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 chiral dihydropyridopyrimidinones as potent, selective and orally bioavailable inhibitors of AKT.

PubMed

Parthasarathy, Saravanan; Henry, Kenneth; Pei, Huaxing; Clayton, Josh; Rempala, Mark; Johns, Deidre; De Frutos, Oscar; Garcia, Pablo; Mateos, Carlos; Pleite, Sehila; Wang, Yong; Stout, Stephanie; Condon, Bradley; Ashok, Sheela; Lu, Zhohai; Ehlhardt, William; Raub, Tom; Lai, Mei; Geeganage, Sandaruwan; Burkholder, Timothy P

2018-06-01

During the course of our research efforts to develop potent and selective AKT inhibitors, we discovered enatiomerically pure substituted dihydropyridopyrimidinones (DHP) as potent inhibitors of protein kinase B/AKT with excellent selectivity against ROCK 2 . A key challenge in this program was the poor physicochemical properties of the initial lead compound 5. Integration of structure-based drug design and physical properties-based design resulted in replacement of a highly hydrophobic poly fluorinated aryl ring by a simple trifluoromethyl that led to identification of compound 6 with much improved physicochemical properties. Subsequent SAR studies led to the synthesis of new pyran analog 7 with improved cell potency. Further optimization of pharmacokintetics properties by increasing permeability with appropriate fluorinated alkyl led to compound 8 as a potent, selective AKT inhibitors that blocks the phosphorylation of GSK3β in vivo and had robust, dose and concentration dependent efficacy in the U87MG tumor xenograft model. Copyright © 2018 Elsevier Ltd. All rights reserved.

High-Throughput Screening To Identify Potent and Specific Inhibitors of Microbial Sulfate Reduction.

PubMed

Carlson, Hans K; Mullan, Mark R; Mosqueda, Lorraine A; Chen, Steven; Arkin, Michelle R; Coates, John D

2017-06-20

The selective perturbation of complex microbial ecosystems to predictably influence outcomes in engineered and industrial environments remains a grand challenge for geomicrobiology. In some industrial ecosystems, such as oil reservoirs, sulfate reducing microorganisms (SRM) produce hydrogen sulfide which is toxic, explosive, and corrosive. Despite the economic cost of sulfidogenesis, there has been minimal exploration of the chemical space of possible inhibitory compounds, and very little work has quantitatively assessed the selectivity of putative souring treatments. We have developed a high-throughput screening strategy to identify potent and selective inhibitors of SRM, quantitatively ranked the selectivity and potency of hundreds of compounds and identified previously unrecognized SRM selective inhibitors and synergistic interactions between inhibitors. Zinc pyrithione is the most potent inhibitor of sulfidogenesis that we identified, and is several orders of magnitude more potent than commonly used industrial biocides. Both zinc and copper pyrithione are also moderately selective against SRM. The high-throughput (HT) approach we present can be readily adapted to target SRM in diverse environments and similar strategies could be used to quantify the potency and selectivity of inhibitors of a variety of microbial metabolisms. Our findings and approach are relevant to efforts to engineer environmental ecosystems and also to understand the role of natural gradients in shaping microbial niche space.

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.

Draft Genome Sequence of the Polyextremophilic Halorubrum sp. Strain AJ67, Isolated from Hyperarsenic Lakes in the Argentinian Puna

PubMed Central

Burguener, Germán F.; Maldonado, Marcos J.; Revale, Santiago; Fernández Do Porto, Darío; Rascován, Nicolás; Vázquez, Martín; Farías, María Eugenia; Marti, Marcelo A.

2014-01-01

Halorubrum sp. strain AJ67, an extreme halophilic UV-resistant archaeon, was isolated from Laguna Antofalla in the Argentinian Puna. The draft genome sequence suggests the presence of potent enzyme candidates that are essential for survival under multiple environmental extreme conditions, such as high UV radiation, elevated salinity, and the presence of critical arsenic concentrations. PMID:24503991

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.

Antiproliferative activity of king cobra (Ophiophagus hannah) venom L-amino acid oxidase.

PubMed

Li Lee, Mui; Chung, Ivy; Yee Fung, Shin; Kanthimathi, M S; Hong Tan, Nget

2014-04-01

King cobra (Ophiophagus hannah) venom L-amino acid oxidase (LAAO), a heat-stable enzyme, is an extremely potent antiproliferative agent against cancer cells when compared with LAAO isolated from other snake venoms. King cobra venom LAAO was shown to exhibit very strong antiproliferative activities against MCF-7 (human breast adenocarcinoma) and A549 (human lung adenocarcinoma) cells, with an IC50 value of 0.04±0.00 and 0.05±0.00 μg/mL, respectively, after 72-hr treatment. In comparison, its cytotoxicity was about 3-4 times lower when tested against human non-tumourigenic breast (184B5) and lung (NL 20) cells, suggesting selective antitumour activity. Furthermore, its potency in MCF-7 and A549 cell lines was greater than the effects of doxorubicin, a clinically established cancer chemotherapeutic agent, which showed an IC50 value of 0.18±0.03 and 0.63±0.21 μg/mL, respectively, against the two cell lines. The selective cytotoxic action of the LAAO was confirmed by phycoerythrin (PE) annexin V/7-amino-actinomycin (AAD) apoptotic assay, in which a significant increase in apoptotic cells was observed in LAAO-treated tumour cells than in their non-tumourigenic counterparts. The ability of LAAO to induce apoptosis in tumour cells was further demonstrated using caspase-3/7 and DNA fragmentation assays. We also determined that this enzyme may target oxidative stress in its killing of tumour cells, as its cytotoxicity was significantly reduced in the presence of catalase (a H2O2 scavenger). In view of its heat stability and selective and potent cytotoxic action on cancer cells, king cobra venom LAAO can be potentially developed for treating solid tumours. © 2013 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

A-C Estrogens as Potent and Selective Estrogen Receptor-Beta Agonists (SERBAs) to Enhance Memory Consolidation under Low-Estrogen Conditions.

PubMed

Hanson, Alicia M; Perera, K L Iresha Sampathi; Kim, Jaekyoon; Pandey, Rajesh K; Sweeney, Noreena; Lu, Xingyun; Imhoff, Andrea; Mackinnon, Alexander Craig; Wargolet, Adam J; Van Hart, Rochelle M; Frick, Karyn M; Donaldson, William A; Sem, Daniel S

2018-06-14

Estrogen receptor-beta (ERβ) is a drug target for memory consolidation in postmenopausal women. Herein is reported a series of potent and selective ERβ agonists (SERBAs) with in vivo efficacy that are A-C estrogens, lacking the B and D estrogen rings. The most potent and selective A-C estrogen is selective for activating ER relative to seven other nuclear hormone receptors, with a surprising 750-fold selectivity for the β over α isoform and with EC 50 s of 20-30 nM in cell-based and direct binding assays. Comparison of potency in different assays suggests that the ER isoform selectivity is related to the compound's ability to drive the productive conformational change needed to activate transcription. The compound also shows in vivo efficacy after microinfusion into the dorsal hippocampus and after intraperitoneal injection (0.5 mg/kg) or oral gavage (0.5 mg/kg). This simple yet novel A-C estrogen is selective, brain penetrant, and facilitates memory consolidation.

Verification of surface preparation for adhesive bonding

NASA Technical Reports Server (NTRS)

Myers, Rodney S.

1995-01-01

A survey of solid rocket booster (SRB) production operations identified potential contaminants which might adversely affect bonding operations. Lap shear tests quantified these contaminants' effects on adhesive strength. The most potent contaminants were selected for additional studies on SRB thermal protection system (TPS) bonding processes. Test panels were prepared with predetermined levels of contamination, visually inspected using white and black light, then bonded with three different TPS materials over the unremoved contamination. Bond test data showed that white and black light inspections are adequate inspection methods for TPS bonding operations. Extreme levels of contamination (higher than expected on flight hardware) had an insignificant effect on TPS bond strengths because of the apparent insensitivity of the adhesive system to contamination effects, and the comparatively weak cohesive strength of the TPS materials.

Tranylcypromine Substituted cis-Hydroxycyclobutylnaphthamides as Potent and Selective Dopamine D3 Receptor Antagonists

PubMed Central

2015-01-01

We report a class of potent and selective dopamine D3 receptor antagonists based upon tranylcypromine. Although tranylcypromine has a low affinity for the rat D3 receptor (Ki = 12.8 μM), our efforts have yielded (1R,2S)-11 (CJ-1882), which has Ki values of 2.7 and 2.8 nM at the rat and human dopamine D3 receptors, respectively, and displays respective selectivities of >10000-fold and 223-fold over the rat and human D2 receptors. Evaluation in a β-arrestin functional assay showed that (1R,2S)-11 is a potent and competitive antagonist at the human D3 receptor. PMID:24848155

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

PubMed Central

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

2010-01-01

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

Lactimidomycin, Iso-migrastatin and Related Glutarimide-containing 12-membered Macrolides are Extremely Potent Inhibitors of Cell Migration

PubMed Central

Ju, Jianhua; Rajski, Scott R.; Lim, Si-Kyu; Seo, Jeong-Woo; Peters, Noël R.; Hoffmann, F. Michael; Shen, Ben

2009-01-01

Migrastatin (1), iso-migrastatin (5) and lactimidomycin (7) are all glutarimide-containing polyketides known for their unique structures and cytotoxic activities against human cancer cell lines. Migrastatin, a strong inhibitor of tumor cell migration, has been an important lead in the development of antimetastatic agents. Yet studies of the related 12-membered macrolides iso-migrastatin, lactimidomycin and related analogs have been hampered by their limited availability. We report here the production, isolation, structural characterization and biological activities of iso-migrastatin, lactimidomycin, and 23 related congeners. Our studies showed that, as a family, the glutarimide-containing 12-membered macrolides are extremely potent cell migration inhibitors with some members displaying activity on par or superior to that of migrastatin as exemplified by compounds 5, 7, and 9–12. On the basis of these findings, the structures and activity of this family of compounds as cell migration inhibitors are discussed. PMID:19132897

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.

AVN-492, A Novel Highly Selective 5-HT6R Antagonist: Preclinical Evaluation.

PubMed

Ivachtchenko, Alexandre V; Okun, Ilya; Aladinskiy, Vladimir; Ivanenkov, Yan; Koryakova, Angela; Karapetyan, Ruben; Mitkin, Oleg; Salimov, Ramiz; Ivashchenko, Andrey

2017-01-01

Discovery of 5-HT6 receptor subtype and its exclusive localization within the central nervous system led to extensive investigations of its role in Alzheimer's disease, schizophrenia, and obesity. In the present study, we present preclinical evaluation of a novel highly-potent and highly-selective 5-HT6R antagonist, AVN-492. The affinity of AVN-492 to bind to 5-HT6R (Ki = 91 pM) was more than three orders of magnitude higher than that to bind to the only other target, 5-HT2BR, (Ki = 170 nM). Thus, the compound displayed great 5-HT6R selectivity against all other serotonin receptor subtypes, and is extremely specific against any other receptors such as adrenergic, GABAergic, dopaminergic, histaminergic, etc. AVN-492 demonstrates good in vitro and in vivo ADME profile with high oral bioavailability and good brain permeability in rodents. In behavioral tests, AVN-492 shows anxiolytic effect in elevated plus-maze model, prevents an apomorphine-induced disruption of startle pre-pulse inhibition (the PPI model) and reverses a scopolamine- and MK-801-induced memory deficit in passive avoidance model. No anti-obesity effect of AVN-492 was found in a murine model. The data presented here strongly indicate that due to its high oral bioavailability, extremely high selectivity, and potency to block the 5-HT6 receptor, AVN-492 is a very promising tool for evaluating the role the 5-HT6 receptor might play in cognitive and neurodegenerative impairments. AVN-492 is an excellent drug candidate to be tested for treatment of such diseases, and is currently being tested in Phase I trials.

Towards New Antifolates Targeting Eukaryotic Opportunistic Infections

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

Liu, J.; Bolstad, D; Bolstad, E

2009-01-01

Trimethoprim, an antifolate commonly prescribed in combination with sulfamethoxazole, potently inhibits several prokaryotic species of dihydrofolate reductase (DHFR). However, several eukaryotic pathogenic organisms are resistant to trimethoprim, preventing its effective use as a therapeutic for those infections. We have been building a program to reengineer trimethoprim to more potently and selectively inhibit eukaryotic species of DHFR as a viable strategy for new drug discovery targeting several opportunistic pathogens. We have developed a series of compounds that exhibit potent and selective inhibition of DHFR from the parasitic protozoa Cryptosporidium and Toxoplasma as well as the fungus Candida glabrata. A comparison ofmore » the structures of DHFR from the fungal species Candida glabrata and Pneumocystis suggests that the compounds may also potently inhibit Pneumocystis DHFR.« less

Identification of highly selective and potent histone deacetylase 3 inhibitors using click chemistry-based combinatorial fragment assembly.

