Putting copper into action: copper-impregnated products with potent biocidal activities.

PubMed

Borkow, Gadi; Gabbay, Jeffrey

2004-11-01

Copper ions, either alone or in copper complexes, have been used for centuries to disinfect liquids, solids, and human tissue. Today copper is used as a water purifier, algaecide, fungicide, nematocide, molluscicide, and antibacterial and antifouling agent. Copper also displays potent antiviral activity. We hypothesized that introducing copper into clothing, bedding, and other articles would provide them with biocidal properties. A durable platform technology has been developed that introduces copper into cotton fibers, latex, and other polymeric materials. This study demonstrates the broad-spectrum antimicrobial (antibacterial, antiviral, antifungal) and antimite activities of copper-impregnated fibers and polyester products. This technology enabled the production of antiviral gloves and filters (which deactivate HIV-1 and other viruses), antibacterial self-sterilizing fabrics (which kill antibiotic-resistant bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci), antifungal socks (which alleviate symptoms of athlete's foot), and anti-dust mite mattress covers (which reduce mite-related allergies). These products did not have skin-sensitizing properties, as determined by guine pig maximization and rabbit skin irritation tests. Our study demonstrates the potential use of copper in new applications. These applications address medical issues of the greatest importance, such as viral transmissions; nosocomial, or healthcare-associated, infections; and the spread of antibiotic-resistant bacteria.

Design, synthesis, and structure-activity relationship study of glycyrrhetinic acid derivatives as potent and selective inhibitors against human carboxylesterase 2.

PubMed

Zou, Li-Wei; Li, Yao-Guang; Wang, Ping; Zhou, Kun; Hou, Jie; Jin, Qiang; Hao, Da-Cheng; Ge, Guang-Bo; Yang, Ling

2016-04-13

Human carboxylesterase 2 (hCE2), one of the major carboxylesterases in the human intestine and various tumour tissues, plays important roles in the oral bioavailability and treatment outcomes of ester- or amide-containing drugs or prodrugs, such as anticancer agents CPT-11 (irinotecan) and LY2334737 (gemcitabine). In this study, 18β-glycyrrhetinic acid (GA), the most abundant pentacyclic triterpenoid from natural source, was selected as a reference compound for the development of potent and specific inhibitors against hCE2. Simple semi-synthetic modulation on GA was performed to obtain a series of GA derivatives. Structure-activity relationship analysis brought novel insights into the structure modification of GA. Converting the 11-oxo-12-ene of GA to 12-diene moiety, and C-3 hydroxyl and C-30 carboxyl group to 3-O-β-carboxypropionyl and ethyl ester respectively, led to a significant enhancement of the inhibitory effect on hCE2 and the selectivity over hCE1. These exciting findings inspired us to design and synthesize the more potent compound 15 (IC50 0.02 μM) as a novel and highly selective inhibitor against hCE2, which was 3463-fold more potent than the parent compound GA and demonstrated excellent selectivity (>1000-fold over hCE1). The molecular docking study of compound 15 and the active site of hCE1 and hCE2 demonstrated that the potent and selective inhibition of compound 15 toward hCE2 could partially be attributed to its relatively stronger interactions with hCE2 than with hCE1. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Covalent Dimer Species of β-Defensin Defr1 Display Potent Antimicrobial Activity against Multidrug-Resistant Bacterial Pathogens▿

PubMed Central

Taylor, Karen; McCullough, Bryan; Clarke, David J.; Langley, Ross J.; Pechenick, Tali; Hill, Adrian; Campopiano, Dominic J.; Barran, Perdita E.; Dorin, Julia R.; Govan, John R. W.

2007-01-01

Beta defensins comprise a family of cationic, cysteine-rich antimicrobial peptides, predominantly expressed at epithelial surfaces. Previously we identified a unique five-cysteine defensin-related peptide (Defr1) that, when synthesized, is a mixture of dimeric isoforms and exhibits potent antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa. Here we report that Defr1 displays antimicrobial activity against an extended panel of multidrug-resistant nosocomial pathogens for which antimicrobial treatment is limited or nonexistent. Defr1 fractions were collected by high-pressure liquid chromatography and analyzed by gel electrophoresis and mass spectrometry. Antimicrobial activity was initially investigated with the type strain Pseudomonas aeruginosa PAO1. All fractions tested displayed equivalent, potent antimicrobial activity levels comparable with that of the unfractionated Defr1. However, use of an oxidized, monomeric six-cysteine analogue (Defr1 Y5C), or of reduced Defr1, gave diminished antimicrobial activity. These results suggest that the covalent dimer structure of Defr1 is crucial to antimicrobial activity; this hypothesis was confirmed by investigation of a synthetic one-cysteine variant (Defr1-1cys). This gave an activity profile similar to that of synthetic Defr1 but only in an oxidized, dimeric form. Thus, we have shown that covalent, dimeric molecules based on the Defr1 β-defensin sequence demonstrate antimicrobial activity even in the absence of the canonical cysteine motif. PMID:17353239

Synthesis and structure-activity relationship of dicationic diaryl ethers as novel potent anti-MRSA and anti-VRE agents.

PubMed

Hu, Laixing; Kully, Maureen L; Boykin, David W; Abood, Norman

2009-08-15

A series of dicationic diaryl ethers have been synthesized and evaluated for in vitro antibacterial activities, including drug resistant bacterial strains. Most of these compounds have shown potent antibacterial activities. Several compounds, such as piperidinyl and thiomorpholinyl compounds 9e and 9l, improved the antimicrobial selectivity and kept potent anti-MRSA and anti-VRE activity. The most potent bis-indole diphenyl ether 19 exhibited anti-MRSA MIC value of 0.06 microg/mL and enhanced antimicrobial selectivity.

Discovery of 2-(3,5-difluoro-4-methylsulfonaminophenyl)propanamides as potent TRPV1 antagonists.

PubMed

Kim, Changhoon; Ann, Jihyae; Lee, Sunho; Sun, Wei; Blumberg, Peter M; Frank-Foltyn, Robert; Bahrenberg, Gregor; Stockhausen, Hannelore; Christoph, Thomas; Lee, Jeewoo

2018-05-23

A series of A-region analogues of 2-(3-fluoro-4-methylsufonamidophenyl) propanamide 1 were investigated as TRPV1 antagonists. The analysis of structure-activity relationship indicated that a fluoro group at the 3- (or/and) 5-position and a methylsulfonamido group at the 4-position were optimal for antagonism of TRPV1 activation by capsaicin. The most potent antagonist 6 not only exhibited potent antagonism of activation of hTRPV1 by capsaicin, low pH and elevated temperature but also displayed highly potent antagonism of activation of rTRPV1 by capsaicin. Further studies demonstrated that antagonist 6 blocked the hypothermic effect of capsaicin in vivo, consistent with its in vitro mechanism, and it showed promising analgesic activity in the formalin animal model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phenylthiazole Antibacterial Agents Targeting Cell Wall Synthesis Exhibit Potent Activity in Vitro and in Vivo against Vancomycin-Resistant Enterococci.

PubMed

Mohammad, Haroon; Younis, Waleed; Chen, Lu; Peters, Christine E; Pogliano, Joe; Pogliano, Kit; Cooper, Bruce; Zhang, Jianan; Mayhoub, Abdelrahman; Oldfield, Eric; Cushman, Mark; Seleem, Mohamed N

2017-03-23

The emergence of antibiotic-resistant bacterial species, such as vancomycin-resistant enterococci (VRE), necessitates the development of new antimicrobials. Here, we investigate the spectrum of antibacterial activity of three phenylthiazole-substituted aminoguanidines. These compounds possess potent activity against VRE, inhibiting growth of clinical isolates at concentrations as low as 0.5 μg/mL. The compounds exerted a rapid bactericidal effect, targeting cell wall synthesis. Transposon mutagenesis suggested three possible targets: YubA, YubB (undecaprenyl diphosphate phosphatase (UPPP)), and YubD. Both UPPP as well as undecaprenyl diphosphate synthase were inhibited by compound 1. YubA and YubD are annotated as transporters and may also be targets because 1 collapsed the proton motive force in membrane vesicles. Using Caenorhabditis elegans, we demonstrate that two compounds (1, 3, at 20 μg/mL) retain potent activity in vivo, significantly reducing the burden of VRE in infected worms. Taken altogether, the results indicate that compounds 1 and 3 warrant further investigation as novel antibacterial agents against drug-resistant enterococci.

4-substituted cyclohexyl sulfones as potent, orally active gamma-secretase inhibitors.

PubMed

Churcher, Ian; Beher, Dirk; Best, Jonathan D; Castro, José L; Clarke, Earl E; Gentry, Amy; Harrison, Timothy; Hitzel, Laure; Kay, Euan; Kerrad, Sonia; Lewis, Huw D; Morentin-Gutierrez, Pablo; Mortishire-Smith, Russell; Oakley, Paul J; Reilly, Michael; Shaw, Duncan E; Shearman, Mark S; Teall, Martin R; Williams, Susie; Wrigley, Jonathan D J

2006-01-15

The protease gamma-secretase plays a pivotal role in the synthesis of pathogenic amyloid-beta in Alzheimer's disease (AD). Here, we report a further extension to a series of cyclohexyl sulfone-based gamma-secretase inhibitors which has allowed the preparation of highly potent compounds which also demonstrate robust Abeta(40) lowering in vivo (e.g., compound 32, MED 1mg/kg p.o. in APP-YAC mice).

Potent antiplatelet activity of sesamol in an in vitro and in vivo model: pivotal roles of cyclic AMP and p38 mitogen-activated protein kinase.

PubMed

Chang, Chao C; Lu, Wan J; Chiang, Cheng W; Jayakumar, Thanasekaran; Ong, Eng T; Hsiao, George; Fong, Tsorng H; Chou, Duen S; Sheu, Joen R

2010-12-01

Sesamol is a potent phenolic antioxidant which possesses antimutagenic, antihepatotoxic and antiaging properties. Platelet activation is relevant to a variety of acute thrombotic events and coronary heart diseases. There have been few studies on the effect of sesamol on platelets. Therefore, the aim of this study was to systematically examine the detailed mechanisms of sesamol in preventing platelet activation in vitro and in vivo. Sesamol (2.5-5 μM) exhibited more potent activity of inhibiting platelet aggregation stimulated by collagen than other agonists. Sesamol inhibited collagen-stimulated platelet activation accompanied by [Ca(2+)](i) mobilization, thromboxane A(2) (TxA(2)) formation, and phospholipase C (PLC)γ2, protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) phosphorylation in washed platelets. Sesamol markedly increased cAMP and cGMP levels, endothelial nitric oxide synthase (eNOS) expression and NO release, as well as vasodilator-stimulated phosphoprotein (VASP) phosphorylation. SQ22536, an inhibitor of adenylate cyclase, markedly reversed the sesamol-mediated inhibitory effects on platelet aggregation and p38 MAPK phosphorylation, and sesamol-mediated stimulatory effects on VASP and eNOS phosphorylation, and NO release. Sesamol also reduced hydroxyl radical (OH(●)) formation in platelets. In an in vivo study, sesamol (5 mg/kg) significantly prolonged platelet plug formation in mice. The most important findings of this study demonstrate for the first time that sesamol possesses potent antiplatelet activity, which may involve activation of the cAMP-eNOS/NO-cGMP pathway, resulting in inhibition of the PLCγ2-PKC-p38 MAPK-TxA(2) cascade, and, finally, inhibition of platelet aggregation. Sesamol treatment may represent a novel approach to lowering the risk of or improving function in thromboembolism-related disorders. Copyright © 2010 Elsevier Inc. All rights reserved.

Synthesis and potent in vitro activity of novel 1H-benzimidazoles as anti-MRSA agents.

PubMed

Karataş, Hacer; Alp, Mehmet; Yildiz, Sulhiye; Göker, Hakan

2012-08-01

A new class of 1H-benzimidazolecarboxamidines was synthesized and evaluated for in vitro antibacterial and antifungal activities, including drug-resistant bacterial strains. The most potent compound (32) has the same ratio of anti-MRSA activity as Vancomycin (minimal inhibitory concentrations value 0.78 μg/mL). The mechanism of action for 1H-benzimidazolecarboxamidine appears to be different from existing antibacterial agents. These compounds have potential for development as a new class of potent anti-MRSA agent. © 2012 John Wiley & Sons A/S.

Identification and Characterization of the First Cathelicidin from Sea Snakes with Potent Antimicrobial and Anti-inflammatory Activity and Special Mechanism*

PubMed Central

Wei, Lin; Gao, Jiuxiang; Zhang, Shumin; Wu, Sijin; Xie, Zeping; Ling, Guiying; Kuang, Yi-Qun; Yang, Yongliang; Yu, Haining; Wang, Yipeng

2015-01-01

Cathelicidins are a family of gene-encoded peptide effectors of innate immunity found exclusively in vertebrates. They play pivotal roles in host immune defense against microbial invasions. Dozens of cathelicidins have been identified from several vertebrate species. However, no cathelicidin from marine reptiles has been characterized previously. Here we report the identification and characterization of a novel cathelicidin (Hc-CATH) from the sea snake Hydrophis cyanocinctus. Hc-CATH is composed of 30 amino acids, and the sequence is KFFKRLLKSVRRAVKKFRKKPRLIGLSTLL. Circular dichroism spectroscopy and structure modeling analysis indicated that Hc-CATH mainly assumes an amphipathic α-helical conformation in bacterial membrane-mimetic solutions. It possesses potent broad-spectrum and rapid antimicrobial activity. Meanwhile, it is highly stable and shows low cytotoxicity toward mammalian cells. The microbial killing activity of Hc-CATH is executed through the disruption of cell membrane and lysis of bacterial cells. In addition, Hc-CATH exhibited potent anti-inflammatory activity by inhibiting the LPS-induced production of nitric oxide (NO) and pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Hc-CATH directly binds with LPS to neutralize its toxicity, and it also binds to Toll-like receptor 4 (TLR4/MD2 complex), which therefore inhibits the binding of LPS to TLR4/MD2 complex and the subsequent activation of LPS-induced inflammatory response pathways. Taken together, our study demonstrates that Hc-CATH, the first cathelicidin from sea snake discovered to have both antimicrobial and anti-inflammatory activity, is a potent candidate for the development of peptide antibiotics. PMID:26013823

Benzil, a potent activator of microsomal epoxide hydrolase in vitro.

PubMed

Seidegård, J; DePierre, J W

1980-12-01

Benzil was found to be a very potent activator of microsomal epoxide hydrolase activity (measured with styrene oxide as substrate) in vitro. The activating effect was uncompetitive and benzil causes approximately ninefold increases in both the apparent V and the apparent Km of the enzyme(s). The half-maximal effect on activity was obtained as a 0.3 mM concentration of benzil. The activating effect obtained with benzil was found to be very specific, since a variety of structurally related compounds had little or no effect on microsomal epoxide hydrolase activity. In order to obtain indications for the existence of more than one microsomal epoxide hydrolase the effect of benzil on this activity from rats induced with phenobarbital, 3-methylcholanthrene, 2-acetylaminofluorene, trans-stilbene oxide, and benzil was tested. The differences observed were minor.

Structural analysis of proanthocyanidins isolated from fruit stone of Chinese hawthorn with potent antityrosinase and antioxidant activity.

PubMed

Chai, Wei-Ming; Chen, Chih-Min; Gao, Yu-Sen; Feng, Hui-Ling; Ding, Yu-Mei; Shi, Yan; Zhou, Han-Tao; Chen, Qing-Xi

2014-01-08

Proanthocyanidins were isolated from fruit stone of Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.). Their structures were analyzed and elucidated by methods of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS). The results demonstrated that these compounds are complicated mixtures of homo- and heteropolymers consisting of procyanidin/procyanidin gallate and prodelphinidin. They possessed structural heterogeneity in monomer units, polymer length, and interflavan linkage (A-type and B-type). Their antityrosinase and antioxidant activity were then investigated. The results revealed that they can inhibit tyrosinase activities, including the monophenolase activity and the diphenolase activity. In addition, proanthocyanidins possessed potent antioxidant activity. Our studies revealed that proanthocyanidins isolated from fruit stone of Chinese hawthorn may be applied in food, agriculture, pharmaceutical, and cosmetic industries.

Extensive screening for herbal extracts with potent antioxidant properties

PubMed Central

Niwano, Yoshimi; Saito, Keita; Yoshizaki, Fumihiko; Kohno, Masahiro; Ozawa, Toshihiko

2011-01-01

This paper summarizes our research for herbal extracts with potent antioxidant activity obtained from a large scale screening based on superoxide radical (O2•−) scavenging activity followed by characterization of antioxidant properties. Firstly, scavenging activity against O2•− was extensively screened from ethanol extracts of approximately 1000 kinds of herbs by applying an electron spin resonance (ESR)-spin trapping method, and we chose four edible herbal extracts with prominently potent ability to scavenge O2•−. They are the extracts from Punica granatum (Peel), Syzygium aromaticum (Bud), Mangifera indica (Kernel), and Phyllanthus emblica (Fruit). These extracts were further examined to determine if they also scavenge hydroxyl radical (•OH), by applying the ESR spin-trapping method, and if they have heat resistance as a desirable characteristic feature. Experiments with the Fenton reaction and photolysis of H2O2 induced by UV irradiation demonstrated that all four extracts have potent ability to directly scavenge •OH. Furthermore, the scavenging activities against O2•− and •OH of the extracts of P. granatum (peel), M. indica (kernel) and P. emblica (fruit) proved to be heat-resistant. The results of the review might give useful information when choosing a potent antioxidant as a foodstuff. For instance, the four herbal extracts chosen from extensive screening possess desirable antioxidant properties. In particular, the extracts of the aforementioned three herbs are expected to be suitable for food processing in which thermal devices are used, because of their heat resistance. PMID:21297917

Design of a potent antibiotic peptide based on the active region of human defensin 5.

PubMed

Wang, Cheng; Shen, Mingqiang; Gohain, Neelakshi; Tolbert, William D; Chen, Fang; Zhang, Naixin; Yang, Ke; Wang, Aiping; Su, Yongping; Cheng, Tianmin; Zhao, Jinghong; Pazgier, Marzena; Wang, Junping

2015-04-09

Human defensin 5 (HD5) is a broad-spectrum antibacterial peptide with a C-terminal active region. To promote the development of this peptide into an antibiotic, we initially substituted Glu21 with Arg because it is an electronegative residue located around the active region. Although detrimental to dimer formation, the E21R substitution markedly enhanced the antibacterial activity of HD5 and increased its ability to penetrate cell membranes, demonstrating that increasing the electropositive charge compensated for the effect of dimer disruption. Subsequently, a partial Arg scanning mutagenesis was performed, and Thr7 was selected for replacement with Arg to further strengthen the antibacterial activity. The newly designed peptide, T7E21R-HD5, exhibited potent antibacterial activity, even in saline and serum solutions. In contrast to monomeric E21R-HD5, T7E21R-HD5 assembled into an atypical dimer with parallel β strands, thus expanding the role of increasing electropositive charge in bactericidal activity and providing a useful guide for further defensin-derived antibiotic design.

The Bruton Tyrosine Kinase (BTK) Inhibitor Acalabrutinib Demonstrates Potent On-Target Effects and Efficacy in Two Mouse Models of Chronic Lymphocytic Leukemia.

PubMed

Herman, Sarah E M; Montraveta, Arnau; Niemann, Carsten U; Mora-Jensen, Helena; Gulrajani, Michael; Krantz, Fanny; Mantel, Rose; Smith, Lisa L; McClanahan, Fabienne; Harrington, Bonnie K; Colomer, Dolors; Covey, Todd; Byrd, John C; Izumi, Raquel; Kaptein, Allard; Ulrich, Roger; Johnson, Amy J; Lannutti, Brian J; Wiestner, Adrian; Woyach, Jennifer A

2017-06-01

Purpose: Acalabrutinib (ACP-196) is a novel, potent, and highly selective Bruton tyrosine kinase (BTK) inhibitor, which binds covalently to Cys481 in the ATP-binding pocket of BTK. We sought to evaluate the antitumor effects of acalabrutinib treatment in two established mouse models of chronic lymphocytic leukemia (CLL). Experimental Design: Two distinct mouse models were used, the TCL1 adoptive transfer model where leukemic cells from Eμ-TCL1 transgenic mice are transplanted into C57BL/6 mice, and the human NSG primary CLL xenograft model. Mice received either vehicle or acalabrutinib formulated into the drinking water. Results: Utilizing biochemical assays, we demonstrate that acalabrutinib is a highly selective BTK inhibitor as compared with ibrutinib. In the human CLL NSG xenograft model, treatment with acalabrutinib demonstrated on-target effects, including decreased phosphorylation of PLCγ2, ERK, and significant inhibition of CLL cell proliferation. Furthermore, tumor burden in the spleen of the mice treated with acalabrutinib was significantly decreased compared with vehicle-treated mice. Similarly, in the TCL1 adoptive transfer model, decreased phosphorylation of BTK, PLCγ2, and S6 was observed. Most notably, treatment with acalabrutinib resulted in a significant increase in survival compared with mice receiving vehicle. Conclusions: Treatment with acalabrutinib potently inhibits BTK in vivo , leading to on-target decreases in the activation of key signaling molecules (including BTK, PLCγ2, S6, and ERK). In two complementary mouse models of CLL, acalabrutinib significantly reduced tumor burden and increased survival compared with vehicle treatment. Overall, acalabrutinib showed increased BTK selectivity compared with ibrutinib while demonstrating significant antitumor efficacy in vivo on par with ibrutinib. Clin Cancer Res; 23(11); 2831-41. ©2016 AACR . ©2016 American Association for Cancer Research.

Molecular design and structure--activity relationships leading to the potent, selective, and orally active thrombin active site inhibitor BMS-189664.

PubMed

Das, Jagabandhu; Kimball, S David; Hall, Steven E; Han, Wen Ching; Iwanowicz, Edwin; Lin, James; Moquin, Robert V; Reid, Joyce A; Sack, John S; Malley, Mary F; Chang, Chiehying Y; Chong, Saeho; Wang-Iverson, David B; Roberts, Daniel G M; Seiler, Steven M; Schumacher, William A; Ogletree, Martin L

2002-01-07

A series of structurally novel small molecule inhibitors of human alpha-thrombin was prepared to elucidate their structure-activity relationships (SARs), selectivity and activity in vivo. BMS-189664 (3) is identified as a potent, selective, and orally active reversible inhibitor of human alpha-thrombin which is efficacious in vivo in a mouse lethality model, and at inhibiting both arterial and venous thrombosis in cynomolgus monkey models.

The Bruton’s tyrosine kinase (BTK) inhibitor acalabrutinib demonstrates potent on-target effects and efficacy in two mouse models of chronic lymphocytic leukemia

PubMed Central

Herman, Sarah E. M.; Montraveta, Arnau; Niemann, Carsten U.; Mora-Jensen, Helena; Gulrajani, Michael; Krantz, Fanny; Mantel, Rose; Smith, Lisa L.; McClanahan, Fabienne; Harrington, Bonnie K.; Colomer, Dolors; Covey, Todd; Byrd, John C.; Izumi, Raquel; Kaptein, Allard; Ulrich, Roger; Johnson, Amy J.; Lannutti, Brian J.; Wiestner, Adrian; Woyach, Jennifer A.

2017-01-01

Purpose Acalabrutinib (ACP-196) is a novel, potent, and highly selective BTK inhibitor, which binds covalently to Cys481 in the ATP-binding pocket of BTK. We sought to evaluate the anti-tumor effects of acalabrutinib treatment in two established mouse models of chronic lymphocytic leukemia (CLL). Experimental Design Two distinct mouse models were used, the TCL1 adoptive transfer model where leukemic cells from Eμ-TCL1 transgenic mice are transplanted into C57BL/6 mice, and the human NSG primary CLL xenograft model. Mice received either vehicle or acalabrutinib formulated into the drinking water. Results Utilizing biochemical assays we demonstrate that acalabrutinib is a highly selective BTK inhibitor as compared to ibrutinib. In the human CLL NSG xenograft model, treatment with acalabrutinib demonstrated on-target effects including decreased phosphorylation of PLCγ2, ERK and significant inhibition of CLL cell proliferation. Further, tumor burden in the spleen of the mice treated with acalabrutinib was significantly decreased compared to vehicle treated mice. Similarly, in the TCL1 adoptive transfer model, decreased phosphorylation of BTK, PLCγ2 and S6 was observed. Most notably, treatment with acalabrutinib resulted in a significant increase in survival compared to mice receiving vehicle. Conclusions Treatment with acalabrutinib potently inhibits BTK in vivo, leading to on-target decreases in the activation of key signaling molecules (including BTK, PLCγ2, S6 and ERK). In two complementary mouse models of CLL acalabrutinib significantly reduced tumor burden and increased survival compared to vehicle treatment. Overall, acalabrutinib showed increased BTK selectivity compared to ibrutinib while demonstrating significant anti-tumor efficacy in vivo on par with ibrutinib. PMID:27903679

Designed, synthetically accessible bryostatin analogues potently induce activation of latent HIV reservoirs in vitro

NASA Astrophysics Data System (ADS)

Dechristopher, Brian A.; Loy, Brian A.; Marsden, Matthew D.; Schrier, Adam J.; Zack, Jerome A.; Wender, Paul A.

2012-09-01

Bryostatin is a unique lead in the development of potentially transformative therapies for cancer, Alzheimer's disease and the eradication of HIV/AIDS. However, the clinical use of bryostatin has been hampered by its limited supply, difficulties in accessing clinically relevant derivatives, and side effects. Here, we address these problems through the step-economical syntheses of seven members of a new family of designed bryostatin analogues using a highly convergent Prins-macrocyclization strategy. We also demonstrate for the first time that such analogues effectively induce latent HIV activation in vitro with potencies similar to or better than bryostatin. Significantly, these analogues are up to 1,000-fold more potent in inducing latent HIV expression than prostratin, the current clinical candidate for latent virus induction. This study provides the first demonstration that designed, synthetically accessible bryostatin analogues could serve as superior candidates for the eradication of HIV/AIDS through induction of latent viral reservoirs in conjunction with current antiretroviral therapy.

A targeted IL-15 fusion protein with potent anti-tumor activity

PubMed Central

Chen, Siqi; Huang, Qiang; Liu, Jiayu; Xing, Jieyu; Zhang, Ning; Liu, Yawei; Wang, Zhong; Li, Qing

2015-01-01

IL-15 has been actively investigated for its potential in tumor immunotherapy. To enhance the anti-tumor activity of IL-15, the novel PFC-1 construct was designed, which comprises the following 3 parts: (1) IL-15Rα fused with IL-15 to enhance IL-15 activity, (2) an Fc fragment to increase protein half-life, and (3) an integrin-targeting RGD peptide to enhance tumor targeting. PFC-1 showed tumor cell targeting without compromising IL-15 activity. PFC-1 also had potent anti-tumor activities in xenograft models, suggesting the potential application of this multi-functional fusion protein in tumor therapy. PMID:26176990

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

PubMed

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

2016-02-26

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

Novel tetrahydrocarbazole benzyl pyridine hybrids as potent and selective butryl cholinesterase inhibitors with neuroprotective and β-secretase inhibition activities.

PubMed

Ghobadian, Roshanak; Mahdavi, Mohammad; Nadri, Hamid; Moradi, Alireza; Edraki, Najmeh; Akbarzadeh, Tahmineh; Sharifzadeh, Mohammad; Bukhari, Syed Nasir Abbas; Amini, Mohsen

2018-05-23

Butyrylcholinesterase (BuChE) inhibitors have become interesting target for treatment of Alzheimer's disease (AD). A series of dual binding site BuChE inhibitors were designed and synthesized based on 2,3,4,9-tetrahydro-1H-carbazole attached benzyl pyridine moieties. In-vitro assay revealed that all of the designed compounds were selective and potent BuChE inhibitors. The most potent BuChE inhibitor was compound 6i (IC 50  = 0.088 ± 0.0009 μM) with the mixed-type inhibition. Docking study revealed that 6i is a dual binding site BuChE inhibitor. Also, Pharmacokinetic properties for 6i were accurate to Lipinski's rule. In addition, compound 6i demonstrated neuroprotective and β-secretase (BACE1) inhibition activities. This compound could also inhibit AChE-induced and self-induced Aβ peptide aggregation at concentration of 100 μM and 10 μM respectively. Generally, the results are presented as new potent selective BuChE inhibitors with a therapeutic potential for the treatment of AD. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A sulforaphane analogue that potently activates the Nrf2-dependent detoxification pathway.

PubMed

Morimitsu, Yasujiro; Nakagawa, Yoko; Hayashi, Kazuhiro; Fujii, Hiroyuki; Kumagai, Takeshi; Nakamura, Yoshimasa; Osawa, Toshihiko; Horio, Fumihiko; Itoh, Ken; Iida, Katsuyuki; Yamamoto, Masayuki; Uchida, Koji

2002-02-01

Exposure of cells to a wide variety of chemoprotective compounds confers resistance to a broad set of carcinogens. For a subset of the chemoprotective compounds, protection is generated by an increase in the abundance of the protective phase II detoxification enzymes, such as glutathione S-transferase (GST). We have recently developed a cell culture system, using rat liver epithelial RL 34 cells, that potently responds to the phenolic antioxidants resulting in the induction of GST activity (Kawamoto, Y., Nakamura, Y., Naito, Y., Torii, Y., Kumagai, T., Osawa, T., Ohigashi, H., Satoh, K., Imagawa, M., and Uchida, K. (2000) J. Biol. Chem. 275, 11291-11299.) In the present study, we investigated the phase II-inducing potency of an isothiocyanate compound in vitro and in vivo and examined a possible induction mechanism. Based on an extensive screening of vegetable extracts for GST inducer activity in RL34 cells, we found Japanese horseradish, wasabi (Wasabia japonica, syn. Eutrema wasabi), as the richest source and identified 6-methylsulfinylhexyl isothiocyanate (6-HITC), an analogue of sulforaphane (4-methylsulfinylbutyl isothiocyanate) isolated from broccoli, as the major GST inducer in wasabi. 6-HITC potently induced both class alpha GSTA1 and class pi GSTP1 isozymes in RL34 cells. In animal experiments, we found that 6-MSHI was rapidly absorbed into the body and induced hepatic phase II detoxification enzymes more potently than sulforaphane. The observations that (i) 6-HITC activated the antioxidant response element (ARE), (ii) 6-HITC induced nuclear localization of the transcription factor Nrf2 that binds to ARE, and (iii) the induction of phase II enzyme genes by 6-HITC was completely abrogated in the nrf2-deficient mice, suggest that 6-HITC is a potential activator of the Nrf2/ARE-dependent detoxification pathway.

A novel pyrazolo[1,5-a]pyrimidine is a potent inhibitor of cyclin-dependent protein kinases 1, 2, and 9, which demonstrates antitumor effects in human tumor xenografts following oral administration.

PubMed

Heathcote, Dean A; Patel, Hetal; Kroll, Sebastian H B; Hazel, Pascale; Periyasamy, Manikandan; Alikian, Mary; Kanneganti, Seshu K; Jogalekar, Ashutosh S; Scheiper, Bodo; Barbazanges, Marion; Blum, Andreas; Brackow, Jan; Siwicka, Alekasandra; Pace, Robert D M; Fuchter, Matthew J; Snyder, James P; Liotta, Dennis C; Freemont, Paul S; Aboagye, Eric O; Coombes, R Charles; Barrett, Anthony G M; Ali, Simak

2010-12-23

Cyclin-dependent protein kinases (CDKs) are central to the appropriate regulation of cell proliferation, apoptosis, and gene expression. Abnormalities in CDK activity and regulation are common features of cancer, making CDK family members attractive targets for the development of anticancer drugs. Here, we report the identification of a pyrazolo[1,5-a]pyrimidine derived compound, 4k (BS-194), as a selective and potent CDK inhibitor, which inhibits CDK2, CDK1, CDK5, CDK7, and CDK9 (IC₅₀= 3, 30, 30, 250, and 90 nmol/L, respectively). Cell-based studies showed inhibition of the phosphorylation of CDK substrates, Rb and the RNA polymerase II C-terminal domain, down-regulation of cyclins A, E, and D1, and cell cycle block in the S and G₂/M phases. Consistent with these findings, 4k demonstrated potent antiproliferative activity in 60 cancer cell lines tested (mean GI₅₀= 280 nmol/L). Pharmacokinetic studies showed that 4k is orally bioavailable, with an elimination half-life of 178 min following oral dosing in mice. When administered at a concentration of 25 mg/kg orally, 4k inhibited human tumor xenografts and suppressed CDK substrate phosphorylation. These findings identify 4k as a novel, potent CDK selective inhibitor with potential for oral delivery in cancer patients.

Discovery of potent peptide-mimetic antagonists for the human thrombin receptor, protease-activated receptor-1 (PAR-1).

PubMed

Maryanoff, Bruce E; Zhang, Han-Cheng; Andrade-Gordon, Patricia; Derian, Claudia K

2003-03-01

Protease-activated receptors (PARs) represent a unique family of seven-transmembrane G-protein-coupled receptors, which are enzymatically cleaved to expose a new extracellular N-terminus that acts as a tethered activating ligand. PAR-1 is cleaved and activated by the serine protease alpha-thrombin, is expressed in various tissues (e.g. platelets and vascular cells), and is involved in cellular responses associated with hemostasis, proliferation, and tissue injury. By using a de novo design approach, we have discovered a series of potent heterocycle-based peptide-miimetic antagonists of PAR-1, exemplified by advanced leads RWJ-56110 (22) and RWJ-58259 (32). These compounds are potent, selective PAR-1 antagonists, devoid of PAR-1 agonist and thrombin inhibitory activity: they bind to PAR-1, interfere with calcium mobilization and cellular functions associated with PAR-1, and do not affect PAR-2, PAR-3, or PAR-4. RWJ-56110 was determined to be a direct inhibitor of PAR-1 activation and internalization, without affecting PAR-1 N-terminal cleavage. At high concentrations of alpha-thrombin, RWJ-56110 fully blocked activation responses in human vascular cells, but not in human platelets; whereas, at high concentrations of TRAP-6, RWJ-56110 blocked activation responses in both cell types. This result is consistent with the presence of another thrombin receptor on human platelets, namely PAR-4. RWJ-56110 and RWJ-58259 clearly interrupt the binding of a tethered ligand to its receptor. RWJ-58259 demonstrated antirestenotic activity in a rat balloon angioplasty model and antithrombotic activity in a cynomolgus monkey arterial injury model. Such PAR-1 antagonists should not only serve as useful tools to delineate the physiological and pathophysiological roles of PAR-1, but also may have therapeutic potential for treating thrombosis and restenosis in humans.

METHYLATION INACTIVATES PENTAVALENT ARSENIC SPECIES BUT ACTIVATES TRIVALENT ARSENIC SPECIES TO POTENT GENOTOXICANTS

EPA Science Inventory

Methylation Inactivates Pentavalent Arsenic Species but Activates Trivalent Arsenic Species to Potent Genotoxicants

The sensitivity ofhumans to arsenic-induced cancer is thought to be related in part to the limited ability of humans to detoxify arsenic. Recently, methyl- ...

Characterization of SB-271046: A potent, selective and orally active 5-HT6 receptor antagonist

PubMed Central

Routledge, Carol; Bromidge, Steven M; Moss, Stephen F; Price, Gary W; Hirst, Warren; Newman, Helen; Riley, Graham; Gager, Tracey; Stean, Tania; Upton, Neil; Clarke, Stephen E; Brown, Anthony M; Middlemiss, Derek N

2000-01-01

SB-271046, potently displaced [3H]-LSD and [125I]-SB-258585 from human 5-HT6 receptors recombinantly expressed in HeLa cells in vitro (pKi 8.92 and 9.09 respectively). SB-271046 also displaced [125I]-SB-258585 from human caudate putamen and rat and pig striatum membranes (pKi 8.81, 9.02 and 8.55 respectively). SB-271046 was over 200 fold selective for the 5-HT6 receptor vs 55 other receptors, binding sites and ion channels. In functional studies on human 5-HT6 receptors SB-271046 competitively antagonized 5-HT-induced stimulation of adenylyl cyclase activity with a pA2 of 8.71. SB-271046 produced an increase in seizure threshold over a wide-dose range in the rat maximal electroshock seizure threshold (MEST) test, with a minimum effective dose of ⩽0.1 mg kg−1 p.o. and maximum effect at 4 h post-dose. The level of anticonvulsant activity achieved correlated well with the blood concentrations of SB-271046 (EC50 of 0.16 μM) and brain concentrations of 0.01–0.04 μM at Cmax. These data, together with the observed anticonvulsant activity of other selective 5-HT6 receptor antagonists, SB-258510 (10 mg kg−1, 2–6 h pre-test) and Ro 04-6790 (1–30 mg kg−1, 1 h pre-test), in the rat MEST test, suggest that the anticonvulsant properties of SB-271046 are likely to be mediated by 5-HT6 receptors. Overall, these studies demonstrate that SB-271046 is a potent and selective 5-HT6 receptor antagonist and is orally active in the rat MEST test. SB-271046 represents a valuable tool for evaluating the in vivo central function of 5-HT6 receptors. PMID:10928964

A potential endogenous ligand for the aryl hydrocarbon receptor has potent agonist activity in vitro and in vivo.

PubMed

Henry, E C; Bemis, J C; Henry, O; Kende, A S; Gasiewicz, T A

2006-06-01

The aryl hydrocarbon receptor (AhR) is best known as a mediator of toxicity of a diverse family of xenobiotic chemicals such as dioxins and PCBs. However, many naturally occurring compounds also activate AhR. One such compound, 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), was isolated from tissue and found to be potent in preliminary tests [J. Song, M. Clagett-Dame, R.E. Peterson, M.E. Hahn, W.M. Westler, R.R. Sicinski, H.F. DeLuca, Proc. Natl. Acad. Sci. USA 99 (2002) 14694-14699]. We have synthesized ITE and [(3)H]ITE and further evaluated its AhR activity in several in vitro and in vivo assays in comparison with the toxic ligand, TCDD. AhR in Hepa1c1c7 cell cytosol bound [(3)H]ITE with high affinity and the AhR.ITE complex formed in vitro bound dioxin response element (DRE) oligonucleotide as potently as TCDD.AhR. In cells treated with ITE, nuclear translocation of AhR, and induction of CYP1A1 protein and of a DRE-dependent luciferase reporter gene were observed. ITE administered to pregnant DRE-LacZ transgenic mice activated fetal AhR, observed as X-gal staining in the same sites as in TCDD-treated mice. However, unlike TCDD, ITE did not induce cleft palate or hydronephrosis. TCDD but not ITE induced thymic atrophy in young adult mice, but both ITE and TCDD caused similar loss of cells and alterations of cell profiles in cultured fetal thymi. These data demonstrate that ITE is a potent AhR agonist in cell extracts, cultured cells, and intact animals, but does not cause the toxicity associated with the more stable xenobiotic ligand, TCDD.

Antibody-Dependent Cell-Mediated Cytotoxicity Effector-Enhanced EphA2 Agonist Monoclonal Antibody Demonstrates Potent Activity against Human Tumors1

PubMed Central

Bruckheimer, Elizabeth M; Fazenbaker, Christine A; Gallagher, Sandra; Mulgrew, Kathy; Fuhrmann, Stacy; Coffman, Karen T; Walsh, William; Ready, Shannon; Cook, Kim; Damschroder, Melissa; Kinch, Michael; Kiener, Peter A; Woods, Rob; Gao, Changshou; Dall'Acqua, William; Wu, Herren; Coats, Steven

2009-01-01

EphA2 is a receptor tyrosine kinase that has been shown to be overexpressed in a variety of human tumor types. Previous studies demonstrated that agonist monoclonal antibodies targeting EphA2 induced the internalization and degradation of the receptor, thereby abolishing its oncogenic effects. In this study, the in vitro and in vivo antibody-dependent cell-mediated cytotoxicity (ADCC) activity of EphA2 effector-enhanced agonist monoclonal antibodies was evaluated. With tumor cell lines and healthy human peripheral blood monocytes, the EphA2 antibodies demonstrated ∼80% tumor cell killing. In a dose-dependent manner, natural killer (NK) cells were required for the in vitro ADCC activity and became activated as demonstrated by the induction of cell surface expression of CD107a. To assess the role of NK cells on antitumor efficacy in vivo, the EphA2 antibodies were evaluated in xenograft models in severe compromised immunodeficient (SCID) mice (which have functional NK cells and monocytes) and SCID nonobese diabetic (NOD) mice (which largely lack functional NK cells and monocytes). Dosing of EphA2 antibody in the SCID murine tumor model resulted in a 6.2-fold reduction in tumor volume, whereas the SCID/nonobese diabetic model showed a 1.6-fold reduction over the isotype controls. Together, these results demonstrate that the anti-EphA2 monoclonal antibodies may function through at least two mechanisms of action: EphA2 receptor activation and ADCC-mediated activity. These novel EphA2 monoclonal antibodies provide additional means by which host effector mechanisms can be activated for selective destruction of EphA2-expressing tumor cells. PMID:19484140

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation.

PubMed

Lekowski, R; Collard, C D; Reenstra, W R; Stahl, G L

2001-02-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O(2), 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 +/- 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (< or = 100 micromol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC(50) = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC(50) approximately 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress.

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation

PubMed Central

Lekowski, Robert; Collard, Charles D.; Reenstra, Wende R.; Stahl, Gregory L.

2001-01-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O2, 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 ± 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (≤ 100 μmol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC50 = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC50 ≈ 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress. PMID:11266613

The preclinical biology of a new potent and selective progestin: trimegestone.

PubMed

Winneker, Richard C; Bitran, Daniel; Zhang, Zhiming

2003-11-01

Trimegestone (TMG) is a 19-norpregnane progestin being developed, in combination with an estrogen, for the treatment of postmenopausal symptoms. TMG binds to the human progesterone receptor with an affinity greater than medroxyprogesterone acetate (MPA), norethindrone (NET), and levonorgestrel (LNG). In contrast, TMG binds with low affinity to the androgen, glucocorticoid and mineralocorticoid receptor and has no measurable affinity for the estrogen receptor. Compared to other progestins, TMG demonstrates an improved separation of its PR affinity from its affinity to other classical steroid hormone receptors. In vivo, TMG has potent progestin activity. For example, TMG produces glandular differentiation of the uterine endometrium in rabbits and is about 30 and 60 times more potent than MPA and NET, respectively. In the rat, TMG maintains pregnancy, induces deciduoma formation, inhibits ovulation and has uterine anti-estrogenic activity. With respect to these endpoints, TMG appears to be more potent and selective on uterine epithelial responses than other classical progestin responses. In vivo, TMG does not have significant androgenic, glucocorticoid, anti-glucocorticoid or mineralocorticoid activity but does have anti-mineralocorticoid activity and modest anti-androgenic effects. This overall profile is qualitatively similar to progesterone. When TMG is administered chronically, it antagonizes the effect of estradiol on the uterus but does not antagonize the beneficial bone sparing activity of estradiol. In rat studies evaluating CNS GABAA receptor modulatory activity, TMG is less active on this likely undesirable endpoint than progesterone and norethindrone acetate, which may translate into fewer mood-related side effects. The results indicate that TMG is a potent and selective progestin with a preclinical profile well suited for hormone replacement therapy.

Pharmacological selectivity of the cloned human P2U-purinoceptor: potent activation by diadenosine tetraphosphate.

PubMed Central

Lazarowski, E. R.; Watt, W. C.; Stutts, M. J.; Boucher, R. C.; Harden, T. K.

1995-01-01

1. The human P2U-purinoceptor was stably expressed in 1321N1 human astrocytoma cells and the pharmacological selectivity of the expressed receptor was studied by measurement of inositol lipid hydrolysis. 2. High basal levels of inositol phosphates occurred in P2U-purinoceptor-expressing cells. This phenomenon was shown to be due to release of large amounts of ATP from 1321N1 cells, and could be circumvented by adoption of an assay protocol that did not involve medium changes. 3. UTP, ATP and ATP gamma S were full and potent agonists for activation of phospholipase C with EC50 values of 140 nM, 230 nM, and 1.72 microM, respectively. 5BrUTP, 2C1ATP and 8BrATP were also full agonists although less potent than their natural congeners. Little or no effect was observed with the selective P2Y-, P2X-, and P2T-purinoceptor agonists, 2MeSATP, alpha,beta-MeATP, and 2MeSADP, respectively. 4. Diadenosine tetraphosphate, Ap4A, was a surprisingly potent agonist at the expressed P2U-purinoceptor with an EC50 (720 nM) in the range of the most potent P2U-purinoceptor agonists. Ap4A may be a physiologically important activator of P2U-purinoceptors. PMID:8564228

4-aminoquinolone piperidine amides: noncovalent inhibitors of DprE1 with long residence time and potent antimycobacterial activity.

PubMed

Naik, Maruti; Humnabadkar, Vaishali; Tantry, Subramanyam J; Panda, Manoranjan; Narayan, Ashwini; Guptha, Supreeth; Panduga, Vijender; Manjrekar, Praveena; Jena, Lalit Kumar; Koushik, Krishna; Shanbhag, Gajanan; Jatheendranath, Sandesh; Manjunatha, M R; Gorai, Gopinath; Bathula, Chandramohan; Rudrapatna, Suresh; Achar, Vijayashree; Sharma, Sreevalli; Ambady, Anisha; Hegde, Naina; Mahadevaswamy, Jyothi; Kaur, Parvinder; Sambandamurthy, Vasan K; Awasthy, Disha; Narayan, Chandan; Ravishankar, Sudha; Madhavapeddi, Prashanti; Reddy, Jitendar; Prabhakar, Kr; Saralaya, Ramanatha; Chatterji, Monalisa; Whiteaker, James; McLaughlin, Bob; Chiarelli, Laurent R; Riccardi, Giovanna; Pasca, Maria Rosalia; Binda, Claudia; Neres, João; Dhar, Neeraj; Signorino-Gelo, François; McKinney, John D; Ramachandran, Vasanthi; Shandil, Radha; Tommasi, Ruben; Iyer, Pravin S; Narayanan, Shridhar; Hosagrahara, Vinayak; Kavanagh, Stefan; Dinesh, Neela; Ghorpade, Sandeep R

2014-06-26

4-Aminoquinolone piperidine amides (AQs) were identified as a novel scaffold starting from a whole cell screen, with potent cidality on Mycobacterium tuberculosis (Mtb). Evaluation of the minimum inhibitory concentrations, followed by whole genome sequencing of mutants raised against AQs, identified decaprenylphosphoryl-β-d-ribose 2'-epimerase (DprE1) as the primary target responsible for the antitubercular activity. Mass spectrometry and enzyme kinetic studies indicated that AQs are noncovalent, reversible inhibitors of DprE1 with slow on rates and long residence times of ∼100 min on the enzyme. In general, AQs have excellent leadlike properties and good in vitro secondary pharmacology profile. Although the scaffold started off as a single active compound with moderate potency from the whole cell screen, structure-activity relationship optimization of the scaffold led to compounds with potent DprE1 inhibition (IC50 < 10 nM) along with potent cellular activity (MIC = 60 nM) against Mtb.

Chemically triggered drug release from an antibody-drug conjugate leads to potent antitumour activity in mice.

PubMed

Rossin, Raffaella; Versteegen, Ron M; Wu, Jeremy; Khasanov, Alisher; Wessels, Hans J; Steenbergen, Erik J; Ten Hoeve, Wolter; Janssen, Henk M; van Onzen, Arthur H A M; Hudson, Peter J; Robillard, Marc S

2018-05-04

Current antibody-drug conjugates (ADCs) target internalising receptors on cancer cells leading to intracellular drug release. Typically, only a subset of patients with solid tumours has sufficient expression of such a receptor, while there are suitable non-internalising receptors and stroma targets. Here, we demonstrate potent therapy in murine tumour models using a non-internalising ADC that releases its drugs upon a click reaction with a chemical activator, which is administered in a second step. This was enabled by the development of a diabody-based ADC with a high tumour uptake and very low retention in healthy tissues, allowing systemic administration of the activator 2 days later, leading to efficient and selective activation throughout the tumour. In contrast, the analogous ADC comprising the protease-cleavable linker used in the FDA approved ADC Adcetris is not effective in these tumour models. This first-in-class ADC holds promise for a broader applicability of ADCs across patient populations.

A novel peptide with potent and broad-spectrum antiviral activities against multiple respiratory viruses

PubMed Central

Zhao, Hanjun; Zhou, Jie; Zhang, Ke; Chu, Hin; Liu, Dabin; Poon, Vincent Kwok-Man; Chan, Chris Chung-Sing; Leung, Ho-Chuen; Fai, Ng; Lin, Yong-Ping; Zhang, Anna Jin-Xia; Jin, Dong-Yan; Yuen, Kwok-Yung; Zheng, Bo-Jian

2016-01-01

A safe, potent and broad-spectrum antiviral is urgently needed to combat emerging respiratory viruses. In light of the broad antiviral activity of β-defensins, we tested the antiviral activity of 11 peptides derived from mouse β-defensin-4 and found that a short peptide, P9, exhibited potent and broad-spectrum antiviral effects against multiple respiratory viruses in vitro and in vivo, including influenza A virus H1N1, H3N2, H5N1, H7N7, H7N9, SARS-CoV and MERS-CoV. The antiviral activity of P9 was attributed to its high-affinity binding to viral glycoproteins, as well as the abundance of basic amino acids in its composition. After binding viral particles through viral surface glycoproteins, P9 entered into cells together with the viruses via endocytosis and prevented endosomal acidification, which blocked membrane fusion and subsequent viral RNA release. This study has paved the avenue for developing new prophylactic and therapeutic agents with broad-spectrum antiviral activities. PMID:26911565

Potent inhibition of VEGFR-2 activation by tight binding of green tea epigallocatechin gallate and apple procyanidins to VEGF: relevance to angiogenesis.

PubMed

Moyle, Christina W A; Cerezo, Ana B; Winterbone, Mark S; Hollands, Wendy J; Alexeev, Yuri; Needs, Paul W; Kroon, Paul A

2015-03-01

Excessive concentrations of vascular endothelial growth factor (VEGF) drive angiogenesis and cause complications such as increased growth of tumours and atherosclerotic plaques. The aim of this study was to determine the molecular mechanism underlying the potent inhibition of VEGF signalling by polyphenols. We show that the polyphenols epigallocatechin gallate from green tea and procyanidin oligomers from apples potently inhibit VEGF-induced VEGF receptor-2 (VEGFR-2) signalling in human umbilical vein endothelial cells by directly interacting with VEGF. The polyphenol-induced inhibition of VEGF-induced VEGFR-2 activation occurred at nanomolar polyphenol concentrations and followed bi-phasic inhibition kinetics. VEGF activity could not be recovered by dialysing VEGF-polyphenol complexes. Exposure of VEGF to epigallocatechin gallate or procyanidin oligomers strongly inhibited subsequent binding of VEGF to human umbilical vein endothelial cells expressing VEGFR-2. Remarkably, even though VEGFR-2 signalling was completely inhibited at 1 μM concentrations of polyphenols, endothelial nitric oxide synthase was shown to still be activated via the PI3K/Akt signalling pathway which is downstream of VEGFR-2. These data demonstrate for the first time that VEGF is a key molecular target for specific polyphenols found in tea, apples and cocoa which potently inhibit VEGF signalling and angiogenesis at physiological concentrations. These data provide a plausible mechanism which links bioactive compounds in food with their beneficial effects. © 2014 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Imidazopyridine-5,6,7,8-tetrahydro-8-quinolinamine derivatives with potent activity against HIV-1.

PubMed

Gudmundsson, Kristjan S; Boggs, Sharon D; Catalano, John G; Svolto, Angilique; Spaltenstein, Andrew; Thomson, Michael; Wheelan, Pat; Jenkinson, Stephen

2009-11-15

Synthesis of several novel imidazopyridine-5,6,7,8-tetrahydro-8-quinolinamine derivatives with potent activity against HIV are described. Synthetic approaches allowing for variation of the substitution pattern are outlined and resulting changes in antiviral activity and pharmacokinetics are highlighted. Several compounds with low nanomolar anti-HIV activity and oral bioavailability are described.

Novel 5-aryl-1,3-dihydro-indole-2-thiones. potent, orally active progesterone receptor agonists.

PubMed

Fensome, Andrew; Koko, Marci; Wrobel, Jay; Zhang, Puwen; Zhang, Zhiming; Cohen, Jeffrey; Lundeen, Scott; Rudnick, Kelly; Zhu, Yuan; Winneker, Richard

2003-04-07

During the course of our studies on 3,3-disubstituted-5-aryloxindoles derived progesterone receptor (PR) antagonists we discovered that changing the amide funtionality to a thio-amide resulted in compounds displaying potent PR agonist activity. In this communication, the synthesis, structure activity relationships (SAR) and in vivo activity of various 5-arylthio-oxindoles will be discussed.

Kisameet Clay Exhibits Potent Antibacterial Activity against the ESKAPE Pathogens

PubMed Central

Behroozian, Shekooh; Svensson, Sarah L.

2016-01-01

ABSTRACT The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens cause an increasing number of nosocomial infections worldwide since they escape the inhibitory effect of the available antibiotics and the immune response. Here, we report the broad-spectrum and potent antibacterial activity of Kisameet clay, a natural clay mineral from British Columbia, Canada, against a group of multidrug-resistant ESKAPE strains. The results suggest that this natural clay might be developed as a therapeutic option for the treatment of serious infections caused by these important pathogens. PMID:26814180

Antifreeze Protein Mimetic Metallohelices with Potent Ice Recrystallization Inhibition Activity.

PubMed

Mitchell, Daniel E; Clarkson, Guy; Fox, David J; Vipond, Rebecca A; Scott, Peter; Gibson, Matthew I

2017-07-26

Antifreeze proteins are produced by extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure-property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition.

Tear gasses CN, CR, and CS are potent activators of the human TRPA1 receptor

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

Brone, Bert; Peeters, Pieter J.; Marrannes, Roger

2008-09-01

The TRPA1 channel is activated by a number of pungent chemicals, such as allylisothiocyanate, present in mustard oil and thiosulfinates present in garlic. Most of the known activating compounds contain reactive, electrophilic chemical groups, reacting with cysteine residues in the active site of the TRPA1 channel. This covalent modification results in activation of the channel and has been shown to be reversible for several ligands. Commonly used tear gasses CN, CR and CS are also pungent chemicals, and in this study we show that they are extremely potent and selective activators of the human TRPA1 receptor. To our knowledge, thesemore » are the most potent TRPA1 agonists known to date. The identification of the molecular target for these tear gasses may open up possibilities to alleviate the effects of tear gasses via treatment with TRPA1 antagonists. In addition these results may contribute to the basic knowledge of the TRPA1 channel that is gaining importance as a pharmacological target.« less

Potent apoptosis-inducing activity of erypoegin K, an isoflavone isolated from Erythrina poeppigiana, against human leukemia HL-60 cells.

PubMed

Hikita, Kiyomi; Hattori, Natsuki; Takeda, Aya; Yamakage, Yuko; Shibata, Rina; Yamada, Saori; Kato, Kuniki; Murata, Tomiyasu; Tanaka, Hitoshi; Kaneda, Norio

2018-01-01

Erypoegin K is an isoflavone isolated from the stem bark of Erythrina poeppigiana. It contains a furan group at the A-ring of the core isoflavone structure and can inhibit the activity of glyoxalase I, an enzyme that catalyzes the detoxification of methylglyoxal (MG), a by-product of glycolysis. In the present study, we found that erypoegin K has a potent cytotoxic effect on human leukemia HL-60 cells. Its cytotoxic effect was much stronger than that of a known glyoxalase I inhibitor S-p-bromobenzylglutathione cyclopentyl diester. Conversely, erypoegin K demonstrated weak cytotoxicity toward normal human peripheral lymphocytes. The treatment of HL-60 cells with erypoegin K significantly induced caspase-3 activity, whereas the pretreatment of the cells with caspase-3 inhibitor suppressed erypoegin K-induced cell death. Furthermore, nuclear condensation and apoptotic genome DNA fragmentation were observed in erypoegin K-treated HL-60 cells. These results indicated that the observed cell death was mediated by apoptosis. In addition, the toxic compound MG was highly accumulated in the culture medium of erypoegin K-treated HL-60 cells, suggesting that cell apoptosis was triggered by extracellular MG. The present study showed that erypoegin K has a potent apoptosis-inducing effect on cancerous cell lines, such as HL-60.

Synthesis of novel di- and tricationic carbapenems with potent anti-MRSA activity.

PubMed

Maruyama, Takahisa; Yamamoto, Yasuo; Kano, Yuko; Kurazono, Mizuyo; Shitara, Eiki; Iwamatsu, Katsuyoshi; Atsumi, Kunio

2009-01-15

A new series of 1beta-methyl carbapenems possessing a 6,7-disubstituted imidazo[5,1-b]thiazol-2-yl group directly attached to the C-2 position of the carbapenem nucleus was prepared, and their activities against methicillin-resistant Staphylococcus aureus (MRSA) were evaluated. First, a benzyl moiety was introduced at the C-6 position of imidazo[5,1-b]thiazole attached to the carbapenem. These benzylated molecules showed potent anti-MRSA activity, but poor water solubility. In order to overcome this drawback, we designed and synthesized di- and tricationic carbapenems and finally discovered a novel carbapenem (15i), which exhibited excellent anti-MRSA activity and good water solubility.

Discovery of potent, selective, orally active benzoxazepine-based Orexin-2 receptor antagonists.

PubMed

Fujimoto, Tatsuhiko; Kunitomo, Jun; Tomata, Yoshihide; Nishiyama, Keiji; Nakashima, Masato; Hirozane, Mariko; Yoshikubo, Shin-Ichi; Hirai, Keisuke; Marui, Shogo

2011-11-01

During our efforts to identify a series of potent, selective, orally active human Orexin-2 Receptor (OX2R) antagonists, we elucidated structure-activity relationship (SAR) on the 7-position of a benzoxazepine scaffold by utilizing Hammett σ(p) and Hansch-Fujita π value as aromatic substituent constants. The attempts led to the discovery of compound 1m, possessing good in vitro potency with over 100-fold selectivity against OX1R, good metabolic stability in human and rat liver microsome, good oral bioavailability in rats, and in vivo antagonistic activity in rats by oral administration. Copyright © 2011 Elsevier Ltd. All rights reserved.

Structure-Based Design of Potent and Selective 3-Phosphoinositide-Dependent Kinase-1 (PDK1) Inhibitors

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

Medina, Jesus R.; Becker, Christopher J.; Blackledge, Charles W.

2014-10-02

Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction ofmore » phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.« less

In Vitro Antibacterial Activity of AZD0914, a New Spiropyrimidinetrione DNA Gyrase/Topoisomerase Inhibitor with Potent Activity against Gram-Positive, Fastidious Gram-Negative, and Atypical Bacteria

PubMed Central

Bradford, Patricia A.; Otterson, Linda G.; Basarab, Gregory S.; Kutschke, Amy C.; Giacobbe, Robert A.; Patey, Sara A.; Alm, Richard A.; Johnstone, Michele R.; Potter, Marie E.; Miller, Paul F.; Mueller, John P.

2014-01-01

AZD0914 is a new spiropyrimidinetrione bacterial DNA gyrase/topoisomerase inhibitor with potent in vitro antibacterial activity against key Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus pyogenes, and Streptococcus agalactiae), fastidious Gram-negative (Haemophilus influenzae and Neisseria gonorrhoeae), atypical (Legionella pneumophila), and anaerobic (Clostridium difficile) bacterial species, including isolates with known resistance to fluoroquinolones. AZD0914 works via inhibition of DNA biosynthesis and accumulation of double-strand cleavages; this mechanism of inhibition differs from those of other marketed antibacterial compounds. AZD0914 stabilizes and arrests the cleaved covalent complex of gyrase with double-strand broken DNA under permissive conditions and thus blocks religation of the double-strand cleaved DNA to form fused circular DNA. Whereas this mechanism is similar to that seen with fluoroquinolones, it is mechanistically distinct. AZD0914 exhibited low frequencies of spontaneous resistance in S. aureus, and if mutants were obtained, the mutations mapped to gyrB. Additionally, no cross-resistance was observed for AZD0914 against recent bacterial clinical isolates demonstrating resistance to fluoroquinolones or other drug classes, including macrolides, β-lactams, glycopeptides, and oxazolidinones. AZD0914 was bactericidal in both minimum bactericidal concentration and in vitro time-kill studies. In in vitro checkerboard/synergy testing with 17 comparator antibacterials, only additivity/indifference was observed. The potent in vitro antibacterial activity (including activity against fluoroquinolone-resistant isolates), low frequency of resistance, lack of cross-resistance, and bactericidal activity of AZD0914 support its continued development. PMID:25385112

Kisameet Clay Exhibits Potent Antibacterial Activity against the ESKAPE Pathogens.

PubMed

Behroozian, Shekooh; Svensson, Sarah L; Davies, Julian

2016-01-26

The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens cause an increasing number of nosocomial infections worldwide since they escape the inhibitory effect of the available antibiotics and the immune response. Here, we report the broad-spectrum and potent antibacterial activity of Kisameet clay, a natural clay mineral from British Columbia, Canada, against a group of multidrug-resistant ESKAPE strains. The results suggest that this natural clay might be developed as a therapeutic option for the treatment of serious infections caused by these important pathogens. More than 50 years of misuse and overuse of antibiotics has led to a plague of antibiotic resistance that threatens to reduce the efficacy of antimicrobial agents available for the treatment of infections due to resistant organisms. The main threat is nosocomial infections in which certain pathogens, notably the ESKAPE organisms, are essentially untreatable and contribute to increasing mortality and morbidity in surgical wards. The pipeline of novel antimicrobials in the pharmaceutical industry is essentially empty. Thus, there is a great need to seek for new sources for the treatment of recalcitrant infectious diseases. We describe experiments that demonstrate the efficacy of a "natural" medicine, Kisameet clay, against all of the ESKAPE strains. We suggest that this material is worthy of clinical investigation for the treatment of infections due to multidrug-resistant organisms. Copyright © 2016 Behroozian et al.

A new peptide (Ruviprase) purified from the venom of Daboia russelii russelii shows potent anticoagulant activity via non-enzymatic inhibition of thrombin and factor Xa.

PubMed

Thakur, Rupamoni; Kumar, Ashok; Bose, Biplab; Panda, Dulal; Saikia, Debashree; Chattopadhyay, Pronobesh; Mukherjee, Ashis K

2014-10-01

Compounds showing dual inhibition of thrombin and factor Xa (FXa) are the subject of great interest owing to their broader specificity for effective anticoagulation therapy against cardiovascular disorders. This is the first report on the functional characterization and assessment of therapeutic potential of a 4423.6 Da inhibitory peptide (Ruviprase) purified from Daboia russelii russelii venom. The secondary structure of Ruviprase is composed of α-helices (61.9%) and random coils (38.1%). The partial N-terminal sequence (E(1)-V(2)-X(3)-W(4)-W(5)-W(6)-A(7)-Q(8)-L(9)-S(10)) of Ruviprase demonstrated significant similarity (80.0%) with an internal sequence of apoptosis-stimulating protein reported from the venom of Ophiophagus hannah and Python bivittatus; albeit Ruviprase did not show sequence similarity with existing thrombin/FXa inhibitors, suggesting its uniqueness. Ruviprase demonstrated a potent in vitro anticoagulant property and inhibited both thrombin and FXa following slow binding kinetics. Ruviprase inhibited thrombin by binding to its active site via an uncompetitive mechanism with a Ki value and dissociation constant (KD) of 0.42 μM and 0.46 μM, respectively. Conversely, Ruviprase demonstrated mixed inhibition (Ki = 0.16 μM) of FXa towards its physiological substrate prothrombin. Furthermore, the biological properties of Ruviprase could not be neutralized by commercial polyvalent or monovalent antivenom. Ruviprase at a dose of 2.0 mg/kg was non-toxic and showed potent in vivo anticoagulant activity after 6 h of intraperitoneal treatment in mice. Because of the potent anticoagulant property as well as non-toxic nature of Ruviprase, the possible application of the peptide as an antithrombotic agent for combating thrombosis-associated ailments appears promising. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Vaginal concentrations of lactic acid potently inactivate HIV

PubMed Central

Aldunate, Muriel; Tyssen, David; Johnson, Adam; Zakir, Tasnim; Sonza, Secondo; Moench, Thomas; Cone, Richard; Tachedjian, Gilda

2013-01-01

Objectives When Lactobacillus spp. dominate the vaginal microbiota of women of reproductive age they acidify the vagina to pH <4.0 by producing ∼1% lactic acid in a nearly racemic mixture of d- and l-isomers. We determined the HIV virucidal activity of racemic lactic acid, and its d- and l-isomers, compared with acetic acid and acidity alone (by the addition of HCl). Methods HIV-1 and HIV-2 were transiently treated with acids in the absence or presence of human genital secretions at 37°C for different time intervals, then immediately neutralized and residual infectivity determined in the TZM-bl reporter cell line. Results l-lactic acid at 0.3% (w/w) was 17-fold more potent than d-lactic acid in inactivating HIVBa-L. Complete inactivation of different HIV-1 subtypes and HIV-2 was achieved with ≥0.4% (w/w) l-lactic acid. At a typical vaginal pH of 3.8, l-lactic acid at 1% (w/w) more potently and rapidly inactivated HIVBa-L and HIV-1 transmitter/founder strains compared with 1% (w/w) acetic acid and with acidity alone, all adjusted to pH 3.8. A final concentration of 1% (w/w) l-lactic acid maximally inactivated HIVBa-L in the presence of cervicovaginal secretions and seminal plasma. The anti-HIV activity of l-lactic acid was pH dependent, being abrogated at neutral pH, indicating that its virucidal activity is mediated by protonated lactic acid and not the lactate anion. Conclusions l-lactic acid at physiological concentrations demonstrates potent HIV virucidal activity distinct from acidity alone and greater than acetic acid, suggesting a protective role in the sexual transmission of HIV. PMID:23657804

Direct Regulation of Androgen Receptor Activity by Potent CYP17 Inhibitors in Prostate Cancer Cells*

PubMed Central

Soifer, Harris S.; Souleimanian, Naira; Wu, Sijian; Voskresenskiy, Anatoliy M.; Kisaayak Collak, Filiz; Cinar, Bekir; Stein, Cy A.

2012-01-01

TOK-001 and abiraterone are potent 17-heteroarylsteroid (17-HAS) inhibitors of Cyp17, one of the rate-limiting enzymes in the biosynthesis of testosterone from cholesterol in prostate cancer cells. Nevertheless, the molecular mechanism underlying the prevention of prostate cell growth by 17-HASs still remains elusive. Here, we assess the effects of 17-HASs on androgen receptor (AR) activity in LNCaP and LAPC-4 cells. We demonstrate that both TOK-001 and abiraterone reduced AR protein and mRNA expression, and antagonized AR-dependent promoter activation induced by androgen. TOK-001, but not abiraterone, is an effective apparent competitor of the radioligand [3H]R1881 for binding to the wild type and various mutant AR (W741C, W741L) proteins. In agreement with these data, TOK-001 is a consistently superior inhibitor than abiraterone of R1881-induced transcriptional activity of both wild type and mutant AR. However, neither agent was able to trans-activate the AR in the absence of R1881. Our data demonstrate that phospho-4EBP1 levels are significantly reduced by TOK-001 and to a lesser extent by abiraterone alcohol, and suggest a mechanism by which cap-dependent translation is suppressed by blocking assembly of the eIF4F and eIF4G complex to the mRNA 5′ cap. Thus, the effects of these 17-HASs on AR signaling are complex, ranging from a decrease in testosterone production through the inhibition of Cyp17 as previously described, to directly reducing both AR protein expression and R1881-induced AR trans-activation. PMID:22174412

Discovery of novel histidine-derived lipo-amino acids: applied in the synthesis of ultra-short antimicrobial peptidomimetics having potent antimicrobial activity, salt resistance and protease stability.

PubMed

Ahn, Mija; Murugan, Ravichandran N; Jacob, Binu; Hyun, Jae-Kyung; Cheong, Chaejoon; Hwang, Eunha; Park, Hyo-Nam; Seo, Ji-Hyung; Srinivasrao, G; Lee, Kyung S; Shin, Song Yub; Bang, Jeong Kyu

2013-10-01

Here we report for the first time the synthesis of Histidine (His) derived lipo-amino acids having pendant lipid tails at N(τ)- and N(π)-positions on imidazole group of His and applied it into synthesis of lipo-peptides. The attachment of His-derived lipo-amino acid into the very short inactive cationic peptides endows potent antimicrobial activity against Gram-positive and Gram-negative bacteria without hemolytic activity. Furthermore, our designed His-derived lipo-peptidomimetics (HDLPs) consisting of two or three residues displayed strong anti-MRSA activity and protease stability as well as retained potent antimicrobial activity under high salt concentration. Our results demonstrate that the novel lipo-amino acid is highly flexible to synthesize and carry out the extensive structure-activity relationship (SAR) on lipo-antimicrobial peptidomimetics and represents a unique amenable platform for modifying parameters important for antimicrobial activity. Through this study, we proved that the discovery of His-derived lipo-amino acid and the corresponding HDLPs are an excellent candidate as a lead compound for the development of novel antimicrobial agents. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Identification of a novel inhibitor of isocitrate lyase as a potent antitubercular agent against both active and non-replicating Mycobacterium tuberculosis.

PubMed

Liu, Yishuang; Zhou, Shuang; Deng, Qi; Li, Xinghua; Meng, Jianzhou; Guan, Yan; Li, Chuanyou; Xiao, Chunling

2016-03-01

Screen and identify novel inhibitors of isocitrate lyase (ICL) as potent antitubercular agents against Mycobacterium tuberculosis and determine their inhibitory characteristics, antitubercular activities and mechanisms of action. Recombinant ICL of M. tuberculosis was expressed and purified, which was used for high-throughput screening (HTS) and the following experiments. A total of 71,765 compounds were screened to identify ICL inhibitors which were then evaluated for their roles as potent antitubercular agents. To determine the inhibitory characteristics of the agents against latent M. tuberculosis in persistent infections, a macrophage model (mouse J774A.1 cell) infected with Mycobacterium marinum BAA-535 strain was built and assessed. The potent antitubercular agents were identified using the macrophage model. Then, the inhibitory intensity and mode of the agents that exhibit on ICL protein of M. tuberculosis were analyzed, and the interaction mechanisms were preliminarily clarified according to the parameters of enzyme kinetics, circular dichroism experiments, fluorescence quenching assay, and molecular docking. The previously established ICL inhibitor screening model was evaluated to be suitable for HTS assay. Of the 71,765 compounds, 13 of them were identified to inhibit ICL effectively and stably. IMBI-3 demonstrated the most significant inhibitory activity with IC50 of 30.9 μmol/L. Its minimum inhibitory concentration (MIC) for M. tuberculosis, including extensively drug-resistant tuberculosis (XDR-TB) and multidrug-resistant tuberculosis (MDR-TB), were determined in the range of 0.25-1 μg/mL. When IMBI-3 is used in combination with isoniazid, the colony-forming units (CFU) counting of latent M. tuberculosis in J774A.1 macrophage cells decreased significantly as IMBI-3 concentration increased. The inhibition mode of IMBI-3 on ICL was probably competitive inhibition with an inhibition constant (Ki) of approximate 1.85 μmol/L. The interaction between IMBI

CEP-26401 (irdabisant), a potent and selective histamine H₃ receptor antagonist/inverse agonist with cognition-enhancing and wake-promoting activities.

PubMed

Raddatz, Rita; Hudkins, Robert L; Mathiasen, Joanne R; Gruner, John A; Flood, Dorothy G; Aimone, Lisa D; Le, Siyuan; Schaffhauser, Hervé; Duzic, Emir; Gasior, Maciej; Bozyczko-Coyne, Donna; Marino, Michael J; Ator, Mark A; Bacon, Edward R; Mallamo, John P; Williams, Michael

2012-01-01

CEP-26401 [irdabisant; 6-{4-[3-((R)-2-methyl-pyrrolidin-1-yl)-propoxy]-phenyl}-2H-pyridazin-3-one HCl] is a novel, potent histamine H₃ receptor (H₃R) antagonist/inverse agonist with drug-like properties. High affinity of CEP-26401 for H₃R was demonstrated in radioligand binding displacement assays in rat brain membranes (K(i) = 2.7 ± 0.3 nM) and recombinant rat and human H₃R-expressing systems (K(i) = 7.2 ± 0.4 and 2.0 ± 1.0 nM, respectively). CEP-26401 displayed potent antagonist and inverse agonist activities in [³⁵S]guanosine 5'-O-(γ-thio)triphosphate binding assays. After oral dosing of CEP-26401, occupancy of H₃R was estimated by the inhibition of ex vivo binding in rat cortical slices (OCC₅₀ = 0.1 ± 0.003 mg/kg), and antagonism of the H₃R agonist R-α-methylhistamine- induced drinking response in the rat dipsogenia model was demonstrated in a similar dose range (ED₅₀ = 0.06 mg/kg). CEP-26401 improved performance in the rat social recognition model of short-term memory at doses of 0.01 to 0.1 mg/kg p.o. and was wake-promoting at 3 to 30 mg/kg p.o. In DBA/2NCrl mice, CEP-26401 at 10 and 30 mg/kg i.p. increased prepulse inhibition (PPI), whereas the antipsychotic risperidone was effective at 0.3 and 1 mg/kg i.p. Coadministration of CEP-26401 and risperidone at subefficacious doses (3 and 0.1 mg/kg i.p., respectively) increased PPI. These results demonstrate potent behavioral effects of CEP-26401 in rodent models and suggest that this novel H₃R antagonist may have therapeutic utility in the treatment of cognitive and attentional disorders. CEP-26401 may also have therapeutic utility in treating schizophrenia or as adjunctive therapy to approved antipsychotics.

Structurally well-defined macrophage activating factor derived from vitamin D3-binding protein has a potent adjuvant activity for immunization.

PubMed

Yamamoto, N; Naraparaju, V R

1998-06-01

Freund's adjuvant produced severe inflammation that augments development of antibodies. Thus, mixed administration of antigens with adjuvant was not required as long as inflammation was induced in the hosts. Since macrophage activation for phagocytosis and antigen processing is the first step of antibody development, inflammation-primed macrophage activation plays a major role in immune development. Therefore, macrophage activating factor should act as an adjuvant for immunization. The inflammation-primed macrophage activation process is the major macrophage activating cascade that requires participation of serum vitamin D3-binding protein (DBP; human DBP is known as Gc protein) and glycosidases of B and T lymphocytes. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase efficiently generated the most potent macrophage activating factor (designated GcMAF) we have ever encountered. Administration of GcMAF (20 or 100 pg/mouse) resulted in stimulation of the progenitor cells for extensive mitogenesis and activation of macrophages. Administration of GcMAF (100 pg/mouse) along with immunization of mice with sheep red blood cells (SRBC) produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days. Thus, GcMAF has a potent adjuvant activity for immunization. Although malignant tumours are poorly immunogenic, 4 days after GcMAF-primed immunization of mice with heat-killed Ehrlich ascites tumour cells, the ascites tumour was no longer transplantable in these mice.

Novel triterpenoids isolated from raisins exert potent antiproliferative activities by targeting mitochondrial and Ras/Raf/ERK signaling in human breast cancer cells.

PubMed

Liu, Juan; Wang, Yihai; Liu, Rui Hai; He, Xiangjiu

2016-07-13

Raisins are produced in many regions of the world and may be eaten raw or used in cooking, baking and brewing. Bioactivity-guided fractionation of raisins was used to determine the chemical identity of bioactive constituents. Seven triterpenoids, including three novel triterpenoids, were isolated and identified. The novel triterpenoids were elucidated to be 3β,13β-dihydroxy-12,13-dihydrooleanolic acid (1), 3β,12β,13β-trihydroxy-12,13-dihydrooleanolic acid (2, TOA), and 3β,13β-dihydroxy-12,13-dihydroursolic acid (7), respectively. TOA showed the highest antiproliferative activity against MCF-7/DOX cells, with an EC50 value of 3.60 ± 0.55 μM. Compounds 1, 3 and 7 also exhibited potent antiproliferative activity against MCF-7/DOX cells, with an EC50 value of 7.10 ± 0.65, 10.22 ± 0.90 and 8.91 ± 1.12 μM. Compounds 1 and 2 also exhibited potent antioxidant activities. Moreover, the detailed cytotoxic mechanisms of TOA were investigated by targeting the mitochondrial and protein tyrosine kinase signaling (Ras/Raf/ERK). The results strongly demonstrated that the novel triterpenoids isolated from raisins could be promising candidates for therapy of breast cancer.

