derivatives. This method will be useful in understanding the structure-function relationships of native GGM and their derivatives, and therefore facilitate their potential application. Copyright © 2018 Elsevier B.V. All rights reserved.

Acetylcholinesterase and acetylcholine receptor. Final report, 1 April 1992-30 September 1995

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

Cohen, S.G.

1995-10-01

1 Bromo-214Cpinacolone (34CbrPin) inactivates AcChEs, from T. nobiliana labeling Cys 231, and E. electricus labeling His-440, and possibly Trp-435 and Asn-533. 14Cphenacyl bromide, (14CphABr) inactivates, labeling Cys-231 and His-550 in T. nobiliana, and His-550 in E. electricus. Five sequenced peptides in T. nobiliana, are identical with those from T. califomica. Four peptides from E. electricus show 77 - 96% homology. Inactivations by BrPin or PhABr exclude 3Hdfp; inactivation by DFP does not exclude 14CbrPin or 14CphABr. In studies with 14CbrPin, 5-trimethylammonio-2-pentanone was the preferred protecting agent; with 14CphABr, 3-trimethylammonioacetophenone was used with T. nobiliana, phenyltrimethylammonium ion with E. electricus. N-Methylacridiniummore » protects E. electricus against PhABr, but accelerates inactivation of T. nobiliana. Acetylcholine protects E. electricus against PhABr, indicating that His-550 marks the site at which the binding of high concentration of the substrate inhibits its own hydrolysis, possibly important in its action as a neurotransmitter. Photolysis of pivalophenone leading to benzoyl and tert-butyl radicals, inactivates the enzymes. Protection is offered by radical scavenging thiols.« less

Inhibitory effect of vasopressin receptor antagonist OPC-31260 on experimental brain oedema induced by global cerebral ischaemia.

PubMed

Molnár, A H; Varga, C; Berkó, A; Rojik, I; Párducz, A; László, F; László, F A

2008-03-01

The effects of the non-peptide vasopressin V(2) receptor antagonist 5-dimethylamino-1-[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-benzazepine hydrochloride (OPC-31260) on the cerebral oedema induced by general cerebral hypoxia were studied in rats. The general cerebral hypoxia was produced by bilateral common carotid ligation in Sprague-Dawley rats of the CFY strain. By 6 h after the ligation, half of the rats had died, but the survival rate was significantly higher following OPC-31260 administration. Electron microscopic examinations revealed typical ischaemic changes after the carotid ligation. The carotid ligation increased the brain contents of water and Na(+) and enhanced the plasma vasopressin level. The increased brain water and Na(+) accumulation was prevented by OPC-31260 administration, but the plasma vasopressin level was further enhanced by OPC-31260. These results demonstrate the important role of vasopressin in the development of the disturbances in brain water and electrolyte balance in response to general cerebral hypoxia. The carotid ligation-induced cerebral oedema was significantly reduced following oral OPC-31260 administration. The protective mechanism exerted by OPC-31260 stems from its influence on the renal vasopressin V(2) receptors. These observations might suggest an effective approach to the treatment of global hypoxia-induced cerebral oedema in humans.

Canine superficial bacterial folliculitis: current understanding of its etiology, diagnosis and treatment.

PubMed

Bloom, Paul

2014-02-01

Superficial bacterial folliculitis (SBF) is more common in the dog than other mammalian species. Until recently, a successful outcome in cases of canine SBF was possible by administering a potentiated amoxicillin, a first generation cephalosporin or a potentiated sulfonamide. Unfortunately, this predictable susceptibility has changed, because methicillin resistant Staphylococcus pseudintermedius (MRSP) and Staphylococcus aureus (MRSA) are becoming more prevalent in canine SBF cases. The increasing frequency of multidrug resistance complicates the selection of antimicrobial therapy. Antimicrobial agents that were once rarely used in cases of canine SBF, such as amikacin, rifampicin and chloramphenicol, are becoming the drugs of choice, based on bacterial culture and susceptibility testing. Furthermore, changes in antimicrobial susceptibility have helped to re-emphasize the importance of a multimodal approach to treatment of the disease, including topical therapy. Due to the increasing frequency of identification of highly resistant Staphylococcus spp., topical antimicrobial therapy, including the use of diluted sodium hypochlorite (bleach), is becoming necessary to successfully treat some cases of canine SBF. Other important antiseptics that can be used include chlorhexidine, benzoyl peroxide, ethyl lactate, triclosan and boric acid/acetic acid. This review discusses the diagnostic and therapeutic management of canine SBF, with a special emphasis on treating methicillin resistant staphylococcal infections. Copyright © 2013 Elsevier Ltd. All rights reserved.

Formation of a bioconjugate composed of hemin, smectite, and quaternary ammonium chloride that is soluble and active in hydrophobic media.

PubMed

Kurosawa, Masaru; Itoh, Tetsuji; Kodera, Yoh; Matsushima, Ayako; Hiroto, Misao; Nishimura, Hiroyuki; Inada, Yuji

2002-01-01

Hemin (Fe(3+)) was adsorbed onto synthetic smectite (clay mineral) intercalated with a quaternary alkenylammonium compound, dioleyldimethylammonium chloride (DOA), to form a hemin-smectite-DOA conjugate. The hemin-smectite-DOA conjugate was soluble in organic solvents such as benzene and toluene to form a transparent colloidal solution with a light yellow color. Its absorption spectrum in benzene showed two bands, 600 and 568 nm, in the visible region and a sharp Soret band at 400 nm with the molar extinction coefficient of 7.5 x 10(4) M(-1) cm(-1). The formation of the conjugate of smectite and DOA was confirmed by X-ray diffraction analysis: the basal spacing, d(001), of hemin-smectite-DOA conjugate was 19 A which is an expansion of the interlayer space by 5 A based upon the basal spacing of smectite of 14 A. Hemin-smectite-DOA conjugate catalyzed the peroxidase-like reaction in organic solvents using benzoyl peroxide as the hydrogen acceptor and leucocrystal violet as the hydrogen donor. The temperature-dependent peroxidase-like activity of the conjugate was compared with peroxidase activity of horseradish peroxidase. The hemin-smectite-DOA conjugate exhibited higher activity as the temperature was increased from 30 to 70 degrees C, while horseradish peroxidase activity was reduced as the temperature was increased.

Improved Reagents for Newborn Screening of Mucopolysaccharidosis Types I, II, and VI by Tandem Mass Spectrometry

PubMed Central

2015-01-01

Tandem mass spectrometry for the multiplex and quantitative analysis of enzyme activities in dried blood spots on newborn screening cards has emerged as a powerful technique for early assessment of lysosomal storage diseases. Here we report the design and process-scale synthesis of substrates for the enzymes α-l-iduronidase, iduronate-2-sulfatase, and N-acetylgalactosamine-4-sulfatase that are used for newborn screening of mucopolysaccharidosis types I, II, and VI. The products contain a bisamide unit that is hypothesized to readily protonate in the gas phase, which improves detection sensitivity by tandem mass spectrometry. The products contain a benzoyl group, which provides a useful site for inexpensive deuteration, thus facilitating the preparation of internal standards for the accurate quantification of enzymatic products. Finally, the reagents are designed with ease of synthesis in mind, thus permitting scale-up preparation to support worldwide newborn screening of lysosomal storage diseases. The new reagents provide the most sensitive assay for the three lysosomal enzymes reported to date as shown by their performance in reactions using dried blood spots as the enzyme source. Also, the ratio of assay signal to that measured in the absence of blood (background) is superior to all previously reported mucopolysaccharidosis types I, II, and VI assays. PMID:24694010