PubMed

Suzuki, Takayoshi; Kasuya, Yuki; Itoh, Yukihiro; Ota, Yosuke; Zhan, Peng; Asamitsu, Kaori; Nakagawa, Hidehiko; Okamoto, Takashi; Miyata, Naoki

2013-01-01

To find histone deacetylase 3 (HDAC3)-selective inhibitors, a series of 504 candidates was assembled using "click chemistry", by reacting nine alkynes bearing a zinc-binding group with 56 azide building blocks in the presence of Cu(I) catalyst. Screening of the 504-member triazole library against HDAC3 and other HDAC isozymes led to the identification of potent and selective HDAC3 inhibitors T247 and T326. These compounds showed potent HDAC3 inhibition with submicromolar IC50s, whereas they did not strongly inhibit other isozymes. Compounds T247 and T326 also induced a dose-dependent selective increase of NF-κB acetylation in human colon cancer HCT116 cells, indicating selective inhibition of HDAC3 in the cells. In addition, these HDAC3-selective inhibitors induced growth inhibition of cancer cells, and activated HIV gene expression in latent HIV-infected cells. These findings indicate that HDAC3-selective inhibitors are promising candidates for anticancer drugs and antiviral agents. This work also suggests the usefulness of the click chemistry approach to find isozyme-selective HDAC inhibitors.

A hit to lead discovery of novel N-methylated imidazolo-, pyrrolo-, and pyrazolo-pyrimidines as potent and selective mTOR inhibitors.

PubMed

Lee, Wendy; Ortwine, Daniel F; Bergeron, Philippe; Lau, Kevin; Lin, Lichuan; Malek, Shiva; Nonomiya, Jim; Pei, Zhonghua; Robarge, Kirk D; Schmidt, Stephen; Sideris, Steve; Lyssikatos, Joseph P

2013-09-15

A series of N-7-methyl-imidazolopyrimidine inhibitors of the mTOR kinase have been designed and prepared, based on the hypothesis that the N-7-methyl substituent on imidazolopyrimidine would impart selectivity for mTOR over the related PI3Kα and δ kinases. The corresponding N-Me substituted pyrrolo[3,2-d]pyrimidines and pyrazolo[4,3-d]pyrimidines also show potent mTOR inhibition with selectivity toward both PI3α and δ kinases. The most potent compound synthesized is pyrazolo[4,3-d]pyrimidine 21c. Compound 21c shows a Ki of 2 nM against mTOR inhibition, remarkable selectivity (>2900×) over PI3 kinases, and excellent potency in cell-based assays. Copyright © 2013 Elsevier Ltd. All rights reserved.

Recent advances in the development of 14-alkoxy substituted morphinans as potent and safer opioid analgesics.

PubMed

Spetea, M; Schmidhammer, H

2012-01-01

Morphine and other opioid morphinans produce analgesia primarily through μ opioid receptors (MORs), which mediate beneficial but also non-beneficial actions. There is a continued search for efficacious opioid analgesics with reduced complications. The cornerstone in the development of 14-alkoxymorphinans as novel analgesic drugs was the synthesis of the highly potent MOR agonist 14-O-methyloxymorphone. This opioid showed high antinociceptive potency but also the adverse effects associated with morphine type compounds. Further developments represent the introduction of a methyl and benzyl group at position 5 of 14-O-methyloxymorphone leading to the strong opioid analgesics 14-methoxymetopon and its 5-benzyl analogue, which exhibited less pronounced side effects than morphine although interacting selectively with MORs. Introduction of arylalkyl substituents such as phenylpropoxy in position 14 led to a series of extremely potent antinociceptive agents with enhanced affinities at all three opioid receptor types. During the past years, medicinal chemistry and opioid research focused increasingly on exploring the therapeutic potential of peripheral opioid receptors by peripheralization of opioids in order to minimize the occurrence of centrally-mediated side effects. Strategies to reduce penetration to the central nervous system (CNS) include chemical modifications that increase hydrophilicity. Zwitterionic 6-amino acid conjugates of 14-Oalkyloxymorphones were developed in an effort to obtain opioid agonists that have limited access to the CNS. These compounds show high antinociceptive potency by interacting with peripheral MORs. Opioid drugs with peripheral site of action represent an important target for the treatment of severe and chronic pain without the adverse actions of centrally acting opioids.

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

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.

Discovery and Structure Enabled Synthesis of 2,6-Diaminopyrimidin-4-one IRAK4 Inhibitors

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

Seganish, W. Michael; Fischmann, Thierry O.; Sherborne, Brad

2015-08-13

We report the identification and synthesis of a series of aminopyrimidin-4-one IRAK4 inhibitors. Through high throughput screening, an aminopyrimidine hit was identified and modified via structure enabled design to generate a new, potent, and kinase selective pyrimidin-4-one chemotype. This chemotype is exemplified by compound 16, which has potent IRAK4 inhibition activity (IC50 = 27 nM) and excellent kinase selectivity (>100-fold against 99% of 111 tested kinases), and compound 31, which displays potent IRAK4 activity (IC50 = 93 nM) and good rat bioavailability (F = 42%).

Development of a potent and selective FLT3 kinase inhibitor by systematic expansion of a non-selective fragment-screening hit.

PubMed

Nakano, Hirofumi; Hasegawa, Tsukasa; Imamura, Riyo; Saito, Nae; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo

2016-05-01

A non-selective inhibitor (1) of FMS-like tyrosine kinase-3 (FLT3) was identified by fragment screening and systematically modified to afford a potent and selective inhibitor 26. We confirmed that 26 inhibited the growth of FLT-3-activated human acute myeloid leukemia cell line MV4-11. Our design strategy enabled rapid development of a novel type of FLT3 inhibitor from the hit fragment in the absence of target-structural information. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

An exceptionally potent inducer of cytoprotective enzymes: elucidation of the structural features that determine inducer potency and reactivity with Keap1.

PubMed

Dinkova-Kostova, Albena T; Talalay, Paul; Sharkey, John; Zhang, Ying; Holtzclaw, W David; Wang, Xiu Jun; David, Emilie; Schiavoni, Katherine H; Finlayson, Stewart; Mierke, Dale F; Honda, Tadashi

2010-10-29

The Keap1/Nrf2/ARE pathway controls a network of cytoprotective genes that defend against the damaging effects of oxidative and electrophilic stress, and inflammation. Induction of this pathway is a highly effective strategy in combating the risk of cancer and chronic degenerative diseases, including atherosclerosis and neurodegeneration. An acetylenic tricyclic bis(cyano enone) bearing two highly electrophilic Michael acceptors is an extremely potent inducer in cells and in vivo. We demonstrate spectroscopically that both cyano enone functions of the tricyclic molecule react with cysteine residues of Keap1 and activate transcription of cytoprotective genes. Novel monocyclic cyano enones, representing fragments of rings A and C of the tricyclic compound, reveal that the contribution to inducer potency of the ring C Michael acceptor is much greater than that of ring A, and that potency is further enhanced by spatial proximity of an acetylenic function. Critically, the simultaneous presence of two cyano enone functions in rings A and C within a rigid three-ring system results in exceptionally high inducer potency. Detailed understanding of the structural elements that contribute to the reactivity with the protein sensor Keap1 and to high potency of induction is essential for the development of specific and selective lead compounds as clinically relevant chemoprotective agents.

A Review of the Current Research Trends in the Application of Medicinal Plants as a Source for Novel Therapeutic Agents Against Acanthamoeba Infections

PubMed Central

Niyyati, Maryam; Dodangeh, Samira; Lorenzo-Morales, Jacob

2016-01-01

Acanthamoeba keratitis (AK) is a sight-threating infection of the cornea that mostly affects contact lens wearers. Until now, AK treatment remains very difficult due to the existence of a highly resistant cyst stage in the life cycle of Acanthamoeba which is extremely resistant to most of the available anti-amoebic compounds. Moreover, current treatment of AK is usually based in the combination of various therapeutic agents such as polyhexamethylene biguanide or chlorhexidine and propamidine isethionate. However, all the mentioned compounds have also showed toxic side effects on human keratocytes and presented poor cysticidal effect at the concentrations currently used in the established AK treatments. Nowadays, the elucidation of novel compounds with antimicrobial and anticancer properties from plant and herbs with medicinal properties have encouraged researchers to evaluate plants as a source of new molecules with anti-trophozoite and cysticidal effects. Thus, in recent years, many natural products have been reported to present potent anti-Acanthamoeba properties with good selectivity and minimal toxic effects. Therefore, the chemical drugs currently used for AK treatment, their drawbacks as well as the current research in medicinal plants as a source of potent anti-Acanthamoeba compounds are described in this review. PMID:28243287

Anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize.

PubMed

Adams, Stephen R; Yang, Howard C; Savariar, Elamprakash N; Aguilera, Joe; Crisp, Jessica L; Jones, Karra A; Whitney, Michael A; Lippman, Scott M; Cohen, Ezra E W; Tsien, Roger Y; Advani, Sunil J

2016-10-04

Tumour resistance to radiotherapy remains a barrier to improving cancer patient outcomes. To overcome radioresistance, certain drugs have been found to sensitize cells to ionizing radiation (IR). In theory, more potent radiosensitizing drugs should increase tumour kill and improve patient outcomes. In practice, clinical utility of potent radiosensitizing drugs is curtailed by off-target side effects. Here we report potent anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize to tumours based on surface receptor expression. While two classes of potent anti-tubulins, auristatins and maytansinoids, indiscriminately radiosensitize tumour cells, conjugating these potent anti-tubulins to anti-ErbB antibodies restrict their radiosensitizing capacity. Of translational significance, we report that a clinically used maytansinoid ADC, ado-trastuzumab emtansine (T-DM1), with IR prolongs tumour control in target expressing HER2+ tumours but not target negative tumours. In contrast to ErbB signal inhibition, our findings establish an alternative therapeutic paradigm for ErbB-based radiosensitization using antibodies to restrict radiosensitizer delivery.

Anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize

PubMed Central

Adams, Stephen R.; Yang, Howard C.; Savariar, Elamprakash N.; Aguilera, Joe; Crisp, Jessica L.; Jones, Karra A.; Whitney, Michael A.; Lippman, Scott M.; Cohen, Ezra E. W.; Tsien, Roger Y.; Advani, Sunil J.

2016-01-01

Tumour resistance to radiotherapy remains a barrier to improving cancer patient outcomes. To overcome radioresistance, certain drugs have been found to sensitize cells to ionizing radiation (IR). In theory, more potent radiosensitizing drugs should increase tumour kill and improve patient outcomes. In practice, clinical utility of potent radiosensitizing drugs is curtailed by off-target side effects. Here we report potent anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize to tumours based on surface receptor expression. While two classes of potent anti-tubulins, auristatins and maytansinoids, indiscriminately radiosensitize tumour cells, conjugating these potent anti-tubulins to anti-ErbB antibodies restrict their radiosensitizing capacity. Of translational significance, we report that a clinically used maytansinoid ADC, ado-trastuzumab emtansine (T-DM1), with IR prolongs tumour control in target expressing HER2+ tumours but not target negative tumours. In contrast to ErbB signal inhibition, our findings establish an alternative therapeutic paradigm for ErbB-based radiosensitization using antibodies to restrict radiosensitizer delivery. PMID:27698471

Purine derivatives as potent Bruton’s tyrosine kinase (BTK) inhibitors for autoimmune diseases

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

Shi, Qing; Tebben, Andrew; Dyckman, Alaric J.