Consecutive pharmacological activation of PKA and PKC mimics the potent cardioprotection of temperature preconditioning

PubMed Central

Khaliulin, Igor; Parker, Joanna E.; Halestrap, Andrew P.

2010-01-01

Aims Temperature preconditioning (TP) provides very powerful protection against ischaemia/reperfusion. Understanding the signalling pathways involved may enable the development of effective pharmacological cardioprotection. We investigated the interrelationship between activation of protein kinase A (PKA) and protein kinase C (PKC) in the signalling mechanisms of TP and developed a potent pharmacological intervention based on this mechanism. Methods and results Isolated rat hearts were subjected to TP, 30 min global ischaemia, and 60 min reperfusion. Other control and TP hearts were perfused with either sotalol (β-adrenergic blocker) or H-89 (PKA inhibitor). Some hearts were pre-treated with either isoproterenol (β-adrenergic agonist) or adenosine (PKC activator) that were given alone, simultaneously, or sequentially. Pre-treatment with isoproterenol, adenosine, and the consecutive isoproterenol/adenosine treatment was also combined with the PKC inhibitor chelerythrine. Cardioprotection was evaluated by haemodynamic function recovery, lactate dehydrogenase release, measurement of mitochondrial permeability transition pore opening, and protein carbonylation during reperfusion. Cyclic AMP and PKA activity were increased in TP hearts. H-89 and sotalol blocked the cardioprotective effect of TP and TP-induced PKC activation. Isoproterenol, adenosine, and the consecutive treatment increased PKC activity during pre-ischaemia. Isoproterenol significantly reduced myocardial glycogen content. Isoproterenol and adenosine, alone or simultaneously, protected hearts but the consecutive treatment gave the highest protection. Cardioprotective effects of adenosine were completely blocked by chelerythrine but those of the consecutive treatment only attenuated. Conclusion The signal transduction pathway of TP involves PKA activation that precedes PKC activation. Pharmacologically induced consecutive PKA/PKC activation mimics TP and induces extremely potent cardioprotection. PMID

Optimization of 2-Anilino 4-Amino Substituted Quinazolines into Potent Antimalarial Agents with Oral in Vivo Activity.

PubMed

Gilson, Paul R; Tan, Cyrus; Jarman, Kate E; Lowes, Kym N; Curtis, Joan M; Nguyen, William; Di Rago, Adrian E; Bullen, Hayley E; Prinz, Boris; Duffy, Sandra; Baell, Jonathan B; Hutton, Craig A; Jousset Subroux, Helene; Crabb, Brendan S; Avery, Vicky M; Cowman, Alan F; Sleebs, Brad E

2017-02-09

Novel antimalarial therapeutics that target multiple stages of the parasite lifecycle are urgently required to tackle the emerging problem of resistance with current drugs. Here, we describe the optimization of the 2-anilino quinazoline class as antimalarial agents. The class, identified from publicly available antimalarial screening data, was optimized to generate lead compounds that possess potent antimalarial activity against P. falciparum parasites comparable to the known antimalarials, chloroquine and mefloquine. During the optimization process, we defined the functionality necessary for activity and improved in vitro metabolism and solubility. The resultant lead compounds possess potent activity against a multidrug resistant strain of P. falciparum and arrest parasites at the ring phase of the asexual stage and also gametocytogensis. Finally, we show that the lead compounds are orally efficacious in a 4 day murine model of malaria disease burden.

6,7-Dimorpholinoalkoxy quinazoline derivatives as potent EGFR inhibitors with enhanced antiproliferative activities against tumor cells.

PubMed

Zhang, Yaling; Chen, Li; Xu, Hongjiang; Li, Xiabing; Zhao, Lijun; Wang, Wei; Li, Baolin; Zhang, Xiquan

2018-03-10

A series of novel 6,7-dimorpholinoalkoxy quinazoline derivatives was designed, synthesized and evaluated as potent EGFR inhibitors. Most of synthesized derivatives exhibited moderate to excellent antiproliferative activities against five human tumor cell lines. Compound 8d displayed the most remarkable inhibitory activities against tumor cells expressing wild type (A431, A549 and SW480 cells) or mutant (HCC827 and NCI-H1975 cells) epidermal growth factor receptor (EGFR) (with IC 50 values in the range of 0.37-4.87 μM), as well as more potent inhibitory effects against recombinant EGFR tyrosine kinase (EGFR-TK, wt or T790M) (with the IC 50 values of 7.0 and 9.3 nM, respectively). Molecular docking showed that 8d can form four hydrogen bonds with EGFR, and two of them were located in the Asp855-Phe856-Gly857 (DFG) motif of EGFR. Meanwhile, 8d can significantly block EGF-induced EGFR activation and the phosphorylation of its downstream proteins such as Akt and Erk1/2 in human NSCLC cells. Also, 8d mediated cell apoptosis and the prolongation of cell cycle progression in G0/G1-phase in A549 cells. The work would have remarkable implications for further design and development of more potent EGFR tyrosine kinase inhibitors (TKIs). Copyright © 2018 Elsevier Masson SAS. All rights reserved.

New fluoroprostaglandin F(2alpha) derivatives with prostanoid FP-receptor agonistic activity as potent ocular-hypotensive agents.

PubMed

Nakajima, Tadashi; Matsugi, Takeshi; Goto, Wakana; Kageyama, Masaaki; Mori, Nobuaki; Matsumura, Yasushi; Hara, Hideaki

2003-12-01

To find new prostanoid FP-receptor agonists possessing potent ocular-hypotensive effects with minimal side effects, we evaluated the agonistic activities of newly synthesized prostaglandin F(2alpha) derivatives for the prostanoid FP-receptor both in vitro and in vivo. The iris constrictions induced by the derivatives and their effects on melanin content were examined using cat isolated iris sphincters and cultured B16 melanoma cells, respectively. The effects of derivative ester forms on miosis and intraocular pressure (IOP) were evaluated in cats and cynomolgus monkeys, respectively. Of these derivatives, 6 out of 12 compounds were more potent iris constrictors, with EC(50) values of 0.6 to 9.4 nM, than a carboxylic acid of latanoprost (EC(50)=13.6 nM). A carboxylic acid of latanoprost (100 microM) significantly increased the melanin content of cultured B16 melanoma cells, but some 15,15-difluoro derivatives, such as AFP-157 and AFP-172, did not. Topically applied AFP-168, AFP-169 and AFP-175 (isopropyl ester, methyl ester and ethyl ester forms, respectively, of AFP-172) induced miosis in cats more potently than latanoprost. AFP-168 (0.0005%) reduced IOP to the same extent as 0.005% latanoprost (for at least 8 h). These findings indicate that 15,15-difluoroprostaglandin F(2alpha) derivatives, especially AFP-168, have more potent prostanoid FP-receptor agonistic activities than latanoprost. Hence, AFP-168 may be worthy of further evaluation as an ocular-hypotensive agent.

A combined pharmacodynamic quantitative and qualitative model reveals the potent activity of daptomycin and delafloxacin against Staphylococcus aureus biofilms.

PubMed

Bauer, Julia; Siala, Wafi; Tulkens, Paul M; Van Bambeke, Françoise

2013-06-01

Biofilms are associated with persistence of Staphylococcus aureus infections and therapeutic failures. Our aim was to set up a pharmacodynamic model comparing antibiotic activities against biofilms and examining in parallel their effects on viability and biofilm mass. Biofilms of S. aureus ATCC 25923 (methicillin-sensitive S. aureus [MSSA]) or ATCC 33591 (methicillin-resistant S. aureus [MRSA]) were obtained by culture in 96-well plates for 6 h/24 h. Antibiotic activities were assessed after 24/48 h of exposure to concentrations ranging from 0.5 to 512 times the MIC. Biofilm mass and bacterial viability were quantified using crystal violet and the redox indicator resazurin. Biofilms stained with Live/Dead probes were observed by using confocal microscopy. Concentration-effect curves fitted sigmoidal regressions, with a 50% reduction toward both matrix and viability obtained at sub-MIC or low multiples of MICs against young biofilms for all antibiotics tested. Against mature biofilms, maximal efficacies and potencies were reduced, with none of the antibiotics being able to completely destroy the matrix. Delafloxacin and daptomycin were the most potent, reducing viability by more than 50% at clinically achievable concentrations against both strains, as well as reducing biofilm depth, as observed in confocal microscopy. Rifampin, tigecycline, and moxifloxacin were effective against mature MRSA biofilms, while oxacillin demonstrated activity against MSSA. Fusidic acid, vancomycin, and linezolid were less potent overall. Antibiotic activity depends on biofilm maturity and bacterial strain. The pharmacodynamic model developed allows ranking of antibiotics with respect to efficacy and potency at clinically achievable concentrations and highlights the potential utility of daptomycin and delafloxacin for the treatment of biofilm-related infections.

A Combined Pharmacodynamic Quantitative and Qualitative Model Reveals the Potent Activity of Daptomycin and Delafloxacin against Staphylococcus aureus Biofilms

PubMed Central

Bauer, Julia; Siala, Wafi; Tulkens, Paul M.

2013-01-01

Biofilms are associated with persistence of Staphylococcus aureus infections and therapeutic failures. Our aim was to set up a pharmacodynamic model comparing antibiotic activities against biofilms and examining in parallel their effects on viability and biofilm mass. Biofilms of S. aureus ATCC 25923 (methicillin-sensitive S. aureus [MSSA]) or ATCC 33591 (methicillin-resistant S. aureus [MRSA]) were obtained by culture in 96-well plates for 6 h/24 h. Antibiotic activities were assessed after 24/48 h of exposure to concentrations ranging from 0.5 to 512 times the MIC. Biofilm mass and bacterial viability were quantified using crystal violet and the redox indicator resazurin. Biofilms stained with Live/Dead probes were observed by using confocal microscopy. Concentration-effect curves fitted sigmoidal regressions, with a 50% reduction toward both matrix and viability obtained at sub-MIC or low multiples of MICs against young biofilms for all antibiotics tested. Against mature biofilms, maximal efficacies and potencies were reduced, with none of the antibiotics being able to completely destroy the matrix. Delafloxacin and daptomycin were the most potent, reducing viability by more than 50% at clinically achievable concentrations against both strains, as well as reducing biofilm depth, as observed in confocal microscopy. Rifampin, tigecycline, and moxifloxacin were effective against mature MRSA biofilms, while oxacillin demonstrated activity against MSSA. Fusidic acid, vancomycin, and linezolid were less potent overall. Antibiotic activity depends on biofilm maturity and bacterial strain. The pharmacodynamic model developed allows ranking of antibiotics with respect to efficacy and potency at clinically achievable concentrations and highlights the potential utility of daptomycin and delafloxacin for the treatment of biofilm-related infections. PMID:23571532

3,4-Dihydro-2H-benzoxazinones are 5-HT(1A) receptor antagonists with potent 5-HT reuptake inhibitory activity.

PubMed

Atkinson, Peter J; Bromidge, Steven M; Duxon, Mark S; Gaster, Laramie M; Hadley, Michael S; Hammond, Beverley; Johnson, Christopher N; Middlemiss, Derek N; North, Stephanie E; Price, Gary W; Rami, Harshad K; Riley, Graham J; Scott, Claire M; Shaw, Tracey E; Starr, Kathryn R; Stemp, Geoffrey; Thewlis, Kevin M; Thomas, David R; Thompson, Mervyn; Vong, Antonio K K; Watson, Jeannette M

2005-02-01

Starting from a high throughput screening hit, a series of 3,4-dihydro-2H-benzoxazinones has been identified with both high affinity for the 5-HT(1A) receptor and potent 5-HT reuptake inhibitory activity. The 5-(2-methyl)quinolinyloxy derivative combined high 5-HT(1A/1B/1D) receptor affinities with low intrinsic activity and potent inhibition of the 5-HT reuptake site (pK(i)8.2). This compound also had good oral bioavailability and brain penetration in the rat.

Indolyl aryl sulfones (IASs): development of highly potent NNRTIs active against wt-HIV-1 and clinically relevant drug resistant mutants.

PubMed

Silvestri, Romano; Artico, Marino

2005-01-01

Indolyl aryl sulfones (IASs) are a potent class of NNRTIs developed from L-737,126, a lead agent discovered by Merck AG. IAS derivatives are endowed with inhibitory activities against wt HIV-1 in the low nanomolar concentration range. Introduction of two methyl groups at positions 3 and 5 of the phenyl ring of the aryl sulfonyl moiety furnished IAS derivatives such as 5-chloro- or 5-bromo-3-[(3,5-dimethylphenyl)sulfonyl]indole-2-carboxyamide, which showed very potent and selective anti-HIV-1 activity against some mutants carrying NNRTI resistant mutations at positions 103 and 181 of the reverse transcriptase. IAS derivatives bearing 2-hydroxyethylcarboxyamide or 2-hydroxyethylcarboxyhydrazide groups at position 2 of the indole nucleus were more active than L-737,126 against the K103N-Y181C double mutant. A great improvement of antiviral activity against wt HIV-1 and resistant mutants was obtained by coupling 1-3 simple amino acids, such as glycine and alanine, in sequence, with the 3-[(3,5-dimethylphenyl)sulfonyl]-1H-indole-2-carbonyl moiety. The transformation of the chain terminus into amide or hydrazide, produced short peptides with high selectivity and potent activity against wt HIV-1, and the viral mutants Y181C, K103N-Y181C and EFV(R). IAS having two halogen atoms at the indole showed potent inhibitory activity against the Y181C and the EFV(R) resistant mutant strains. In particular, the introduction of a fluorine atom at position 4 of the indole ring notably contributed to improve the antiviral activities against both wt and the related resistant mutants. 5-Nitro-IASs were highly active against wt HIV-1 and exhibited low cytotoxicity. Experimental data highlighted the class IAS derivatives as promising candidates for clinical trials.

A non-cytotoxic N-dehydroabietylamine derivative with potent antimalarial activity.

PubMed

Sadashiva, Maralinganadoddi P; Gowda, Raghavendra; Wu, Xianzhu; Inamdar, Gajanan S; Kuzu, Omer F; Rangappa, Kanchugarakoppal S; Robertson, Gavin P; Gowda, D Channe

2015-08-01

Malaria caused by the Plasmodium parasites continues to be an enormous global health problem owing to wide spread drug resistance of parasites to many of the available antimalarial drugs. Therefore, development of new classes of antimalarial agents is essential to effectively treat malaria. In this study, the efficacy of naturally occurring diterpenoids, dehydroabietylamine and abietic acid, and their synthetic derivatives was assessed for antimalarial activity. Dehydroabietylamine and its N-trifluoroacetyl, N-tribromoacetyl, N-benzoyl, and N-benzyl derivatives showed excellent activity against P. falciparum parasites with IC50 values of 0.36 to 2.6 µM. Interestingly, N-dehydroabietylbenzamide showed potent antimalarial activity (IC50 0.36), and negligible cytotoxicity (IC50 >100 µM) to mammalian cells; thus, this compound can be an important antimalarial drug. In contrast, abietic acid was only marginally effective, exhibiting an IC50 value of ~82 µM. Several carboxylic group-derivatives of abietic acid were moderately active with IC50 values of ~8.2 to ~13.3 µM. These results suggest that a detailed understanding of the structure-activity relationship of abietane diterpenoids might provide strategies to exploit this class of compounds for malaria treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis and SAR studies of potent imidazopyridine anticoccidial agents.

PubMed

Liang, Gui-Bai; Qian, Xiaoxia; Feng, Dennis; Fisher, Michael; Brown, Christine M; Gurnett, Anne; Leavitt, Penny Sue; Liberator, Paul A; Misura, Andrew S; Tamas, Tamas; Schmatz, Dennis M; Wyvratt, Matthew; Biftu, Tesfaye

2007-07-01

Diaryl imidazo[1,2-a]pyridine derivatives, such as 6a and 7i, have been synthesized and found to be potent inhibitors of parasite PKG activity. The most potent compounds are the 7-isopropylaminomethyl analog 6a and 2-isopropylamino analog 7i. These compounds are also fully active in in vivo assay as anticoccidial agents at 25 ppm in feed.

Reorienting the Fab Domains of Trastuzumab Results in Potent HER2 Activators

PubMed Central

Scheer, Justin M.; Sandoval, Wendy; Elliott, J. Michael; Shao, Lily; Luis, Elizabeth; Lewin-Koh, Sock-Cheng; Schaefer, Gabriele; Vandlen, Richard

2012-01-01

The structure of the Fab region of antibodies is critical to their function. By introducing single cysteine substitutions into various positions of the heavy and light chains of the Fab region of trastuzumab, a potent antagonist of HER2, and using thiol chemistry to link the different Fabs together, we produced a variety of monospecific F(ab′)2-like molecules with activities spanning from activation to inhibition of breast tumor cell growth. These isomers (or bis-Fabs) of trastuzumab, with varying relative spatial arrangements between the Fv-regions, were able to either promote or inhibit cell-signaling activities through the PI3K/AKT and MAPK pathways. A quantitative phosphorylation mapping of HER2 indicated that the agonistic isomers produced a distinct phosphorylation pattern associated with activation. This study suggests that antibody geometric isomers, found both in nature and during synthetic antibody development, can have profoundly different biological activities independent of their affinities for their target molecules. PMID:23284778

The HIV-1 transcriptional activator Tat has potent nucleic acid chaperoning activities in vitro.

PubMed

Kuciak, Monika; Gabus, Caroline; Ivanyi-Nagy, Roland; Semrad, Katharina; Storchak, Roman; Chaloin, Olivier; Muller, Sylviane; Mély, Yves; Darlix, Jean-Luc

2008-06-01

The human immunodeficiency virus type 1 (HIV-1) is a primate lentivirus that causes the acquired immunodeficiency syndrome (AIDS). In addition to the virion structural proteins and enzyme precursors, that are Gag, Env and Pol, HIV-1 encodes several regulatory proteins, notably a small nuclear transcriptional activator named Tat. The Tat protein is absolutely required for virus replication since it controls proviral DNA transcription to generate the full-length viral mRNA. Tat can also regulate mRNA capping and splicing and was recently found to interfere with the cellular mi- and siRNA machinery. Because of its extensive interplay with nucleic acids, and its basic and disordered nature we speculated that Tat had nucleic acid-chaperoning properties. This prompted us to examine in vitro the nucleic acid-chaperoning activities of Tat and Tat peptides made by chemical synthesis. Here we report that Tat has potent nucleic acid-chaperoning activities according to the standard DNA annealing, DNA and RNA strand exchange, RNA ribozyme cleavage and trans-splicing assays. The active Tat(44-61) peptide identified here corresponds to the smallest known sequence with DNA/RNA chaperoning properties.

The HIV-1 transcriptional activator Tat has potent nucleic acid chaperoning activities in vitro

PubMed Central

Kuciak, Monika; Gabus, Caroline; Ivanyi-Nagy, Roland; Semrad, Katharina; Storchak, Roman; Chaloin, Olivier; Muller, Sylviane; Mély, Yves; Darlix, Jean-Luc

2008-01-01

The human immunodeficiency virus type 1 (HIV-1) is a primate lentivirus that causes the acquired immunodeficiency syndrome (AIDS). In addition to the virion structural proteins and enzyme precursors, that are Gag, Env and Pol, HIV-1 encodes several regulatory proteins, notably a small nuclear transcriptional activator named Tat. The Tat protein is absolutely required for virus replication since it controls proviral DNA transcription to generate the full-length viral mRNA. Tat can also regulate mRNA capping and splicing and was recently found to interfere with the cellular mi- and siRNA machinery. Because of its extensive interplay with nucleic acids, and its basic and disordered nature we speculated that Tat had nucleic acid-chaperoning properties. This prompted us to examine in vitro the nucleic acid-chaperoning activities of Tat and Tat peptides made by chemical synthesis. Here we report that Tat has potent nucleic acid-chaperoning activities according to the standard DNA annealing, DNA and RNA strand exchange, RNA ribozyme cleavage and trans-splicing assays. The active Tat(44–61) peptide identified here corresponds to the smallest known sequence with DNA/RNA chaperoning properties. PMID:18442994

Synthesis of novel ring-contracted artemisinin dimers with potent anticancer activities.

PubMed

Zhang, Ning; Yu, Zhimei; Yang, Xiaohong; Hu, Ping; He, Yun

2018-04-25

Artemisinin is a potential anticancer agent with an interesting trioxane sesquiterpene structure. In order to improve the biological activity and metabolic stability of artemisinin, a series of novel ring-contracted artemisinin dimers were synthesized. These dimers were evaluated by MTT assay against six cancer cell lines. Most of the dimmers exhibited improved antiproliferative activities over artemisinin. Especially, compound 8b showed the most pronounced anti-cancer activity for PC12 cancer cells with an IC 50 value of 1.56 μM. Thus, PC12 cancer cells were used to further investigate the mechanism of antiproliferation for this series of compounds. Compound 8b arrested cell cycle at G1 phase and induced cell apoptosis via up-regulation of Bad, Bax, caspase-3 and caspase-9 protein expressions while inhibiting the expression of Bcl-xL. The present studies are the first to synthesize the ring-contracted artemisinin as dimers and show that these dimers have potent anti-tumor activities against several cancer cell lines. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Synthesis and SAR of 1-acetanilide-4-aminopyrazole-substituted quinazolines: selective inhibitors of Aurora B kinase with potent anti-tumor activity.

PubMed

Foote, Kevin M; Mortlock, Andrew A; Heron, Nicola M; Jung, Frédéric H; Hill, George B; Pasquet, Georges; Brady, Madeleine C; Green, Stephen; Heaton, Simon P; Kearney, Sarah; Keen, Nicholas J; Odedra, Rajesh; Wedge, Stephen R; Wilkinson, Robert W

2008-03-15

A new class of 1-acetanilide-4-aminopyrazole-substituted quinazoline Aurora kinase inhibitors has been discovered possessing highly potent cellular activity. Continuous infusion into athymic mice bearing SW620 tumors of the soluble phosphate derivative 2 led to dose-proportional exposure of the des-phosphate compound 8 with a high-unbound fraction. The combination of potent cell activity and high free-drug exposure led to pharmacodynamic changes in the tumor at low doses, indicative of Aurora B-kinase inhibition and a reduction in tumor volume.

A Nanocomposite Hydrogel with Potent and Broad-Spectrum Antibacterial Activity.

PubMed

Dai, Tianjiao; Wang, Changping; Wang, Yuqing; Xu, Wei; Hu, Jingjing; Cheng, Yiyun

2018-05-02

Local bacterial infection is a challenging task and still remains a serious threat to human health in clinics. Systemic administration of antibiotics has only short-term antibacterial activity and usually causes adverse effects and bacterial resistance. A bioadhesive hydrogel with broad-spectrum and on-demand antibiotic activity is highly desirable. Here, we designed a pH-responsive nanocomposite hydrogel via a Schiff base linkage between oxidized polysaccharides and cationic dendrimers encapsulated with silver nanoparticles. The antibacterial components, both the cationic dendrimers and silver species, could be released in response to the acidity generated by growing bacteria. The released cationic polymer and silver exhibited a synergistic effect in antibacterial activity, and thus, the nanocomposite hydrogel showed potent antibacterial activity against both Gram-negative ( Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria ( Staphylococcus epidermidis and Staphylococcus aureus). The gel showed superior in vivo antibacterial efficacy against S. aureus infection compared with a commercial silver hydrogel at the same silver concentration. In addition, no obvious hemolytic toxicity, cytotoxicity, and tissue and biochemical toxicity were observed for the antibacterial hydrogel after incubation with cells or implantation. This study provides a facile and promising strategy to develop smart hydrogels to treat local bacterial infections.

Amoxapine Demonstrates Incomplete Inhibition of β-Glucuronidase Activity from Human Gut Microbiota.

PubMed

Yang, Wei; Wei, Bin; Yan, Ru

2018-01-01

Amoxapine has been demonstrated to be a potent inhibitor of Escherichia coli β-glucuronidase. This study aims to explore the factors causing unsatisfactory efficacy of amoxapine in alleviating CPT-11-induced gastrointestinal toxicity in mice and to predict the outcomes in humans. Amoxapine (100 µM) exhibited poor and varied inhibition on β-glucuronidase activity in gut microbiota from 10 healthy individuals and their pool (pool, 11.9%; individuals, 3.6%-54.4%) with IC 50 >100 µM and potent inhibition toward E. coli β-glucuronidase (IC 50 = 0.34 µM). p-Nitrophenol formation from p-nitrophenyl-β-D-glucuronide by pooled and individual gut microbiota fitted classical Michaelis-Menten kinetics, showing similar affinity (K m = 113-189 µM) but varied catalytic capability (V max = 53-556 nmol/h/mg). Interestingly, amoxapine showed distinct inhibitory effects (8.7%-100%) toward β-glucuronidases of 13 bacterial isolates (including four Enterococcus, three Streptococcus, two Escherichia, and two Staphylococcus strains; gus genes belonging to OTU1, 2 or 21) regardless of their genetic similarity or bacterial origin. In addition, amoxapine inhibited the growth of pooled and individual gut microbiota at a high concentration (6.3%-30.8%, 200 µM). Taken together, these findings partly explain the unsatisfactory efficacy of amoxapine in alleviating CPT-11-induced toxicity and predict a poor outcome of β-glucuronidase inhibition in humans, highlighting the necessity of using a human gut microbiota community for drug screening.

Trifluoroacetylated tyrosine-rich D-tetrapeptides have potent antioxidant activity.

PubMed

Sandomenico, Annamaria; Severino, Valeria; Apone, Fabio; De Lucia, Adriana; Caporale, Andrea; Doti, Nunzianna; Russo, Anna; Russo, Rosita; Rega, Camilla; Del Giacco, Tiziana; Falcigno, Lucia; Ruvo, Menotti; Chambery, Angela

2017-03-01

The term "oxidative stress" indicates a set of chemical reactions unleashed by a disparate number of events inducing DNA damage, lipid peroxidation, protein modification and other effects, which are responsible of altering the physiological status of cells or tissues. Excessive Reactive Oxygen Species (ROS) levels may accelerate ageing of tissues or induce damage of biomolecules thus promoting cell death or proliferation in dependence of cell status and of targeted molecules. In this context, new antioxidants preventing such effects may have a relevant role as modulators of cell homeostasis and as therapeutic agents. Following an approach of peptide libraries synthesis and screening by an ORAC FL assay, we have isolated potent anti-oxidant compounds with well-defined structures. Most effective peptides are N-terminally trifluoroacetylated (CF 3 ) and have the sequence tyr-tyr-his-pro or tyr-tyr-pro-his. Slight changes in the sequence or removal of the CF 3 group strongly reduced antioxidant ability, suggesting an active role of both the fluorine atoms and of peptide structure. We have determined the NMR solution structures of the active peptides and found a common structural motif that could underpin the radical scavenging activity. The peptides protect keratinocytes from exogenous oxidation, thereby from potential external damaging cues, suggesting their use as skin ageing protectant and as cell surviving agents. Copyright © 2017 Elsevier Inc. All rights reserved.

Grape seed and tea extracts and catechin 3-gallates are potent inhibitors of α-amylase and α-glucosidase activity.

PubMed

Yilmazer-Musa, Meltem; Griffith, Anneke M; Michels, Alexander J; Schneider, Erik; Frei, Balz

2012-09-12

This study evaluated the inhibitory effects of plant-based extracts (grape seed, green tea, and white tea) and their constituent flavan-3-ol monomers (catechins) on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. To evaluate the relative potency of extracts and catechins, their concentrations required for 50 and 90% inhibition of enzyme activity were determined and compared to the widely used pharmacological glucosidase inhibitor, acarbose. Maximum enzyme inhibition was used to assess relative inhibitory efficacy. Results showed that grape seed extract strongly inhibited both α-amylase and α-glucosidase activity, with equal and much higher potency, respectively, than acarbose. Whereas tea extracts and catechin 3-gallates were less effective inhibitors of α-amylase, they were potent inhibitors of α-glucosidase. Nongallated catechins were ineffective. The data show that plant extracts containing catechin 3-gallates, in particular epigallocatechin gallate, are potent inhibitors of α-glucosidase activity and suggest that procyanidins in grape seed extract strongly inhibit α-amylase activity.

Inhibitors of plasmodial serine hydroxymethyltransferase (SHMT): cocrystal structures of pyrazolopyrans with potent blood- and liver-stage activities.

PubMed

Witschel, Matthias C; Rottmann, Matthias; Schwab, Anatol; Leartsakulpanich, Ubolsree; Chitnumsub, Penchit; Seet, Michael; Tonazzi, Sandro; Schwertz, Geoffrey; Stelzer, Frank; Mietzner, Thomas; McNamara, Case; Thater, Frank; Freymond, Céline; Jaruwat, Aritsara; Pinthong, Chatchadaporn; Riangrungroj, Pinpunya; Oufir, Mouhssin; Hamburger, Matthias; Mäser, Pascal; Sanz-Alonso, Laura M; Charman, Susan; Wittlin, Sergio; Yuthavong, Yongyuth; Chaiyen, Pimchai; Diederich, François

2015-04-09

Several of the enzymes related to the folate cycle are well-known for their role as clinically validated antimalarial targets. Nevertheless for serine hydroxymethyltransferase (SHMT), one of the key enzymes of this cycle, efficient inhibitors have not been described so far. On the basis of plant SHMT inhibitors from an herbicide optimization program, highly potent inhibitors of Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) SHMT with a pyrazolopyran core structure were identified. Cocrystal structures of potent inhibitors with PvSHMT were solved at 2.6 Å resolution. These ligands showed activity (IC50/EC50 values) in the nanomolar range against purified PfSHMT, blood-stage Pf, and liver-stage P. berghei (Pb) cells and a high selectivity when assayed against mammalian cell lines. Pharmacokinetic limitations are the most plausible explanation for lack of significant activity of the inhibitors in the in vivo Pb mouse malaria model.

Conformation-Dependent High-Affinity Potent Ricin-Neutralizing Monoclonal Antibodies

PubMed Central

Hu, Wei-Gang; Yin, Junfei; Chau, Damon; Hu, Charles Chen; Lillico, Dustin; Yu, Justin; Negrych, Laurel M.; Cherwonogrodzky, John W.

2013-01-01

Ricin is a potential biothreat agent with no approved antidote available for ricin poisoning. The aim of this study was to develop potent antibody-based antiricin antidotes. Four strong ricin resistant hybridoma clones secreting antiricin monoclonal antibodies (mAbs) were developed. All four mAbs are bound to conformational epitopes of ricin toxin B (RTB) with high affinity (K D values from 2.55 to 36.27 nM). RTB not only triggers cellular uptake of ricin, but also facilitates transport of the ricin toxin A (RTA) from the endoplasmic reticulum to the cytosol, where RTA exerts its toxic activity. The four mAbs were found to have potent ricin-neutralizing capacities and synergistic effects among them as determined by an in vitro neutralization assay. In vivo protection assay demonstrated that all four mAbs had strong efficacy against ricin challenges. D9 was found to be exceptionally effective. Intraperitoneal (i.p.) administration of D9, at a dose of 5 μg, 6 weeks before or 6 hours after an i.p. challenge with 5 × LD50 of ricin was able to protect or rescue 100% of the mice, indicating that mAb D9 is an excellent candidate to be developed as a potent antidote against ricin poisoning for both prophylactic and therapeutic purposes. PMID:23484120

Ricin-Holotoxin-Based Vaccines: Induction of Potent Ricin-Neutralizing Antibodies.

PubMed

Sabo, Tamar; Kronman, Chanoch; Mazor, Ohad

2016-01-01

Ricin is one of the most potent and lethal toxins known to which there is no available antidote. Currently, the most promising therapy is based on neutralizing antibodies elicited by active vaccination or given passively. Here, detailed protocols are provided for the production of two ricin holotoxin-based vaccines: monomerized subunit-based vaccine, and a formaldehyde-based ricin toxoid vaccine. Both vaccines were found to be stable with no toxic activity reversion even after long-term storage while eliciting high anti-ricin antibody titers possessing a potent neutralizing activity. The use of these vaccines is highly suitable for both the production of sera that can be used in passive protection experiments and immunization aimed to isolate potent anti-ricin monoclonal antibodies.

Demonstration of Active Combustion Control

NASA Technical Reports Server (NTRS)

Lovett, Jeffrey A.; Teerlinck, Karen A.; Cohen, Jeffrey M.

2008-01-01

The primary objective of this effort was to demonstrate active control of combustion instabilities in a direct-injection gas turbine combustor that accurately simulates engine operating conditions and reproduces an engine-type instability. This report documents the second phase of a two-phase effort. The first phase involved the analysis of an instability observed in a developmental aeroengine and the design of a single-nozzle test rig to replicate that phenomenon. This was successfully completed in 2001 and is documented in the Phase I report. This second phase was directed toward demonstration of active control strategies to mitigate this instability and thereby demonstrate the viability of active control for aircraft engine combustors. This involved development of high-speed actuator technology, testing and analysis of how the actuation system was integrated with the combustion system, control algorithm development, and demonstration testing in the single-nozzle test rig. A 30 percent reduction in the amplitude of the high-frequency (570 Hz) instability was achieved using actuation systems and control algorithms developed within this effort. Even larger reductions were shown with a low-frequency (270 Hz) instability. This represents a unique achievement in the development and practical demonstration of active combustion control systems for gas turbine applications.

Withaferin A, a natural compound with anti-tumor activity, is a potent inhibitor of transcription factor C/EBPβ.

PubMed

Falkenberg, Kim D; Jakobs, Anke; Matern, Julian C; Dörner, Wolfgang; Uttarkar, Sagar; Trentmann, Amke; Steinmann, Simone; Coulibaly, Anna; Schomburg, Caroline; Mootz, Henning D; Schmidt, Thomas J; Klempnauer, Karl-Heinz

2017-07-01

Recent work has shown that deregulation of the transcription factor Myb contributes to the development of leukemia and several other human cancers, making Myb and its cooperation partners attractive targets for drug development. By employing a myeloid Myb-reporter cell line we have identified Withaferin A (WFA), a natural compound that exhibits anti-tumor activities, as an inhibitor of Myb-dependent transcription. Analysis of the inhibitory mechanism of WFA showed that WFA is a significantly more potent inhibitor of C/EBPβ, a transcription factor cooperating with Myb in myeloid cells, than of Myb itself. We show that WFA covalently modifies specific cysteine residues of C/EBPβ, resulting in the disruption of the interaction of C/EBPβ with the co-activator p300. Our work identifies C/EBPβ as a novel direct target of WFA and highlights the role of p300 as a crucial co-activator of C/EBPβ. The finding that WFA is a potent inhibitor of C/EBPβ suggests that inhibition of C/EBPβ might contribute to the biological activities of WFA. Copyright © 2017 Elsevier B.V. All rights reserved.

Potent and broad-spectrum antibacterial activity of indole-based bisamidine antibiotics: synthesis and SAR of novel analogs of MBX 1066 and MBX 1090

PubMed Central

Williams, John D.; Nguyen, Son T.; Gu, Shen; Ding, Xiaoyuan; Butler, Michelle M.; Tashjian, Tommy F.; Opperman, Timothy J.; Panchal, Rekha G.; Bavari, Sina; Peet, Norton P.; Moir, Donald T.; Bowlin, Terry L.

2013-01-01

The prevalence of drug-resistant bacteria in the clinic has propelled a concerted effort to find new classes of antibiotics that will circumvent current modes of resistance. We have previously described a set of bisamidine antibiotics that contains a core composed of two indoles and a central linker. The first compounds of the series, MBX 1066 and MBX 1090, have potent antibacterial properties against a wide range of Gram-positive and Gram-negative bacteria. We have conducted a systematic exploration of the amidine functionalities, the central linker, and substituents at the indole 3-position to determine the factors involved in potent antibacterial activity. Some of the newly synthesized compounds have even more potent and broad-spectrum activity than MBX 1066 and MBX 1090. PMID:24239389

Pyrazole derived ultra-short antimicrobial peptidomimetics with potent anti-biofilm activity.

PubMed

Ahn, Mija; Gunasekaran, Pethaiah; Rajasekaran, Ganesan; Kim, Eun Young; Lee, Soo-Jae; Bang, Geul; Cho, Kun; Hyun, Jae-Kyung; Lee, Hyun-Ju; Jeon, Young Ho; Kim, Nam-Hyung; Ryu, Eun Kyoung; Shin, Song Yub; Bang, Jeong Kyu

2017-01-05

In this study, we report on the first chemical synthesis of ultra-short pyrazole-arginine based antimicrobial peptidomimetics derived from the newly synthesized N-alkyl/aryl pyrazole amino acids. Through the systematic tuning of hydrophobicity, charge, and peptide length, we identified the shortest peptide Py11 with the most potent antimicrobial activity. Py11 displayed greater antimicrobial activity against antibiotic-resistant bacteria, including MRSA, MDRPA, and VREF, which was approximately 2-4 times higher than that of melittin. Besides its higher selectivity (therapeutic index) toward bacterial cells than LL-37, Py11 showed highly increased proteolytic stability against trypsin digestion and maintained its antimicrobial activity in the presence of physiological salts. Interestingly, Py11 exhibited higher anti-biofilm activity against MDRPA compared to LL-37. The results from fluorescence spectroscopy and transmission electron microscopy (TEM) suggested that Py11 kills bacterial cells possibly by integrity disruption damaging the cell membrane, leading to the cytosol leakage and eventual cell lysis. Furthermore, Py11 displayed significant anti-inflammatory (endotoxin-neutralizing) activity by inhibiting LPS-induced production of nitric oxide (NO) and TNF-α. Collectively, our results suggest that Py11 may serve as a model compound for the design of antimicrobial and antisepsis agents. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Breast Milk of HIV-Positive Mothers Has Potent and Species-Specific In Vivo HIV-Inhibitory Activity

PubMed Central

Wahl, Angela; Baker, Caroline; Spagnuolo, Rae Ann; Stamper, Lisa W.; Fouda, Genevieve G.; Permar, Sallie R.; Hinde, Katie; Kuhn, Louise; Bode, Lars; Aldrovandi, Grace M.

2015-01-01

ABSTRACT Despite the nutritional and health benefits of breast milk, breast milk can serve as a vector for mother-to-child HIV transmission. Most HIV-infected infants acquire HIV through breastfeeding. Paradoxically, most infants breastfed by HIV-positive women do not become infected. This is potentially attributed to anti-HIV factors in breast milk. Breast milk of HIV-negative women can inhibit HIV infection. However, the HIV-inhibitory activity of breast milk from HIV-positive mothers has not been evaluated. In addition, while significant differences in breast milk composition between transmitting and nontransmitting HIV-positive mothers have been correlated with transmission risk, the HIV-inhibitory activity of their breast milk has not been compared. This knowledge may significantly impact the design of prevention approaches in resource-limited settings that do not deny infants of HIV-positive women the health benefits of breast milk. Here, we utilized bone marrow/liver/thymus humanized mice to evaluate the in vivo HIV-inhibitory activity of breast milk obtained from HIV-positive transmitting and nontransmitting mothers. We also assessed the species specificity and biochemical characteristics of milk's in vivo HIV-inhibitory activity and its ability to inhibit other modes of HIV infection. Our results demonstrate that breast milk of HIV-positive mothers has potent HIV-inhibitory activity and indicate that breast milk can prevent multiple routes of infection. Most importantly, this activity is unique to human milk. Our results also suggest multiple factors in breast milk may contribute to its HIV-inhibitory activity. Collectively, our results support current recommendations that HIV-positive mothers in resource-limited settings exclusively breastfeed in combination with antiretroviral therapy. IMPORTANCE Approximately 240,000 children become infected with HIV annually, the majority via breastfeeding. Despite daily exposure to virus in breast milk, most infants

Potent inhibition of human neutrophil activations by bractelactone, a novel chalcone from Fissistigma bracteolatum

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

Wu, Yang-Chang; Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan; Sureshbabu, Munisamy

Fissistigma bracteolatum is widely used in traditional medicine to treat inflammatory diseases. However, its active components and mechanisms of action remain unclear. In this study, (3Z)-6,7-dihydroxy-4-methoxy-3-(phenylmethylidene)-5-(3-phenylpropanoyl) -1-benzofuran-2(3H) (bractelactone), a novel chalcone from F. bracteolatum, showed potent inhibitory effects against superoxide anion (O{sub 2}{sup ·−}) production, elastase release, and CD11b expression in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-induced human neutrophils. However, bractelactone showed only weak inhibition of phorbol myristate acetate-caused O{sub 2}{sup ·−} production. The peak cytosolic calcium concentration ([Ca{sup 2+}]{sub i}) was unaltered by bractelactone in FMLP-induced neutrophils, but the decay time of [Ca{sup 2+}]{sub i} was significantly shortened. In a calcium-free solution, changesmore » in [Ca{sup 2+}]{sub i} caused by the addition of extracellular Ca{sup 2+} were inhibited by bractelactone in FMLP-activated cells. In addition, bractelactone did not alter the phosphorylation of p38 MAPK, ERK, JNK, or AKT or the concentration of cAMP. These results suggest that bractelactone selectively inhibits store-operated calcium entry (SOCE). In agreement with this concept, bractelactone suppressed sustained [Ca{sup 2+}]{sub i} changes in thapsigargin-activated neutrophils. Furthermore, bractelactone did not alter FMLP-induced formation of inositol 1,4,5-triphosphate. Taken together, our results demonstrate that the anti-inflammatory effects of bractelactone, an active ingredient of F. bracteolatum, in human neutrophils are through the selective inhibition of SOCE. Highlights: ► Bractelactone isolated from Fissistigma bracteolatum. ► Bractelactone inhibited FMLP-induced human neutrophil activations. ► Bractelactone had no effect on IP3 formation. ► Bractelactone did not alter MAPKs, AKT, and cAMP pathways. ► Bractelactone inhibited store-operated calcium entry.« less

Discovery of a potent and highly specific β2 proteasome inhibitor from a library of copper complexes.

PubMed

Zhou, Tongliang; Cai, Yuanbo; Liang, Lei; Yang, Lingfei; Xu, Fengrong; Niu, Yan; Wang, Chao; Zhang, Jun-Long; Xu, Ping

2016-12-01

We reported the synthesis, characterization and biological activity of several copper(II) Schiff base complexes, which exhibit high proteasome inhibitory activities with particular selectivity of β 2 subunit. Structure-activity relationships information obtained from complex Na 2 [Cu(a4s1)] demonstrated that distinct bonding modes in β 2 and β 5 subunits determines its selectivity and potent inhibition for β 2 subunit. Copyright © 2016 Elsevier Ltd. All rights reserved.

SCH 206272: a potent, orally active tachykinin NK(1), NK(2), and NK(3) receptor antagonist.

PubMed

Anthes, John C; Chapman, Richard W; Richard, Christian; Eckel, Stephen; Corboz, Michel; Hey, John A; Fernandez, Xiomara; Greenfeder, Scott; McLeod, Robbie; Sehring, Susan; Rizzo, Charles; Crawley, Yvette; Shih, Neng-Yang; Piwinski, John; Reichard, Greg; Ting, Pauline; Carruthers, Nick; Cuss, Francis M; Billah, Motasim; Kreutner, William; Egan, Robert W

2002-08-23

Experiments were performed to characterize the pharmacology of SCH 206272 [(R,R)-1'[5-[(3,5-dichlorobenzoyl)methylamino]-3-(3,4-dichlorophenyl)-4(Z)-(methoxyimino)pentyl]-N-methyl-2-oxo-[1,4'bipiperidine]-3-acetamide] as a potent and selective antagonist of tachykinin (NK) NK(1), NK(2), and NK(3) receptors. SCH 206272 inhibited binding at human tachykinin NK(1), NK(2), and NK(3) receptors (K(i) = 1.3, 0.4, and 0.3 nM, respectively) and antagonized [Ca(2+)](i) mobilization in Chinese hamster ovary (CHO) cells expressing the cloned human tachykinin NK(1), NK(2), or NK(3) receptors. SCH 206272 inhibited relaxation of the human pulmonary artery (pK(b) = 7.7 +/- 0.3) induced by the tachykinin NK(1) receptor agonist, [Met-O-Me] substance P and contraction of the human bronchus (pK(b = 8.2 +/- 0.3) induced by the tachykinin NK(2) receptor agonist, neurokinin A. In isolated guinea pig tissues, SCH 206272 inhibited substance P-induced enhancement of electrical field stimulated contractions of the vas deferens, (pK(b = 7.6 +/- 0.2), NKA-induced contraction of the bronchus (pK(b) = 7.7 +/- 0.2), and senktide-induced contraction of the ileum. In vivo, oral SCH 206272 (0.1-10 mg/kg, p.o.) inhibited substance P-induced airway microvascular leakage and neurokinin A-induced bronchospasm in the guinea pig. In a canine in vivo model, SCH 206272 (0.1-3 mg/kg, p.o.) inhibited NK(1) and NK(2) activities induced by exogenous substance P and neurokinin A. Furthermore, in guinea pig models involving endogenously released tachykinins, SCH 206272 inhibited hyperventilation-induced bronchospasm, capsaicin-induced cough, and airway microvascular leakage induced by nebulized hypertonic saline. These data demonstrate that SCH 206272 is a potent, orally active tachykinin NK(1), NK(2), and NK(3) receptor antagonist. This compound may have beneficial effects in diseases thought to be mediated by tachykinins, such as cough, asthma, and chronic obstructive pulmonary disease. Copyright 2002 Elsevier

New Pyrazolopyrimidine Inhibitors of Protein Kinase D as Potent Anticancer Agents for Prostate Cancer Cells

PubMed Central

Tandon, Manuj; Johnson, James; Li, Zhihong; Xu, Shuping; Wipf, Peter; Wang, Qiming Jane

2013-01-01

The emergence of protein kinase D (PKD) as a potential therapeutic target for several diseases including cancer has triggered the search for potent, selective, and cell-permeable small molecule inhibitors. In this study, we describe the identification, in vitro characterization, structure-activity analysis, and biological evaluation of a novel PKD inhibitory scaffold exemplified by 1-naphthyl PP1 (1-NA-PP1). 1-NA-PP1 and IKK-16 were identified as pan-PKD inhibitors in a small-scale targeted kinase inhibitor library assay. Both screening hits inhibited PKD isoforms at about 100 nM and were ATP-competitive inhibitors. Analysis of several related kinases indicated that 1-NA-PP1 was highly selective for PKD as compared to IKK-16. SAR analysis showed that 1-NA-PP1 was considerably more potent and showed distinct substituent effects at the pyrazolopyrimidine core. 1-NA-PP1 was cell-active, and potently blocked prostate cancer cell proliferation by inducing G2/M arrest. It also potently blocked the migration and invasion of prostate cancer cells, demonstrating promising anticancer activities on multiple fronts. Overexpression of PKD1 or PKD3 almost completely reversed the growth arrest and the inhibition of tumor cell invasion caused by 1-NA-PP1, indicating that its anti-proliferative and anti-invasive activities were mediated through the inhibition of PKD. Interestingly, a 12-fold increase in sensitivity to 1-NA-PP1 could be achieved by engineering a gatekeeper mutation in the active site of PKD1, suggesting that 1-NA-PP1 could be paired with the analog-sensitive PKD1M659G for dissecting PKD-specific functions and signaling pathways in various biological systems. PMID:24086585

Phenazine antibiotic inspired discovery of potent bromophenazine antibacterial agents against Staphylococcus aureus and Staphylococcus epidermidis.

PubMed

Borrero, Nicholas V; Bai, Fang; Perez, Cristian; Duong, Benjamin Q; Rocca, James R; Jin, Shouguang; Huigens, Robert W

2014-02-14

Nearly all clinically used antibiotics have been (1) discovered from microorganisms (2) using phenotype screens to identify inhibitors of bacterial growth. The effectiveness of these antibiotics is attributed to their endogenous roles as bacterial warfare agents against competing microorganisms. Unfortunately, every class of clinically used antibiotic has been met with drug resistant bacteria. In fact, the emergence of resistant bacterial infections coupled to the dismal pipeline of new antibacterial agents has resulted in a global health care crisis. There is an urgent need for innovative antibacterial strategies and treatment options to effectively combat drug resistant bacterial pathogens. Here, we describe the implementation of a Pseudomonas competition strategy, using redox-active phenazines, to identify novel antibacterial leads against Staphylococcus aureus and Staphylococcus epidermidis. In this report, we describe the chemical synthesis and evaluation of a diverse 27-membered phenazine library. Using this microbial warfare inspired approach, we have identified several bromophenazines with potent antibacterial activities against S. aureus and S. epidermidis. The most potent bromophenazine analogue from this focused library demonstrated a minimum inhibitory concentration (MIC) of 0.78-1.56 μM, or 0.31-0.62 μg mL(-1), against S. aureus and S. epidermidis and proved to be 32- to 64-fold more potent than the phenazine antibiotic pyocyanin in head-to-head MIC experiments. In addition to the discovery of potent antibacterial agents against S. aureus and S. epidermidis, we also report a detailed structure-activity relationship for this class of bromophenazine small molecules.

The discovery of thienopyridine analogues as potent IkappaB kinase beta inhibitors. Part II.

PubMed

Wu, Jiang-Ping; Fleck, Roman; Brickwood, Janice; Capolino, Alison; Catron, Katrina; Chen, Zhidong; Cywin, Charles; Emeigh, Jonathan; Foerst, Melissa; Ginn, John; Hrapchak, Matt; Hickey, Eugene; Hao, Ming-Hong; Kashem, Mohammed; Li, Jun; Liu, Weimin; Morwick, Tina; Nelson, Richard; Marshall, Daniel; Martin, Leslie; Nemoto, Peter; Potocki, Ian; Liuzzi, Michel; Peet, Gregory W; Scouten, Erika; Stefany, David; Turner, Michael; Weldon, Steve; Zimmitti, Clare; Spero, Denise; Kelly, Terence A

2009-10-01

An SAR study that identified a series of thienopyridine-based potent IkappaB Kinase beta (IKKbeta) inhibitors is described. With focuses on the structural optimization at C4 and C6 of structure 1 (Fig. 1), the study reveals that small alkyl and certain aromatic groups are preferred at C4, whereas polar groups with proper orientation at C6 efficiently enhance compound potency. The most potent analogues inhibit IKKbeta with IC50s as low as 40 nM, suppress LPS-induced TNF-alpha production in vitro and in vivo, display good kinase selectivity profiles, and are active in a HeLa cell NF-kappaB reporter gene assay, demonstrating that they directly interfere with the NF-kappaB signaling pathway.

2-Arylbenzofurans from Artocarpus lakoocha and methyl ether analogs with potent cholinesterase inhibitory activity.

PubMed

Namdaung, Umalee; Athipornchai, Anan; Khammee, Thongchai; Kuno, Mayuso; Suksamrarn, Sunit

2018-01-01

In vitro screening for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of the Artocarpus lakoocha root-bark extracts revealed interesting results. Bioassay-guided fractionation resulted in the isolation of two new (1 and 2) and six known 2-arylbenzofurans 3-8, along with one stilbenoid 9 and one flavonoid 10. The structures of the isolated compounds were elucidated by UV, IR, 1D- and 2D-NMR and MS spectroscopic data analysis. Compounds 4, 6 and 7 exhibited more potent AChE inhibitory activity (IC 50  = 0.87-1.10 μM) than the reference drug, galantamine. Compounds 4, 8 and 9 displayed greater BChE inhibition than the standard drug. The preferential inhibition of BChE over AChE indicated that 4 also showed a promising dual AChE and BChE inhibitor. The synthetic mono-methylated analogs 4a-c and 6a-b were found to be good BChE inhibitors with IC 50 values ranging between 0.31 and 1.11 μM. Based on the docking studies, compounds 4 and 6 are well-fitted in the catalytic triad of AChE. Compounds 4 and 6 showed different binding orientations on BChE, and the most potent BChE inhibitor 4 occupied dual binding to both CAS and PAS more efficiently. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Substituted 4-carboxymethylpyroglutamic acid diamides as potent and selective inhibitors of fibroblast activation protein.

PubMed

Tsai, Ting-Yueh; Yeh, Teng-Kuang; Chen, Xin; Hsu, Tsu; Jao, Yu-Chen; Huang, Chih-Hsiang; Song, Jen-Shin; Huang, Yu-Chen; Chien, Chia-Hui; Chiu, Jing-Huai; Yen, Shih-Chieh; Tang, Hung-Kuan; Chao, Yu-Sheng; Jiaang, Weir-Torn

2010-09-23

Fibroblast activation protein (FAP) belongs to the prolyl peptidase family. FAP inhibition is expected to become a new antitumor target. Most known FAP inhibitors often resemble the dipeptide cleavage products, with a boroproline at the P1 site; however, these inhibitors also inhibit DPP-IV, DPP-II, DPP8, and DPP9. Potent and selective FAP inhibitor is needed in evaluating that FAP as a therapeutic target. Therefore, it is important to develop selective FAP inhibitors for the use of target validation. To achieve this, optimization of the nonselective DPP-IV inhibitor 8 led to the discovery of a new class of substituted 4-carboxymethylpyroglutamic acid diamides as FAP inhibitors. SAR studies resulted in a number of FAP inhibitors having IC(50) of <100 nM with excellent selectivity over DPP-IV, DPP-II, DPP8, and DPP9 (IC(50) > 100 μM). Compounds 18a, 18b, and 19 are the only known potent and selective FAP inhibitors, which prompts us to further study the physiological role of FAP.

A natural inhibitor of kidney-type glutaminase: a withanolide from Physalis pubescens with potent anti-tumor activity

PubMed Central

Wu, Canrong; Zheng, Mengzhu; Gao, Suyu; Luan, Shanshan; Cheng, Li; Wang, Liqing; Li, Jiachen; Chen, Lixia; Li, Hua

2017-01-01

Kidney-type glutaminase (KGA), a mitochondrial enzyme converting glutamine to glutamate for energy supply, was over-expressed in many cancers and had been regarded as a promising therapeutic target in recent years. Structure-based virtual ligand screening predicted physapubescin K, a new withanolide from Physalis pubescens, to be potential KGA inhibitor. Enzyme activity inhibition assays and microscale thermophoresis experiments had demonstrated the efficiency and specificity of physapubescin K targeting KGA. Additionally, physapubescin K exhibited potent proliferation inhibitory effects on a panel of human cancer cell lines, such as SW1990 and HCC827-ER. It blocked glutamine metabolism in SW1990 with increasing intracellular level of glutamine and decreasing glutamate and its downstream metabolites. Physapubescin K also significantly inhibited the tumor growth in a SW1990 xenograft mouse model. Interestingly, physapubescin K could reverse the resistance of HCC827-ER cells to erlotinib and synergize with the hexokinase 2 inhibitor to markedly enhance the inhibition of SW1990 cell proliferation. PMID:29371926

A potent synthetic inorganic antibiotic with activity against drug-resistant pathogens.

PubMed

Hubick, Shelby; Jayaraman, Arumugam; McKeen, Alexander; Reid, Shelby; Alcorn, Jane; Stavrinides, John; Sterenberg, Brian T

2017-02-06

The acronymously named "ESKAPE" pathogens represent a group of bacteria that continue to pose a serious threat to human health, not only due to their propensity for repeated emergence, but also due to their ability to "eskape" antibiotic treatment. The evolution of multi-drug resistance in these pathogens alone has greatly outpaced the development of new therapeutics, necessitating an alternative strategy for antibiotic development that considers the evolutionary mechanisms driving antibiotic resistance. In this study, we synthesize a novel inorganic antibiotic, phosphopyricin, which has antibiotic activity against the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE). We show that this potent antibiotic is bactericidal, and exhibits low toxicity in an acute dose assay in mice. As a synthetic compound that does not occur naturally, phosphopyricin would be evolutionarily foreign to microbes, thereby slowing the evolution of resistance. In addition, it loses antibiotic activity upon exposure to light, meaning that the active antibiotic will not accumulate in the general environment where strong selective pressures imposed by antibiotic residuals are known to accelerate resistance. Phosphopyricin represents an innovation in antimicrobials, having a synthetic core, and a photosensitive chemical architecture that would reduce accumulation in the environment.

New Pyrrole Derivatives with Potent Tubulin Polymerization Inhibiting Activity As Anticancer Agents Including Hedgehog-Dependent Cancer

PubMed Central

La Regina, Giuseppe; Bai, Ruoli; Coluccia, Antonio; Famiglini, Valeria; Pelliccia, Sveva; Passacantilli, Sara; Mazzoccoli, Carmela; Ruggieri, Vitalba; Sisinni, Lorenza; Bolognesi, Alessio; Rensen, Whilelmina Maria; Miele, Andrea; Nalli, Marianna; Alfonsi, Romina; Di Marcotullio, Lucia; Gulino, Alberto; Brancale, Andrea; Novellino, Ettore; Dondio, Giulio; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Hamel, Ernest; Lavia, Patrizia; Silvestri, Romano

2014-01-01

We synthesized 3-aroyl-1-arylpyrrole (ARAP) derivatives as potential anticancer agents having different substituents at the pendant 1-phenyl ring. Both the 1-phenyl ring and 3-(3,4,5-trimethoxyphenyl)carbonyl moieties were mandatory to achieve potent inhibition of tubulin polymerization, binding of colchicine to tubulin, and cancer cell growth. ARAP 22 showed strong inhibition of the P-glycoprotein-overexpressing NCI-ADR-RES and Messa/Dx5MDR cell lines. Compounds 22 and 27 suppressed in vitro the Hedgehog signaling pathway, strongly reducing luciferase activity in SAG treated NIH3T3 Shh-Light II cells, and inhibited the growth of medulloblastoma D283 cells at nanomolar concentrations. ARAPs 22 and 27 represent a new potent class of tubulin polymerization and cancer cell growth inhibitors with the potential to inhibit the Hedgehog signaling pathway. PMID:25025991

Enteromorpha compressa Exhibits Potent Antioxidant Activity

PubMed Central

Shanab, Sanaa M. M.; Shalaby, Emad A.; El-Fayoumy, Eman A.

2011-01-01

The green macroalgae, Enteromorpha compressa (Linnaeus) Nees, Ulva lactuca, and E. linza, were seasonally collected from Abu Qir bay at Alexandria (Mediterranean Sea) This work aimed to investigate the seasonal environmental conditions, controlling the green algal growth, predominance, or disappearance and determining antioxidant activity. The freshly collected selected alga (E. compressa) was subjected to pigment analysis (chlorophyll and carotenoids) essential oil and antioxidant enzyme determination (ascorbate oxidase and catalase). The air-dried ground alga was extracted with ethanol (crude extract) then sequentially fractionated by organic solvents of increasing polarity (petroleum ether, chloroform, ethyl acetate, and water). Antioxidant activity of all extracts was assayed using different methods (total antioxidant, DPPH [2, 2 diphenyl-1-picrylhydrazyl], ABTS [2, 2 azino-bis ethylbenzthiazoline-6-sulfonic acid], and reducing power, and β-carotene linoleic acid bleaching methods). The results indicated that the antioxidant activity was concentration and time dependent. Ethyl acetate fraction demonstrated higher antioxidant activity against DPPH method (82.80%) compared to the synthetic standard butylated hydroxyl toluene (BHT, 88.5%). However, the crude ethanolic extract, pet ether, chloroform fractions recorded lower to moderate antioxidant activities (49.0, 66.0, and 78.0%, resp.). Using chromatographic and spectroscopic analyses, an active compound was separated and identified from the promising ethyl acetate fraction. PMID:21869863

Isolation and Characterization of an Endophytic Fungal Strain with Potent Antimicrobial and Termiticidal Activities From Port-Orford-Cedar.

PubMed

Sun, Liqing; Hse, Chung-Yun; Shupe, Todd; Sun, Mingjing; Wang, Xiaohua; Zhao, Kai

2015-06-01

Termites are responsible for an estimated US$1 billion annually in property damage, repairs, pest control, and prevention. There is an urgent need of finding a better alternative way to control and prevent termites. Port-Orford-Cedar (POC) has been known to have significant levels of natural durability and termiticidal activities due to its extractive contents. In this study, 25 endophytes including 22 fungal and 3 bacterial strains were isolated from the POC. Four strains, namely, HDZK-BYF21, HDZK-BYF1, HDZK-BYF2, and HDZK-BYB11, were chosen to test their termiticidal activities. The fermentation broth of strain HDZK-BYF21 displayed the potent antimicrobial and termiticidal activities. Morphological examination and 18 S rDNA sequence analysis demonstrated that strain HDZK-BYF21 belonged to the genus Aspergillus. This finding indicates the existence of an interesting chemical symbiosis between an endophytic fungus and its host. This is also the first report on endophytes isolated from the POC that may have potential termiticidal activities. Endophytes with termiticidal activities can be grown in bioreactor to provide an inexhaustible supply of bioactive compounds and thus can be exploited commercially. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

P1-Substituted Symmetry-Based Human Immunodeficiency Virus Protease Inhibitors with Potent Antiviral Activity against Drug-Resistant Viruses

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

DeGoey, David A.; Grampovnik, David J.; Chen, Hui-Ju

2013-03-07

Because there is currently no cure for HIV infection, patients must remain on long-term drug therapy, leading to concerns over potential drug side effects and the emergence of drug resistance. For this reason, new and safe antiretroviral agents with improved potency against drug-resistant strains of HIV are needed. A series of HIV protease inhibitors (PIs) with potent activity against both wild-type (WT) virus and drug-resistant strains of HIV was designed and synthesized. The incorporation of substituents with hydrogen bond donor and acceptor groups at the P1 position of our symmetry-based inhibitor series resulted in significant potency improvements against the resistantmore » mutants. By this approach, several compounds, such as 13, 24, and 29, were identified that demonstrated similar or improved potencies compared to 1 against highly mutated strains of HIV derived from patients who previously failed HIV PI therapy. Overall, compound 13 demonstrated the best balance of potency against drug resistant strains of HIV and oral bioavailability in pharmacokinetic studies. X-ray analysis of an HIV PI with an improved resistance profile bound to WT HIV protease is also reported.« less

Anticancer copper(II) phosphorus dendrimers are potent proapoptotic Bax activators.

PubMed

Mignani, Serge; El Brahmi, Nabil; Eloy, Laure; Poupon, Joel; Nicolas, Valérie; Steinmetz, Anke; El Kazzouli, Said; Bousmina, Mosto M; Blanchard-Desce, Mireille; Caminade, Anne-Marie; Majoral, Jean-Pierre; Cresteil, Thierry

2017-05-26

A multivalent phosphorus dendrimer 1G 3 and its corresponding Cu-complex, 1G 3 -Cu have been recently identified as agents retaining high antiproliferative potency. This antiproliferative capacity was preserved in cell lines overexpressing the efflux pump ABC B1, whereas cross-resistance was observed in ovarian cancer cell lines resistant to cisplatin. Theoretical 3D models were constructed: the dendrimers appear as irregularly shaped disk-like nano-objects of about 22 Å thickness and 49 Å diameter, which accumulated in cells after penetration by endocytosis. To get insight in their mode of action, cell death pathways have been examined in human cancer cell lines: early apoptosis was followed by secondary necrosis after multivalent phosphorus dendrimers exposure. The multivalent plain phosphorus dendrimer 1G 3 moderately activated caspase-3 activity, in contrast with the multivalent Cu-conjugated phosphorus dendrimer 1G 3 -Cu which strikingly reduced the caspase-3 content and activity. This decrease of caspase activity is not related to the presence of copper, since inorganic copper has no or little effect on caspase-3. Conversely the potent apoptosis activation could be related to a noticeable translocation of Bax to the mitochondria, resulting in the release of AIF into the cytosol, its translocation to the nucleus and a severe DNA fragmentation, without alteration of the cell cycle. The multivalent Cu-conjugated phosphorus dendrimer is more efficient than its non-complexed analog to activate this pathway in close relationship with the higher antiproliferative potency. Therefore, this multivalent Cu-conjugated phosphorus dendrimer 1G 3 -Cu can be considered as a new and promising first-in-class antiproliferative agent with a distinctive mode of action, inducing apoptosis tumor cell death through Bax activation pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Design and synthesis of aloe-emodin derivatives as potent anti-tyrosinase, antibacterial and anti-inflammatory agents.

PubMed

Liu, Jinbing; Wu, Fengyan; Chen, Changhong

2015-11-15

Twenty aloe-emodin derivatives were designed, synthesized, and their biological activities were evaluated. Some compounds displayed potent tyrosinase inhibitory activities, especially, compounds with thiosemicarbazide moiety showed more potent inhibitory effects than the other compounds. The structure-activity relationships (SARs) were preliminarily discussed. The inhibition mechanism of selected compounds 1 and 13 were investigated. The results showed compound 1 was reversible inhibitor, however, compound 13 was irreversible. Kinetic analysis indicated that compound 1 was competitive tyrosinase inhibitor. Furthermore, the antibacterial activities and anti-inflammatory activities of some selected compounds were also screened. The results showed that compound 3 exhibited more potent antibacterial activity than the aloe-emodin, compounds 5 and 6 possessed more potent anti-inflammatory activities than the diacerein. Copyright © 2015 Elsevier Ltd. All rights reserved.

Discovery of a tetrahydropyrimidin-2(1H)-one derivative (TAK-442) as a potent, selective, and orally active factor Xa inhibitor.

PubMed

Fujimoto, Takuya; Imaeda, Yasuhiro; Konishi, Noriko; Hiroe, Katsuhiko; Kawamura, Masaki; Textor, Garret P; Aertgeerts, Kathleen; Kubo, Keiji

2010-05-13

Coagulation enzyme factor Xa (FXa) is a particularly promising target for the development of new anticoagulant agents. We previously reported the imidazo[1,5-c]imidazol-3-one derivative 1 as a potent and orally active FXa inhibitor. However, it was found that 1 predominantly undergoes hydrolysis upon incubation with human liver microsomes, and the human specific metabolic pathway made it difficult to predict the human pharmacokinetics. To address this issue, our synthetic efforts were focused on modification of the imidazo[1,5-c]imidazol-3-one moiety of the active metabolite 3a, derived from 1, which resulted in the discovery of the tetrahydropyrimidin-2(1H)-one derivative 5k as a highly potent and selective FXa inhibitor. Compound 5k showed no detectable amide bond cleavage in human liver microsomes, exhibited a good pharmacokinetic profile in monkeys, and had a potent antithrombotic efficacy in a rabbit model without prolongation of bleeding time. Compound 5k is currently under clinical development with the code name TAK-442.

Exploring the anti-cancer activity of novel thiosemicarbazones generated through the combination of retro-fragments: dissection of critical structure-activity relationships.

PubMed

Serda, Maciej; Kalinowski, Danuta S; Rasko, Nathalie; Potůčková, Eliška; Mrozek-Wilczkiewicz, Anna; Musiol, Robert; Małecki, Jan G; Sajewicz, Mieczysław; Ratuszna, Alicja; Muchowicz, Angelika; Gołąb, Jakub; Simůnek, Tomáš; Richardson, Des R; Polanski, Jaroslaw

2014-01-01

Thiosemicarbazones (TSCs) are an interesting class of ligands that show a diverse range of biological activity, including anti-fungal, anti-viral and anti-cancer effects. Our previous studies have demonstrated the potent in vivo anti-tumor activity of novel TSCs and their ability to overcome resistance to clinically used chemotherapeutics. In the current study, 35 novel TSCs of 6 different classes were designed using a combination of retro-fragments that appear in other TSCs. Additionally, di-substitution at the terminal N4 atom, which was previously identified to be critical for potent anti-cancer activity, was preserved through the incorporation of an N4-based piperazine or morpholine ring. The anti-proliferative activity of the novel TSCs were examined in a variety of cancer and normal cell-types. In particular, compounds 1d and 3c demonstrated the greatest promise as anti-cancer agents with potent and selective anti-proliferative activity. Structure-activity relationship studies revealed that the chelators that utilized "soft" donor atoms, such as nitrogen and sulfur, resulted in potent anti-cancer activity. Indeed, the N,N,S donor atom set was crucial for the formation of redox active iron complexes that were able to mediate the oxidation of ascorbate. This further highlights the important role of reactive oxygen species generation in mediating potent anti-cancer activity. Significantly, this study identified the potent and selective anti-cancer activity of 1d and 3c that warrants further examination.

A potent, covalent inhibitor of orotidine 5'-monophosphate decarboxylase with antimalarial activity.

PubMed

Bello, Angelica M; Poduch, Ewa; Fujihashi, Masahiro; Amani, Merhnaz; Li, Yan; Crandall, Ian; Hui, Raymond; Lee, Ping I; Kain, Kevin C; Pai, Emil F; Kotra, Lakshmi P

2007-03-08

Orotidine 5'-monophosphate decarboxylase (ODCase) has evolved to catalyze the decarboxylation of orotidine 5'-monophosphate without any covalent intermediates. Active site residues in ODCase are involved in an extensive hydrogen-bonding network. We discovered that 6-iodouridine 5'-monophosphate (6-iodo-UMP) irreversibly inhibits the catalytic activities of ODCases from Methanobacterium thermoautotrophicum and Plasmodium falciparum. Mass spectral analysis of the enzyme-inhibitor complex confirms covalent attachment of the inhibitor to ODCase accompanied by the loss of two protons and the iodo moiety. The X-ray crystal structure (1.6 A resolution) of the complex of the inhibitor and ODCase clearly shows the covalent bond formation with the active site Lys-72 [corrected] residue. 6-Iodo-UMP inhibits ODCase in a time- and concentration-dependent fashion. 6-Iodouridine, the nucleoside form of 6-iodo-UMP, exhibited potent antiplasmodial activity, with IC50s of 4.4 +/- 1.3 microM and 6.2 +/- 0.7 microM against P. falciparum ItG and 3D7 isolates, respectively. 6-Iodouridine 5'-monophosphate is a novel covalent inhibitor of ODCase, and its nucleoside analogue paves the way to a new class of inhibitors against malaria.

Simultaneous inhibition of multiple oncogenic miRNAs by a multi-potent microRNA sponge.

PubMed

Jung, Jaeyun; Yeom, Chanjoo; Choi, Yeon-Sook; Kim, Sinae; Lee, EunJi; Park, Min Ji; Kang, Sang Wook; Kim, Sung Bae; Chang, Suhwan

2015-08-21

The roles of oncogenic miRNAs are widely recognized in many cancers. Inhibition of single miRNA using antagomiR can efficiently knock-down a specific miRNA. However, the effect is transient and often results in subtle phenotype, as there are other miRNAs contribute to tumorigenesis. Here we report a multi-potent miRNA sponge inhibiting multiple miRNAs simultaneously. As a model system, we targeted miR-21, miR-155 and miR-221/222, known as oncogenic miRNAs in multiple tumors including breast and pancreatic cancers. To achieve efficient knockdown, we generated perfect and bulged-matched miRNA binding sites (MBS) and introduced multiple copies of MBS, ranging from one to five, in the multi-potent miRNA sponge. Luciferase reporter assay showed the multi-potent miRNA sponge efficiently inhibited 4 miRNAs in breast and pancreatic cancer cells. Furthermore, a stable and inducible version of the multi-potent miRNA sponge cell line showed the miRNA sponge efficiently reduces the level of 4 target miRNAs and increase target protein level of these oncogenic miRNAs. Finally, we showed the miRNA sponge sensitize cells to cancer drug and attenuate cell migratory activity. Altogether, our study demonstrates the multi-potent miRNA sponge is a useful tool to examine the functional impact of simultaneous inhibition of multiple miRNAs and proposes a therapeutic potential.

Hydroxychavicol: a potent xanthine oxidase inhibitor obtained from the leaves of betel, Piper betle.

PubMed

Murata, Kazuya; Nakao, Kikuyo; Hirata, Noriko; Namba, Kensuke; Nomi, Takao; Kitamura, Yoshihisa; Moriyama, Kenzo; Shintani, Takahiro; Iinuma, Munekazu; Matsuda, Hideaki

2009-07-01

The screening of Piperaceous plants for xanthine oxidase inhibitory activity revealed that the extract of the leaves of Piper betle possesses potent activity. Activity-guided purification led us to obtain hydroxychavicol as an active principle. Hydroxychavicol is a more potent xanthine oxidase inhibitor than allopurinol, which is clinically used for the treatment of hyperuricemia.

Masitinib (AB1010), a Potent and Selective Tyrosine Kinase Inhibitor Targeting KIT

PubMed Central

Dubreuil, Patrice; Letard, Sébastien; Ciufolini, Marco; Gros, Laurent; Humbert, Martine; Castéran, Nathalie; Borge, Laurence; Hajem, Bérengère; Lermet, Anne; Sippl, Wolfgang; Voisset, Edwige; Arock, Michel; Auclair, Christian; Leventhal, Phillip S.; Mansfield, Colin D.; Moussy, Alain; Hermine, Olivier

2009-01-01

Background The stem cell factor receptor, KIT, is a target for the treatment of cancer, mastocytosis, and inflammatory diseases. Here, we characterise the in vitro and in vivo profiles of masitinib (AB1010), a novel phenylaminothiazole-type tyrosine kinase inhibitor that targets KIT. Methodology/Principal Findings In vitro, masitinib had greater activity and selectivity against KIT than imatinib, inhibiting recombinant human wild-type KIT with an half inhibitory concentration (IC50) of 200±40 nM and blocking stem cell factor-induced proliferation and KIT tyrosine phosphorylation with an IC50 of 150±80 nM in Ba/F3 cells expressing human or mouse wild-type KIT. Masitinib also potently inhibited recombinant PDGFR and the intracellular kinase Lyn, and to a lesser extent, fibroblast growth factor receptor 3. In contrast, masitinib demonstrated weak inhibition of ABL and c-Fms and was inactive against a variety of other tyrosine and serine/threonine kinases. This highly selective nature of masitinib suggests that it will exhibit a better safety profile than other tyrosine kinase inhibitors; indeed, masitinib-induced cardiotoxicity or genotoxicity has not been observed in animal studies. Molecular modelling and kinetic analysis suggest a different mode of binding than imatinib, and masitinib more strongly inhibited degranulation, cytokine production, and bone marrow mast cell migration than imatinib. Furthermore, masitinib potently inhibited human and murine KIT with activating mutations in the juxtamembrane domain. In vivo, masitinib blocked tumour growth in mice with subcutaneous grafts of Ba/F3 cells expressing a juxtamembrane KIT mutant. Conclusions Masitinib is a potent and selective tyrosine kinase inhibitor targeting KIT that is active, orally bioavailable in vivo, and has low toxicity. PMID:19789626

Potent Plasmodium falciparum gametocytocidal activity of diaminonaphthoquinones, lead antimalarial chemotypes identified in an antimalarial compound screen.

PubMed

Tanaka, Takeshi Q; Guiguemde, W Armand; Barnett, David S; Maron, Maxim I; Min, Jaeki; Connelly, Michele C; Suryadevara, Praveen Kumar; Guy, R Kiplin; Williamson, Kim C

2015-03-01

Forty percent of the world's population is threatened by malaria, which is caused by Plasmodium parasites and results in an estimated 200 million clinical cases and 650,000 deaths each year. Drug resistance has been reported for all commonly used antimalarials and has prompted screens to identify new drug candidates. However, many of these new candidates have not been evaluated against the parasite stage responsible for transmission, gametocytes. If Plasmodium falciparum gametocytes are not eliminated, patients continue to spread malaria for weeks after asexual parasite clearance. Asymptomatic individuals can also harbor gametocyte burdens sufficient for transmission, and a safe, effective gametocytocidal agent could also be used in community-wide malaria control programs. Here, we identify 15 small molecules with nanomolar activity against late-stage gametocytes. Fourteen are diaminonaphthoquinones (DANQs), and one is a 2-imino-benzo[d]imidazole (IBI). One of the DANQs identified, SJ000030570, is a lead antimalarial candidate. In contrast, 94% of the 650 compounds tested are inactive against late-stage gametocytes. Consistent with the ineffectiveness of most approved antimalarials against gametocytes, of the 19 novel compounds with activity against known anti-asexual-stage targets, only 3 had any strong effect on gametocyte viability. These data demonstrate the distinct biology of the transmission stages and emphasize the importance of screening for gametocytocidal activity. The potent gametocytocidal activity of DANQ and IBI coupled with their efficacy against asexual parasites provides leads for the development of antimalarials with the potential to prevent both the symptoms and the spread of malaria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Dihydroorotate dehydrogenase inhibitor F901318 has potent in vitro activity against Scedosporium species and Lomentospora prolificans.