Investigation of various heterocyclic core isosteres of imidazopyrazines 1 & 2 yielded purine derivatives 3 & 8 as potent and selective BTK inhibitors. Subsequent SAR studies of the purine series led to the discovery of 20 as a leading compound. Compound 20 is very selective when screened against a panel of 400 kinases and is a potent inhibitor in cellular assays of human B cell function including B-Cell proliferation and CD86 cell surface expression and exhibited in vivo efficacy in a mouse PCA model. Its X-ray co-crystal structure with BTK shows that the high selectivity is gained from filling amore » BTK specific lipophilic pocket. However, physical and ADME properties leading to low oral exposure hindered further development.« less

Environmental and Metabolic Transformations of the Piscicide Antimycin A

EPA Science Inventory

Antimycin A is a natural occurring product of bacterial fermentation and is an extremely potent inhibitor of mitochondrial respiration. It is toxic to all organisms that depend on mitochondrial respiration; however, there is a large divergence in toxicity, even between closely re...

Discovery of a Potent, Selective T-type Calcium Channel Blocker as a Drug Candidate for the Treatment of Generalized Epilepsies.

PubMed

Bezençon, Olivier; Heidmann, Bibia; Siegrist, Romain; Stamm, Simon; Richard, Sylvia; Pozzi, Davide; Corminboeuf, Olivier; Roch, Catherine; Kessler, Melanie; Ertel, Eric A; Reymond, Isabelle; Pfeifer, Thomas; de Kanter, Ruben; Toeroek-Schafroth, Michael; Moccia, Luca G; Mawet, Jacques; Moon, Richard; Rey, Markus; Capeleto, Bruno; Fournier, Elvire

2017-12-14

We report here the discovery and pharmacological characterization of N-(1-benzyl-1H-pyrazol-3-yl)-2-phenylacetamide derivatives as potent, selective, brain-penetrating T-type calcium channel blockers. Optimization focused mainly on solubility, brain penetration, and the search for an aminopyrazole metabolite that would be negative in an Ames test. This resulted in the preparation and complete characterization of compound 66b (ACT-709478), which has been selected as a clinical candidate.

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.

Discovery of Potent and Selective Inhibitors for G9a-Like Protein (GLP) Lysine Methyltransferase

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

Xiong, Yan; Li, Fengling; Babault, Nicolas

G9a-like protein (GLP) and G9a are highly homologous protein lysine methyltransferases (PKMTs) sharing approximately 80% sequence identity in their catalytic domains. GLP and G9a form a heterodimer complex and catalyze mono- and dimethylation of histone H3 lysine 9 and nonhistone substrates. Although they are closely related, GLP and G9a possess distinct physiological and pathophysiological functions. Thus, GLP or G9a selective small-molecule inhibitors are useful tools to dissect their distinct biological functions. We previously reported potent and selective G9a/GLP dual inhibitors including UNC0638 and UNC0642. Here we report the discovery of potent and selective GLP inhibitors including 4 (MS0124) and 18more » (MS012), which are >30-fold and 140-fold selective for GLP over G9a and other methyltransferases, respectively. The cocrystal structures of GLP and G9a in the complex with either 4 or 18 displayed virtually identical binding modes and interactions, highlighting the challenges in structure-based design of selective inhibitors for either enzyme.« less

Plasmin substrate binding site cooperativity guides the design of potent peptide aldehyde inhibitors.

PubMed

Swedberg, Joakim E; Harris, Jonathan M

2011-10-04

Perioperative bleeding is a cause of major blood loss and is associated with increased rates of postoperative morbidity and mortality. To combat this, antifibrinolytic inhibitors of the serine protease plasmin are commonly used to reduce bleeding during surgery. The most effective and previously widely used of these is the broad range serine protease inhibitor aprotinin. However, adverse clinical outcomes have led to use of alternative serine lysine analogues to inhibit plasmin. These compounds suffer from low selectivity and binding affinity. Consequently, a concerted effort to discover potent and selective plasmin inhibitors has developed. This study used a noncombinatorial peptide library to define plasmin's extended substrate specificity and guide the design of potent transition state analogue inhibitors. The various substrate binding sites of plasmin were found to exhibit a higher degree of cooperativity than had previously been appreciated. Peptide sequences capitalizing on these features produced high-affinity inhibitors of plasmin. The most potent of these, Lys-Met(sulfone)-Tyr-Arg-H [KM(O(2))YR-H], inhibited plasmin with a K(i) of 3.1 nM while maintaining 25-fold selectivity over plasma kallikrein. Furthermore, 125 nM (0.16 μg/mL) KM(O(2))YR-H attenuated fibrinolysis in vitro with an efficacy similar to that of 15 nM (0.20 μg/mL) aprotinin. To date, this is the most potent peptide inhibitor of plasmin that exhibits selectivity against plasma kallikrein, making this compound an attractive candidate for further therapeutic development.

Effect of a novel selective and potent phosphinic peptide inhibitor of endopeptidase 3.4.24.16 on neurotensin-induced analgesia and neuronal inactivation.

PubMed

Vincent, B; Jiracek, J; Noble, F; Loog, M; Roques, B; Dive, V; Vincent, J P; Checler, F

1997-06-01

1. We have examined a series of novel phosphinic peptides as putative potent and selective inhibitors of endopeptidase 3.4.24.16. 2. The most selective inhibitor, Pro-Phe-psi(PO2CH2)-Leu-Pro-NH2 displayed a Ki value of 12 nM towards endopeptidase 3.4.24.16 and was 5540 fold less potent on its related peptidase endopeptidase 3.4.24.15. Furthermore, this inhibitor was 12.5 less potent on angiotensin-converting enzyme and was unable to block endopeptidase 3.4.24.11, aminopeptidases B and M, dipeptidylaminopeptidase IV and proline endopeptidase. 3. The effect of Pro-Phe-psi(PO2CH2)-Leu-Pro-NH2, in vitro and in vivo, on neurotensin metabolism in the central nervous system was examined. 4. Pro-Phe-psi(PO2CHH2)-Leu-Pro-NH2 dose-dependently inhibited the formation of neurotensin 1-10 and concomittantly protected neurotensin from degradation by primary cultured neurones from mouse embryos. 5. Intracerebroventricular administration of Pro-Phe-psi(PO2CH2)-Leu-Pro-NH2 significantly potentiated the neurotensin-induced antinociception of mice in the hot plate test. 6. Altogether, our study has established Pro-Phe-psi(PO2CH2)-Leu-Pro-NH2 as a fully selective and highly potent inhibitor of endopeptidase 3.4.24.16 and demonstrates, for the first time, the contribution of this enzyme in the central metabolism of neurotensin.

Effect of a novel selective and potent phosphinic peptide inhibitor of endopeptidase 3.4.24.16 on neurotensin-induced analgesia and neuronal inactivation

PubMed Central

Vincent, Bruno; Jiracek, Jirì; Noble, Florence; Loog, Mart; Roques, Bernard; Dive, Vincent; Vincent, Jean-Pierre; Checler, Frédéric

1997-01-01

We have examined a series of novel phosphinic peptides as putative potent and selective inhibitors of endopeptidase 3.4.24.16. The most selective inhibitor, Pro-Phe-Ψ(PO2CH2)-Leu-Pro-NH2 displayed a Ki value of 12 nM towards endopeptidase 3.4.24.16 and was 5540 fold less potent on its related peptidase endopeptidase 3.4.24.15. Furthermore, this inhibitor was 12.5 less potent on angiotensin-converting enzyme and was unable to block endopeptidase 3.4.24.11, aminopeptidases B and M, dipeptidylaminopeptidase IV and proline endopeptidase. The effect of Pro-Phe-Ψ(PO2CH2)-Leu-Pro-NH2, in vitro and in vivo, on neurotensin metabolism in the central nervous system was examined. Pro-Phe-Ψ(PO2CHH2)-Leu-Pro-NH2 dose-dependently inhibited the formation of neurotensin 1-10 and concomittantly protected neurotensin from degradation by primary cultured neurones from mouse embryos. Intracerebroventricular administration of Pro-Phe-Ψ(PO2CH2)-Leu-Pro-NH2 significantly potentiated the neurotensin-induced antinociception of mice in the hot plate test. Altogether, our study has established Pro-Phe-Ψ(PO2CH2)-Leu-Pro-NH2 as a fully selective and highly potent inhibitor of endopeptidase 3.4.24.16 and demonstrates, for the first time, the contribution of this enzyme in the central metabolism of neurotensin. PMID:9208137

Cell selection and characterization of a novel human endothelial cell specific nanobody.

PubMed

Ahmadvand, Davoud; Rasaee, Mohammad J; Rahbarizadeh, Fatemeh; Kontermann, Roland E; Sheikholislami, Farzaneh

2009-05-01

Antibody-based targeting of angiogenesis and vascular targeting therapy of cancer are extremely attractive conceptually and open new important diagnostic and therapeutic opportunities. Compelling evidence suggests that CD105 represents an ideal target for anti-angiogenic therapy and its presence in solid tumor vasculature has prognostic value. Camelids produce functional antibodies devoid of light chains and constant heavy chain domain (CH1). Nanobodies, the antigen-binding fragments of such heavy chain antibodies, are therefore comprised in one single domain. The aim of this study was to explore the possibilities of using anti-endoglin nanobody as an angiogenesis inhibitor. The anti-CD105 nanobody (AR-86a) was isolated from immune library by selections on purified antigens and target cells. Immunocytochemistry and FACS analysis showed that the purified nanobody reacted specifically with human umbilical vein endothelial cells (HUVECs) but not with other cell lines such as MDA-MB-453, Mel III, T-47D, MCF-7, AGO and HT 29. Further, selected nanobody potently inhibited proliferation of human endothelial cells and formation of capillary-like structures. This selected high affinity anti-endoglin nanobody may offer high specificity towards tumors with reduced side effects, and may be less likely to elicit drug resistance compared to conventional therapy.

Three-Fingered RAVERs: Rapid Accumulation of Variations in Exposed Residues of Snake Venom Toxins

PubMed Central

Sunagar, Kartik; Jackson, Timothy N. W.; Undheim, Eivind A. B.; Ali, Syed. A.; Antunes, Agostinho; Fry, Bryan G.

2013-01-01

Three-finger toxins (3FTx) represent one of the most abundantly secreted and potently toxic components of colubrid (Colubridae), elapid (Elapidae) and psammophid (Psammophiinae subfamily of the Lamprophidae) snake venom arsenal. Despite their conserved structural similarity, they perform a diversity of biological functions. Although they are theorised to undergo adaptive evolution, the underlying diversification mechanisms remain elusive. Here, we report the molecular evolution of different 3FTx functional forms and show that positively selected point mutations have driven the rapid evolution and diversification of 3FTx. These diversification events not only correlate with the evolution of advanced venom delivery systems (VDS) in Caenophidia, but in particular the explosive diversification of the clade subsequent to the evolution of a high pressure, hollow-fanged VDS in elapids, highlighting the significant role of these toxins in the evolution of advanced snakes. We show that Type I, II and III α-neurotoxins have evolved with extreme rapidity under the influence of positive selection. We also show that novel Oxyuranus/Pseudonaja Type II forms lacking the apotypic loop-2 stabilising cysteine doublet characteristic of Type II forms are not phylogenetically basal in relation to other Type IIs as previously thought, but are the result of secondary loss of these apotypic cysteines on at least three separate occasions. Not all 3FTxs have evolved rapidly: κ-neurotoxins, which form non-covalently associated heterodimers, have experienced a relatively weaker influence of diversifying selection; while cytotoxic 3FTx, with their functional sites, dispersed over 40% of the molecular surface, have been extremely constrained by negative selection. We show that the a previous theory of 3FTx molecular evolution (termed ASSET) is evolutionarily implausible and cannot account for the considerable variation observed in very short segments of 3FTx. Instead, we propose a theory of Rapid Accumulation of Variations in Exposed Residues (RAVER) to illustrate the significance of point mutations, guided by focal mutagenesis and positive selection in the evolution and diversification of 3FTx. PMID:24253238

Ancient Diversification of Three-Finger Toxins in Micrurus Coral Snakes.

PubMed

Dashevsky, Daniel; Fry, Bryan G

2018-01-01

Coral snakes, most notably the genus Micrurus, are the only terrestrial elapid snakes in the Americas. Elapid venoms are generally known for their potent neurotoxicity which is usually caused by Three-Finger Toxin (3FTx) proteins. These toxins can have a wide array of functions that have been characterized from the venom of other elapids. We examined publicly available sequences from Micrurus 3FTx to show that they belong to 8 monophyletic clades that diverged as deep in the 3FTx phylogenetic tree as the other clades with characterized functions. Functional residues from previously characterized clades of 3FTx are not well conserved in most of the Micrurus toxin clades. We also analyzed the patterns of selection on these toxins and find that they have been diversifying at different rates, with some having undergone extreme diversifying selection. This suggests that Micrurus 3FTx may contain a previously underappreciated functional diversity that has implications for the clinical outcomes of bite victims, the evolution and ecology of the genus, as well as the potential for biodiscovery efforts focusing on these toxins.