PubMed

Wiederhold, Nathan P; Law, Derek; Birch, Michael

2017-07-01

Scedosporium species and Lomentospora prolificans are increasing causes of invasive infections in immunocompromised hosts and many isolates are resistant to available antifungals. Our objective was to assess the in vitro potency of F901318, a member of the orotomide class of antifungals, against Scedosporium species and L. prolificans . The in vitro potency of F901318 was evaluated against 66 Scedosporium and 7 L. prolificans clinical isolates using the CLSI M38-A2 reference standard. Scedosporium species included Scedosporium apiospermum ( n  =   43), Scedosporium aurantiacum ( n  =   6), Scedosporium dehoogii ( n  =   2) and Scedosporium boydii ( n  =   15). Positive comparators included amphotericin B, caspofungin, posaconazole and voriconazole. Against S. apiospermum and S. boydii F901318 geometric mean MICs/MECs (0.079 and 0.046 mg/L, respectively) were significantly lower than those observed with amphotericin (3.404 and 5.595 mg/L), posaconazole (1.937 and 1.823 mg/L), voriconazole (0.784 and 0.630 mg/L) and caspofungin (5.703 and 7.639 mg/L) ( P  <   0.001). Against S. aurantiacum and S. dehoogii the F901318 MIC range (0.12-0.5 mg/L) was also lower than those for the other antifungals (0.5 to >8 mg/L). F901318 also maintained activity against L. prolificans isolates (range 0.12-0.25 mg/L) in contrast to other antifungals, of which none demonstrated in vitro activity. F901318 demonstrated potent in vitro activity against Scedosporium species and L. prolificans . This activity was maintained against isolates that had significantly reduced susceptibility to the other antifungals. Further studies are warranted to evaluate the in vivo efficacy of F901318 against Scedosporium species and L. prolificans . © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A potent synthetic inorganic antibiotic with activity against drug-resistant pathogens

PubMed Central

Hubick, Shelby; Jayaraman, Arumugam; McKeen, Alexander; Reid, Shelby; Alcorn, Jane; Stavrinides, John; Sterenberg, Brian T.

2017-01-01

The acronymously named “ESKAPE” pathogens represent a group of bacteria that continue to pose a serious threat to human health, not only due to their propensity for repeated emergence, but also due to their ability to “eskape” antibiotic treatment12. The evolution of multi-drug resistance in these pathogens alone has greatly outpaced the development of new therapeutics, necessitating an alternative strategy for antibiotic development that considers the evolutionary mechanisms driving antibiotic resistance. In this study, we synthesize a novel inorganic antibiotic, phosphopyricin, which has antibiotic activity against the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE). We show that this potent antibiotic is bactericidal, and exhibits low toxicity in an acute dose assay in mice. As a synthetic compound that does not occur naturally, phosphopyricin would be evolutionarily foreign to microbes, thereby slowing the evolution of resistance. In addition, it loses antibiotic activity upon exposure to light, meaning that the active antibiotic will not accumulate in the general environment where strong selective pressures imposed by antibiotic residuals are known to accelerate resistance. Phosphopyricin represents an innovation in antimicrobials, having a synthetic core, and a photosensitive chemical architecture that would reduce accumulation in the environment. PMID:28165020

Adenosine A2A receptor agonists with potent antiplatelet activity.

PubMed

Fuentes, Eduardo; Fuentes, Manuel; Caballero, Julio; Palomo, Iván; Hinz, Sonja; El-Tayeb, Ali; Müller, Christa E

2018-05-01

Selected adenosine A 2A receptor agonists (PSB-15826, PSB-12404, and PSB-16301) have been evaluated as new antiplatelet agents. In addition, radioligand-binding studies and receptor-docking experiments were performed in order to explain their differential biological effects on a molecular level. Among the tested adenosine derivatives, PSB-15826 was the most potent compound to inhibit platelet aggregation (EC 50 0.32 ± 0.05 µmol/L) and platelet P-selectin cell-surface localization (EC 50 0.062 ± 0.2 µmol/L), and to increase intraplatelets cAMP levels (EC 50 0.24 ± 0.01 µmol/L). The compound was more active than CGS21680 (EC 50 0.97±0.07 µmol/L) and equipotent to NECA (EC 50 0.31 ± 0.05 µmol/L) in platelet aggregation induced by ADP. In contrast to the results from cAMP assays, K i values determined in radioligand-binding studies were not predictive of the A 2A agonists' antiplatelet activity. Docking studies revealed the key molecular determinants of this new family of adenosine A 2A receptor agonists: differences in activities are related to π-stacking interactions between the ligands and the residue His264 in the extracellular loop of the adenosine A 2A receptor which may result in increased residence times. In conclusion, these results provide an improved understanding of the requirements of antiplatelet adenosine A 2A receptor agonists.

Plasminogen binding inhibitors demonstrate unwanted activities on GABAA and glycine receptors in human iPSC derived neurons.

PubMed

Kristensson, Lisbeth; Lundin, Anders; Gustafsson, David; Fryklund, Jan; Fex, Tomas; Louise, Delsing; Ryberg, Erik

2018-05-11

Plasminogen binding inhibitors (PBIs) reduce the risk of bleeding in hemorrhagic conditions. However, generic PBIs are also associated with an increased risk of seizures, an adverse effect linked to unwanted activities towards inhibitory neuronal receptors. Development of novel PBIs serve to remove compounds with such properties, but progress is limited by a lack of higher throughput methods with human translatability. Herein we apply human induced pluripotent stem cell (hiPSC) derived neurons in combination with dynamic mass redistribution (DMR) technology to demonstrate robust and reproducible modulation of both GABA A and glycine receptors. These cells respond to GABA (EC 50 0.33 ± 0.18 μM), glycine (EC 50 11.0 ± 3.7 μM) and additional ligands in line with previous reports from patch clamp technologies. Additionally, we identify and characterize a competitive antagonistic behavior of the prototype inhibitor and drug tranexamic acid (TXA). Finally, we demonstrate proof of concept for effective counter-screening of lead series compounds towards unwanted GABA A receptor activities. No activity was observed for a previously identified PBI candidate drug, AZD6564, whereas a discontinued analog, AZ13267257, could be characterized as a potent GABA A receptor agonist. Copyright © 2018. Published by Elsevier B.V.

Discovery of potent and selective cytotoxic activity of new quinazoline-ureas against TMZ-resistant glioblastoma multiforme (GBM).

PubMed

Elkamhawy, Ahmed; Viswanath, Ambily Nath Indu; Pae, Ae Nim; Kim, Hyeon Young; Heo, Jin-Chul; Park, Woo-Kyu; Lee, Chong-Ock; Yang, Heekyoung; Kim, Kang Ho; Nam, Do-Hyun; Seol, Ho Jun; Cho, Heeyeong; Roh, Eun Joo

2015-10-20

Herein, we report new quinazoline-urea based compounds with potent cytotoxic activities against TMZ-resistant glioblastoma multiforme (GBM) cells. Low micromolar IC₅₀ values were exhibited over a panel of three primary GBM patient-derived cell cultures belonging to proneural (GBM-1), mesenchymal (GBM-2), and classical (GBM-3) subtypes. Eight compounds showed excellent selectivity indices for GBM cells comparing to a normal astrocyte cell line. In JC-1 assay, analogues 11, 12, 20, 22, and 24 exerted promising rates of mPTP opening induction towards proneural GBM subtype. Compounds 11, 20, and 24 bound to the translocator protein 18 kDa (TSPO) in submicromolar range using [(3)H] PK-11195 binding affinity assay. A homology model was built and docked models of 11, 12, 20, 22 and 24 were generated for describing their plausible binding modes in TSPO. In 3D clonogenic assay, compound 20 manifested potent tumoricidal effects on TMZ-resistant GBM cells even at submicromolar concentrations. In addition, CYP450 and hERG assays presented a safe toxicity profile of 20. Taken as a whole, this report presents compound 20 as a potent, selective and safe GBM cytotoxic agent which constitutes a promising direction against TMZ-resistant GBM. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Structure-activity relationship investigation for benzonaphthyridinone derivatives as novel potent Bruton's tyrosine kinase (BTK) irreversible inhibitors.

PubMed

Wang, Beilei; Deng, Yuanxin; Chen, Yongfei; Yu, Kailin; Wang, Aoli; Liang, Qianmao; Wang, Wei; Chen, Cheng; Wu, Hong; Hu, Chen; Miao, Weili; Hur, Wooyoung; Wang, Wenchao; Hu, Zhenquan; Weisberg, Ellen L; Wang, Jinhua; Ren, Tao; Wang, Yinsheng; Gray, Nathanael S; Liu, Qingsong; Liu, Jing

2017-09-08

Through a structure-based drug design approach, a tricyclic benzonaphthyridinone pharmacophore was used as a starting point for carrying out detailed medicinal structure-activity relationhip (SAR) studies geared toward characterization of a panel of proposed BTK inhibitors, including 6 (QL-X-138), 7 (BMX-IN-1) and 8 (QL47). These studies led to the discovery of the novel potent irreversible BTK inhibitor, compound 18 (CHMFL-BTK-11). Kinetic analysis of compound 18 revealed an irreversible binding efficacy (k inact /K i ) of 0.01 μM -1 s -1 . Compound 18 potently inhibited BTK kinase Y223 auto-phosphorylation (EC 50  < 100 nM), arrested cell cycle in G0/G1 phase, and induced apoptosis in Ramos, MOLM13 and Pfeiffer cells. We believe these features would make 18 a good pharmacological tool for studying BTK-related pathologies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Identification and characterisation of carnostatine (SAN9812), a potent and selective carnosinase (CN1) inhibitor with in vivo activity.

PubMed

Qiu, Jiedong; Hauske, Sibylle J; Zhang, Shiqi; Rodriguez-Niño, Angelica; Albrecht, Thomas; Pastene, Diego O; van den Born, Jacob; van Goor, Harry; Ruf, Sven; Kohlmann, Markus; Teufel, Michael; Krämer, Bernhard K; Hammes, Hans-Peter; Peters, Verena; Yard, Benito A; Kannt, Aimo

2018-06-20

Carnosinase 1 (CN1) has been postulated to be a susceptibility factor for developing diabetic nephropathy (DN). Although its major substrate, carnosine, is beneficial in rodent models of DN, translation of these findings to humans has been hampered by high CN1 activity in human serum resulting in rapid degradation of carnosine. To overcome this hurdle, we screened a protease-directed small-molecule library for inhibitors of human recombinant CN1. We identified SAN9812 as a potent and highly selective inhibitor of CN1 activity with a K i of 11 nM. It also inhibited CN1 activity in human serum and serum of transgenic mice-overexpressing human CN1. Subcutaneous administration of 30 mg/kg SAN9812 led to a sustained reduction in circulating CN1 activity in human CN1 transgenic (TG) mice. Simultaneous administration of carnosine and SAN9812 increased carnosine levels in plasma and kidney by up to 100-fold compared to treatment-naïve CN1-overexpressing mice. To our knowledge, this is the first study reporting on a potent and selective CN1 inhibitor with in vivo activity. SAN9812, also called carnostatine, may be used to increase renal carnosine concentration as a potential therapeutic modality for renal diseases linked to glycoxidative conditions.

Cadmium is a potent inhibitor of PPM phosphatases and targets the M1 binding site

PubMed Central

Pan, Chang; Liu, Hong-Da; Gong, Zheng; Yu, Xiao; Hou, Xu-Ben; Xie, Di-Dong; Zhu, Xi-Bin; Li, Hao-Wen; Tang, Jun-Yi; Xu, Yun-Fei; Yu, Jia-Qi; Zhang, Lian-Ying; Fang, Hao; Xiao, Kun-Hong; Chen, Yu-Guo; Wang, Jiang-Yun; Pang, Qi; Chen, Wei; Sun, Jin-Peng

2013-01-01

The heavy metal cadmium is a non-degradable pollutant. By screening the effects of a panel of metal ions on the phosphatase activity, we unexpectedly identified cadmium as a potent inhibitor of PPM1A and PPM1G. In contrast, low micromolar concentrations of cadmium did not inhibit PP1 or tyrosine phosphatases. Kinetic studies revealed that cadmium inhibits PPM phosphatases through the M1 metal ion binding site. In particular, the negative charged D441 in PPM1G specific recognized cadmium. Our results suggest that cadmium is likely a potent inhibitor of most PPM family members except for PHLPPs. Furthermore, we demonstrated that cadmium inhibits PPM1A-regulated MAPK signaling and PPM1G-regulated AKT signaling potently in vivo. Cadmium reversed PPM1A-induced cell cycle arrest and cadmium insensitive PPM1A mutant rescued cadmium induced cell death. Taken together, these findings provide a better understanding of the effects of the toxicity of cadmium in the contexts of human physiology and pathology. PMID:23903585

Small dense HDLs display potent vasorelaxing activity, reflecting their elevated content of sphingosine-1-phosphate.

PubMed

Perségol, Laurence; Darabi, Maryam; Dauteuille, Carolane; Lhomme, Marie; Chantepie, Sandrine; Rye, Kerry-Anne; Therond, Patrice; Chapman, M John; Salvayre, Robert; Nègre-Salvayre, Anne; Lesnik, Philippe; Monier, Serge; Kontush, Anatol

2018-01-01

The functional heterogeneity of HDL is attributed to its diverse bioactive components. We evaluated whether the vasodilatory effects of HDL differed across HDL subpopulations, reflecting their distinct molecular composition. The capacity of five major HDL subfractions to counteract the inhibitory effects of oxidized LDL on acetylcholine-induced vasodilation was tested in a rabbit aortic rings model. NO production, an essential pathway in endothelium-dependent vasorelaxation, was studied in simian vacuolating virus 40-transformed murine endothelial cells (SVECs). Small dense HDL3 subfractions displayed potent vasorelaxing activity (up to +31% vs. baseline, P < 0.05); in contrast, large light HDL2 did not induce aortic-ring relaxation when compared on a total protein basis. HDL3 particles were enriched with sphingosine-1-phosphate (S1P) (up to 3-fold vs. HDL2), with the highest content in HDL3b and -3c that concomitantly revealed the strongest vasorelaxing properties. NO generation was enhanced by HDL3c in SVECs (1.5-fold, P < 0.01), a phenomenon that was blocked by the S1P receptor antagonist, VPC 23019. S1P-enriched reconstituted HDL (rHDL) was a 1.8-fold ( P < 0.01) more potent vasorelaxant than control rHDL in aortic rings. Small dense HDL3 particles displayed potent protective effects against oxidative stress-associated endothelium dysfunction, potentially reflecting their elevated content of S1P that might facilitate interaction with S1P receptors and ensuing NO generation. Copyright © 2018 by the American Society for Biochemistry and Molecular Biology, Inc.

MIV-150 and zinc acetate combination provides potent and broad activity against HIV-1.

PubMed

Mizenina, Olga; Hsu, Mayla; Jean-Pierre, Ninochka; Aravantinou, Meropi; Levendosky, Keith; Paglini, Gabriela; Zydowsky, Thomas M; Robbiani, Melissa; Fernández-Romero, José A

2017-12-01

We previously showed that the combination of the non-nucleoside reverse transcriptase inhibitor (NNRTI) MIV-150 with zinc acetate (ZA) formulated in a carrageenan (CG; MZC) gel provided macaques significant protection against vaginal simian-human immunodeficiency virus-RT (SHIV-RT) challenge, better than either MIV-150/CG or ZA/CG. The MZC gel was shown to be safe in a phase 1 clinical trial. Herein, we used in vitro approaches to study the antiviral properties of ZA and the MIV-150/ZA combination, compared to other NNRTIs. Like other NNRTIs, MIV-150 has EC 50 values in the subnanomolar to nanomolar range against wild type and NNRTI or RT-resistant HIVs. While less potent than NNRTIs, ZA was shown to be active in primary cells against laboratory-adapted and primary HIV-1 isolates and HIV-1 isolates/clones with NNRTI and RT resistance mutations, with EC 50 values between 20 and 110 μM. The MIV-150/ZA combination had a potent and broad antiviral activity in primary cells. In vitro resistance selection studies revealed that previously described NNRTI-resistant mutations were selected by MIV-150. ZA-resistant virus retained susceptibility to MIV-150 (and other RTIs) and MIV-150-selected virus remained sensitive to ZA. Notably, resistant virus was not selected when cultured in the presence of both ZA and MIV-150. This underscores the potency and breadth of the MIV-150/ZA combination, supporting preclinical macaque studies and the advancement of MZC microbicides into clinical testing.

The Antipancreatic Cancer Activity of OSI-027, a Potent and Selective Inhibitor of mTORC1 and mTORC2

PubMed Central

Chen, Bo; Xu, Ming; Zhang, Hui; Xu, Ming-zheng; Wang, Xu-jing; Tang, Qing-he

2015-01-01

In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin (mTOR) complex 1/2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells both in vitro and in vivo. We demonstrated that OSI-027 inhibited survival and growth of both primary and transformed (PANC-1 and MIA PaCa-2 lines) human pancreatic cancer cells. Meanwhile, OSI-027 induced caspase-dependent apoptotic death of the pancreatic cancer cells. On the other hand, caspase inhibitors alleviated cytotoxicity by OSI-027. At the molecular level, OSI-027 treatment blocked mTORC1 and mTORC2 activation simultaneously, without affecting ERK–mitogen-activated protein kinase activation. Importantly, OSI-027 activated cytoprotective autophagy in the above cancer cells. Whereas pharmacological blockage of autophagy or siRNA knockdown of Beclin-1 significantly enhanced the OSI-027-induced activity against pancreatic cancer cells. Specifically, a relatively low dose of OSI-027 sensitized gemcitabine-induced pancreatic cancer cell death in vitro. Further, administration of OSI-027 or together with gemcitabine dramatically inhibited PANC-1 xenograft growth in severe combined immunodeficiency mice, leading to significant mice survival improvement. In summary, the preclinical results of this study suggest that targeting mTORC1/2 synchronously by OSI-027 could be further investigated as a valuable treatment for pancreatic cancer. PMID:26284306

The Antipancreatic Cancer Activity of OSI-027, a Potent and Selective Inhibitor of mTORC1 and mTORC2.

PubMed

Chen, Bo; Xu, Ming; Zhang, Hui; Xu, Ming-zheng; Wang, Xu-jing; Tang, Qing-he; Tang, Jian-ying

2015-10-01

In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin (mTOR) complex 1/2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells both in vitro and in vivo. We demonstrated that OSI-027 inhibited survival and growth of both primary and transformed (PANC-1 and MIA PaCa-2 lines) human pancreatic cancer cells. Meanwhile, OSI-027 induced caspase-dependent apoptotic death of the pancreatic cancer cells. On the other hand, caspase inhibitors alleviated cytotoxicity by OSI-027. At the molecular level, OSI-027 treatment blocked mTORC1 and mTORC2 activation simultaneously, without affecting ERK-mitogen-activated protein kinase activation. Importantly, OSI-027 activated cytoprotective autophagy in the above cancer cells. Whereas pharmacological blockage of autophagy or siRNA knockdown of Beclin-1 significantly enhanced the OSI-027-induced activity against pancreatic cancer cells. Specifically, a relatively low dose of OSI-027 sensitized gemcitabine-induced pancreatic cancer cell death in vitro. Further, administration of OSI-027 or together with gemcitabine dramatically inhibited PANC-1 xenograft growth in severe combined immunodeficiency mice, leading to significant mice survival improvement. In summary, the preclinical results of this study suggest that targeting mTORC1/2 synchronously by OSI-027 could be further investigated as a valuable treatment for pancreatic cancer.

Demonstration of a potent RET transcriptional inhibitor for the treatment of medullary thyroid carcinoma based on an ellipticine derivative

PubMed Central

Kumarasamy, Vishnu Muthuraj; Sun, Daekyu

2017-01-01

Dominant-activating mutations in the RET (rearranged during transfection) proto-oncogene, which encodes a receptor tyrosine kinase, is often associated with the development of medullary thyroid carcinoma (MTC). The proximal promoter region of the RET gene consists of a guanine-rich sequence containing five runs of three consecutive guanine residues that serve as the binding site for transcriptional factors. As we have recently shown, this stretch of nucleotides in the promoter region is highly dynamic in nature and tend to form non-B DNA secondary structures called G-quadruplexes, which suppress the transcription of the RET gene. In the present study, ellipticine and its derivatives were identified as excellent RET G-quadruplex stabilizing agents. Circular dichroism (CD) spectroscopic studies revealed that the incorporation of a piperidine ring in an ellipticine derivative, NSC311153 improves its binding with the G-quadruplex structure and the stability induced by this compound is more potent than ellipticine. Furthermore, this compound also interfered with the transcriptional mechanism of the RET gene in an MTC derived cell line, TT cells and significantly decreased the endogenous RET protein expression. We demonstrated the specificity of NSC311153 by using papillary thyroid carcinoma (PTC) cells, the TPC1 cell line which lacks the G-quadruplex forming sequence in the promoter region due to chromosomal rearrangement. The RET downregulation selectively suppresses cell proliferation by inhibiting the intracellular Raf/MEK/ERK and PI3K/Akt/mTOR signaling pathways in the TT cells. In the present study, we also showed that the systemic administration of a water soluble NSC311153 analog in a mouse MTC xenograft model inhibited the tumor growth through RET downregulation. PMID:28498409

Halogenated Phenazines that Potently Eradicate Biofilms, MRSA Persister Cells in Non-Biofilm Cultures, and Mycobacterium tuberculosis.

PubMed

Garrison, Aaron T; Abouelhassan, Yasmeen; Kallifidas, Dimitris; Bai, Fang; Ukhanova, Maria; Mai, Volker; Jin, Shouguang; Luesch, Hendrik; Huigens, Robert W

2015-12-01

Conventional antibiotics are ineffective against non-replicating bacteria (for example, bacteria within biofilms). We report a series of halogenated phenazines (HP), inspired by marine antibiotic 1, that targets persistent bacteria. HP 14 demonstrated the most potent biofilm eradication activities to date against MRSA, MRSE, and VRE biofilms (MBEC = 0.2-12.5 μM), as well as the effective killing of MRSA persister cells in non-biofilm cultures. Frontline MRSA treatments, vancomycin and daptomycin, were unable to eradicate MRSA biofilms or non-biofilm persisters alongside 14. HP 13 displayed potent antibacterial activity against slow-growing M. tuberculosis (MIC = 3.13 μM), the leading cause of death by bacterial infection around the world. HP analogues effectively target persistent bacteria through a mechanism that is non-toxic to mammalian cells and could have a significant impact on treatments for chronic bacterial infections. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potentized Mercuric chloride and Mercuric iodide enhance alpha-amylase activity in vitro.

PubMed

Sukul, N C; De, A; Sukul, A; Sinhababu, S P

2002-10-01

Mercuric chloride 30c and Mercuric iodide 30c were prepared by successive dilution in 30 steps of 1:100 followed by sonication at 20KHz for 30s at each step. Both were prepared in two media: 90% ethanol and distilled water. Three preparations of Mercuric chloride 30 in water were used: 12-month old, 1-month old and 4-day old. The controls for the water and ethanol-water preparations were pure water 30c and 90% ethanol 30c, respectively. For the three water preparations there were three matched controls of water 30c of the same ages. Each potentized substance or its control was mixed with distilled water 1:100 before testing. Hydrolysis of starch by alpha-amylase was measured by the standard procedure after incubation for 15 min at 27 degrees C. Mercuric chloride 30c and Mercuric iodide 30c in both water and aqueous ethanol media, enhanced enzyme activity significantly, compared to their respective controls. Mercuric chloride 30c, prepared in water 12 months previously, produced no significant change in the enzyme activity compared to its control. We hypothesize that the structure of the active molecule imprinted on water polymers during the process of dynamization. The specifically structured water interacts with the active sites of alpha-amylase, modifying its activity. Ethanol molecules have large non-polar part stabilizing the water structure and thus retaining activity for a longer time.

Malassezia yeasts produce a collection of exceptionally potent activators of the Ah (dioxin) receptor detected in diseased human skin

PubMed Central

Magiatis, Prokopios; Pappas, Periklis; Gaitanis, George; Mexia, Nikitia; Melliou, Eleni; Galanou, Maria; Vlachos, Christophoros; Stathopoulou, Konstantina; Skaltsounis, Alexios Leandros; Marselos, Marios; Velegraki, Aristea; Denison, Michael S.; Bassukas, Ioannis D.

2013-01-01

Malassezia yeasts are commensal microorganisms which under insufficiently understood conditions can become pathogenic. We have previously shown that specific strains isolated from diseased human skin can preferentially produce agonists of the aryl hydrocarbon receptor (AhR), whose activation has been linked to certain skin diseases. Investigation of skin scale extracts from patients with Malassezia associated diseases demonstrated 10–1000 fold higher AhR activating capacity than control skin extracts. LC/MS/MS analysis of the patients’ extracts revealed the presence of indirubin, 6-formylindolo[3,2-b]carbazole (FICZ), indolo[3,2-b]carbazole (ICZ), malassezin, and pityriacitrin. The same compounds were also identified in 9/12 Malassezia species culture extracts tested, connecting their presence in skin scales with this yeast. Studying the activity of the Malassezia culture-extracts and pure metabolites in HaCaT cells by Reverse Transcriptase Real-Time PCR revealed significant alterations in mRNA levels of the endogenous AhR-responsive genes Cyp1A1, Cyp1B1 and AhRR. Indirubin and FICZ activated AhR in HaCaT and human HepG2 cells with significantly higher, yet transient, potency as compared to the prototypical AhR ligand, dioxin. In loco synthesis of these highly potent AhR inducers by Malassezia yeasts could have a significant impact on skin homeostatic mechanisms and disease development. PMID:23448877

Malassezia yeasts produce a collection of exceptionally potent activators of the Ah (dioxin) receptor detected in diseased human skin.

PubMed

Magiatis, Prokopios; Pappas, Periklis; Gaitanis, George; Mexia, Nikitia; Melliou, Eleni; Galanou, Maria; Vlachos, Christophoros; Stathopoulou, Konstantina; Skaltsounis, Alexios Leandros; Marselos, Marios; Velegraki, Aristea; Denison, Michael S; Bassukas, Ioannis D

2013-08-01

Malassezia yeasts are commensal microorganisms, which under insufficiently understood conditions can become pathogenic. We have previously shown that specific strains isolated from diseased human skin can preferentially produce agonists of the aryl hydrocarbon receptor (AhR), whose activation has been linked to certain skin diseases. Investigation of skin scale extracts from patients with Malassezia-associated diseases demonstrated 10- to 1,000-fold higher AhR-activating capacity than control skin extracts. Liquid chromatography-tandem mass spectrometry analysis of the patients' extracts revealed the presence of indirubin, 6-formylindolo[3,2-b]carbazole (FICZ), indolo[3,2-b]carbazole (ICZ), malassezin, and pityriacitrin. The same compounds were also identified in 9 out of 12 Malassezia species culture extracts tested, connecting their presence in skin scales with this yeast. Studying the activity of the Malassezia culture extracts and pure metabolites in HaCaT cells by reverse transcriptase real-time PCR revealed significant alterations in mRNA levels of the endogenous AhR-responsive genes Cyp1A1, Cyp1B1, and AhRR. Indirubin- and FICZ-activated AhR in HaCaT and human HepG2 cells with significantly higher, yet transient, potency as compared with the prototypical AhR ligand, dioxin. In loco synthesis of these highly potent AhR inducers by Malassezia yeasts could have a significant impact on skin homeostatic mechanisms and disease development.

Target Residence Time-Guided Optimization on TTK Kinase Results in Inhibitors with Potent Anti-Proliferative Activity.

PubMed

Uitdehaag, Joost C M; de Man, Jos; Willemsen-Seegers, Nicole; Prinsen, Martine B W; Libouban, Marion A A; Sterrenburg, Jan Gerard; de Wit, Joeri J P; de Vetter, Judith R F; de Roos, Jeroen A D M; Buijsman, Rogier C; Zaman, Guido J R

2017-07-07

The protein kinase threonine tyrosine kinase (TTK; also known as Mps1) is a critical component of the spindle assembly checkpoint and a promising drug target for the treatment of aggressive cancers, such as triple negative breast cancer. While the first TTK inhibitors have entered clinical trials, little is known about how the inhibition of TTK with small-molecule compounds affects cellular activity. We studied the selective TTK inhibitor NTRC 0066-0, which was developed in our own laboratory, together with 11 TTK inhibitors developed by other companies, including Mps-BAY2b, BAY 1161909, BAY 1217389 (Bayer), TC-Mps1-12 (Shionogi), and MPI-0479605 (Myrexis). Parallel testing shows that the cellular activity of these TTK inhibitors correlates with their binding affinity to TTK and, more strongly, with target residence time. TTK inhibitors are therefore an example where target residence time determines activity in in vitro cellular assays. X-ray structures and thermal stability experiments reveal that the most potent compounds induce a shift of the glycine-rich loop as a result of binding to the catalytic lysine at position 553. This "lysine trap" disrupts the catalytic machinery. Based on these insights, we developed TTK inhibitors, based on a (5,6-dihydro)pyrimido[4,5-e]indolizine scaffold, with longer target residence times, which further exploit an allosteric pocket surrounding Lys553. Their binding mode is new for kinase inhibitors and can be classified as hybrid Type I/Type III. These inhibitors have very potent anti-proliferative activity that rivals classic cytotoxic therapy. Our findings will open up new avenues for more applications for TTK inhibitors in cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Organotins Are Potent Activators of PPARγ and Adipocyte Differentiation in Bone Marrow Multipotent Mesenchymal Stromal Cells

PubMed Central

Yanik, Susan C.; Baker, Amelia H.; Mann, Koren K.; Schlezinger, Jennifer J.

2011-01-01

Adipocyte differentiation in bone marrow is potentially deleterious to both bone integrity and lymphopoiesis. Here, we examine the hypothesis that organotins, common environmental contaminants that are dual ligands for peroxisome proliferator–activated receptor (PPAR) γ and its heterodimerization partner retinoid X receptor (RXR), are potent activators of bone marrow adipogenesis. A C57Bl/6-derived bone marrow multipotent mesenchymal stromal cell (MSC) line, BMS2, was treated with rosiglitazone, a PPARγ agonist, bexarotene, an RXR agonist, or a series of organotins. Rosiglitazone and bexarotene potently activated adipocyte differentiation; however, bexarotene had a maximal efficacy of only 20% of that induced by rosiglitazone. Organotins (tributyltin [TBT], triphenyltin, and dibutyltin) also stimulated adipocyte differentiation (EC50 of 10–20nM) but with submaximal, structure-dependent efficacy. In coexposures, both bexarotene and TBT enhanced rosiglitazone-induced adipogenesis. To investigate the contribution of PPARγ to TBT-induced adipogenesis, we examined expression of PPARγ2, as well as its transcriptional target FABP4. TBT-induced PPARγ2 and FABP4 protein expression with an efficacy intermediate between rosiglitazone and bexarotene, similar to lipid accumulation. A PPARγ antagonist and PPARγ-specific small hairpin RNA suppressed TBT-induced differentiation, although to a lesser extent than rosiglitazone-induced differentiation, suggesting that TBT may engage alternate pathways. TBT and bexarotene, but not rosiglitazone, also induced the expression of TGM2 (an RXR target) and ABCA1 (a liver X receptor target). The results show that an environmental contaminant, acting with the same potency as a therapeutic drug, induces PPARγ-dependent adipocyte differentiation in bone marrow MSCs. Activation of multiple nuclear receptor pathways by organotins may have significant implications for bone physiology. PMID:21622945

Substituted 2H-isoquinolin-1-one as potent Rho-Kinase inhibitors. Part 1: Hit-to-lead account.

PubMed

Wu, Frank; Büttner, Frank H; Chen, Rhonda; Hickey, Eugene; Jakes, Scott; Kaplita, Paul; Kashem, Mohammed A; Kerr, Steven; Kugler, Stanley; Paw, Zofia; Prokopowicz, Anthony; Shih, Cheng-Kon; Snow, Roger; Young, Erick; Cywin, Charles L

2010-06-01

Two closely related scaffolds were identified through an uHTS campaign as desirable starting points for the development of Rho-Kinase (ROCK) inhibitors. Here, we describe our hit-to-lead evaluation process which culminated in the rapid discovery of potent leads such as 22 which successfully demonstrated an early in vivo proof of concept for anti-hypertensive activity. Copyright 2010 Elsevier Ltd. All rights reserved.

Structure-Based Design and Synthesis of Potent and Selective Matrix Metalloproteinase 13 Inhibitors.

PubMed

Choi, Jun Yong; Fuerst, Rita; Knapinska, Anna M; Taylor, Alexander B; Smith, Lyndsay; Cao, Xiaohang; Hart, P John; Fields, Gregg B; Roush, William R

2017-07-13

We describe the use of comparative structural analysis and structure-guided molecular design to develop potent and selective inhibitors (10d and (S)-17b) of matrix metalloproteinase 13 (MMP-13). We applied a three-step process, starting with a comparative analysis of the X-ray crystallographic structure of compound 5 in complex with MMP-13 with published structures of known MMP-13·inhibitor complexes followed by molecular design and synthesis of potent but nonselective zinc-chelating MMP inhibitors (e.g., 10a and 10b). After demonstrating that the pharmacophores of the chelating inhibitors (S)-10a, (R)-10a, and 10b were binding within the MMP-13 active site, the Zn 2+ chelating unit was replaced with nonchelating polar residues that bridged over the Zn 2+ binding site and reached into a solvent accessible area. After two rounds of structural optimization, these design approaches led to small molecule MMP-13 inhibitors 10d and (S)-17b, which bind within the substrate-binding site of MMP-13 and surround the catalytically active Zn 2+ ion without chelating to the metal. These compounds exhibit at least 500-fold selectivity versus other MMPs.

Cell-Cell Transmission Enables HIV-1 to Evade Inhibition by Potent CD4bs Directed Antibodies

PubMed Central

Schanz, Merle; Reynell, Lucy; Günthard, Huldrych F.; Rusert, Peter; Trkola, Alexandra

2012-01-01

HIV is known to spread efficiently both in a cell-free state and from cell to cell, however the relative importance of the cell-cell transmission mode in natural infection has not yet been resolved. Likewise to what extent cell-cell transmission is vulnerable to inhibition by neutralizing antibodies and entry inhibitors remains to be determined. Here we report on neutralizing antibody activity during cell-cell transmission using specifically tailored experimental strategies which enable unambiguous discrimination between the two transmission routes. We demonstrate that the activity of neutralizing monoclonal antibodies (mAbs) and entry inhibitors during cell-cell transmission varies depending on their mode of action. While gp41 directed agents remain active, CD4 binding site (CD4bs) directed inhibitors, including the potent neutralizing mAb VRC01, dramatically lose potency during cell-cell transmission. This implies that CD4bs mAbs act preferentially through blocking free virus transmission, while still allowing HIV to spread through cell-cell contacts. Thus providing a plausible explanation for how HIV maintains infectivity and rapidly escapes potent and broadly active CD4bs directed antibody responses in vivo. PMID:22496655

Pre-clinical pharmacology of ICI D2138, a potent orally-active non-redox inhibitor of 5-lipoxygenase.

PubMed Central

McMillan, R. M.; Spruce, K. E.; Crawley, G. C.; Walker, E. R.; Foster, S. J.

1992-01-01

1. This paper describes the pre-clinical pharmacology of ICI D2138, a potent orally-active non-redox inhibitor of 5-lipoxygenase which is undergoing clinical evaluation. 2. ICI D2138 potently inhibited leukotriene synthesis in murine peritoneal macrophages (IC50 = 3 nM) and human blood (IC50 = 20 nM). In human and dog blood, ICI D2138 did not inhibit thromboxane B2 synthesis at a concentration of 500 microM, thus the selectivity ratio (cyclo-oxygenase: 5-lipoxygenase) was greater than 20,000. In contrast, zileuton (a 5-lipoxygenase inhibitor also undergoing clinical evaluation) exhibited a selectivity ratio of 15-100. 3. ICI D2138 potently and dose-dependently inhibited ex vivo leukotriene B4 (LTB4) synthesis by rat blood with ED50 values of 0.9, 4.0 and 80.0 mg kg-1 p.o. at 3, 10 and 20 h respectively after dosing. Similar activity was observed for inhibition of LTB4 production in a zymosan-inflamed rat air pouch model. Zileuton produced ED50 values of 5 and 20 mg kg-1 at 3 and 10 h respectively. 4. Oral administration of 1, 3 or 10 mg kg-1 ICI D2138 to dogs produced maximal inhibition of ex vivo LTB4 synthesis by blood for 5, 9 and 31 h respectively. A dose of 5 mg kg-1 p.o. of zileuton caused maximal inhibition of LTB4 for 24 h. 5. Oral administration of 10 mg kg-1 ICI D2138 caused total inhibition of LTB4 production in zymosan-inflamed rabbit knee joint. 6. Topical administration of ICI D2138 to rabbit skin caused a dose-related inhibition of arachidonic acid-induced plasma extravasation with an ID30 of 1.08 nmol per site.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1334748

Tetrahydrocannabinolic acid is a potent PPARγ agonist with neuroprotective activity.

PubMed

Nadal, Xavier; Del Río, Carmen; Casano, Salvatore; Palomares, Belén; Ferreiro-Vera, Carlos; Navarrete, Carmen; Sánchez-Carnerero, Carolina; Cantarero, Irene; Bellido, Maria Luz; Meyer, Stefan; Morello, Gaetano; Appendino, Giovanni; Muñoz, Eduardo

2017-12-01

Phytocannabinoids are produced in Cannabis sativa L. in acidic form and are decarboxylated upon heating, processing and storage. While the biological effects of decarboxylated cannabinoids such as Δ 9 -tetrahydrocannabinol have been extensively investigated, the bioactivity of Δ 9 -tetahydrocannabinol acid (Δ 9 -THCA) is largely unknown, despite its occurrence in different Cannabis preparations. Here we have assessed possible neuroprotective actions of Δ 9 -THCA through modulation of PPARγ pathways. The effects of six phytocannabinoids on PPARγ binding and transcriptional activity were investigated. The effect of Δ 9 -THCA on mitochondrial biogenesis and PPARγ coactivator 1-α expression was investigated in Neuro-2a (N2a) cells. The neuroprotective effect was analysed in STHdh Q111/Q111 cells expressing a mutated form of the huntingtin protein and in N2a cells infected with an adenovirus carrying human huntingtin containing 94 polyQ repeats (mHtt-q94). The in vivo neuroprotective activity of Δ 9 -THCA was investigated in mice intoxicated with the mitochondrial toxin 3-nitropropionic acid (3-NPA). Cannabinoid acids bind and activate PPARγ with higher potency than their decarboxylated products. Δ 9 -THCA increased mitochondrial mass in neuroblastoma N2a cells and prevented cytotoxicity induced by serum deprivation in STHdh Q111/Q111 cells and by mutHtt-q94 in N2a cells. Δ 9 -THCA, through a PPARγ-dependent pathway, was neuroprotective in mice treated with 3-NPA, improving motor deficits and preventing striatal degeneration. In addition, Δ 9 -THCA attenuated microgliosis, astrogliosis and up-regulation of proinflammatory markers induced by 3-NPA. Δ 9 -THCA shows potent neuroprotective activity, which is worth considering for the treatment of Huntington's disease and possibly other neurodegenerative and neuroinflammatory diseases. © 2017 The British Pharmacological Society.

Catechins and procyanidins of Ginkgo biloba show potent activities towards the inhibition of β-amyloid peptide aggregation and destabilization of preformed fibrils.

PubMed

Xie, Haiyan; Wang, Jing-Rong; Yau, Lee-Fong; Liu, Yong; Liu, Liang; Han, Quan-Bin; Zhao, Zhongzhen; Jiang, Zhi-Hong

2014-04-22

Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761). In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds, six of them were identified as (+)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin and procyanidins B1 and B3. The activities of these polyphenols in the inhibition of Aβ42 aggregation and the destabilization of preformed fibrils were evaluated using biochemical assays, which showed that all six of the polyphenols, as well as a fraction of the extract of Ginkgo biloba leaves (EGb) containing catechins and procyanidins, exerted potent inhibitory activities towards Aβ42 aggregation and could also destabilize the performed fibrils. Catechins and procyanidins can therefore be regarded as the potent active constituents of EGb761 in terms of their inhibition of Aβ42 aggregation and destabilization of the fibrils. Although quantitative mass spectroscopic analysis revealed that the catechins and procyanidins are only present in low concentrations in EGb761, these components should be studied in greater detail because of their potent inhibitory effects towards Aβ42 aggregation and their ability to destabilize preformed fibrils, especially during the quality control of Ginkgo leaves and the manufacture of Ginkgo products.

Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity

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

Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn

Highlights: • Screening of 50,000 compounds and subsequent lead optimization identified WV970. • WV970 has antiviral effects against influenza A, B and highly pathogenic viral strains. • WV970 inhibits viral genome replication and transcription. • A target database search suggests that WV970 may bind to a number of kinases. • KINOMEscan screening revealed that WV970 has inhibitory effects on 15 kinases. - Abstract: Neuraminidase inhibitors are the only currently available influenza treatment, although resistant viruses to these drugs have already been reported. Thus, new antiviral drugs with novel mechanisms of action are urgently required. In this study, we identified amore » novel antiviral compound, WV970, through cell-based screening of a 50,000 compound library and subsequent lead optimization. This compound exhibited potent antiviral activity with nanomolar IC{sub 50} values against both influenza A and B viruses but not non-influenza RNA viruses. Time-of-addition and indirect immunofluorescence assays indicated that WV970 acted at an early stage of the influenza life cycle, but likely after nuclear entry of viral ribonucleoprotein (vRNP). Further analyses of viral RNA expression and viral polymerase activity indicated that WV970 inhibited vRNP-mediated viral genome replication and transcription. Finally, structure-based virtual screening and comprehensive human kinome screening were used to demonstrate that WV970 acts as a multiple kinase inhibitor, many of which are associated with influenza virus replication. Collectively, these results strongly suggest that WV970 is a promising anti-influenza drug candidate and that several kinases associated with viral replication are promising drug targets.« less

Indolyl Azaspiroketal Mannich Bases Are Potent Antimycobacterial Agents with Selective Membrane Permeabilizing Effects and in Vivo Activity.

PubMed

Nyantakyi, Samuel Agyei; Li, Ming; Gopal, Pooja; Zimmerman, Matthew; Dartois, Véronique; Gengenbacher, Martin; Dick, Thomas; Go, Mei-Lin

2018-06-25

The inclusion of an azaspiroketal Mannich base in the membrane targeting antitubercular 6-methoxy-1- n-octyl-1 H-indole scaffold resulted in analogs with improved selectivity and submicromolar activity against Mycobacterium tuberculosis H37Rv. The potency enhancing properties of the spiro-fused ring motif was affirmed by SAR and validated in a mouse model of tuberculosis. As expected for membrane inserting agents, the indolyl azaspiroketal Mannich bases perturbed phospholipid vesicles, permeabilized bacterial cells, and induced the mycobacterial cell envelope stress reporter promoter p iniBAC. Surprisingly, their membrane disruptive effects did not appear to be associated with bacterial membrane depolarization. This profile was not uniquely associated with azaspiroketal Mannich bases but was characteristic of indolyl Mannich bases as a class. Whereas resistant mycobacteria could not be isolated for a less potent indolyl Mannich base, the more potent azaspiroketal analog displayed low spontaneous resistance mutation frequency of 10 -8 /CFU. This may indicate involvement of an additional envelope-related target in its mechanism of action.

Structure-Based Design of Potent Bcl-2/Bcl-xL Inhibitors with Strong in Vivo Antitumor Activity

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

Zhou, Haibin; Aguilar, Angelo; Chen, Jianfang

Bcl-2 and Bcl-xL are key apoptosis regulators and attractive cancer therapeutic targets. We have designed and optimized a class of small-molecule inhibitors of Bcl-2 and Bcl-xL containing a 4,5-diphenyl-1H-pyrrole-3-carboxylic acid core structure. A 1.4 {angstrom} resolution crystal structure of a lead compound, 12, complexed with Bcl-xL has provided a basis for our optimization. The most potent compounds, 14 and 15, bind to Bcl-2 and Bcl-xL with subnanomolar K{sub i} values and are potent antagonists of Bcl-2 and Bcl-xL in functional assays. Compounds 14 and 15 inhibit cell growth with low nanomolar IC{sub 50} values in multiple small-cell lung cancer cellmore » lines and induce robust apoptosis in cancer cells at concentrations as low as 10 nM. Compound 14 also achieves strong antitumor activity in an animal model of human cancer.« less

Synthesis, biological evaluation and structure-activity relationship studies of isoflavene based Mannich bases with potent anti-cancer activity.

PubMed

Chen, Yilin; Cass, Shelley L; Kutty, Samuel K; Yee, Eugene M H; Chan, Daniel S H; Gardner, Christopher R; Vittorio, Orazio; Pasquier, Eddy; Black, David StC; Kumar, Naresh

2015-11-15

Phenoxodiol, an analogue of the isoflavone natural product daidzein, is a potent anti-cancer agent that has been investigated for the treatment of hormone dependent cancers. This molecular scaffold was reacted with different primary amines and secondary amines under different Mannich conditions to yield either benzoxazine or aminomethyl substituted analogues. These processes enabled the generation of a diverse range of analogues that were required for structure-activity relationship (SAR) studies. The resulting Mannich bases exhibited prominent anti-proliferative effects against SHEP neuroblastoma and MDA-MB-231 breast adenocarcinoma cell lines. Further cytotoxicity studies against MRC-5 normal lung fibroblast cells showed that the isoflavene analogues were selective towards cancer cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Compound of Mangiferin-Berberine Salt Has Potent Activities in Modulating Lipid and Glucose Metabolisms in HepG2 Cells

PubMed Central

Wang, Can; Jiang, Jian-Dong; Wu, Wei; Kong, Wei-Jia

2016-01-01

The mangiferin-berberine (MB) salt was synthesized by ionic bonding of mangiferin (M) and berberine (B) at an equal molecular ratio. This study aimed to investigate the activities of MB salt in modulating lipid and glucose metabolisms in HepG2 cells. After 24 h treatment of the studying compounds, cellular AMP-activated protein kinase α (AMPKα)/acetyl-CoA carboxylase (ACC) protein levels and carnitine palmitoyltransferase (CPT) 1 activities, intracellular lipid contents, mRNA expression levels of target genes, glucose consumption, and glucose production amounts were determined. Compound C (CC) was used in the blocking experiments. Our results showed that MB salt increased p-AMPKα (Thr172)/p-ACC (Ser79) levels and CPT1 activity and suppressed oleic acid- (OA-) induced lipid accumulation and upregulation of lipogenic genes potently in HepG2 cells. The above activities of MB salt were AMPK dependent and were superior to those of M or B when administered at an equal molar concentration. MB salt enhanced basal and insulin-stimulated glucose consumption and suppressed gluconeogenesis more potently than M or B alone. The inhibiting activity of MB salt on cellular gluconeogenesis was AMPK dependent. Our results may support MB salt as a new kind of agent for the development of novel lipid or glucose-lowering drugs in the future. PMID:27123455

10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

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

Goto, Tsuyoshi, E-mail: tgoto@kais.kyoto-u.ac.jp; Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University; Kim, Young-Il

2015-04-17

Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increasedmore » adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis.« less

Potent HGF/c-Met axis inhibitors from Eucalyptus globulus: the coupling of phloroglucinol and sesquiterpenoid is essential for the activity.

PubMed

Yang, Sheng-Ping; Zhang, Xiao-Wei; Ai, Jing; Gan, Li-She; Xu, Jin-Biao; Wang, Ying; Su, Zu-Shang; Wang, Lu; Ding, Jian; Geng, Mei-Yu; Yue, Jian-Min

2012-09-27

Eucalyptin A (1), together with two known compounds 2 and 3 exhibiting potent inhibition on HGF/c-Met axis, was discovered from the fruits of Eucalyptus globulus. 1 possessed an unprecedented carbon framework of phloroglucinol-coupled sesquiterpenoid, and its structure was elucidated by spectroscopic method and ECD calculation. A brief structure-activity relationship discussion indicated that the coupling of a phloroglucinol and a sesquiterpenoid is essential for the activity.

Discovery of Aryl Aminoquinazoline Pyridones as Potent, Selective, and Orally Efficacious Inhibitors of Receptor Tyrosine Kinase c-Kit

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

Hu, Essa; Tasker, Andrew; White, Ryan D.

2008-12-09

Inhibition of c-Kit has the potential to treat mast cell associated fibrotic diseases. We report the discovery of several aminoquinazoline pyridones that are potent inhibitors of c-Kit with greater than 200-fold selectivity against KDR, p38, Lck, and Src. In vivo efficacy of pyridone 16 by dose-dependent inhibition of histamine release was demonstrated in a rodent pharmacodynamic model of mast cell activation.

Potent, nonsteroidal selective androgen receptor modulators (SARMs) based on 8H-[1,4]oxazino[2,3-f]quinolin-8-ones.

PubMed

Higuchi, Robert I; Thompson, Anthony W; Chen, Jyun-Hung; Caferro, Thomas R; Cummings, Marquis L; Deckhut, Charlotte P; Adams, Mark E; Tegley, Christopher M; Edwards, James P; López, Francisco J; Kallel, E Adam; Karanewsky, Donald S; Schrader, William T; Marschke, Keith B; Zhi, Lin

2007-10-01

A series of androgen receptor modulators based on 8H-[1,4]oxazino[2,3-f]quinolin-8-ones was synthesized and evaluated in an androgen receptor transcriptional activation assay. The most potent analogues from the series exhibited single-digit nanomolar potency in vitro. Compound 18h demonstrated full efficacy in the maintenance of muscle weight, at 10 mg/kg, with reduced activity in prostate weight in an in vivo model of androgen action.

Discovery of novel alkylated (bis)urea and (bis)thiourea polyamine analogues with potent antimalarial activities.

PubMed

Verlinden, Bianca K; Niemand, Jandeli; Snyman, Janette; Sharma, Shiv K; Beattie, Ross J; Woster, Patrick M; Birkholtz, Lyn-Marie

2011-10-13

A series of alkylated (bis)urea and (bis)thiourea polyamine analogues were synthesized and screened for antimalarial activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum in vitro. All analogues showed growth inhibitory activity against P. falciparum at less than 3 μM, with the majority having effective IC(50) values in the 100-650 nM range. Analogues arrested parasitic growth within 24 h of exposure due to a block in nuclear division and therefore asexual development. Moreover, this effect appears to be cytotoxic and highly selective to malaria parasites (>7000-fold lower IC(50) against P. falciparum) and is not reversible by the exogenous addition of polyamines. With this first report of potent antimalarial activity of polyamine analogues containing 3-7-3 or 3-6-3 carbon backbones and substituted terminal urea- or thiourea moieties, we propose that these compounds represent a structurally novel class of antimalarial agents.

Potent NLRP3 Inflammasome Activation by the HIV Reverse Transcriptase Inhibitor Abacavir.

PubMed

Toksoy, Atiye; Sennefelder, Helga; Adam, Christian; Hofmann, Sonja; Trautmann, Axel; Goebeler, Matthias; Schmidt, Marc

2017-02-17

There is experimental and clinical evidence that some exanthematous allergic drug hypersensitivity reactions are mediated by drug-specific T cells. We hypothesized that the capacity of certain drugs to directly stimulate the innate immune system may contribute to generate drug-specific T cells. Here we analyzed whether abacavir, an HIV-1 reverse transcriptase inhibitor often inducing severe delayed-type drug hypersensitivity, can trigger innate immune activation that may contribute to its allergic potential. We show that abacavir fails to generate direct innate immune activation in human monocytes but potently triggers IL-1β release upon pro-inflammatory priming with phorbol ester or Toll-like receptor stimulation. IL-1β processing and secretion were sensitive to Caspase-1 inhibition, NLRP3 knockdown, and K + efflux inhibition and were not observed with other non-allergenic nucleoside reverse transcriptase inhibitors, identifying abacavir as a specific inflammasome activator. It further correlated with dose-dependent mitochondrial reactive oxygen species production and cytotoxicity, indicating that inflammasome activation resulted from mitochondrial damage. However, both NLRP3 depletion and inhibition of K + efflux mitigated abacavir-induced mitochondrial reactive oxygen species production and cytotoxicity, suggesting that these processes were secondary to NLRP3 activation. Instead, depletion of cardiolipin synthase 1 abolished abacavir-induced IL-1β secretion, suggesting that mitochondrial cardiolipin release may trigger abacavir-induced inflammasome activation. Our data identify abacavir as a novel inflammasome-stimulating drug allergen. They implicate a potential contribution of innate immune activation to medication-induced delayed-type hypersensitivity, which may stimulate new concepts for treatment and prevention of drug allergies. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Triterpene esters from Uncaria rhynchophylla drive potent IL-12-dependent Th1 polarization.

PubMed

Umeyama, Akemi; Yahisa, Yoshinori; Okada, Minori; Okayama, Eriko; Uda, Ayaka; Shoji, Noboru; Lee, Je-Jung; Takei, Masao; Hashimoto, Toshihiro

2010-10-01

Dendritic cells (DC) are key antigen-presenting cells that link innate and adaptive immunity and ultimately activate antigen-specific T cells. In the current study, we demonstrated that two triterpene esters, uncarinic acid C (1) and uncarinic acid D (2), which are isolated from the hooks of Uncaria rhynchophylla, activate phenotypic and cytokine production alterations in DC. We also show that 1 and 2 modulate human DC function in a fashion that favors Th1 cell polarization. The effect of 1 (E configuration at the 2' position) was approximately 20 times more potent than that of 2 (Z configuration at 2'). These results indicated that the configuration of the 2' double bond greatly effects activity. Thus, 1 and 2 may prove useful as DC-based vaccines for cancer immunotherapy.

Pityriazepin and other potent AhR ligands isolated from Malassezia furfur yeast

PubMed Central

Mexia, Nikitia; Gaitanis, George; Velegraki, Aristea; Soshilov, Anatoly; Denison, Michael S.; Magiatis, Prokopios

2015-01-01

Malassezia furfur yeast strains isolated from diseased human skin preferentially biosynthesize indole alkaloids which can be detected in human skin and are highly potent activators of the aryl hydrocarbon receptor (AhR) and AhR-dependent gene expression. Chemical analysis of an EtOAc extract of a M. furfur strain obtained from diseased human skin and grown on L-tryptophan agar revealed several known AhR active tryptophan metabolites along with a previously unidentified compound, pityriazepin. While its structure resembled that of the known alkaloid pityriacitrin, the comprised pyridine ring had been transformed into an azepinone. The indoloazepinone scaffold of pityriazepin is extremely rare in nature and has only been reported once previously. Pityriazepin, like the other isolated compounds, was found to be a potent activator of the AhR-dependent reporter gene assays in recombinant cell lines derived from four different species, although significant species differences in relative potency was observed. The ability of pityriazepin to competitively bind to the AhR and directly stimulate AhR DNA binding classified it as a new naturally-occurring potent AhR agonist. Malassezia furfur produces an expanded collection of extremely potent naturally occurring AhR agonists, which produce their biological effects in a species-specific manner.1 PMID:25721496

The pharmacology of TUG-891, a potent and selective agonist of the free fatty acid receptor 4 (FFA4/GPR120), demonstrates both potential opportunity and possible challenges to therapeutic agonism.

PubMed

Hudson, Brian D; Shimpukade, Bharat; Mackenzie, Amanda E; Butcher, Adrian J; Pediani, John D; Christiansen, Elisabeth; Heathcote, Helen; Tobin, Andrew B; Ulven, Trond; Milligan, Graeme

2013-11-01

TUG-891 [3-(4-((4-fluoro-4'-methyl-[1,1'-biphenyl]-2-yl)methoxy)phenyl)propanoic acid] was recently described as a potent and selective agonist for the long chain free fatty acid (LCFA) receptor 4 (FFA4; previously G protein-coupled receptor 120, or GPR120). Herein, we have used TUG-891 to further define the function of FFA4 and used this compound in proof of principle studies to indicate the therapeutic potential of this receptor. TUG-891 displayed similar signaling properties to the LCFA α-linolenic acid at human FFA4 across various assay end points, including stimulation of Ca²⁺ mobilization, β-arrestin-1 and β-arrestin-2 recruitment, and extracellular signal-regulated kinase phosphorylation. Activation of human FFA4 by TUG-891 also resulted in rapid phosphorylation and internalization of the receptor. While these latter events were associated with desensitization of the FFA4 signaling response, removal of TUG-891 allowed both rapid recycling of FFA4 back to the cell surface and resensitization of the FFA4 Ca²⁺ signaling response. TUG-891 was also a potent agonist of mouse FFA4, but it showed only limited selectivity over mouse FFA1, complicating its use in vivo in this species. Pharmacologic dissection of responses to TUG-891 in model murine cell systems indicated that activation of FFA4 was able to mimic many potentially beneficial therapeutic properties previously reported for LCFAs, including stimulating glucagon-like peptide-1 secretion from enteroendocrine cells, enhancing glucose uptake in 3T3-L1 adipocytes, and inhibiting release of proinflammatory mediators from RAW264.7 macrophages, which suggests promise for FFA4 as a therapeutic target for type 2 diabetes and obesity. Together, these results demonstrate both potential but also significant challenges that still need to be overcome to therapeutically target FFA4.

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

PubMed

Matralis, Alexios N; Kourounakis, Angeliki P

2014-03-27

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

Discovery of DF-461, a Potent Squalene Synthase Inhibitor

PubMed Central

2013-01-01

We report the development of a new trifluoromethyltriazolobenzoxazepine series of squalene synthase inhibitors. Structure–activity studies and pharmacokinetics optimization on this series led to the identification of compound 23 (DF-461), which exhibited potent squalene synthase inhibitory activity, high hepatic selectivity, excellent rat hepatic cholesterol synthesis inhibitory activity, and plasma lipid lowering efficacy in nonrodent repeated dose studies. PMID:24900587

Inhibition of HDACs-EphA2 Signaling Axis with WW437 Demonstrates Promising Preclinical Antitumor Activity in Breast Cancer.

PubMed

Zhang, Tao; Li, Jingjie; Ma, Xiaojun; Yang, Yang; Sun, Wei; Jin, Wangrui; Wang, Lei; He, Yuan; Yang, Feifei; Yi, Zhengfang; Hua, Yingqi; Liu, Mingyao; Chen, Yihua; Cai, Zhengdong

2018-05-01

Histone deacetylase inhibitors (HDACi) are small molecules targeting epigenetic enzymes approved for hematologic neoplasms, which have also demonstrated clinical activities in solid tumors. In our present study, we screened our internal compound library and discovered a novel HDACi, WW437, with potent anti-breast cancer ability in vitro and in vivo. WW437 significantly inhibited phosphorylated EphA2 and EphA2 expression. Further study demonstrated WW437 blocked HDACs-EphA2 signaling axis in breast cancer. In parallel, we found that EphA2 expression positively correlates with breast cancer progression; and combined use of WW437 and an EphA2 inhibitor (ALW-II-41-27) exerted more remarkable effect on breast cancer growth than either drug alone. Our findings suggested inhibition of HDACs-EphA2 signaling axis with WW437 alone or in combination with other agents may be a promising therapeutic strategy for advanced breast cancer. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Caged Garcinia Xanthones, a Novel Chemical Scaffold with Potent Antimalarial Activity.

PubMed

Ke, Hangjun; Morrisey, Joanne M; Qu, Shiwei; Chantarasriwong, Oraphin; Mather, Michael W; Theodorakis, Emmanuel A; Vaidya, Akhil B

2017-01-01

Caged Garcinia xanthones (CGXs) constitute a family of natural products that are produced by tropical/subtropical trees of the genus Garcinia CGXs have a unique chemical architecture, defined by the presence of a caged scaffold at the C ring of a xanthone moiety, and exhibit a broad range of biological activities. Here we show that synthetic CGXs exhibit antimalarial activity against Plasmodium falciparum, the causative parasite of human malaria, at the intraerythrocytic stages. Their activity can be substantially improved by attaching a triphenylphosphonium group at the A ring of the caged xanthone. Specifically, CR135 and CR142 were found to be highly effective antimalarial inhibitors, with 50% effective concentrations as low as ∼10 nM. CGXs affect malaria parasites at multiple intraerythrocytic stages, with mature stages (trophozoites and schizonts) being more vulnerable than immature rings. Within hours of CGX treatment, malaria parasites display distinct morphological changes, significant reduction of parasitemia (the percentage of infected red blood cells), and aberrant mitochondrial fragmentation. CGXs do not, however, target the mitochondrial electron transport chain, the target of the drug atovaquone and several preclinical candidates. CGXs are cytotoxic to human HEK293 cells at the low micromolar level, which results in a therapeutic window of around 150-fold for the lead compounds. In summary, we show that CGXs are potent antimalarial compounds with structures distinct from those of previously reported antimalarial inhibitors. Our results highlight the potential to further develop Garcinia natural product derivatives as novel antimalarial agents. Copyright © 2016 American Society for Microbiology.

1-[(3-Aryloxy-3-aryl)propyl]-1H-imidazoles, new imidazoles with potent activity against Candida albicans and dermatophytes. Synthesis, structure-activity relationship, and molecular modeling studies.

PubMed

La Regina, Giuseppe; D'Auria, Felicia Diodata; Tafi, Andrea; Piscitelli, Francesco; Olla, Stefania; Caporuscio, Fabiana; Nencioni, Lucia; Cirilli, Roberto; La Torre, Francesco; De Melo, Nadja Rodrigues; Kelly, Steven L; Lamb, David C; Artico, Marino; Botta, Maurizio; Palamara, Anna Teresa; Silvestri, Romano

2008-07-10

New 1-[(3-aryloxy-3-aryl)propyl]-1 H-imidazoles were synthesized and evaluated against Candida albicans and dermatophytes in order to develop structure-activity relationships (SARs). Against C. albicans the new imidazoles showed minimal inhibitory concentrations (MICs) comparable to those of ketoconazole, miconazole, and econazole, and were more potent than fluconazole. Several derivatives ( 10, 12, 14, 18- 20, 24, 28, 29, 30, and 34) turned out to be potent inhibitors of C. albicans strains resistant to fluconazole, with MIC values less than 10 microg/mL. Against dermatophytes strains, compounds 20, 25, and 33 (MIC

The Analgesic Activity of Bestatin as a Potent APN Inhibitor

PubMed Central

Jia, Mei-Rong; Wei, Tao; Xu, Wen-Fang

2010-01-01

Bestatin, a small molecular weight dipeptide, is a potent inhibitor of various aminopeptidases as well as LTA4 hydrolase. Various physiological functions of Bestatin have been identified, viz.: (1) an immunomodifier for enhancing the proliferation of normal human bone marrow granulocyte–macrophage progenitor cells to form CFU-GM colonies; Bestatin exerts a direct stimulating effect on lymphocytes via its fixation on the cell surface and an indirect effect on monocytes via aminopeptidase B inhibition of tuftsin catabolism; (2) an immunorestorator and curative or preventive agent for spontaneous tumor; Bestatin alone or its combination with chemicals can prolongate the disease-free interval and survival period in adult acute or chronic leukemia, therefore, it was primarily marketed in 1987 in Japan as an anticancer drug and servers as the only marketed inhibitor of Aminopeptidase N (APN/CD13) to cure leukemia to date; (3) a pan-hematopoietic stimulator and restorator; Bestatin promotes granulocytopoiesis and thrombocytopoiesis in vitro and restores them in myelo-hypoplastic men; (4) an inhibitor of several natural opioid peptides. Based on the knowledge that APN can cleave several bioactive neuropeptides such as Met-enkaphalins, Leu-enkaphalins, β-Endorphin, and so on, the anti-aminopeptidase action of Bestatin also allows it to protect endopeptides against their catabolism, exhibiting analgesic activity. Although many scientific studies and great accomplishments have been achieved in this field, a large amount of problems are unsolved. This article reviews the promising results obtained for future development of the analgesic activity of Bestatin that can be of vital interest in a number of severe and chronic pain syndromes. PMID:20631848

Concise Synthesis and Biological Evaluation of 2-Aroyl-5-Amino Benzo[b]thiophene Derivatives As a Novel Class of Potent Antimitotic Agents

PubMed Central

Romagnoli, Romeo; Baraldi, Pier Giovanni; Lopez-Cara, Carlota; Preti, Delia; Tabrizi, Mojgan Aghazadeh; Balzarini, Jan; Bassetto, Marcella; Brancale, Andrea; Fu, Xian-Hua; Gao, Yang; Li, Jun; Zhang, Su-Zhan; Hamel, Ernest; Bortolozzi, Roberta; Basso, Giuseppe; Viola, Giampietro

2014-01-01

The biological importance of microtubules make them an interesting target for the synthesis of antitumor agents. The 2-(3′,4′,5′-trimethoxybenzoyl)-5-aminobenzo[b]thiophene moiety was identified as a novel scaffold for the preparation of potent inhibitors of microtubule polymerization acting through the colchicine site of tubulin. The position of the methoxy group on the benzo[b]thiophene was important for maximal antiproliferative activity. Structure–activity relationship analysis established that the best activities were obtained with amino and methoxy groups placed at the C-5 and C-7 positions, respectively. Compounds 3c–e showed more potent inhibition of tubulin polymerization than combretastatin A-4 and strong binding to the colchicine site. These compounds also demonstrated substantial antiproliferative activity, with IC50 values ranging from 2.6 to 18 nM in a variety of cancer cell lines. Importantly, compound 3c (50 mg/kg), significantly inhibited the growth of the human osteosarcoma MNNG/HOS xenograft in nude mice. PMID:24164557

Development of potent ALK inhibitor and its molecular inhibitory mechanism against NSCLC harboring EML4-ALK proteins.

PubMed

Kang, Chung Hyo; Yun, Jeong In; Lee, Kwangho; Lee, Chong Ock; Lee, Heung Kyoung; Yun, Chang-Soo; Hwang, Jong Yeon; Cho, Sung Yun; Jung, Heejung; Kim, Pilho; Ha, Jae Du; Jeon, Jeong Hee; Choi, Sang Un; Jeong, Hye Gwang; Kim, Hyoung Rae; Park, Chi Hoon

2015-08-28

Here, we show the newly synthesized and potent ALK inhibitor having similar scaffold to KRCA-0008, which was reported previously, and its molecular mechanism against cancer cells harboring EML4-ALK fusion protein. Through ALK wild type enzyme assay, we selected two compounds, KRCA-0080 and KRCA-0087, which have trifluoromethyl instead of chloride in R2 position. We characterized these newly synthesized compounds by in vitro and in vivo assays. Enzyme assay shows that KRCA-0080 is more potent against various ALK mutants, including L1196M, G1202R, T1151_L1152insT, and C1156Y, which are seen in crizotinib-resistant patients, than KRCA-0008 is. Cell based assays demonstrate our compounds downregulate the cellular signaling, such as Akt and Erk, by suppressing ALK activity to inhibit the proliferation of the cells harboring EML4-ALK. Interestingly, our compounds induced strong G1/S arrest in H3122 cells leading to the apoptosis, which is proved by PARP-1 cleavage. In vivo H3122 xenograft assay, we found that KRCA-0080 shows significant reduction in tumor size compared to crizotinib and KRCA-0008 by 15-20%. Conclusively, we report a potent ALK inhibitor which shows significant in vivo efficacy as well as excellent inhibitory activity against various ALK mutants. Copyright © 2015 Elsevier Inc. All rights reserved.

Orally available stilbene derivatives as potent HDAC inhibitors with antiproliferative activities and antitumor effects in human tumor xenografts.

PubMed

Kachhadia, Virendra; Rajagopal, Sridharan; Ponpandian, Thanasekaran; Vignesh, Radhakrishnan; Anandhan, Karnambaram; Prabhu, Daivasigamani; Rajendran, Praveen; Nidhyanandan, Saranya; Roy, Anshu Mittal; Ahamed, Fakrudeen Ali; Surendran, Narayanan; Rajagopal, Sriram; Narayanan, Shridhar; Gopalan, Balasubramanian

2016-01-27

Herein we report the synthesis and activity of a novel class of HDAC inhibitors based on 2, 3-diphenyl acrylic acid derivatives. The compounds in this series have shown to be potent HDAC inhibitors possessing significant antiproliferative activity. Further compounds in this series were subjected to metabolic stability in human liver microsomes (HLM), mouse liver microsomes (MLM), and exhibits promising stability in both. These efforts culminated with the identification of a developmental candidate (5a), which displayed desirable PK/PD relationships, significant efficacy in the xenograft models and attractive ADME profiles. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Potent anti-cervical cancer activity: synergistic effects of Thai medicinal plants in recipe N040 selected from the MANOSROI III database.

PubMed

Kitdamrongtham, Worapong; Manosroi, Aranya; Akazawa, Hiroyuki; Gidado, Abubakar; Stienrut, Pramote; Manosroi, Worapaka; Lohcharoenkal, Warangkana; Akihisa, Toshihiro; Manosroi, Jiradej

2013-08-26

its methanolic extract and ascorbic acid, respectively. Poor metal chelating activity (MC50>500 µg/ml) was observed in methanolic extract and all fractions. The highest phenolic and flavonoid contents were observed in the methanolic extract. Brazilin, the known compound isolated from the EtOAc fraction exhibited potent anti-proliferative activity with the IC50 of 0.28 µg/ml which was higher than its methanolic extract and EtOAc fraction of 119.50 and 63.61 folds, respectively, but only 0.39 fold of the recipe extract N040. The tumor size of the HeLa cell xenograft nude mice treated with the recipe N040 at the dose of 44.50mg/kg body weight per day was significantly smaller (p<0.05) than that of the control with the relative tumor weight inhibition of 57.23% which was 0.65 fold of cisplatin. In the subchronic toxicity study, N040 given orally at the dose of 1000 mg/kg body weight per day for 90 days showed no alteration in body weight gain, hematology [except the increase mean corpuscular hemoglobin (MCH) in the treated male rats] and clinical blood chemistry (except the increase blood glucose in the treated male rats) both in female and male rats. Only minor lesions of the organs including lung, liver, kidney and small intestine were observed in both sexes. This study has demonstrated the synergistic effect of the plants composed in the recipe which resulted in the potent anti-cancer activity and confirmed the traditionally use of the recipe N040. In addition, this study has also suggested the compound brazilin isolated from Caesalpinia sappan for its high potential to be further investigated as a novel anti-cervical cancer drug. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Imidazopyridine derivatives as potent and selective Polo-like kinase (PLK) inhibitors.

PubMed

Sato, Yoshiyuki; Onozaki, Yu; Sugimoto, Tetsuya; Kurihara, Hideki; Kamijo, Kaori; Kadowaki, Chie; Tsujino, Toshiaki; Watanabe, Akiko; Otsuki, Sachie; Mitsuya, Morihiro; Iida, Masato; Haze, Kyosuke; Machida, Takumitsu; Nakatsuru, Yoko; Komatani, Hideya; Kotani, Hidehito; Iwasawa, Yoshikazu

2009-08-15

A novel class of imidazopyridine derivatives was designed as PLK1 inhibitors. Extensive SAR studies supported by molecular modeling afforded a highly potent and selective compound 36. Compound 36 demonstrated good antitumor efficacy in xenograft nude rat model.

Prime-Boost Immunization of Rabbits with HIV-1 gp120 Elicits Potent Neutralization Activity against a Primary Viral Isolate

PubMed Central

Narayan, Kristin M.; Agrawal, Nitish; Du, Sean X.; Muranaka, Janelle E.; Bauer, Katherine; Leaman, Daniel P.; Phung, Pham; Limoli, Kay; Chen, Helen; Boenig, Rebecca I.; Wrin, Terri; Zwick, Michael B.; Whalen, Robert G.

2013-01-01

Development of a vaccine for HIV-1 requires a detailed understanding of the neutralizing antibody responses that can be experimentally elicited to difficult-to-neutralize primary isolates. Rabbits were immunized with the gp120 subunit of HIV-1 JR-CSF envelope (Env) using a DNA-prime protein-boost regimen. We analyzed five sera that showed potent autologous neutralizing activity (IC50s at ∼103 to 104 serum dilution) against pseudoviruses containing Env from the primary isolate JR-CSF but not from the related isolate JR-FL. Pseudoviruses were created by exchanging each variable and constant domain of JR-CSF gp120 with that of JR-FL or with mutations in putative N-glycosylation sites. The sera contained different neutralizing activities dependent on C3 and V5, C3 and V4, or V4 regions located on the glycan-rich outer domain of gp120. All sera showed enhanced neutralizing activity toward an Env variant that lacked a glycosylation site in V4. The JR-CSF gp120 epitopes recognized by the sera are generally distinct from those of several well characterized mAbs (targeting conserved sites on Env) or other type-specific responses (targeting V1, V2, or V3 variable regions). The activity of one serum requires specific glycans that are also important for 2G12 neutralization and this serum blocked the binding of 2G12 to gp120. Our findings show that different fine specificities can achieve potent neutralization of HIV-1, yet this strong activity does not result in improved breadth. PMID:23326351

Ivermectin is a potent inhibitor of flavivirus replication specifically targeting NS3 helicase activity: new prospects for an old drug.

PubMed

Mastrangelo, Eloise; Pezzullo, Margherita; De Burghgraeve, Tine; Kaptein, Suzanne; Pastorino, Boris; Dallmeier, Kai; de Lamballerie, Xavier; Neyts, Johan; Hanson, Alicia M; Frick, David N; Bolognesi, Martino; Milani, Mario

2012-08-01

Infection with yellow fever virus (YFV), the prototypic mosquito-borne flavivirus, causes severe febrile disease with haemorrhage, multi-organ failure and a high mortality. Moreover, in recent years the Flavivirus genus has gained further attention due to re-emergence and increasing incidence of West Nile, dengue and Japanese encephalitis viruses. Potent and safe antivirals are urgently needed. Starting from the crystal structure of the NS3 helicase from Kunjin virus (an Australian variant of West Nile virus), we identified a novel, unexploited protein site that might be involved in the helicase catalytic cycle and could thus in principle be targeted for enzyme inhibition. In silico docking of a library of small molecules allowed us to identify a few selected compounds with high predicted affinity for the new site. Their activity against helicases from several flaviviruses was confirmed in in vitro helicase/enzymatic assays. The effect on the in vitro replication of flaviviruses was then evaluated. Ivermectin, a broadly used anti-helminthic drug, proved to be a highly potent inhibitor of YFV replication (EC₅₀ values in the sub-nanomolar range). Moreover, ivermectin inhibited, although less efficiently, the replication of several other flaviviruses, i.e. dengue fever, Japanese encephalitis and tick-borne encephalitis viruses. Ivermectin exerts its effect at a timepoint that coincides with the onset of intracellular viral RNA synthesis, as expected for a molecule that specifically targets the viral helicase. The well-tolerated drug ivermectin may hold great potential for treatment of YFV infections. Furthermore, structure-based optimization may result in analogues exerting potent activity against flaviviruses other than YFV.

Structural definition of a potent macrophage activating factor derived from vitamin D3-binding protein with adjuvant activity for antibody production.

PubMed

Yamamoto, N

1996-10-01

Incubation of human vitamin D3-binding protein (Gc protein), with a mixture of immobilized beta-galactosidase and sialidase, efficiently generated a potent macrophage activating factor, a protein with N-acetylgalactosamine as the remaining sugar. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase, and isolation of the intermediates with immobilized lectins, revealed that either sequence of hydrolysis of Gc glycoprotein by these glycosidases yields the macrophage-activating factor, implying that Gc protein carries a trisaccharide composed of N-acetylgalactosamine and dibranched galactose and sialic acid termini. A 3 hr incubation of mouse peritoneal macrophages with picomolar amounts of the enzymatically generated macrophage-activating factor (GcMAF) resulted in a greatly enhanced phagocytic activity. Administration of a minute amount (10-50 pg/mouse) of GcMAF resulted in a seven- to nine-fold enhanced phagocytic activity of macrophages. Injection of sheep red blood cells (SRBC) along with GcMAF into mice produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days.

Identification of a Potent Tryptophan-based TRPM8 Antagonist With in vivo Analgesic Activity.

PubMed

Bertamino, Alessia; Iraci, Nunzio; Ostacolo, Carmine; Ambrosino, Paolo; Musella, Simona; Di Sarno, Veronica; Ciaglia, Tania; Pepe, Giacomo; Sala, Marina; Soldovieri, Maria Virginia; Mosca, Ilaria; Gonzalez-Rodriguez, Sara; Fernández-Carvajal, Asia; Ferrer-Montiel, Antonio; Novellino, Ettore; Taglialatela, Maurizio; Campiglia, Pietro; Gomez-Monterrey, Isabel M

2018-06-25

TRPM8 has been implicated in nociception and pain and is currently regarded as an attractive target for the pharmacological treatment of neuropathic pain syndromes. A series of analogues of N,N'-dibenzyl tryptamine 1, a potent TRPM8 antagonist, were prepared and screened using a fluorescence-based in vitro assay based on menthol-evoked calcium influx in TRPM8 stably-transfected HEK293 cells. The tryptophan derivative 14 was identified as a potent (IC 50 0.2±0.2 nM) and selective TRPM8 antagonist. In vivo, 14 showed significant target coverage in both an icilin-induced WDS (at 1-30 mg/kg s.c.) and oxaliplatin-induced cold allodynia (at 0.1-1 μg s.c.) mice models. Molecular modeling studies identified the putative binding mode of these antagonists, suggesting that they could influence an interaction network between the S1-4 transmembrane segments and the TRP domains of the channel subunits. The tryptophan moiety provides a new pharmacophoric scaffold for the design of highly potent modulators of TRPM8-mediated pain.

The Curcumin Analog C-150, Influencing NF-κB, UPR and Akt/Notch Pathways Has Potent Anticancer Activity In Vitro and In Vivo

PubMed Central

Hackler, László; Ózsvári, Béla; Gyuris, Márió; Sipos, Péter; Fábián, Gabriella; Molnár, Eszter; Marton, Annamária; Faragó, Nóra; Mihály, József; Nagy, Lajos István; Szénási, Tibor; Diron, Andrea; Párducz, Árpád; Kanizsai, Iván; Puskás, László G.

2016-01-01

C-150 a Mannich-type curcumin derivative, exhibited pronounced cytotoxic effects against eight glioma cell lines at micromolar concentrations. Inhibition of cell proliferation by C-150 was mediated by affecting multiple targets as confirmed at transcription and protein level. C-150 effectively reduced the transcription activation of NFkB, inhibited PKC-alpha which are constitutively over-expressed in glioblastoma. The effects of C-150 on the Akt/ Notch signaling were also demonstrated in a Drosophila tumorigenesis model. C-150 reduced the number of tumors in Drosophila with similar efficacy to mitoxantrone. In an in vivo orthotopic glioma model, C-150 significantly increased the median survival of treated nude rats compared to control animals. The multi-target action of C-150, and its preliminary in vivo efficacy would render this curcumin analogue as a potent clinical candidate against glioblastoma. PMID:26943907

The Curcumin Analog C-150, Influencing NF-κB, UPR and Akt/Notch Pathways Has Potent Anticancer Activity In Vitro and In Vivo.

PubMed

Hackler, László; Ózsvári, Béla; Gyuris, Márió; Sipos, Péter; Fábián, Gabriella; Molnár, Eszter; Marton, Annamária; Faragó, Nóra; Mihály, József; Nagy, Lajos István; Szénási, Tibor; Diron, Andrea; Párducz, Árpád; Kanizsai, Iván; Puskás, László G

2016-01-01

C-150 a Mannich-type curcumin derivative, exhibited pronounced cytotoxic effects against eight glioma cell lines at micromolar concentrations. Inhibition of cell proliferation by C-150 was mediated by affecting multiple targets as confirmed at transcription and protein level. C-150 effectively reduced the transcription activation of NFkB, inhibited PKC-alpha which are constitutively over-expressed in glioblastoma. The effects of C-150 on the Akt/ Notch signaling were also demonstrated in a Drosophila tumorigenesis model. C-150 reduced the number of tumors in Drosophila with similar efficacy to mitoxantrone. In an in vivo orthotopic glioma model, C-150 significantly increased the median survival of treated nude rats compared to control animals. The multi-target action of C-150, and its preliminary in vivo efficacy would render this curcumin analogue as a potent clinical candidate against glioblastoma.

A chalcone with potent inhibiting activity against biofilm formation by nontypeable Haemophilus influenzae.

PubMed

Kunthalert, Duangkamol; Baothong, Sudarat; Khetkam, Pichit; Chokchaisiri, Suwadee; Suksamrarn, Apichart

2014-10-01

Nontypeable Haemophilus influenzae (NTHi), an important human respiratory pathogen, frequently causes biofilm infections. Currently, resistance of bacteria within the biofilm to conventional antimicrobials poses a major obstacle to effective medical treatment on a global scale. Novel agents that are effective against NTHi biofilm are therefore urgently required. In this study, a series of natural and synthetic chalcones with various chemical substituents were evaluated in vitro for their antibiofilm activities against strong biofilm-forming strains of NTHi. Of the test chalcones, 3-hydroxychalcone (chalcone 8) exhibited the most potent inhibitory activity, its mean minimum biofilm inhibitory concentration (MBIC50 ) being 16 μg/mL (71.35 μM), or approximately sixfold more active than the reference drug, azithromycin (MBIC50 419.68 μM). The inhibitory activity of chalcone 8, which is a chemically modified chalcone, appeared to be superior to those of the natural chalcones tested. Significantly, chalcone 8 inhibited biofilm formation by all studied NTHi strains, indicating that the antibiofilm activities of this compound occur across multiple strong-biofilm forming NTHi isolates of different clinical origins. According to antimicrobial and growth curve assays, chalcone 8 at concentrations that decreased biofilm formation did not affect growth of NTHi, suggesting the biofilm inhibitory effect of chalcone 8 is non-antimicrobial. In terms of structure-activity relationship, the possible substituent on the chalcone backbone required for antibiofilm activity is discussed. These findings indicate that 3-hydroxychalcone (chalcone 8) has powerful antibiofilm activity and suggest the potential application of chalcone 8 as a new therapeutic agent for control of NTHi biofilm-associated infections. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.

Discovery of novel 4-anilinoquinazoline derivatives as potent inhibitors of epidermal growth factor receptor with antitumor activity.

PubMed

Xu, Yun-Yun; Li, Si-Ning; Yu, Gao-Jian; Hu, Qing-Hua; Li, Huan-Qiu

2013-10-01

Two new series of new compounds containing a 6-amino-substituted group or 6-acrylamide-substituted group linked to a 4-anilinoquinazoline nucleus have been discovered as potential EGFR inhibitors. These compounds proved efficient effects on antiproliferative activity and EGFR-TK inhibitory activity. Especially, N(6)-((5-bromothiophen-2-yl)methyl)-N(4)-(3-chlorophenyl)quinazoline-4,6-diamine (5e), showed the most potent inhibitory activity (IC50=3.11μM for Hep G2, IC50=0.82μM for A549). The EGFR molecular docking model suggested that the new compound is nicely bound to the region of EGFR, and cell morphology by Hoechst stain experiment suggested that these compounds efficiently induced apoptosis of A549 cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

4-Bicyclic heteroaryl-piperidine derivatives as potent, orally bioavailable Stearoyl-CoA desaturase-1 (SCD1) inhibitors. Part 1: urea-based analogs.

PubMed

Yang, Shyh-Ming; Tang, Yuting; Zhang, Rui; Lu, Huajun; Kuo, Gee-Hong; Gaul, Michael D; Li, Yaxin; Ho, George; Conway, James G; Liang, Yin; Lenhard, James M; Demarest, Keith T; Murray, William V

2013-12-15

A new series of urea-based, 4-bicyclic heteroaryl-piperidine derivatives as potent SCD1 inhibitors is described. The structure-activity relationships focused on bicyclic heteroarenes and aminothiazole-urea portions are discussed. A trend of dose-dependent decrease in body weight gain in diet-induced obese (DIO) mice is also demonstrated. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Helical Short-Peptide Fusion Inhibitor with Highly Potent Activity against Human Immunodeficiency Virus Type 1 (HIV-1), HIV-2, and Simian Immunodeficiency Virus

PubMed Central

Xiong, Shengwen; Borrego, Pedro; Ding, Xiaohui; Zhu, Yuanmei; Martins, Andreia; Chong, Huihui

2016-01-01

ABSTRACT Human immunodeficiency virus type 2 (HIV-2) has already spread to different regions worldwide, and currently about 1 to 2 million people have been infected, calling for new antiviral agents that are effective on both HIV-1 and HIV-2 isolates. T20 (enfuvirtide), a 36-mer peptide derived from the C-terminal heptad repeat region (CHR) of gp41, is the only clinically approved HIV-1 fusion inhibitor, but it easily induces drug resistance and is not active on HIV-2. In this study, we first demonstrated that the M-T hook structure was also vital to enhancing the binding stability and inhibitory activity of diverse CHR-based peptide inhibitors. We then designed a novel short peptide (23-mer), termed 2P23, by introducing the M-T hook structure, HIV-2 sequences, and salt bridge-forming residues. Promisingly, 2P23 was a highly stable helical peptide with high binding to the surrogate targets derived from HIV-1, HIV-2, and simian immunodeficiency virus (SIV). Consistent with this, 2P23 exhibited potent activity in inhibiting diverse subtypes of HIV-1 isolates, T20-resistant HIV-1 mutants, and a panel of primary HIV-2 isolates, HIV-2 mutants, and SIV isolates. Therefore, we conclude that 2P23 has high potential to be further developed for clinical use, and it is also an ideal tool for exploring the mechanisms of HIV-1/2- and SIV-mediated membrane fusion. IMPORTANCE The peptide drug T20 is the only approved HIV-1 fusion inhibitor, but it is not active on HIV-2 isolates, which have currently infected 1 to 2 million people and continue to spread worldwide. Recent studies have demonstrated that the M-T hook structure can greatly enhance the binding and antiviral activities of gp41 CHR-derived inhibitors, especially for short peptides that are otherwise inactive. By combining the hook structure, HIV-2 sequence, and salt bridge-based strategies, the short peptide 2P23 has been successfully designed. 2P23 exhibits prominent advantages over many other peptide fusion inhibitors

Discovery of novel acetanilide derivatives as potent and selective beta3-adrenergic receptor agonists.

PubMed

Maruyama, Tatsuya; Onda, Kenichi; Hayakawa, Masahiko; Matsui, Tetsuo; Takasu, Toshiyuki; Ohta, Mitsuaki

2009-06-01

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, a novel series of acetanilide-based analogues were prepared and their biological activities were evaluated at the human beta3-, beta2-, and beta1-ARs. Among these compounds, 2-pyridylacetanilide (2f), pyrimidin-2-ylacetanilide (2u), and pyrazin-2-ylacetanilide (2v) derivatives exhibited potent agonistic activity at the beta3-AR with functional selectivity over the beta1- and beta2-ARs. In particular, compound 2u was found to be the most potent and selective beta3-AR agonist with an EC(50) value of 0.11 microM and no agonistic activity for either the beta1- or beta2-AR. In addition, 2f, 2u, and 2v showed significant hypoglycemic activity in a rodent diabetic model.

Synthesis and preliminary biological evaluation of potent and selective 2-(3-alkoxy-1-azetidinyl) quinolines as novel PDE10A inhibitors with improved solubility.

PubMed

Rzasa, Robert M; Frohn, Michael J; Andrews, Kristin L; Chmait, Samer; Chen, Ning; Clarine, Jeffrey G; Davis, Carl; Eastwood, Heather A; Horne, Daniel B; Hu, Essa; Jones, Adrie D; Kaller, Matthew R; Kunz, Roxanne K; Miller, Silke; Monenschein, Holger; Nguyen, Thomas; Pickrell, Alexander J; Porter, Amy; Reichelt, Andreas; Zhao, Xiaoning; Treanor, James J S; Allen, Jennifer R

2014-12-01

We report the discovery of a novel series of 2-(3-alkoxy-1-azetidinyl) quinolines as potent and selective PDE10A inhibitors. Structure-activity studies improved the solubility (pH 7.4) and maintained high PDE10A activity compared to initial lead compound 3, with select compounds demonstrating good oral bioavailability. X-ray crystallographic studies revealed two distinct binding modes to the catalytic site of the PDE10A enzyme. An ex vivo receptor occupancy assay in rats demonstrated that this series of compounds covered the target within the striatum.

Design, synthesis and molecular simulation studies of dihydrostilbene derivatives as potent tyrosinase inhibitors.

PubMed

Vontzalidou, Argyro; Zoidis, Grigoris; Chaita, Eliza; Makropoulou, Maria; Aligiannis, Nektarios; Lambrinidis, George; Mikros, Emmanuel; Skaltsounis, Alexios-Leandros

2012-09-01

The synthesis, molecular modeling and biological evaluation of substituted deoxybenzoins and optimized dihydrostilbenes are reported. Preliminary structure-activity relationship data were elucidated and lead compounds suitable for further optimization were discovered. Dihydrostilbene 7 is a particularly potent inhibitor (IC(50)=8.44 μM, more potent than kojic acid). Copyright © 2012 Elsevier Ltd. All rights reserved.

Identification of BMS-200475 as a potent and selective inhibitor of hepatitis B virus.

PubMed Central

Innaimo, S F; Seifer, M; Bisacchi, G S; Standring, D N; Zahler, R; Colonno, R J

1997-01-01

BMS-200475 is a novel carbocyclic 2'-deoxyguanosine analog found to possess potent and selective anti-hepatitis B virus (anti-HBV) activity. BMS-200475 is distinguished from guanosine by replacement of the natural furanose oxygen on the sugar moiety with an exo carbon-carbon double bond. In the HepG2 stably transfected cell line 2.2.15, BMS-200475 had a 50% effective concentration (EC50) of 3.75 nM against HBV, as determined by analysis of secreted HBV DNA. Structurally related compounds with adenine, iodouracil, or thymine base substitutions were significantly less potent or were inactive. Direct comparison of the antiviral activities of BMS-200475 with those of a variety of other nucleoside analogs, including lamivudine (EC50 = 116.26 nM), demonstrated the clearly superior in vitro potency of BMS-200475 in 2.2.15 cells. Intracellular HBV replicative intermediates were uniformly reduced when cells were treated with BMS-200475, but rebounded after treatment was terminated. The concentration of BMS-200475 causing 50% cytotoxicity in 2.2.15 cell cultures was 30 microM, approximately 8,000-fold greater than the concentration required to inhibit HBV replication in the same cell line. Treatment with BMS-200475 resulted in no apparent inhibitory effects on mitochondrial DNA content. PMID:9210663

The Pharmacological Heterogeneity of Nepenthone Analogs in Conferring Highly Selective and Potent κ-Opioid Agonistic Activities.

PubMed

Li, Wei; Long, Jian-Dong; Qian, Yuan-Yuan; Long, Yu; Xu, Xue-Jun; Wang, Yu-Jun; Shen, Qing; Wang, Zuo-Neng; Yang, Xi-Cheng; Xiao, Li; Sun, Hong-Peng; Xu, Yu-Long; Chen, Yi-Yi; Xie, Qiong; Wang, Yong-Hui; Shao, Li-Ming; Liu, Jing-Gen; Qiu, Zhui-Bai; Fu, Wei

2017-04-19

To develop novel analgesics with no side effects or less side effects than traditional opioids is highly demanded to treat opioid receptor mediated pain and addiction issues. Recently, κ-opioid receptor (KOR) has been established as an attractive target, although its selective agonists could bear heterogeneous pharmacological activities. In this study, we designed and synthesized two new series of nepenthone derivatives by inserting a spacer (carbonyl) between 6α,14α-endo-ethenylthebaine and the 7α-phenyl substitution of the skeleton and by substituting the 17-N-methyl group with a cyclopropylmethyl group. We performed in vitro tests (binding and functional assays) and molecular docking operations on our newly designed compounds. The results of wet-experimental measures and modeled binding structures demonstrate that these new compounds are selective KOR agonists with nanomolar level affinities. Compound 4 from these new derivatives showed the highest affinity (K i = 0.4 ± 0.1 nM) and the highest selectivity (μ/κ = 339, δ/κ = 2034) toward KOR. The in vivo tests revealed that compound 4 is able to induce stronger (ED 50 = 2.1 mg/kg) and much longer antinociceptive effect than that of the typical KOR agonist U50488H (ED 50 = 4.4 mg/kg). Therefore, compound 4 can be used as a perfect lead compound for future design of potent analgesics acting through KOR.

Prevalence of potent skin sensitizers in oxidative hair dye products in Korea.

PubMed

Kim, Hyunji; Kim, Kisok

2016-09-01

The objective of the present study was to elucidate the prevalence of potent skin sensitizers in oxidative hair dye products manufactured by Korean domestic companies. A database on hair dye products made by domestic companies and selling in the Korean market in 2013 was used to obtain information on company name, brand name, quantity of production, and ingredients. The prevalence of substances categorized as potent skin sensitizers was calculated using the hair dye ingredient database, and the pattern of concomitant presence of hair dye ingredients was analyzed using network analysis software. A total of 19 potent skin sensitizers were identified from a database that included 99 hair dye products manufactured by Korean domestic companies. Among 19 potent skin sensitizers, the four most frequent were resorcinol, m-aminophenol, p-phenylenediamine (PPD), and p-aminophenol; these four skin-sensitizing ingredients were found in more than 50% of the products studied. Network analysis showed that resorcinol, m-aminophenol, and PPD existed together in many hair dye products. In 99 products examined, the average product contained 4.4 potent sensitizers, and 82% of the products contained four or more skin sensitizers. The present results demonstrate that oxidative hair dye products made by Korean domestic manufacturers contain various numbers and types of potent skin sensitizers. Furthermore, these results suggest that some hair dye products should be used with caution to prevent adverse effects on the skin, including allergic contact dermatitis.

A new series of potent benzodiazepine gamma-secretase inhibitors.

PubMed

Churcher, Ian; Ashton, Kate; Butcher, John W; Clarke, Earl E; Harrison, Timothy; Lewis, Huw D; Owens, Andrew P; Teall, Martin R; Williams, Susie; Wrigley, Jonathan D J

2003-01-20

A new series of benzodiazepine-containing gamma-secretase inhibitors with potential use in the treatment of Alzheimer's disease is disclosed. Structure-activity relationships of the pendant hydrocinnamate side-chain which led to the preparation of highly potent inhibitors are described.

Aspartate aminotransferase is potently inhibited by copper complexes: Exploring copper complex-binding proteome.

PubMed

Jia, Yuqi; Lu, Liping; Yuan, Caixia; Feng, Sisi; Zhu, Miaoli

2017-05-01

Recent researches indicated that a copper complex-binding proteome that potently interacted with copper complexes and then influenced cellular metabolism might exist in organism. In order to explore the copper complex-binding proteome, a copper chelating ion-immobilized affinity chromatography (Cu-IMAC) column and mass spectrometry were used to separate and identify putative Cu-binding proteins in primary rat hepatocytes. A total of 97 putative Cu-binding proteins were isolated and identified. Five higher abundance proteins, aspartate aminotransferase (AST), malate dehydrogenase (MDH), catalase (CAT), calreticulin (CRT) and albumin (Alb) were further purified using a SP-, and (or) Q-Sepharose Fast Flow column. The interaction between the purified proteins and selected 11 copper complexes and CuCl 2 was investigated. The enzymes inhibition tests demonstrated that AST was potently inhibited by copper complexes while MDH and CAT were weakly inhibited. Schiff-based copper complexes 6 and 7 potently inhibited AST with the IC 50 value of 3.6 and 7.2μM, respectively and exhibited better selectivity over MDH and CAT. Fluorescence titration results showed the two complexes tightly bound to AST with binding constant of 3.89×10 6 and 3.73×10 6 M -1 , respectively and a stoichiometry ratio of 1:1. Copper complex 6 was able to enter into HepG2 cells and further inhibit intracellular AST activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Potent neutralizing monoclonal antibodies against Ebola virus infection

PubMed Central

Zhang, Qi; Gui, Miao; Niu, Xuefeng; He, Shihua; Wang, Ruoke; Feng, Yupeng; Kroeker, Andrea; Zuo, Yanan; Wang, Hua; Wang, Ying; Li, Jiade; Li, Chufang; Shi, Yi; Shi, Xuanling; Gao, George F.; Xiang, Ye; Qiu, Xiangguo; Chen, Ling; Zhang, Linqi

2016-01-01

Ebola virus infections cause a deadly hemorrhagic disease for which no vaccines or therapeutics has received regulatory approval. Here we show isolation of three (Q206, Q314 and Q411) neutralizing monoclonal antibodies (mAbs) against the surface glycoprotein (GP) of Ebola virus identified in West Africa in 2014 through sequential immunization of Chinese rhesus macaques and antigen-specific single B cell sorting. These mAbs demonstrated potent neutralizing activities against both pseudo and live Ebola virus independent of complement. Biochemical, single particle EM, and mutagenesis analysis suggested Q206 and Q411 recognized novel epitopes in the head while Q314 targeted the glycan cap in the GP1 subunit. Q206 and Q411 appeared to influence GP binding to its receptor NPC1. Treatment with these mAbs provided partial but significant protection against disease in a mouse model of Ebola virus infection. These novel mAbs could serve as promising candidates for prophylactic and therapeutic interventions against Ebola virus infection. PMID:27181584

Potent neutralizing monoclonal antibodies against Ebola virus infection.

PubMed

Zhang, Qi; Gui, Miao; Niu, Xuefeng; He, Shihua; Wang, Ruoke; Feng, Yupeng; Kroeker, Andrea; Zuo, Yanan; Wang, Hua; Wang, Ying; Li, Jiade; Li, Chufang; Shi, Yi; Shi, Xuanling; Gao, George F; Xiang, Ye; Qiu, Xiangguo; Chen, Ling; Zhang, Linqi

2016-05-16

Ebola virus infections cause a deadly hemorrhagic disease for which no vaccines or therapeutics has received regulatory approval. Here we show isolation of three (Q206, Q314 and Q411) neutralizing monoclonal antibodies (mAbs) against the surface glycoprotein (GP) of Ebola virus identified in West Africa in 2014 through sequential immunization of Chinese rhesus macaques and antigen-specific single B cell sorting. These mAbs demonstrated potent neutralizing activities against both pseudo and live Ebola virus independent of complement. Biochemical, single particle EM, and mutagenesis analysis suggested Q206 and Q411 recognized novel epitopes in the head while Q314 targeted the glycan cap in the GP1 subunit. Q206 and Q411 appeared to influence GP binding to its receptor NPC1. Treatment with these mAbs provided partial but significant protection against disease in a mouse model of Ebola virus infection. These novel mAbs could serve as promising candidates for prophylactic and therapeutic interventions against Ebola virus infection.

Novel depsides as potential anti-inflammatory agents with potent inhibitory activity against Escherichia coli-induced interleukin-8 production.

PubMed

Lv, Peng-Cheng; Xiong, Jing; Chen, Jin; Wang, Kai-Rui; Mao, Wen-Jun; Zhu, Hai-Liang

2010-08-01

Sixteen novel depsides were synthesized for the first time. Their chemical structures were clearly determined by (1)H NMR, ESI mass spectra, and elemental analyses. All the compounds were assayed for antibacterial activities against three Gram-positive bacterial strains (Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, and Streptococcus faecalis ATCC 9790) and three Gram-negative bacterial strains (Escherichia coli ATCC 35218, Pseudomonas aeruginosa ATCC 13525, and Enterobacter cloacae ATCC 13047) by the MTT method. Compound 2-(2-methoxy-2-oxoethyl)phenyl 5-bromonicotinate (5) exhibited significant antibacterial activities against E. coli ATCC 35218 with an MIC of 0.78 microg/mL, which was superior to the positive control kanamycin B. In addition, compound 5 showed potent inhibitory activity against E. coli-induced interleukin-8 production.

Antagonistic Potential of Native Trichoderma viride Strain against Potent Tea Fungal Pathogens in North East India.

PubMed

Naglot, A; Goswami, S; Rahman, I; Shrimali, D D; Yadav, Kamlesh K; Gupta, Vikas K; Rabha, Aprana Jyoti; Gogoi, H K; Veer, Vijay

2015-09-01

Indigenous strains of Trichoderma species isolated from rhizosphere soils of Tea gardens of Assam, north eastern state of India were assessed for in vitro antagonism against two important tea fungal pathogens namely Pestalotia theae and Fusarium solani. A potent antagonist against both tea pathogenic fungi, designated as SDRLIN1, was selected and identified as Trichoderma viride. The strain also showed substantial antifungal activity against five standard phytopathogenic fungi. Culture filtrate collected from stationary growth phase of the antagonist demonstrated a significantly higher degree of inhibitory activity against all the test fungi, demonstrating the presence of an optimal blend of extracellular antifungal metabolites. Moreover, quantitative enzyme assay of exponential and stationary culture filtrates revealed that the activity of cellulase, β-1,3-glucanase, pectinase, and amylase was highest in the exponential phase, whereas the activity of proteases and chitinase was noted highest in the stationary phase. Morphological changes such as hyphal swelling and distortion were also observed in the fungal pathogen grown on potato dextrose agar containing stationary phase culture filtrate. Moreover, the antifungal activity of the filtrate was significantly reduced but not entirely after heat or proteinase K treatment, demonstrating substantial role of certain unknown thermostable antifungal compound(s) in the inhibitory activity.

Antagonistic Potential of Native Trichoderma viride Strain against Potent Tea Fungal Pathogens in North East India

PubMed Central

Naglot, A.; Goswami, S.; Rahman, I.; Shrimali, D. D.; Yadav, Kamlesh K.; Gupta, Vikas K.; Rabha, Aprana Jyoti; Gogoi, H. K.; Veer, Vijay

2015-01-01

Indigenous strains of Trichoderma species isolated from rhizosphere soils of Tea gardens of Assam, north eastern state of India were assessed for in vitro antagonism against two important tea fungal pathogens namely Pestalotia theae and Fusarium solani. A potent antagonist against both tea pathogenic fungi, designated as SDRLIN1, was selected and identified as Trichoderma viride. The strain also showed substantial antifungal activity against five standard phytopathogenic fungi. Culture filtrate collected from stationary growth phase of the antagonist demonstrated a significantly higher degree of inhibitory activity against all the test fungi, demonstrating the presence of an optimal blend of extracellular antifungal metabolites. Moreover, quantitative enzyme assay of exponential and stationary culture filtrates revealed that the activity of cellulase, β-1,3-glucanase, pectinase, and amylase was highest in the exponential phase, whereas the activity of proteases and chitinase was noted highest in the stationary phase. Morphological changes such as hyphal swelling and distortion were also observed in the fungal pathogen grown on potato dextrose agar containing stationary phase culture filtrate. Moreover, the antifungal activity of the filtrate was significantly reduced but not entirely after heat or proteinase K treatment, demonstrating substantial role of certain unknown thermostable antifungal compound(s) in the inhibitory activity. PMID:26361476

A novel human model of the neurodegenerative disease GM1 gangliosidosis using induced pluripotent stem cells demonstrates inflammasome activation.

PubMed

Son, Mi-Young; Kwak, Jae Eun; Seol, Binna; Lee, Da Yong; Jeon, Hyejin; Cho, Yee Sook

2015-09-01

GM1 gangliosidosis (GM1) is an inherited neurodegenerative disorder caused by mutations in the lysosomal β-galactosidase (β-gal) gene. Insufficient β-gal activity leads to abnormal accumulation of GM1 gangliosides in tissues, particularly in the central nervous system, resulting in progressive neurodegeneration. Here, we report an in vitro human GM1 model, based on induced pluripotent stem cell (iPSC) technology. Neural progenitor cells differentiated from GM1 patient-derived iPSCs (GM1-NPCs) recapitulated the biochemical and molecular phenotypes of GM1, including defective β-gal activity and increased lysosomes. Importantly, the characterization of GM1-NPCs established that GM1 is significantly associated with the activation of inflammasomes, which play a critical role in the pathogenesis of various neurodegenerative diseases. Specific inflammasome inhibitors potently alleviated the disease-related phenotypes of GM1-NPCs in vitro and in vivo. Our data demonstrate that GM1-NPCs are a valuable in vitro human GM1 model and suggest that inflammasome activation is a novel target pathway for GM1 drug development. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Trifluorothymidine exhibits potent antitumor activity via the induction of DNA double-strand breaks.

PubMed

Suzuki, Norihiko; Nakagawa, Fumio; Nukatsuka, Mamoru; Fukushima, Masakazu

2011-05-01

TAS-102 is an oral anticancer drug composed of trifluorothymidine (TFT) and TPI (an inhibitor of thymidine phosphorylase that strongly inhibits the biodegradation of TFT). Similar to 5-fluorouracil (5FU) and 5-fluoro-2'-deoxyuridine (FdUrd), TFT also inhibits thymidylate synthase (TS), a rate-limiting enzyme of DNA biosynthesis, and is incorporated into DNA. TFT exhibits an anticancer effect on colorectal cancer cells that have acquired 5FU and/or FdUrd resistance as a result of the overexpression of TS. Therefore, we examined the mode of action of TFT-induced DNA damage after its incorporation into DNA. When HeLa cells were treated with TFT, the number of ring-open aldehyde forms at apurinic/apyrimidinic sites increased in a dose-dependent manner, although we previously reported that no detectable excisions of TFT paired to adenine were observed using uracil DNA glycosylases, thymine DNA glycosylase or methyl-CpG binding domain 4 and HeLa whole cell extracts. To investigate the functional mechanism of TFT-induced DNA damage, we measured the phosphorylation of ATR, ATM, BRCA2, chk1 and chk2 in nuclear extracts of HeLa cells after 0, 24, 48 or 72 h of exposure to an IC(50) concentration of TFT, FdUrd or 5FU using Western blot analysis or an enzyme-linked immunosorbent assay (ELISA). Unlike FdUrd and 5FU, TFT resulted in an earlier phosphorylation of ATR and chk1 proteins after only 24 h of exposure, while phosphorylated ATM, BRCA2 and chk2 proteins were detected after more than 48 h of exposure to TFT. These results suggest that TFT causes single-strand breaks followed by double-strand breaks in the DNA of TFT-treated cells. TFT (as TAS-102) showed a more potent antitumor activity than oral 5FU on CO-3 colon cancer xenografts in mice, and such antitumor potency was supported by the increased number of double-strand breaks occurring after single-strand breaks in the DNA of the TFT-treated tumors. These results suggest that TFT causes single-strand breaks after its

Ortho Group Activation of a Bromopyrrole Ester in Suzuki-Miyaura Cross-Coupling Reactions: Application to the Synthesis of New Microtubule Depolymerizing Agents with Potent Cytotoxic Activities

PubMed Central

Gupton, John T.; Yeudall, Scott; Telang, Nakul; Hoerrner, Megan; Huff, Ellis; Crawford, Evan; Lounsbury, Katie; Kimmel, Michael; Curry, William; Harrison, Andrew; Juekun, Wen; Shimozono, Alex; Ortolani, Joe; Lescalleet, Kristin; Patteson, Jon; Moore-Stoll, Veronica; Rohena, Cristina C.; Mooberry, Susan L.; Obaidullah, Ahmad J.; Kellogg, Glen E.; Sikorski, James A.

2017-01-01

New microtubule depolymerizing agents with potent cytotoxic activities have been prepared with a 5-cyano or 5-oximino group attached to a pyrrole core. The utilization of ortho activation of a bromopyrrole ester to facilitate successful Suzuki-Miyaura cross-coupling reactions was a key aspect of the synthetic methodology. This strategy allows for control of regiochemistry with the attachment of four completely different groups at the 2, 3, 4 and 5 positions of the pyrrole scaffold. Biological evaluations and molecular modeling studies are reported for these examples. PMID:28433513

Ivermectin is a potent inhibitor of flavivirus replication specifically targeting NS3 helicase activity: new prospects for an old drug

PubMed Central

Mastrangelo, Eloise; Pezzullo, Margherita; De Burghgraeve, Tine; Kaptein, Suzanne; Pastorino, Boris; Dallmeier, Kai; de Lamballerie, Xavier; Neyts, Johan; Hanson, Alicia M.; Frick, David N.; Bolognesi, Martino; Milani, Mario

2012-01-01

Objectives Infection with yellow fever virus (YFV), the prototypic mosquito-borne flavivirus, causes severe febrile disease with haemorrhage, multi-organ failure and a high mortality. Moreover, in recent years the Flavivirus genus has gained further attention due to re-emergence and increasing incidence of West Nile, dengue and Japanese encephalitis viruses. Potent and safe antivirals are urgently needed. Methods Starting from the crystal structure of the NS3 helicase from Kunjin virus (an Australian variant of West Nile virus), we identified a novel, unexploited protein site that might be involved in the helicase catalytic cycle and could thus in principle be targeted for enzyme inhibition. In silico docking of a library of small molecules allowed us to identify a few selected compounds with high predicted affinity for the new site. Their activity against helicases from several flaviviruses was confirmed in in vitro helicase/enzymatic assays. The effect on the in vitro replication of flaviviruses was then evaluated. Results Ivermectin, a broadly used anti-helminthic drug, proved to be a highly potent inhibitor of YFV replication (EC50 values in the sub-nanomolar range). Moreover, ivermectin inhibited, although less efficiently, the replication of several other flaviviruses, i.e. dengue fever, Japanese encephalitis and tick-borne encephalitis viruses. Ivermectin exerts its effect at a timepoint that coincides with the onset of intracellular viral RNA synthesis, as expected for a molecule that specifically targets the viral helicase. Conclusions The well-tolerated drug ivermectin may hold great potential for treatment of YFV infections. Furthermore, structure-based optimization may result in analogues exerting potent activity against flaviviruses other than YFV. PMID:22535622

Synthesis of gallinamide A analogues as potent falcipain inhibitors and antimalarials.

PubMed

Conroy, Trent; Guo, Jin T; Elias, Nabiha; Cergol, Katie M; Gut, Jiri; Legac, Jennifer; Khatoon, Lubna; Liu, Yang; McGowan, Sheena; Rosenthal, Philip J; Hunt, Nicholas H; Payne, Richard J

2014-12-26

Analogues of the natural product gallinamide A were prepared to elucidate novel inhibitors of the falcipain cysteine proteases. Analogues exhibited potent inhibition of falcipain-2 (FP-2) and falcipain-3 (FP-3) and of the development of Plasmodium falciparum in vitro. Several compounds were equipotent to chloroquine as inhibitors of the 3D7 strain of P. falciparum and maintained potent activity against the chloroquine-resistant Dd2 parasite. These compounds serve as promising leads for the development of novel antimalarial agents.

Synthesis and in vitro activity of dicationic indolyl diphenyl ethers as novel potent antibiotic agents against drug-resistant bacteria.

PubMed

Chen, Xiaofang; Hu, Xinxin; Wu, Yanbin; Liu, Yonghua; Bian, Cong; Nie, Tongying; You, Xuefu; Hu, Laixing

2017-02-15

A series of 4,4'-bis-[2-(6-N-substituted-amidino)indolyl] diphenyl ether have been synthesized and tested for their in vitro antibacterial activity including a range of Gram-positive and Gram-negative pathogens and cytotoxicity. Most of these compounds have mainly shown anti-Gram positive bacteria activities especially against drug resistant bacterial strains MRSA, MRSE and VRE. The anti-MRSA and anti-MRSE activities of compound 7a and 7j were more potent than that of the lead compound 2, levofloxacin and vancomycin. Interestingly, 7j had greatly improved anti negative bacterial activity, especially for the producing NDM-1 Klebsiella pneumonia strain and less toxic than that of the lead compound 2. Copyright © 2017 Elsevier Ltd. All rights reserved.

Icotinib (BPI-2009H), a novel EGFR tyrosine kinase inhibitor, displays potent efficacy in preclinical studies.

PubMed

Tan, Fenlai; Shen, Xiaoyan; Wang, Dechang; Xie, Guojian; Zhang, Xiaodong; Ding, Lieming; Hu, Yunyan; He, Wei; Wang, Yanping; Wang, Yinxiang

2012-05-01

Icotinib, one of the leading compounds selected from our compound library, was found to be a potent and specific epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with an IC(50) of 5 nM. When profiled with 88 kinases, Icotinib only showed meaningful inhibitory activity to EGFR and its mutants. Icotinib blocked EGFR-mediated intracellular tyrosine phosphorylation (IC(50)=45 nM) in the human epidermoid carcinoma A431 cell line and inhibits tumor cell proliferation. In vivo studies demonstrated that Icotinib exhibited potent dose-dependent antitumor effects in nude mice carrying a variety of human tumor-derived xenografts. The drug was well tolerated at doses up to 120 mg/kg/day in mice without mortality or significant body weight loss during the treatment. A head to head randomized, double blind phase III trial using Gefitinib as an active control for patients with advanced non-small cell lung cancer (NSCLC) was finished recently (Trial registration ID: NCT01040780). The data shows that Icotinib was non-inferior to Gefitinib in terms of median progression free survival (PFS) and safety superior favor to Icotinib compared to Gefitinib. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Bioactives in cactus (Opuntia ficus-indica) stems possess potent antioxidant and pro-apoptotic activities through COX-2 involvement.

PubMed

Kim, Jinhee; Soh, Soon Yil; Shin, Juha; Cho, Chi-Woung; Choi, Young Hee; Nam, Sang-Yong

2015-10-01

Bioactives extracted from cactus (Opuntia ficus-indica) stems were investigated for their chemopreventive activities using human cancer cells in vitro. The bioactives present in crude extracts were detected and quantified using high-performance liquid chromatography. Among all the extracts, such as hexane, ethyl acetate (EtOAc), acetone, methanol (MeOH), and MeOH:water (80:20), the MeOH extract had the highest amount of polyphenolic compounds and the acetone extract exhibited the most potent effect at scavenging the 2,2,-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS(•+) ) radical. In addition, most of the extracts, with the exception of hexane, exhibited significant cytotoxicity in human SW480 colon and MCF7 breast cancer cells. Overall, the SW480 cells were more sensitive than the MCF7 cells to the cytotoxic effect of the O. ficus-indica extracts (OFEs). Cell death by OFE treatment caused significant inhibition of cyclooxygenase-2 and increased the Bax/Bcl2 ratio in both SW480 and MCF7 cell lines. However, degradation of poly (ADP-ribose) polymerase was significantly increased by OFE only in the MCF7 cells, thereby inducing apoptosis. These findings demonstrate the health-benefit roles, including anti-oxidative and anti-proliferative activities as well as pro-apoptotic effects, of bioactive compounds in OFEs, suggesting a chemopreventive role in human cancer cells. © 2014 Society of Chemical Industry.

The angular structure of ONC201, a TRAIL pathway-inducing compound, determines its potent anti-cancer activity

PubMed Central

Wagner, Jessica; Kline, Christina Leah; Pottorf, Richard S.; Nallaganchu, Bhaskara Rao; Olson, Gary L.; Dicker, David T.; Allen, Joshua E.; El-Deiry, Wafik S.

2014-01-01

We previously identified TRAIL-inducing compound 10 (TIC10), also known as NSC350625 or ONC201, from a NCI chemical library screen as a small molecule that has potent anti-tumor efficacy and a benign safety profile in preclinical cancer models. The chemical structure that was originally published by Stahle, et. al. in the patent literature was described as an imidazo[1,2-a]pyrido[4,3-d]pyrimidine derivative. The NCI and others generally accepted this as the correct structure, which was consistent with the mass spectrometry analysis outlined in the publication by Allen et. al. that first reported the molecule's anticancer properties. A recent publication demonstrated that the chemical structure of ONC201 material from the NCI is an angular [3,4-e] isomer of the originally disclosed, linear [4,3-d] structure. Here we confirm by NMR and X-ray structural analysis of the dihydrochloride salt form that the ONC201 material produced by Oncoceutics is the angular [3,4-e] structure and not the linear structure originally depicted in the patent literature and by the NCI. Similarly, in accordance with our biological evaluation, the previously disclosed anti-cancer activity is associated with the angular structure and not the linear isomer. Together these studies confirm that ONC201, produced by Oncoceutics or obtained from the NCI, possesses an angular [3,4-e] structure that represents the highly active anti-cancer compound utilized in prior preclinical studies and now entering clinical trials in advanced cancers. PMID:25587031

The angular structure of ONC201, a TRAIL pathway-inducing compound, determines its potent anti-cancer activity.

PubMed

Wagner, Jessica; Kline, Christina Leah; Pottorf, Richard S; Nallaganchu, Bhaskara Rao; Olson, Gary L; Dicker, David T; Allen, Joshua E; El-Deiry, Wafik S

2014-12-30

We previously identified TRAIL-inducing compound 10 (TIC10), also known as NSC350625 or ONC201, from a NCI chemical library screen as a small molecule that has potent anti-tumor efficacy and a benign safety profile in preclinical cancer models. The chemical structure that was originally published by Stahle, et. al. in the patent literature was described as an imidazo[1,2-a]pyrido[4,3-d]pyrimidine derivative. The NCI and others generally accepted this as the correct structure, which was consistent with the mass spectrometry analysis outlined in the publication by Allen et. al. that first reported the molecule's anticancer properties. A recent publication demonstrated that the chemical structure of ONC201 material from the NCI is an angular [3,4-e] isomer of the originally disclosed, linear [4,3-d] structure. Here we confirm by NMR and X-ray structural analysis of the dihydrochloride salt form that the ONC201 material produced by Oncoceutics is the angular [3,4-e] structure and not the linear structure originally depicted in the patent literature and by the NCI. Similarly, in accordance with our biological evaluation, the previously disclosed anti-cancer activity is associated with the angular structure and not the linear isomer. Together these studies confirm that ONC201, produced by Oncoceutics or obtained from the NCI, possesses an angular [3,4-e] structure that represents the highly active anti-cancer compound utilized in prior preclinical studies and now entering clinical trials in advanced cancers.

Genomewide Analysis of the Antimicrobial Peptides in Python bivittatus and Characterization of Cathelicidins with Potent Antimicrobial Activity and Low Cytotoxicity.

PubMed

Kim, Dayeong; Soundrarajan, Nagasundarapandian; Lee, Juyeon; Cho, Hye-Sun; Choi, Minkyeung; Cha, Se-Yeoun; Ahn, Byeongyong; Jeon, Hyoim; Le, Minh Thong; Song, Hyuk; Kim, Jin-Hoi; Park, Chankyu

2017-09-01

In this study, we sought to identify novel antimicrobial peptides (AMPs) in Python bivittatus through bioinformatic analyses of publicly available genome information and experimental validation. In our analysis of the python genome, we identified 29 AMP-related candidate sequences. Of these, we selected five cathelicidin-like sequences and subjected them to further in silico analyses. The results showed that these sequences likely have antimicrobial activity. The sequences were named Pb-CATH1 to Pb-CATH5 according to their sequence similarity to previously reported snake cathelicidins. We predicted their molecular structure and then chemically synthesized the mature peptide for three putative cathelicidins and subjected them to biological activity tests. Interestingly, all three peptides showed potent antimicrobial effects against Gram-negative bacteria but very weak activity against Gram-positive bacteria. Remarkably, ΔPb-CATH4 showed potent activity against antibiotic-resistant clinical isolates and also was observed to possess very low hemolytic activity and cytotoxicity. ΔPb-CATH4 also showed considerable serum stability. Electron microscopic analysis indicated that ΔPb-CATH4 exerts its effects via toroidal pore preformation. Structural comparison of the cathelicidins identified in this study to previously reported ones revealed that these Pb-CATHs are representatives of a new group of reptilian cathelicidins lacking the acidic connecting domain. Furthermore, Pb-CATH4 possesses a completely different mature peptide sequence from those of previously described reptilian cathelicidins. These new AMPs may be candidates for the development of alternatives to or complements of antibiotics to control multidrug-resistant pathogens. Copyright © 2017 American Society for Microbiology.

Genomewide Analysis of the Antimicrobial Peptides in Python bivittatus and Characterization of Cathelicidins with Potent Antimicrobial Activity and Low Cytotoxicity

PubMed Central

Kim, Dayeong; Soundrarajan, Nagasundarapandian; Lee, Juyeon; Cho, Hye-sun; Choi, Minkyeung; Cha, Se-Yeoun; Ahn, Byeongyong; Jeon, Hyoim; Le, Minh Thong; Song, Hyuk; Kim, Jin-Hoi

2017-01-01

ABSTRACT In this study, we sought to identify novel antimicrobial peptides (AMPs) in Python bivittatus through bioinformatic analyses of publicly available genome information and experimental validation. In our analysis of the python genome, we identified 29 AMP-related candidate sequences. Of these, we selected five cathelicidin-like sequences and subjected them to further in silico analyses. The results showed that these sequences likely have antimicrobial activity. The sequences were named Pb-CATH1 to Pb-CATH5 according to their sequence similarity to previously reported snake cathelicidins. We predicted their molecular structure and then chemically synthesized the mature peptide for three putative cathelicidins and subjected them to biological activity tests. Interestingly, all three peptides showed potent antimicrobial effects against Gram-negative bacteria but very weak activity against Gram-positive bacteria. Remarkably, ΔPb-CATH4 showed potent activity against antibiotic-resistant clinical isolates and also was observed to possess very low hemolytic activity and cytotoxicity. ΔPb-CATH4 also showed considerable serum stability. Electron microscopic analysis indicated that ΔPb-CATH4 exerts its effects via toroidal pore preformation. Structural comparison of the cathelicidins identified in this study to previously reported ones revealed that these Pb-CATHs are representatives of a new group of reptilian cathelicidins lacking the acidic connecting domain. Furthermore, Pb-CATH4 possesses a completely different mature peptide sequence from those of previously described reptilian cathelicidins. These new AMPs may be candidates for the development of alternatives to or complements of antibiotics to control multidrug-resistant pathogens. PMID:28630199

A novel dioxygenation product of arachidonic acid possesses potent chemotactic activity for human polymorphonuclear leukocytes.

PubMed

Shak, S; Perez, H D; Goldstein, I M

1983-12-25

We have found that a novel dioxygenation product of arachidonic acid, 8(S),15(S)-dihydroxy-5,11-cis-9,13-trans-eicosatetraenoic acid (8,15-diHETE), possesses chemotactic activity for human polymorphonuclear leukocytes comparable to that of leukotriene B4. Authentic 8,15-diHETE, identified by gas chromatography-mass spectrometry, was prepared by treating arachidonic acid with soybean lipoxygenase and was purified by reverse-phase high performance liquid chromatography. Using a "leading front" assay, 8,15-diHETE exhibited significant chemotactic activity at a concentration of 5.0 ng/ml. Maximum chemotactic activity was observed at a concentration of 30 ng/ml. The 8,15-diHETE generated by mixed human leukocytes after stimulation with arachidonic acid and the calcium ionophore, A23187, exhibited quantitatively similar chemotactic activity. Two synthetic all-trans conjugated isomers of 8,15-diHETE, however, were not chemotactic at concentrations up to 500 ng/ml. In contrast to its potent chemotactic activity, 8,15-diHETE (at concentrations up to 10 micrograms/ml) was relatively inactive with respect to its ability to provoke either degranulation or generation of superoxide anion radicals by cytochalasin B-treated leukocytes. Both leukotriene B4 and 8,15-diHETE may be important mediators of inflammation.

Synthesis of a novel adamantyl nitroxide derivative with potent anti-hepatoma activity in vitro and in vivo

PubMed Central

Sun, Jin; Wang, Shan; Bu, Wei; Wei, Meng-Ying; Li, Wei-Wei; Yao, Min-Na; Ma, Zhong-Ying; Lu, Cheng-Tao; Li, Hui-Hui; Hu, Na-Ping; Zhang, En-Hu; Yang, Guo-Dong; Wen, Ai-Dong; Zhu, Xiao-He

2016-01-01

In this study, a novel adamantyl nitroxide derivative was synthesized and its antitumor activities in vitro and in vivo were investigated. The adamantyl nitroxide derivative 4 displayed a potent anticancer activity against all the tested human hepatoma cells, especially with IC50 of 68.1 μM in Bel-7404 cells, compared to the positive control 5-FU (IC50=607.7 μM). The significant inhibition of cell growth was also observed in xenograft mouse model, with low toxicity. Compound 4 suppressed the cell migration and invasion, induced the G2/M phase arrest. Further mechanistic studies revealed that compound 4 induced cell death, which was accompanied with damaging mitochondria, increasing the generation of intracellular reactive oxygen species, cleavages of caspase-9 and caspase-3, as well as activations of Bax and Bcl-2. These results confirmed that adamantyl nitroxide derivative exhibited selective antitumor activities via mitochondrial apoptosis pathway in Bel-7404 cells, and would be a potential anticancer agent for liver cancer. PMID:27429843

Hexahydroquinolines are Antimalarial Candidates with Potent Blood Stage and Transmission-Blocking Activity

PubMed Central

Vanaerschot, Manu; Lucantoni, Leonardo; Li, Tao; Combrinck, Jill M.; Ruecker, Andrea; Kumar, T.R. Santha; Rubiano, Kelly; Ferreira, Pedro E.; Siciliano, Giulia; Gulati, Sonia; Henrich, Philipp P.; Ng, Caroline L.; Murithi, James M.; Corey, Victoria C.; Duffy, Sandra; Lieberman, Ori J.; Veiga, M. Isabel; Sinden, Robert E.; Alano, Pietro; Delves, Michael J.; Sim, Kim Lee; Winzeler, Elizabeth A.; Egan, Timothy J.; Hoffman, Stephen L.; Avery, Vicky M.; Fidock, David A.

2017-01-01

Antimalarial compounds with dual therapeutic and transmission-blocking activity are desired as high-value partners for combination therapies. Here, we report the identification and characterization of hexahydroquinolines (HHQs) that show low nanomolar potency against both pathogenic and transmissible intra-erythrocytic forms of the malaria parasite Plasmodium falciparum. This activity translates into potent transmission-blocking potential, as shown by in vitro male gamete formation assays and reduced oocyst infection and prevalence in Anopheles mosquitoes. In vivo studies illustrated the ability of lead HHQs to suppress P. berghei blood-stage parasite proliferation. Resistance selection studies, confirmed by CRISPR/Cas9-based gene editing, identified the digestive vacuole membrane-spanning transporter PfMDR1 as a determinant of parasite resistance to HHQs. Hemoglobin and heme fractionation assays suggest a mode of action that results in reduced hemozoin levels and might involve inhibition of host hemoglobin uptake into intra-erythrocytic parasites. Furthermore, parasites resistant to HHQs displayed increased susceptibility to several first-line antimalarial drugs including lumefantrine, confirming that HHQs have a different mode of action than other antimalarials drugs for which PfMDR1 is known to confer resistance. This work evokes therapeutic strategies that combine opposing selective pressures on this parasite transporter as an approach to countering the emergence and transmission of multidrug-resistant P. falciparum malaria. PMID:28808258

Hexahydroquinolines are antimalarial candidates with potent blood-stage and transmission-blocking activity.

PubMed

Vanaerschot, Manu; Lucantoni, Leonardo; Li, Tao; Combrinck, Jill M; Ruecker, Andrea; Kumar, T R Santha; Rubiano, Kelly; Ferreira, Pedro E; Siciliano, Giulia; Gulati, Sonia; Henrich, Philipp P; Ng, Caroline L; Murithi, James M; Corey, Victoria C; Duffy, Sandra; Lieberman, Ori J; Veiga, M Isabel; Sinden, Robert E; Alano, Pietro; Delves, Michael J; Lee Sim, Kim; Winzeler, Elizabeth A; Egan, Timothy J; Hoffman, Stephen L; Avery, Vicky M; Fidock, David A

2017-10-01

Antimalarial compounds with dual therapeutic and transmission-blocking activity are desired as high-value partners for combination therapies. Here, we report the identification and characterization of hexahydroquinolines (HHQs) that show low nanomolar potency against both pathogenic and transmissible intra-erythrocytic forms of the malaria parasite Plasmodium falciparum. This activity translates into potent transmission-blocking potential, as shown by in vitro male gamete formation assays and reduced oocyst infection and prevalence in Anopheles mosquitoes. In vivo studies illustrated the ability of lead HHQs to suppress Plasmodium berghei blood-stage parasite proliferation. Resistance selection studies, confirmed by CRISPR-Cas9-based gene editing, identified the digestive vacuole membrane-spanning transporter PfMDR1 (P. falciparum multidrug resistance gene-1) as a determinant of parasite resistance to HHQs. Haemoglobin and haem fractionation assays suggest a mode of action that results in reduced haemozoin levels and might involve inhibition of host haemoglobin uptake into intra-erythrocytic parasites. Furthermore, parasites resistant to HHQs displayed increased susceptibility to several first-line antimalarial drugs, including lumefantrine, confirming that HHQs have a different mode of action to other antimalarials drugs for which PfMDR1 is known to confer resistance. This work evokes therapeutic strategies that combine opposing selective pressures on this parasite transporter as an approach to countering the emergence and transmission of multidrug-resistant P. falciparum malaria.

HYPOXIA-ACTIVATED PRO-DRUG TH-302 EXHIBITS POTENT TUMOUR SUPPRESSIVE ACTIVITY AND COOPERATES WITH CHEMOTHERAPY AGAINST OSTEOSARCOMA

PubMed Central

Liapis, Vasilios; Labrinidis, Agatha; Zinonos, Irene; Hay, Shelley; Ponomarev, Vladimir; Panagopoulos, Vasilios; DeNichilo, Mark; Ingman, Wendy; Atkins, Gerald J.; Findlay, David M.; Zannettino, Andrew CW.; Evdokiou, Andreas

2015-01-01

Tumour hypoxia is a major cause of treatment failure for a variety of malignancies. However, tumour hypoxia also offers treatment opportunities, exemplified by the development compounds that target hypoxic regions within tumours. TH-302 is a pro-drug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide (Br-IPM). When TH-302 is delivered to regions of hypoxia, Br-IPM, the DNA cross linking toxin, is released. In this study we assessed the cytotoxic activity of TH-302 against osteosarcoma cells in vitro and evaluated its anticancer efficacy as a single agent, and in combination with doxorubicin, in an orthotopic mouse model of human osteosarcoma (OS). In vitro, TH-302 was potently cytotoxic to osteosarcoma cells selectively under hypoxic conditions, whereas primary normal human osteoblasts were protected. Animals transplanted with OS cells directly into their tibiae and left untreated developed mixed osteolytic/osteosclerotic bone lesions and subsequently developed lung metastases. TH-302 reduced tumor burden in bone and cooperated with doxorubicin to protect bone from osteosarcoma induced bone destruction, while it also reduced lung metastases. TH-302 may therefore be an attractive therapeutic agent with strong activity as a single agent and in combination with chemotherapy against OS. PMID:25444931

Hypoxia-activated pro-drug TH-302 exhibits potent tumor suppressive activity and cooperates with chemotherapy against osteosarcoma.

PubMed

Liapis, Vasilios; Labrinidis, Agatha; Zinonos, Irene; Hay, Shelley; Ponomarev, Vladimir; Panagopoulos, Vasilios; DeNichilo, Mark; Ingman, Wendy; Atkins, Gerald J; Findlay, David M; Zannettino, Andrew C W; Evdokiou, Andreas

2015-02-01

Tumor hypoxia is a major cause of treatment failure for a variety of malignancies. However, tumor hypoxia also offers treatment opportunities, exemplified by the development compounds that target hypoxic regions within tumors. TH-302 is a pro-drug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide (Br-IPM). When TH-302 is delivered to regions of hypoxia, Br-IPM, the DNA cross linking toxin, is released. In this study we assessed the cytotoxic activity of TH-302 against osteosarcoma cells in vitro and evaluated its anticancer efficacy as a single agent, and in combination with doxorubicin, in an orthotopic mouse model of human osteosarcoma (OS). In vitro, TH-302 was potently cytotoxic to osteosarcoma cells selectively under hypoxic conditions, whereas primary normal human osteoblasts were protected. Animals transplanted with OS cells directly into their tibiae and left untreated developed mixed osteolytic/osteosclerotic bone lesions and subsequently developed lung metastases. TH-302 reduced tumor burden in bone and cooperated with doxorubicin to protect bone from osteosarcoma induced bone destruction, while it also reduced lung metastases. TH-302 may therefore be an attractive therapeutic agent with strong activity as a single agent and in combination with chemotherapy against OS. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

KINETIC CHARACTERIZATION AND MOLECULAR DOCKING OF A NOVEL, POTENT, AND SELECTIVE SLOW-BINDING INHIBITOR OF HUMAN CATHEPSIN L

PubMed Central

Shah, Parag P.; Myers, Michael C.; Beavers, Mary Pat; Purvis, Jeremy E.; Jing, Huiyan; Grieser, Heather J.; Sharlow, Elizabeth R.; Napper, Andrew D.; Huryn, Donna M.; Cooperman, Barry S.; Smith, Amos B.; Diamond, Scott L.

2008-01-01

A novel small molecule thiocarbazate (PubChem SID 26681509), a potent inhibitor of human cathepsin L (EC 3.4.22.15) with an IC50 of 56 nM, was developed following a 57,821 compound screen of the NIH Molecular Libraries Small Molecule Repository. After a 4 hr preincubation with cathepsin L, this compound became even more potent, demonstrating an IC50 of 1.0 nM. The thiocarbazate was determined to be a slow-binding and slowly reversible competitive inhibitor. Through a transient kinetic analysis for single-step reversibility, inhibition rate constants were kon = 24,000 M-1s-1 and koff = 2.2 × 10-5 s-1 (Ki = 0.89 nM). Molecular docking studies were undertaken using the experimentally-derived X-ray crystal structure of papain/CLIK-148 (1cvz.pdb). These studies revealed critical hydrogen bonding patterns of the thiocarbazate with key active site residues in papain. The thiocarbazate displayed 7- to 151-fold greater selectivity toward cathepsin L than papain and cathepsins B, K, V, and S with no activity against cathepsin G. The inhibitor demonstrated a lack of toxicity in human aortic endothelial cells and zebrafish. Additionally, the thiocarbazate inhibited in vitro propagation of malaria parasite Plasmodium falciparum with an IC50 of 15.4 μM and inhibited Leishmania major with an IC50 of 12.5 μM. PMID:18403718

Potent D-peptide inhibitors of HIV-1 entry

PubMed Central

Welch, Brett D.; VanDemark, Andrew P.; Heroux, Annie; Hill, Christopher P.; Kay, Michael S.

2007-01-01

During HIV-1 entry, the highly conserved gp41 N-trimer pocket region becomes transiently exposed and vulnerable to inhibition. Using mirror-image phage display and structure-assisted design, we have discovered protease-resistant D-amino acid peptides (D-peptides) that bind the N-trimer pocket with high affinity and potently inhibit viral entry. We also report high-resolution crystal structures of two of these D-peptides in complex with a pocket mimic that suggest sources of their high potency. A trimeric version of one of these peptides is the most potent pocket-specific entry inhibitor yet reported by three orders of magnitude (IC50 = 250 pM). These results are the first demonstration that D-peptides can form specific and high-affinity interactions with natural protein targets and strengthen their promise as therapeutic agents. The D-peptides described here address limitations associated with current L-peptide entry inhibitors and are promising leads for the prevention and treatment of HIV/AIDS. PMID:17942675

Discovery of novel high potent and cellular active ADC type PTP1B inhibitors with selectivity over TC-PTP via modification interacting with C site.

PubMed

Du, Yongli; Zhang, Yanhui; Ling, Hao; Li, Qunyi; Shen, Jingkang

2018-01-20

PTP1B serving as a key negative regulator of insulin signaling is a novel target for type 2 diabetes and obesity. Modification at ring B of N-{4-[(3-Phenyl-ureido)-methyl]-phenyl}-methane-sulfonamide template to interact with residues Arg47 and Lys41 in the C site of PTP1B by molecular docking aided design resulted in the discovery of a series of novel high potent and selective inhibitors of PTP1B. The structure activity relationship interacting with the C site of PTP1B was well illustrated. Compounds 8 and 18 were shown to be the high potent and most promising PTP1B inhibitors with cellular activity and great selectivity over the highly homologous TCPTP and other PTPs. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Diphenyl difluoroketone: a curcumin derivative with potent in vivo anticancer activity.

PubMed

Subramaniam, Dharmalingam; May, Randal; Sureban, Sripathi M; Lee, Katherine B; George, Robert; Kuppusamy, Periannan; Ramanujam, Rama P; Hideg, Kalman; Dieckgraefe, Brian K; Houchen, Courtney W; Anant, Shrikant

2008-03-15

Diphenyl difluoroketone (EF24), a molecule having structural similarity to curcumin, was reported to inhibit proliferation of a variety of cancer cells in vitro. However, the efficacy and in vivo mechanism of action of EF24 in gastrointestinal cancer cells have not been investigated. Here, we assessed the in vivo therapeutic effects of EF24 on colon cancer cells. Using hexosaminidase assay, we determined that EF24 inhibits proliferation of HCT-116 and HT-29 colon and AGS gastric adenocarcinoma cells but not of mouse embryo fibroblasts. Furthermore, the cancer cells showed increased levels of activated caspase-3 and increased Bax to Bcl-2 and Bax to Bcl-xL ratios, suggesting that the cells were undergoing apoptosis. At the same time, cell cycle analysis showed that there was an increased number of cells in the G(2)-M phase. To determine the effects of EF24 in vivo, HCT-116 colon cancer xenografts were established in nude mice and EF24 was given i.p. EF24 significantly suppressed the growth of colon cancer tumor xenografts. Immunostaining for CD31 showed that there was a lower number of microvessels in the EF24-treated animals coupled with decreased cyclooxygenase-2, interleukin-8, and vascular endothelial growth factor mRNA and protein expression. Western blot analyses also showed decreased AKT and extracellular signal-regulated kinase activation in the tumors. Taken together, these data suggest that the novel curcumin-related compound EF24 is a potent antitumor agent that induces caspase-mediated apoptosis during mitosis and has significant therapeutic potential for gastrointestinal cancers.

The Interglomerular Circuit Potently Inhibits Olfactory Bulb Output Neurons by Both Direct and Indirect Pathways.

PubMed

Liu, Shaolin; Puche, Adam C; Shipley, Michael T

2016-09-14

Sensory processing shapes our perception. In mammals, odor information is encoded by combinatorial activity patterns of olfactory bulb (OB) glomeruli. Glomeruli are richly interconnected by short axon cells (SACs), which form the interglomerular circuit (IGC). It is unclear how the IGC impacts OB output to downstream neural circuits. We combined in vitro and in vivo electrophysiology with optogenetics in mice and found the following: (1) the IGC potently and monosynaptically inhibits the OB output neurons mitral/tufted cells (MTCs) by GABA release from SACs: (2) gap junction-mediated electrical coupling is strong for the SAC→MTC synapse, but negligible for the SAC→ETC synapse; (3) brief IGC-mediated inhibition is temporally prolonged by the intrinsic properties of MTCs; and (4) sniff frequency IGC activation in vivo generates persistent MTC inhibition. These findings suggest that the temporal sequence of glomerular activation by sensory input determines which stimulus features are transmitted to downstream olfactory networks and those filtered by lateral inhibition. Odor identity is encoded by combinatorial patterns of activated glomeruli, the initial signal transformation site of the olfactory system. Lateral circuit processing among activated glomeruli modulates olfactory signal transformation before transmission to higher brain centers. Using a combination of in vitro and in vivo optogenetics, this work demonstrates that interglomerular circuitry produces potent inhibition of olfactory bulb output neurons via direct chemical and electrical synapses as well as by indirect pathways. The direct inhibitory synaptic input engages mitral cell intrinsic membrane properties to generate inhibition that outlasts the initial synaptic action. Copyright © 2016 the authors 0270-6474/16/369604-14$15.00/0.

The Interglomerular Circuit Potently Inhibits Olfactory Bulb Output Neurons by Both Direct and Indirect Pathways

PubMed Central

Puche, Adam C.; Shipley, Michael T.

2016-01-01

Sensory processing shapes our perception. In mammals, odor information is encoded by combinatorial activity patterns of olfactory bulb (OB) glomeruli. Glomeruli are richly interconnected by short axon cells (SACs), which form the interglomerular circuit (IGC). It is unclear how the IGC impacts OB output to downstream neural circuits. We combined in vitro and in vivo electrophysiology with optogenetics in mice and found the following: (1) the IGC potently and monosynaptically inhibits the OB output neurons mitral/tufted cells (MTCs) by GABA release from SACs: (2) gap junction-mediated electrical coupling is strong for the SAC→MTC synapse, but negligible for the SAC→ETC synapse; (3) brief IGC-mediated inhibition is temporally prolonged by the intrinsic properties of MTCs; and (4) sniff frequency IGC activation in vivo generates persistent MTC inhibition. These findings suggest that the temporal sequence of glomerular activation by sensory input determines which stimulus features are transmitted to downstream olfactory networks and those filtered by lateral inhibition. SIGNIFICANCE STATEMENT Odor identity is encoded by combinatorial patterns of activated glomeruli, the initial signal transformation site of the olfactory system. Lateral circuit processing among activated glomeruli modulates olfactory signal transformation before transmission to higher brain centers. Using a combination of in vitro and in vivo optogenetics, this work demonstrates that interglomerular circuitry produces potent inhibition of olfactory bulb output neurons via direct chemical and electrical synapses as well as by indirect pathways. The direct inhibitory synaptic input engages mitral cell intrinsic membrane properties to generate inhibition that outlasts the initial synaptic action. PMID:27629712

One-pot, multicomponent synthesis of 2,3-disubstituted quinazolin-ones with potent and selective activity against Toxoplasma gondii.

PubMed

Brown, Carla E; Kong, Tiffany; Bordón, Claudia; Yolken, Robert; Jones-Brando, Lorraine; McNulty, James

2018-05-15

The discovery of two quinazolinones with selective, single-digit micromolar activity (IC 50  = 6-7 µM) against the tachyzoites of the apicomplexan parasite Toxoplasma gondii is reported. These potent and selective third generation derivatives contain a benzyloxybenzyl substituent at C2 and a bulky aliphatic moiety at N3. Here we show that these quinazolinones inhibit T. gondii tachyzoite replication in an established infection, but do not significantly affect host cell invasion by the tachyzoites. Copyright © 2018 Elsevier Ltd. All rights reserved.

Triclosan Derivatives: Towards Potent Inhibitors of Drug-Sensitive and Drug-Resistant Mycobacterium tuberculosis

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

Freundlich, Joel S.; Wang, Feng; Vilchèze, Catherine

Isoniazid (INH) is a frontline antitubercular drug that inhibits the enoyl acyl carrier protein reductase InhA. Novel inhibitors of InhA that are not cross-resistant to INH represent a significant goal in antitubercular chemotherapy. The design, synthesis, and biological activity of a series of triclosan-based inhibitors is reported, including their promising efficacy against INH-resistant strains of M. tuberculosis. Triclosan has been previously shown to inhibit InhA, an essential enoyl acyl carrier protein reductase involved in mycolic acid biosynthesis, the inhibition of which leads to the lysis of Mycobacterium tuberculosis. Using a structure-based drug design approach, a series of 5-substituted triclosan derivativesmore » was developed. Two groups of derivatives with alkyl and aryl substituents, respectively, were identified with dramatically enhanced potency against purified InhA. The most efficacious inhibitor displayed an IC{sub 50} value of 21 nM, which was 50-fold more potent than triclosan. X-ray crystal structures of InhA in complex with four triclosan derivatives revealed the structural basis for the inhibitory activity. Six selected triclosan derivatives were tested against isoniazid-sensitive and resistant strains of M. tuberculosis. Among those, the best inhibitor had an MIC value of 4.7 {mu}g mL{sup -1} (13 {mu}M), which represents a tenfold improvement over the bacteriocidal activity of triclosan. A subset of these triclosan analogues was more potent than isoniazid against two isoniazid-resistant M. tuberculosis strains, demonstrating the significant potential for structure-based design in the development of next generation antitubercular drugs.« less

Substituted N-aryl-6-pyrimidinones: A new class of potent, selective, and orally active p38 MAP kinase inhibitors

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

Devadas, Balekudru; Selness, Shaun R.; Xing, Li

2012-02-28

A novel series of highly potent and selective p38 MAP kinase inhibitors was developed originating from a substituted N-aryl-6-pyrimidinone scaffold. SAR studies coupled with in vivo evaluations in rat arthritis model culminated in the identification of 10 with excellent oral efficacy. Compound 10 exhibited a significantly enhanced dissolution rate compared to 1, translating to a high oral bioavailability (>90%) in rat. In animal studies 10 inhibited LPS-stimulated production of tumor necrosis factor-{alpha} in a dose-dependent manner and demonstrated robust efficacy comparable to dexamethasone in a rat streptococcal cell wall-induced arthritis model.

A potent anti-HB-EGF monoclonal antibody inhibits cancer cell proliferation and multiple angiogenic activities of HB-EGF.

PubMed

Sato, Shuji; Drake, Andrew W; Tsuji, Isamu; Fan, Jinhong

2012-01-01

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the epidermal growth factor family and has a variety of physiological and pathological functions. Modulation of HB-EGF activity might have a therapeutic potential in the oncology area. We explored the therapeutic possibilities by characterizing the in vitro biological activity of anti-HB-EGF monoclonal antibody Y-142. EGF receptor (EGFR) ligand and species specificities of Y-142 were tested. Neutralizing activities of Y-142 against HB-EGF were evaluated in EGFR and ERBB4 signaling. Biological activities of Y-142 were assessed in cancer cell proliferation and angiogenesis assays and compared with the anti-EGFR antibody cetuximab, the HB-EGF inhibitor CRM197, and the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab. The binding epitope was determined with alanine scanning. Y-142 recognized HB-EGF as well as the EGFR ligand amphiregulin, and bound specifically to human HB-EGF, but not to rodent HB-EGF. In addition, Y-142 neutralized HB-EGF-induced phosphorylation of EGFR and ERBB4, and blocked their downstream ERK1/2 and AKT signaling. We also found that Y-142 inhibited HB-EGF-induced cancer cell proliferation, endothelial cell proliferation, tube formation, and VEGF production more effectively than cetuximab and CRM197 and that Y-142 was superior to bevacizumab in the inhibition of HB-EGF-induced tube formation. Six amino acids in the EGF-like domain were identified as the Y-142 binding epitope. Among the six amino acids, the combination of F115 and Y123 determined the amphiregulin cross-reactivity and that F115 accounted for the species selectivity. Furthermore, it was suggested that the potent neutralizing activity of Y-142 was derived from its recognition of R142 and Y123 and its high affinity to HB-EGF. Y-142 has a potent HB-EGF neutralizing activity that modulates multiple biological activities of HB-EGF including cancer cell proliferation and angiogenic

Novel potent pyridoxine-based inhibitors of AChE and BChE, structural analogs of pyridostigmine, with improved in vivo safety profile.

PubMed

Strelnik, Alexey D; Petukhov, Alexey S; Zueva, Irina V; Zobov, Vladimir V; Petrov, Konstantin A; Nikolsky, Evgeny E; Balakin, Konstantin V; Bachurin, Sergey O; Shtyrlin, Yurii G

2016-08-15

We report a novel class of carbamate-type ChE inhibitors, structural analogs of pyridostigmine. A small library of congeneric pyridoxine-based compounds was designed, synthesized and evaluated for AChE and BChE enzymes inhibition in vitro. The most active compounds have potent enzyme inhibiting activity with IC50 values in the range of 0.46-2.1μM (for AChE) and 0.59-8.1μM (for BChE), with moderate selectivity for AChE comparable with that of pyridostigmine and neostigmine. Acute toxicity studies using mice models demonstrated excellent safety profile of the obtained compounds with LD50 in the range of 22-326mg/kg, while pyridostigmine and neostigmine are much more toxic (LD50 3.3 and 0.51mg/kg, respectively). The obtained results pave the way to design of novel potent and safe cholinesterase inhibitors for symptomatic treatment of neuromuscular disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pin1 inhibition exerts potent activity against acute myeloid leukemia through blocking multiple cancer-driving pathways.

PubMed

Lian, Xiaolan; Lin, Yu-Min; Kozono, Shingo; Herbert, Megan K; Li, Xin; Yuan, Xiaohong; Guo, Jiangrui; Guo, Yafei; Tang, Min; Lin, Jia; Huang, Yiping; Wang, Bixin; Qiu, Chenxi; Tsai, Cheng-Yu; Xie, Jane; Cao, Ziang Jeff; Wu, Yong; Liu, Hekun; Zhou, Xiaozhen; Lu, Kunping; Chen, Yuanzhong

2018-05-30

, tetracycline-inducible Pin1 knockdown and slow-releasing ATRA potently inhibited tumorigenicity of U937 and HL-60 leukemia cells in xenograft mouse models. We demonstrate that Pin1 is highly overexpressed in human AML and is a promising therapeutic target to block multiple cancer-driving pathways in AML.

Extended substrate specificity and first potent irreversible inhibitor/activity-based probe design for Zika virus NS2B-NS3 protease.

PubMed

Rut, Wioletta; Zhang, Linlin; Kasperkiewicz, Paulina; Poreba, Marcin; Hilgenfeld, Rolf; Drąg, Marcin

2017-03-01

Zika virus is spread by Aedes mosquitoes and is linked to acute neurological disorders, especially to microcephaly in newborn children and Guillan-Barré Syndrome. The NS2B-NS3 protease of this virus is responsible for polyprotein processing and therefore considered an attractive drug target. In this study, we have used the Hybrid Combinatorial Substrate Library (HyCoSuL) approach to determine the substrate specificity of ZIKV NS2B-NS3 protease in the P4-P1 positions using natural and a large spectrum of unnatural amino acids. Obtained data demonstrate a high level of specificity of the S3-S1 subsites, especially for basic amino acids. However, the S4 site exhibits a very broad preference toward natural and unnatural amino acids with selected D-amino acids being favored over L enantiomers. This information was used for the design of a very potent phosphonate inhibitor/activity-based probe of ZIKV NS2B-NS3 protease. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel curcumin analogue UBS109 potently stimulates osteoblastogenesis and suppresses osteoclastogenesis: involvement in Smad activation and NF-κB inhibition.

PubMed

Yamaguchi, Masayoshi; Moore, Terry W; Sun, Aiming; Snyder, James P; Shoji, Mamoru

2012-08-01

Bone homeostasis is maintained through a balance between osteoblastic bone formation and osteoclastic bone resorption. Bone loss is induced due to decreased osteoblastic bone formation and increased osteoclastic bone resorption with various pathologic states. Osteoporosis with its accompanying decrease in bone mass is widely recognized as a major public health problem. Pharmacologic and functional food factors may play a role in the prevention of bone loss with aging. This study was undertaken to determine the effect of curcumin analogues (curcumin, EF31, ECMN909, and UBS109), which were newly synthesized, on osteoblastogenesis and osteoclastogenesis in vitro. Among these compounds, UBS109 had a unique stimulatory effect on osteoblastic differentiation and mineralization. UBS109 stimulated both basal and bone morphogenic protein-2 (BMP2)-increased Smad-luciferase activity, the Smad signaling of which is related to osteoblastogenesis. Such an effect was not seen with other compounds. Moreover, UBS109 potently suppressed tumor necrosis factor-α (TNF-α)-increased osteoblastic nuclear factor kappa B (NF-κB)-luciferase activity. In addition, EF31, ECMN909, and UBS109 had a suppressive effect on osteoclastogenesis as compared with that of curcumin. ECMN909 and UBS109 potently inhibited the receptor activator of NF-κB (RANK) ligand (RANKL)-increased preosteoclastic NF-κB-luciferase activity, in which NF-κB signaling plays a pivotal role in osteoclastogenesis. In the present study, curcumin analogue UBS109 was found to have a stimulating effect on osteoblastogenesis and a suppressive effect on osteoclastogenesis in vitro, suggesting an anabolic effect of the compound on bone mass.