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.

Design and synthesis of carbazole carboxamides as promising inhibitors of Bruton’s tyrosine kinase (BTK) and Janus kinase 2 (JAK2)

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

Liu, Qingjie; Batt, Douglas G.; Lippy, Jonathan S.

Four series of disubstituted carbazole-1-carboxamides were designed and synthesised as inhibitors of Bruton’s tyrosine kinase (BTK). 4,7- and 4,6-disubstituted carbazole-1-carboxamides were potent and selective inhibitors of BTK, while 3,7- and 3,6-disubstituted carbazole-1-carboxamides were potent and selective inhibitors of Janus kinase 2 (JAK2).

Natural products with health benefits from marine biological resources

USDA-ARS?s Scientific Manuscript database

The ocean is the cradle of lives, which provides a diverse array of intriguing natural products that has captured scientists’ attention in the past few decades due to their significant and extremely potent biological activities. In addition to being rich sources for pharmaceutical drugs, marine nat...

Structure-Based Approach To Identify 5-[4-Hydroxyphenyl]pyrrole-2-carbonitrile Derivatives as Potent and Tissue Selective Androgen Receptor Modulators.

PubMed

Unwalla, Ray; Mousseau, James J; Fadeyi, Olugbeminiyi O; Choi, Chulho; Parris, Kevin; Hu, Baihua; Kenney, Thomas; Chippari, Susan; McNally, Christopher; Vishwanathan, Karthick; Kilbourne, Edward; Thompson, Catherine; Nagpal, Sunil; Wrobel, Jay; Yudt, Matthew; Morris, Carl A; Powell, Dennis; Gilbert, Adam M; Chekler, Eugene L Piatnitski

2017-07-27

In an effort to find new and safer treatments for osteoporosis and frailty, we describe a novel series of selective androgen receptor modulators (SARMs). Using a structure-based approach, we identified compound 7, a potent AR (ARE EC 50 = 0.34 nM) and selective (N/C interaction EC 50 = 1206 nM) modulator. In vivo data, an AR LBD X-ray structure of 7, and further insights from modeling studies of ligand receptor interactions are also presented.

Investigations on the 4-Quinolone-3-Carboxylic Acid Motif. 5. Modulation of the Physicochemical Profile of a Set of Potent and Selective Cannabinoid-2 Receptor Ligands through a Bioisosteric Approach

PubMed Central

Nocerino, Stefania; Pedani, Valentina; Pasquini, Serena; Tafi, Andrea; De Chiaro, Maria; Bellucci, Luca; Valoti, Massimo; Guida, Francesca; Luongo, Livio; Dragoni, Stefania; Ligresti, Alessia; Rosenberg, Avraham; Bolognini, Daniele; Cascio, Maria Grazia; Pertwee, Roger G.; Moaddel, Ruin; Maione, Sabatino; Di Marzo, Vincenzo

2012-01-01

Three heterocyclic systems were selected as potential surrogates of the amide linker for a series of 1,6-disubstituted-4-quinolone-3-carboxamides, potent and selective CB2 ligands exhibiting scarce water solubility, with the aim of improving their physicochemical profile and also of clarifying properties of importance for amide bond mimicry. Among the newly synthesized compounds, the 1,2,3-triazole derivative 11 emerged as the most promising in terms of both physicochemical and pharmacodynamic properties. When assayed in vitro, 11 exhibited inverse agonist activity, whereas, in vivo, in the formalin test in mice, it produced analgesic effects antagonized by a well established inverse agonist. Metabolic studies allowed the identification of the side chain hydroxylated derivative 32 as its only metabolite which, in its racemic form, showed still appreciable CB2 selectivity, but was 150-fold less potent than the parent compound. PMID:22383251

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

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

Pharmacological characterization of potent and selective NaV1.7 inhibitors engineered from Chilobrachys jingzhao tarantula venom peptide JzTx-V.

PubMed

Moyer, Bryan D; Murray, Justin K; Ligutti, Joseph; Andrews, Kristin; Favreau, Philippe; Jordan, John B; Lee, Josie H; Liu, Dong; Long, Jason; Sham, Kelvin; Shi, Licheng; Stöcklin, Reto; Wu, Bin; Yin, Ruoyuan; Yu, Violeta; Zou, Anruo; Biswas, Kaustav; Miranda, Les P

2018-01-01

Identification of voltage-gated sodium channel NaV1.7 inhibitors for chronic pain therapeutic development is an area of vigorous pursuit. In an effort to identify more potent leads compared to our previously reported GpTx-1 peptide series, electrophysiology screening of fractionated tarantula venom discovered the NaV1.7 inhibitory peptide JzTx-V from the Chinese earth tiger tarantula Chilobrachys jingzhao. The parent peptide displayed nominal selectivity over the skeletal muscle NaV1.4 channel. Attribute-based positional scan analoging identified a key Ile28Glu mutation that improved NaV1.4 selectivity over 100-fold, and further optimization yielded the potent and selective peptide leads AM-8145 and AM-0422. NMR analyses revealed that the Ile28Glu substitution changed peptide conformation, pointing to a structural rationale for the selectivity gains. AM-8145 and AM-0422 as well as GpTx-1 and HwTx-IV competed for ProTx-II binding in HEK293 cells expressing human NaV1.7, suggesting that these NaV1.7 inhibitory peptides interact with a similar binding site. AM-8145 potently blocked native tetrodotoxin-sensitive (TTX-S) channels in mouse dorsal root ganglia (DRG) neurons, exhibited 30- to 120-fold selectivity over other human TTX-S channels and exhibited over 1,000-fold selectivity over other human tetrodotoxin-resistant (TTX-R) channels. Leveraging NaV1.7-NaV1.5 chimeras containing various voltage-sensor and pore regions, AM-8145 mapped to the second voltage-sensor domain of NaV1.7. AM-0422, but not the inactive peptide analog AM-8374, dose-dependently blocked capsaicin-induced DRG neuron action potential firing using a multi-electrode array readout and mechanically-induced C-fiber spiking in a saphenous skin-nerve preparation. Collectively, AM-8145 and AM-0422 represent potent, new engineered NaV1.7 inhibitory peptides derived from the JzTx-V scaffold with improved NaV selectivity and biological activity in blocking action potential firing in both DRG neurons and C-fibers.

Pharmacological characterization of potent and selective NaV1.7 inhibitors engineered from Chilobrachys jingzhao tarantula venom peptide JzTx-V

PubMed Central

Murray, Justin K.; Ligutti, Joseph; Andrews, Kristin; Favreau, Philippe; Jordan, John B.; Lee, Josie H.; Liu, Dong; Long, Jason; Sham, Kelvin; Shi, Licheng; Stöcklin, Reto; Wu, Bin; Yin, Ruoyuan; Yu, Violeta; Zou, Anruo; Biswas, Kaustav; Miranda, Les P.

2018-01-01

Identification of voltage-gated sodium channel NaV1.7 inhibitors for chronic pain therapeutic development is an area of vigorous pursuit. In an effort to identify more potent leads compared to our previously reported GpTx-1 peptide series, electrophysiology screening of fractionated tarantula venom discovered the NaV1.7 inhibitory peptide JzTx-V from the Chinese earth tiger tarantula Chilobrachys jingzhao. The parent peptide displayed nominal selectivity over the skeletal muscle NaV1.4 channel. Attribute-based positional scan analoging identified a key Ile28Glu mutation that improved NaV1.4 selectivity over 100-fold, and further optimization yielded the potent and selective peptide leads AM-8145 and AM-0422. NMR analyses revealed that the Ile28Glu substitution changed peptide conformation, pointing to a structural rationale for the selectivity gains. AM-8145 and AM-0422 as well as GpTx-1 and HwTx-IV competed for ProTx-II binding in HEK293 cells expressing human NaV1.7, suggesting that these NaV1.7 inhibitory peptides interact with a similar binding site. AM-8145 potently blocked native tetrodotoxin-sensitive (TTX-S) channels in mouse dorsal root ganglia (DRG) neurons, exhibited 30- to 120-fold selectivity over other human TTX-S channels and exhibited over 1,000-fold selectivity over other human tetrodotoxin-resistant (TTX-R) channels. Leveraging NaV1.7-NaV1.5 chimeras containing various voltage-sensor and pore regions, AM-8145 mapped to the second voltage-sensor domain of NaV1.7. AM-0422, but not the inactive peptide analog AM-8374, dose-dependently blocked capsaicin-induced DRG neuron action potential firing using a multi-electrode array readout and mechanically-induced C-fiber spiking in a saphenous skin-nerve preparation. Collectively, AM-8145 and AM-0422 represent potent, new engineered NaV1.7 inhibitory peptides derived from the JzTx-V scaffold with improved NaV selectivity and biological activity in blocking action potential firing in both DRG neurons and C-fibers. PMID:29723257

Discovery of Potent and Selective Agonists of δ Opioid Receptor by Revisiting the "Message-Address" Concept.

PubMed

Shen, Qing; Qian, Yuanyuan; Huang, Xiaoqin; Xu, Xuejun; Li, Wei; Liu, Jinggen; Fu, Wei

2016-04-14

The classic "message-address" concept was proposed to address the binding of endogenous peptides to the opioid receptors and was later successfully applied in the discovery of the first nonpeptide δ opioid receptor (DOR) antagonist naltrindole. By revisiting this concept, and based on the structure of tramadol, we designed a series of novel compounds that act as highly potent and selective agonists of DOR among which (-)-6j showed the highest affinity (K i = 2.7 nM), best agonistic activity (EC50 = 2.6 nM), and DOR selectivity (more than 1000-fold over the other two subtype opioid receptors). Molecular docking studies suggest that the "message" part of (-)-6j interacts with residue Asp128(3.32) and a neighboring water molecule, and the "address" part of (-)-6j packs with hydrophobic residues Leu300(7.35), Val281(6.55), and Trp284(6.58), rendering DOR selectivity. The discovery of novel compound (-)-6j, and the obtained insights into DOR-agonist binding will help us design more potent and selective DOR agonists.

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.

Biosynthesis of ilamycins featuring unusual building blocks and engineered production of enhanced anti-tuberculosis agents.

PubMed

Ma, Junying; Huang, Hongbo; Xie, Yunchang; Liu, Zhiyong; Zhao, Jin; Zhang, Chunyan; Jia, Yanxi; Zhang, Yun; Zhang, Hua; Zhang, Tianyu; Ju, Jianhua

2017-08-30

Tuberculosis remains one of the world's deadliest communicable diseases, novel anti-tuberculosis agents are urgently needed due to severe drug resistance and the co-epidemic of tuberculosis/human immunodeficiency virus. Here, we show the isolation of six anti-mycobacterial ilamycin congeners (1-6) bearing rare L-3-nitro-tyrosine and L-2-amino-4-hexenoic acid structural units from the deep sea-derived Streptomyces atratus SCSIO ZH16. The biosynthesis of the rare L-3-nitrotyrosine and L-2-amino-4-hexenoic acid units as well as three pre-tailoring and two post-tailoring steps are probed in the ilamycin biosynthetic machinery through a series of gene inactivation, precursor chemical complementation, isotope-labeled precursor feeding experiments, as well as structural elucidation of three intermediates (6-8) from the respective mutants. Most impressively, ilamycins E 1 /E 2 , which are produced in high titers by a genetically engineered mutant strain, show very potent anti-tuberculosis activity with an minimum inhibitory concentration value ≈9.8 nM to Mycobacterium tuberculosis H37Rv constituting extremely potent and exciting anti-tuberculosis drug leads.Tuberculosis (TB) remains one of the world's deadliest communicable diseases, novel anti-TB agents are urgently needed due to severe drug resistance and the co-epidemic of TB/HIV. Here, the authors show that anti-mycobacterial ilamycin congeners bearing unusual structural units possess extremely potent anti-tuberculosis activities.

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

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.

Identification of an imidazopyridine scaffold to generate potent and selective TYK2 inhibitors that demonstrate activity in an in vivo psoriasis model.