Synthesis and Anticancer Activity of Epipolythiodiketopiperazine Alkaloids

PubMed Central

Boyer, Nicolas; Morrison, Karen C.; Kim, Justin; Hergenrother, Paul J.; Movassaghi, Mohammad

2013-01-01

The epipolythiodiketopiperazine (ETP) alkaloids are a highly complex class of natural products with potent anticancer activity. Herein, we report the application of a flexible and scalable synthesis, allowing the construction of dozens of ETP derivatives. The evaluation of these compounds against cancer cell lines in culture allows for the first expansive structure–activity relationship (SAR) to be defined for monomeric and dimeric ETP-containing natural products and their synthetic cognates. Many ETP derivatives demonstrate potent anticancer activity across a broad range of cancer cell lines, and kill cancer cellsviainduction of apoptosis. Several traits thatbode well for the translational potential of the ETP class of natural products includeconcise and efficient synthetic access, potent induction of apoptotic cell death, activity against a wide range of cancer types, and a broad tolerance for modifications at multiple sitesthat should facilitate small-molecule drug development, mechanistic studies, and evaluation in vivo. PMID:23914293

Discovery and structure-activity relationships of (2-(arylthio)benzylideneamino)guanidines as a novel series of potent apoptosis inducers.

PubMed

Zhang, Han-Zhong; Crogan-Grundy, Candace; May, Chris; Drewe, John; Tseng, Ben; Cai, Sui Xiong

2009-04-01

1-(2-(2,5-Dimethoxyphenylthio)benzylidene)semicarbazide (2a) was discovered as a potent apoptosis inducer through our cell based HTS assay. SAR study led to the discovery of a more aqueous soluble analog (2-(2,5-dimethoxyphenylthio)-6-methoxybenzylideneamino)guanidine (5e) with EC(50) value of 60 nM in the caspase activation assay and GI(50) value of 62 nM in the growth inhibition assay in T47D cells. Compound 5e was found to be an inhibitor of tubulin polymerization and efficacious in a MX-1 breast tumor model.

Potent Activity of Ponatinib (AP24534) in Models of FLT3-Driven Acute Myeloid Leukemia and Other Hematologic Malignancies

PubMed Central

Gozgit, Joseph M.; Wong, Matthew J.; Wardwell, Scott; Tyner, Jeffrey W.; Loriaux, Marc M.; Mohemmad, Qurish K.; Narasimhan, Narayana I.; Shakespeare, William C.; Wang, Frank; Druker, Brian J.; Clackson, Tim; Rivera, Victor M.

2011-01-01

Ponatinib (AP24534) is a novel multitargeted kinase inhibitor that potently inhibits native and mutant BCR-ABL at clinically achievable drug levels. Ponatinib also has in vitro inhibitory activity against a discrete set of kinases implicated in the pathogenesis of other hematologic malignancies, including FLT3, KIT, fibroblast growth factor receptor 1 (FGFR1), and platelet derived growth factor receptor α (PDGFRα). Here, using leukemic cell lines containing activated forms of each of these receptors, we show that ponatinib potently inhibits receptor phosphorylation and cellular proliferation with IC50 values comparable to those required for inhibition of BCR-ABL (0.3 to 20 nmol/L). The activity of ponatinib against the FLT3-ITD mutant, found in up to 30% of acute myeloid leukemia (AML) patients, was particularly notable. In MV4-11 (FLT3-ITD+/+) but not RS4;11 (FLT3-ITD−/−) AML cells, ponatinib inhibited FLT3 signaling and induced apoptosis at concentrations of less than 10 nmol/L. In an MV4-11 mouse xenograft model, once daily oral dosing of ponatinib led to a dose-dependent inhibition of signaling and tumor regression. Ponatinib inhibited viability of primary leukemic blasts from a FLT3-ITD positive AML patient (IC50 4 nmol/L) but not those isolated from 3 patients with AML expressing native FLT3. Overall, these results support the investigation of ponatinib in patients with FLT3-ITD–driven AML and other hematologic malignancies driven by KIT, FGFR1, or PDGFRα. PMID:21482694

Identification of 2,3-diaryl-pyrazolo[1,5-b]pyridazines as potent and selective cyclooxygenase-2 inhibitors.

PubMed

Beswick, Paul; Bingham, Sharon; Bountra, Chas; Brown, Terry; Browning, Kerry; Campbell, Ian; Chessell, Iain; Clayton, Nick; Collins, Sue; Corfield, John; Guntrip, Stephen; Haslam, Claudine; Lambeth, Paul; Lucas, Fiona; Mathews, Neil; Murkit, Graham; Naylor, Alan; Pegg, Neil; Pickup, Elizabeth; Player, Hazel; Price, Helen; Stevens, Alexander; Stratton, Sharon; Wiseman, Joanne

2004-11-01

GW406381 (8), currently undergoing clinical evaluation for the treatment of inflammatory pain is a member of a novel series of 2,3-diaryl-pyrazolo[1,5-b]pyridazine based cyclooxygenase-2 (COX-2) inhibitors, which have been shown to be highly potent and selective. Several examples of the series, in addition to possessing favourable pharmacokinetic profiles and analgesic activity in vivo, have also demonstrated relatively high brain penetration in the rat compared with the clinically available compounds, which may ultimately prove beneficial in the treatment of pain.

Design of potent substrate-analogue inhibitors of canine renin

NASA Technical Reports Server (NTRS)

Hui, K. Y.; Siragy, H. M.; Haber, E.

1992-01-01

Through a systematic study of structure-activity relationships, we designed potent renin inhibitors for use in dog models. In assays against dog plasma renin at neutral pH, we found that, as in previous studies of rat renin inhibitors, the structure at the P2 position appears to be important for potency. The substitution of Val for His at this position increases potency by one order of magnitude. At the P3 position, potency appears to depend on a hydrophobic side chain that does not necessarily have to be aromatic. Our results also support the approach of optimizing potency in a renin inhibitor by introducing a moiety that promotes aqueous solubility (an amino group) at the C-terminus of the substrate analogue. In the design of potent dog plasma renin inhibitors, the influence of the transition-state residue 4(S)-amino-3(S)-hydroxy-5-cyclohexylpentanoic acid (ACHPA)-commonly used as a substitute for the scissile-bond dipeptide to boost potency-is not obvious, and appears to be sequence dependent. The canine renin inhibitor Ac-paF-Pro-Phe-Val-statine-Leu-Phe-paF-NH2 (compound 15; IC50 of 1.7 nM against dog plasma renin at pH 7.4; statine, 4(S)-amino-3(S)-hydroxy-6-methylheptanoic acid; paF, para-aminophenylalanine) had a potent hypotensive effect when infused intravenously into conscious, sodium-depleted, normotensive dogs. Also, compound 15 concurrently inhibited plasma renin activity and had a profound diuretic effect.

Naphthoquinones isolated from Diospyros anisandra exhibit potent activity against pan-resistant first-line drugs Mycobacterium tuberculosis strains.

PubMed

Uc-Cachón, Andrés Humberto; Borges-Argáez, Rocío; Said-Fernández, Salvador; Vargas-Villarreal, Javier; González-Salazar, Francisco; Méndez-González, Martha; Cáceres-Farfán, Mirbella; Molina-Salinas, Gloria María

2014-02-01

The recent emergence of multidrug-resistant (MDR), extensively drug-resistant (XDR), and totally drug-resistant (TDR) Mycobacterium tuberculosis (MTB) strains have further complicated the control of tuberculosis (TB). There is an urgent need of new molecules candidates to be developed as novel, active, and less toxic anti-tuberculosis (anti-TB) drugs. Medicinal plants have been an excellent source of leads for the development of drugs, particularly as anti-infective agents. In previous studies, the non-polar extract of Diospyros anisandra showed potent anti-TB activity, and three monomeric and five dimeric naphthoquinones have been obtained. In this study, we performed bioguided chemical fractionation and the isolation of eight naphthoquinones from D. anisandra and their evaluation of anti-TB and cytotoxic activities against mammalian cells. The n-hexane crude extract from the stem bark of the plant was obtained by maceration and liquid-liquid fractionation. The isolation of naphthoquinones was carried out by chromatographic methods and identified by gas chromatography and mass spectroscopy data analysis. Anti-TB activity was evaluated against two strains of MTB (H37Rv) susceptible to all five first-line anti-TB drugs and a clinical isolate that is resistant to these medications (pan-resistant, CIBIN 99) by measuring the minimal inhibitory concentration (MIC). Cytotoxicity of naphthoquinones was estimated against two mammalian cells, Vero line and primary cultures of human peripheral blood mononuclear (PBMC) cells, and their selectivity index (SI) was determined. Plumbagin and its dimers maritinone and 3,3'-biplumbagin showed the strongest activity against both MTB strains (MIC = 1.56-3.33 μg/mL). The bioactivity of maritinone and 3,3'-biplumbagin were 32 times more potent than rifampicin against the pan-resistant strain, and both dimers showed to be non-toxic against PBMC and Vero cells. The SI of maritinone and 3,3'-biplumbagin on Vero cells was 74.34 and 194

Trifluorothymidine exhibits potent antitumor activity via the induction of DNA double-strand breaks

PubMed Central

SUZUKI, NORIHIKO; NAKAGAWA, FUMIO; NUKATSUKA, MAMORU; FUKUSHIMA, MASAKAZU

2011-01-01

TAS-102 is an oral anticancer drug composed of trifluorothymidine (TFT) and TPI (an inhibitor of thymidine phosphorylase that strongly inhibits the biodegradation of TFT). Similar to 5-fluorouracil (5FU) and 5-fluoro-2′-deoxyuridine (FdUrd), TFT also inhibits thymidylate synthase (TS), a rate-limiting enzyme of DNA biosynthesis, and is incorporated into DNA. TFT exhibits an anticancer effect on colorectal cancer cells that have acquired 5FU and/or FdUrd resistance as a result of the overexpression of TS. Therefore, we examined the mode of action of TFT-induced DNA damage after its incorporation into DNA. When HeLa cells were treated with TFT, the number of ring-open aldehyde forms at apurinic/apyrimidinic sites increased in a dose-dependent manner, although we previously reported that no detectable excisions of TFT paired to adenine were observed using uracil DNA glycosylases, thymine DNA glycosylase or methyl-CpG binding domain 4 and HeLa whole cell extracts. To investigate the functional mechanism of TFT-induced DNA damage, we measured the phosphorylation of ATR, ATM, BRCA2, chk1 and chk2 in nuclear extracts of HeLa cells after 0, 24, 48 or 72 h of exposure to an IC50 concentration of TFT, FdUrd or 5FU using Western blot analysis or an enzyme-linked immunosorbent assay (ELISA). Unlike FdUrd and 5FU, TFT resulted in an earlier phosphorylation of ATR and chk1 proteins after only 24 h of exposure, while phosphorylated ATM, BRCA2 and chk2 proteins were detected after more than 48 h of exposure to TFT. These results suggest that TFT causes single-strand breaks followed by double-strand breaks in the DNA of TFT-treated cells. TFT (as TAS-102) showed a more potent antitumor activity than oral 5FU on CO-3 colon cancer xenografts in mice, and such antitumor potency was supported by the increased number of double-strand breaks occurring after single-strand breaks in the DNA of the TFT-treated tumors. These results suggest that TFT causes single-strand breaks after its

Synthesis and structure-activity relationships of novel lincomycin derivatives. Part 4: synthesis of novel lincomycin analogs modified at the 6- and 7-positions and their potent antibacterial activities.

PubMed

Wakiyama, Yoshinari; Kumura, Ko; Umemura, Eijiro; Ueda, Kazutaka; Watanabe, Takashi; Yamada, Keiko; Okutomi, Takafumi; Ajito, Keiichi

2017-07-01

To modify lincomycin (LCM) at the C-6 and the C-7 positions, we firstly prepared various substituted proline intermediates (7, 11-15 and 17). These proline intermediates were coupled with methyl 1-thio-α-lincosamide and tetrakis-O-trimethylsilylation followed by selective deprotection of the TMS group at the 7-position gave a wide variety of key intermediates (23-27, 47 and 50). Then, we synthesized a variety of novel LCM analogs modified at the 7-position in application of the Mitsunobu reaction, an S N 2 reaction, and a Pd-catalyzed cross-coupling reaction. Compounds 34 and 35 (1'-NH derivatives) exhibited enhanced antibacterial activities against resistant pathogens with erm gene compared with the corresponding 1'-N-methyl derivatives (3 and 37). On the basis of reported SAR, we modified the 4'-position of LCM derivatives possessing a 5-(2-nitrophenyl)-1,3,4-thiadiazol-2-yl group at the C-7 position. Compound 56 showed significantly potent antibacterial activities against S. pneumoniae and S. pyogenes with erm gene, and its activities against S. pneumoniae with erm gene were improved compared with those of 34 and 57. Although we synthesized novel analogs by transformation of a C-7 substituent focusing on the 1'-demethyl framework to prepare very potent analogs 73 and 75, it was impossible to generate novel derivatives exhibiting stronger antibacterial activities against S. pneumoniae with erm gene compared with 56.

Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

NASA Astrophysics Data System (ADS)

Aziz, Marwa A.; Serya, Rabah A. T.; Lasheen, Deena S.; Abdel-Aziz, Amal Kamal; Esmat, Ahmed; Mansour, Ahmed M.; Singab, Abdel Nasser B.; Abouzid, Khaled A. M.

2016-04-01

Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a crucial role in cancer angiogenesis. In this study, a series of novel furo[2,3-d]pyrimidine and thieno[2,3-d]pyrimidine based-derivatives were designed and synthesized as VEGFR-2 inhibitors, in accordance to the structure activity relationship (SAR) studies of known type II VEGFR-2 inhibitors. The synthesized compounds were evaluated for their ability to in vitro inhibit VEGFR-2 kinase enzyme. Seven compounds (15b, 16c, 16e, 21a, 21b, 21c and 21e) demonstrated highly potent dose-related VEGFR-2 inhibition with IC50 values in nanomolar range, of which the thieno[2,3-d]pyrimidine based-derivatives (21b, 21c and 21e) exhibited IC50 values of 33.4, 47.0 and 21 nM respectively. Moreover, furo[2,3-d]pyrimidine-based derivative (15b) showed the strongest inhibition of human umbilical vein endothelial cells (HUVEC) proliferation with 99.5% inhibition at 10 μM concentration. Consistent with our in vitro findings, compounds (21b and 21e) orally administered at 5 and 10 mg/kg/day for 8 consecutive days demonstrated potent anticancer activity in Erhlich ascites carcinoma (EAC) solid tumor murine model. Such compounds blunted angiogenesis in EAC as evidenced by reduced percent microvessel via decreasing VEGFR-2 phosphorylation with subsequent induction of apoptotic machinery. Furthermore, Miles vascular permeability assay confirmed their antiangiogenic effects in vivo. Intriguingly, such compounds showed no obvious toxicity.

Green tea polyphenols as potent enhancers of glucocorticoid-induced mouse mammary tumor virus gene expression.

PubMed

Abe, I; Umehara, K; Morita, R; Nemoto, K; Degawa, M; Noguchi, H

2001-02-16

The effect of natural and synthetic galloyl esters on glucocorticoid-induced gene expression was evaluated by using rat fibroblast 3Y1 cells stably transfected with a luciferase reporter gene under the transcriptional regulation of the mouse mammary tumor virus promoter. The glucocorticoid-induced gene transcription was strongly suppressed by synthetic alkyl esters; n-dodecyl gallate showed the most potent inhibition (66% inhibition at 10 microM), which was far more potent than that of crude tannic acid. n-Octyl and n-cetyl gallate also showed good inhibition, while gallic acid itself was not so active, suggesting that the presence of hydrophobic side chain is important for the suppressive effect. On the other hand, surprisingly, green tea gallocatechins, (-)-epigallocatechin-3-O-gallate and theasinensin A, potently enhanced the promoter activity (182 and 247% activity at 1 microM, respectively). The regulation of the level of the glucocorticoid-induced gene expression by the antioxidative gallates is of great interest from a therapeutic point of view.

LYATK1 potently inhibits LPS-mediated pro-inflammatory response

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

Xi, Feng; Liu, Yuan; Wang, Xiujuan

Lipopolysaccharide (LPS)-primed monocytes/macrophages produce pro-inflammatory cytokines, which could lead to endotoxin shock. TGF-β-activated kinase1 (TAK1) activation is involved in the process. In the current study, we studied the potential effect of a selective TAK1 inhibitor, LYTAK1, on LPS-stimulated response both in vitro and in vivo. We demonstrated that LYTAK1 inhibited LPS-induced mRNA expression and production of several pro-inflammatory cytokines [interleukin 1β (IL-1β), tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6)] in RAW 264.7 macrophages. LYTAK1's activity was almost nullified with TAK1 shRNA-knockdown. Meanwhile, in both primary mouse bone marrow derived macrophages (BMDMs) and human peripheral blood mononuclear cells (PBMCs), LPS-induced pro-inflammatory cytokine productionmore » was again attenuated with LYTAK1 co-treatment. Molecularly, LYTAK1 dramatically inhibited LPS-induced TAK1-nuclear factor kappa B (NFκB) and mitogen-activated protein kinase (Erk, Jnk and p38) activation in RAW 264.7 cells, mouse BMDMs and human PBMCs. In vivo, oral administration of LYTAK1 inhibited LPS-induced activation of TAK1-NFκB-p38 in ex-vivo cultured PBMCs, and cytokine production and endotoxin shock in mice. Together, these results demonstrate that LYTAK1 inhibits LPS-induced production of several pro-inflammatory cytokines and endotoxin shock probably through blocking TAK1-regulated signalings. - Highlights: • LYTAK1 inhibits LPS-induced pro-inflammatory cytokine production in RAW 264.7 cells. • The effect by LYTAK1 is more potent than other known TAK1 inhibitors. • LYTAK1 inhibits LPS-induced cytokine production in primary macrophages/monocytes. • LYTAK1 inhibits LPS-induced TAK1-NFκB and MAPK activation in macrophages/monocytes. • LYTAK1 gavage inhibits LPS-induced endotoxin shock and cytokine production in mice.« less

Guinea pig complement potently measures vibriocidal activity of human antibodies in response to cholera vaccines.

PubMed

Kim, Kyoung Whun; Jeong, Soyoung; Ahn, Ki Bum; Yang, Jae Seung; Yun, Cheol-Heui; Han, Seung Hyun

2017-12-01

The vibriocidal assay using guinea pig complement is widely used for the evaluation of immune responses to cholera vaccines in human clinical trials. However, it is unclear why guinea pig complement has been used over human complement in the measurement of vibriocidal activity of human sera and there have not been comparison studies for the use of guinea pig complement over those from other species. Therefore, we comparatively investigated the effects of complements derived from human, guinea pig, rabbit, and sheep on vibriocidal activity. Complements from guinea pig, rabbit, and human showed concentration-dependent vibriocidal activity in the presence of quality control serum antibodies. Of these complements, guinea pig complement was the most sensitive and effective over a wide concentration range. When the vibriocidal activity of complements was measured in the absence of serum antibodies, human, sheep, and guinea pig complements showed vibriocidal activity up to 40-fold, 20-fold, and 1-fold dilution, respectively. For human pre- and post-vaccination sera, the most potent vibriocidal activity was observed when guinea pig complement was used. In addition, the highest fold-increases between pre- and post- vaccinated sera were obtained with guinea pig complement. Furthermore, human complement contained a higher amount of V. cholerae- and its lipopolysaccharide-specific antibodies than guinea pig complement. Collectively, these results suggest that guinea pig complements are suitable for vibriocidal assays due to their high sensitivity and effectiveness to human sera.

Potent inhibition by star fruit of human cytochrome P450 3A (CYP3A) activity.

PubMed

Hidaka, Muneaki; Fujita, Ken-ichi; Ogikubo, Tetsuya; Yamasaki, Keishi; Iwakiri, Tomomi; Okumura, Manabu; Kodama, Hirofumi; Arimori, Kazuhiko

2004-06-01

There has been very limited information on the capacities of tropical fruits to inhibit human cytochrome P450 3A (CYP3A) activity. Thus, the inhibitory effects of tropical fruits on midazolam 1'-hydroxylase activity of CYP3A in human liver microsomes were evaluated. Eight tropical fruits such as common papaw, dragon fruit, kiwi fruit, mango, passion fruit, pomegranate, rambutan, and star fruit were tested. We also examined the inhibition of CYP3A activity by grapefruit (white) and Valencia orange as controls. The juice of star fruit showed the most potent inhibition of CYP3A. The addition of a star fruit juice (5.0%, v/v) resulted in the almost complete inhibition of midazolam 1'-hydroxylase activity (residual activity of 0.1%). In the case of grape-fruit, the residual activity was 14.7%. The inhibition depended on the amount of fruit juice added to the incubation mixture (0.2-6.0%, v/v). The elongation of the preincubation period of a juice from star fruit (1.25 or 2.5%, v/v) with the microsomal fraction did not alter the CYP3A inhibition, suggesting that the star fruit did not contain a mechanism-based inhibitor. Thus, we discovered filtered extracts of star fruit juice to be inhibitors of human CYP3A activity in vitro.

Identification of pyrrolo[2,3-d]pyrimidines as potent HCK and FLT3-ITD dual inhibitors.

PubMed

Koda, Yasuko; Kikuzato, Ko; Mikuni, Junko; Tanaka, Akiko; Yuki, Hitomi; Honma, Teruki; Tomabechi, Yuri; Kukimoto-Niino, Mutsuko; Shirouzu, Mikako; Shirai, Fumiyuki; Koyama, Hiroo

2017-11-15

A series of novel pyrrolo[2,3-d]pyrimidines were synthesized by introducing 15 different amino acids to 7-cyclohexyl-5-(4-phenoxyphenyl)-7H-pyrrolo[2,3-d]pyrimidine-4-amine. Compounds with potent activities against HCK and FLT3-ITD were evaluated in viability studies with acute myeloid leukemia cell line MV4-11. Our structure activity relationship analyses lead to the identification of compound 31, which exhibited potent HCK and FLT3-ITD inhibition and activity against the MV4-11 cell line. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potent Adjuvant Activity of Cationic Liposome-DNA Complexes for Genital Herpes Vaccines▿

PubMed Central

Bernstein, David I.; Cardin, Rhonda D.; Bravo, Fernando J.; Strasser, Jane E.; Farley, Nicholas; Chalk, Claudia; Lay, Marla; Fairman, Jeff

2009-01-01

Development of a herpes simplex virus (HSV) vaccine is a priority because these infections are common. It appears that potent adjuvants will be required to augment the immune response to subunit HSV vaccines. Therefore, we evaluated cationic liposome-DNA complexes (CLDC) as an adjuvant in a mouse model of genital herpes. Using a whole-virus vaccine (HVAC), we showed that the addition of CLDC improved antibody responses compared to vaccine alone. Most important, CLDC increased survival, reduced symptoms, and decreased vaginal virus replication compared to vaccine alone or vaccine administered with monophosphoryl lipid A (MPL) plus trehalose dicorynomycolate (TDM) following intravaginal challenge of mice. When CLDC was added to an HSV gD2 vaccine, it increased the amount of gamma interferon that was produced from splenocytes stimulated with gD2 compared to the amount produced with gD2 alone or with MPL-alum. The addition of CLDC to the gD2 vaccine also improved the outcome following vaginal HSV type 2 challenge compared to vaccine alone and was equivalent to vaccination with an MPL-alum adjuvant. CLDC appears to be a potent adjuvant for HSV vaccines and should be evaluated further. PMID:19279167

Discovery of methylsulfonyl indazoles as potent and orally active respiratory syncytial Virus(RSV) fusion inhibitors.

PubMed

Feng, Song; Li, Chao; Chen, Dongdong; Zheng, Xiufang; Yun, Hongying; Gao, Lu; Shen, Hong C

2017-09-29

Recently we described a novel class of imidazopyridine compounds that showed exceptional anti-RSV potency in cell culture. However, unfavorable pharmacokinetic (PK) properties and glutathione (GSH) adduct liabilities impeded their further development. In a bid to address the PK and early safety concerns, a small compound library consisting of dozens of scaffold-hopping analogues was designed and synthesized for RSV CPE assay screening, which led to the identification of a new chemical starting point: methylsulfonyl indole compound 8. In this paper, we report the discovery and optimization of a series of methylsulfonyl indazoles as potent RSV fusion inhibitors. In particular, compound 47 was orally efficacious in a RSV mouse model, with 1.6 log unit viral load reduction at 25 mg/kg BID upon oral dosing. The results may have broad implications for the design of new RSV fusion inhibitors, and demonstrate the potential for developing novel therapies for RSV infection. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Discovery of imidazopyridine derivatives as highly potent respiratory syncytial virus fusion inhibitors.

PubMed

Feng, Song; Hong, Di; Wang, Baoxia; Zheng, Xiufang; Miao, Kun; Wang, Lisha; Yun, Hongying; Gao, Lu; Zhao, Shuhai; Shen, Hong C

2015-03-12

A series of imidazolepyridine derivatives were designed and synthesized according to the established docking studies. The imidazopyridine derivatives were found to have good potency and physical-chemical properties. Several highly potent compounds such as 8ji, 8jl, and 8jm were identified with single nanomolar activities. The most potent compound 8jm showed an IC50 of 3 nM, lower microsome clearance and no CYP inhibition. The profile of 8jm appeared to be superior to BMS433771, and supported further optimization.

Discovery of Imidazopyridine Derivatives as Highly Potent Respiratory Syncytial Virus Fusion Inhibitors

PubMed Central

2015-01-01

A series of imidazolepyridine derivatives were designed and synthesized according to the established docking studies. The imidazopyridine derivatives were found to have good potency and physical-chemical properties. Several highly potent compounds such as 8ji, 8jl, and 8jm were identified with single nanomolar activities. The most potent compound 8jm showed an IC50 of 3 nM, lower microsome clearance and no CYP inhibition. The profile of 8jm appeared to be superior to BMS433771, and supported further optimization. PMID:25941547

HLBT-100: a highly potent anti-cancer flavanone from Tillandsia recurvata (L.) L.

PubMed

Lowe, Henry I C; Toyang, Ngeh J; Watson, Charah T; Ayeah, Kenneth N; Bryant, Joseph

2017-01-01

The incidence and mortalities from cancers remain on the rise worldwide. Despite significant efforts to discover and develop novel anticancer agents, many cancers remain in the unmet need category. As such, efforts to discover and develop new and more effective and less toxic agents against cancer remain a top global priority. Our drug discovery approach is natural products based with a focus on plants. Tillandsia recurvata (L.) L. is one of the plants selected by our research team for further studies based on previous bioactivity findings on the anticancer activity of this plant. The plant biomass was extracted using supercritical fluid extraction technology with CO 2 as the mobile phase. Bioactivity guided isolation was achieved by use of chromatographic technics combined with anti-proliferative assays to determine the active fraction and subsequently the pure compound. Following in house screening, the identified molecule was submitted to the US National Cancer Institute for screening on the NCI60 cell line panel using standard protocols. Effect of HLBT-100 on apoptosis, caspase 3/7, cell cycle and DNA fragmentation were assessed using standard protocols. Antiangiogenic activity was carried out using the ex vivo rat aortic ring assay. A flavonoid of the flavanone class was isolated from T. recurvata (L.) L. with potent anticancer activity. The molecule was code named as HLBT-100 (also referred to as HLBT-001). The compound inhibited brain cancer (U87 MG), breast cancer (MDA-MB231), leukemia (MV4-11), melanoma (A375), and neuroblastoma (IMR-32) with IC 50 concentrations of 0.054, 0.030, 0.024, 0.003 and 0.05 µM, respectively. The molecule also exhibited broad anticancer activity in the NCI60 panel inhibiting especially hematological, colon, CNS, melanoma, ovarian, breast and prostate cancers. Twenty-three of the NCI60 cell lines were inhibited with GI 50 values <0.100 µM. In terms of potential mechanisms of action, the molecule demonstrated effect on the

Discovery of novel, high potent, ABC type PTP1B inhibitors with TCPTP selectivity and cellular activity.

PubMed

Liu, Peihong; Du, Yongli; Song, Lianhua; Shen, Jingkang; Li, Qunyi

2016-08-08

Protein tyrosine phosphatase 1B (PTP1B) as a key negative regulator of both insulin and leptin receptor pathways has been an attractive therapeutic target for the treatment of type 2 diabetes mellitus (T2DM) and obesity. With the goal of enhancing potency and selectivity of the PTP1B inhibitors, a series of methyl salicylate derivatives as ABC type PTP1B inhibitors (P1-P7) were discovered. More importantly, compound P6 exhibited high potent inhibitory activity (IC50 = 50 nM) for PTP1B with 15-fold selectivity over T-cell PTPase (TCPTP). Further studies on cellular activities revealed that compound P6 could enhance insulin-mediated insulin receptor β (IRβ) phosphorylation and insulin-stimulated glucose uptake. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Trisubstituted Thieno[3,2-b]pyrrole 5-Carboxamides as Potent Inhibitors of Alphaviruses.

PubMed

Ching, Kuan-Chieh; Kam, Yiu-Wing; Merits, Andres; Ng, Lisa F P; Chai, Christina L L

2015-12-10

Chikungunya virus (CHIKV) is a re-emerging vector-borne alphavirus and is transmitted to humans by Aedes mosquitoes. Despite the re-emergence of CHIKV as an epidemic threat, there is no approved effective antiviral treatment currently available for CHIKV. Herein, we report the synthesis and structure-activity relationship studies of a class of thieno[3,2-b]pyrroles and the discovery of a trisubstituted thieno[3,2-b]pyrrole 5-carboxamide 15c that exhibits potent inhibitory activity against in vitro CHIKV infection. Compound 15c displayed low micromolar activity (EC50 value of ca. 2 μM) and limited cytotoxic liability (CC50 > 100 μM) therefore furnishing a selectivity index of greater than 32. Notably, 15c not only controlled viral RNA production, but efficiently inhibited the expression of CHIKV nsP1, nsP3, capsid, and E2 proteins at a concentration as low as 2.5 μM. More importantly, 15c also demonstrated broad spectrum antiviral activity against other clinically important alphaviruses such as O'nyong-nyong virus and Sindbis virus.

Development of potent ALK inhibitor and its molecular inhibitory mechanism against NSCLC harboring EML4-ALK proteins

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

Kang, Chung Hyo; College of Pharmacy, Chungnam National University, Daejeon; Yun, Jeong In

2015-08-28

Here, we show the newly synthesized and potent ALK inhibitor having similar scaffold to KRCA-0008, which was reported previously, and its molecular mechanism against cancer cells harboring EML4-ALK fusion protein. Through ALK wild type enzyme assay, we selected two compounds, KRCA-0080 and KRCA-0087, which have trifluoromethyl instead of chloride in R2 position. We characterized these newly synthesized compounds by in vitro and in vivo assays. Enzyme assay shows that KRCA-0080 is more potent against various ALK mutants, including L1196M, G1202R, T1151-L1152insT, and C1156Y, which are seen in crizotinib-resistant patients, than KRCA-0008 is. Cell based assays demonstrate our compounds downregulate the cellular signaling,more » such as Akt and Erk, by suppressing ALK activity to inhibit the proliferation of the cells harboring EML4-ALK. Interestingly, our compounds induced strong G1/S arrest in H3122 cells leading to the apoptosis, which is proved by PARP-1 cleavage. In vivo H3122 xenograft assay, we found that KRCA-0080 shows significant reduction in tumor size compared to crizotinib and KRCA-0008 by 15–20%. Conclusively, we report a potent ALK inhibitor which shows significant in vivo efficacy as well as excellent inhibitory activity against various ALK mutants. - Highlights: • We synthesized KRCA-0008 derivatives having trifluoromethyl instead of chloride. • KRCA-0080 shows superior activity against several ALK mutants to KRCA-0008. • Cellular assays show our ALK inhibitors suppress only EML4-ALK positive cells. • Our ALK inhibitors induce G1/S arrest to lead apoptosis in H3122 cells. • KRCA-0080 has superior in vivo efficacy to crizotinib and KRCA-0008 by 15–20%.« less

Bacterial flagellin—a potent immunomodulatory agent

PubMed Central

Hajam, Irshad A; Dar, Pervaiz A; Shahnawaz, Imam; Jaume, Juan Carlos; Lee, John Hwa

2017-01-01

Flagellin is a subunit protein of the flagellum, a whip-like appendage that enables bacterial motility. Traditionally, flagellin was viewed as a virulence factor that contributes to the adhesion and invasion of host cells, but now it has emerged as a potent immune activator, shaping both the innate and adaptive arms of immunity during microbial infections. In this review, we summarize our understanding of bacterial flagellin and host immune system interactions and the role flagellin as an adjuvant, anti-tumor and radioprotective agent, and we address important areas of future research interests. PMID:28860663

Anti-myeloma activity of a multi targeted kinase inhibitor, AT9283, via potent Aurora Kinase and STAT3 inhibition either alone or in combination with lenalidomide

PubMed Central

Santo, Loredana; Hideshima, Teru; Cirstea, Diana; Bandi, Madhavi; Nelson, Erik A.; Gorgun, Gullu; Rodig, Scott; Vallet, Sonia; Pozzi, Samantha; Patel, Kishan; Unitt, Christine; Squires, Matt; Hu, Yiguo; Chauhan, Dharminder; Mahindra, Anuj; Munshi, Nikhil C.; Anderson, Kenneth C.; Raje, Noopur

2014-01-01

Purpose Aurora Kinases, whose expression is linked to genetic instability and cellular proliferation, are under investigation as novel therapeutic targets in multiple myeloma (MM). Here, we investigated the preclinical activity of a small molecule–multi-targeted kinase inhibitor, AT9283, with potent activity against Aurora kinase A (AURKA), Aurora kinase B (AURKB) and Janus Kinase 2/3. Experimental design We evaluated the in vitro anti myeloma activity of AT9283 alone and in combination with lenalidomide and the in vivo efficacy by using a Xenograft mouse model of human MM. Results Our data demonstrated AT9283 induced cell growth inhibition and apoptosis in MM. Studying the apoptosis mechanism of AT9283 in MM, we observed features consistent with both AURKA and AURKB inhibition, e.g increase of cells with polyploid DNA content, decrease in phospho-Histone H3, and decrease of phospho-Aurora A. Importantly, AT9283 also inhibited STAT3 tyrosine phosphorylation in MM cells. Genetic depletion of STAT3, AURKA or AURKB showed growth inhibition of MM cells, suggesting a role of AT9283-induced inhibition of these molecules in the underlying mechanism of MM cell death. In vivo studies demonstrated decreased MM cell growth and prolonged survival in AT9283-treated mice compared to controls. Importantly, combination studies of AT9283 with lenalidomide showed significant synergistic cytotoxicity in MM cells, even in the presence of bone marrow stromal cells (BMSCs). Enhanced cytotoxicity was associated with increased inhibition of pSTAT3 and pERK. Conclusions Demonstration of in vitro and in vivo anti-MM activity of AT9283 provides the rationale for the clinical evaluation of AT9283 as monotherapy and in combination in patients with MM. PMID:21430070

Irreversible dual inhibitory mode: the novel Btk inhibitor PLS-123 demonstrates promising anti-tumor activity in human B-cell lymphoma.

PubMed

Ding, Ning; Li, Xitao; Shi, Yunfei; Ping, Lingyan; Wu, Lina; Fu, Kai; Feng, Lixia; Zheng, Xiaohui; Song, Yuqin; Pan, Zhengying; Zhu, Jun

2015-06-20

The B-cell receptor (BCR) signaling pathway has gained significant attention as a therapeutic target in B-cell malignancies. Recently, several drugs that target the BCR signaling pathway, especially the Btk inhibitor ibrutinib, have demonstrated notable therapeutic effects in relapsed/refractory patients, which indicates that pharmacological inhibition of BCR pathway holds promise in B-cell lymphoma treatment. Here we present a novel covalent irreversible Btk inhibitor PLS-123 with more potent anti-proliferative activity compared with ibrutinib in multiple cellular and in vivo models through effective apoptosis induction and dual-action inhibitory mode of Btk activation. The phosphorylation of BCR downstream activating AKT/mTOR and MAPK signal pathways was also more significantly reduced after treatment with PLS-123 than ibrutinib. Gene expression profile analysis further suggested that the different selectivity profile of PLS-123 led to significant downregulation of oncogenic gene PTPN11 expression, which might also offer new opportunities beyond what ibrutinib has achieved. In addition, PLS-123 dose-dependently attenuated BCR- and chemokine-mediated lymphoma cell adhesion and migration. Taken together, Btk inhibitor PLS-123 suggested a new direction to pharmacologically modulate Btk function and develop novel therapeutic drug for B-cell lymphoma treatment.

Irreversible dual inhibitory mode: the novel Btk inhibitor PLS-123 demonstrates promising anti-tumor activity in human B-cell lymphoma

PubMed Central

Ding, Ning; Li, Xitao; Shi, Yunfei; Ping, Lingyan; Wu, Lina; Fu, Kai; Feng, Lixia; Zheng, Xiaohui; Song, Yuqin; Pan, Zhengying; Zhu, Jun

2015-01-01

The B-cell receptor (BCR) signaling pathway has gained significant attention as a therapeutic target in B-cell malignancies. Recently, several drugs that target the BCR signaling pathway, especially the Btk inhibitor ibrutinib, have demonstrated notable therapeutic effects in relapsed/refractory patients, which indicates that pharmacological inhibition of BCR pathway holds promise in B-cell lymphoma treatment. Here we present a novel covalent irreversible Btk inhibitor PLS-123 with more potent anti-proliferative activity compared with ibrutinib in multiple cellular and in vivo models through effective apoptosis induction and dual-action inhibitory mode of Btk activation. The phosphorylation of BCR downstream activating AKT/mTOR and MAPK signal pathways was also more significantly reduced after treatment with PLS-123 than ibrutinib. Gene expression profile analysis further suggested that the different selectivity profile of PLS-123 led to significant downregulation of oncogenic gene PTPN11 expression, which might also offer new opportunities beyond what ibrutinib has achieved. In addition, PLS-123 dose-dependently attenuated BCR- and chemokine-mediated lymphoma cell adhesion and migration. Taken together, Btk inhibitor PLS-123 suggested a new direction to pharmacologically modulate Btk function and develop novel therapeutic drug for B-cell lymphoma treatment. PMID:25944695

Discovery of Indeno[1,2-c]quinoline Derivatives as Potent Dual Antituberculosis and Anti-Inflammatory Agents.

PubMed

Tseng, Chih-Hua; Tung, Chun-Wei; Wu, Chen-Hsin; Tzeng, Cherng-Chyi; Chen, Yen-Hsu; Hwang, Tsong-Long; Chen, Yeh-Long

2017-06-16

A series of indeno[1,2- c ]quinoline derivatives were designed, synthesized and evaluated for their anti-tuberculosis (anti-TB) and anti-inflammatory activities. The minimum inhibitory concentration (MIC) of the newly synthesized compound was tested against Mycobacterium tuberculosis H 37 R V . Among the tested compounds, ( E )- N '-[6-(4-hydroxypiperidin-1-yl)-11 H -indeno[1,2- c ]quinolin-11-ylidene]isonicotino-hydrazide ( 12 ), exhibited significant activities against the growth of M. tuberculosis (MIC values of 0.96 μg/mL) with a potency approximately equal to that of isoniazid (INH), an anti-TB drug. Important structure features were analyzed by quantitative structure-activity relationship (QSAR) analysis to give better insights into the structure determinants for predicting the anti-TB activity. The anti-inflammatory activity was induced by superoxide anion generation and neutrophil elastase (NE) release using the formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLF)-activated human neutrophils method. Results indicated that compound 12 demonstrated a potent dual inhibitory effect on NE release and superoxide anion generation with IC 50 values of 1.76 and 1.72 μM, respectively. Our results indicated that compound 12 is a potential lead compound for the discovery of dual anti-TB and anti-inflammatory drug candidates. In addition, 6-[3-(hydroxymethyl)piperidin-1-yl]-9-methoxy-11 H -indeno[1,2- c ]quinolin-11-one ( 4g ) showed a potent dual inhibitory effect on NE release and superoxide anion generation with IC 50 values of 0.46 and 0.68 μM, respectively, and is a potential lead compound for the discovery of anti-inflammatory drug candidates.

Structure-activity relationship for enantiomers of potent inhibitors of B. anthracis dihydrofolate reductase

PubMed Central

Bourne, Christina R.; Wakeham, Nancy; Nammalwar, Baskar; Tseitin, Vladimir; Bourne, Philip C.; Barrow, Esther W.; Mylvaganam, Shankari; Ramnarayan, Kal; Bunce, Richard A.; Berlin, K. Darrell; Barrow, William W.

2012-01-01

Background Bacterial resistance to antibiotic therapies is increasing and new treatment options are badly needed. There is an overlap between these resistant bacteria and organisms classified as likely bioterror weapons. For example, Bacillus anthracis is innately resistant to the anti-folate trimethoprim due to sequence changes found in the dihydrofolate reductase enzyme. Development of new inhibitors provides an opportunity to enhance the current arsenal of anti-folate antibiotics while also expanding the coverage of the anti-folate class. Methods We have characterized inhibitors of Bacillus anthracis dihydrofolate reductase by measuring the Ki and MIC values and calculating the energetics of binding. This series contains a core diaminopyrimidine ring, a central dimethoxybenzyl ring, and a dihydrophthalazine moiety. We have altered the chemical groups extended from a chiral center on the dihydropyridazine ring of the phthalazine moiety. The interactions for the most potent compounds were visualized by X-ray structure determination. Results We find that the potency of individual enantiomers is divergent with clear preference for the S-enantiomer, while maintaining a high conservation of contacts within the binding site. The preference for enantiomers seems to be predicated largely by differential interactions with protein residues Leu29, Gln30 and Arg53. Conclusions These studies have clarified the activity of modifications and of individual enantiomers, and highlighted the role of the less-active R-enantiomer in effectively diluting the more active S-enantiomer in racemic solutions. This directly contributes to the development of new antimicrobials, combating trimethoprim resistance, and treatment options for potential bioterrorism agents. PMID:22999981

2-Arylbenzo[b]furan derivatives as potent human lipoxygenase inhibitors.

PubMed

Lang, Li; Dong, Ningning; Wu, Deyan; Yao, Xue; Lu, Weiqiang; Zhang, Chen; Ouyang, Ping; Zhu, Jin; Tang, Yun; Wang, Wei; Li, Jian; Huang, Jin

2016-01-01

Human lipoxygenases (LOXs) have been emerging as effective therapeutic targets for inflammatory diseases. In this study, we found that four natural 2-arylbenzo[b]furan derivatives isolated from Artocarpus heterophyllus exhibited potent inhibitory activities against human LOXs, including moracin C (1), artoindonesianin B-1 (2), moracin D (3), moracin M (4). In our in vitro experiments, compound 1 was identified as the most potent LOX inhibitor and the moderate subtype selective inhibitor of 12-LOX. Compounds 1 and 2 act as competitive inhibitors of LOXs. Moreover, 1 significantly inhibits LTB4 production and chemotactic capacity of neutrophils, and is capable of protecting vascular barrier from plasma leakage in vivo. In addition, the preliminary structure-activity relationship analysis was performed based on the above four naturally occurring (1-4) and six additional synthetic 2-arylbenzo[b]furan derivatives. Taken together, these 2-arylbenzo[b]furan derivatives, as LOXs inhibitors, could represent valuable leads for the future development of therapeutic agents for inflammatory diseases.

Design of potent and selective human cathepsin K inhibitors that span the active site

PubMed Central

Thompson, Scott K.; Halbert, Stacie M.; Bossard, Mary J.; Tomaszek, Thaddeus A.; Levy, Mark A.; Zhao, Baoguang; Smith, Ward W.; Abdel-Meguid, Sherin S.; Janson, Cheryl A.; D’Alessio, Karla J.; McQueney, Michael S.; Amegadzie, Bernard Y.; Hanning, Charles R.; DesJarlais, Renee L.; Briand, Jacques; Sarkar, Susanta K.; Huddleston, Michael J.; Ijames, Carl F.; Carr, Steven A.; Garnes, Keith T.; Shu, Art; Heys, J. Richard; Bradbeer, Jeremy; Zembryki, Denise; Lee-Rykaczewski, Liz; James, Ian E.; Lark, Michael W.; Drake, Fred H.; Gowen, Maxine; Gleason, John G.; Veber, Daniel F.

1997-01-01

Potent and selective active-site-spanning inhibitors have been designed for cathepsin K, a cysteine protease unique to osteoclasts. They act by mechanisms that involve tight binding intermediates, potentially on a hydrolytic pathway. X-ray crystallographic, MS, NMR spectroscopic, and kinetic studies of the mechanisms of inhibition indicate that different intermediates or transition states are being represented that are dependent on the conditions of measurement and the specific groups flanking the carbonyl in the inhibitor. The species observed crystallographically are most consistent with tetrahedral intermediates that may be close approximations of those that occur during substrate hydrolysis. Initial kinetic studies suggest the possibility of irreversible and reversible active-site modification. Representative inhibitors have demonstrated antiresorptive activity both in vitro and in vivo and therefore are promising leads for therapeutic agents for the treatment of osteoporosis. Expansion of these inhibitor concepts can be envisioned for the many other cysteine proteases implicated for therapeutic intervention. PMID:9405598

Highly potent fibrinolytic serine protease from Streptomyces.

PubMed

Uesugi, Yoshiko; Usuki, Hirokazu; Iwabuchi, Masaki; Hatanaka, Tadashi

2011-01-05

We introduce a highly potent fibrinolytic serine protease from Streptomyces omiyaensis (SOT), which belongs to the trypsin family. The fibrinolytic activity of SOT was examined using in vitro assays and was compared with those of known fibrinolytic enzymes such as plasmin, tissue-type plasminogen activator (t-PA), urokinase, and nattokinase. Compared to other enzymes, SOT showed remarkably higher hydrolytic activity toward mimic peptides of fibrin and plasminogen. The fibrinolytic activity of SOT is about 18-fold higher than that of plasmin, and is comparable to that of t-PA by fibrin plate assays. Furthermore, SOT had some plasminogen activator-like activity. Results show that SOT and nattokinase have very different fibrinolytic and fibrinogenolytic modes, engendering significant synergetic effects of SOT and nattokinase on fibrinolysis. These results suggest that SOT presents important possibilities for application in the therapy of thrombosis. Copyright © 2010 Elsevier Inc. All rights reserved.

An Enterotoxin-Like Binary Protein from Pseudomonas protegens with Potent Nematicidal Activity.

PubMed

Wei, Jun-Zhi; Siehl, Daniel L; Hou, Zhenglin; Rosen, Barbara; Oral, Jarred; Taylor, Christopher G; Wu, Gusui

2017-10-01

Soil microbes are a major food source for free-living soil nematodes. It is known that certain soil bacteria have evolved systems to combat predation. We identified the nematode-antagonistic Pseudomonas protegens strain 15G2 from screening of microbes. Through protein purification we identified a binary protein, designated Pp-ANP, which is responsible for the nematicidal activity. This binary protein inhibits Caenorhabditis elegans growth and development by arresting larvae at the L1 stage and killing older-staged worms. The two subunits, Pp-ANP1a and Pp-ANP2a, are active when reconstituted from separate expression in Escherichia coli The binary toxin also shows strong nematicidal activity against three other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and Acrobeloides sp.), but we did not find any activity against insects and fungi under test conditions, indicating specificity for nematodes. Pp-ANP1a has no significant identity to any known proteins, while Pp-ANP2a shows ∼30% identity to E. coli heat-labile enterotoxin (LT) subunit A and cholera toxin (CT) subunit A. Protein modeling indicates that Pp-ANP2a is structurally similar to CT/LT and likely acts as an ADP-ribosyltransferase. Despite the similarity, Pp-ANP shows several characteristics distinct from CT/LT toxins. Our results indicate that Pp-ANP is a new enterotoxin-like binary toxin with potent and specific activity to nematodes. The potency and specificity of Pp-ANP suggest applications in controlling parasitic nematodes and open an avenue for further research on its mechanism of action and role in bacterium-nematode interaction. IMPORTANCE This study reports the discovery of a new enterotoxin-like binary protein, Pp-ANP, from a Pseudomonas protegens strain. Pp-ANP shows strong nematicidal activity against Caenorhabditis elegans larvae and older-staged worms. It also shows strong activity on other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and

Central domain of IL-33 is cleaved by mast cell proteases for potent activation of group-2 innate lymphoid cells

PubMed Central

Lefrançais, Emma; Duval, Anais; Mirey, Emilie; Roga, Stéphane; Espinosa, Eric; Cayrol, Corinne; Girard, Jean-Philippe

2014-01-01

Interleukin-33 (IL-33) is an alarmin cytokine from the IL-1 family. IL-33 activates many immune cell types expressing the interleukin 1 receptor-like 1 (IL1RL1) receptor ST2, including group-2 innate lymphoid cells (ILC2s, natural helper cells, nuocytes), the major producers of IL-5 and IL-13 during type-2 innate immune responses and allergic airway inflammation. IL-33 is likely to play a critical role in asthma because the IL33 and ST2/IL1RL1 genes have been reproducibly identified as major susceptibility loci in large-scale genome-wide association studies. A better understanding of the mechanisms regulating IL-33 activity is thus urgently needed. Here, we investigated the role of mast cells, critical effector cells in allergic disorders, known to interact with ILC2s in vivo. We found that serine proteases secreted by activated mast cells (chymase and tryptase) generate mature forms of IL-33 with potent activity on ILC2s. The major forms produced by mast cell proteases, IL-3395–270, IL-33107–270, and IL-33109–270, were 30-fold more potent than full-length human IL-331–270 for activation of ILC2s ex vivo. They induced a strong expansion of ILC2s and eosinophils in vivo, associated with elevated concentrations of IL-5 and IL-13. Murine IL-33 is also cleaved by mast cell tryptase, and a tryptase inhibitor reduced IL-33–dependent allergic airway inflammation in vivo. Our study identifies the central cleavage/activation domain of IL-33 (amino acids 66–111) as an important functional domain of the protein and suggests that interference with IL-33 cleavage and activation by mast cell and other inflammatory proteases could be useful to reduce IL-33–mediated responses in allergic asthma and other inflammatory diseases. PMID:25313073

Atpenins, potent and specific inhibitors of mitochondrial complex II (succinate-ubiquinone oxidoreductase)

PubMed Central

Miyadera, Hiroko; Shiomi, Kazuro; Ui, Hideaki; Yamaguchi, Yuichi; Masuma, Rokuro; Tomoda, Hiroshi; Miyoshi, Hideto; Osanai, Arihiro; Kita, Kiyoshi; Ōmura, Satoshi

2003-01-01

Enzymes in the mitochondrial respiratory chain are involved in various physiological events in addition to their essential role in the production of ATP by oxidative phosphorylation. The use of specific and potent inhibitors of complex I (NADH-ubiquinone reductase) and complex III (ubiquinol-cytochrome c reductase), such as rotenone and antimycin, respectively, has allowed determination of the role of these enzymes in physiological processes. However, unlike complexes I, III, and IV (cytochrome c oxidase), there are few potent and specific inhibitors of complex II (succinate-ubiquinone reductase) that have been described. In this article, we report that atpenins potently and specifically inhibit the succinate-ubiquinone reductase activity of mitochondrial complex II. Therefore, atpenins may be useful tools for clarifying the biochemical and structural properties of complex II, as well as for determining its physiological roles in mammalian tissues. PMID:12515859

Identification of potent maturation inhibitors against HIV-1 clade C.

PubMed

Timilsina, Uddhav; Ghimire, Dibya; Timalsina, Bivek; Nitz, Theodore J; Wild, Carl T; Freed, Eric O; Gaur, Ritu

2016-06-06

Antiretroviral therapy has led to a profound improvement in the clinical care of HIV-infected patients. However, drug tolerability and the evolution of drug resistance have limited treatment options for many patients. Maturation inhibitors are a new class of antiretroviral agents for treatment of HIV-1. They act by interfering with the maturation of the virus by blocking the last step in Gag processing: the cleavage of the capsid-spacer peptide 1 (CA-SP1) intermediate to mature CA by the viral protease (PR). The first-in-class maturation inhibitor bevirimat (BVM) failed against a subset of HIV-1 isolates in clinical trials due to polymorphisms present in the CA-SP1 region of the Gag protein. Sequence analysis indicated that these polymorphisms are more common in non-clade B strains of HIV-1 such as HIV-1 clade C. Indeed, BVM was found to be ineffective against HIV-1 clade C molecular clones tested in this study. A number of BVM analogs were synthesized by chemical modifications at the C-28 position to improve its activity. The new BVM analogs displayed potent activity against HIV-1 clade B and C and also reduced infectivity of the virus. This study identifies novel and broadly active BVM analogs that may ultimately demonstrate efficacy in the clinic.

O-(Triazolyl)methyl carbamates as a novel and potent class of FAAH inhibitors

PubMed Central

Colombano, Giampiero; Albani, Clara; Ottonello, Giuliana; Ribeiro, Alison; Scarpelli, Rita; Tarozzo, Glauco; Daglian, Jennifer; Jung, Kwang-Mook; Piomelli, Daniele; Bandiera, Tiziano

2015-01-01

Inhibition of fatty acid amide hydrolase (FAAH) activity is under investigation as a valuable strategy for the treatment of several disorders, including pain and drug addiction. A number of potent FAAH inhibitors belonging to different chemical classes have been disclosed. O-aryl carbamates are one of the most representative families. In the search for novel FAAH inhibitors, we synthesized a series of O-(1,2,3-triazol-4-yl)methyl carbamate derivatives exploiting the copper-catalyzed [3 + 2] cycloaddition reaction between azides and alkynes (click chemistry). We explored structure-activity relationships within this new class of compounds and identified potent inhibitors of both rat and human FAAH with IC50 values in the single-digit nanomolar range. PMID:25338703

Maraviroc (UK-427,857), a Potent, Orally Bioavailable, and Selective Small-Molecule Inhibitor of Chemokine Receptor CCR5 with Broad-Spectrum Anti-Human Immunodeficiency Virus Type 1 Activity

PubMed Central

Dorr, Patrick; Westby, Mike; Dobbs, Susan; Griffin, Paul; Irvine, Becky; Macartney, Malcolm; Mori, Julie; Rickett, Graham; Smith-Burchnell, Caroline; Napier, Carolyn; Webster, Rob; Armour, Duncan; Price, David; Stammen, Blanda; Wood, Anthony; Perros, Manos

2005-01-01

Maraviroc (UK-427,857) is a selective CCR5 antagonist with potent anti-human immunodeficiency virus type 1 (HIV-1) activity and favorable pharmacological properties. Maraviroc is the product of a medicinal chemistry effort initiated following identification of an imidazopyridine CCR5 ligand from a high-throughput screen of the Pfizer compound file. Maraviroc demonstrated potent antiviral activity against all CCR5-tropic HIV-1 viruses tested, including 43 primary isolates from various clades and diverse geographic origin (geometric mean 90% inhibitory concentration of 2.0 nM). Maraviroc was active against 200 clinically derived HIV-1 envelope-recombinant pseudoviruses, 100 of which were derived from viruses resistant to existing drug classes. There was little difference in the sensitivity of the 200 viruses to maraviroc, as illustrated by the biological cutoff in this assay (= geometric mean plus two standard deviations [SD] of 1.7-fold). The mechanism of action of maraviroc was established using cell-based assays, where it blocked binding of viral envelope, gp120, to CCR5 to prevent the membrane fusion events necessary for viral entry. Maraviroc did not affect CCR5 cell surface levels or associated intracellular signaling, confirming it as a functional antagonist of CCR5. Maraviroc has no detectable in vitro cytotoxicity and is highly selective for CCR5, as confirmed against a wide range of receptors and enzymes, including the hERG ion channel (50% inhibitory concentration, >10 μM), indicating potential for an excellent clinical safety profile. Studies in preclinical in vitro and in vivo models predicted maraviroc to have human pharmacokinetics consistent with once- or twice-daily dosing following oral administration. Clinical trials are ongoing to further investigate the potential of using maraviroc for the treatment of HIV-1 infection and AIDS. PMID:16251317

A new protoberberine alkaloid from Meconopsis simplicifolia (D. Don) Walpers with potent antimalarial activity against a multidrug resistant Plasmodium falciparum strain.

PubMed

Wangchuk, Phurpa; Phurpa, Wangchuk; Keller, Paul A; Pyne, Stephen G; Lie, Wilford; Willis, Anthony C; Rattanajak, Roonglawan; Kamchonwongpaisan, Sumalee

2013-12-12

The aerial components of Meconopsis simplicifolia (D. Don) Walpers are indicated in Bhutanese traditional medicine for treating malaria, coughs and colds, and the infections of the liver, lung and blood. This study is to validate the ethnopharmacological uses of this plant and also identify potent antimalarial drug leads through bioassays of its crude extracts and phytochemical constituents. Meconopsis simplicifolia (D. Don) Walpers was collected from Bhutan and its crude MeOH extract was subjected to acid-base fractionation. Through repeated extractions, separations and spectroscopic analysis, the alkaloids obtained were identified and tested for their antimalarial and cytotoxicity activities. Phytochemical studies resulted in the isolation of one new protoberberine type alkaloid which we named as simplicifolianine and five known alkaloids: protopine, norsanguinarine, dihydrosanguinarine, 6-methoxydihydrosanguinarine and oxysanguinarine. Among the five of the alkaloids tested, simplicifolianine showed the most potent antiplasmodial activities against the Plasmodium falciparum strains, TM4/8.2 (chloroquine-antifolate sensitive strain) and K1CB1 (multidrug resistant strain) with IC50 values of 0.78 μg/mL and 1.29 μg/mL, respectively. The compounds tested did not show any significant cytotoxicity activities against human oral carcinoma KB cells and normal Vero cells of African kidney epithelial cells. This study validated the traditional uses of the plant for the treatment of malaria and identified a new alkaloid, simplicifolianine as a potential antimalarial drug lead. © 2013 Published by Elsevier Ireland Ltd.

Investigation of 20S-hydroxyvitamin D3 analogs and their 1α-OH derivatives as potent vitamin D receptor agonists with anti-inflammatory activities.

PubMed

Lin, Zongtao; Marepally, Srinivasa R; Goh, Emily S Y; Cheng, Chloe Y S; Janjetovic, Zorica; Kim, Tae-Kang; Miller, Duane D; Postlethwaite, Arnold E; Slominski, Andrzej T; Tuckey, Robert C; Peluso-Iltis, Carole; Rochel, Natacha; Li, Wei

2018-01-24

20S-hydroxyvitamin D 3 [20S(OH)D 3 ] is anti-inflammatory and not hypercalcemic, suggesting its potential as a lead compound. In this study, side chain modified 20S(OH)D 3 analogs (4, 13, 23 and 33) together with their 1α-OH derivatives were synthesized and their metabolism and biological activities tested. 4, 13 and 23 are good substrates for CYP27B1, enabling enzymatic synthesis of their 1α-OH derivatives 5, 14 and 24. However, 33 could not be hydroxylated by CYP27B1 and acts as an inhibitor. All analogs were poorer substrates for CYP24A1 than calcitriol, indicating improved catabolic stability. While the parent analogs showed minimal VDR stimulating activity, their 1α-OH derivatives were potent VDR agonists. 4, 5, 14 and 24 significantly upregulated the expression of CYP24A1 at the mRNA level, consistent with their VDR activation abilities and indicating that 1α-hydroxylation is required to produce analogs with strong activity. These analogs have anti-inflammatory activities that are influenced by side chain composition and by 1α-hydroxylation. To understand their molecular interactions with the VDR, 20S(OH)D 3 , 4 and 33 were co-crystalized with the VDR ligand binding domain, which revealed subtle differences to the calcitriol-bound receptor. This study demonstrates the potential of the 20S(OH)D 3 scaffold for the development of novel anti-inflammatory agents.

Forging a potent vaccine adjuvant: CpG ODN/cationic peptide nanorings.

PubMed

Gungor, Bilgi; Yagci, Fuat Cem; Gursel, Ihsan; Gursel, Mayda

Type I interferon inducers may potentially be engineered to function as antiviral and anticancer agents, or alternatively, vaccine adjuvants, all of which may have clinical applications. We recently described a simple strategy to convert a Toll-like receptor 9 (TLR9) agonist devoid of interferon α (IFNα) stimulating activity into a robust Type I interferon inducer with potent vaccine adjuvant activity.

The Importance of Engaging Pupils Actively in Demonstrations

ERIC Educational Resources Information Center

Suomela, Liisa; Juuti, Kalle; Ahtee, Maija

2013-01-01

Demonstrating is a traditional method in teaching science that can raise interest and encourage pupils to think about a topic. While demonstrating, the teacher can focus the pupils' attention on the relevant facts and introduce scientific principles and concepts. Through discussion and actively making observations and inferences, rather than…

Pharmacokinetics and pharmacodynamics of orally administered acetylenic tricyclic bis(cyanoenone), a highly potent Nrf2 activator with a reversible covalent mode of action

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

Kostov, Rumen V.; Knatko, Elena V.; McLaughlin, Lesley A.

The acetylenic tricyclic bis(cyanoenone) TBE-31 is a highly potent cysteine targeting compound with a reversible covalent mode of action; its best-characterized target being Kelch-like ECH-associated protein-1 (Keap1), the cellular sensor for oxidants and electrophiles. TBE-31 reacts with cysteines of Keap1, impairing its ability to target nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) for degradation. Consequently, Nrf2 accumulates and orchestrates cytoprotective gene expression. In this study we investigated the pharmacokinetic and pharmacodynamic properties of TBE-31 in C57BL/6 mice. After a single oral dose of 10 μmol/kg (∼200 nmol/animal), the concentration of TBE-31 in blood exhibited two peaks, at 22.3 nM and at 15.5 nM, 40 minmore » and 4 h after dosing, respectively, as determined by a quantitative stable isotope dilution LC-MS/MS method. The AUC{sub 0–24h} was 195.5 h/nmol/l, the terminal elimination half-life was 10.2 h, and the k{sub el} was 0.068 h{sup −1}. To assess the pharmacodynamics of Nrf2 activation by TBE-31, we determined the enzyme activity of its prototypic target, NAD(P)H:quinone oxidoreductase 1 (NQO1) and found it elevated by 2.4- and 1.5-fold in liver and heart, respectively. Continuous feeding for 18 days with diet delivering the same daily doses of TBE-31 under conditions of concurrent treatment with the immunosuppressive agent azathioprine had a similar effect on Nrf2 activation without any indications of toxicity. Together with previous reports showing the cytoprotective effects of TBE-31 in animal models of carcinogenesis, our results demonstrate the high potency, efficacy and suitability for chronic administration of cysteine targeting reversible covalent drugs. - Highlights: • TBE-31 is a cysteine targeting compound with a reversible covalent mode of action. • After a single oral dose, the blood concentration of TBE-31 exhibits two peaks. • Oral TBE-31 is a potent activator of Nrf2-dependent enzymes

Sulfoximines as potent RORγ inverse agonists.

PubMed

Ouvry, Gilles; Bihl, Franck; Bouix-Peter, Claire; Christin, Olivier; Defoin-Platel, Claire; Deret, Sophie; Feret, Christophe; Froude, David; Hacini-Rachinel, Feriel; Harris, Craig S; Hervouet, Catherine; Lafitte, Guillaume; Luzy, Anne-Pascale; Musicki, Branislav; Orfila, Danielle; Parnet, Veronique; Pascau, Coralie; Pascau, Jonathan; Pierre, Romain; Raffin, Catherine; Rossio, Patricia; Spiesse, Delphine; Taquet, Nathalie; Thoreau, Etienne; Vatinel, Rodolphe; Vial, Emmanuel; Hennequin, Laurent F

2018-05-01

Progress in the identification of suitable RORγ inverse agonists as clinical candidates has been hampered by the high lipophilicity that seems required for high potency on this nuclear receptor. In this context, we decided to focus on the replacement of the hydroxymethyl group found on known modulators to determine if more polarity could be tolerated in this position. SAR of the replacement of this moiety is presented in this article leading to the identification of sulfoximine derivatives as potent modulators with pharmacological activity in the in vivo mouse Imiquimod psoriasis model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Structure and synthesis of a potent glutamate receptor antagonist in wasp venom.

PubMed Central

Eldefrawi, A T; Eldefrawi, M E; Konno, K; Mansour, N A; Nakanishi, K; Oltz, E; Usherwood, P N

1988-01-01

A low molecular weight toxin isolated from the venom of the digger wasp Philanthus triangulum, first noted by T. Piek, is a potent antagonist of transmission at quisqualate-sensitive glutamate synapses of locust leg muscle. This philanthotoxin 433 (PTX-433) has been purified, chemically characterized, and subsequently synthesized along with two closely related analogues. It has a butyryl/tyrosyl/spermine sequence and a molecular weight of 435. Its two analogues, PTX-343 and PTX-334 (the numerals denoting the number of methylenes between the amino groups of the spermine moiety), are also active on the glutamate synapse of the locust leg muscle; PTX-334 was more potent and PTX-343 was less potent than the natural toxin. Such chemicals are useful for studying, labeling, and purifying glutamate receptors and may become models for an additional class of therapeutic drugs and possibly insecticides. Images PMID:2838850

Structure-activity relationships of rationally designed AMACR 1A inhibitors.

PubMed

Yevglevskis, Maksims; Lee, Guat L; Nathubhai, Amit; Petrova, Yoana D; James, Tony D; Threadgill, Michael D; Woodman, Timothy J; Lloyd, Matthew D

2018-04-30

α-Methylacyl-CoA racemase (AMACR; P504S) is a promising novel drug target for prostate and other cancers. Assaying enzyme activity is difficult due to the reversibility of the 'racemisation' reaction and the difficulties in the separation of epimeric products; consequently few inhibitors have been described and no structure-activity relationship study has been performed. This paper describes the first structure-activity relationship study, in which a series of 23 known and potential rational AMACR inhibitors were evaluated. AMACR was potently inhibited (IC 50  = 400-750 nM) by ibuprofenoyl-CoA and derivatives. Potency was positively correlated with inhibitor lipophilicity. AMACR was also inhibited by straight-chain and branched-chain acyl-CoA esters, with potency positively correlating with inhibitor lipophilicity. 2-Methyldecanoyl-CoAs were ca. 3-fold more potent inhibitors than decanoyl-CoA, demonstrating the importance of the 2-methyl group for effective inhibition. Elimination substrates and compounds with modified acyl-CoA cores were also investigated, and shown to be potent inhibitors. These results are the first to demonstrate structure-activity relationships of rational AMACR inhibitors and that potency can be predicted by acyl-CoA lipophilicity. The study also demonstrates the utility of the colorimetric assay for thorough inhibitor characterisation. Copyright © 2018 Elsevier Inc. All rights reserved.

An Efficient Buchwald-Hartwig/Reductive Cyclization for the Scaffold Diversification of Halogenated Phenazines: Potent Antibacterial Targeting, Biofilm Eradication, and Prodrug Exploration.

PubMed

Garrison, Aaron T; Abouelhassan, Yasmeen; Kallifidas, Dimitris; Tan, Hao; Kim, Young S; Jin, Shouguang; Luesch, Hendrik; Huigens, Robert W

2018-05-10

Bacterial biofilms are surface-attached communities comprised of nonreplicating persister cells housed within a protective extracellular matrix. Biofilms display tolerance toward conventional antibiotics, occur in ∼80% of infections, and lead to >500000 deaths annually. We recently identified halogenated phenazine (HP) analogues which demonstrate biofilm-eradicating activities against priority pathogens; however, the synthesis of phenazines presents limitations. Herein, we report a refined HP synthesis which expedited the identification of improved biofilm-eradicating agents. 1-Methoxyphenazine scaffolds were generated through a Buchwald-Hartwig cross-coupling (70% average yield) and subsequent reductive cyclization (68% average yield), expediting the discovery of potent biofilm-eradicating HPs (e.g., 61: MRSA BAA-1707 MBEC = 4.69 μM). We also developed bacterial-selective prodrugs (reductively activated quinone-alkyloxycarbonyloxymethyl moiety) to afford HP 87, which demonstrated excellent antibacterial and biofilm eradication activities against MRSA BAA-1707 (MIC = 0.15 μM, MBEC = 12.5 μM). Furthermore, active HPs herein exhibit negligible cytotoxic or hemolytic effects, highlighting their potential to target biofilms.

Polybrominated diphenyl ethers with potent and broad spectrum antimicrobial activity from the marine sponge Dysidea.

PubMed

Sun, Shi; Canning, Corene B; Bhargava, Kanika; Sun, Xiuxiu; Zhu, Wenjun; Zhou, Ninghui; Zhang, Yifan; Zhou, Kequan

2015-01-01

Three polybrominated diphenyl ethers, 2-(2',4'-dibromophenoxy)-3,5-dibromophenol (1) and 2-(2',4'-dibromophenoxy)-3,4,5-tribromophenol (2) were isolated from the marine sponge Dysidea granulosa; and 2-(2',4'-dibromophenoxy)-4,6-dibromophenol (3) from Dysidea spp. They exhibited potent and broad spectrum in vitro antibacterial activity, especially against methicillin resistant Staphylococcus aureus (MRSA), methicillin sensitive Staphylococcus aureus (MSSA), Escherichia coli O157:H7, and Salmonella. Minimal inhibitory concentration (MIC) was evaluated against 12 clinical and standard strains of Gram positive and negative bacteria. The observed MIC range was 0.1-4.0mg/L against all the Gram positive bacteria and 0.1-16.0mg/L against Gram negative bacteria. 2-(2',4″-Dibromophenoxy)-3,5-dibromophenol showed stronger broad spectrum antibacterial activity than other two compounds. 2-(2',4″-Dibromophenoxy)-3,5-dibromophenol and 2-(2',4'-dibromophenoxy)-4,6-dibromophenol are thermo-stable. The results suggest that 2-(2',4'-dibromophenoxy)-3,5-dibromophenol could be used as a potential lead molecule for anti-MRSA, anti-E. coli O157:H7, and anti-Salmonella for drug development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stereoselective synthesis of an active metabolite of the potent PI3 kinase inhibitor PKI-179.

PubMed

Chen, Zecheng; Venkatesan, Aranapakam M; Dos Santos, Osvaldo; Delos Santos, Efren; Dehnhardt, Christoph M; Ayral-Kaloustian, Semiramis; Ashcroft, Joseph; McDonald, Leonard A; Mansour, Tarek S

2010-03-05

The synthesis and stereochemical determination of 1-(4-(4-((1R,5R,6R)-6-hydroxy-3-oxa-8-azabicyclo[3.2.1]octan-8-yl)-6-morpholino-1,3,5-triazin-2-yl)phenyl)-3-(pyridin-4-yl)urea (2), an active metabolite of the potent PI3 kinase inhibitor PKI-179 (1), is described. Stereospecific hydroboration of the double bond of 2,5-dihydro-1H-pyrrole 8 gave the 2,3-trans alcohol 9 exclusively. The configuration of the 3-hydroxyl group in 9 was inverted by an oxidation and stereoselective reduction sequence to give the corresponding 2,3-cis isomer 23. Both exo (21) and endo (27) isomers of the metabolite 2 were prepared via a practical synthetic route from 9 and 23, respectively, and the stereochemistry of 2 was determined to be endo. The endo isomer (27) was separated into two enantiomers 28 and 29 by chiral HPLC. Compound 2 was found to be enantiomerically pure and identical to the enantiomer 28. The absolute stereochemistry of the enantiomer 28 was determined by Mosher's method, thus establishing the stereochemistry of the active metabolite 2.

Fragment-based discovery of a new family of non-peptidic small-molecule cyclophilin inhibitors with potent antiviral activities

PubMed Central

Ahmed-Belkacem, Abdelhakim; Colliandre, Lionel; Ahnou, Nazim; Nevers, Quentin; Gelin, Muriel; Bessin, Yannick; Brillet, Rozenn; Cala, Olivier; Douguet, Dominique; Bourguet, William; Krimm, Isabelle; Pawlotsky, Jean-Michel; Guichou, Jean- François

2016-01-01

Cyclophilins are peptidyl-prolyl cis/trans isomerases (PPIase) that catalyse the interconversion of the peptide bond at proline residues. Several cyclophilins play a pivotal role in the life cycle of a number of viruses. The existing cyclophilin inhibitors, all derived from cyclosporine A or sanglifehrin A, have disadvantages, including their size, potential for side effects unrelated to cyclophilin inhibition and drug–drug interactions, unclear antiviral spectrum and manufacturing issues. Here we use a fragment-based drug discovery approach using nucleic magnetic resonance, X-ray crystallography and structure-based compound optimization to generate a new family of non-peptidic, small-molecule cyclophilin inhibitors with potent in vitro PPIase inhibitory activity and antiviral activity against hepatitis C virus, human immunodeficiency virus and coronaviruses. This family of compounds has the potential for broad-spectrum, high-barrier-to-resistance treatment of viral infections. PMID:27652979

Design, synthesis and biological evaluation of di-substituted cinnamic hydroxamic acids bearing urea/thiourea unit as potent histone deacetylase inhibitors.

PubMed

Ning, Chengqing; Bi, Yanjing; He, Yujun; Huang, WenYuan; Liu, Lifei; Li, Yi; Zhang, Sihan; Liu, Xiaoyu; Yu, Niefang

2013-12-01

A novel class of di-substituted cinnamic hydroxamic acid derivatives containing urea or thiourea unit was designed, synthesized and evaluated as HDAC inhibitors. All tested compounds demonstrated significant HDAC inhibitory activities and anti-proliferative effects against diverse human tumor cell lines. Among them, 7l exhibited most potent pan-HDAC inhibitory activity, with an IC50 value of 130 nM. It also showed strong cellular inhibition against diverse cell lines including HCT-116, MCF-7, MDB-MB-435 and NCI-460, with GI50 values of 0.35, 0.22, 0.51 and 0.48 μM, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Discovery and structure-activity relationships of piperidinone- and piperidine-constrained phenethylamines as novel, potent, and selective dipeptidyl peptidase IV inhibitors.

PubMed

Pei, Zhonghua; Li, Xiaofeng; von Geldern, Thomas W; Longenecker, Kenton; Pireh, Daisy; Stewart, Kent D; Backes, Bradley J; Lai, Chunqiu; Lubben, Thomas H; Ballaron, Stephen J; Beno, David W A; Kempf-Grote, Anita J; Sham, Hing L; Trevillyan, James M

2007-04-19

Dipeptidyl peptidase IV (DPP4) inhibitors are emerging as a new class of therapeutic agents for the treatment of type 2 diabetes. They exert their beneficial effects by increasing the levels of active glucagon-like peptide-1 and glucose-dependent insulinotropic peptide, which are two important incretins for glucose homeostasis. Starting from a high-throughput screening hit, we were able to identify a series of piperidinone- and piperidine-constrained phenethylamines as novel DPP4 inhibitors. Optimized compounds are potent, selective, and have good pharmacokinetic profiles.

Bis-Aryl Urea Derivatives as Potent and Selective LIM Kinase (Limk) Inhibitors

PubMed Central

Yin, Yan; Zheng, Ke; Eid, Nibal; Howard, Shannon; Jeong, Ji-Hak; Yi, Fei; Guo, Jia; Park, Chul M; Bibian, Mathieu; Wu, Weilin; Hernandez, Pamela; Park, HaJeung; Wu, Yuntao; Luo, Jun-Li; LoGrasso, Philip V.; Feng, Yangbo

2015-01-01

The discovery/optimization of bis-aryl ureas as Limk inhibitors to obtain high potency and selectivity, and appropriate pharmacokinetic properties through systematic SAR studies is reported. Docking studies supported the observed SAR. Optimized Limk inhibitors had high biochemical potency (IC50 < 25 nM), excellent selectivity against ROCK and JNK kinases (> 400-fold), potent inhibition of cofilin phosphorylation in A7r5,PC-3, and CEM-SS T cells (IC50 < 1 μM), and good in vitro and in vivo pharmacokinetic properties. In the profiling against a panel of 61 kinases, compound 18b at 1 μM inhibited only Limk1 and STK16 with ≥ 80% inhibition. Compounds 18b and 18f were highly efficient in inhibiting cell-invasion/migration in PC-3 cells. In addition, compound 18w was demonstrated to be effective on reducing intraocular pressure (IOP) on rat eyes. Taken together, these data demonstrated that we had developed a novel class of bis-aryl urea derived potent and selective Limk inhibitors. PMID:25621531

Potent Anti-Inflammatory Activity of Ursolic Acid, a Triterpenoid Antioxidant, Is Mediated through Suppression of NF-κB, AP-1 and NF-AT

PubMed Central

Checker, Rahul; Sandur, Santosh K.; Sharma, Deepak; Patwardhan, Raghavendra S.; Jayakumar, S.; Kohli, Vineet; Sethi, Gautam; Aggarwal, Bharat B.; Sainis, Krishna B.