PubMed

Liang, Jun; Van Abbema, Anne; Balazs, Mercedesz; Barrett, Kathy; Berezhkovsky, Leo; Blair, Wade S; Chang, Christine; Delarosa, Donnie; DeVoss, Jason; Driscoll, Jim; Eigenbrot, Charles; Goodacre, Simon; Ghilardi, Nico; MacLeod, Calum; Johnson, Adam; Bir Kohli, Pawan; Lai, Yingjie; Lin, Zhonghua; Mantik, Priscilla; Menghrajani, Kapil; Nguyen, Hieu; Peng, Ivan; Sambrone, Amy; Shia, Steven; Smith, Jan; Sohn, Sue; Tsui, Vickie; Ultsch, Mark; Williams, Karen; Wu, Lawren C; Yang, Wenqian; Zhang, Birong; Magnuson, Steven

2017-09-15

Herein we report identification of an imidazopyridine class of potent and selective TYK2 inhibitors, exemplified by prototype 6, through constraint of the rotatable amide bond connecting the pyridine and aryl rings of compound 1. Further optimization led to generation of compound 30 that potently inhibits the TYK2 enzyme and the IL-23 pathway in cells, exhibits selectivity against cellular JAK2 activity, and has good pharmacokinetic properties. In mice, compound 30 demonstrated dose-dependent reduction of IL-17 production in a PK/PD model as well as in an imiquimod-induced psoriasis model. In this efficacy model, the IL-17 decrease was accompanied by a reduction of ear thickness indicating the potential of TYK2 inhibition as a therapeutic approach for psoriasis patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Design, synthesis, and evaluation of cyclic amide/imide-bearing hydroxamic acid derivatives as class-selective histone deacetylase (HDAC) inhibitors.

PubMed

Shinji, Chihiro; Maeda, Satoko; Imai, Keisuke; Yoshida, Minoru; Hashimoto, Yuichi; Miyachi, Hiroyuki

2006-11-15

A series of hydroxamic acid derivatives bearing a cyclic amide/imide group as a linker and/or cap structure, prepared during our structural development studies based on thalidomide, showed class-selective potent histone deacetylase (HDAC)-inhibitory activity. Structure-activity relationship studies indicated that the steric character of the substituent introduced at the cyclic amide/imide nitrogen atom, the presence of the amide/imide carbonyl group, the hydroxamic acid structure, the shape of the linking group, and the distance between the zinc-binding hydroxamic acid group and the cap structure are all important for HDAC-inhibitory activity and class selectivity. A representative compound (30w) showed potent p21 promoter activity, comparable with that of trichostatin A (TSA), and its cytostatic activity against cells of the human prostate cell line LNCaP was more potent than that of the well-known HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA).

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.

Promoting Online Voices for Countering Violent Extremism

DTIC Science & Technology

2013-01-01

effective outreach), and being viewed as sell-outs to...Internet.6 The White House recognizes that some of the most effective , potent, and credible messages against al-Qa’ida and other Muslim extremist...provide an effective counternarrative abroad.7 The White House strategy seeks to encourage and empower credible, authentic, and constructive

Closed-loop control of cellular functions using combinatory drugs guided by a stochastic search algorithm

PubMed Central

Wong, Pak Kin; Yu, Fuqu; Shahangian, Arash; Cheng, Genhong; Sun, Ren; Ho, Chih-Ming

2008-01-01

A mixture of drugs is often more effective than using a single effector. However, it is extremely challenging to identify potent drug combinations by trial and error because of the large number of possible combinations and the inherent complexity of the underlying biological network. With a closed-loop optimization modality, we experimentally demonstrate effective searching for potent drug combinations for controlling cellular functions through a large parametric space. Only tens of iterations out of one hundred thousand possible trials were needed to determine a potent combination of drugs for inhibiting vesicular stomatitis virus infection of NIH 3T3 fibroblasts. In addition, the drug combination reduced the required dosage by ≈10-fold compared with individual drugs. In another example, a potent mixture was identified in thirty iterations out of a possible million combinations of six cytokines that regulate the activity of nuclear factor kappa B in 293T cells. The closed-loop optimization approach possesses the potential of being an effective approach for manipulating a wide class of biological systems. PMID:18356295

Identification and Structure-Function Analysis of Subfamily Selective G Protein-Coupled Receptor Kinase Inhibitors

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

Homan, Kristoff T.; Larimore, Kelly M.; Elkins, Jonathan M.

2015-02-13

Selective inhibitors of individual subfamilies of G protein-coupled receptor kinases (GRKs) would serve as useful chemical probes as well as leads for therapeutic applications ranging from heart failure to Parkinson’s disease. To identify such inhibitors, differential scanning fluorimetry was used to screen a collection of known protein kinase inhibitors that could increase the melting points of the two most ubiquitously expressed GRKs: GRK2 and GRK5. Enzymatic assays on 14 of the most stabilizing hits revealed that three exhibit nanomolar potency of inhibition for individual GRKs, some of which exhibiting orders of magnitude selectivity. Most of the identified compounds can bemore » clustered into two chemical classes: indazole/dihydropyrimidine-containing compounds that are selective for GRK2 and pyrrolopyrimidine-containing compounds that potently inhibit GRK1 and GRK5 but with more modest selectivity. The two most potent inhibitors representing each class, GSK180736A and GSK2163632A, were cocrystallized with GRK2 and GRK1, and their atomic structures were determined to 2.6 and 1.85 Å spacings, respectively. GSK180736A, developed as a Rho-associated, coiled-coil-containing protein kinase inhibitor, binds to GRK2 in a manner analogous to that of paroxetine, whereas GSK2163632A, developed as an insulin-like growth factor 1 receptor inhibitor, occupies a novel region of the GRK active site cleft that could likely be exploited to achieve more selectivity. However, neither compound inhibits GRKs more potently than their initial targets. This data provides the foundation for future efforts to rationally design even more potent and selective GRK inhibitors.« less

Tachykinin receptors in the guinea-pig renal pelvis: activation by exogenous and endogenous tachykinins.

PubMed Central

Maggi, C. A.; Patacchini, R.; Eglezos, A.; Quartara, L.; Giuliani, S.; Giachetti, A.

1992-01-01

1. The contractile response to substance P, neurokinin A, selective agonists for the NK1, NK2 and NK3 tachykinin receptors and the activity of receptor-selective antagonists has been investigated in circular muscle strips of the guinea-pig isolated renal pelvis in the presence of indomethacin (3 microM). 2. Neurokinin A was the most potent agonist tested, being about 32 times more potent than substance P. The action of both substance P and neurokinin A was enhanced by peptidase inhibitors (bestatin, captopril and thiorphan, 1 microM each). The selective NK2 receptor agonist [beta Ala8] neurokinin A (4-10), was slightly less potent and effective than neurokinin A itself. The selective NK1 receptor agonist [Sar9] substance P sulphone was effective at low (nM) concentrations but its maximal effect did not exceed 30% of maximal response to substance P or neurokinin A. The NK3-selective agonist [MePhe7] neurokinin B was effective only at high (microM) concentrations. 3. The pseudopeptide derivative of neurokinin A(4-10), MDL 28,564, displayed a clear-cut agonist character, although it was less potent than neurokinin A. 4. The responses to roughly equieffective (25-35% of maximal response) concentrations of [beta Ala8] neurokinin A (4-10), MDL 28,564 and [MePhe7] neurokinin B were antagonized to a similar extent by MEN 10,376 (3 microM), a selective NK2 tachykinin receptor antagonist, while the response to [Sar9] substance P sulphone was unchanged. 5. The response to [Sar9] substance P sulphone was inhibited by the NK1 receptor-selective antagonist, GR 82,334 (3 microM) while the response to [beta Ala8] neurokinin A (4-10) was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1384907

Discovery of a novel class of potent coumarin monoamine oxidase B inhibitors: development and biopharmacological profiling of 7-[(3-chlorobenzyl)oxy]-4-[(methylamino)methyl]-2H-chromen-2-one methanesulfonate (NW-1772) as a highly potent, selective, reversible, and orally active monoamine oxidase B inhibitor.

PubMed

Pisani, Leonardo; Muncipinto, Giovanni; Miscioscia, Teresa Fabiola; Nicolotti, Orazio; Leonetti, Francesco; Catto, Marco; Caccia, Carla; Salvati, Patricia; Soto-Otero, Ramon; Mendez-Alvarez, Estefania; Passeleu, Celine; Carotti, Angelo

2009-11-12

In an effort to discover novel selective monoamine oxidase (MAO) B inhibitors with favorable physicochemical and pharmacokinetic profiles, 7-[(m-halogeno)benzyloxy]coumarins bearing properly selected polar substituents at position 4 were designed, synthesized, and evaluated as MAO inhibitors. Several compounds with MAO-B inhibitory activity in the nanomolar range and excellent MAO-B selectivity (selectivity index SI > 400) were identified. Structure-affinity relationships and docking simulations provided valuable insights into the enzyme-inhibitor binding interactions at position 4, which has been poorly explored. Furthermore, computational and experimental studies led to the identification and biopharmacological characterization of 7-[(3-chlorobenzyl)oxy]-4-[(methylamino)methyl]-2H-chromen-2-one methanesulfonate 22b (NW-1772) as an in vitro and in vivo potent and selective MAO-B inhibitor, with rapid blood-brain barrier penetration, short-acting and reversible inhibitory activity, slight inhibition of selected cytochrome P450s, and low in vitro toxicity. On the basis of this preliminary preclinical profile, inhibitor 22b might be viewed as a promising clinical candidate for the treatment of neurodegenerative diseases.

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.

Targeted Drug-Carrying Bacteriophages as Antibacterial Nanomedicines▿

PubMed Central

Yacoby, Iftach; Bar, Hagit; Benhar, Itai

2007-01-01

While the resistance of bacteria to traditional antibiotics is a major public health concern, the use of extremely potent antibacterial agents is limited by their lack of selectivity. As in cancer therapy, antibacterial targeted therapy could provide an opportunity to reintroduce toxic substances to the antibacterial arsenal. A desirable targeted antibacterial agent should combine binding specificity, a large drug payload per binding event, and a programmed drug release mechanism. Recently, we presented a novel application of filamentous bacteriophages as targeted drug carriers that could partially inhibit the growth of Staphylococcus aureus bacteria. This partial success was due to limitations of drug-loading capacity that resulted from the hydrophobicity of the drug. Here we present a novel drug conjugation chemistry which is based on connecting hydrophobic drugs to the phage via aminoglycoside antibiotics that serve as solubility-enhancing branched linkers. This new formulation allowed a significantly larger drug-carrying capacity of the phages, resulting in a drastic improvement in their performance as targeted drug-carrying nanoparticles. As an example for a potential systemic use for potent agents that are limited for topical use, we present antibody-targeted phage nanoparticles that carry a large payload of the hemolytic antibiotic chloramphenicol connected through the aminoglycoside neomycin. We demonstrate complete growth inhibition toward the pathogens Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli with an improvement in potency by a factor of ∼20,000 compared to the free drug. PMID:17404004

Structure-Based Drug Design of Novel Potent and Selective Tetrahydropyrazolo[1,5- a ]pyrazines as ATR Inhibitors

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

Barsanti, Paul A.; Aversa, Robert J.; Jin, Xianming

A saturation strategy focused on improving the selectivity and physicochemical properties of ATR inhibitor HTS hit 1 led to a novel series of highly potent and selective tetrahydropyrazolo[1,5-a]pyrazines. Use of PI3Kα mutants as ATR crystal structure surrogates was instrumental in providing cocrystal structures to guide the medicinal chemistry designs. Detailed DMPK studies involving cyanide and GSH as trapping agents during microsomal incubations, in addition to deuterium-labeled compounds as mechanistic probes uncovered the molecular basis for the observed CYP3A4 TDI in the series.

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.

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.

Discovery of Dinaciclib (SCH 727965): A Potent and Selective Inhibitor of Cyclin-Dependent Kinases

PubMed Central

2010-01-01

Inhibition of cyclin-dependent kinases (CDKs) has emerged as an attractive strategy for the development of novel oncology therapeutics. Herein is described the utilization of an in vivo screening approach with integrated efficacy and tolerability parameters to identify candidate CDK inhibitors with a suitable balance of activity and tolerability. This approach has resulted in the identification of SCH 727965, a potent and selective CDK inhibitor that is currently undergoing clinical evaluation. PMID:24900195

Discovery of Dinaciclib (SCH 727965): A Potent and Selective Inhibitor of Cyclin-Dependent Kinases.

PubMed

Paruch, Kamil; Dwyer, Michael P; Alvarez, Carmen; Brown, Courtney; Chan, Tin-Yau; Doll, Ronald J; Keertikar, Kerry; Knutson, Chad; McKittrick, Brian; Rivera, Jocelyn; Rossman, Randall; Tucker, Greg; Fischmann, Thierry; Hruza, Alan; Madison, Vincent; Nomeir, Amin A; Wang, Yaolin; Kirschmeier, Paul; Lees, Emma; Parry, David; Sgambellone, Nicole; Seghezzi, Wolfgang; Schultz, Lesley; Shanahan, Frances; Wiswell, Derek; Xu, Xiaoying; Zhou, Quiao; James, Ray A; Paradkar, Vidyadhar M; Park, Haengsoon; Rokosz, Laura R; Stauffer, Tara M; Guzi, Timothy J

2010-08-12

Inhibition of cyclin-dependent kinases (CDKs) has emerged as an attractive strategy for the development of novel oncology therapeutics. Herein is described the utilization of an in vivo screening approach with integrated efficacy and tolerability parameters to identify candidate CDK inhibitors with a suitable balance of activity and tolerability. This approach has resulted in the identification of SCH 727965, a potent and selective CDK inhibitor that is currently undergoing clinical evaluation.

Design and Elaboration of a Tractable Tricyclic Scaffold To Synthesize Druglike Inhibitors of Dipeptidyl Peptidase-4 (DPP-4), Antagonists of the C-C Chemokine Receptor Type 5 (CCR5), and Highly Potent and Selective Phosphoinositol-3 Kinase δ (PI3Kδ) Inhibitors.

PubMed

Schwehm, Carolin; Kellam, Barrie; Garces, Aimie E; Hill, Stephen J; Kindon, Nicholas D; Bradshaw, Tracey D; Li, Jin; Macdonald, Simon J F; Rowedder, James E; Stoddart, Leigh A; Stocks, Michael J

2017-02-23

A novel molecular scaffold has been synthesized, and its incorporation into new analogues of biologically active molecules across multiple target classes will be discussed. In these studies, we have shown use of the tricyclic scaffold to synthesize potent inhibitors of the serine peptidase DPP-4, antagonists of the CCR5 receptor, and highly potent and selective PI3K δ isoform inhibitors. We also describe the predicted physicochemical properties of the resulting inhibitors and conclude that the tractable molecular scaffold could have potential application in future drug discovery programs.

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

Lepidopteran HMG-CoA reductase is a potential selective target for pest control

PubMed Central

Li, Yuan-mei; Huang, Juan; Tobe, Stephen S.

2017-01-01

As a consequence of the negative impacts on the environment of some insecticides, discovery of eco-friendly insecticides and target has received global attention in recent years. Sequence alignment and structural comparison of the rate-limiting enzyme HMG-CoA reductase (HMGR) revealed differences between lepidopteran pests and other organisms, which suggested insect HMGR could be a selective insecticide target candidate. Inhibition of JH biosynthesis in vitro confirmed that HMGR inhibitors showed a potent lethal effect on the lepidopteran pest Manduca sexta, whereas there was little effect on JH biosynthesis in Apis mellifera and Diploptera punctata. The pest control application of these inhibitors demonstrated that they can be insecticide candidates with potent ovicidal activity, larvicidal activity and insect growth regulatory effects. The present study has validated that Lepidopteran HMGR can be a potent selective insecticide target, and the HMGR inhibitors (especially type II statins) could be selective insecticide candidates and lead compounds. Furthermore, we demonstrated that sequence alignment, homology modeling and structural comparison may be useful for determining potential enzymes or receptors which can be eco-friendly pesticide  targets. PMID:28133568

Lepidopteran HMG-CoA reductase is a potential selective target for pest control.

PubMed

Li, Yuan-Mei; Kai, Zhen-Peng; Huang, Juan; Tobe, Stephen S

2017-01-01

As a consequence of the negative impacts on the environment of some insecticides, discovery of eco-friendly insecticides and target has received global attention in recent years. Sequence alignment and structural comparison of the rate-limiting enzyme HMG-CoA reductase (HMGR) revealed differences between lepidopteran pests and other organisms, which suggested insect HMGR could be a selective insecticide target candidate. Inhibition of JH biosynthesis in vitro confirmed that HMGR inhibitors showed a potent lethal effect on the lepidopteran pest Manduca sexta , whereas there was little effect on JH biosynthesis in Apis mellifera and Diploptera punctata . The pest control application of these inhibitors demonstrated that they can be insecticide candidates with potent ovicidal activity, larvicidal activity and insect growth regulatory effects. The present study has validated that Lepidopteran HMGR can be a potent selective insecticide target, and the HMGR inhibitors (especially type II statins) could be selective insecticide candidates and lead compounds. Furthermore, we demonstrated that sequence alignment, homology modeling and structural comparison may be useful for determining potential enzymes or receptors which can be eco-friendly pesticide  targets.

Rational Design of a Highly Potent and Selective Peptide Inhibitor of PACE4 by Salt Bridge Interaction with D160 at Position P3.

PubMed

Dianati, Vahid; Shamloo, Azar; Kwiatkowska, Anna; Desjardins, Roxane; Soldera, Armand; Day, Robert; Dory, Yves L

2017-08-08

PACE4, a member of the proprotein convertases (PCs) family of serine proteases, is a validated target for prostate cancer. Our group has developed a potent and selective PACE4 inhibitor: Ac-LLLLRVKR-NH 2 . In seeking for modifications to increase the selectivity of this ligand toward PACE4, we replaced one of its P3 Val methyl groups with a basic group capable of forming a salt bridge with D160 of PACE4. The resulting inhibitor is eight times more potent than the P3 Val parent inhibitor and two times more selective over furin, because the equivalent salt bridge with furin E257 is not optimal. Moreover, the β-branched nature of the new P3 residue favors the extended β-sheet conformation usually associated with substrates of proteases. This work provides new insight for better understanding of β-sheet backbone-backbone interactions between serine proteases and their peptidic ligands. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Discovery of novel, highly potent, and selective quinazoline-2-carboxamide-based matrix metalloproteinase (MMP)-13 inhibitors without a zinc binding group using a structure-based design approach.

PubMed

Nara, Hiroshi; Sato, Kenjiro; Naito, Takako; Mototani, Hideyuki; Oki, Hideyuki; Yamamoto, Yoshio; Kuno, Haruhiko; Santou, Takashi; Kanzaki, Naoyuki; Terauchi, Jun; Uchikawa, Osamu; Kori, Masakuni

2014-11-13

Matrix metalloproteinase-13 (MMP-13) has been implicated to play a key role in the pathology of osteoarthritis. On the basis of X-ray crystallography, we designed a series of potent MMP-13 selective inhibitors optimized to occupy the distinct deep S1' pocket including an adjacent branch. Among them, carboxylic acid inhibitor 21k exhibited excellent potency and selectivity for MMP-13 over other MMPs. An effort to convert compound 21k to the mono sodium salt 38 was promising in all animal species studied. Moreover, no overt toxicity was observed in a preliminary repeat dose oral toxicity study of compound 21k in rats. A single oral dose of compound 38 significantly reduced degradation products (CTX-II) released from articular cartilage into the joint cavity in a rat MIA model in vivo. In this article, we report the discovery of highly potent, selective, and orally bioavailable MMP-13 inhibitors as well as their detailed structure-activity data.

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.

Discovery and gram-scale synthesis of BMS-593214, a potent, selective FVIIa inhibitor

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

Priestley, E. Scott; De Lucca, Indawati; Zhou, Jinglan

A 6-amidinotetrahydroquinoline screening hit was driven to a structurally novel, potent, and selective FVIIa inhibitor through a combination of library synthesis and rational design. An efficient gram-scale synthesis of the active enantiomer BMS-593214 was developed, which required significant optimization of the key Povarov annulation. Importantly, BMS-593214 showed antithrombotic efficacy in a rabbit arterial thrombosis model. A crystal structure of BMS-593214 bound to FVIIa highlights key contacts with Asp 189, Lys 192, and the S2 pocket.

Discovery of Potent and Selective Inhibitors for ADAMTS-4 through DNA-Encoded Library Technology (ELT).

PubMed

Ding, Yun; O'Keefe, Heather; DeLorey, Jennifer L; Israel, David I; Messer, Jeffrey A; Chiu, Cynthia H; Skinner, Steven R; Matico, Rosalie E; Murray-Thompson, Monique F; Li, Fan; Clark, Matthew A; Cuozzo, John W; Arico-Muendel, Christopher; Morgan, Barry A

2015-08-13

The aggrecan degrading metalloprotease ADAMTS-4 has been identified as a novel therapeutic target for osteoarthritis. Here, we use DNA-encoded Library Technology (ELT) to identify novel ADAMTS-4 inhibitors from a DNA-encoded triazine library by affinity selection. Structure-activity relationship studies based on the selection information led to the identification of potent and highly selective inhibitors. For example, 4-(((4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)-6-(((4-methylpiperazin-1-yl)methyl)amino)-1,3,5-triazin-2-yl)amino)methyl)-N-ethyl-N-(m-tolyl)benzamide has IC50 of 10 nM against ADAMTS-4, with >1000-fold selectivity over ADAMT-5, MMP-13, TACE, and ADAMTS-13. These inhibitors have no obvious zinc ligand functionality.

Discovery of Potent and Selective Inhibitors for ADAMTS-4 through DNA-Encoded Library Technology (ELT)

PubMed Central

2015-01-01

The aggrecan degrading metalloprotease ADAMTS-4 has been identified as a novel therapeutic target for osteoarthritis. Here, we use DNA-encoded Library Technology (ELT) to identify novel ADAMTS-4 inhibitors from a DNA-encoded triazine library by affinity selection. Structure–activity relationship studies based on the selection information led to the identification of potent and highly selective inhibitors. For example, 4-(((4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)-6-(((4-methylpiperazin-1-yl)methyl)amino)-1,3,5-triazin-2-yl)amino)methyl)-N-ethyl-N-(m-tolyl)benzamide has IC50 of 10 nM against ADAMTS-4, with >1000-fold selectivity over ADAMT-5, MMP-13, TACE, and ADAMTS-13. These inhibitors have no obvious zinc ligand functionality. PMID:26288689

Discovery and Characterization of a Highly Potent and Selective Aminopyrazoline-Based in Vivo Probe (BAY-598) for the Protein Lysine Methyltransferase SMYD2.

PubMed

Eggert, Erik; Hillig, Roman C; Koehr, Silke; Stöckigt, Detlef; Weiske, Jörg; Barak, Naomi; Mowat, Jeffrey; Brumby, Thomas; Christ, Clara D; Ter Laak, Antonius; Lang, Tina; Fernandez-Montalvan, Amaury E; Badock, Volker; Weinmann, Hilmar; Hartung, Ingo V; Barsyte-Lovejoy, Dalia; Szewczyk, Magdalena; Kennedy, Steven; Li, Fengling; Vedadi, Masoud; Brown, Peter J; Santhakumar, Vijayaratnam; Arrowsmith, Cheryl H; Stellfeld, Timo; Stresemann, Carlo

2016-05-26

Protein lysine methyltransferases have recently emerged as a new target class for the development of inhibitors that modulate gene transcription or signaling pathways. SET and MYND domain containing protein 2 (SMYD2) is a catalytic SET domain containing methyltransferase reported to monomethylate lysine residues on histone and nonhistone proteins. Although several studies have uncovered an important role of SMYD2 in promoting cancer by protein methylation, the biology of SMYD2 is far from being fully understood. Utilization of highly potent and selective chemical probes for target validation has emerged as a concept which circumvents possible limitations of knockdown experiments and, in particular, could result in an improved exploration of drug targets with a complex underlying biology. Here, we report the development of a potent, selective, and cell-active, substrate-competitive inhibitor of SMYD2, which is the first reported inhibitor suitable for in vivo target validation studies in rodents.

Muscarinic receptor subtype selectivity of novel heterocyclic QNB analogues

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

Baumgold, J.; Cohen, V.I.; Paek, R.