2012-01-01

Background Ursolic acid (UA), a pentacyclic triterpenoid carboxylic acid, is the major component of many plants including apples, basil, cranberries, peppermint, rosemary, oregano and prunes and has been reported to possess antioxidant and anti-tumor properties. These properties of UA have been attributed to its ability to suppress NF-κB (nuclear factor kappa B) activation. Since NF-κB, in co-ordination with NF-AT (nuclear factor of activated T cells) and AP-1(activator protein-1), is known to regulate inflammatory genes, we hypothesized that UA might exhibit potent anti-inflammatory effects. Methodology/Principal Findings The anti-inflammatory effects of UA were assessed in activated T cells, B cells and macrophages. Effects of UA on ERK, JNK, NF-κB, AP-1 and NF-AT were studied to elucidate its mechanism of action. In vivo efficacy of UA was studied using mouse model of graft-versus-host disease. UA inhibited activation, proliferation and cytokine secretion in T cells, B cells and macrophages. UA inhibited mitogen-induced up-regulation of activation markers and co-stimulatory molecules in T and B cells. It inhibited mitogen-induced phosphorylation of ERK and JNK and suppressed the activation of immunoregulatory transcription factors NF-κB, NF-AT and AP-1 in lymphocytes. Treatment of cells with UA prior to allogenic transplantation significantly delayed induction of acute graft-versus-host disease in mice and also significantly reduced the serum levels of pro-inflammatory cytokines IL-6 and IFN-γ. UA treatment inhibited T cell activation even when added post-mitogenic stimulation demonstrating its therapeutic utility as an anti-inflammatory agent. Conclusions/Significance The present study describes the detailed mechanism of anti-inflammatory activity of UA. Further, UA may find application in the treatment of inflammatory disorders. PMID:22363615

Discovery and characterization of a novel irreversible EGFR mutants selective and potent kinase inhibitor CHMFL-EGFR-26 with a distinct binding mode

PubMed Central

Chen, Cheng; Yu, Kailin; Zou, Fengming; Wang, Wenchao; Wang, Wei; Wu, Jiaxin; Liu, Juan; Wang, Beilei; Wang, Li; Ren, Tao; Zhang, Shanchun; Yun, Cai-Hong; Liu, Jing; Liu, Qingsong

2017-01-01

EGFR T790M mutation accounts for about 40-55% drug resistance for the first generation EGFR kinase inhibitors in the NSCLC. Starting from ibrutinib, a highly potent irreversible BTK kinase inhibitor, which was also found to be moderately active to EGFR T790M mutant, we discovered a highly potent irreversible EGFR inhibitor CHMFL-EGFR-26, which is selectively potent against EGFR mutants including L858R, del19, and L858R/T790M. It displayed proper selectivity window between the EGFR mutants and the wide-type. CHMFL-EGFR-26 exhibited good selectivity profile among 468 kinases/mutants tested (S score (1)=0.02). In addition, X-ray crystallography revealed a distinct “DFG-in” and “cHelix-out” inactive binding mode between CHMFL-EGFR-26 and EGFR T790M protein. The compound showed highly potent anti-proliferative efficacy against EGFR mutant but not wide-type NSCLC cell lines through effective inhibition of the EGFR mediated signaling pathway, induction of apoptosis and arresting of cell cycle progression. CHMFL-EGFR-26 bore acceptable pharmacokinetic properties and demonstrated dose-dependent tumor growth suppression in the H1975 (EGFR L858R/T790M) and PC-9 (EGFR del19) inoculated xenograft mouse models. Currently CHMFL-EGFR-26 is undergoing extensive pre-clinical evaluation for the clinical trial purpose. PMID:28407693

Synthesis and antiviral activity of certain second generation methylenecyclopropane nucleosides

PubMed Central

Williams, John D.; Khan, Atiyya R.; Harden, Emma A.; Hartline, Caroll B.; Jefferson, Geraldine M.; Keith, Kathy A.; Prichard, Mark N.; Zemlicka, Jiri; Peet, Norton P.; Bowlin, Terry L.

2012-01-01

A second-generation series of substituted methylenecyclopropane nucleosides (MCPNs) has been synthesized and evaluated for antiviral activity against a panel of human herpesviruses, and for cytotoxicity. Although alkylated 2,6-diaminopurine analogs showed little antiviral activity, the compounds containing ether and thioether substituents at the 6-position of the purine did demonstrate potent and selective antiviral activity against several different human herpesviruses. In the 6-alkoxy series, antiviral activity depended on the length of the ether carbon chain, with the optimum chain length being about four carbon units long. For the corresponding thioethers, compounds containing secondary thioethers were more potent than those with primary thioethers. PMID:22607883

A Schiff base-derived copper (II) complex is a potent inducer of apoptosis in colon cancer cells by activating the intrinsic pathway.

PubMed

Hajrezaie, Maryam; Paydar, Mohammadjavad; Moghadamtousi, Soheil Zorofchian; Hassandarvish, Pouya; Gwaram, Nura Suleiman; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Looi, Chung Yeng; Ali, Hapipah Mohd; Abdul Majid, Nazia; Abdulla, Mahmood Ameen

2014-01-01

Metal-based drugs with extensive clinical applications hold great promise for the development of cancer chemotherapeutic agents. In the last few decades, Schiff bases and their complexes have become well known for their extensive biological potential. In the present study, we examined the antiproliferative effect of a copper (II) complex on HT-29 colon cancer cells. The Cu(BrHAP)2 Schiff base compound demonstrated a potent antiproliferative effect in HT-29 cells, with an IC50 value of 2.87  μg/ml after 72 h of treatment. HT-29 cells treated with Cu (II) complexes underwent apoptosis death, as exhibited by a progressive elevation in the proportion of the G1 cell population. At a concentration of 6.25  μg/ml, the Cu(BrHAP)2 compound caused significant elevation in ROS production following perturbation of mitochondrial membrane potential and cytochrome c release, as assessed by the measurement of fluorescence intensity in stained cells. Furthermore, the activation of caspases 3/7 and 9 was part of the Cu (II) complex-induced apoptosis, which confirmed the involvement of mitochondrial-mediated apoptosis. Meanwhile, there was no significant activation of caspase-8. Taken together, these results imply that the Cu(BrHAP)2 compound is a potential candidate for further in vivo and clinical colon cancer studies to develop novel chemotherapeutic agents derived from metal-based agents.

Myricetin: a potent approach for the treatment of type 2 diabetes as a natural class B GPCR agonist

PubMed Central

Li, Ying; Zheng, Xuemin; Yi, Xiulin; Liu, Changxiao; Kong, Dexin; Zhang, Jianning; Gong, Min

2017-01-01

The physiologic properties of glucagon-like peptide 1 (GLP-1) make it a potent candidate drug target in the treatment of type 2 diabetes mellitus (T2DM). GLP-1 is capable of regulating the blood glucose level by insulin secretion after administration of oral glucose. The advantages of GLP-1 for the avoidance of hypoglycemia and the control of body weight are attractive despite its poor stability. The clinical efficacies of long-acting GLP-1 derivatives strongly support discovery pursuits aimed at identifying and developing orally active, small-molecule GLP-1 receptor (GLP-1R) agonists. The purpose of this study was to identify and characterize a novel oral agonist of GLP-1R (i.e., myricetin). The insulinotropic characterization of myricetin was performed in isolated islets and in Wistar rats. Long-term oral administration of myricetin demonstrated glucoregulatory activity. The data in this study suggest that myricetin might be a potential drug candidate for the treatment of T2DM as a GLP-1R agonist. Further structural modifications on myricetin might improve its pharmacology and pharmacokinetics.—Li, Y., Zheng, X., Yi, X., Liu, C., Kong, D., Zhang, J., Gong, M. Myricetin: a potent approach for the treatment of type 2 diabetes as a natural class B GPCR agonist. PMID:28270518

Synthesis of organic nitrates of luteolin as a novel class of potent aldose reductase inhibitors.

PubMed

Wang, Qi-Qin; Cheng, Ning; Zheng, Xiao-Wei; Peng, Sheng-Ming; Zou, Xiao-Qing

2013-07-15

Aldose reductase (AR) plays an important role in the design of drugs that prevent and treat diabetic complications. Aldose reductase inhibitors (ARIs) have received significant attentions as potent therapeutic drugs. Based on combination principles, three series of luteolin derivatives were synthesised and evaluated for their AR inhibitory activity and nitric oxide (NO)-releasing capacity in vitro. Eighteen compounds were found to be potent ARIs with IC50 values ranging from (0.099±0.008) μM to (2.833±0.102) μM. O(7)-Nitrooxyethyl-O(3'),O(4')-ethylidene luteolin (La1) showed the most potent AR inhibitory activity [IC50=(0.099±0.008) μM]. All organic nitrate derivatives released low concentrations of NO in the presence of l-cysteine. Structure-activity relationship studies suggested that introduction of an NO donor, protection of the catechol structure, and the ether chain of a 2-carbon spacer as a coupling chain on the luteolin scaffold all help increase the AR inhibitory activity of the resulting compound. This class of NO-donor luteolin derivatives as efficient ARIs offer a new concept for the development and design of new drug for preventive and therapeutic drugs for diabetic complications. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

PubMed

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

2012-09-01

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

Poly (I:C) enhances the anti-tumor activity of canine parvovirus NS1 protein by inducing a potent anti-tumor immune response.

PubMed

Gupta, Shishir Kumar; Yadav, Pavan Kumar; Tiwari, A K; Gandham, Ravi Kumar; Sahoo, A P

2016-09-01

The canine parvovirus NS1 (CPV2.NS1) protein selectively induces apoptosis in the malignant cells. However, for an effective in vivo tumor treatment strategy, an oncolytic agent also needs to induce a potent anti-tumor immune response. In the present study, we used poly (I:C), a TLR3 ligand, as an adjuvant along with CPV2.NS1 to find out if the combination can enhance the oncolytic activity by inducing a potent anti-tumor immune response. The 4T1 mammary carcinoma cells were used to induce mammary tumor in Balb/c mice. The results suggested that poly (I:C), when given along with CPV2.NS1, not only significantly reduced the tumor growth but also augmented the immune response against tumor antigen(s) as indicated by the increase in blood CD4+ and CD8+ counts and infiltration of immune cells in the tumor tissue. Further, blood serum analysis of the cytokines revealed that Th1 cytokines (IFN-γ and IL-2) were significantly upregulated in the treatment group indicating activation of cell-mediated immune response. The present study reports the efficacy of CPV2.NS1 along with poly (I:C) not only in inhibiting the mammary tumor growth but also in generating an active anti-tumor immune response without any visible toxicity. The results of our study may help in developing CPV2.NS1 and poly (I: C) combination as a cancer therapeutic regime to treat various malignancies.

18β-Glycyrrhetinic Acid Derivatives Possessing a Trihydroxylated A Ring Are Potent Gram-Positive Antibacterial Agents.

PubMed

Huang, Li-Rong; Hao, Xiao-Jiang; Li, Qi-Ji; Wang, Dao-Ping; Zhang, Jian-Xin; Luo, Heng; Yang, Xiao-Sheng

2016-04-22

The oleanane-type triterpene 18β-glycyrrhetinic acid (1) was modified chemically through the introduction of a trihydroxylated A ring and an ester moiety at C-20 to enhance its antibacterial activity. Compounds 22, 23, 25, 28, 29, 31, and 32 showed more potent inhibitory activity against Streptomyces scabies than the positive control, streptomycin. Additionally, the inhibitory activity of the most potent compound, 29, against Bacillus subtilis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus was greater than that of the positive controls. The antibacterial mode of action of the active derivatives involved the regulation of the expression of genes associated with peptidoglycans, the respiratory metabolism, and the inherent virulence factors found in bacteria, as determined through a quantitative real-time reverse transcriptase PCR assay.

CDB-4124 and its putative monodemethylated metabolite, CDB-4453, are potent antiprogestins with reduced antiglucocorticoid activity: in vitro comparison to mifepristone and CDB-2914.

PubMed

Attardi, Barbara J; Burgenson, Janet; Hild, Sheri A; Reel, Jerry R; Blye, Richard P

2002-02-25

To obtain selective antiprogestins, we have examined the in vitro antiprogestational/antiglucocorticoid properties of two novel compounds, CDB-4124 and the putative monodemethylated metabolite, CDB-4453, in transcription and receptor binding assays and compared them to CDB-2914 and mifepristone. All four antiprogestins bound with high affinity to rabbit uterine progestin receptors (PR) and recombinant human PR-A and PR-B (rhPR-A, rhPR-B) and were potent inhibitors of R5020-induced transactivation of the PRE2-tk-luciferase (PRE2-tk-LUC) reporter plasmid and endogenous alkaline phosphatase production in T47D-CO human breast cancer cells. None of these compounds exhibited agonist activity in these cells. Induction of luciferase activity was potentiated about five-fold by 8-Br-cAMP under basal conditions and to the same extent in the presence of the PR antagonists. Mifepristone bound to rabbit thymic glucocorticoid receptors (GR) with approximately twice the avidity of the CDB antiprogestins. Inhibition of GR-mediated transcription of PRE2-tk-LUC was assessed in HepG2 human hepatoblastoma cells. Mifepristone exhibited greater antiglucocorticoid activity than CDB-2914, 4124, and 4453, about 12-, 22-, and 185-fold, respectively. Thus, while there was a good correlation between binding to PR and functional activity of these antiprogestins, GR binding was not predictive of their glucocorticoid antagonist activity. In agreement with our in vivo results, CDB-4124 and CDB-4453, as well as CDB-2914, are potent antiprogestins in vitro, but show considerably less antiglucocorticoid activity than mifepristone.

In silico investigation of lavandulyl flavonoids for the development of potent fatty acid synthase-inhibitory prototypes.

PubMed

Oh, Joonseok; Liu, Haining; Park, Hyun Bong; Ferreira, Daneel; Jeong, Gil-Saeng; Hamann, Mark T; Doerksen, Robert J; Na, MinKyun

2017-01-01

Inhibition of fatty acid synthase (FAS) is regarded as a sensible therapeutic strategy for the development of optimal anti-cancer agents. Flavonoids exhibit potent anti-neoplastic properties. The MeOH extract of Sophora flavescens was subjected to chromatographic analyses such as VLC and HPLC for the purification of active flavonoids. The DP4 chemical-shift analysis protocol was employed to investigate the elusive chirality of the lavandulyl moiety of the purified polyphenols. Induced Fit docking protocols and per-residue analyses were utilized to scrutinize structural prerequisites for hampering FAS activity. The FAS-inhibitory activity of the purified flavonoids was assessed via the incorporation of [ 3 H] acetyl-CoA into palmitate. Six flavonoids, including lavandulyl flavanones, were purified and evaluated for FAS inhibition. The lavandulyl flavanone sophoraflavanone G (2) exhibited the highest potency (IC 50 of 6.7±0.2μM), which was more potent than the positive controls. Extensive molecular docking studies revealed the structural requirements for blocking FAS. Per-residue interaction analysis demonstrated that the lavandulyl functional group in the active flavonoids (1-3 and 5) significantly contributed to increasing their binding affinity towards the target enzyme. This research suggests a basis for the in silico design of a lavandulyl flavonoid-based architecture showing anti-cancer effects via enhancement of the binding potential to FAS. FAS inhibition by flavonoids and their derivatives may offer significant potential as an approach to lower the risk of various cancer diseases and related fatalities. In silico technologies with available FAS crystal structures may be of significant use in optimizing preliminary leads. Copyright © 2016 Elsevier B.V. All rights reserved.

In silico investigation of lavandulyl flavonoids for the development of potent fatty acid synthase-inhibitory prototypes

PubMed Central

Oh, Joonseok; Liu, Haining; Park, Hyun Bong; Ferreira, Daneel; Jeong, Gil-Saeng; Hamann, Mark T.; Doerksen, Robert J.; Na, MinKyun

2016-01-01

Background Inhibition of fatty acid synthase (FAS) is regarded as a sensible therapeutic strategy for the development of optimal anti-cancer agents. Flavonoids exhibit potent anti-neoplastic properties. Methods The MeOH extract of Sophora flavescens was subjected to chromatographic analyses such as VLC and HPLC for the purification of active flavonoids. The DP4 chemical-shift analysis protocol was employed to investigate the elusive chirality of the lavandulyl moiety of the purified polyphenols. Induced Fit docking protocols and per-residue analyses were utilized to scrutinize structural prerequisites for hampering FAS activity. The FAS-inhibitory activity of the purified flavonoids was assessed via the incorporation of [3H] acetyl-CoA into palmitate. Results Six flavonoids, including lavandulyl flavanones, were purified and evaluated for FAS inhibition. The lavandulyl flavanone sophoraflavanone G (2) exhibited the highest potency (IC50 of 6.7 ± 0.2 μM), which was more potent than the positive controls. Extensive molecular docking studies revealed the structural requirements for blocking FAS. Per-residue interaction analysis demonstrated that the lavandulyl functional group in the active flavonoids (1–3 and 5) significantly contributed to increasing their binding affinity towards the target enzyme. Conclusion This research suggests a basis for the in silico design of a lavandulyl flavonoid-based architecture showing anti-cancer effects via enhancement of the binding potential to FAS. General significance FAS inhibition by flavonoids and their derivatives may offer significant potential as an approach to lower the risk of various cancer diseases and related fatalities. In silico technologies with available FAS crystal structures may be of significant use in optimizing preliminary leads. PMID:27531709

A Synthetic Analogue of Neopeltolide, 8,9-Dehydroneopeltolide, Is a Potent Anti-Austerity Agent against Starved Tumor Cells.

PubMed

Fuwa, Haruhiko; Sato, Mizuho

2017-10-20

Neopeltolide, an antiproliferative marine macrolide, is known to specifically inhibit complex III of the mitochondrial electron transport chain (mETC). However, details of the biological mode-of-action(s) remain largely unknown. This work demonstrates potent cytotoxic activity of synthetic neopeltolide analogue, 8,9-dehydroneopeltolide (8,9-DNP), against starved human pancreatic adenocarcinoma PANC-1 cells and human non-small cell lung adenocarcinoma A549 cells. 8,9-DNP induced rapid dissipation of the mitochondrial membrane potential and depletion of intracellular ATP level in nutrient-deprived medium. Meanwhile, in spite of mTOR inhibition under starvation conditions, impairment of cytoprotective autophagy was observed as the lipidation of LC3-I to form LC3-II and the degradation of p62 were suppressed. Consequently, cells were severely deprived of energy sources and underwent necrotic cell death. The autophagic flux inhibited by 8,9-DNP could be restored by glucose, and this eventually rescued cells from necrotic death. Thus, 8,9-DNP is a potent anti-austerity agent that impairs mitochondrial ATP synthesis and cytoprotective autophagy in starved tumor cells.

A Synthetic Analogue of Neopeltolide, 8,9-Dehydroneopeltolide, Is a Potent Anti-Austerity Agent against Starved Tumor Cells

PubMed Central

Sato, Mizuho

2017-01-01

Neopeltolide, an antiproliferative marine macrolide, is known to specifically inhibit complex III of the mitochondrial electron transport chain (mETC). However, details of the biological mode-of-action(s) remain largely unknown. This work demonstrates potent cytotoxic activity of synthetic neopeltolide analogue, 8,9-dehydroneopeltolide (8,9-DNP), against starved human pancreatic adenocarcinoma PANC-1 cells and human non-small cell lung adenocarcinoma A549 cells. 8,9-DNP induced rapid dissipation of the mitochondrial membrane potential and depletion of intracellular ATP level in nutrient-deprived medium. Meanwhile, in spite of mTOR inhibition under starvation conditions, impairment of cytoprotective autophagy was observed as the lipidation of LC3-I to form LC3-II and the degradation of p62 were suppressed. Consequently, cells were severely deprived of energy sources and underwent necrotic cell death. The autophagic flux inhibited by 8,9-DNP could be restored by glucose, and this eventually rescued cells from necrotic death. Thus, 8,9-DNP is a potent anti-austerity agent that impairs mitochondrial ATP synthesis and cytoprotective autophagy in starved tumor cells. PMID:29053565

An Overhead Projection Demonstration of Optical Activity

ERIC Educational Resources Information Center

Hill, John W.

1973-01-01

Describes the use of two polarizing lenses, a yellow filter, an oatmeal bos, a piece of cardboard, a 1,000 ml beaker, and an overhead projector to demonstrate compound optical activity to large classes. Indicates the presence of an accuracy within 1-2 degrees of usually acceptable data. (CC)

Multi-target screening mines hesperidin as a multi-potent inhibitor: Implication in Alzheimer's disease therapeutics.

PubMed

Chakraborty, Sandipan; Bandyopadhyay, Jaya; Chakraborty, Sourav; Basu, Soumalee

2016-10-04

Alzheimer's disease (AD) is the most frequent form of neurodegenerative disorder in elderly people. Involvement of several pathogenic events and their interconnections make this disease a complex disorder. Therefore, designing compounds that can inhibit multiple toxic pathways is the most attractive therapeutic strategy in complex disorders like AD. Here, we have designed a multi-tier screening protocol combining ensemble docking to mine BACE1 inhibitor, as well as 2-D QSAR models for anti-amyloidogenic and antioxidant activities. An in house developed phytochemical library of 200 phytochemicals has been screened through this multi-target procedure which mine hesperidin, a flavanone glycoside commonly found in citrus food items, as a multi-potent phytochemical in AD therapeutics. Steady-state and time-resolved fluorescence spectroscopy reveal that binding of hesperidin to the active site of BACE1 induces a conformational transition of the protein from open to closed form. Hesperidin docks close to the catalytic aspartate residues and orients itself in a way that blocks the cavity opening thereby precluding substrate binding. Hesperidin is a high affinity BACE1 inhibitor and only 500 nM of the compound shows complete inhibition of the enzyme activity. Furthermore, ANS and Thioflavin-T binding assay show that hesperidin completely inhibits the amyloid fibril formation which is further supported by atomic force microscopy. Hesperidin exhibits moderate ABTS(+) radical scavenging assay but strong hydroxyl radical scavenging ability, as evident from DNA nicking assay. Present study demonstrates the applicability of a novel multi-target screening procedure to mine multi-potent agents from natural origin for AD therapeutics. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Identification of azabenzimidazoles as potent JAK1 selective inhibitors.

PubMed

Vasbinder, Melissa M; Alimzhanov, Marat; Augustin, Martin; Bebernitz, Geraldine; Bell, Kirsten; Chuaqui, Claudio; Deegan, Tracy; Ferguson, Andrew D; Goodwin, Kelly; Huszar, Dennis; Kawatkar, Aarti; Kawatkar, Sameer; Read, Jon; Shi, Jie; Steinbacher, Stefan; Steuber, Holger; Su, Qibin; Toader, Dorin; Wang, Haixia; Woessner, Richard; Wu, Allan; Ye, Minwei; Zinda, Michael

2016-01-01

We have identified a class of azabenzimidazoles as potent and selective JAK1 inhibitors. Investigations into the SAR are presented along with the structural features required to achieve selectivity for JAK1 versus other JAK family members. An example from the series demonstrated highly selective inhibition of JAK1 versus JAK2 and JAK3, along with inhibition of pSTAT3 in vivo, enabling it to serve as a JAK1 selective tool compound to further probe the biology of JAK1 selective inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative Demonstration of Active and Semi-Passive In Situ Bioremediation Approaches for Perchlorate Impacted Groundwater: Active In Situ Bioremediation Demonstration

DTIC Science & Technology

2013-04-01

demonstration test . 5.1 CONCEPTUAL EXPERIMENTAL DESIGN In concept, the active biobarrier approach involved the use of alternating extraction and injection...16 4.3 GROUNDWATER CHEMISTRY ....................................................................... 18 5.0 TEST DESIGN...20 5.1 CONCEPTUAL EXPERIMENTAL DESIGN

YSL-12, a novel microtubule-destabilizing agent, exerts potent anti-tumor activity against colon cancer in vitro and in vivo.

PubMed

Cai, De; Qiu, Zhiqing; Yao, Weimin; Liu, Yuyu; Huang, Haixiang; Liao, Sihai; Luo, Qun; Xie, Liming; Lin, Zhixiu

2016-06-01

Microtubules play a central role in various fundamental cell functions and thus become an attractive target for cancer therapy. A novel compound YSL-12 is a combretastatin A-4 (CA-4) analogue with more stability. We investigated its anti-tumor activity and mechanisms in vitro and in vivo for the first time. Cytotoxicity was evaluated by MTT method. In vitro microtubule polymerization assay was performed using a fluorescence-based method by multifunction fluorescence microplate reader. Intracellular microtubule network was detected by immunofluorescence method. Cell cycle analysis and apoptosis were measured by flow cytometry. Metabolic stability was recorded by liquid chromatography-ultraviolet detection and liquid chromatography-mass spectrometry. In vivo anti-tumor activity was assessed using HT-29 colon carcinoma xenografts established in BALB/c nude mice. YSL-12 displayed nanomolar-level cytotoxicity against various human cancer cell lines. A high selectivity toward normal cells and potent activity toward drug-resistant cells were also observed. YSL-12 was identified as tubulin polymerization inhibitor evidenced by effectively inhibits tubulin polymerization and heavily disrupted microtubule networks in living HT-29 cells. YSL-12 displayed potent disruption effect of pre-established tumor vasculature in vitro. In addition, YSL-12 treatment also caused cell cycle arrest in the G2/M phase and induced cell apoptosis in a dose-dependent manner. In vitro metabolic stability study revealed YSL-12 displayed considerable better stability than CA-4 in liver microsomes. In vivo, YSL-12 delayed tumor growth with 69.4 % growth inhibition. YSL-12 is a promising microtubule inhibitor that has great potential for the treatment of colon carcinoma in vitro and in vivo and worth being a candidate for further development of cancer therapy.

Activation of TRPM3 by a potent synthetic ligand reveals a role in peptide release

PubMed Central

Held, Katharina; Kichko, Tatjana; De Clercq, Katrien; Klaassen, Hugo; Van Bree, Rieta; Vanherck, Jean-Christophe; Marchand, Arnaud; Reeh, Peter W.; Chaltin, Patrick; Voets, Thomas; Vriens, Joris

2015-01-01

Transient receptor potential (TRP) cation channel subfamily M member 3 (TRPM3), a member of the TRP channel superfamily, was recently identified as a nociceptor channel in the somatosensory system, where it is involved in the detection of noxious heat; however, owing to the lack of potent and selective agonists, little is known about other potential physiological consequences of the opening of TRPM3. Here we identify and characterize a synthetic TRPM3 activator, CIM0216, whose potency and apparent affinity greatly exceeds that of the canonical TRPM3 agonist, pregnenolone sulfate (PS). In particular, a single application of CIM0216 causes opening of both the central calcium-conducting pore and the alternative cation permeation pathway in a membrane-delimited manner. CIM0216 evoked robust calcium influx in TRPM3-expressing somatosensory neurons, and intradermal injection of the compound induced a TRPM3-dependent nocifensive behavior. Moreover, CIM0216 elicited the release of the peptides calcitonin gene-related peptide (CGRP) from sensory nerve terminals and insulin from isolated pancreatic islets in a TRPM3-dependent manner. These experiments identify CIM0216 as a powerful tool for use in investigating the physiological roles of TRPM3, and indicate that TRPM3 activation in sensory nerve endings can contribute to neurogenic inflammation. PMID:25733887

Design, synthesis, and in vivo SAR of a novel series of pyrazolines as potent selective androgen receptor modulators.

PubMed

Zhang, Xuqing; Li, Xiaojie; Allan, George F; Sbriscia, Tifanie; Linton, Olivia; Lundeen, Scott G; Sui, Zhihua

2007-08-09

A novel series of pyrazolines 2 have been designed, synthesized, and evaluated by in vivo screening as tissue-selective androgen receptor modulators (SARMs). Structure-activity relationships (SAR) were investigated at the R1 to R6 positions as well as the core pyrazoline ring and the anilide linker. Overall, strong electron-withdrawing groups at the R1 and R2 positions and a small group at the R5 and R6 position are optimal for AR agonist activity. The (S)-isomer of 7c exhibits more potent AR agonist activity than the corresponding (R)-isomer. (S)-7c exhibited an overall partial androgenic effect but full anabolic effect via oral administration in castrated rats. It demonstrated a noticeable antiandrogenic effect on prostate in intact rats with endogenous testosterone. Thus, (S)-7c is a tissue-selective nonsteroidal androgen receptor modulator with agonist activity on muscle and mixed agonist and antagonist activity on prostate.

New potent and selective cytochrome P450 2B6 (CYP2B6) inhibitors based on three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis

PubMed Central

Korhonen, L E; Turpeinen, M; Rahnasto, M; Wittekindt, C; Poso, A; Pelkonen, O; Raunio, H; Juvonen, R O

2007-01-01

Background and purpose: The cytochrome P450 2B6 (CYP2B6) enzyme metabolises a number of clinically important drugs. Drug-drug interactions resulting from inhibition or induction of CYP2B6 activity may cause serious adverse effects. The aims of this study were to construct a three-dimensional structure-activity relationship (3D-QSAR) model of the CYP2B6 protein and to identify novel potent and selective inhibitors of CYP2B6 for in vitro research purposes. Experimental approach: The inhibition potencies (IC50 values) of structurally diverse chemicals were determined with recombinant human CYP2B6 enzyme. Two successive models were constructed using Comparative Molecular Field Analysis (CoMFA). Key results: Three compounds proved to be very potent and selective competitive inhibitors of CYP2B6 in vitro (IC50<1 μM): 4-(4-chlorobenzyl)pyridine (CBP), 4-(4-nitrobenzyl)pyridine (NBP), and 4-benzylpyridine (BP). A complete inhibition of CYP2B6 activity was achieved with 0.1 μM CBP, whereas other CYP-related activities were not affected. Forty-one compounds were selected for further testing and construction of the final CoMFA model. The created CoMFA model was of high quality and predicted accurately the inhibition potency of a test set (n=7) of structurally diverse compounds. Conclusions and implications: Two CoMFA models were created which revealed the key molecular characteristics of inhibitors of the CYP2B6 enzyme. The final model accurately predicted the inhibitory potencies of several structurally unrelated compounds. CBP, BP and NBP were identified as novel potent and selective inhibitors of CYP2B6 and CBP especially is a suitable inhibitor for in vitro screening studies. PMID:17325652

A novel, selective inhibitor of fibroblast growth factor receptors that shows a potent broad spectrum of antitumor activity in several tumor xenograft models.

PubMed

Zhao, Genshi; Li, Wei-Ying; Chen, Daohong; Henry, James R; Li, Hong-Yu; Chen, Zhaogen; Zia-Ebrahimi, Mohammad; Bloem, Laura; Zhai, Yan; Huss, Karen; Peng, Sheng-Bin; McCann, Denis J

2011-11-01

The fibroblast growth factor receptors (FGFR) are tyrosine kinases that are present in many types of endothelial and tumor cells and play an important role in tumor cell growth, survival, and migration as well as in maintaining tumor angiogenesis. Overexpression of FGFRs or aberrant regulation of their activities has been implicated in many forms of human malignancies. Therefore, targeting FGFRs represents an attractive strategy for development of cancer treatment options by simultaneously inhibiting tumor cell growth, survival, and migration as well as tumor angiogenesis. Here, we describe a potent, selective, small-molecule FGFR inhibitor, (R)-(E)-2-(4-(2-(5-(1-(3,5-Dichloropyridin-4-yl)ethoxy)-1H-indazol-3yl)vinyl)-1H-pyrazol-1-yl)ethanol, designated as LY2874455. This molecule is active against all 4 FGFRs, with a similar potency in biochemical assays. It exhibits a potent activity against FGF/FGFR-mediated signaling in several cancer cell lines and shows an excellent broad spectrum of antitumor activity in several tumor xenograft models representing the major FGF/FGFR relevant tumor histologies including lung, gastric, and bladder cancers and multiple myeloma, and with a well-defined pharmacokinetic/pharmacodynamic relationship. LY2874455 also exhibits a 6- to 9-fold in vitro and in vivo selectivity on inhibition of FGF- over VEGF-mediated target signaling in mice. Furthermore, LY2874455 did not show VEGF receptor 2-mediated toxicities such as hypertension at efficacious doses. Currently, this molecule is being evaluated for its potential use in the clinic.

Identification and Quantitation of Potent Odorants in Spearmint Oils.

PubMed

Kelley, Lauren E; Cadwallader, Keith R

2018-03-14

Potent odorants in Native spearmint, Scotch spearmint, and Macho mint oils were determined by the combined use of gas chromatography-olfactometry (GCO), gas chromatography-mass spectrometry (GC-MS), and aroma extract dilution analysis (AEDA). Of the 85 odorants detected, ( R)-(-)-carvone was the most potent odorant in all three spearmint oils. Additional predominant odorants in all spearmint oils included eugenol, ethyl ( S)-(+)-2-methylbutanoate, ( E)-β-damascenone, and (3 E,5 Z)-1,3,5-undecatriene. Forty-six compounds were quantitated using various methods, including 19 by gas chromatography with flame ionization detection (GC-FID), 20 by stable isotope dilution analysis (SIDA), and 14 by GCO dilution analysis. Concentrations were used to calculate the odor activity values (OAVs) for predominant odorants in the oils. Among the compounds quantitated, those with the highest OAVs were ( R)-(-)-carvone, 1,8-cineole, ( E, Z)-2,6-nonadienal, ( E)-β-damascenone, and (3 E,5 Z)-1,3,5-undecatriene.

In vitro and in vivo biological activities of SR140333, a novel potent non-peptide tachykinin NK1 receptor antagonist.

PubMed

Emonds-Alt, X; Doutremepuich, J D; Heaulme, M; Neliat, G; Santucci, V; Steinberg, R; Vilain, P; Bichon, D; Ducoux, J P; Proietto, V

1993-12-21

(S)1-(2-[3-(3,4-dichlorophenyl)-1-(3-isopropoxyphenylacetyl)pip eridin-3- yl]ethyl)-4-phenyl-1-azoniabicyclo[2.2.2]octane chloride (SR140333) is a new non-peptide antagonist of tachykinin NK1 receptors. SR140333 potently, selectively and competitively inhibited substance P binding to NK1 receptors from various animal species, including humans. In vitro, it was a potent antagonist in functional assays for NK1 receptors such as [Sar9,Met(O2)11]substance P-induced endothelium-dependent relaxation of rabbit pulmonary artery and contraction of guinea-pig ileum. Up to 1 microM, it had no effect in bioassays for NK2 ([beta Ala8]neurokinin A-induced contraction of endothelium-deprived rabbit pulmonary artery) and NK3 ([MePhe7]neurokinin B-induced contraction of rat portal vein) receptors. The antagonism exerted by SR140333 toward NK1 receptors was apparently non-competitive, with pD2' values (antagonism potency evaluated by the negative logarithm of the molar concentration of antagonist that produces a 50% reduction of the maximal response to the agonist) between 9.65 and 10.16 in the different assays. SR140333 also blocked in vitro [Sar9,Met(O2)11]substance P-induced release of acetylcholine from rat striatum. In vivo, SR140333 exerted highly potent antagonism toward [Sar9,Met(O2)11]substance P-induced hypotension in dogs (ED50 = 3 micrograms/kg i.v.), bronchoconstriction in guinea-pig (ED50 = 42 micrograms/kg i.v.) and plasma extravasation in rats (ED50 = 7 micrograms/kg i.v.). Finally, it also blocked the activation of rat thalamic neurons after nociceptive stimulation (ED50 = 0.2 micrograms/kg i.v.).

Quercetin is a potent anti-atherosclerotic compound by activation of SIRT1 signaling under oxLDL stimulation.

PubMed

Hung, Ching-Hsia; Chan, Shih-Hung; Chu, Pei-Ming; Tsai, Kun-Ling

2015-10-01

Atherosclerosis is believed to be an independent predictor of cardiovascular diseases. A growing body of evidence suggests that quercetin is a potent antioxidant and anti-inflammatory compound. The molecular mechanisms underlying its protective effects against oxidative stress in human endothelial cells remain unclear. This study was designed to confirm the hypothesis that quercetin inhibits oxidized LDL (oxLDL) induced endothelial oxidative damage by activating sirtuin 1 (SIRT1) and to explore the role of adenosine monophosphate activated protein kinase (AMPK), which is a negative regulator of Nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) and free radicals. Human umbilical vein endothelial cells were treated with oxLDL with or without quercetin pretreatment. We found that quercetin pretreatment increased SIRT1 mRNA expression. In fact, quercetin protected against oxLDL-impaired SIRT1 and AMPK activities and reduced oxLDL-activated NOX2 and NOX4. However, silencing SIRT1 and AMPK diminished the protective function of quercetin against oxidative injuries. The results also indicated that oxLDL suppressed AKT/endothelial NO synthase, impaired mitochondrial dysfunction, and enhanced reactive oxygen species formation, activating the Nuclear Factor Kappa B (NF-κB) pathway. These results provide new insight regarding the possible molecular mechanisms of quercetin. Quercetin suppresses oxLDL-induced endothelial oxidative injuries by activating SIRT1 and modulating the AMPK/NADPH oxidase/AKT/endothelial NO synthase signaling pathway. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potent anti-seizure effects of D-leucine

PubMed Central

Hartman, Adam L.; Santos, Polan; O’Riordan, Kenneth J.; Stafstrom, Carl E.; Hardwick, J. Marie

2015-01-01

There are no effective treatments for millions of patients with intractable epilepsy. High-fat ketogenic diets may provide significant clinical benefit but are challenging to implement. Low carbohydrate levels appear to be essential for the ketogenic diet to work, but the active ingredients in dietary interventions remain elusive, and a role for ketogenesis has been challenged. A potential antiseizure role of dietary protein or of individual amino acids in the ketogenic diet is understudied. We investigated the two exclusively ketogenic amino acids, L-leucine and L-lysine, and found that only L-leucine potently protects mice when administered prior to the onset of seizures induced by kainic acid injection, but not by inducing ketosis. Unexpectedly, the D-enantiomer of leucine, which is found in trace amounts in the brain, worked as well or better than L-leucine against both kainic acid and 6 Hz electroshock-induced seizures. However, unlike L-leucine, D-leucine potently terminated seizures even after the onset of seizure activity. Furthermore, D-leucine, but not L-leucine, reduced long-term potentiation but had no effect on basal synaptic transmission in vitro. In a screen of candidate neuronal receptors, D-leucine failed to compete for binding by cognate ligands, potentially suggesting a novel target. Even at low doses, D-leucine suppressed ongoing seizures at least as effectively as diazepam but without sedative effects. These studies raise the possibility that D-leucine may represent a new class of anti-seizure agents, and that D-leucine may have a previously unknown function in eukaryotes. PMID:26054437

Nucleobases and corresponding nucleosides display potent antiviral activities against dengue virus possibly through viral lethal mutagenesis.

PubMed

Qiu, Li; Patterson, Steven E; Bonnac, Laurent F; Geraghty, Robert J

2018-04-01

Dengue virus affects millions of people worldwide each year. To date, there is no drug for the treatment of dengue-associated disease. Nucleosides are effective antivirals and work by inhibiting the accurate replication of the viral genome. Nucleobases offer a cheaper alternative to nucleosides for broad antiviral applications. Metabolic activation of nucleobases involves condensation with 5-phosphoribosyl-1-pyrophosphate to give the corresponding nucleoside-5'-monophosphate. This could provide an alternative to phosphorylation of a nucleoside, a step that is often rate limiting and inefficient in activation of nucleosides. We evaluated more than 30 nucleobases and corresponding nucleosides for their antiviral activity against dengue virus. Five nucleobases and two nucleosides were found to induce potent antiviral effects not previously described. Our studies further revealed that nucleobases were usually more active with a better tissue culture therapeutic index than their corresponding nucleosides. The development of viral lethal mutagenesis, an antiviral approach that takes into account the quasispecies behavior of RNA viruses, represents an exciting prospect not yet studied in the context of dengue replication. Passage of the virus in the presence of the nucleobase 3a (T-1105) and corresponding nucleoside 3b (T-1106), favipiravir derivatives, induced an increase in apparent mutations, indicating lethal mutagenesis as a possible antiviral mechanism. A more concerted and widespread screening of nucleobase libraries is a very promising approach to identify dengue virus inhibitors including those that may act as viral mutagens.

Design and synthesis of a novel series of [1-(4-hydroxy-benzyl)-1H-indol-5-yloxy]-acetic acid compounds as potent, selective, thyroid hormone receptor β agonists.

PubMed

Burkholder, Timothy P; Cunningham, Brian E; Clayton, Joshua R; Lander, Peter A; Brown, Matthew L; Doti, Robert A; Durst, Gregory L; Montrose-Rafizadeh, Chahrzad; King, Constance; Osborne, Harold E; Amos, Robert M; Zink, Richard W; Stramm, Lawrence E; Burris, Thomas P; Cardona, Guemalli; Konkol, Debra L; Reidy, Charles; Christe, Michael E; Genin, Michael J

2015-04-01

The design, synthesis, and structure activity relationships for a novel series of indoles as potent, selective, thyroid hormone receptor β (TRβ) agonists is described. Compounds with >50× binding selectivity for TRβ over TRα were generated and evaluation of compound 1c from this series in a model of dyslipidemia demonstrated positive effects on plasma lipid endpoints in vivo. Copyright © 2015 Elsevier Ltd. All rights reserved.

DCPIB, a potent volume-regulated anion channel antagonist, attenuates microglia-mediated inflammatory response and neuronal injury following focal cerebral ischemia.

PubMed

Han, Qingdong; Liu, Shengwen; Li, Zhengwei; Hu, Feng; Zhang, Qiang; Zhou, Min; Chen, Jingcao; Lei, Ting; Zhang, Huaqiu

2014-01-13

Accumulating evidence indicates that extensive microglia activation-mediated local inflammation contributes to neuronal injury in cerebral ischemia. We have previously shown that 4-(2-butyl-6, 7-dichloro-2-cyclopentyl-indan-1-on-5-yl) oxobutyric acid (DCPIB), a potent volume-regulated anion channel (VRAC) inhibitor, suppresses pathological glutamate release and excitatory neurotoxicity in reversible middle cerebral artery occlusion (rMCAO) model in vivo. In the present study, we sought to determine whether DCPIB also attenuates microglia activation that could contribute to neuronal injury in the cerebral ischemia/reperfusion pathology. We show that oxygen-glucose deprivation (OGD) induced microglia proliferation, migration, and secretion of cytokines and all these pathological changes were effectively inhibited by DCPIB in vitro. In the microglia/neuron co-cultures, OGD induced neuronal damage was reduced markedly in the presence of DCPIB. In rat rMCAO animal model, DCPIB significantly attenuated microglia activation and neuronal death. Activation of mitogen-activated protein kinase (MAPK) signaling pathway is known to be a critical signaling pathway for microglia activation. We further explored a potential involvement of DCPIB in this pathway by western blot analysis. Under the conditions that MAPK pathway was activated either by lipopolysaccharides (LPS) or OGD, the levels of phosphorylated ERK1/2, JNK and p38 were reduced significantly in the presence of DCPIB. Altogether, our study demonstrated that DCPIB inhibits microglia activation potently under ischemic conditions both in vitro and in vivo. The DCPIB effect is likely attributable to both direct inhibition VRAC and indirect inhibition of MAPK pathway in microglia that are beneficial for the survival of neurons in cerebral ischemic conditions. © 2013 Elsevier B.V. All rights reserved.

A Schiff Base-Derived Copper (II) Complex Is a Potent Inducer of Apoptosis in Colon Cancer Cells by Activating the Intrinsic Pathway

PubMed Central

Hajrezaie, Maryam; Paydar, Mohammadjavad; Zorofchian Moghadamtousi, Soheil; Hassandarvish, Pouya; Gwaram, Nura Suleiman; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Looi, Chung Yeng; Ali, Hapipah Mohd; Abdul Majid, Nazia; Abdulla, Mahmood Ameen

2014-01-01

Metal-based drugs with extensive clinical applications hold great promise for the development of cancer chemotherapeutic agents. In the last few decades, Schiff bases and their complexes have become well known for their extensive biological potential. In the present study, we examined the antiproliferative effect of a copper (II) complex on HT-29 colon cancer cells. The Cu(BrHAP)2 Schiff base compound demonstrated a potent antiproliferative effect in HT-29 cells, with an IC50 value of 2.87 μg/ml after 72 h of treatment. HT-29 cells treated with Cu (II) complexes underwent apoptosis death, as exhibited by a progressive elevation in the proportion of the G1 cell population. At a concentration of 6.25 μg/ml, the Cu(BrHAP)2 compound caused significant elevation in ROS production following perturbation of mitochondrial membrane potential and cytochrome c release, as assessed by the measurement of fluorescence intensity in stained cells. Furthermore, the activation of caspases 3/7 and 9 was part of the Cu (II) complex-induced apoptosis, which confirmed the involvement of mitochondrial-mediated apoptosis. Meanwhile, there was no significant activation of caspase-8. Taken together, these results imply that the Cu(BrHAP)2 compound is a potential candidate for further in vivo and clinical colon cancer studies to develop novel chemotherapeutic agents derived from metal-based agents. PMID:24737979

Discovery of 3-(3-(4-(1-Aminocyclobutyl)phenyl)-5-phenyl-3 H -imidazo[4,5- b ]pyridin-2-yl)pyridin-2-amine (ARQ 092): An Orally Bioavailable, Selective, and Potent Allosteric AKT Inhibitor

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

Lapierre, Jean-Marc; Eathiraj, Sudharshan; Vensel, David

The work in this paper describes the optimization of the 3-(3-phenyl-3H-imidazo[4,5-b]pyridin-2-yl)pyridin-2-amine chemical series as potent, selective allosteric inhibitors of AKT kinases, leading to the discovery of ARQ 092 (21a). The cocrystal structure of compound 21a bound to full-length AKT1 confirmed the allosteric mode of inhibition of this chemical class and the role of the cyclobutylamine moiety. Compound 21a demonstrated high enzymatic potency against AKT1, AKT2, and AKT3, as well as potent cellular inhibition of AKT activation and the phosphorylation of the downstream target PRAS40. Compound 21a also served as a potent inhibitor of the AKT1-E17K mutant protein and inhibited tumormore » growth in a human xenograft mouse model of endometrial adenocarcinoma.« less

Leiodermatolide, a novel marine natural product, has potent cytotoxic and anti-mitotic activity against cancer cells, appears to affect microtubule dynamics, and exhibits anti-tumor activity

PubMed Central

Guzmán, Esther A.; Xu, Qunli; Pitts, Tara P.; Mitsuhashi, Kaoru Ogawa; Baker, Cheryl; Linley, Patricia A.; Oestreicher, Judy; Tendyke, Karen; Winder, Priscilla L.; Suh, Edward M.; Wright, Amy E.

2016-01-01

Pancreatic cancer, the fourth leading cause of cancer death in the United States, has a negative prognosis because metastasis occurs before symptoms manifest. Leiodermatolide, a polyketide macrolide with antimitotic activity isolated from a deep water sponge of the genus Leiodermatium, exhibits potent and selective cytotoxicity towards the pancreatic cancer cell lines AsPC-1, PANC-1, BxPC-3, and MIA PaCa-2, and potent cytotoxicity against skin, breast and colon cancer cell lines. Induction of apoptosis by leiodermatolide was confirmed in the AsPC-1, BxPC-3 and MIA PaCa-2 cells. Leiodermatolide induces cell cycle arrest but has no effects on in vitro polymerization or depolymerization of tubulin alone, while it enhances polymerization of tubulin containing microtubule associated proteins (MAPs). Observations through confocal microscopy show that leiodermatolide, at low concentrations, causes minimal effects on polymerization or depolymerization of the microtubule network in interphase cells, but disruption of spindle formation in mitotic cells. At higher concentrations, depolymerization of the microtubule network is observed. Visualization of the growing microtubule in HeLa cells expressing GFP-tagged plus end binding protein EB-1 showed that leiodermatolide stopped the polymerization of tubulin. These results suggest that leiodermatolide may affect tubulin dynamics without directly interacting with tubulin and hint at a unique mechanism of action. In a mouse model of metastatic pancreatic cancer, leiodermatolide exhibited significant tumor reduction when compared to gemcitabine and controls. The anti-tumor activities of leiodermatolide, as well as the proven utility of anti-mitotic compounds against cancer, make leiodermatolide an interesting compound with potential chemotherapeutic effects that may merit further research. PMID:27376928

Phenolic derivatives from soy flour ethanol extract are potent in vitro quinone reductase (QR) inducing agents.

PubMed

Bolling, Bradley W; Parkin, Kirk L

2008-11-26

The fractionation of soy flour directed by a cellular bioassay for induction of phase 2 detoxification enzymes was used to identify quinone reductase (QR) inducing agents. A phospholipid-depleted, 80% methanol-partitioned isolate from a crude ethanol extract of soy flour was resolved using normal phase medium-pressure liquid chromatography (MPLC). Early eluting fractions were found to be the most potent QR inducing agents among the separated fractions. Fraction 2 was the most potent, doubling QR at <2 mug/mL. Further fractionation of this isolate led to the identification of several constituents. Fatty acids and sn-1 and sn-2 monoacylglycerols were identified, but were not highly potent QR inducers. Benzofuran-3-carbaldehyde, 4-hydroxybenzaldeyde, 4-ethoxybenzoic acid, 4-ethoxycinnamic acid, benzofuran-2-carboxylic ethyl ester, and ferulic acid ethyl ester (FAEE) were also identified as QR inducing constituents of this fraction. FAEE was the most potent of the identified constituents, doubling QR specific activity at 3.2 muM in the cellular bioassay.

Characterization of the biological activity of a potent small molecule Hec1 inhibitor TAI-1

PubMed Central

2014-01-01

Background Hec1 (NDC80) is an integral part of the kinetochore and is overexpressed in a variety of human cancers, making it an attractive molecular target for the design of novel anticancer therapeutics. A highly potent first-in-class compound targeting Hec1, TAI-1, was identified and is characterized in this study to determine its potential as an anticancer agent for clinical utility. Methods The in vitro potency, cancer cell specificity, synergy activity, and markers for response of TAI-1 were evaluated with cell lines. Mechanism of action was confirmed with western blotting and immunofluorescent staining. The in vivo potency of TAI-1 was evaluated in three xenograft models in mice. Preliminary toxicity was evaluated in mice. Specificity to the target was tested with a kinase panel. Cardiac safety was evaluated with hERG assay. Clinical correlation was performed with human gene database. Results TAI-1 showed strong potency across a broad spectrum of tumor cells. TAI-1 disrupted Hec1-Nek2 protein interaction, led to Nek2 degradation, induced significant chromosomal misalignment in metaphase, and induced apoptotic cell death. TAI-1 was effective orally in in vivo animal models of triple negative breast cancer, colon cancer and liver cancer. Preliminary toxicity shows no effect on the body weights, organ weights, and blood indices at efficacious doses. TAI-1 shows high specificity to cancer cells and to target and had no effect on the cardiac channel hERG. TAI-1 is synergistic with doxorubicin, topotecan and paclitaxel in leukemia, breast and liver cancer cells. Sensitivity to TAI-1 was associated with the status of RB and P53 gene. Knockdown of RB and P53 in cancer cells increased sensitivity to TAI-1. Hec1-overexpressing molecular subtypes of human lung cancer were identified. Conclusions The excellent potency, safety and synergistic profiles of this potent first-in-class Hec1-targeted small molecule TAI-1 show its potential for clinically utility in anti

Ab Initio Design of Potent Anti-MRSA Peptides based on Database Filtering Technology

PubMed Central

Mishra, Biswajit; Wang, Guangshun

2012-01-01

To meet the challenge of antibiotic resistance worldwide, a new generation of antimicrobials must be developed.1 This communication demonstrates ab initio design of potent peptides against methicillin-resistant Staphylococcus aureus (MRSA). Our idea is that the peptide is very likely to be active when most probable parameters are utilized in each step of the design. We derived the most probable parameters (e.g. amino acid composition, peptide hydrophobic content, and net charge) from the antimicrobial peptide database2 by developing a database filtering technology (DFT). Different from classic cationic antimicrobial peptides usually with high cationicity, DFTamP1, the first anti-MRSA peptide designed using this technology, is a short peptide with high hydrophobicity but low cationicity. Such a molecular design made the peptide highly potent. Indeed, the peptide caused bacterial surface damage and killed community-associated MRSA USA300 in 60 minutes. Structural determination of DFTamP1 by NMR spectroscopy revealed a broad hydrophobic surface, providing a basis for its potency against MRSA known to deploy positively charged moieties on the surface as a mechanism for resistance. A combination of our ab initio design with database screening3 led to yet another peptide with enhanced potency. Because of simple composition, short length, stability to proteases, and membrane targeting, the designed peptides are attractive leads for developing novel anti-MRSA therapeutics. Our database-derived design concept can be applied to the design of peptide mimicries to combat MRSA as well. PMID:22803960

Ab initio design of potent anti-MRSA peptides based on database filtering technology.

PubMed

Mishra, Biswajit; Wang, Guangshun

2012-08-01

To meet the challenge of antibiotic resistance worldwide, a new generation of antimicrobials must be developed. This communication demonstrates ab initio design of potent peptides against methicillin-resistant Staphylococcus aureus (MRSA). Our idea is that the peptide is very likely to be active when the most probable parameters are utilized in each step of the design. We derived the most probable parameters (e.g., amino acid composition, peptide hydrophobic content, and net charge) from the antimicrobial peptide database by developing a database filtering technology (DFT). Different from classic cationic antimicrobial peptides usually with high cationicity, DFTamP1, the first anti-MRSA peptide designed using this technology, is a short peptide with high hydrophobicity but low cationicity. Such a molecular design made the peptide highly potent. Indeed, the peptide caused bacterial surface damage and killed community-associated MRSA USA300 in 60 min. Structural determination of DFTamP1 by NMR spectroscopy revealed a broad hydrophobic surface, providing a basis for its potency against MRSA known to deploy positively charged moieties on the surface as a mechanism for resistance. Our ab initio design combined with database screening led to yet another peptide with enhanced potency. Because of the simple composition, short length, stability to proteases, and membrane targeting, the designed peptides are attractive leads for developing novel anti-MRSA therapeutics. Our database-derived design concept can be applied to the design of peptide mimicries to combat MRSA as well.

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.

Discovery and characterization of novel imidazopyridine derivative CHEQ-2 as a potent CDC25 inhibitor and promising anticancer drug candidate.

PubMed

Song, Yu'ning; Lin, Xiaoqian; Kang, Dongwei; Li, Xiao; Zhan, Peng; Liu, Xinyong; Zhang, Qingzhu

2014-07-23

Cell division cycle (CDC) 25 proteins are key phosphatases regulating cell cycle transition and proliferation via the interactions with CDK/Cyclin complexes. Overexpression of CDC25 proteins is frequently observed in cancer and is related to aggressiveness, high-grade tumors and poor prognosis. Thus, inhibiting CDC25 activity in cancer treatment appears a good therapeutic strategy. In this article, refinement of the initial hit XDW-1 by synthesis and screening of a focused compound library led to the identification of a novel set of imidazopyridine derivatives as potent CDC25 inhibitors. Among them, the most potent molecule was CHEQ-2, which could efficiently inhibit the activities of CDC25A/B enzymes as well as the proliferation of various different types of cancer cell lines in vitro assay. Moreover, CHEQ-2 triggered S-phase cell cycle arrest in MCF-7, HepG2 and HT-29 cell lines, accompanied by generation of ROS, mitochondrial dysfunction and apoptosis. Besides, oral administration of CHEQ-2 (10 mg/kg) significantly inhibited xenografted human liver tumor growth in nude mice, while demonstrated extremely low toxicity (LD50 > 2000 mg/kg). These findings make CHEQ-2 a good starting point for further investigation and structure modification. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Induction of ovulation by a potent, orally active, low molecular weight agonist (Org 43553) of the luteinizing hormone receptor.

PubMed

van de Lagemaat, R; Timmers, C M; Kelder, J; van Koppen, C; Mosselman, S; Hanssen, R G J M

2009-03-01

In assisted reproductive technology, human chorionic gonadotrophin (hCG) is administered subcutaneously for the induction of oocyte maturation and ovulation. Our efforts to develop orally bioavailable luteinizing hormone (LH) receptor agonists have led to the discovery of Org 43553, a low molecular weight (LMW) LH receptor (LH-R) agonist. Org 43553 was tested in vitro and in vivo in pre-clinical pharmacological models to demonstrate efficacy and oral availability. Org 43553 is a potent stimulator of the human LH-R in vitro (EC(50) 3.7 nM). In primary mouse Leydig cells, Org 43553 stimulated testosterone production. Pharmacokinetic analyses showed high oral bioavailability in rats (79%) and dogs (44%) with a shorter half-life compared with hCG (3.4 versus 5.6 h in the rat). Ovulation induction by Org 43553 was demonstrated in immature mice as well as in cyclic rats after single-dose oral administration (50 mg/kg). The ovulated oocytes were of good quality as demonstrated by successful fertilization and implantation of normal embryos. In male rats, testosterone production was substantially induced after oral administration. Org 43553 is the first LMW LH-R mimetic with demonstrated in vivo efficacy upon oral administration and could therefore replace subcutaneously administered hCG. The elimination half-life of Org 43553 is substantially shorter than hCG, which could potentially represent a clinical benefit in reducing the risk of ovarian hyperstimulation syndrome (OHSS).

Pseudoephedrine/ephedrine shows potent anti-inflammatory activity against TNF-α-mediated acute liver failure induced by lipopolysaccharide/D-galactosamine.

PubMed

Wu, Zhongping; Kong, Xiangliang; Zhang, Tong; Ye, Jin; Fang, Zhaoqin; Yang, Xuejun

2014-02-05

The anti-inflammatory effects of pseudoephedrine/ephedrine were investigated using the experimental model of lipopolysaccharide (LPS)-induced acute liver failure in D-galactosamine (D-GalN)-sensitised male rats in order to elucidate effects other than sympathomimetic effects. Rats were intraperitoneally injected with D-GalN (400 mg/kg) and LPS (40 μg/kg) to induce acute liver failure. The treatment groups were then intraperitoneally administered pseudoephedrine/ephedrine at 0 h and 4 h after induction and the activation induced by treatment with pseudoephedrine and/or LPS on the primary Kupffer cells (KCs) was monitored. Compared with controls induced by GalN/LPS alone, pseudoephedrine dramatically reduced the infiltration of inflammatory cells and bile ductular hyperplasia and hepatic necrosis observed in liver sections. It inhibited both hepatocellular apoptosis and the expression of monocyte chemotactic protein-1. It lowered the production of tumour necrosis factor-α (TNF-α) in the beginning of acute liver failure induced by D-GalN/LPS. Correspondingly, levels of alanine aminotransferase (ALT), total bilirubin (TBIL) and malondialdehyde were attenuated. Ephedrine demonstrated all these identical protective effects as well. In addition, pseudoephedrine significantly suppressed the production of p-IκB-α, reducing the degradation of sequestered nuclear factor kappa B (NF-κB) in the cytoplasm, and inhibited the translocation of NF-κB/p65 to the nucleus, the transcription of TNF-α mRNA and the production of TNF-α in primary KCs. These results suggest that pseudoephedrine and ephedrine have a potent anti-inflammatory activity against D-GalN/LPS-induced acute liver failure in rats, and this comprehensive anti-inflammatory effect may result from the inhibition of TNF-α production. Copyright © 2013 Elsevier B.V. All rights reserved.

COH-203, a novel microtubule inhibitor, exhibits potent anti-tumor activity via p53-dependent senescence in hepatocellular carcinoma

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

Qi, Huan; Zuo, Dai-Ying; Bai, Zhao-Shi

Highlights: • COH-203 exhibits anti-hepatoma effects in vitro and in vivo with low toxicity. • COH-203 inhibits tubulin polymerization. • COH-203 induces mitotic arrest followed by mitotic slippage in BEL-7402 cells. • COH-203 induces p53-dependent senescence in BEL-7402 cells. - Abstract: 5-(3-Hydroxy-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-3H-1, 2-dithiol-3-one (COH-203) is a novel synthesized analogue of combretastatin A-4 that can be classified as a microtubule inhibitor. In this study, we evaluated the anti-hepatoma effect of COH-203 in vitro and in vivo and explored the underlying molecular mechanisms. COH-203 was shown to be more effective in inhibiting the proliferation of liver cancer cells compared with normal livermore » cells. COH-203 also displayed potent anti-tumor activity in a hepatocellular carcinoma xenograft model without significant toxicity. Mechanistic studies demonstrated that treatment with COH-203 induced mitotic arrest by inhibiting tubulin polymerization in BEL-7402 liver cancer cells. Long-term COH-203 treatment in BEL-7402 cells led to mitotic slippage followed by senescence via the p14{sup Arf}–p53–p21 and p16{sup INK4α}–Rb pathways. Furthermore, suppression of p53 via pifithrin-α (p53 inhibitor) and p53-siRNA attenuated COH-203-induced senescence in BEL-7402 cells, suggesting that COH-203 induced senescence p53-dependently. In conclusion, we report for the first time that COH-203, one compound in the combretastatin family, promotes anti-proliferative activity through the induction of p-53 dependent senescence. Our findings will provide a molecular rationale for the development of COH-203 as a promising anti-tumor agent.« less

Potent influenza A virus entry inhibitors targeting a conserved region of hemagglutinin.

PubMed

Lin, Dongguo; Luo, Yinzhu; Yang, Guang; Li, Fangfang; Xie, Xiangkun; Chen, Daiwei; He, Lifang; Wang, Jingyu; Ye, Chunfeng; Lu, Shengsheng; Lv, Lin; Liu, Shuwen; He, Jian

2017-11-15

Influenza A viruses (IAVs) induce acute respiratory disease and cause significant morbidity and mortality throughout the world. With the emergence of drug-resistant viral strains, new and effective anti-IAV drugs with different modes of action are urgently needed. In this study, by conjugating cholesterol to the N-terminus of the short peptide KKWK, a lipopeptide named S-KKWK was created. The anti-IAV test indicated that S-KKWK and its derivatives displayed potent antiviral activities against a broad variety of influenza A viral strains including oseltamivir-resistant strains and clinically relevant isolates with IC 50 values ranging from 0.7 to 3.0µM. An extensive mechanistic study showed that these peptides functioned as viral "entry blockers" by inhibiting the conformational rearrangements of HA2 subunit, thereby interrupting the fusion of virus-host cell membranes. Significantly, a computer-aided docking simulation and protein sequence alignment identified conserved residues in the stem region of HA2 as the possible binding site of S-KKWK, which may be employed as a potential drug target for designing anti-IAVs with a broad-spectrum of activity. By targeting this region, a potent anti-IAV agent was subsequently created. In addition, the anti-IAV activity of S-KKWK was assessed by experiments with influenza A virus-infected mice, in which S-KKWK reduced the mortality of infected animals and extended survival time significantly. Overall, in addition to providing a strategy for designing broad-spectrum anti-IAV agents, these results indicate that S-KKWK and its derivatives are prospective candidates for potent antivirals. Copyright © 2017 Elsevier Inc. All rights reserved.

Design and synthesis of potent, orally-active DGAT-1 inhibitors containing a dioxino[2,3-d]pyrimidine core.

PubMed

Dow, Robert L; Andrews, Melissa; Aspnes, Gary E; Balan, Gayatri; Michael Gibbs, E; Guzman-Perez, Angel; Karki, Kapil; Laperle, Jennifer L; Li, Jian-Cheng; Litchfield, John; Munchhof, Michael J; Perreault, Christian; Patel, Leena

2011-10-15

A novel series of potent DGAT-1 inhibitors was developed originating from the lactam-based clinical candidate PF-04620110. Incorporation of a dioxino[2,3-d]pyrimidine-based core afforded good alignment of pharmacophore features and resulted in improved passive permeability. Development of an efficient, homochiral synthesis of these targets facilitated confirmation of predictions regarding the stereochemical-dependence of DGAT-1 inhibition for this series. Compound 10 was shown to be a potent inhibitor of human DGAT-1 (10 nM) and to suppress triglyceride synthesis at oral doses of <3mg/kg. Copyright © 2011 Elsevier Ltd. All rights reserved.

Besifloxacin, a novel fluoroquinolone, has broad-spectrum in vitro activity against aerobic and anaerobic bacteria.

PubMed

Haas, Wolfgang; Pillar, Chris M; Zurenko, Gary E; Lee, Jacqueline C; Brunner, Lynne S; Morris, Timothy W

2009-08-01

The antibacterial spectrum of besifloxacin, a novel fluoroquinolone recently approved for treatment of ocular infections, was studied using 2,690 clinical isolates representing 40 species. Overall, besifloxacin was the most potent agent tested against gram-positive pathogens and anaerobes and was generally equivalent to comparator fluoroquinolones in activity against most gram-negative pathogens. Besifloxacin demonstrated potent, broad-spectrum activity, which was particularly notable against gram-positive and gram-negative isolates that were resistant to other fluoroquinolones and classes of antibacterial agents.

Synthesis and evaluation of the inhibitory activity of the four stereoisomers of the potent and selective human γ-glutamyl transpeptidase inhibitor GGsTop.

PubMed

Watanabe, Bunta; Tabuchi, Yukiko; Wada, Kei; Hiratake, Jun

2017-11-01

2-Amino-4-{[3-(carboxymethyl)phenoxy](methoxy)phosphoryl}butanoic acid (GGsTop) is a potent, highly selective, nontoxic, and irreversible inhibitor of γ-glutamyl transpeptidase (GGT). GGsTop has been widely used in academic and medicinal research, and also as an active ingredient (Nahlsgen) in commercial anti-aging cosmetics. GGsTop consists of four stereoisomers due to the presence of two stereogenic centers, i.e., the α-carbon atom of the glutamate mimic (l/d) and the phosphorus atom (R P /S P ). In this study, each stereoisomer of GGsTop was synthesized stereoselectively and their inhibitory activity against human GGT was evaluated. The l- and d-configurations of each stereoisomer were determined by a combination of a chiral pool synthesis and chiral HPLC analysis. The synthesis of the four stereoisomers of GGsTop used chiral synthetic precursors that were separated by chiral HPLC on a preparative scale. With respect to the configuration of the α-carbon atom of the glutamate mimic, the l-isomer (k on =174M -1 s -1 ) was ca. 8-fold more potent than the d-isomer (k on =21.5M -1 s -1 ). In contrast, the configuration of the phosphorus atom is critical for GGT inhibitory activity. Based on a molecular modeling approach, the absolute configuration of the phosphorus atom of the active GGsTop isomers was postulated to be S P . The S P -isomers inhibited human GGT (k on =21.5-174M -1 s -1 ), while the R P -isomers were inactive even at concentrations of 0.1mM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phosphorothioate backbone modifications of nucleotide-based drugs are potent platelet activators

PubMed Central

Flierl, Ulrike; Nero, Tracy L.; Lim, Bock; Arthur, Jane F.; Yao, Yu; Jung, Stephanie M.; Gitz, Eelo; Pollitt, Alice Y.; Zaldivia, Maria T.K.; Jandrot-Perrus, Martine; Schäfer, Andreas; Nieswandt, Bernhard; Andrews, Robert K.; Parker, Michael W.; Gardiner, Elizabeth E.

2015-01-01

Nucleotide-based drug candidates such as antisense oligonucleotides, aptamers, immunoreceptor-activating nucleotides, or (anti)microRNAs hold great therapeutic promise for many human diseases. Phosphorothioate (PS) backbone modification of nucleotide-based drugs is common practice to protect these promising drug candidates from rapid degradation by plasma and intracellular nucleases. Effects of the changes in physicochemical properties associated with PS modification on platelets have not been elucidated so far. Here we report the unexpected binding of PS-modified oligonucleotides to platelets eliciting strong platelet activation, signaling, reactive oxygen species generation, adhesion, spreading, aggregation, and thrombus formation in vitro and in vivo. Mechanistically, the platelet-specific receptor glycoprotein VI (GPVI) mediates these platelet-activating effects. Notably, platelets from GPVI function–deficient patients do not exhibit binding of PS-modified oligonucleotides, and platelet activation is fully abolished. Our data demonstrate a novel, unexpected, PS backbone–dependent, platelet-activating effect of nucleotide-based drug candidates mediated by GPVI. This unforeseen effect should be considered in the ongoing development programs for the broad range of upcoming and promising DNA/RNA therapeutics. PMID:25646267

Discovery of potent inhibitors of soluble epoxide hydrolase by combinatorial library design and structure-based virtual screening.

PubMed

Xing, Li; McDonald, Joseph J; Kolodziej, Steve A; Kurumbail, Ravi G; Williams, Jennifer M; Warren, Chad J; O'Neal, Janet M; Skepner, Jill E; Roberds, Steven L

2011-03-10

Structure-based virtual screening was applied to design combinatorial libraries to discover novel and potent soluble epoxide hydrolase (sEH) inhibitors. X-ray crystal structures revealed unique interactions for a benzoxazole template in addition to the conserved hydrogen bonds with the catalytic machinery of sEH. By exploitation of the favorable binding elements, two iterations of library design based on amide coupling were employed, guided principally by the docking results of the enumerated virtual products. Biological screening of the libraries demonstrated as high as 90% hit rate, of which over two dozen compounds were single digit nanomolar sEH inhibitors by IC(50) determination. In total the library design and synthesis produced more than 300 submicromolar sEH inhibitors. In cellular systems consistent activities were demonstrated with biochemical measurements. The SAR understanding of the benzoxazole template provides valuable insights into discovery of novel sEH inhibitors as therapeutic agents.

Synergistic anti-tumor therapy by a comb-like multifunctional antibody nanoarray with exceptionally potent activity

NASA Astrophysics Data System (ADS)

Li, Huafei; Sun, Yun; Chen, Di; Zhao, He; Zhao, Mengxin; Zhu, Xiandi; Ke, Changhong; Zhang, Ge; Jiang, Cheng; Zhang, Li; Zhang, Fulei; Wei, Huafeng; Li, Wei

2015-10-01

Simultaneously blocking multiple mediators offers new hope for the treatment of complex diseases. However, the curative potential of current combination therapy by chronological administration of separate monoclonal antibodies (mAbs) or multi-specific mAbs is still moderate due to inconvenient manipulation, low cooperative effectors, poor pharmacokinetics and insufficient tumor accumulation. Here, we describe a facile strategy that arms distinct mAbs with cooperative effectors onto a long chain to form a multicomponent comb-like nano mAb. Unlike dissociative parental mAbs, the multifunctional mAb nanoarray (PL-RB) constructed from type I/II anti-CD20 mAbs shows good pharmacokinetics. This PL-RB simultaneously targets distinct epitopes on a single antigen (Ag) and neighboring Ags on different lymphocytes. This unique intra- and intercellular Ag cross-linking endows the multifunctional mAb nanoarray with potent apoptosis activity. The exceptional apoptosis, complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) that are synchronously evoked by the nano PL-RB are further synergistically promoted via enhanced permeability and retention (EPR), which resulted in high intratumor accumulation and excellent anti-lymphoma efficiency.

Synergistic anti-tumor therapy by a comb-like multifunctional antibody nanoarray with exceptionally potent activity.

PubMed

Li, Huafei; Sun, Yun; Chen, Di; Zhao, He; Zhao, Mengxin; Zhu, Xiandi; Ke, Changhong; Zhang, Ge; Jiang, Cheng; Zhang, Li; Zhang, Fulei; Wei, Huafeng; Li, Wei

2015-10-28

Simultaneously blocking multiple mediators offers new hope for the treatment of complex diseases. However, the curative potential of current combination therapy by chronological administration of separate monoclonal antibodies (mAbs) or multi-specific mAbs is still moderate due to inconvenient manipulation, low cooperative effectors, poor pharmacokinetics and insufficient tumor accumulation. Here, we describe a facile strategy that arms distinct mAbs with cooperative effectors onto a long chain to form a multicomponent comb-like nano mAb. Unlike dissociative parental mAbs, the multifunctional mAb nanoarray (PL-RB) constructed from type I/II anti-CD20 mAbs shows good pharmacokinetics. This PL-RB simultaneously targets distinct epitopes on a single antigen (Ag) and neighboring Ags on different lymphocytes. This unique intra- and intercellular Ag cross-linking endows the multifunctional mAb nanoarray with potent apoptosis activity. The exceptional apoptosis, complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) that are synchronously evoked by the nano PL-RB are further synergistically promoted via enhanced permeability and retention (EPR), which resulted in high intratumor accumulation and excellent anti-lymphoma efficiency.

Synthetic Lethal Strategy Identifies a Potent and Selective TTK and CLK2 Inhibitor for Treatment of Triple-negative Breast Cancer with a Compromised G1/S Checkpoint.

PubMed

Zhu, Dan; Xu, Shuichan; Deyanat-Yazdi, Gordafaried; Peng, Sophie X; Barnes, Leo A; Narla, Rama Krishna; Tran, Tam; Mikolon, David; Ning, Yuhong; Shi, Tao; Jiang, Ning; Raymon, Heather K; Riggs, Jennifer R; Boylan, John F

2018-06-04

Historically, phenotypic-based drug discovery has yielded a high percentage of novel drugs while uncovering new tumor biology. CC-671 was discovered using a phenotypic screen for compounds that preferentially induced apoptosis in triple negative breast cancer cell lines while sparing luminal breast cancer cell lines. Detailed in vitro kinase profiling shows CC-671 potently and selectively inhibits two kinases-TTK and CLK2. Cellular mechanism of action studies demonstrate that CC-671 potently inhibits the phosphorylation of KNL1 and SRp75, direct TTK and CLK2 substrates, respectively. Furthermore, CC-671 causes mitotic acceleration and modification of pre-mRNA splicing leading to apoptosis, consistent with cellular TTK and CLK inhibition. Correlative analysis of genomic and potency data against a large panel of breast cancer cell lines identifies breast cancer cells with a dysfunctional G1/S checkpoint as more sensitive to CC-671, suggesting synthetic lethality between G1/S checkpoint and TTK/CLK2 inhibition. Furthermore, significant in vivo CC-671 efficacy was demonstrated in two cell line-derived and one patient tumor-derived xenograft models of TNBC following weekly dosing. These findings are the first to demonstrate the unique inhibitory combination activity of a dual TTK/CLK2 inhibitor that preferably kills TNBC cells and shows synthetic lethality with a compromised G1/S checkpoint in breast cancer cell lines. Based on these data, CC-671 was moved forward for clinical development as a potent and selective TTK/CLK2 inhibitor in a subset of TNBC patients. Copyright ©2018, American Association for Cancer Research.

Demonstrating Optical Activity Using an iPad

ERIC Educational Resources Information Center

Schwartz, Pauline M.; Lepore, Dante M.; Morneau, Brandy N.; Barratt, Carl

2011-01-01

Optical activity using an iPad as a source of polarized light is demonstrated. A sample crystal or solution can be placed on the iPad running a white screen app. The sample is viewed through a polarized filter that can be rotated. This setup can be used in the laboratory or with a document camera to easily project in a large lecture hall.…

Rigid amphipathic fusion inhibitors demonstrate antiviral activity against African swine fever virus.

PubMed

Hakobyan, Astghik; Galindo, Inmaculada; Nañez, Almudena; Arabyan, Erik; Karalyan, Zaven; Chistov, Alexey A; Streshnev, Philipp P; Korshun, Vladimir A; Alonso, Covadonga; Zakaryan, Hovakim

2018-01-01

Rigid amphipathic fusion inhibitors (RAFIs) are a family of nucleoside derivatives that inhibit the infectivity of several enveloped viruses by interacting with virion envelope lipids and inhibiting fusion between viral and cellular membranes. Here we tested the antiviral activity of two RAFIs, 5-(Perylen-3-ylethynyl)-arabino-uridine (aUY11) and 5-(Perylen-3-ylethynyl)uracil-1-acetic acid (cm1UY11) against African swine fever virus (ASFV), for which no effective vaccine is available. Both compounds displayed a potent, dose-dependent inhibitory effect on ASFV infection in Vero cells. The major antiviral effect was observed when aUY11 and cm1UY11 were added at early stages of infection and maintained during the complete viral cycle. Furthermore, virucidal assay revealed a significant extracellular anti-ASFV activity for both compounds. We also found decrease in the synthesis of early and late viral proteins in Vero cells treated with cm1UY11. Finally, the inhibitory effect of aUY11 and cm1UY11 on ASFV infection in porcine alveolar macrophages was confirmed. Overall, our study has identified novel anti-ASFV compounds with potential for future therapeutic developments.