1991-01-01

In an effort at synthesizing centrally-active subtype-selective antimuscarinic agents, the authors derivatized QNB (quinuclidinyl benzilate), a potent muscarinic antagonist, by replacing one of the phenyl groups with less lipophilic heterocyclic moieties. The displacement of ({sup 3}H)-N-methyl scopolamine binding by these novel compounds to membranes from cells expressing ml - m4 receptor subtypes was determined. Most of the novel 4-bromo-QNB analogues were potent and slightly selective for ml receptors. The 2-thienyl derivative was the most potent, exhibiting a 2-fold greater potency than BrQNB at ml receptors, and a 4-fold greater potency than BrQNB at ml receptors, and a 4-fold greater potencymore » at m2 receptors. This compound was also considerably less lipophilic than BrQNB as determined from its retention time on C18 reverse phase HPLC. This compound may therefore be useful both for pharmacological studies and as a candidate for a radioiodinated SPECT imaging agent for ml muscarinic receptors in human brain.« less

Chemical probes to potently and selectively inhibit endocannabinoid cellular reuptake.

PubMed

Chicca, Andrea; Nicolussi, Simon; Bartholomäus, Ruben; Blunder, Martina; Aparisi Rey, Alejandro; Petrucci, Vanessa; Reynoso-Moreno, Ines Del Carmen; Viveros-Paredes, Juan Manuel; Dalghi Gens, Marianela; Lutz, Beat; Schiöth, Helgi B; Soeberdt, Michael; Abels, Christoph; Charles, Roch-Philippe; Altmann, Karl-Heinz; Gertsch, Jürg

2017-06-20

The extracellular effects of the endocannabinoids anandamide and 2-arachidonoyl glycerol are terminated by enzymatic hydrolysis after crossing cellular membranes by facilitated diffusion. The lack of potent and selective inhibitors for endocannabinoid transport has prevented the molecular characterization of this process, thus hindering its biochemical investigation and pharmacological exploitation. Here, we report the design, chemical synthesis, and biological profiling of natural product-derived N -substituted 2,4-dodecadienamides as a selective endocannabinoid uptake inhibitor. The highly potent (IC 50 = 10 nM) inhibitor N -(3,4-dimethoxyphenyl)ethyl amide (WOBE437) exerted pronounced cannabinoid receptor-dependent anxiolytic, antiinflammatory, and analgesic effects in mice by increasing endocannabinoid levels. A tailored WOBE437-derived diazirine-containing photoaffinity probe (RX-055) irreversibly blocked membrane transport of both endocannabinoids, providing mechanistic insights into this complex process. Moreover, RX-055 exerted site-specific anxiolytic effects on in situ photoactivation in the brain. This study describes suitable inhibitors to target endocannabinoid membrane trafficking and uncovers an alternative endocannabinoid pharmacology.

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.

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.

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.

Design and optimization of a series of 1-sulfonylpyrazolo[4,3-b]pyridines as selective c-Met inhibitors.

PubMed

Ma, Yuchi; Sun, Guangqiang; Chen, Danqi; Peng, Xia; Chen, Yue-Lei; Su, Yi; Ji, Yinchun; Liang, Jin; Wang, Xin; Chen, Lin; Ding, Jian; Xiong, Bing; Ai, Jing; Geng, Meiyu; Shen, Jingkang

2015-03-12

c-Met has emerged as an attractive target for targeted cancer therapy because of its abnormal activation in many cancer cells. To identify high potent and selective c-Met inhibitors, we started with profiling the potency and in vitro metabolic stability of a reported hit 7. By rational design, a novel sulfonylpyrazolo[4,3-b]pyridine 9 with improved DMPK properties was discovered. Further elaboration of π-π stacking interactions and solvent accessible polar moieties led to a series of highly potent and selective type I c-Met inhibitors. On the basis of in vitro and in vivo pharmacological and pharmacokinetics studies, compound 46 was selected as a preclinical candidate for further anticancer drug development.

Pharmacology of a selective cyclooxygenase-2 inhibitor, HN-56249: a novel compound exhibiting a marked preference for the human enzyme in intact cells.

PubMed

Berg, J; Fellier, H; Christoph, T; Kremminger, P; Hartmann, M; Blaschke, H; Rovensky, F; Towart, R; Stimmeder, D

2000-04-01

HN-56249 (3-(2,4-dichlorothiophenoxy)-4-methylsulfonylamino-benzenesu lfonamide), a highly selective cyclooxygenase (COX)-2 inhibitor, is the prototype of a novel series of COX inhibitors comprising bicyclic arylethersulfonamides; of this series HN-56249 is the most potent and selective human COX-2 inhibitor. HN-56249 inhibited platelet aggregation as a measure of COX-1 activity only moderately (IC50 26.5+/-1.7 microM). In LPS-stimulated monocytic cells the release of prostaglandin (PG) F1alpha as a measure of COX-2 was markedly inhibited (IC50 0.027+/-0.001 microM). Thus, HN-56249 showed an approximately 1000-fold selectivity for COX-2 in intact cells. In whole blood assays HN-56249 showed a potent inhibitory activity for COX-2 (IC50 0.78+/-0.37 microM) only. COX-1 was only weakly inhibited (IC50 867+/-181 microM). Hence, HN-56249 exhibited a greater than 1000-fold selectivity for whole blood COX-2. HN-56249 surpassed the COX-2 selectivities of the COX-2 selective inhibitors 3-cyclohexyloxy-4-methylsulfonylamino-nitrobenzene (NS-398) and 6-(2,4-difluorophenoxy)-5-methyl-sulfonylamino-1-indanone (flosulide) in the intact cell assays by eight- and threefold, respectively, and in the whole blood assays by approximately 40-fold. Following i.v. administration HN-56249 inhibited carrageenan-induced rat paw oedema only moderately (ID50 26.2+/-5.7 mg/kg, mean +/- SEM), approximately tenfold less potent than indomethacin (ID50 2.1+/-0.2 mg/kg, mean +/- SEM). After oral administration HN-56249 reversed thermal hyperalgesia in the carrageenan-induced rat paw oedema test, however, some 30-fold less potently than diclofenac. Comparing the inhibitory potency of HN-56249 against human COX-2 with that against murine COX-2 in intact cells revealed a 300-fold selectivity for the human enzyme. Similar effects were observed with other COX-2-selective arylethersulfonamides. In contrast, non-COX-2-selective arylethersulfonamides, including a highly selective COX-1 inhibitor, inhibited human and murine COX-2 approximately equipotently. In conclusion, HN-56249 is a novel potent and highly selective COX-2 inhibitor with a marked preference for the human COX-2 enzyme in vitro. Despite excellent bioavailability and the long plasma half-life of HN-56249, anti-inflammatory effects in rodents were only moderate. We suggest these differing in vitro-in vivo effects observed could be due to significant inflammatory prostaglandin synthesis by COX-1, or to the genetic differences between human and rodent COX-2, or to both.

TRANSGENERATIONAL AND DEVELOPMENTAL EXPOSURE OF JAPANESE MEDAKA (ORYZIAS LATIPES) TO ETHINYLESTRADIOL RESULTS IN ENDOCRINE AND REPRODUCTIVE DIFFERENCES IN THE RESPONSE TO ETHINYLESTRADIOL AS ADULTS

EPA Science Inventory

17a-Ethinylestradiol (EE), a synthetic estrogen found in birth control pills, has been detected in the effluent of municipal wastewater treatment plants in several countries. Because EE was designed to be extremely potent at the estrogen receptor (ER), environmental exposure to l...

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.

Discovery and quantitative structure-activity relationship study of lepidopteran HMG-CoA reductase inhibitors as selective insecticides.

PubMed

Zang, Yang-Yang; Li, Yuan-Mei; Yin, Yue; Chen, Shan-Shan; Kai, Zhen-Peng

2017-09-01

In a previous study we have demonstrated that insect 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) can be a potential selective insecticide target. Three series of inhibitors were designed on the basis of the difference in HMGR structures from Homo sapiens and Manduca sexta, with the aim of discovering potent selective insecticide candidates. An in vitro bioassay showed that gem-difluoromethylenated statin analogues have potent effects on JH biosynthesis of M. sexta and high selectivity between H. sapiens and M. sexta. All series II compounds {1,3,5-trisubstituted [4-tert-butyl 2-(5,5-difluoro-2,2-dimethyl-6-vinyl-4-yl) acetate] pyrazoles} have some effect on JH biosynthesis, whereas most of them are inactive on human HMGR. In particular, the IC 50 value of compound II-12 (37.8 nm) is lower than that of lovastatin (99.5 nm) and similar to that of rosuvastatin (24.2 nm). An in vivo bioassay showed that I-1, I-2, I-3 and II-12 are potential selective insecticides, especially for lepidopteran pest control. A predictable and statistically meaningful CoMFA model of 23 inhibitors (20 as training sets and three as test sets) was obtained with a value of q 2 and r 2 of 0.66 and 0.996 respectively. The final model suggested that a potent insect HMGR inhibitor should contain suitable small and non-electronegative groups in the ring part, and electronegative groups in the side chain. Four analogues were discovered as potent selective lepidopteran HMGR inhibitors, which can specifically be used for lepidopteran pest control. The CoMFA model will be useful for the design of new selective insect HMGR inhibitors that are structurally related to the training set compounds. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Production and Characterization of Novel Camel Single Domain Antibody Targeting Mouse Vascular Endothelial Growth Factor.

PubMed

Kazemi-Lomedasht, Fatemeh; Behdani, Mahdi; Habibi-Anbouhi, Mahdi; Shahbazzadeh, Delavar

2016-06-01

Camel single domain antibody known as Nanobody™ refers to a novel class of monoclonal antibodies with appropriate pharmacological properties. Nanobody is an antigen-binding site of camel heavy chain antibody also known as VHH. Expression in a microbial system, stability in difficult conditions and extremes of PH, and nanomolar affinity to target an appropriate drug format makes Nanobody a potential for drug discovery. Needs for Nanobody function evaluation in animal models turned our interest to develop anti-mouse vascular endothelial growth factor (mVEGF) Nanobodies using phage display as a potent technique in the isolation of antibodies. Isolation of anti-mVEGF Nanobodies was performed on Camelus dromedarius immune library through four consecutive rounds of biopanning on immobilized mVEGF. Enrichment of the Nanobody library was monitored by polyclonal phage-ELISA, and specific Nanobodies were selected using periplasmic extract-ELISA. Selected Nanobodies were expressed in WK6 Escherichia coli cells and purified using immobilized metal affinity chromatography. Specificity and affinity of selected Nanobodies were evaluated on immobilized mVEGF. Results demonstrated the successful enrichment of the Nanobody library. Two clones named Nb5 and Nb10 were selected through screening procedures according to their signal value in periplasmic extract-ELISA. Selected Nanobodies specifically reacted to mVEGF, but cross-reactivity with other antigens was not observed. Evaluated affinity for the Nanobodies was in nanomolar range. Taken together, according to the results, the selected Nanobodies promise to be a novel tool in research and for further development of diagnostic or therapeutic purposes in pharmaceutical science.

Tofacitinib and analogs as inhibitors of the histone kinase PRK1 (PKN1).

PubMed

Ostrovskyi, Dmytro; Rumpf, Tobias; Eib, Julia; Lumbroso, Alexandre; Slynko, Inna; Klaeger, Susan; Heinzlmeir, Stephanie; Forster, Michael; Gehringer, Matthias; Pfaffenrot, Ellen; Bauer, Silke Mona; Schmidtkunz, Karin; Wenzler, Sandra; Metzger, Eric; Kuster, Bernhard; Laufer, Stefan; Schüle, Roland; Sippl, Wolfgang; Breit, Bernhard; Jung, Manfred

2016-09-01

The histone kinase PRK1 has been identified as a potential target to combat prostate cancer but selective PRK1 inhibitors are lacking. The US FDA -approved JAK1-3 inhibitor tofacitinib also potently inhibits PRK1 in vitro. We show that tofacitinib also inhibits PRK1 in a cellular setting. Using tofacitinib as a starting point for structure-activity relationship studies, we identified a more potent and another more selective PRK1 inhibitor compared with tofacitinib. Furthermore, we found two potential PRK1/JAK3-selectivity hotspots. The identified inhibitors and the selectivity hotspots lay the basis for the development of selective PRK1 inhibitors. The identification of PRK1, but also of other cellular tofacitinib targets, has implications on its clinical use and on future development of tofacitinib-like JAK inhibitors. [Formula: see text].

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.

Type and location of fluorescent probes incorporated into the potent mu-opioid peptide [Dmt]DALDA affect potency, receptor selectivity and intrinsic efficacy.