Discovery of potent and selective small-molecule PAR-2 agonists.

PubMed

Seitzberg, Jimmi Gerner; Knapp, Anne Eeg; Lund, Birgitte Winther; Mandrup Bertozzi, Sine; Currier, Erika A; Ma, Jian-Nong; Sherbukhin, Vladimir; Burstein, Ethan S; Olsson, Roger

2008-09-25

Proteinase activated receptor-2 plays a crucial role in a wide variety of conditions with a strong inflammatory component. We present the discovery and characterization of two structurally different, potent, selective, and metabolically stable small-molecule PAR-2 agonists. These ligands may be useful as pharmacological tools for elucidating the complex physiological role of the PAR-2 receptors as well as for the development of PAR-2 antagonists.

An efficient synthesis of SK-658 and its analogs as potent histone deacetylase inhibitors.

PubMed

Shahidul Islam, Md; Nurul Islam, Md; Ashraful Hoque, Md; Nishino, Norikazu; Kato, Tamaki; Kim, Hyun-Jung; Ito, Akihiro; Yoshida, Minoru

2015-04-01

SK-658 is a potent histone deacetylase (HDAC) inhibitor that showed higher activity than SAHA due to the presence of extended hydrophobic group. We designed and synthesized thioester and SS-hybrid bearing SK-658 analogs as HDAC inhibitors. All the compounds were active in nano molar range and showed higher inhibitory activity than SAHA and SK-658. Among these, disulfide compounds showed the highest activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Classroom Activities and Demonstrations for Use in Behavioral Science Courses.

ERIC Educational Resources Information Center

Cology, Lorry J.

This compilation provides descriptions of and resource materials for 25 classroom activities or demonstrations for behavioral science courses. For each activity, the following information is provided: subject area, source, time required and materials needed. In addition, discussion questions and comments on the value and use of the activities are…

Cinnamic acid/chloroquinoline conjugates as potent agents against chloroquine-resistant Plasmodium falciparum.

PubMed

Pérez, Bianca; Teixeira, Cátia; Gut, Jiri; Rosenthal, Philip J; Gomes, José R B; Gomes, Paula

2012-09-01

Cinnamic acid derivatives containing a 4-amino-7-chloroquinoline scaffold (blue) and substituted cinnamoyl building blocks (green) linked through an alkylamine chain (red) were found to have potent (11-59 nM) in vitro activities against erythrocytic chloroquine- resistant Plasmodium falciparum. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In vivo pharmacological characterisation of bilastine, a potent and selective histamine H1 receptor antagonist.

PubMed

Corcóstegui, Reyes; Labeaga, Luis; Innerárity, Ana; Berisa, Agustín; Orjales, Aurelio

2006-01-01

We set out to establish the in vivo histamine H(1) receptor antagonistic (antihistaminic) and antiallergic properties of bilastine. In vivo antihistaminic activity experiments consisted of measurement of: inhibition of increase in capillary permeability and reduction in microvascular extravasation and bronchospasm in rats and guinea pigs induced by histamine and other inflammatory mediators; and protection against lethality induced by histamine and other inflammatory mediators in rats. In vivo antiallergic activity experiments consisted of measurement of passive and active cutaneous anaphylactic reactions as well as type III and type IV allergic reactions in sensitised rodents. In the in vivo antihistaminic activity experiments, bilastine was shown to have a positive effect, similar to that of cetirizine and more potent than that of fexofenadine. The results of the in vivo antiallergic activity experiments showed that the properties of bilastine in this setting are similar to those observed for cetirizine and superior to fexofenadine in the model of passive cutaneous anaphylactic reaction. When active cutaneous anaphylactic reaction experiments were conducted, bilastine showed significant activity, less potent than that observed with cetirizine but superior to that of fexofenadine. Evaluation of the type III allergic reaction showed that of the antihistamines only bilastine was able to inhibit oedema in sensitised mice, although its effect in this respect was much less potent than that observed with dexamethasone. In terms of the type IV allergic reaction, neither bilastine, cetirizine nor fexofenadine significantly modified the effect caused by oxazolone. The results of our in vivo preclinical studies corroborate those obtained from previously conducted in vitro experiments of bilastine, and provide evidence that bilastine possesses antihistaminic as well as antiallergic properties, with similar potency to cetirizine and superior potency to fexofenadine.

Pegylated Leptin Antagonist Is a Potent Orexigenic Agent: Preparation and Mechanism of Activity

PubMed Central

Elinav, Eran; Niv-Spector, Leonora; Katz, Meirav; Price, Tulin O.; Ali, Mohammed; Yacobovitz, Michal; Solomon, Gili; Reicher, Shay; Lynch, Jessica L.; Halpern, Zamir; Banks, William A.; Gertler, Arieh

2009-01-01

Leptin, a pleiotropic adipokine, is a central regulator of appetite and weight and a key immunomodulatory protein. Although inborn leptin deficiency causes weight gain, it is unclear whether induced leptin deficiency in adult wild-type animals would be orexigenic. Previous work with a potent competitive leptin antagonist did not induce a true metabolic state of leptin deficiency in mice because of a short circulating half-life. In this study, we increased the half-life of the leptin antagonist by pegylation, which resulted in significantly increased bioavailability and retaining of antagonistic activity. Mice administered the pegylated antagonist showed a rapid and dramatic increase in food intake with weight gain. Resulting fat was confined to the mesenteric region with no accumulation in the liver. Serum cholesterol, triglyceride, and hepatic aminotransferases remained unaffected. Weight changes were reversible on cessation of leptin antagonist treatment. The mechanism of severe central leptin deficiency was found to be primarily caused by blockade of transport of circulating leptin across the blood-brain barrier with antagonisms at the arcuate nucleus playing a more minor role. Altogether we introduce a novel compound that induces central and peripheral leptin deficiency. This compound should be useful in exploring the involvement of leptin in metabolic and immune processes and could serve as a therapeutic for the treatment of cachexia. PMID:19342450

Potent Antiarthritic Properties of Phloretin in Murine Collagen-Induced Arthritis.

PubMed

Wang, Shun-Ping; Lin, Shih-Chao; Li, Shiming; Chao, Ya-Hsuan; Hwang, Guang-Yuh; Lin, Chi-Chen

2016-01-01

In the exploration of potential therapeutic agents for rheumatoid arthritis (RA), DBA/1J mice are used as the RA model of collagen-induced arthritis (CIA). Phloretin, a flavonoid compound extracted from Prunus mandshurica , has been found to exhibit anti-inflammatory activity, making it a potential candidate for treatment of RA. The objective of this study was to evaluate the therapeutic effects of phloretin on CIA mice. CIA mice were dosed daily with phloretin at either 50 or 100 mg/kg among two treatment groups. CIA treated mice showed mitigation of clinical symptoms of RA in addition to reduced inflammation of hind-limbs compared to mice who did not receive phloretin. Histological analysis showed that phloretin suppressed the severity of RA and effectively mitigated joint inflammation and cartilage- and bone-destruction via reducing proinflammatory cytokine productions (TNF- α , IL-6, IL-1 β , and IL-17). This was at least partially mediated by causing inadequate splenocyte activation and proliferation. Moreover, phloretin-treated CIA mice showed decreased oxidative stress and diminished levels of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ) in paw tissues as well as reduced productivity of anti-collagen antibodies in serum. We have concluded that phloretin could be a potent and effective antiarthritis agent, demonstrating anti-inflammatory, antioxidative, and immunomodulatory effects in CIA mice.

Potent Elastase Inhibitors from Cyanobacteria: Structural Basis and Mechanisms Mediating Cytoprotective and Anti-inflammatory Effects in Bronchial Epithelial Cells

PubMed Central

Salvador, Lilibeth A.; Taori, Kanchan; Biggs, Jason S.; Jakoncic, Jean; Ostrov, David A.; Paul, Valerie J.; Luesch, Hendrik

2013-01-01

We discovered new structural diversity to a prevalent, yet medicinally underappreciated, cyanobacterial protease inhibitor scaffold and undertook comprehensive protease profiling to reveal potent and selective elastase inhibition. SAR and X-ray cocrystal structure analysis allowed a detailed assessment of critical and tunable structural elements. To realize the therapeutic potential of these cyclodepsipeptides, we probed the cellular effects of a novel and representative family member, symplostatin 5 (1), which attenuated the downstream cellular effects of elastase in an epithelial lung airway model system, alleviating clinical hallmarks of chronic pulmonary diseases such as cell death, cell detachment and inflammation. This compound attenuated the effects of elastase on receptor activation, proteolytic processing of the adhesion protein ICAM-1, NF-κB activation and transcriptomic changes, including the expression of pro-inflammatory cytokines IL1A, IL1B and IL8. Compound 1 exhibited activity comparable to the clinically-approved elastase inhibitor sivelestat in short-term assays and demonstrated superior sustained activity in longer-term assays. PMID:23350733

Biological evaluation of some uracil derivatives as potent glutathione reductase inhibitors

NASA Astrophysics Data System (ADS)

Güney, Murat; Ekinci, Deniz; Ćavdar, Huseyin; Şentürk, Murat; Zilbeyaz, Kani

2016-04-01

Discovery of glutathione reductase (GR) inhibitors has become very popular recently due to antimalarial and anticancer activities. In this study, GR inhibitory capacities of some uracil derivatives (UDCs) (1-4) were reported. Some commercially available molecules (5-6) were also tested for comparison reasons. The novel UDCs were obtained in high yields using simple chemical procedures and exhibited much potent inhibitory activities against GR at low nanomolar concentrations with IC50 values ranging from 2.68 to 166.6 nM as compared with well-known agents.

Structure-Based Design of Novel Dihydroalkoxybenzyloxopyrimidine Derivatives as Potent Nonnucleoside Inhibitors of the Human Immunodeficiency Virus Reverse Transcriptase

PubMed Central

Sudbeck, Elise A.; Mao, Chen; Vig, Rakesh; Venkatachalam, T. K.; Tuel-Ahlgren, Lisa; Uckun, Fatih M.

1998-01-01

Two highly potent dihydroalkoxybenzyloxopyrimidine (DABO) derivatives targeting the nonnucleoside inhibitor (NNI) binding site of human immunodeficiency virus (HIV) reverse transcriptase (RT) have been designed based on the structure of the NNI binding pocket and tested for anti-HIV activity. Our lead DABO derivative, 5-isopropyl-2-[(methylthiomethyl)thio]-6-(benzyl)-pyrimidin-4-(1H)-one, elicited potent inhibitory activity against purified recombinant HIV RT and abrogated HIV replication in peripheral blood mononuclear cells at nanomolar concentrations (50% inhibitory concentration, <1 nM) but showed no detectable cytotoxicity at concentrations as high as 100 μM. PMID:9835518

Aspartic acid based nucleoside phosphoramidate prodrugs as potent inhibitors of hepatitis C virus replication.

PubMed

Maiti, Munmun; Maiti, Mohitosh; Rozenski, Jef; De Jonghe, Steven; Herdewijn, Piet

2015-05-14

In view of a persistent threat to mankind, the development of nucleotide-based prodrugs against hepatitis C virus (HCV) is considered as a constant effort in many medicinal chemistry groups. In an attempt to identify novel nucleoside phosphoramidate analogues for improving the anti-HCV activity, we have explored, for the first time, aspartic acid (Asp) and iminodiacetic acid (IDA) esters as amidate counterparts by considering three 2'-C-methyl containing nucleosides, 2'-C-Me-cytidine, 2'-C-Me-uridine and 2'-C-Me-2'-fluoro-uridine. Synthesis of these analogues required protection for the vicinal diol functionality of the sugar moiety and the amino group of the cytidine nucleoside to regioselectively perform phosphorylation reaction at the 5'-hydroxyl group. Anti-HCV data demonstrate that the Asp-based phosphoramidates are ∼550 fold more potent than the parent nucleosides. The inhibitory activity of the Asp-ProTides was higher than the Ala-ProTides, suggesting that Asp would be a potential amino acid candidate to be considered for developing novel antiviral prodrugs.

Supramolecular assembly of multifunctional maspin-mimetic nanostructures as a potent peptide-based angiogenesis inhibitor

DOE PAGES

Zha, R. Helen; Sur, Shantanu; Boekhoven, Job; ...

2014-11-08

Aberrant angiogenesis plays a large role in pathologies ranging from tumor growth to macular degeneration. Anti-angiogenic proteins have thus come under scrutiny as versatile, potent therapeutics but face problems with purification and tissue retention. We report here on the synthesis of supramolecular nanostructures that mimic the anti-angiogenic activity of maspin, a class II tumor suppressor protein. These maspin-mimetic nanostructures are formed via self-assembly of small peptide amphiphiles containing the g-helix motif of maspin. Using tubulogenesis assays with human umbilical vein endothelial cells, we demonstrate that maspin-mimetic nanostructures show anti-angiogenic activity at concentrations that are significantly lower than those necessary formore » the g-helix peptide. Furthermore, in vivo assays in the chick chorioallantoic membrane show maspin-mimetic nanostructures to be effective over controls at inhibiting angiogenesis. Thus, in conclusion, the nanostructures investigated here offer an attractive alternative to the use of anti-angiogenic recombinant proteins in the treatment of cancer or other diseases involving abnormal blood vessel formation.« less

Discovery of potent and novel smoothened antagonists via structure-based virtual screening and biological assays.

PubMed

Lu, Wenfeng; Zhang, Dihua; Ma, Haikuo; Tian, Sheng; Zheng, Jiyue; Wang, Qin; Luo, Lusong; Zhang, Xiaohu

2018-05-23

The Hedgehog (Hh) signaling pathway plays a critical role in controlling patterning, growth and cell migration during embryonic development. Aberrant activation of Hh signaling has been linked to tumorigenesis in various cancers, such as basal cell carcinoma (BCC) and medulloblastoma. As a key member of the Hh pathway, the Smoothened (Smo) receptor, a member of the G protein-coupled receptor (GPCR) family, has emerged as an attractive therapeutic target for the treatment and prevention of human cancers. The recent determination of several crystal structures of Smo in complex with different antagonists offers the possibility to perform structure-based virtual screening for discovering potent Smo antagonists with distinct chemical scaffolds. In this study, based on the two Smo crystal complexes with the best capacity to distinguish the known Smo antagonists from decoys, the molecular docking-based virtual screening was conducted to identify promising Smo antagonists from ChemDiv library. A total of 21 structurally novel and diverse compounds were selected for experimental testing, and six of them exhibited significant inhibitory activity against the Hh pathway activation (IC 50  < 10 μM) in a GRE (Gli-responsive element) reporter gene assay. Specifically, the most potent compound (compound 20: 47 nM) showed comparable Hh signaling inhibition to vismodegib (46 nM). Compound 20 was further confirmed to be a potent Smo antagonist in a fluorescence based competitive binding assay. Optimization using substructure searching method led to the discovery of 12 analogues of compound 20 with decent Hh pathway inhibition activity, including four compounds with IC 50 lower than 1 μM. The important residues uncovered by binding free energy calculation (MM/GBSA) and binding free energy decomposition were highlighted and discussed. These findings suggest that the novel scaffold afforded by compound 20 can be used as a good starting point for further modification

Virtual screening studies to design potent CDK2-cyclin A inhibitors.

PubMed

Vadivelan, S; Sinha, Barij Nayan; Irudayam, Sheeba Jem; Jagarlapudi, Sarma A R P

2007-01-01

The cell division cycle is controlled by cyclin-dependent kinases (CDK), which consist of a catalytic subunit (CDK1-CDK8) and a regulatory subunit (cyclin A-H). Pharmacophore analysis indicates that the best inhibitor model consists of (1) two hydrogen bond acceptors, (2) one hydrogen bond donor, and (3) one hydrophobic feature. The HypoRefine pharmacophore model gave an enrichment factor of 1.31 and goodness of fit score of 0.76. Docking studies were carried out to explore the structural requirements for the CDK2-cyclin A inhibitors and to construct highly predictive models for the design of new inhibitors. Docking studies demonstrate the important role of hydrogen bond and hydrophobic interactions in determining the inhibitor-receptor binding affinity. The validated pharmacophore model is further used for retrieving the most active hits/lead from a virtual library of molecules. Subsequently, docking studies were performed on the hits, and novel series of potent leads were suggested based on the interaction energy between CDK2-cyclin A and the putative inhibitors.

Substituted N-(biphenyl-4'-yl)methyl (R)-2-acetamido-3-methoxypropionamides: potent anticonvulsants that affect frequency (use) dependence and slow inactivation of sodium channels.

PubMed

Lee, Hyosung; Park, Ki Duk; Torregrosa, Robert; Yang, Xiao-Fang; Dustrude, Erik T; Wang, Yuying; Wilson, Sarah M; Barbosa, Cindy; Xiao, Yucheng; Cummins, Theodore R; Khanna, Rajesh; Kohn, Harold

2014-07-24

We prepared 13 derivatives of N-(biphenyl-4'-yl)methyl (R)-2-acetamido-3-methoxypropionamide that differed in type and placement of a R-substituent in the terminal aryl unit. We demonstrated that the R-substituent impacted the compound's whole animal and cellular pharmacological activities. In rodents, select compounds exhibited excellent anticonvulsant activities and protective indices (PI=TD50/ED50) that compared favorably with clinical antiseizure drugs. Compounds with a polar, aprotic R-substituent potently promoted Na+ channel slow inactivation and displayed frequency (use) inhibition of Na+ currents at low micromolar concentrations. The possible advantage of affecting these two pathways to decrease neurological hyperexcitability is discussed.

Stapled α−helical peptide drug development: A potent dual inhibitor of MDM2 and MDMX for p53-dependent cancer therapy

PubMed Central

Chang, Yong S.; Graves, Bradford; Guerlavais, Vincent; Tovar, Christian; Packman, Kathryn; To, Kwong-Him; Olson, Karen A.; Kesavan, Kamala; Gangurde, Pranoti; Mukherjee, Aditi; Baker, Theresa; Darlak, Krzysztof; Elkin, Carl; Filipovic, Zoran; Qureshi, Farooq Z.; Cai, Hongliang; Berry, Pamela; Feyfant, Eric; Shi, Xiangguo E.; Horstick, James; Annis, D. Allen; Manning, Anthony M.; Fotouhi, Nader; Nash, Huw; Vassilev, Lyubomir T.; Sawyer, Tomi K.

2013-01-01

Stapled α−helical peptides have emerged as a promising new modality for a wide range of therapeutic targets. Here, we report a potent and selective dual inhibitor of MDM2 and MDMX, ATSP-7041, which effectively activates the p53 pathway in tumors in vitro and in vivo. Specifically, ATSP-7041 binds both MDM2 and MDMX with nanomolar affinities, shows submicromolar cellular activities in cancer cell lines in the presence of serum, and demonstrates highly specific, on-target mechanism of action. A high resolution (1.7-Å) X-ray crystal structure reveals its molecular interactions with the target protein MDMX, including multiple contacts with key amino acids as well as a role for the hydrocarbon staple itself in target engagement. Most importantly, ATSP-7041 demonstrates robust p53-dependent tumor growth suppression in MDM2/MDMX-overexpressing xenograft cancer models, with a high correlation to on-target pharmacodynamic activity, and possesses favorable pharmacokinetic and tissue distribution properties. Overall, ATSP-7041 demonstrates in vitro and in vivo proof-of-concept that stapled peptides can be developed as therapeutically relevant inhibitors of protein–protein interaction and may offer a viable modality for cancer therapy. PMID:23946421

Synthesis, Biological Activity, and Crystal Structure of Potent Nonnucleoside Inhibitors of HIV-1 Reverse Transcriptase That Retain Activity against Mutant Forms of the Enzyme†

PubMed Central

Morningstar, Marshall L.; Roth, Thomas; Farnsworth, David W.; Smith, Marilyn Kroeger; Watson, Karen; Buckheit, Robert W.; Das, Kalyan; Zhang, Wanyi; Arnold, Eddy; Julias, John G.; Hughes, Stephen H.; Michejda, Christopher J.

2010-01-01

In an ongoing effort to develop novel and potent nonnucleoside HIV-1 reverse transcriptase (RT) inhibitors that are effective against the wild type (WT) virus and clinically observed mutants, 1,2-bis-substituted benzimidazoles were synthesized and tested. Optimization of the N1 and C2 positions of benzimidazole led to the development of 1-(2,6-difluorobenzyl)-2-(2,6-difluorophenyl)-4-methylbenzimidazole (1) (IC50 = 0.2 μM, EC50 = 0.44 μM, and TC50 ≥ 100 against WT). This paper describes how substitution on the benzimidazole ring profoundly affects activity. Substituents at the benzimidazole C4 dramatically enhanced potency, while at C5 or C6 substituents were generally detrimental or neutral to activity, respectively. A 7-methyl analogue did not inhibit HIV-1 RT. Determination of the crystal structure of 1 bound to RT provided the basis for accurate modeling of additional analogues, which were synthesized and tested. Several derivatives were nanomolar inhibitors of wild-type virus and were effective against clinically relevant HIV-1 mutants. PMID:17663538

Discovery of Brigatinib (AP26113), a Phosphine Oxide-Containing, Potent, Orally Active Inhibitor of Anaplastic Lymphoma Kinase.

PubMed

Huang, Wei-Sheng; Liu, Shuangying; Zou, Dong; Thomas, Mathew; Wang, Yihan; Zhou, Tianjun; Romero, Jan; Kohlmann, Anna; Li, Feng; Qi, Jiwei; Cai, Lisi; Dwight, Timothy A; Xu, Yongjin; Xu, Rongsong; Dodd, Rory; Toms, Angela; Parillon, Lois; Lu, Xiaohui; Anjum, Rana; Zhang, Sen; Wang, Frank; Keats, Jeffrey; Wardwell, Scott D; Ning, Yaoyu; Xu, Qihong; Moran, Lauren E; Mohemmad, Qurish K; Jang, Hyun Gyung; Clackson, Tim; Narasimhan, Narayana I; Rivera, Victor M; Zhu, Xiaotian; Dalgarno, David; Shakespeare, William C

2016-05-26

In the treatment of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase positive (ALK+) non-small-cell lung cancer (NSCLC), secondary mutations within the ALK kinase domain have emerged as a major resistance mechanism to both first- and second-generation ALK inhibitors. This report describes the design and synthesis of a series of 2,4-diarylaminopyrimidine-based potent and selective ALK inhibitors culminating in identification of the investigational clinical candidate brigatinib. A unique structural feature of brigatinib is a phosphine oxide, an overlooked but novel hydrogen-bond acceptor that drives potency and selectivity in addition to favorable ADME properties. Brigatinib displayed low nanomolar IC50s against native ALK and all tested clinically relevant ALK mutants in both enzyme-based biochemical and cell-based viability assays and demonstrated efficacy in multiple ALK+ xenografts in mice, including Karpas-299 (anaplastic large-cell lymphomas [ALCL]) and H3122 (NSCLC). Brigatinib represents the most clinically advanced phosphine oxide-containing drug candidate to date and is currently being evaluated in a global phase 2 registration trial.

Discovery of Indazoles as Potent, Orally Active Dual Neurokinin 1 Receptor Antagonists and Serotonin Transporter Inhibitors for the Treatment of Depression.

PubMed

Degnan, Andrew P; Tora, George O; Huang, Hong; Conlon, David A; Davis, Carl D; Hanumegowda, Umesh M; Hou, Xiaoping; Hsiao, Yi; Hu, Joanna; Krause, Rudolph; Li, Yu-Wen; Newton, Amy E; Pieschl, Rick L; Raybon, Joseph; Rosner, Thorsten; Sun, Jung-Hui; Taber, Matthew T; Taylor, Sarah J; Wong, Michael K; Zhang, Huiping; Lodge, Nicholas J; Bronson, Joanne J; Macor, John E; Gillman, Kevin W

2016-12-21

Combination studies of neurokinin 1 (NK1) receptor antagonists and serotonin-selective reuptake inhibitors (SSRIs) have shown promise in preclinical models of depression. Such a combination may offer important advantages over the current standard of care. Herein we describe the discovery and optimization of an indazole-based chemotype to provide a series of potent dual NK1 receptor antagonists/serotonin transporter (SERT) inhibitors to overcome issues of ion channel blockade. This effort culminated in the identification of compound 9, an analogue that demonstrated favorable oral bioavailability, excellent brain uptake, and robust in vivo efficacy in a validated depression model. Over the course of this work, a novel heterocycle-directed asymmetric hydrogenation was developed to facilitate installation of the key stereogenic center.

Novel Bacterial Topoisomerase Inhibitors with Potent Broad-Spectrum Activity against Drug-Resistant Bacteria.

PubMed

Charrier, Cédric; Salisbury, Anne-Marie; Savage, Victoria J; Duffy, Thomas; Moyo, Emmanuel; Chaffer-Malam, Nathan; Ooi, Nicola; Newman, Rebecca; Cheung, Jonathan; Metzger, Richard; McGarry, David; Pichowicz, Mark; Sigerson, Ralph; Cooper, Ian R; Nelson, Gary; Butler, Hayley S; Craighead, Mark; Ratcliffe, Andrew J; Best, Stuart A; Stokes, Neil R

2017-05-01

The novel bacterial topoisomerase inhibitor class is an investigational type of antibacterial inhibitor of DNA gyrase and topoisomerase IV that does not have cross-resistance with the quinolones. Here, we report the evaluation of the in vitro properties of a new series of this type of small molecule. Exemplar compounds selectively and potently inhibited the catalytic activities of Escherichia coli DNA gyrase and topoisomerase IV but did not block the DNA breakage-reunion step. Compounds showed broad-spectrum inhibitory activity against a wide range of Gram-positive and Gram-negative pathogens, including biodefence microorganisms and Mycobacterium tuberculosis No cross-resistance with fluoroquinolone-resistant Staphylococcus aureus and E. coli isolates was observed. Measured MIC 90 values were 4 and 8 μg/ml against a panel of contemporary multidrug-resistant isolates of Acinetobacter baumannii and E. coli , respectively. In addition, representative compounds exhibited greater antibacterial potency than the quinolones against obligate anaerobic species. Spontaneous mutation rates were low, with frequencies of resistance typically <10 -8 against E. coli and A. baumannii at concentrations equivalent to 4-fold the MIC. Compound-resistant E. coli mutants that were isolated following serial passage were characterized by whole-genome sequencing and carried a single Arg38Leu amino acid substitution in the GyrA subunit of DNA gyrase. Preliminary in vitro safety data indicate that the series shows a promising therapeutic index and potential for low human ether-a-go-go-related gene (hERG) inhibition (50% inhibitory concentration [IC 50 ], >100 μM). In summary, the compounds' distinct mechanism of action relative to the fluoroquinolones, whole-cell potency, low potential for resistance development, and favorable in vitro safety profile warrant their continued investigation as potential broad-spectrum antibacterial agents. Copyright © 2017 American Society for Microbiology.

CT-721, a Potent Bcr-Abl Inhibitor, Exhibits Excellent In Vitro and In Vivo Efficacy in the Treatment of Chronic Myeloid Leukemia

PubMed Central

Sun, Yinghui; Zhao, Na; Wang, Huan; Wu, Qiong; Han, Yunqi; Liu, Qichao; Wu, Mangang; Liu, Yuliang; Kong, Fansheng; Wang, He; Sun, Ying; Sun, Deguang; Jing, Lutao; Tang, Guojing; Hu, Yuandong; Xiao, Dengming; Luo, Hong; Han, Yongxin; Peng, Yong

2017-01-01

Kinase inhibitors that target Bcr-Abl are highly effective in the treatment of chronic myeloid leukemia (CML). However, these inhibitors are often invalidated due to the drug resistance. Therefore, the discovery and development of novel Bcr-Abl inhibitors is required to overwhelm the drug resistance in the treatment of CML resistant to the currently used first-line Bcr-Abl inhibitors. Herein we have described a newly developed Bcr-Abl inhibitor CT-721, which displayed potent inhibitory effects on wild-type and T315I mutant Bcr-Abl. It functioned as a typically ATP-competitive inhibitor, superior to other existing Bcr-Abl inhibitors. CT-721 also demonstrated time-dependent inhibition of Bcr-Abl activation and the resultant downstream signaling transduction pathways in Bcr-Abl positive cells. Furthermore, CT-721 induced cell apoptosis and cell cycle arrest, and efficaciously inhibited tumor growth in Bcr-Abl-expressed K562 and KU812 xenograft models in a mechanism-based manner. Further PK/PD studies revealed a positive in vivo correlation between the compound concentration and inhibition of Bcr-Abl activity. Taken together, CT-721 is a potent and time-dependent Bcr-Abl kinase inhibitor, and has shown strong in vitro and in vivo anti-CML activities with a favorable pharmacokinetic profile, differentiating it from other Bcr-Abl kinase inhibitors already approved and current in development for the treatment of CML. PMID:28928866

Chlorfenapyr, a Potent Alternative Insecticide of Phoxim To Control Bradysia odoriphaga (Diptera: Sciaridae).

PubMed

Zhao, Yunhe; Wang, Qiuhong; Wang, Yao; Zhang, Zhengqun; Wei, Yan; Liu, Feng; Zhou, Chenggang; Mu, Wei

2017-07-26

Bradysia odoriphaga is the major pest affecting Chinese chive production, and in China, it has developed widespread resistance to organophosphorus insecticides. Chlorfenapyr is a promising pyrrole insecticide with a unique mechanism of action that does not confer cross-resistance to neurotoxic insecticides. However, the effect of chlorfenapyr on organophosphate-resistant B. odoriphaga is not well understood. The present study evaluated the potential of chlorfenapyr for the control of phoxim-resistant B. odoriphaga. The results showed that chlorfenapyr had significant insecticidal activity to B. odoriphaga in multiple developmental stages, and there were no significant differences in susceptibility between the field (phoxim-resistant) and laboratory (phoxim-susceptible) populations. The pot experiment and field trials confirmed the results of our laboratory bioassays. In the field trial, chlorfenapyr applied at 3.0, 6.0, or 12.0 kg of active ingredient (a.i.)/ha significantly decreased the number of B. odoriphaga and improved the yield compared to phoxim at 6.0 kg of a.i./ha and the control conditions. Moreover, the final residues of chlorfenapyr on plants were below the maximum residue limits (MRLs) as a result of its non-systemic activity. These results demonstrate that chlorfenapyr has potential as a potent alternative to phoxim for controlling B. odoriphaga.

Phosphorylation of Ser136 is critical for potent bone sialoprotein-mediated nucleation of hydroxyapatite crystals.

PubMed

Baht, Gurpreet S; O'Young, Jason; Borovina, Antonia; Chen, Hong; Tye, Coralee E; Karttunen, Mikko; Lajoie, Gilles A; Hunter, Graeme K; Goldberg, Harvey A

2010-05-27

Acidic phosphoproteins of mineralized tissues such as bone and dentin are believed to play important roles in HA (hydroxyapatite) nucleation and growth. BSP (bone sialoprotein) is the most potent known nucleator of HA, an activity that is thought to be dependent on phosphorylation of the protein. The present study identifies the role phosphate groups play in mineral formation. Recombinant BSP and peptides corresponding to residues 1-100 and 133-205 of the rat sequence were phosphorylated with CK2 (protein kinase CK2). Phosphorylation increased the nucleating activity of BSP and BSP-(133-205), but not BSP-(1-100). MS analysis revealed that the major site phosphorylated within BSP-(133-205) was Ser136, a site adjacent to the series of contiguous glutamate residues previously implicated in HA nucleation. The critical role of phosphorylated Ser136 in HA nucleation was confirmed by site-directed mutagenesis and functional analyses. Furthermore, peptides corresponding to the 133-148 sequence of rat BSP were synthesized with or without a phosphate group on Ser136. As expected, the phosphopeptide was a more potent nucleator. The mechanism of nucleation was investigated using molecular-dynamics simulations analysing BSP-(133-148) interacting with the {100} crystal face of HA. Both phosphorylated and non-phosphorylated sequences adsorbed to HA in extended conformations with alternating residues in contact with and facing away from the crystal face. However, this alternating-residue pattern was more pronounced when Ser136 was phosphorylated. These studies demonstrate a critical role for Ser136 phosphorylation in BSP-mediated HA nucleation and identify a unique mode of interaction between the nucleating site of the protein and the {100} face of HA.

Identification of new potent inhibitor of aldose reductase from Ocimum basilicum.

PubMed

Bhatti, Huma Aslam; Tehseen, Yildiz; Maryam, Kiran; Uroos, Maliha; Siddiqui, Bina S; Hameed, Abdul; Iqbal, Jamshed

2017-12-01

Recent efforts to develop cure for chronic diabetic complications have led to the discovery of potent inhibitors against aldose reductase (AKR1B1, EC 1.1.1.21) whose role in diabetes is well-evident. In the present work, two new natural products were isolated from the ariel part of Ocimum basilicum; 7-(3-hydroxypropyl)-3-methyl-8-β-O-d-glucoside-2H-chromen-2-one (1) and E-4-(6'-hydroxyhex-3'-en-1-yl)phenyl propionate (2) and confirmed their structures with different spectroscopic techniques including NMR spectroscopy etc. The isolated compounds (1, 2) were evaluated for in vitro inhibitory activity against aldose reductase (AKR1B1) and aldehyde reductase (AKR1A1). The natural product (1) showed better inhibitory activity for AKR1B1 with IC 50 value of 2.095±0.77µM compare to standard sorbinil (IC 50 =3.14±0.02µM). Moreover, the compound (1) also showed multifolds higher activity (IC 50 =0.783±0.07µM) against AKR1A1 as compared to standard valproic acid (IC 50 =57.4±0.89µM). However, the natural product (2) showed slightly lower activity for AKR1B1 (IC 50 =4.324±1.25µM). Moreover, the molecular docking studies of the potent inhibitors were also performed to identify the putative binding modes within the active site of aldose/aldehyde reductases. Copyright © 2017 Elsevier Inc. All rights reserved.

Manzamine alkaloids: isolation, cytotoxicity, antimalarial activity and SAR studies.

PubMed

Ashok, Penta; Ganguly, Swastika; Murugesan, Sankaranarayanan

2014-11-01

The infectious disease Malaria is caused by different species of the genus Plasmodium. Resistance to quinoline antimalarial drugs and decreased susceptibility to artemisinin-based combination therapy have increased the need for novel antimalarial agents. Historically, natural products have been used for the treatment of infectious diseases. Identification of natural products and their semi-synthetic derivatives with potent antimalarial activity is an important method for developing novel antimalarial agents. Manzamine alkaloids are a unique group of β-carboline alkaloids isolated from various species of marine sponge displaying potent antimalarial activity against drug-sensitive and -resistant strains of Plasmodium. In this review, we demonstrate antimalarial potency, cytotoxicity and antimalarial SAR of manzamine alkaloids. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fragment-Based Drug Discovery of Potent Protein Kinase C Iota Inhibitors.

PubMed

Kwiatkowski, Jacek; Liu, Boping; Tee, Doris Hui Ying; Chen, Guoying; Ahmad, Nur Huda Binte; Wong, Yun Xuan; Poh, Zhi Ying; Ang, Shi Hua; Tan, Eldwin Sum Wai; Ong, Esther Hq; Nurul Dinie; Poulsen, Anders; Pendharkar, Vishal; Sangthongpitag, Kanda; Lee, May Ann; Sepramaniam, Sugunavathi; Ho, Soo Yei; Cherian, Joseph; Hill, Jeffrey; Keller, Thomas H; Hung, Alvin W

2018-05-24

Protein kinase C iota (PKC-ι) is an atypical kinase implicated in the promotion of different cancer types. A biochemical screen of a fragment library has identified several hits from which an azaindole-based scaffold was chosen for optimization. Driven by a structure-activity relationship and supported by molecular modeling, a weakly bound fragment was systematically grown into a potent and selective inhibitor against PKC-ι.

The adipokine adiponectin has potent anti-fibrotic effects mediated via adenosine monophosphate-activated protein kinase: novel target for fibrosis therapy

PubMed Central

2012-01-01

Introduction Fibrosis in scleroderma is associated with collagen deposition and myofibroblast accumulation. Peroxisome proliferator activated receptor gamma (PPAR-γ), a master regulator of adipogenesis, inhibits profibrotic responses induced by transforming growth factor-ß (TGF-β), and its expression is impaired in scleroderma. The roles of adiponectin, a PPAR-γ regulated pleiotropic adipokine, in regulating the response of fibroblasts and in mediating the effects of PPAR-γ are unknown. Methods Regulation of fibrotic gene expression and TGF-ß signaling by adiponectin and adenosine monophosphate protein-activated (AMP) kinase agonists were examined in normal fibroblasts in monolayer cultures and in three-dimensional skin equivalents. AdipoR1/2 expression on skin fibroblasts was determined by real-time quantitative PCR. Results Adiponectin, an adipokine directly regulated by PPAR-γ, acts as a potent anti-fibrotic signal in normal and scleroderma fibroblasts that abrogates the stimulatory effects of diverse fibrotic stimuli and reduces elevated collagen gene expression in scleroderma fibroblasts. Adiponectin responses are mediated via AMP kinase, a fuel-sensing cellular enzyme that is necessary and sufficient for down-regulation of fibrotic genes by blocking canonical Smad signaling. Moreover, we demonstrate that endogenous adiponectin accounts, at least in part, for the anti-fibrotic effects exerted by ligands of PPAR-γ. Conclusions These findings reveal a novel link between cellular energy metabolism and extracellular matrix homeostasis converging on AMP kinase. Since the levels of adiponectin as well as its receptor are impaired in scleroderma patients with progressive fibrosis, the present results suggest a potential role for defective adiponectin expression or function in progressive fibrogenesis in scleroderma and other chronic fibrosing conditions. Restoring the adiponectin signaling axis in fibroblasts might, therefore, represent a novel

Green synthesis of silk sericin-capped silver nanoparticles and their potent anti-bacterial activity

NASA Astrophysics Data System (ADS)

Aramwit, Pornanong; Bang, Nipaporn; Ratanavaraporn, Juthamas; Ekgasit, Sanong

2014-02-01

In this study, a `green chemistry' approach was introduced to synthesize silk sericin (SS)-capped silver nanoparticles (AgNPs) under an alkaline condition (pH 11) using SS as a reducing and stabilizing agent instead of toxic chemicals. The SS-capped AgNPs were successfully synthesized at various concentrations of SS and AgNO3, but the yields were different. A higher yield of SS-capped AgNPs was obtained when the concentrations of SS and AgNO3 were increased. The SS-capped AgNPs showed a round shape and uniform size with diameter at around 48 to 117 nm. The Fourier transform infrared (FT-IR) spectroscopy result proved that the carboxylate groups obtained from alkaline degradation of SS would be a reducing agent for the generation of AgNPs while COO- and NH2 + groups stabilized the AgNPs and prevented their precipitation or aggregation. Furthermore, the SS-capped AgNPs showed potent anti-bacterial activity against various gram-positive bacteria (minimal inhibitory concentration (MIC) 0.008 mM) and gram-negative bacteria (MIC ranging from 0.001 to 0.004 mM). Therefore, the SS-capped AgNPs would be a safe candidate for anti-bacterial applications.

Tetrahydrohyperforin and Octahydrohyperforin Are Two New Potent Inhibitors of Angiogenesis

PubMed Central

Martínez-Poveda, Beatriz; Verotta, Luisella; Bombardelli, Ezio; Quesada, Ana R.; Medina, Miguel Ángel

2010-01-01

Background We have previously shown that hyperforin, a phloroglucinol derivative found in St. John's wort, behaves as a potent anti-angiogenic compound. To identify the reactive group(s) mainly involved in this anti-angiogenic effect, we have investigated the anti-angiogenic properties of a series of stable derivatives obtained by oxidative modification of the natural product. In addition, in the present work we have studied the role of the four carbonyl groups present in hyperforin by investigating the potential of some other chemically stable derivatives. Methodology/Principal Findings The experimental procedures included the analysis of the effects of treatment of endothelial cells with these compounds in cell growth, cell viability, cell migration and zymographic assays, as well as the tube formation assay on Matrigel. Our study with hyperforin and eight derivatives shows that the enolized β-dicarbonyl system contained in the structure of hyperforin has a dominant role in its antiangiogenic activity. On the other hand, two of the tested hyperforin derivatives, namely, tetrahydrohyperforin and octahydrohyperforin, behave as potent inhibitors of angiogenesis. Additional characterization of these compounds included a cell specificity study of their effects on cell growth, as well as the in vivo Matrigel plug assay. Conclusions/Significance These observations could be useful for the rational design and chemical synthesis of more effective hyperforin derivatives as anti-angiogenic drugs. Altogether, the results indicate that octahydrohyperforin is a more specific and slightly more potent antiangiogenic compound than hyperforin. PMID:20224821

Novel liver-specific cholic acid-cytarabine conjugates with potent antitumor activities: Synthesis and biological characterization

PubMed Central

Chen, Dan-qi; Wang, Xin; Chen, Lin; He, Jin-xue; Miao, Ze-hong; Shen, Jing-kang

2011-01-01

Aim: Cytarabine is an efficient anticancer agent for acute myelogenous leukemia, but with short plasma half-life and rapid deamination to its inactive metabolite. The aim of this study was to design and synthesize novel cholic acid-cytarabine conjugates to improve its pharmacokinetic parameters. Methods: The in vitro stability of novel cholic acid-cytarabine conjugates was investigated in simulated gastric and intestinal fluid, mouse blood and liver homogenate using HPLC. The portacaval samples of the conjugates were examined in male Sprague-Dawley rats using LC/MS, and in vivo distribution was examined in male Kunming mice using LC/MS. Antitumor activities were tested in HL60 cells using MTT assay. Results: Cholic acid-cytarabine compounds with four different linkers were designed and synthesized. All the four cholic acid-cytarabine conjugates could release cytarabine when incubated with the simulated gastric and intestinal fluid, mouse blood and liver homogenate. The conjugates 6, 12, and 16 were present in the portacaval samples, whereas the conjugate 7 was not detected. The conjugates 6 and 16 showed high specificity in targeting the liver (liver target index 34.9 and 16.3, respectively) and good absorption in vivo, as compared with cytarabine. In cytarabine-sensitive HL60 cells, the conjugates 6, 12, and 16 retained potent antitumor activities. Conclusion: Three novel cholic acid-cytarabine conjugates with good liver-targeting properties and absorption were obtained. Further optimization of the conjugates is needed in the future. PMID:21516131

Synthesis of (S)-(+)-decursin and its analogues as potent inhibitors of melanin formation in B16 murine melanoma cells.

PubMed

Lee, Kyeong; Lee, Jee-Hyun; Boovanahalli, Shanthaveerappa K; Choi, Yongseok; Choo, Soo-Jin; Yoo, Ick-dong; Kim, Dong Hee; Yun, Mi Young; Lee, Gye Won; Song, Gyu-Yong

2010-12-01

We report the synthesis of a novel series of highly potent melanin inhibitors which were obtained through structural modification of an anticancer compound S-(+)-decursinol. The in vitro inhibitory potencies of the newly synthesized compounds were evaluated against α-MSH induced melanin production in B16 murine melanoma cells. Among the compounds evaluated, compounds 2, 3, 6b, 7a, 7b, 8a and 8b emerged as highly potent inhibitors of melanin production. Besides, these compounds demonstrated significantly low cytotoxicity. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

GBR-12909 and fluspirilene potently inhibited binding of ( sup 3 H) (+) 3-PPP to sigma receptors in rat brain

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

Contreras, P.C.; Bremer, M.E.; Rao, T.S.

1990-01-01

Fluspirilene and GBR-12909, two compounds structurally similar to BMY-14802 and haloperidol, were assessed for their ability to interact with sigma receptors. Fluspirilene, an antipsychotic agent that interacts potently with dopamine receptors, inhibited the binding of ({sup 3}H)-(+)3-PPP (IC{sub 50} = 380 nM) more potently than rimcazole, a putative sigma antagonist that was tested clinically for antipsychotic activity. GBR-12909, a potent dopamine uptake blocker, also inhibited the binding of ({sup 3}H)-(+)3-PPP with an IC{sub 50} of 48 nM. However, other compounds that block the re-uptake of catecholamines, such as nomifensine, desipramine, imipramine, xylamine, benztropine and cocaine, were much weaker than GBR-12909asmore » sigma ligands. Thus, GBR-12909 and fluspirilene, compounds structurally similar to BMY-14802, are potent sigma ligands.« less

Clickable prodrugs bearing potent and hydrolytically cleavable nicotinamide phosphoribosyltransferase inhibitors.

PubMed

Sadrerafi, Keivan; Mason, Emilia O; Lee, Mark W

2018-01-01

Our previous study indicated that carborane containing small-molecule 1-(hydroxymethyl)-7-(4'-( trans -3″-(3'″-pyridyl)acrylamido)butyl)-1,7-dicarbadodecaborane (hm-MC4-PPEA), was a potent inhibitor of nicotinamide phosphoribosyltransferase (Nampt). Nampt has been shown to be upregulated in most cancers and is a promising target for the treatment of many different types of cancers, including breast cancers. To increase the selectivity of hm-MC4-PPEA toward cancer cells, three prodrugs were synthesized with different hydrolyzable linkers: ester, carbonate, and carbamate. Using click chemistry a fluorophore was attached to these prodrugs to act as a model for our conjugation strategy and to serve as an aid for prodrug stability studies. The stabilities of these drug conjugates were tested in phosphate-buffered saline (PBS) at normothermia (37°C) using three different pH levels, 5.5, 7.5, and 9.5, as well as in horse serum at physiological pH. The stability of each was monitored using reversed-phase HPLC equipped with both diode array and fluorescence detection. The inhibitory activity of hm-MC4-PPEA was also measured using a commercially available colorimetric assay. The biological activities of the drug conjugates as well as those of the free drug (hm-MC4-PPEA), were evaluated using the MTT assay against the human breast cancer cell lines T47D and MCF7, as well as the noncancerous, transformed, Nampt-dependent human breast epithelium cell line 184A1. hm-MC4-PPEA showed to be a potent inhibitor of recombinant Nampt activity, exhibiting an IC50 concentration of 6.8 nM. The prodrugs showed great stability towards hydrolytic degradation under neutral, mildly acidic and mildly basic conditions. The carbamate prodrug also showed to be stable in rat serum. However, the carbonate and the ester prodrug release at various rates in serum presumably owing to the presence of several different classes of esterase. The biological activities of the drug conjugates correlate

Substituted N-(Biphenyl-4′-yl)methyl (R)-2-Acetamido-3-methoxypropionamides: Potent Anticonvulsants That Affect Frequency (Use) Dependence and Slow Inactivation of Sodium Channels

PubMed Central

2015-01-01

We prepared 13 derivatives of N-(biphenyl-4′-yl)methyl (R)-2-acetamido-3-methoxypropionamide that differed in type and placement of a R-substituent in the terminal aryl unit. We demonstrated that the R-substituent impacted the compound’s whole animal and cellular pharmacological activities. In rodents, select compounds exhibited excellent anticonvulsant activities and protective indices (PI = TD50/ED50) that compared favorably with clinical antiseizure drugs. Compounds with a polar, aprotic R-substituent potently promoted Na+ channel slow inactivation and displayed frequency (use) inhibition of Na+ currents at low micromolar concentrations. The possible advantage of affecting these two pathways to decrease neurological hyperexcitability is discussed. PMID:25004277

PGH1, the Precursor for the Anti-Inflammatory Prostaglandins of the 1-series, Is a Potent Activator of the Pro-Inflammatory Receptor CRTH2/DP2

PubMed Central

Schröder, Ralf; Xue, Luzheng; Konya, Viktoria; Martini, Lene; Kampitsch, Nora; Whistler, Jennifer L.; Ulven, Trond; Heinemann, Akos; Pettipher, Roy; Kostenis, Evi

2012-01-01

Prostaglandin H1 (PGH1) is the cyclo-oxygenase metabolite of dihomo-γ-linolenic acid (DGLA) and the precursor for the 1-series of prostaglandins which are often viewed as “anti-inflammatory”. Herein we present evidence that PGH1 is a potent activator of the pro-inflammatory PGD2 receptor CRTH2, an attractive therapeutic target to treat allergic diseases such as asthma and atopic dermatitis. Non-invasive, real time dynamic mass redistribution analysis of living human CRTH2 transfectants and Ca2+ flux studies reveal that PGH1 activates CRTH2 as PGH2, PGD2 or PGD1 do. The PGH1 precursor DGLA and the other PGH1 metabolites did not display such effect. PGH1 specifically internalizes CRTH2 in stable CRTH2 transfectants as assessed by antibody feeding assays. Physiological relevance of CRTH2 ligation by PGH1 is demonstrated in several primary human hematopoietic lineages, which endogenously express CRTH2: PGH1 mediates migration of and Ca2+ flux in Th2 lymphocytes, shape change of eosinophils, and their adhesion to human pulmonary microvascular endothelial cells under physiological flow conditions. All these effects are abrogated in the presence of the CRTH2 specific antagonist TM30089. Together, our results identify PGH1 as an important lipid intermediate and novel CRTH2 agonist which may trigger CRTH2 activation in vivo in the absence of functional prostaglandin D synthase. PMID:22442685

Demonstrating Electrical Activity in Nerve and Muscle. Part I

ERIC Educational Resources Information Center

Robinson, D. J.

1975-01-01

Describes a demonstration for showing the electrical activity in nerve and muscle including action potentials, refractory period of a nerve, and fatigue. Presents instructions for constructing an amplifier, electronic stimulator, and force transducer. (GS)

In Vitro Activities of ER-119884 and E5700, Two Potent Squalene Synthase Inhibitors, against Leishmania amazonensis: Antiproliferative, Biochemical, and Ultrastructural Effects▿

PubMed Central

Fernandes Rodrigues, Juliany Cola; Concepcion, Juan Luis; Rodrigues, Carlos; Caldera, Aura; Urbina, Julio A.; de Souza, Wanderley

2008-01-01

ER-119884 and E5700, novel arylquinuclidine derivatives developed as cholesterol-lowering agents, were potent in vitro growth inhibitors of both proliferative stages of Leishmania amazonensis, the main causative agent of cutaneous leishmaniasis in South America, with the 50% inhibitory concentrations (IC50s) being in the low-nanomolar to subnanomolar range. The compounds were very potent noncompetitive inhibitors of native L. amazonensis squalene synthase (SQS), with inhibition constants also being in the nanomolar to subnanomolar range. Growth inhibition was strictly associated with the depletion of the parasite's main endogenous sterols and the concomitant accumulation of exogenous cholesterol. Using electron microscopy, we identified the intracellular structures affected by the compounds. A large number of lipid inclusions displaying different shapes and electron densities were observed after treatment with both SQS inhibitors, and these inclusions were associated with an intense disorganization of the membrane that surrounds the cell body and flagellum, as well as the endoplasmic reticulum and the Golgi complex. Cells treated with ER-119884 but not those treated with E5700 had an altered cytoskeleton organization due to an abnormal distribution of tubulin, and many were arrested at cytokinesis. A prominent contractile vacuole and a phenotype typical of programmed cell death were frequently found in drug-treated cells. The selectivity of the drugs was demonstrated with the JC-1 mitochondrial fluorescent label and by trypan blue exclusion tests with macrophages, which showed that the IC50s against the host cells were 4 to 5 orders of magnitude greater that those against the intracellular parasites. Taken together, our results show that ER-119884 and E5700 are unusually potent and selective inhibitors of the growth of Leishmania amazonensis, probably because of their inhibitory effects on de novo sterol biosynthesis at the level of SQS, but some of our

Discovery of potent broad spectrum antivirals derived from marine actinobacteria.

PubMed

Raveh, Avi; Delekta, Phillip C; Dobry, Craig J; Peng, Weiping; Schultz, Pamela J; Blakely, Pennelope K; Tai, Andrew W; Matainaho, Teatulohi; Irani, David N; Sherman, David H; Miller, David J

2013-01-01

Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable target for the

Discovery of Potent Broad Spectrum Antivirals Derived from Marine Actinobacteria

PubMed Central

Raveh, Avi; Delekta, Phillip C.; Dobry, Craig J.; Peng, Weiping; Schultz, Pamela J.; Blakely, Pennelope K.; Tai, Andrew W.; Matainaho, Teatulohi; Irani, David N.; Sherman, David H.; Miller, David J.

2013-01-01

Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable target for the

Central Limit Theorem: New SOCR Applet and Demonstration Activity

PubMed Central

Dinov, Ivo D.; Christou, Nicolas; Sanchez, Juana

2011-01-01

Modern approaches for information technology based blended education utilize a variety of novel instructional, computational and network resources. Such attempts employ technology to deliver integrated, dynamically linked, interactive content and multifaceted learning environments, which may facilitate student comprehension and information retention. In this manuscript, we describe one such innovative effort of using technological tools for improving student motivation and learning of the theory, practice and usability of the Central Limit Theorem (CLT) in probability and statistics courses. Our approach is based on harnessing the computational libraries developed by the Statistics Online Computational Resource (SOCR) to design a new interactive Java applet and a corresponding demonstration activity that illustrate the meaning and the power of the CLT. The CLT applet and activity have clear common goals; to provide graphical representation of the CLT, to improve student intuition, and to empirically validate and establish the limits of the CLT. The SOCR CLT activity consists of four experiments that demonstrate the assumptions, meaning and implications of the CLT and ties these to specific hands-on simulations. We include a number of examples illustrating the theory and applications of the CLT. Both the SOCR CLT applet and activity are freely available online to the community to test, validate and extend (Applet: http://www.socr.ucla.edu/htmls/SOCR_Experiments.html and Activity: http://wiki.stat.ucla.edu/socr/index.php/SOCR_EduMaterials_Activities_GeneralCentralLimitTheorem). PMID:21833159

Central Limit Theorem: New SOCR Applet and Demonstration Activity.

PubMed

Dinov, Ivo D; Christou, Nicolas; Sanchez, Juana

2008-07-01

Modern approaches for information technology based blended education utilize a variety of novel instructional, computational and network resources. Such attempts employ technology to deliver integrated, dynamically linked, interactive content and multifaceted learning environments, which may facilitate student comprehension and information retention. In this manuscript, we describe one such innovative effort of using technological tools for improving student motivation and learning of the theory, practice and usability of the Central Limit Theorem (CLT) in probability and statistics courses. Our approach is based on harnessing the computational libraries developed by the Statistics Online Computational Resource (SOCR) to design a new interactive Java applet and a corresponding demonstration activity that illustrate the meaning and the power of the CLT. The CLT applet and activity have clear common goals; to provide graphical representation of the CLT, to improve student intuition, and to empirically validate and establish the limits of the CLT. The SOCR CLT activity consists of four experiments that demonstrate the assumptions, meaning and implications of the CLT and ties these to specific hands-on simulations. We include a number of examples illustrating the theory and applications of the CLT. Both the SOCR CLT applet and activity are freely available online to the community to test, validate and extend (Applet: http://www.socr.ucla.edu/htmls/SOCR_Experiments.html and Activity: http://wiki.stat.ucla.edu/socr/index.php/SOCR_EduMaterials_Activities_GeneralCentralLimitTheorem).

Design, synthesis and biological evaluation of bisthiazole-based trifluoromethyl ketone derivatives as potent HDAC inhibitors with improved cellular efficacy.

PubMed

Gong, Chao-Jun; Gao, An-Hui; Zhang, Yang-Ming; Su, Ming-Bo; Chen, Fei; Sheng, Li; Zhou, Yu-Bo; Li, Jing-Ya; Li, Jia; Nan, Fa-Jun

2016-04-13

Histone deacetylases (HDACs) are a class of epigenetic modulators with complex functions in histone post-translational modifications and are well known targets for antineoplastic drugs. We have previously developed a series of bisthiazole-based hydroxamic acids as novel potent HDAC inhibitors. In the present work, a new series of bisthiazole-based compounds with different zinc binding groups (ZBGs) have been designed and synthesized. Among them is compound 7, containing a trifluoromethyl ketone as the ZBG, which displays potent inhibitory activity towards human HDACs and improved antiproliferative activity in several cancer cell lines. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Design, synthesis and evaluation of rivastigmine and curcumin hybrids as site-activated multitarget-directed ligands for Alzheimer's disease therapy.

PubMed

Li, Yujie; Peng, Peng; Tang, Li; Hu, Yunzhen; Hu, Yongzhou; Sheng, Rong

2014-09-01

A series of novel 2-methoxy-phenyl dimethyl-carbamate derivatives were designed, synthesized and evaluated as site-activated MTDLs based on rivastigmine and curcumin. Most of them exhibited good to excellent AChE and BuChE inhibitory activities with sub-micromolar IC50 values. Among all the compounds, 6a demonstrated the most potent AChE inhibition with IC50 value of 0.097μM, which is about 20-fold than that of rivastigmine. In addition, the three selected compounds 5a, 6a and 6e demonstrated inhibitory activity against Aβ self-aggregation similar to cucurmin in TEM assay, which is obviously different from the weak activity of rivastigmine. Moreover, the hydrolysate of 6a (compound 7) also showed potent ABTS(+) scavenging and moderate copper ion chelating activity in vitro. Copyright © 2014 Elsevier Ltd. All rights reserved.

Candidacidal activity of synthetic peptides based on the antimicrobial domain of the neutrophil-derived protein, CAP37

PubMed Central

Pereira, H. Anne; Tsyshevskaya-Hoover, Irina; Hinsley, Heather; Logan, Sreemathi; Nguyen, Melissa; Nguyen, Thuy-Trang; Pohl, Jan; Wozniak, Karen; Fidel, Paul L.

2009-01-01

The primary bactericidal domain of CAP37, a cationic antimicrobial protein with potent activity against Gram-negative organisms was previously shown to reside between amino acids 20 through 44 (NQGRHFCGGALIHARFVMTAASCFQ) of the native protein. In this study, we explored the efficacy of four synthetic CAP37 peptide analogs, based on this sequence, against various Candida species including fluconazole-sensitive and -resistant isolates of C. albicans. Three of the peptides demonstrated strong antifungal activity for C. albicans, including fluconazole-resistant isolates of C. albicans and were active against C. guilliermondii, C. tropicalis, C. pseudotropicalis, C. parapsilosis, and C. dubliniensis. The peptides were ineffective against C. glabrata, C. krusei, and Saccharomyces cerevisiae. For C. albicans isolates, the peptides had relatively greater activity against blastoconidia than hyphal forms, although strong antifungal activity was observed with pseudohyphal forms of the various Candida species tested. Kinetic studies demonstrated fungicidal rather than fungistatic activity. These findings indicate that synthetic peptides based on the antimicrobial domain of CAP37 also have activity against eukaryotic organisms suggesting a broader range of activity than originally demonstrated and show for the first time their potent fungicidal activity. PMID:19626550

Characterizations of a synthetic pituitary adenylate cyclase-activating polypeptide analog displaying potent neuroprotective activity and reduced in vivo cardiovascular side effects in a Parkinson's disease model.

PubMed

Lamine, Asma; Létourneau, Myriam; Doan, Ngoc Duc; Maucotel, Julie; Couvineau, Alain; Vaudry, Hubert; Chatenet, David; Vaudry, David; Fournier, Alain

2016-09-01

Parkinson's disease (PD) is characterized by a steady loss of dopamine neurons through apoptotic, inflammatory and oxidative stress processes. In that line of view, the pituitary adenylate cyclase-activating polypeptide (PACAP), with its ability to cross the blood-brain barrier and its anti-apoptotic, anti-inflammatory and anti-oxidative properties, has proven to offer potent neuroprotection in various PD models. Nonetheless, its peripheral actions, paired with low metabolic stability, hampered its clinical use. We have developed Ac-[Phe(pI)(6), Nle(17)]PACAP(1-27) as an improved PACAP-derived neuroprotective compound. In vitro, this analog stimulated cAMP production, maintained mitochondrial potential and protected SH-SY5Y neuroblastoma cells from 1-methyl-4-phenylpyridinium (MPP(+)) toxicity, as potently as PACAP. Furthermore, contrasting with PACAP, it is stable in human plasma and against dipeptidyl peptidase IV activity. When injected intravenously to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, PACAP and Ac-[Phe(pI)(6), Nle(17)]PACAP(1-27) restored tyrosine hydoxylase expression into the substantia nigra and modulated the inflammatory response. Albeit falls of mean arterial pressure (MAP) were observed with both PACAP- and Ac-[Phe(pI)(6), Nle(17)]PACAP(1-27)-treated mice, the intensity of the decrease as well as its duration were significantly less marked after iv injections of the analog than after those of the native polypeptide. Moreover, no significant changes in heart rate were measured with the animals for both compounds. Thus, Ac-[Phe(pI)(6), Nle(17)]PACAP(1-27) appears as a promising lead molecule for the development of PACAP-derived drugs potentially useful for the treatment of PD or other neurodegenerative diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification of β-Amino alcohol grafted 1,4,5 trisubstituted 1,2,3-triazoles as potent antimalarial agents.

PubMed

Devender, Nalmala; Gunjan, Sarika; Chhabra, Stuti; Singh, Kartikey; Pasam, Venkata Reddy; Shukla, Sanjeev K; Sharma, Abhisheak; Jaiswal, Swati; Singh, Sunil Kumar; Kumar, Yogesh; Lal, Jawahar; Trivedi, Arun Kumar; Tripathi, Renu; Tripathi, Rama Pati

2016-02-15

In a quest to discover new drugs, we have synthesized a series of novel β-amino alcohol grafted 1,2,3-triazoles and screened them for their in vitro antiplasmodial and in vivo antimalarial activity. Among them, compounds 16 and 25 showed potent activity against chloroquine-sensitive (Pf3D7) strain with IC50 of 0.87 and 0.3 μM respectively, while compounds 7 and 13 exhibited better activity in vitro than the reference drug against chloroquine-resistance strain (PfK1) with IC50 of 0.5 μM each. Compound 25 showed 86.8% in vivo antimalarial efficacy with favorable pharmacokinetic parameters. Mechanistic studies divulged that potent compounds significantly boosted p53 protein levels to exhibit the antimalarial activity. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The two novel DLL4-targeting antibody-drug conjugates MvM03 and MGD03 show potent anti-tumour activity in breast cancer xenograft models.

PubMed

Wang, Shijing; Zhou, Rihong; Sun, Fumou; Li, Renjie; Wang, Min; Wu, Min

2017-11-28

The anti-human Delta-like 4 (DLL4) monoclonal antibody MMGZ01 has a high affinity to hrDLL4 and arrests the DLL4-mediated human umbilical vein endothelial cell (HUVEC) phenotype, promotes immature vessels, and effectively reduces breast cancer cell growth in vivo. To develop a much more effective therapy, we conjugated MMGZ01 with two small-molecule cytotoxic agents, i.e., monomethyl auristatin E (MMAE) and doxorubicin (DOX), with different linkers to generate antibody-drug conjugates (ADCs), i.e., MMGZ01-vc-MMAE (named MvM03) and MMGZ01-GMBS-DOX (named MGD03), that are more potent therapeutic agents than naked antibody therapeutic agents. The produced anti-DLL4 ADCs can be effectively directed against DLL4 and internalized. Then, the release of MMAE or DOX into the cytosol can induce G2/M or G0/G1 phase growth arrest and cell death through the induction of apoptosis. In vitro, MvM03 was highly potent and selective against DLL4 cell lines. The anti-DLL4 ADCs, particularly MvM03, showed more potent anti-tumour activity than Docetaxel, which is an inhibitor of the depolymerisation of microtubules, in two xenograft breast cancer tumour models. Our findings indicate that anti-DLL4 ADCs have promising potential as an effective therapy for breast cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Efforts towards the optimization of a bi-aryl class of potent IRAK4 inhibitors

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

Hanisak, Jennifer; Seganish, W. Michael; McElroy, William T.

2016-09-01

IRAK4 has been identified as potential therapeutic target for inflammatory and autoimmune diseases. Herein we report the identification and initial SAR studies of a new class of pyrazole containing IRAK4 inhibitors designed to expand chemical diversity and improve off target activity of a previously identified series. These compounds maintain potent IRAK4 activity and desirable ligand efficiency. Rat clearance and a variety of off target activities were also examined, resulting in encouraging data with tractable SAR.

Discovery of potent and selective CDK8 inhibitors through FBDD approach.

PubMed

Han, Xingchun; Jiang, Min; Zhou, Chengang; Zhou, Zheng; Xu, Zhiheng; Wang, Lisha; Mayweg, Alexander V; Niu, Rui; Jin, Tai-Guang; Yang, Song

2017-09-15

A fragment library screen was carried out to identify starting points for novel CDK8 inhibitors. Optimization of a fragment hit guided by co-crystal structures led to identification of a novel series of potent CDK8 inhibitors which are highly ligand efficient, kinase selective and cellular active. Compound 16 was progressed to a mouse pharmacokinetic study and showed good oral bioavailability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Essential oil of Artemisia vestita exhibits potent in vitro and in vivo antibacterial activity: Investigation of the effect of oil on biofilm formation, leakage of potassium ions and survival curve measurement

PubMed Central

YANG, CHANG; HU, DONG-HUI; FENG, YAN

2015-01-01

The aim of the present study was to investigate the chemical composition of the essential oil of Artemisia vestita and to determine the antibacterial activity of the essential oil and its two major components, grandisol and 1,8-cineole, against certain respiratory infection-causing bacterial strains, in vitro and in vivo. The chemical composition of the essential oil was analyzed using gas chromatography-mass spectrometry. A micro-well dilution method was used to determine the minimum inhibition concentration (MIC) values of the essential oil and its major constituents. A model of Streptococcus pyogenes infection in mice was used to determine its in vivo activities. Lung and blood samples were obtained to assess bacterial cell counts. Toxicity evaluation of the essential oil and its components was completed by performing biochemical analysis of the serum, particularly monitoring aspartate transaminase, alanine transaminase, urea and creatinine. The essential oil exhibited potent antibacterial activity, whereas the two major constituents were less potent. The essential oil exhibited MIC values between 20 and 80 μg/ml, while the values of the two constituents were between 130 and 200 μg/ml. Scanning electron microscopy results demonstrated that the essential oil inhibited biofilm formation and altered its architecture. Survival curves indicated that the essential oil led to a reduction in the viability of different bacteria. The essential oil also induced significant leakage of potassium ions from S. pyogenes. The essential oil (100 μg/mouse) and grandisol (135 μg/mouse) significantly reduced the number of viable bacterial cells in the lungs (P<0.01). However, intake of 100 μg/mouse of essential oil or grandisol 135 μg/mouse once or twice each day for 9 days did not produce any toxic effects in the mice. In conclusion, the in vitro and in vivo results suggested that the essential oil of A. vestita and one of its major constituents, grandisol, can significantly

Essential oil of Artemisia vestita exhibits potent in vitro and in vivo antibacterial activity: Investigation of the effect of oil on biofilm formation, leakage of potassium ions and survival curve measurement.

PubMed

Yang, Chang; Hu, Dong-Hui; Feng, Yan

2015-10-01

The aim of the present study was to investigate the chemical composition of the essential oil of Artemisia vestita and to determine the antibacterial activity of the essential oil and its two major components, grandisol and 1,8‑cineole, against certain respiratory infection‑causing bacterial strains, in vitro and in vivo. The chemical composition of the essential oil was analyzed using gas chromatography‑mass spectrometry. A micro‑well dilution method was used to determine the minimum inhibition concentration (MIC) values of the essential oil and its major constituents. A model of Streptococcus pyogenes infection in mice was used to determine its in vivo activities. Lung and blood samples were obtained to assess bacterial cell counts. Toxicity evaluation of the essential oil and its components was completed by performing biochemical analysis of the serum, particularly monitoring aspartate transaminase, alanine transaminase, urea and creatinine. The essential oil exhibited potent antibacterial activity, whereas the two major constituents were less potent. The essential oil exhibited MIC values between 20 and 80 µg/ml, while the values of the two constituents were between 130 and 200 µg/ml. Scanning electron microscopy results demonstrated that the essential oil inhibited biofilm formation and altered its architecture. Survival curves indicated that the essential oil led to a reduction in the viability of different bacteria. The essential oil also induced significant leakage of potassium ions from S. pyogenes. The essential oil (100 µg/mouse) and grandisol (135 µg/mouse) significantly reduced the number of viable bacterial cells in the lungs (P<0.01). However, intake of 100 µg/mouse of essential oil or grandisol 135 µg/mouse once or twice each day for 9 days did not produce any toxic effects in the mice. In conclusion, the in vitro and in vivo results suggested that the essential oil of A. vestita and one of its major constituents, grandisol, can

JS-K has Potent Anti-Angiogenic Activity in vitro and Inhibits Tumor Angiogenesis in a Multiple Myeloma Model in vivo

PubMed Central

Kaur, Gurmeet; Kiziltepe, Tanyel; Anderson, Kenneth C.; Kutok, Jeffery L.; Jia, Lee; Boucher, Kenneth M.; Saavedra, Joseph E.; Keefer, Larry K.; Shami, Paul J.

2009-01-01

Glutathione S-Transferases (GST) play an important role in multidrug resistance and are upregulated in multiple cancers. We have designed a prodrug class that releases NO on metabolism by GST. O2-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent anti-neoplastic activity. We studied the effect of JS-K on angiogenesis. JS-K inhibited the proliferation of HUVEC’s with a 50% inhibitory concentration (IC50) of 0.432, 0.466, and 0.505 µM at 24, 48, and 72 hours, respectively. In the cord formation assay, JS-K led to a decrease in the number of cord junctions and cord length with an IC50 of 0.637 and 0.696 µM, respectively. JS-K inhibited cell migration at 5 hours using VEGF as a chemoattractant. Migration inhibition occurred with an IC50 of 0.493 µM. In the chick aortic ring assay using VEGF or FGF-b for vessel growth stimulation, 0.5 µM JS-K completely inhibited vessel growth. JS-K inhibited tumor angiogenesis in vivo in NIH III mice implanted subcutaneously with OPM1 multiple myeloma cells. JS-K is a potent inhibitor of angiogenesis in vitro and tumor vessel growth in vivo. As such, it establishes a new class of anti-neoplastic agents that target the malignant cells directly as well as their microenvironment. PMID:20723011

2',5'-Dihydroxychalcone as a potent chemical mediator and cyclooxygenase inhibitor.

PubMed

Lin, C N; Lee, T H; Hsu, M F; Wang, J P; Ko, F N; Teng, C M

1997-05-01

Eleven chalcone derivatives have been tested for their inhibitory effects on platelet aggregation in rabbit platelet suspension and the activation of mast cells and neutrophils. Arachidonic acid-induced platelet aggregation was potently inhibited by almost all the compounds and some also had a potent inhibitory effect on collagen-induced platelet aggregation and cyclooxygenase. Some hydroxychalcone derivatives showed strong inhibitory effects on the release of beta-glucuronidase and lysozyme, and on superoxide formation by rat neutrophils stimulated with the peptide fMet-Leu-Phe (fMLP). We found that the anti-inflammatory effect of 2',5'-dihydroxychalcone was greater than that of trifluoperazine. 2'5'-Dihydroxy and 2',3,4,5'-tetrahydroxyl chalcones, even at low concentration (50 microM), tested in platelet-rich plasma from man almost completely inhibited secondary aggregation induced by adrenaline. These results suggest that the anti-platelet effects of the chalcones are mainly a result of inhibition of thromboxane formation.

Citrus fruit and fabacea secondary metabolites potently and selectively block TRPM3

PubMed Central

Straub, I; Mohr, F; Stab, J; Konrad, M; Philipp, SE; Oberwinkler, J; Schaefer, M

2013-01-01

Background and Purpose The melastatin-related transient receptor potential TRPM3 is a calcium-permeable nonselective cation channel that can be activated by the neurosteroid pregnenolone sulphate (PregS) and heat. TRPM3-deficient mice show an impaired perception of noxious heat. Hence, drugs inhibiting TRPM3 possibly get in focus of analgesic therapy. Experimental Approach Fluorometric methods were used to identify novel TRPM3-blocking compounds and to characterize their potency and selectivity to block TRPM3 but not other sensory TRP channels. Biophysical properties of the block were assessed using electrophysiological methods. Single cell calcium measurements confirmed the block of endogenously expressed TRPM3 channels in rat and mouse dorsal root ganglion (DRG) neurones. Key Results By screening a compound library, we identified three natural compounds as potent blockers of TRPM3. Naringenin and hesperetin belong to the citrus fruit flavanones, and ononetin is a deoxybenzoin. Eriodictyol, a metabolite of naringenin and hesperetin, was still biologically active as a TRPM3 blocker. The compounds exhibited a marked specificity for recombinant TRPM3 and blocked PregS-induced [Ca2+]i signals in freshly isolated DRG neurones. Conclusion and Implications The data indicate that citrus fruit flavonoids are potent and selective blockers of TRPM3. Their potencies ranged from upper nanomolar to lower micromolar concentrations. Since physiological functions of TRPM3 channels are still poorly defined, the development and validation of potent and selective blockers is expected to contribute to clarifying the role of TRPM3 in vivo. Considering the involvement of TRPM3 in nociception, TRPM3 blockers may represent a novel concept for analgesic treatment. PMID:23190005

Citrus fruit and fabacea secondary metabolites potently and selectively block TRPM3.

PubMed

Straub, I; Mohr, F; Stab, J; Konrad, M; Philipp, S E; Oberwinkler, J; Schaefer, M

2013-04-01

The melastatin-related transient receptor potential TRPM3 is a calcium-permeable nonselective cation channel that can be activated by the neurosteroid pregnenolone sulphate (PregS) and heat. TRPM3-deficient mice show an impaired perception of noxious heat. Hence, drugs inhibiting TRPM3 possibly get in focus of analgesic therapy. Fluorometric methods were used to identify novel TRPM3-blocking compounds and to characterize their potency and selectivity to block TRPM3 but not other sensory TRP channels. Biophysical properties of the block were assessed using electrophysiological methods. Single cell calcium measurements confirmed the block of endogenously expressed TRPM3 channels in rat and mouse dorsal root ganglion (DRG) neurones. By screening a compound library, we identified three natural compounds as potent blockers of TRPM3. Naringenin and hesperetin belong to the citrus fruit flavanones, and ononetin is a deoxybenzoin. Eriodictyol, a metabolite of naringenin and hesperetin, was still biologically active as a TRPM3 blocker. The compounds exhibited a marked specificity for recombinant TRPM3 and blocked PregS-induced [Ca(2+)]i signals in freshly isolated DRG neurones. The data indicate that citrus fruit flavonoids are potent and selective blockers of TRPM3. Their potencies ranged from upper nanomolar to lower micromolar concentrations. Since physiological functions of TRPM3 channels are still poorly defined, the development and validation of potent and selective blockers is expected to contribute to clarifying the role of TRPM3 in vivo. Considering the involvement of TRPM3 in nociception, TRPM3 blockers may represent a novel concept for analgesic treatment. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

Lentin, a novel and potent antifungal protein from shitake mushroom with inhibitory effects on activity of human immunodeficiency virus-1 reverse transcriptase and proliferation of leukemia cells.

PubMed

Ngai, Patrick H K; Ng, T B

2003-11-14

From the fruiting bodies of the edible mushroom Lentinus edodes, a novel protein designated lentin with potent antifungal activity was isolated. Lentin was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and Mono S. The N-terminal sequence of lentin manifested similarity to endoglucanase. Lentin, which had a molecular mass of 27.5 kDa, inhibited mycelial growth in a variety of fungal species including Physalospora piricola, Botrytis cinerea and Mycosphaerella arachidicola. Lentin also exerted an inhibitory activity on HIV-1 reverse transcriptase and proliferation of leukemia cells.

Design, synthesis and biological evaluation of pyrazolylaminoquinazoline derivatives as highly potent pan-fibroblast growth factor receptor inhibitors.

PubMed

Fan, Jun; Dai, Yang; Shao, Jingwei; Peng, Xia; Wang, Chen; Cao, Sufen; Zhao, Bin; Ai, Jing; Geng, Meiyu; Duan, Wenhu

2016-06-01

Fibroblast growth factor receptors (FGFRs) are important oncology targets due to the dysregulation of this signaling pathway in a wide variety of human cancers. We identified a series of pyrazolylaminoquinazoline derivatives as potent FGFR inhibitors with low nanomolar potency. The representative compound 29 strongly inhibited FGFR1-3 kinase activity and suppressed FGFR signaling transduction in FGFR-addicted cancer cells; FGFRs-driven cell proliferation was also strongly inhibited regardless of mechanistic complexity implicated in FGFR activation, which further confirmed that 29 was a potent pan-FGFR inhibitor. The flexibility of our structure offered the potential to preserve good affinity for mutant FGFR, which is important for developing TKIs with long-term efficacy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Interactive lecture demonstrations, active learning, and the ALOP project

NASA Astrophysics Data System (ADS)

Lakshminarayanan, Vasudevan

2011-05-01

There is considerable evidence from the physics education literature that traditional approaches are ineffective in teaching physics concepts. A better teaching method is to use the active learning environment, which can be created using interactive lecture demonstrations. Based on the active learning methodology and within the framework of the UNESCO mandate in physics education and introductory physics, the ALOP project (active learning in optics and photonics) was started in 2003, to provide a focus on an experimental area that is adaptable and relevant to research and educational conditions in many developing countries. This project is discussed in this paper.

An Activity for Demonstrating the Concept of a Neural Circuit

ERIC Educational Resources Information Center

Kreiner, David S.

2012-01-01

College students in two sections of a general psychology course participated in a demonstration of a simple neural circuit. The activity was based on a neural circuit that Jeffress proposed for localizing sounds. Students in one section responded to a questionnaire prior to participating in the activity, while students in the other section…

Microwave-assisted synthesis and tyrosinase inhibitory activity of chalcone derivatives.

PubMed

Liu, Jinbing; Chen, Changhong; Wu, Fengyan; Zhao, Liangzhong

2013-07-01

A series of chalcones and their derivatives were synthesized, and their inhibitory effects on the diphenolase activity of mushroom tyrosinase were evaluated. The results showed that some of the synthesized compounds exhibited significant inhibitory activity, and four compounds exhibited more potent tyrosinase inhibitory activity than the reference standard inhibitor kojic acid (5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one). Specifically, 1-(-1-(4-methoxyphen- yl)-3-phenylallylidene)thiosemicarbazide (18) exhibited the most potent tyrosinase inhibitory activity with IC₅₀ value of 0.274 μM. The inhibition mechanism analysis of 1-(-1-(2,4-dihydroxyphenyl)-3-phenylallylidene) thiosemicarbazide (16) and 1-(-1-(4-methoxyphenyl)-3-phenylallylidene) thiosemicarbazide (18) demonstrated that the inhibitory effects of the two compounds on the tyrosinase were irreversible. Preliminary structure activity relationships' analysis suggested that further development of such compounds might be of interest. © 2013 John Wiley & Sons A/S.

Honaucins A–C, Potent Inhibitors of Eukaryotic Inflammation and Bacterial Quorum Sensing: Synthetic Derivatives and Structure-Activity Relationships

PubMed Central

Choi, Hyukjae; Mascuch, Samantha J.; Villa, Francisco A.; Byrum, Tara; Teasdale, Margaret E.; Smith, Jennifer E.; Preskitt, Linda B.; Rowley, David C.; Gerwick, Lena; Gerwick, William H.

2012-01-01

SUMMARY Honaucins A–C were isolated from the cyanobacterium Leptolyngbya crossbyana which was found overgrowing corals on the Hawaiian coast. Honaucin A consists of (S)-3-hydroxy-γ-butyrolactone and 4-chlorocrotonic acid which are connected via an ester linkage. Honaucin A and its two natural analogs exhibit potent inhibition of bioluminescence, a quorum sensing-dependent phenotype, in Vibrio harveyi BB120 as well as of lipopolysaccharide-stimulated nitric oxide production in the murine macrophage cell line RAW264.7. The decrease in nitric oxide production was accompanied by a decrease in the transcripts of several pro-inflammatory cytokines, most dramatically interleukin-1β. Synthesis of honaucin A as well as a number of analogs and subsequent evaluation in anti-inflammation and quorum sensing inhibition bioassays revealed the essential structural features for activity in this chemical class, and provided analogs with greater potency in both assays. PMID:22633410

Discovery, synthesis, selectivity modulation and DMPK characterization of 5-azaspiro[2.4]heptanes as potent orexin receptor antagonists.

PubMed

Stasi, Luigi Piero; Artusi, Roberto; Bovino, Clara; Buzzi, Benedetta; Canciani, Luca; Caselli, Gianfranco; Colace, Fabrizio; Garofalo, Paolo; Giambuzzi, Silvia; Larger, Patrice; Letari, Ornella; Mandelli, Stefano; Perugini, Lorenzo; Pucci, Sabrina; Salvi, Matteo; Toro, PierLuigi

2013-05-01

Starting from a orexin 1 receptor selective antagonist 4,4-disubstituted piperidine series a novel potent 5-azaspiro[2.4]heptane dual orexin 1 and orexin 2 receptor antagonist class has been discovered. SAR and Pharmacokinetic optimization of this series is herein disclosed. Lead compound 15 exhibits potent activity against orexin 1 and orexin 2 receptors along with low cytochrome P450 inhibition potential, good brain penetration and oral bioavailability in rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mesoionic pyrido[1,2-a]pyrimidinones: Discovery of triflumezopyrim as a potent hopper insecticide1.

PubMed

Zhang, Wenming; Holyoke, Caleb W; Pahutski, Thomas F; Lahm, George P; Barry, James D; Cordova, Daniel; Leighty, Robert M; Singh, Vineet; Vicent, Daniel R; Tong, My-Hanh T; Hughes, Kenneth A; McCann, Stephen F; Henry, Yewande T; Xu, Ming; Briddell, Twyla A

2017-01-01

A novel class of mesoionic pyrido[1,2-a]pyrimidinones has been discovered with exceptional insecticidal activity controlling a number of insect species. In this communication, we report the part of the optimization program which led to the discovery of triflumezopyrim as a highly potent insecticide controlling various hopper species. Our efforts in discovery, synthesis, structure-activity relationship elucidation, and biological activity evaluation are also presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

BRP-187: A potent inhibitor of leukotriene biosynthesis that acts through impeding the dynamic 5-lipoxygenase/5-lipoxygenase-activating protein (FLAP) complex assembly.

PubMed

Garscha, Ulrike; Voelker, Susanna; Pace, Simona; Gerstmeier, Jana; Emini, Besa; Liening, Stefanie; Rossi, Antonietta; Weinigel, Christina; Rummler, Silke; Schubert, Ulrich S; Scriba, Gerhard K E; Çelikoğlu, Erşan; Çalışkan, Burcu; Banoglu, Erden; Sautebin, Lidia; Werz, Oliver

2016-11-01

The pro-inflammatory leukotrienes (LTs) are formed from arachidonic acid (AA) in activated leukocytes, where 5-lipoxygenase (5-LO) translocates to the nuclear envelope to assemble a functional complex with the integral nuclear membrane protein 5-LO-activating protein (FLAP). FLAP, a MAPEG family member, facilitates AA transfer to 5-LO for efficient conversion, and LT biosynthesis critically depends on FLAP. Here we show that the novel LT biosynthesis inhibitor BRP-187 prevents the 5-LO/FLAP interaction at the nuclear envelope of human leukocytes without blocking 5-LO nuclear redistribution. BRP-187 inhibited 5-LO product formation in human monocytes and polymorphonuclear leukocytes stimulated by lipopolysaccharide plus N-formyl-methionyl-leucyl-phenylalanine (IC 50 =7-10nM), and upon activation by ionophore A23187 (IC 50 =10-60nM). Excess of exogenous AA markedly impaired the potency of BRP-187. Direct 5-LO inhibition in cell-free assays was evident only at >35-fold higher concentrations, which was reversible and not improved under reducing conditions. BRP-187 prevented A23187-induced 5-LO/FLAP complex assembly in leukocytes but failed to block 5-LO nuclear translocation, features that were shared with the FLAP inhibitor MK886. Whereas AA release, cyclooxygenases and related LOs were unaffected, BRP-187 also potently inhibited microsomal prostaglandin E 2 synthase-1 (IC 50 =0.2μM), another MAPEG member. In vivo, BRP-187 (10mg/kg) exhibited significant effectiveness in zymosan-induced murine peritonitis, suppressing LT levels in peritoneal exudates as well as vascular permeability and neutrophil infiltration. Together, BRP-187 potently inhibits LT biosynthesis in vitro and in vivo, which seemingly is caused by preventing the 5-LO/FLAP complex assembly and warrants further preclinical evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

The pharmacological profile of CGP 28238, a novel highly potent anti-inflammatory compound.

PubMed

Wiesenberg-Boettcher, I; Schweizer, A; Green, J R; Mueller, K; Maerki, F; Pfeilschifter, J

1989-01-01

CGP 28238 (6-(2,4-difluorophenoxy)-5-methylsulfonylamino-1-indanone ) exhibits very potent anti-inflammatory activity in rat adjuvant arthritis (ED40 = 0.05 mg/kg, p.o.) and pronounced analgesic and antipyretic activity in acute models in mice and rats (ED50 2-5 mg/kg, p.o.), but has clear advantages over reference NSAIDs with respect to gastro-intestinal tolerability. Threshold doses for gastro-intestinal ulcerogenicity in rats after single and repeated (10x) doses were found to be 30 mg/kg, p.o., and prostaglandin (PGE2) production in rat gastric and ileal mucosa was only marginally inhibited (ED50 greater than 30 mg/kg, p.o.). On the other hand, PGE2 production in rat inflammatory exudate and thromboxane synthesis in rat blood were inhibited with ED50 values of less than or equal to 2 mg/kg, p.o. Although CGP28238 does not inhibit cyclooxygenase in bovine seminal vesicle microsomal preparations (IC50 greater than 10(-3) mol/l), potent inhibition of prostaglandin synthesis was shown in various in vitro systems using human and animal cells with IC50 values of less than 10(-6) mol/l. IL-1-stimulated bone resorption and PGE2 production in murine calvarial cultures were inhibited with IC50 values of 3 x 10(-7) and 2 x 10(-8) mol/l, respectively. 5-Lipoxygenase (murine macrophages), phospholipase A2 (human PMN) and phospholipase C (human platelets) were not inhibited. CGP 28238 may represent a novel highly potent anti-inflammatory compound with improved gastro-intestinal safety.

Characterization of the Binding of a Potent Synthetic Androgen, Methyltrienolone, to Human Tissues

PubMed Central

Menon, Mani; Tananis, Catherine E.; Hicks, L. Louise; Hawkins, Edward F.; McLoughlin, Martin G.; Walsh, Patrick C.

1978-01-01

The potent synthetic androgen methytrienolone (R 1881), which does not bind to serum proteins, was utilized to characterize binding to receptors in human androgen responsive tissues. Cytosol extracts prepared from hypertrophic prostates (BPH) were utilized as the source of receptor for the initial studies. High affinity binding was detected in the cytosol of 29 of 30 samples of BPH (average number of binding sites, 45.8±4.7 fmol/mg of protein; dissociation constant, 0.9±0.2 nM). This binding had the characteristics of a receptor: heat lability, precipitability by 0-33% ammonium sulfate and by protamine sulfate, and 8S sedimentation coefficient. High affinity binding was also detected in cytosol prepared from seminal vesicle, epididymis, and genital skin but not in non-genital skin or muscle. However, similar binding was demonstrated in the cytosol of human uterus. The steroid specificities of binding to the cytosol of male tissues of accessory reproduction and of uterus were similar in that progestational agents were more effective competitors than natural androgens. Binding specificities in cytosol prepared from genital skin were distinctly different and were similar to those of ventral prostate from the castrated rat in that dihydrotestosterone was much more potent than progestins in competition. Thus binding of R 1881 to the cytosol of prostate, epididymis, and seminal vesicle has some characteristics of binding to a progesterone receptor. When the nuclear extract from BPH was analyzed, high affinity binding was demonstrated that conformed to the specificities of binding to an androgen receptor. Here dihydrotestosterone was a more potent competitor than progestational agents. Similar patterns of binding were detected in the crude nuclear extracts from seminal vesicle, epididymis, and genital skin but not in uterus, muscle, or non-genital skin. We conclude that the androgen receptor is not demonstrable in the cytosol of prostate, epididymis, or seminal vesicle

Berberine potentizes apoptosis induced by X-rays irradiation probably through modulation of gap junctions.

PubMed

Liu, Bing; Wang, Qin; Yuan, Dong-dong; Hong, Xiao-ting; Tao, Liang

2011-04-01

Clinical combination of some traditional Chinese medical herbs, including berberine, with irradiation is demonstrated to improve efficacy of tumor radiotherapy, yet the mechanisms for such effect remain largely unknown. The present study investigated the effect of berberine on apoptosis induced by X-rays irradiation and the relation between this effect and gap junction intercellular communication (GJIC). The role of gap junctions in the modulation of X-rays irradiation-induced apoptosis was explored by manipulation of connexin (Cx) expression, and gap junction function, using oleamide, a GJIC inhibitor, and berberine. In transfected HeLa cells, Cx32 expression increased apoptosis induced by X-rays irradiation, while inhibition of gap junction by oleamide reduced the irradiation responses, indicating the dependence of X-rays irradiation-induced apoptosis on GJIC. Berberine, at the concentrations without cytotoxicity, enhanced apoptosis induced by irradiation only in the presence of functional gap junctions. These results suggest that berberine potentizes cell apoptosis induced by X-rays irradiation, probably through enhancement of gap junction activity.

The anti-papillomavirus activity of human and bovine lactoferricin.

PubMed

Mistry, Nitesh; Drobni, Peter; Näslund, Jonas; Sunkari, Vivekananda Gupta; Jenssen, Håvard; Evander, Magnus

2007-09-01

Human papillomavirus (HPV) cause common warts, laryngeal papilloma and genital condylomata and is necessary for the development of cervical cancer. We have previously found that lactoferrin has antiviral activity against HPV-16 and others have demonstrated that lactoferricin, an N-terminal fragment of lactoferrin, has inhibitory activities against several viruses. Two cell lines and two virus types, HPV-5 and HPV-16, were used to study if lactoferrin and lactoferricin could inhibit HPV pseudovirus (PsV) infection. We demonstrated that bovine lactoferrin (bLf) and human lactoferrin (hLf) were both potent inhibitors of HPV-5 and -16 PsV infections. Among the four lactoferricin derivatives we analyzed, a 15 amino acid peptide from bovine lactoferricin (bLfcin) 17-31 was the most potent inhibitor of both HPV-5 and HPV-16 PsV infection. Among the other derivatives, the human lactoferricin (hLfcin) 1-49 showed some antiviral activity against HPV PsV infection while bLfcin 17-42 inhibited only HPV-5 PsV infection in one of the cell lines. When we studied initial attachment of HPV-16, only bLfcin 17-42 and hLfcin 1-49 had an antiviral effect. This is the first time that lactoferricin was demonstrated to have an inhibitory effect on HPV infection and the antiviral activity differed depending on size, charge and structures of the lactoferricin.

Theonellamide G, a potent antifungal and cytotoxic bicyclic glycopeptide from the Red Sea marine sponge Theonella swinhoei.

PubMed

Youssef, Diaa T A; Shaala, Lamiaa A; Mohamed, Gamal A; Badr, Jihan M; Bamanie, Faida H; Ibrahim, Sabrin R M

2014-04-01

In our search for bioactive metabolites from marine organisms, we have investigated the polar fraction of the organic extract of the Red Sea sponge Theonella swinhoei. Successive chromatographic separations and final HPLC purification of the potent antifungal fraction afforded a new bicyclic glycopeptide, theonellamide G. The structure of the peptide was determined using extensive 1D and 2D NMR and high-resolution mass spectral determinations. The absolute configuration of theonellamide G was determined by chemical degradation and 2D NMR spectroscopy. Theonellamide G showed potent antifungal activity towards wild and amphotericin B-resistant strains of Candida albicans with IC₅₀ of 4.49 and 2.0 μM, respectively. Additionally, it displayed cytotoxic activity against the human colon adenocarcinoma cell line (HCT-16) with IC₅₀ of 6.0 μM. These findings provide further insight into the chemical diversity and biological activities of this class of compounds.

Highly sensitive luciferase reporter assay using a potent destabilization sequence of calpain 3.

PubMed

Yasunaga, Mayu; Murotomi, Kazutoshi; Abe, Hiroko; Yamazaki, Tomomi; Nishii, Shigeaki; Ohbayashi, Tetsuya; Oshimura, Mitsuo; Noguchi, Takako; Niwa, Kazuki; Ohmiya, Yoshihiro; Nakajima, Yoshihiro

2015-01-20

Reporter assays that use luciferases are widely employed for monitoring cellular events associated with gene expression in vitro and in vivo. To improve the response of the luciferase reporter to acute changes of gene expression, a destabilization sequence is frequently used to reduce the stability of luciferase protein in the cells, which results in an increase of sensitivity of the luciferase reporter assay. In this study, we identified a potent destabilization sequence (referred to as the C9 fragment) consisting of 42 amino acid residues from human calpain 3 (CAPN3). Whereas the half-life of Emerald Luc (ELuc) from the Brazilian click beetle Pyrearinus termitilluminans was reduced by fusing PEST (t1/2=9.8 to 2.8h), the half-life of C9-fused ELuc was significantly shorter (t1/2=1.0h) than that of PEST-fused ELuc when measurements were conducted at 37°C. In addition, firefly luciferase (luc2) was also markedly destabilized by the C9 fragment compared with the humanized PEST sequence. These results indicate that the C9 fragment from CAPN3 is a much more potent destabilization sequence than the PEST sequence. Furthermore, real-time bioluminescence recording of the activation kinetics of nuclear factor-κB after transient treatment with tumor necrosis factor α revealed that the response of C9-fused ELuc is significantly greater than that of PEST-fused ELuc, demonstrating that the use of the C9 fragment realizes a luciferase reporter assay that has faster response speed compared with that provided by the PEST sequence. Copyright © 2014 Elsevier B.V. All rights reserved.

Soluble GARP has potent antiinflammatory and immunomodulatory impact on human CD4⁺ T cells.

PubMed

Hahn, Susanne A; Stahl, Heiko F; Becker, Christian; Correll, Anita; Schneider, Franz-Joseph; Tuettenberg, Andrea; Jonuleit, Helmut

2013-08-15

Glycoprotein A repetitions predominant (GARP) is expressed on the surface of activated human regulatory T cells (Treg) and regulates the bioavailability of transforming growth factor-β (TGF-β). GARP has been assumed to require membrane anchoring. To investigate the function of GARP in more detail, we generated a soluble GARP protein (sGARP) and analyzed its impact on differentiation and activation of human CD4⁺ T cells. We demonstrate that sGARP efficiently represses proliferation and differentiation of naïve CD4⁺ T cells into T effector cells. Exposure to sGARP induces Foxp3, decreases proliferation and represses interleukin (IL)-2 and interferon-γ production, resulting in differentiation of naïve T cells into induced Treg. This is associated with Smad2/3 phosphorylation and partially inhibited by blockade of TGF-β signaling. Furthermore, in the presence of the proinflammatory cytokines IL-6 and IL-23, sGARP facilitates the differentiation of naïve T cells into Th17 cells. More important, in a preclinical humanized mouse model of xenogeneic graft-versus-host disease (GVHD), sGARP prevents T cell-mediated destructive inflammation by enhancing Treg and inhibiting T effector cell activity. These results demonstrate a crucial role of sGARP in modulation of peripheral tolerance and T effector cell function, opening the possibility to use sGARP as a potent immunomodulator of inflammatory diseases including transplant rejection, autoimmunity, and allergy.

One-dimensional poly(L-lysine)-block-poly(L-threonine) assemblies exhibit potent anticancer activity by enhancing membranolysis.

PubMed

Chen, Yu-Fon; Shiau, Ai-Li; Chang, Sue-Joan; Fan, Nai-Shin; Wang, Chung-Teng; Wu, Chao-Liang; Jan, Jeng-Shiung

2017-06-01

Herein, we report the oncolytic activity of cationic, one-dimensional (1D) fibril assemblies formed from coil-sheet poly(L-lysine)-block-poly(L-threonine) (PLL-b-PLT) block copolypeptides for cancer therapy. The 1D fibril assemblies can efficiently interact with negatively charged cellular and mitochondrial membranes via electrostatic interactions, leading to necrosis via membrane lysis and apoptosis via the mitochondria-lytic effect. The concept is analogous to that of 1D drug carriers that exhibit enhanced cell penetration. In comparison to free PLL chains, PLL-b-PLT fibril assemblies exhibit selective cytotoxicity toward cancer cells, low hemolysis activity, enhanced membranolytic activity, and a different apoptosis pathway, which may be due to differences in the peptide-membrane interactions. Antitumor studies using a metastatic LL2 lung carcinoma model indicate that the fibril assemblies significantly inhibited tumor growth, improved survival in tumor-bearing mice and suppressed lung metastasis without obvious body weight loss. An additive efficacy was also observed for treatment with both PLL-b-PLT and cisplatin. These results support the feasibility of using 1D fibril assemblies as potential apoptotic anticancer therapeutics. We report that cationic, one-dimensional (1D) fibril assemblies formed by coil-sheet poly(L-lysine)-block-poly(L-threonine) (PLL-b-PLT) block copolypeptides exhibited potent anticancer activity by enhancing membranolysis. The 1D fibril assemblies can efficiently interact with negatively charged cellular and mitochondrial membranes via electrostatic interactions, leading to necrosis via membrane lysis and apoptosis via mitochondria-lytic effect. Moreover, the fibril assemblies exhibited low hemolytic activity and selective cytotoxicity toward cancer cell, which is advantageous as compared to PLL and most antimicrobial/anticancerous peptides. This study provides a new concept of using cationic, 1D fibril assemblies for cancer therapy

Synthesis and SAR studies of very potent imidazopyridine antiprotozoal agents.

PubMed

Biftu, Tesfaye; Feng, Dennis; Fisher, Michael; Liang, Gui-Bai; Qian, Xiaoxia; Scribner, Andrew; Dennis, Richard; Lee, Shuliang; Liberator, Paul A; Brown, Chris; Gurnett, Anne; Leavitt, Penny S; Thompson, Donald; Mathew, John; Misura, Andrew; Samaras, Samantha; Tamas, Tamas; Sina, Joseph F; McNulty, Kathleen A; McKnight, Crystal G; Schmatz, Dennis M; Wyvratt, Matthew

2006-05-01

Compounds 10a (IC50 110 pM) and 21 (IC50 40 pM) are the most potent inhibitors of Eimeria tenella cGMP-dependent protein kinase activity reported to date and are efficacious in the in vivo antiparasitic assay when administered to chickens at 12.5 and 6.25 ppm levels in the feed. However, both compounds are positive in the Ames microbial mutagenesis assay which precludes them from further development as antiprotozoal agents in the absence of negative lifetime rodent carcinogenicity studies.

A selective and potent CXCR3 antagonist SCH 546738 attenuates the development of autoimmune diseases and delays graft rejection

PubMed Central

2012-01-01

Background The CXCR3 receptor and its three interferon-inducible ligands (CXCL9, CXCL10 and CXCL11) have been implicated as playing a central role in directing a Th1 inflammatory response. Recent studies strongly support that the CXCR3 receptor is a very attractive therapeutic target for treating autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis and psoriasis, and to prevent transplant rejection. We describe here the in vitro and in vivo pharmacological characterizations of a novel and potent small molecule CXCR3 antagonist, SCH 546738. Results In this study, we evaluated in vitro pharmacological properties of SCH 546738 by radioligand receptor binding and human activated T cell chemotaxis assays. In vivo efficacy of SCH 546738 was determined by mouse collagen-induced arthritis, rat and mouse experimental autoimmune encephalomyelitis, and rat cardiac transplantation models. We show that SCH 546738 binds to human CXCR3 with a high affinity of 0.4 nM. In addition, SCH 546738 displaces radiolabeled CXCL10 and CXCL11 from human CXCR3 with IC50 ranging from 0.8 to 2.2 nM in a non-competitive manner. SCH 546738 potently and specifically inhibits CXCR3-mediated chemotaxis in human activated T cells with IC90 about 10 nM. SCH 546738 attenuates the disease development in mouse collagen-induced arthritis model. SCH 546738 also significantly reduces disease severity in rat and mouse experimental autoimmune encephalomyelitis models. Furthermore, SCH 546738 alone achieves dose-dependent prolongation of rat cardiac allograft survival. Most significantly, SCH 546738 in combination with CsA supports permanent engraftment. Conclusions SCH 546738 is a novel, potent and non-competitive small molecule CXCR3 antagonist. It is efficacious in multiple preclinical disease models. These results demonstrate that therapy with CXCR3 antagonists may serve as a new strategy for treatment of autoimmune diseases, including rheumatoid arthritis and multiple sclerosis, and to

N-acetyl-cysteine exhibits potent anti-mycobacterial activity in addition to its known anti-oxidative functions.

PubMed

Amaral, Eduardo P; Conceição, Elisabete L; Costa, Diego L; Rocha, Michael S; Marinho, Jamocyr M; Cordeiro-Santos, Marcelo; D'Império-Lima, Maria Regina; Barbosa, Theolis; Sher, Alan; Andrade, Bruno B

2016-10-28

Mycobacterium tuberculosis infection is thought to induce oxidative stress. N-acetyl-cysteine (NAC) is widely used in patients with chronic pulmonary diseases including tuberculosis due to its mucolytic and anti-oxidant activities. Here, we tested whether NAC exerts a direct antibiotic activity against mycobacteria. Oxidative stress status in plasma was compared between pulmonary TB (PTB) patients and those with latent M. tuberculosis infection (LTBI) or healthy uninfected individuals. Lipid peroxidation, DNA oxidation and cell death, as well as accumulation of reactive oxygen species (ROS) were measured in cultures of primary human monocyte-derived macrophages infected with M. tuberculosis and treated or not with NAC. M. tuberculosis, M. avium and M. bovis BCG cultures were also exposed to different doses of NAC with or without medium pH adjustment to control for acidity. The anti-mycobacterial effect of NAC was assessed in M. tuberculosis infected human THP-1 cells and bone marrow-derived macrophages from mice lacking a fully functional NADPH oxidase system. The capacity of NAC to control M. tuberculosis infection was further tested in vivo in a mouse (C57BL/6) model. PTB patients exhibited elevated levels of oxidation products and a reduction of anti-oxidants compared with LTBI cases or uninfected controls. NAC treatment in M. tuberculosis-infected human macrophages resulted in a decrease of oxidative stress and cell death evoked by mycobacteria. Importantly, we observed a dose-dependent reduction in metabolic activity and in vitro growth of NAC treated M. tuberculosis, M. avium and M. bovis BCG. Furthermore, anti-mycobacterial activity in infected macrophages was shown to be independent of the effects of NAC on the host NADPH oxidase system in vitro. Short-term NAC treatment of M. tuberculosis infected mice in vivo resulted in a significant reduction of mycobacterial loads in the lungs. NAC exhibits potent anti-mycobacterial effects and may limit M

Synthesis and biological evaluation of novel thiadiazole amides as potent Cdc25B and PTP1B inhibitors.

PubMed

Li, Yingjun; Yu, Yang; Jin, Kun; Gao, Lixin; Luo, Tongchuan; Sheng, Li; Shao, Xin; Li, Jia

2014-09-01

A series of novel thiadiazole amide derivatives have been synthesized and evaluated for inhibitory activities against Cdc25B and PTP1B. Most of them showed inhibitory activities against Cdc25B (IC50=1.18-8.01 μg/mL) and PTP1B (IC50=0.85-8.75 μg/mL), respectively. Moreover, compounds 5b and 4l were most potent with IC50 values of 1.18 and 0.85 μg/mL for Cdc25B and PTP1B, respectively, compared with reference drugs Na3VO4 (IC50=0.93 μg/mL) and oleanolic acid (IC50=0.85 μg/mL). The results of selectivity experiments showed that the target compounds were selective inhibitors against PTP1B and Cdc25B. Enzyme kinetic experiments demonstrated that compound 5k was a specific inhibitor with the typical characteristics of a mixed inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

Potent inhibitory effect of silibinin from milk thistle on skin inflammation stimuli by 12-O-tetradecanoylphorbol-13-acetate.

PubMed

Liu, Wenfeng; Li, Yonglian; Zheng, Xi; Zhang, Kun; Du, Zhiyun

2015-12-01

Silibinin, a major polyphenol in milk thistle, has been reported to have multiple pharmacological activities; therefore, there is an urgent need to well understand how silibinin works on inflammation-associated skin diseases. We herein designed silibinin on 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated skin inflammation to test its inhibitory effects. It was demonstrated that silibinin, applied topically onto mouse ears following TPA stimulation, effectively down-regulated the expressions of TPA-induced interleukin-1β (IL-1β), interleukin-6 (IL-6), necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2) in a dose-dependent manner. Further mechanistic investigations indicated that silibinin suppressed the expression of IκB kinase (IKK) by inhibiting the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway, and thereby suppressing TPA-stimulated nuclear factor-κB (NF-κB) activation. Promisingly, silibinin, used for transdermal application, may be a potent naturally occurring anti-inflammatory agent for the prevention of inflammation-associated skin diseases.

Fused heterocycles bearing bridgehead nitrogen as potent HIV-1 NNRTIs. Part 3: optimization of [1,2,4]triazolo[1,5-a]pyrimidine core via structure-based and physicochemical property-driven approaches.

PubMed

Huang, Boshi; Li, Cuicui; Chen, Wenmin; Liu, Tao; Yu, Mingyan; Fu, Lu; Sun, Yueyue; Liu, Huiqing; De Clercq, Erik; Pannecouque, Christophe; Balzarini, Jan; Zhan, Peng; Liu, Xinyong

2015-03-06

In our arduous efforts to develop new potent HIV-1 non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs), novel piperidine-linked [1,2,4]triazolo[1,5-a]pyrimidine derivatives were designed, synthesized and evaluated for their antiviral activities in MT-4 cell cultures. Biological results showed that all of the title compounds displayed moderate to excellent activities against wild-type (wt) HIV-1 strain (IIIB) with EC50 values ranging from 8.1 nM to 2284 nM in a cell-based assay. Among them, the most promising analog 7d possessed an EC50 value of 8.1 nM against wt HIV-1, which was much more potent than the reference drugs DDI, 3 TC, NVP and DLV. Additionally, 7d demonstrated weak activity against the double mutant HIV-1 strain (K103N + Y181C), and was more efficient than NVP in a RT inhibition assay. Besides, some measured and calculated physicochemical properties of 7d, like log P and water solubility, as well as the structure-activity relationships (SARs) analysis have been discussed in detail. Furthermore, the binding mode of the active compound 7d was rationalized by molecular simulation studies. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Development of a new benzophenone-diketopiperazine-type potent antimicrotubule agent possessing a 2-pyridine structure.

PubMed

Hayashi, Yoshiki; Takeno, Haruka; Chinen, Takumi; Muguruma, Kyohei; Okuyama, Kohei; Taguchi, Akihiro; Takayama, Kentaro; Yakushiji, Fumika; Miura, Masahiko; Usui, Takeo; Hayashi, Yoshio

2014-10-09

A new benzophenone-diketopiperazine-type potent antimicrotubule agent was developed by modifying the structure of the clinical candidate plinabulin (1). Although the right-hand imidazole ring with a branched alkyl chain at the 5-position in 1 was critical for the potency of the antimicrotubule activity, we successfully substituted this moiety with a simpler 2-pyridyl structure by converting the left-hand ring from a phenyl to a benzophenone structure without decreasing the potency. The resultant compound 6b (KPU-300) exhibited a potent cytotoxicity, with an IC50 value of 7.0 nM against HT-29 cells, by strongly binding to tubulin (K d = 1.3 μM) and inducing microtubule depolymerization.

Ophiamides A-B, new potent urease inhibitory sphingolipids from Heliotropium ophioglossum.

PubMed

Firdous, Sadiqa; Ansari, Nida Hassan; Fatima, Itrat; Malik, Abdul; Afza, Nighat; Iqbal, Lubna; Lateef, Mehreen

2012-07-01

Ophiamides A (1) and B (2), two new sphingolipids have been isolated from the n-hexane subfraction of the MeOH extract of the whole plant of Heliotropium ophioglossum along with glycerol monopalmitate (3) and β-sitosterol 3-O-β-D: -glucoside (4) reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS and 2D-NMR spectroscopy. Both the compounds 1 and 2 showed potent inhibitory activity against the enzyme urease.

TS-071 is a novel, potent and selective renal sodium-glucose cotransporter 2 (SGLT2) inhibitor with anti-hyperglycaemic activity.

PubMed

Yamamoto, K; Uchida, S; Kitano, K; Fukuhara, N; Okumura-Kitajima, L; Gunji, E; Kozakai, A; Tomoike, H; Kojima, N; Asami, J; Toyoda, H; Arai, M; Takahashi, T; Takahashi, K

2011-09-01

The renal sodium-glucose cotransporter 2 (SGLT2) plays an important role in the reuptake of filtered glucose in the proximal tubule and therefore may be an attractive target for the treatment of diabetes mellitus. This study characterizes the pharmacological profile of TS-071 ((1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol hydrate), a novel SGLT2 inhibitor in vitro and in vivo. Inhibition of glucose uptake by TS-071 was studied in CHO-K1 cells stably expressing either human SGLT1 or SGLT2. Single oral dosing studies were performed in rats, mice and dogs to assess the abilities of TS-071 to increase urinary glucose excretion and to lower plasma glucose levels. TS-071 inhibited SGLT2 activity in a concentration-dependent manner and was a potent and highly selective inhibitor of SGLT2. Orally administered TS-071 increased urinary glucose excretion in Zucker fatty rats and beagle dogs at doses of 0.3 and 0.03 mg·kg(-1) respectively. TS-071 improved glucose tolerance in Zucker fatty rats without stimulating insulin secretion and reduced hyperglycaemia in streptozotocin (STZ)-induced diabetic rats and db/db mice at a dose of 0.3 mg·kg(-1). These data indicate that TS-071 is a potent and selective SGLT2 inhibitor that improves glucose levels in rodent models of type 1 and 2 diabetes and may be useful for the treatment for diabetes mellitus. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

JS-K has potent anti-angiogenic activity in vitro and inhibits tumour angiogenesis in a multiple myeloma model in vivo.

PubMed

Kiziltepe, Tanyel; Anderson, Kenneth C; Kutok, Jeffery L; Jia, Lee; Boucher, Kenneth M; Saavedra, Joseph E; Keefer, Larry K; Shami, Paul J

2010-01-01

Glutathione S-transferases (GSTs) play an important role in multidrug resistance and are upregulated in multiple cancers. We have designed a prodrug class that releases nitric oxide on metabolism by GST. O(2)-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent antineoplastic activity. We studied the effect of JS-K on angiogenesis in human umbilical vein endothelial cells (HUVECs), OPM1 multiple myeloma cells, chick aortic rings and in mice. JS-K inhibited the proliferation of HUVECs with a 50% inhibitory concentration (IC50) of 0.432, 0.466 and 0.505 microm at 24, 48 and 72 h, respectively. In the cord formation assay, JS-K led to a decrease in the number of cord junctions and cord length with an IC50 of 0.637 and 0.696 microm, respectively. JS-K inhibited cell migration at 5 h using VEGF as a chemoattractant. Migration inhibition occurred with an IC50 of 0.493 microm. In the chick aortic ring assay using VEGF or FGF-2 for vessel growth stimulation, 0.5 microm JS-K completely inhibited vessel growth. JS-K inhibited tumour angiogenesis in vivo in NIH III mice implanted subcutaneously with OPM1 multiple myeloma cells. JS-K is a potent inhibitor of angiogenesis in vitro and tumour vessel growth in vivo. As such, it establishes a new class of antineoplastic agent that targets the malignant cells directly as well as their microenvironment.

Exploring pharmacological activities and signaling of morphinans substituted in position 6 as potent agonists interacting with the μ opioid receptor

PubMed Central

2014-01-01

Background Opioid analgesics are the most effective drugs for the treatment of moderate to severe pain. However, they also produce several adverse effects that can complicate pain management. The μ opioid (MOP) receptor, a G protein-coupled receptor, is recognized as the opioid receptor type which primarily mediates the pharmacological actions of clinically used opioid agonists. The morphinan class of analgesics including morphine and oxycodone are of main importance as therapeutically valuable drugs. Though the natural alkaloid morphine contains a C-6-hydroxyl group and the semisynthetic derivative oxycodone has a 6-carbonyl function, chemical approaches have uncovered that functionalizing position 6 gives rise to a range of diverse activities. Hence, position 6 of N-methylmorphinans is one of the most manipulated sites, and is established to play a key role in ligand binding at the MOP receptor, efficacy, signaling, and analgesic potency. We have earlier reported on a chemically innovative modification in oxycodone resulting in novel morphinans with 6-acrylonitrile incorporated substructures. Results This study describes in vitro and in vivo pharmacological activities and signaling of new morphinans substituted in position 6 with acrylonitrile and amido functions as potent agonists and antinociceptive agents interacting with MOP receptors. We show that the presence of a 6-cyano group in N-methylmorphinans has a strong influence on the binding to the opioid receptors and post-receptor signaling. One 6-cyano-N-methylmorphinan of the series was identified as the highest affinity and most selective MOP agonist, and very potent in stimulating G protein coupling and intracellular calcium release through the MOP receptor. In vivo, this MOP agonist showed to be greatly effective against thermal and chemical nociception in mice with marked increased antinociceptive potency than the lead molecule oxycodone. Conclusion Development of such novel chemotypes by targeting

Discovery of a potent and orally available acyl-CoA: cholesterol acyltransferase inhibitor as an anti-atherosclerotic agent: (4-phenylcoumarin)acetanilide derivatives.

PubMed

Ogino, Masaki; Fukui, Seiji; Nakada, Yoshihisa; Tokunoh, Ryosuke; Itokawa, Shigekazu; Kakoi, Yuichi; Nishimura, Satoshi; Sanada, Tsukasa; Fuse, Hiromitsu; Kubo, Kazuki; Wada, Takeo; Marui, Shogo

2011-01-01

Acyl-CoA: cholesterol acyltransferase (ACAT) is an intracellular enzyme that catalyzes cholesterol esterification. ACAT inhibitors are expected to be potent therapeutic agents for the treatment of atherosclerosis. A series of potent ACAT inhibitors based on an (4-phenylcoumarin)acetanilide scaffold was identified. Evaluation of the structure-activity relationships of a substituent on this scaffold, with an emphasis on improving the pharmacokinetic profile led to the discovery of 2-[7-chloro-4-(3-chlorophenyl)-6-methyl-2-oxo-2H-chromen-3-yl]-N-[4-chloro-2-(trifluoromethyl)phenyl]acetamide (23), which exhibited potent ACAT inhibitory activity (IC50=12 nM) and good pharmacokinetic profile in mice. Compound 23 also showed regressive effects on atherosclerotic plaques in apolipoprotein (apo)E knock out (KO) mice at a dose of 0.3 mg/kg per os (p.o.).

A Classroom Demonstration of Rayleigh Light Scattering in Optically Active and Inactive Systems.

ERIC Educational Resources Information Center

Pecina, Monica Avalos; Smith, Charles A.

1999-01-01

Argues that the concept of optical activity is vague to students because it is difficult for instructors to demonstrate the phenomenon in the classroom. Presents a demonstration that allows students to observe and manipulate the optical path of polarized light through optically inactive and active solutions. (CCM)

Olfactometric determination of the most potent odor-active compounds in salmon muscle (Salmo salar) smoked by using four smoke generation techniques.

PubMed

Varlet, Vincent; Serot, Thierry; Cardinal, Mireille; Knockaert, Camille; Prost, Carole

2007-05-30

The volatile compounds of salmon fillets smoked according to four smoked generation techniques (smoldering, thermostated plates, friction, and liquid smoke) were investigated. The main odor-active compounds were identified by gas chromatography coupled with olfactometry and mass spectrometry. Only the odorant volatile compounds detected by at least six judges (out of eight) were identified as potent odorants. Phenolic compounds and guaiacol derivatives were the most detected compounds in the olfactometric profile whatever the smoking process and could constitute the smoky odorant skeleton of these products. They were recovered in the aromatic extracts of salmon smoked by smoldering and by friction, which were characterized by 18 and 25 odor-active compounds, respectively. Furannic compounds were more detected in products smoked with thermostated plates characterized by 26 odorants compounds. Finally, the 27 odorants of products treated with liquid smoke were significantly different from the three others techniques applying wood pyrolysis because pyridine derivatives and lipid oxidation products were perceived in the aroma profile.

Identification of ML204, a Novel Potent Antagonist That Selectively Modulates Native TRPC4/C5 Ion Channels*

PubMed Central

Miller, Melissa; Shi, Jie; Zhu, Yingmin; Kustov, Maksym; Tian, Jin-bin; Stevens, Amy; Wu, Meng; Xu, Jia; Long, Shunyou; Yang, Pu; Zholos, Alexander V.; Salovich, James M.; Weaver, C. David; Hopkins, Corey R.; Lindsley, Craig W.; McManus, Owen; Li, Min; Zhu, Michael X.

2011-01-01

Transient receptor potential canonical (TRPC) channels are Ca2+-permeable nonselective cation channels implicated in diverse physiological functions, including smooth muscle contractility and synaptic transmission. However, lack of potent selective pharmacological inhibitors for TRPC channels has limited delineation of the roles of these channels in physiological systems. Here we report the identification and characterization of ML204 as a novel, potent, and selective TRPC4 channel inhibitor. A high throughput fluorescent screen of 305,000 compounds of the Molecular Libraries Small Molecule Repository was performed for inhibitors that blocked intracellular Ca2+ rise in response to stimulation of mouse TRPC4β by μ-opioid receptors. ML204 inhibited TRPC4β-mediated intracellular Ca2+ rise with an IC50 value of 0.96 μm and exhibited 19-fold selectivity against muscarinic receptor-coupled TRPC6 channel activation. In whole-cell patch clamp recordings, ML204 blocked TRPC4β currents activated through either μ-opioid receptor stimulation or intracellular dialysis of guanosine 5′-3-O-(thio)triphosphate (GTPγS), suggesting a direct interaction of ML204 with TRPC4 channels rather than any interference with the signal transduction pathways. Selectivity studies showed no appreciable block by 10–20 μm ML204 of TRPV1, TRPV3, TRPA1, and TRPM8, as well as KCNQ2 and native voltage-gated sodium, potassium, and calcium channels in mouse dorsal root ganglion neurons. In isolated guinea pig ileal myocytes, ML204 blocked muscarinic cation currents activated by bath application of carbachol or intracellular infusion of GTPγS, demonstrating its effectiveness on native TRPC4 currents. Therefore, ML204 represents an excellent novel tool for investigation of TRPC4 channel function and may facilitate the development of therapeutics targeted to TRPC4. PMID:21795696

Dmt and opioid peptides: a potent alliance.

PubMed

Bryant, Sharon D; Jinsmaa, Yunden; Salvadori, Severo; Okada, Yoshio; Lazarus, Lawrence H

2003-01-01

The introduction of the Dmt (2',6'-dimethyl-L-tyrosine)-Tic pharmacophore into the design of opioid ligands produced an extraordinary family of potent delta-opioid receptor antagonists and heralded a new phase in opioid research. First reviewed extensively in 1998, the incorporation of Dmt into a diverse group of opioid molecules stimulated the opioid field leading to the development of unique analogues with remarkable properties. This overview will document the crucial role played by this residue in the proliferation of opioid peptides with high receptor affinity (K(i) equal to or less than 1 nM) and potent bioactivity. The discussion will include the metamorphosis between delta-opioid receptor antagonists to delta-agonists based solely on subtle structural changes at the C-terminal region of the Dmt-Tic pharmacophore as well as their behavior in vivo. Dmt may be considered promiscuous due to the acquisition of potent mu-agonism by dermorphin and endomorphin derivatives as well as by a unique class of opioidmimetics containing two Dmt residues separated by alkyl or pyrazinone linkers. Structural studies on the Dmt-Tic compounds were enhanced tremendously by x-ray diffraction data for three potent and biologically diverse Dmt-Tic opioidmimetics that led to the development of pharmacophores for both delta-opioid receptor agonists and antagonists. Molecular modeling studies of other unique Dmt opioid analogues illuminated structural differences between delta- and mu-receptor ligand interactions. The future of these compounds as therapeutic applications for various medical syndromes including the control of cancer-associated pain is only a matter of time and perseverance. Copyright 2003 Wiley Periodicals, Inc.

A new antifungal protein and a chitinase with prominent macrophage-stimulating activity from seeds of Phaseolus vulgaris cv. pinto.

PubMed

Ye, X Y; Ng, T B

2002-01-18

From the seeds of the pinto bean (Phaseolus vulgaris cv. pinto), a chitinase and a novel antifungal protein, both with the ability of markedly augmenting nitrite production by murine peritoneal macrophages, were isolated. The antifungal proteins, designated phasein A and phasein B, exhibited molecular weights of 28 and 32 kDa, respectively. Phaseins A and B were adsorbed on Affi-gel blue gel and CM-Sepharose and were eluted as adjacent peaks from CM-Sepharose. Phasein A demonstrated potent antifungal activity toward Fusarium oxysporum and Physalospora piricola. Phasein B was more potent than phasein A toward P. piricola but less potent than phasein A toward F. oxysporum and Rhizoctonia solani. Both antifungal proteins inhibited the activity of HIV-1 reverse transcriptase and translation in a rabbit reticulocyte lysate system, with phasein B being more potent. Nitrite production by mouse macrophages was greatly boosted in the presence of both phaseins A and B, although the effect of phasein A was more prominent. The bioactivities of phaseins were in general potent compared with those of other antifungal proteins.

Diethylstilbestrol can effectively accelerate estradiol-17-O-glucuronidation, while potently inhibiting estradiol-3-O-glucuronidation

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

Zhu, Liangliang; Xiao, Ling; Xia, Yangliu

This in vitro study investigates the effects of diethylstilbestrol (DES), a widely used toxic synthetic estrogen, on estradiol-3- and 17-O- (E2-3/17-O) glucuronidation, via culturing human liver microsomes (HLMs) or recombinant UDP-glucuronosyltransferases (UGTs) with DES and E2. DES can potently inhibit E2-3-O-glucuronidation in HLM, a probe reaction for UGT1A1. Kinetic assays indicate that the inhibition follows a competitive inhibition mechanism, with the Ki value of 2.1 ± 0.3 μM, which is less than the possible in vivo level. In contrast to the inhibition on E2-3-O-glucuronidation, the acceleration is observed on E2-17-O-glucuronidation in HLM, in which cholestatic E2-17-O-glucuronide is generated. In themore » presence of DES (0–6.25 μM), K{sub m} values for E2-17-O-glucuronidation are located in the range of 7.2–7.4 μM, while V{sub max} values range from 0.38 to 1.54 nmol/min/mg. The mechanism behind the activation in HLM is further demonstrated by the fact that DES can efficiently elevate the activity of UGT1A4 in catalyzing E2-17-O-glucuronidation. The presence of DES (2 μM) can elevate V{sub max} from 0.016 to 0.81 nmol/min/mg, while lifting K{sub m} in a much lesser extent from 4.4 to 11 μM. Activation of E2-17-O-glucuronidation is well described by a two binding site model, with K{sub A}, α, and β values of 0.077 ± 0.18 μM, 3.3 ± 1.1 and 104 ± 56, respectively. However, diverse effects of DES towards E2-3/17-O-glucuronidation are not observed in liver microsomes from several common experimental animals. In summary, this study issues new potential toxic mechanisms for DES: potently inhibiting the activity of UGT1A1 and powerfully accelerating the formation of cholestatic E2-17-O-glucuronide by UGT1A4. - Highlights: • E2-3-O-glucuronidation in HLM is inhibited when co-incubated with DES. • E2-17-O-glucuronidation in HLM is stimulated when co-incubated with DES. • Acceleration of E2-17-O-glucuronidationin in HLM by DES is via

Newly Identified TLR9 Stimulant, M6-395 Is a Potent Polyclonal Activator for Murine B Cells.

PubMed

Park, Mi-Hee; Jung, Yu-Jin; Kim, Pyeung-Hyeun

2012-02-01

Toll-like receptors (TLRs) have been extensively studied in recent years. However, functions of these molecules in murine B cell biology are largely unknown. A TLR4 stimulant, LPS is well known as a powerful polyclonal activator for murine B cells. In this study, we explored the effect of a murine TLR9 stimulant, M6-395 (a synthetic CpG ODNs) on B cell proliferation and Ig production. First, M6-395 was much more potent than LPS in augmenting B cell proliferation. As for Ig expression, M6-395 facilitated the expression of both TGF-β1-induced germ line transcript α (GLTα) and IL-4-induced GLTγ1 as levels as those by LPS and Pam3CSK4 (TLR1/2 agonist) : a certain Ig GLT expression is regarded as an indicative of the corresponding isotype switching recombination. However, IgA and IgG1 secretion patterns were quite different--these Ig isotype secretions by M6-395 were much less than those by LPS and Pam3CSK4. Moreover, the increase of IgA and IgG1 production by LPS and Pam3CSK4 was virtually abrogated by M6-395. The same was true for the secretion of IgG3. We found that this unexpected phenomena provoked by M6-395 is attributed, at least in part, to its excessive mitogenic nature. Taken together, these results suggest that M6-395 can act as a murine polyclonal activator but its strong mitogenic activity is unfavorable to Ig isotype switching.

H2Oh!: Classroom demonstrations and activities for improving student learning of water concepts

NASA Astrophysics Data System (ADS)

Chan-Hilton, A.; Neupauer, R. M.; Burian, S. J.; Lauer, J. W.; Mathisen, P. P.; Mays, D. C.; Olson, M. S.; Pomeroy, C. A.; Ruddell, B. L.; Sciortino, A.

2012-12-01

Research has shown that the use of demonstrations and hands-on activities in the classroom enhances student learning. Students learn more and enjoy classes more when visual and active learning are incorporated into the lecture. Most college-aged students prefer visual modes of learning, while most instruction is conducted in a lecture, or auditory, format. The use of classroom demonstrations provides opportunities for incorporating visual and active learning into the classroom environment. However, while most instructors acknowledge the benefits of these teaching methods, they typically do not have the time and resources to develop and test such activities and to develop plans to incorporate them into their lectures. Members of the Excellence in Water Resources Education Task Committee of the Environmental and Water Resources Institute (EWRI) of the American Society of Civil Engineers (ASCE) have produced a publication that contains a collection of activities aimed to foster excellence in water resources and hydrology education and improve student learning of principles. The book contains forty-five demonstrations and activities that can be used in water-related classes with topics in fluid mechanics, hydraulics, surface water hydrology, groundwater hydrology, and water quality. We present examples of these activities, including topics such as conservation of momentum, buoyancy, Bernoulli's principle, drag force, pipe flow, watershed delineation, reservoir networks, head distribution in aquifers, and molecular diffusion in a porous medium. Unlike full laboratory exercises, these brief demonstrations and activities (most of which take less than fifteen minutes) can be easily incorporated into classroom lectures. For each demonstration, guidance for preparing and conducting the activity, along with a brief overview of the principles that are demonstrated, is provided. The target audience of the activities is undergraduate students, although the activities also may be

Synthesis and biological activity of N-arylpiperazine-modified analogues of KN-62, a potent antagonist of the purinergic P2X7 receptor.

PubMed

Baraldi, Pier Giovanni; del Carmen Nuñez, Maria; Morelli, Anna; Falzoni, Simonetta; Di Virgilio, Francesco; Romagnoli, Romeo

2003-04-10

The P2X(7) receptor is involved in several processes relevant to inflammation (cytokine release, NO generation, killing of intracellular pathogens, cytotoxicity); thus, it may be an appealing target for pharmacological intervention. The characterization of native and recombinant P2X(7) receptor continues to be hindered by the lack of specific and subtype-selective antagonists. However, a tyrosine derivative named KN-62 exhibits selective P2X(7) receptor-blocking properties. The present study was designed to evaluate the functional antagonistic properties of a novel series of KN-62-related compounds characterized by the presence of different phenyl-substituted piperazine moieties. Antagonistic activity of KN-62 derivatives was tested on HEK293 cells transduced with the human P2X(7) receptor and monocyte-derived human macrophages, a cell type well-known for the high level of expression of this receptor. The biological responses investigated were ATP-dependent Ca(2+) influx across the plasma membrane, ethidium bromide uptake, and secretion of the cytokine interleukin-1beta. KN-62 was characterized by the presence of a phenylpiperazine moiety, and the presence of a one-carbon linker between the piperazine nitrogen and the phenyl ring (compound 61) increases the activity, while a two-carbon linker (compound 62) decreases biological activity 10-fold. Also, the nature and the position of substituents on the phenyl ring tethered to the piperazine seemed to exert a fundamental influence on the biological activity. In the series of synthesized compounds, the presence of a fluorine in the para position gives the most potent compound (63), while the same atom in the ortho position reduces potency by 3-fold. When the p-fluorine was replaced in the same position with other halogens, such as chlorine (compound 64) or iodine (compound 65), the activity decreased dramatically. We then tested the activity of the four most potent KN-62 derivatives on ATP-stimulated secretion of IL-1

Alcoholic Fractions F5 and F6 from Withania somnifera Leaves Show a Potent Antileishmanial and Immunomodulatory Activities to Control Experimental Visceral Leishmaniasis

PubMed Central

Chandrasekaran, Sambamurthy; Veronica, Jalaja; Sundar, Shyam; Maurya, Radheshyam

2017-01-01

Visceral leishmaniasis (VL) causes fatal life-threatening disease, if left untreated. The current drugs have various limitations; hence, natural products from medicinal plants are being focused in search of new drugs to treat leishmaniasis. The aim of the present study was to evaluate the antileishmanial and immunomodulatory activities of F5 and F6 alcoholic fractions from Withania somnifera leaves and purified withaferin-A in Leishmania donovani-infected peritoneal macrophages and BALB/c mice. We observed that F5 (15 µg/mL), F6 (10 µg/mL), and withaferin-A (1.5 µM) reduce amastigote count in peritoneal macrophages and induce reactive oxygen species and significant decrease in IL-10 mRNA expression compared to control upon treatment. Subsequently, in vivo study mice were treated with F5 (25 and 50 mg/kg b.wt.), F6 (25 and 50 mg/kg b.wt.) orally, and withaferin-A (2 mg/kg b.wt.) intraperitoneally for 10 consecutive days and a drastic reduction in parasite burden in both spleen and liver were observed. The treatment resulted in the reduction in IL-10, IL-4, and TGF-β mRNA expression and a significant increase in IFN-γ/IL-10 expression ratio in the treated group compared to control. The humoral response of these alcoholic fractions and withaferin-A shows increased IgG2a levels when compared with IgG1 in treated mice. Taken together, our result concludes that withanolides in alcoholic fractions demonstrate a potent antileishmanial and immunomodulatory activities in experimental VL. PMID:28553635

Anti-AIDS agents 81. Design, synthesis, and structure-activity relationship study of betulinic acid and moronic acid derivatives as potent HIV maturation inhibitors.

PubMed

Qian, Keduo; Kuo, Reen-Yun; Chen, Chin-Ho; Huang, Li; Morris-Natschke, Susan L; Lee, Kuo-Hsiung

2010-04-22

In our continuing study of triterpene derivatives as potent anti-HIV agents, different C-3 conformationally restricted betulinic acid (BA, 1) derivatives were designed and synthesized in order to explore the conformational space of the C-3 pharmacophore. 3-O-Monomethylsuccinyl-betulinic acid (MSB) analogues were also designed to better understand the contribution of the C-3' dimethyl group of bevirimat (2), the first-in-class HIV maturation inhibitor, which is currently in phase IIb clinical trials. In addition, another triterpene skeleton, moronic acid (MA, 3), was also employed to study the influence of the backbone and the C-3 modification toward the anti-HIV activity of this compound class. This study enabled us to better understand the structure-activity relationships (SAR) of triterpene-derived anti-HIV agents and led to the design and synthesis of compound 12 (EC(50): 0.0006 microM), which displayed slightly better activity than 2 as a HIV-1 maturation inhibitor.

Oxadiazole-isopropylamides as Potent and Non-covalent Proteasome Inhibitors

PubMed Central

Ozcan, Sevil; Kazi, Aslamuzzaman; Marsilio, Frank; Fang, Bin; Guida, Wayne C.; Koomen, John; Lawrence, Harshani R.; Sebti, Saïd M.

2013-01-01

Screening of the 50,000 ChemBridge compound library led to the identification of the oxadiazole-isopropylamide 1 (PI-1833) which inhibited CT-L activity (IC50 0.60 μM) with little effects on the other 2 major proteasome proteolytic activities, T-L and PGPH-L. LC/MS-MS and dialysis show that 1 is a non-covalent and rapidly reversible CT-L inhibitor. Focused library synthesis provided 11ad (PI-1840) with CT-L activity (IC50 27 nM). Detailed SAR studies indicate that the amide moiety and the 2 phenyl rings are sensitive toward modifications. Hydrophobic residues, such as propyl or butyl, in the para-position (not ortho or meta) of the A-ring and a meta-pyridyl group as B-ring significantly improve activity. Compound 11ad (IC50 0.37 μM) is more potent than 1 (IC50 3.5 μM) at inhibiting CT-L activity in intact MDA-MB-468 human breast cancer cells and inhibiting their survival. The activity of 11ad warrants further pre-clinical investigation of this class as non-covalent proteasome inhibitors. PMID:23547706

VX-509 (decernotinib) is a potent and selective janus kinase 3 inhibitor that attenuates inflammation in animal models of autoimmune disease.

PubMed

Mahajan, Sudipta; Hogan, James K; Shlyakhter, Dina; Oh, Luke; Salituro, Francesco G; Farmer, Luc; Hoock, Thomas C

2015-05-01

Cytokines, growth factors, and other chemical messengers rely on a class of intracellular nonreceptor tyrosine kinases known as Janus kinases (JAKs) to rapidly transduce intracellular signals. A number of these cytokines are critical for lymphocyte development and mediating immune responses. JAK3 is of particular interest due to its importance in immune function and its expression, which is largely confined to lymphocytes, thus limiting the potential impact of JAK3 inhibition on nonimmune physiology. The aim of this study was to evaluate the potency and selectivity of the investigational JAK3 inhibitor VX-509 (decernotinib) [(R)-2-((2-(1H-pyrrolo[2,3-b]pyridin-3-yl)pyrimidin-4-yl)amino)-2-methyl-N-(2,2,2-trifluoroethyl)butanamide] against JAK3 kinase activity and inhibition of JAK3-mediated signaling in vitro and JAK3-dependent physiologic processes in vivo. These results demonstrate that VX-509 potently inhibits JAK3 in enzyme assays (Ki = 2.5 nM + 0.7 nM) and cellular assays dependent on JAK3 activity (IC50 range, 50-170 nM), with limited or no measurable potency against other JAK isotypes or non-JAK kinases. VX-509 also showed activity in two animal models of aberrant immune function. VX-509 treatment resulted in dose-dependent reduction in ankle swelling and paw weight and improved paw histopathology scores in the rat collagen-induced arthritis model. In a mouse model of oxazolone-induced delayed-type hypersensitivity, VX-509 reduced the T cell-mediated inflammatory response in skin. These findings demonstrate that VX-509 is a selective and potent inhibitor of JAK3 in vitro and modulates proinflammatory response in models of immune-mediated diseases, such as collagen-induced arthritis and delayed-type hypersensitivity. The data support evaluation of VX-509 for treatment of patients with autoimmune and inflammatory diseases such as rheumatoid arthritis. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Rational Design and Synthesis of Biologically Active Disubstituted 2(3H) Furanones and Pyrrolone Derivatives as Potent and Safer Non Steroidal Anti-inflammatory Agents.

PubMed

Khokra, S L; Khan, S A; Choudhary, D; Hasan, S M; Ahmad, A; Husain, Asif

2016-01-01

Furanone and pyrrolone heterocyclic ring system represent important and interesting classes of bioactive compounds. Medicinal chemists use these heterocycyclic moieties as scaffolds in drug design and discovery. A series of 3-arylidene-5-(naphthalene-2-yl)-furan-2(3H)-ones (2a-j) were synthesized by incorporating pharmacophore of COX-2 inhibitor rofecoxib and naphthyl ring of naproxen as potential non steroidal anti-inflammatory agents. These furanone derivatives were subsequently reacted with dry ammonia gas and benzylamine to furnish corresponding 3-arylidene-5-(naphthlen-2-yl)-1H-pyrrol-2(3H)-ones (3a-e) and 3-arylidene-1-benzyl-5- (naphthalene-2-yl)-1H-pyrrol-2(3H)-ones (4a-e), respectively. The newly prepared heterocyclics were screened for their expected in-vivo biological activities including anti-inflammatory, analgesic and ulcerogenic actions in rodents. The COX-2 inhibitory behavior of synthesized compounds was also assessed via automated docking studies. The chemical structure of the synthesized compounds was characterized by using modern spectroscopic techniques. Result of in-vivo pharmacological studies demonstrated that almost all N-Benzyl-pyrrol-2(3H)-ones (4a-e) showed better anti-inflammatory and analgesic activities in comparison with the other two series of furan-2(3H)-ones and pyrrol- 2(3H)-ones. The moldock score value of the tested compounds was found in the range of -116.66 to -170.328 and was better than the standard drug. Among all the synthesized compounds, only nine compounds (2d, 2g, 2h, 3d, 4a, 4b, 4c, 4d and 4e) exhibited potent anti-inflammatory and analgesic activities with significantly reduced gastrointestinal toxicity in various animal models in comparison to standard drug, diclofenac. Therefore, it is recommended to explore the potential of the synthesized compounds as lead candidates for the development of new therapeutic agents.

Potent virucidal effect of pheophorbide a and pyropheophorbide a on enveloped viruses.

PubMed

Bouslama, Lamjed; Hayashi, Kyoko; Lee, Jung-Bum; Ghorbel, Abdelwahed; Hayashi, Toshimitsu

2011-01-01

In this study, we evaluated the inhibitory effect of ethanol and aqueous extracts from a stem of Opuntia ficus indica on replication of three kinds of viruses: two enveloped viruses [herpes simplex virus type 2 (HSV-2), influenza A virus (IFV-A)], and one non-enveloped virus [poliovirus type 1 (PV-1)]. Only ethanol extract from the cactus stem showed significant antiviral activity in vitro. Two chlorophyll derivatives, pheophorbide a and pyropheophorbide a, were isolated as active substances exhibiting potent virucidal effects on HSV-2 and IFV-A, but no activity against PV-1 was observed. These findings suggest that these active compounds might recognize specific glycoproteins of enveloped viruses, precluding their binding to host cell receptors and inhibiting viral infections.

Characterisation of CCT271850, a selective, oral and potent MPS1 inhibitor, used to directly measure in vivo MPS1 inhibition vs therapeutic efficacy

PubMed Central

Faisal, Amir; Mak, Grace W Y; Gurden, Mark D; Xavier, Cristina P R; Anderhub, Simon J; Innocenti, Paolo; Westwood, Isaac M; Naud, Sébastien; Hayes, Angela; Box, Gary; Valenti, Melanie R; De Haven Brandon, Alexis K; O'Fee, Lisa; Schmitt, Jessica; Woodward, Hannah L; Burke, Rosemary; vanMontfort, Rob L M; Blagg, Julian; Raynaud, Florence I; Eccles, Suzanne A; Hoelder, Swen; Linardopoulos, Spiros

2017-01-01

Background: The main role of the cell cycle is to enable error-free DNA replication, chromosome segregation and cytokinesis. One of the best characterised checkpoint pathways is the spindle assembly checkpoint, which prevents anaphase onset until the appropriate attachment and tension across kinetochores is achieved. MPS1 kinase activity is essential for the activation of the spindle assembly checkpoint and has been shown to be deregulated in human tumours with chromosomal instability and aneuploidy. Therefore, MPS1 inhibition represents an attractive strategy to target cancers. Methods: To evaluate CCT271850 cellular potency, two specific antibodies that recognise the activation sites of MPS1 were used and its antiproliferative activity was determined in 91 human cancer cell lines. DLD1 cells with induced GFP-MPS1 and HCT116 cells were used in in vivo studies to directly measure MPS1 inhibition and efficacy of CCT271850 treatment. Results: CCT271850 selectively and potently inhibits MPS1 kinase activity in biochemical and cellular assays and in in vivo models. Mechanistically, tumour cells treated with CCT271850 acquire aberrant numbers of chromosomes and the majority of cells divide their chromosomes without proper alignment because of abrogation of the mitotic checkpoint, leading to cell death. We demonstrated a moderate level of efficacy of CCT271850 as a single agent in a human colorectal carcinoma xenograft model. Conclusions: CCT271850 is a potent, selective and orally bioavailable MPS1 kinase inhibitor. On the basis of in vivo pharmacodynamic vs efficacy relationships, we predict that more than 80% inhibition of MPS1 activity for at least 24 h is required to achieve tumour stasis or regression by CCT271850. PMID:28334731

Characterisation of CCT271850, a selective, oral and potent MPS1 inhibitor, used to directly measure in vivo MPS1 inhibition vs therapeutic efficacy.

PubMed

Faisal, Amir; Mak, Grace W Y; Gurden, Mark D; Xavier, Cristina P R; Anderhub, Simon J; Innocenti, Paolo; Westwood, Isaac M; Naud, Sébastien; Hayes, Angela; Box, Gary; Valenti, Melanie R; De Haven Brandon, Alexis K; O'Fee, Lisa; Schmitt, Jessica; Woodward, Hannah L; Burke, Rosemary; vanMontfort, Rob L M; Blagg, Julian; Raynaud, Florence I; Eccles, Suzanne A; Hoelder, Swen; Linardopoulos, Spiros

2017-04-25

The main role of the cell cycle is to enable error-free DNA replication, chromosome segregation and cytokinesis. One of the best characterised checkpoint pathways is the spindle assembly checkpoint, which prevents anaphase onset until the appropriate attachment and tension across kinetochores is achieved. MPS1 kinase activity is essential for the activation of the spindle assembly checkpoint and has been shown to be deregulated in human tumours with chromosomal instability and aneuploidy. Therefore, MPS1 inhibition represents an attractive strategy to target cancers. To evaluate CCT271850 cellular potency, two specific antibodies that recognise the activation sites of MPS1 were used and its antiproliferative activity was determined in 91 human cancer cell lines. DLD1 cells with induced GFP-MPS1 and HCT116 cells were used in in vivo studies to directly measure MPS1 inhibition and efficacy of CCT271850 treatment. CCT271850 selectively and potently inhibits MPS1 kinase activity in biochemical and cellular assays and in in vivo models. Mechanistically, tumour cells treated with CCT271850 acquire aberrant numbers of chromosomes and the majority of cells divide their chromosomes without proper alignment because of abrogation of the mitotic checkpoint, leading to cell death. We demonstrated a moderate level of efficacy of CCT271850 as a single agent in a human colorectal carcinoma xenograft model. CCT271850 is a potent, selective and orally bioavailable MPS1 kinase inhibitor. On the basis of in vivo pharmacodynamic vs efficacy relationships, we predict that more than 80% inhibition of MPS1 activity for at least 24 h is required to achieve tumour stasis or regression by CCT271850.

2,4-Dihydroxychalcone derivatives as novel potent cell division cycle 25B phosphatase inhibitors and protein tyrosine phosphatase 1B inhibitors.

PubMed

Xie, Chao; Sun, Yuan; Pan, Cheng-Yan; Tang, Li-Ming; Guan, Li-Ping

2014-04-01

Eleven 2,4-dihydroxychalcone compounds were synthesized and identified as reversible and competitive cell division cycle 25 (CDC25) B and protein tyrosine phosphatase (PTP) 1B inhibitors with inhibition values in the micromolar range. The results showed that nine compounds significantly inhibited CDC25B phosphatase, whereas seven compounds inhibited the activity against PTP1B in vitro. Compound 8 had the greatest inhibition activity against CDC25B and PTP1B in vitro, with percentage inhibition values of 97.5% and 96.3% at a dose of 20 microg/mL, respectively. Cytotoxic activity assays revealed that compound 8 was the most potent against HCT116, HeLa, and A549 cells. Furthermore, compound 8 exhibited potent antitumor activity in a colo205 xenograft model.

2-(4-aminophenyl) benzothiazole: a potent and selective pharmacophore with novel mechanistic action towards various tumour cell lines.

PubMed

Dubey, Raghvendra; Shrivastava, Prabhat K; Basniwal, Pawan K; Bhattacharya, Snehendu; Moorthy, Narayana S Hari Narayana

2006-06-01

2-(4-aminophenyl) benzothiazole (CJM -126) (Table 1 (1) and its analogues represent a potent and highly selective class of antitumor agents. These compounds in nanomolar range elicit potent growth inhibition in human-derived breast, colon, ovarian and renal tumour cell lines. Metabolism of benzothiazole plays a central role in its mode of action. Cytocrome P450 isoform, CYP1A1, biotransforms benzothiazoles, to active, as well as inactive metabolites. In vitro studies had confirmed that N-oxidation and N-acetylation (only 3' halogen congener) as main active metabolic transformation (generating cytotoxic electrophilic species), while C-6 oxidation and N-acetylation (except 3' halogen congener) as inactive metabolic transformation pathway. Generation of an inactive metabolite 2-(4-aminophenyl)-6-hydoxybenzothiazole [6-OH 126, (Table 1) (10)] is blocked by fluorinated analogue, substituted around benzothiazole nucleus, especially at 5-position. National Cancer Institute (NCI), USA, confirms this series as a unique mechanistic class distinct from clinically used chemotherapeutic agents. Benzothiazoles are potent aryl hydrocarbon receptor (AhR) agonists, binding to AhR results in induction of CYP1A1, causes generation of electrophilic reactive species which forms DNA adduct, ultimately resulting in cell death by activation of apoptotic machinery. To overcome the poor physiochemical and pharmaceutical properties (bioavailability problem) of this compounds, prodrug of benzothiazole derivatives were synthesized, which are introduced in clinical trails.

Discovery of Potent and Selective Dipeptidyl Peptidase IV Inhibitors Derived from [beta]-Aminoamides Bearing Subsituted Triazolopiperazines

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

Kim, Dooseop; Kowalchick, Jennifer E.; Brockunier, Linda L.

2008-06-30

A series of {beta}-aminoamides bearing triazolopiperazines have been discovered as potent, selective, and orally active dipeptidyl peptidase IV (DPP-4) inhibitors by extensive structure-activity relationship (SAR) studies around the triazolopiperazine moiety. Among these, compound 34b with excellent in vitro potency (IC{sub 50} = 4.3 nM) against DPP-4, high selectivity over other enzymes, and good pharmacokinetic profiles exhibited pronounced in vivo efficacy in an oral glucose tolerance test (OGTT) in lean mice. On the basis of these properties, compound 34b has been profiled in detail. Further refinement of the triazolopiperazines resulted in the discovery of a series of extremely potent compounds withmore » subnanomolar activity against DPP-4 (42b-49b), that is, 4-fluorobenzyl-substituted compound 46b, which is notable for its superior potency (IC{sub 50} = 0.18 nM). X-ray crystal structure determination of compounds 34b and 46b in complex with DPP-4 enzyme revealed that (R)-stereochemistry at the 8-position of triazolopiperazines is strongly preferred over (S) with respect to DPP-4 inhibition.« less

Potent and Selective Phosphopeptide Mimetic Prodrugs Targeted to the Src Homology 2 (SH2) Domain of Signal Transducer and Activator of Transcription 3

PubMed Central

Mandal, Pijus K.; Gao, Fengqin; Lu, Zhen; Ren, Zhiyong; Ramesh, Rajagopal; Birtwistle, J. Sanderson; Kaluarachchi, Kumaralal K.; Chen, Xiaomin; Bast, Robert C.; Liao, Warren S.; McMurray, John S.

2011-01-01

Signal transducer and activator of transcription 3 (Stat3), a target for anticancer drug design, is activated by recruitment to phosphotyrosine residues on growth factor and cytokine receptors via its SH2 domain. We report here structure-activity relationship studies on phosphopeptide mimics targeted to the SH2 domain of Stat3. Inclusion of a methyl group on the β-position of the pTyr mimic, 4-phosphocinfnamide, enhanced affinity 2–3 fold. Bis-pivaloyloxymethyl prodrugs containing β-methyl cinnamide, dipeptide scaffolds Haic and Nle-cis-3,4-methanoproline, and glutamine surrogates were highly potent, completely inhibiting phosphorylation of Stat3 Tyr705 at 0.5–1 µM in a variety of cancer cell lines. The inhibitors were selective for Stat3 over Stat1, Stat5, Src, and p85 of PI3K, indicating ability to discriminate individual SH2 domains in intact cells. At concentrations that completely inhibited Stat3 phosphorylation, the prodrugs were not cytotoxic to a panel of tumor cells, thereby showing clear distinction between cytotoxicity and effects downstream of activated Stat3. PMID:21486047

[Ecological demonstration activity and eco-civilization construction mode: review and prospects].

PubMed

Mao, Hui-ping; He, Xuan; He, Jia; Niu, Dong-jie; Bao, Cun-kuan

2013-04-01

Ecological civilization is to normalize human development behaviors to harmonize the relationships between social and ecological development and eco-environment protection. In this paper, a comparative analysis was made on the ecological demonstration activities of ecological demonstration areas led by the Ministry of Environmental Protection, exemplar cities of national environmental protection, and ecological provinces, cities, and counties. It was considered that all the ecological demonstration activities had the problems of lacking pertinence of construction goals, disordered construction subjects, inefficient construction processes, and lacking continuous incentive mechanisms of assessment. In the meantime, through the analysis of the connotations of eco-civilization, the relationships between eco-civilization and eco-demonstration constructions were approached, and the eco-civilization construction mode was put forward in terms of construction goal, construction subject, and construction processes and assessment. The construction mode included the construction goal based on regional characteristics; the synergistic cooperation of construction subjects, the expanding ways of public participation, and the establishment of evaluation system for comprehensively measuring the 'actions and results'.

Potent inhibition of cytochrome P450 2B6 by sibutramine in human liver microsomes.

PubMed

Bae, Soo Hyeon; Kwon, Min Jo; Choi, Eu Jin; Zheng, Yu Fen; Yoon, Kee Dong; Liu, Kwang-Hyeon; Bae, Soo Kyung

2013-09-05

The present study was performed to evaluate the potency and specificity of sibutramine as an inhibitor of the activities of nine human CYP isoforms in liver microsomes. Using a cocktail assay, the effects of sibutramine on specific marker reactions of the nine CYP isoforms were measured in human liver microsomes. Sibutramine showed potent inhibition of CYP2B6-mediated bupropion 6-hydroxylation with an IC50 value of 1.61μM and Ki value of 0.466μM in a competitive manner at microsomal protein concentrations of 0.25mg/ml; this was 3.49-fold more potent than the typical CYP2B6 inhibitor thio-TEPA (Ki=1.59μM). In addition, sibutramine slightly inhibited CYP2C19 activity (Ki=16.6μM, noncompetitive inhibition) and CYP2D6 activity (Ki=15.7μM, noncompetitive inhibition). These observations indicated 35.6- and 33.7-fold decreases in inhibition potency, respectively, compared with that of CYP2B6 by sibutramine. However, no inhibition of CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6, or CYP2E1 activities was observed. In addition, the CYP2B6 inhibitory potential of sibutramine was enhanced at a lower microsomal protein concentration of 0.05mg/ml. After 30min preincubation of human liver microsomes with sibutramine in the presence of NADPH, no shift in IC50 was observed in terms of inhibition of the activities of the nine CYPs, suggesting that sibutramine is not a time-dependent inactivator. These observations suggest that sibutramine is a selective and potent inhibitor of CYP2B6 in vitro, whereas inhibition of other CYPs is substantially lower. These in vitro data support the use of sibutramine as a well-known inhibitor of CYP2B6 for routine screening of P450 reversible inhibition when human liver microsomes are used as the enzyme source. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.