PubMed

Schiller, P W; Berezowska, I; Weltrowska, G; Chen, H; Lemieux, C; Chung, N N

2005-06-01

The dermorphin-derived tetrapeptide H-Dmt-d-Arg-Phe-Lys-NH(2) (Dmt = 2',6'-dimethyltyrosine) ([Dmt(1)]DALDA) is a highly potent and selective mu-opioid agonist capable of crossing the blood-brain barrier and producing a potent, centrally mediated analgesic effect when given systemically. For the purpose of biodistribution studies by fluorescence techniques, [Dmt(1)]DALDA analogues containing various fluorescent labels [dansyl, anthraniloyl (atn), fluorescein, or 6-dimethylamino-2'-naphthoyl] in several different locations of the peptide were synthesized and characterized in vitro in the guinea-pig ileum and mouse vas deferens assays, and in mu-, delta- and kappa-opioid receptor-binding assays. The analogues showed various degrees of mu receptor-binding selectivity, but all of them were less mu-selective than the [Dmt(1)]DALDA parent peptide. Most analogues retained potent, full mu-agonist activity, except for one with fluorescein attached at the C-terminus (3a) (partial mu-agonist) and one containing beta-(6'-dimethylamino-2'-naphthoyl)alanine (aladan) in place of Phe(3) (4) (mu- and kappa-antagonist). The obtained data indicate that the receptor-binding affinity, receptor selectivity and intrinsic efficacy of the prepared analogues vary very significantly, depending on the type of fluorescent label used and on its location in the peptide. The results suggest that the biological activity profile of fluorescence-labeled peptide analogues should always be carefully determined prior to their use in biodistribution studies or other studies. One of the analogues containing the atn group (2a) proved highly useful in a study of cellular uptake and intracellular distribution by confocal laser scanning microscopy.

Structure based drug design: development of potent and selective factor IXa (FIXa) inhibitors.

PubMed

Wang, Shouming; Beck, Richard; Burd, Andrew; Blench, Toby; Marlin, Frederic; Ayele, Tenagne; Buxton, Stuart; Dagostin, Claudio; Malic, Maja; Joshi, Rina; Barry, John; Sajad, Mohammed; Cheung, Chiming; Shaikh, Shaheda; Chahwala, Suresh; Chander, Chaman; Baumgartner, Christine; Holthoff, Hans-Peter; Murray, Elizabeth; Blackney, Michael; Giddings, Amanda

2010-02-25

On the basis of our understanding on the binding interactions of the benzothiophene template within the FIXa active site by X-ray crystallography and molecular modeling studies, we developed our SAR strategy by targeting the 4-position of the template to access the S1 beta and S2-S4 sites. A number of highly selective and potent factor Xa (FXa) and FIXa inhibitors were identified by simple switch of functional groups with conformational changes toward the S2-S4 sites.

A selective estrogen receptor modulator for the treatment of hot flushes.

PubMed

Wallace, Owen B; Lauwers, Kenneth S; Dodge, Jeffrey A; May, Scott A; Calvin, Joel R; Hinklin, Ronald; Bryant, Henry U; Shetler, Pamela K; Adrian, Mary D; Geiser, Andrew G; Sato, Masahiko; Burris, Thomas P

2006-02-09

A selective estrogen receptor modulator (SERM) for the potential treatment of hot flushes is described. (R)-(+)-7,9-difluoro-5-[4-(2-piperidin-1-ylethoxy)phenyl]-5H-6-oxachrysen-2-ol, LSN2120310, potently binds ERalpha and ERbeta and is an antagonist in MCF-7 breast adenocarcinoma and Ishikawa uterine cancer cell lines. The compound is a potent estrogen antagonist in the rat uterus. In ovariectomized rats, the compound lowers cholesterol, maintains bone mineral density, and is efficacious in a morphine dependent rat model of hot flush efficacy.

Structural Basis for the Potent and Selective Inhibition of Casein Kinase 1 Epsilon

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

Long, Alexander M.; Zhao, Huilin; Huang, Xin

2012-10-29

Casein kinase 1 epsilon (CK1ε) and its closest homologue CK1δ are key regulators of diverse cellular processes. We report two crystal structures of PF4800567, a potent and selective inhibitor of CK1ε, bound to the kinase domains of human CK1ε and CK1δ as well as one apo CK1ε crystal structure. These structures provide a molecular basis for the strong and specific inhibitor interactions with CK1ε and suggest clues for further development of CK1δ inhibitors.

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

Gentles, Robert G.; Sheriff, Steven; Beno, Brett R.

Structure based rationales for the activities of potent N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamide inhibitors of the hepatitis C viral polymerase are described herein. These compounds bind to the hepatitis C virus non-structural protein 5B (NS5B), and co-crystal structures of select examples from this series with NS5B are reported. Comparison of co-crystal structures of a potent analog with both NS5B genotype 1a and genotype 1b provides a possible explanation for the genotype-selectivity observed with this compound class and suggests opportunities for the further optimization of the series.

Discovery of a Potent BTK Inhibitor with a Novel Binding Mode by Using Parallel Selections with a DNA-Encoded Chemical Library.

PubMed

Cuozzo, John W; Centrella, Paolo A; Gikunju, Diana; Habeshian, Sevan; Hupp, Christopher D; Keefe, Anthony D; Sigel, Eric A; Soutter, Holly H; Thomson, Heather A; Zhang, Ying; Clark, Matthew A

2017-05-04

We have identified and characterized novel potent inhibitors of Bruton's tyrosine kinase (BTK) from a single DNA-encoded library of over 110 million compounds by using multiple parallel selection conditions, including variation in target concentration and addition of known binders to provide competition information. Distinct binding profiles were observed by comparing enrichments of library building block combinations under these conditions; one enriched only at high concentrations of BTK and was competitive with ATP, and another enriched at both high and low concentrations of BTK and was not competitive with ATP. A compound representing the latter profile showed low nanomolar potency in biochemical and cellular BTK assays. Results from kinetic mechanism of action studies were consistent with the selection profiles. Analysis of the co-crystal structure of the most potent compound demonstrated a novel binding mode that revealed a new pocket in BTK. Our results demonstrate that profile-based selection strategies using DNA-encoded libraries form the basis of a new methodology to rapidly identify small molecule inhibitors with novel binding modes to clinically relevant targets. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Potent, Selective SRPK1 Inhibitors as Potential Topical Therapeutics for Neovascular Eye Disease.

PubMed

Batson, Jennifer; Toop, Hamish D; Redondo, Clara; Babaei-Jadidi, Roya; Chaikuad, Apirat; Wearmouth, Stephen F; Gibbons, Brian; Allen, Claire; Tallant, Cynthia; Zhang, Jingxue; Du, Chunyun; Hancox, Jules C; Hawtrey, Tom; Da Rocha, Joana; Griffith, Renate; Knapp, Stefan; Bates, David O; Morris, Jonathan C

2017-03-17

Serine/arginine-protein kinase 1 (SRPK1) regulates alternative splicing of VEGF-A to pro-angiogenic isoforms and SRPK1 inhibition can restore the balance of pro/antiangiogenic isoforms to normal physiological levels. The lack of potency and selectivity of available compounds has limited development of SRPK1 inhibitors, with the control of alternative splicing by splicing factor-specific kinases yet to be translated. We present here compounds that occupy a binding pocket created by the unique helical insert of SRPK1, and trigger a backbone flip in the hinge region, that results in potent (<10 nM) and selective inhibition of SRPK1 kinase activity. Treatment with these inhibitors inhibited SRPK1 activity and phosphorylation of serine/arginine splicing factor 1 (SRSF1), resulting in alternative splicing of VEGF-A from pro-angiogenic to antiangiogenic isoforms. This property resulted in potent inhibition of blood vessel growth in models of choroidal angiogenesis in vivo. This work identifies tool compounds for splice isoform selective targeting of pro-angiogenic VEGF, which may lead to new therapeutic strategies for a diversity of diseases where dysfunctional splicing drives disease development.

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.

Synthesis and biological evaluation of di-aryl urea derivatives as c-Kit inhibitors.

PubMed

Ravez, Séverine; Arsenlis, Stéphane; Barczyk, Amélie; Dupont, Anthony; Frédérick, Raphaël; Hesse, Stéphanie; Kirsch, Gilbert; Depreux, Patrick; Goossens, Laurence

2015-11-15

Inhibition of receptor tyrosine kinases (RTKs) continued to be a successful approach for the treatment of many types of human cancers and many potent small molecules kinase inhibitors have been discovered the last decade. In the present study, we describe the synthesis of thienopyrimidine derivatives and their pharmacological evaluation against nine kinases (EGFR, PDGFR-ß, c-Kit, c-Met, Src, Raf, VEGFR-1, -2 and -3). Most of the synthesized compounds showed from moderate to potent activities against c-Kit with IC50 values in the nanomolar range. Among them, 4-anilino(urea)thienopyrimidine analogs showed selectivity and potent c-Kit inhibition with IC50 values less than 6 nM. Docking simulation was performed for the most promising compound 9 into the c-Kit active site to determine the potential binding mode. This study reveal that the 4-anilino(urea)thienopyrimidine is an interesting scaffold to design novel potent and selective c-Kit inhibitors which may make promising candidates for cancers where c-Kit receptors are overexpressed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and characterization of potent and selective mu-opioid receptor antagonists, [Dmt(1), D-2-Nal(4)]endomorphin-1 (Antanal-1) and [Dmt(1), D-2-Nal(4)]endomorphin-2 (Antanal-2).

PubMed

Fichna, Jakub; do-Rego, Jean-Claude; Chung, Nga N; Lemieux, Carole; Schiller, Peter W; Poels, Jeroen; Broeck, Jozef Vanden; Costentin, Jean; Janecka, Anna

2007-02-08

To synthesize potent antagonists of the mu-opioid receptor, we prepared a series of endomorphin-1 and endomorphin-2 analogues with 3-(1-naphthyl)-d-alanine (d-1-Nal) or 3-(2-naphthyl)-d-alanine (d-2-Nal) in position 4. Some of these analogues displayed weak antagonist properties. We tried to strengthen these properties by introducing the structurally modified tyrosine residue 2,6-dimethyltyrosine (Dmt) in place of Tyr1. Among the synthesized compounds, [Dmt1, d-2-Nal4]endomorphin-1, designated antanal-1, and [Dmt1, d-2-Nal4]endomorphin-2, designated antanal-2, turned out to be highly potent and selective mu-opioid receptor antagonists, as judged on the basis of two functional assays, the receptor binding assay and the hot plate test of analgesia. Interestingly, another analogue of this series, [Dmt1, d-1-Nal4]endomorphin-1, turned out to be a moderately potent mixed mu-agonist/delta-antagonist.

(3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone: A potent, selective, orally active dipeptidyl peptidase IV inhibitor

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

Ammirati, Mark J.; Andrews, Kim M.; Boyer, David D.

2010-10-01

A series of 4-substituted proline amides was synthesized and evaluated as inhibitors of dipeptidyl pepdidase IV for the treatment of type 2 diabetes. (3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone (5) emerged as a potent (IC{sub 50} = 13 nM) and selective compound, with high oral bioavailability in preclinical species and low plasma protein binding. Compound 5, PF-00734200, was selected for development as a potential new treatment for type 2 diabetes.

Toxic potential of palytoxin.

PubMed

Patocka, Jiří; Gupta, Ramesh C; Wu, Qing-hua; Kuca, Kamil

2015-10-01

This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.

Synthesis of Degradable Poly(vinyl alcohol) by Radical Ring-Opening Copolymerization and Ice Recrystallization Inhibition Activity.

PubMed

Hedir, Guillaume; Stubbs, Christopher; Aston, Phillip; Dove, Andrew P; Gibson, Matthew I

2017-12-19

Poly(vinyl alcohol) (PVA) is the most active synthetic mimic of antifreeze proteins and has extremely high ice recrystallization inhibition (IRI) activity. Addition of PVA to cellular cryopreservation solutions increases the number of recovered viable cells due to its potent IRI, but it is intrinsically nondegradable in vivo . Here we report the synthesis, characterization, and IRI activity of PVA containing degradable ester linkages. Vinyl chloroacetate (VClAc) was copolymerized with 2-methylene-1,3-dioxepane (MDO) which undergoes radical ring-opening polymerization to install main-chain ester units. The use of the chloroacetate monomer enabled selective deacetylation with retention of esters within the polymer backbone. Quantitative IRI assays revealed that the MDO content had to be finely tuned to retain IRI activity, with higher loadings (24 mol %) resulting in complete loss of IRI activity. These degradable materials will help translate PVA, which is nontoxic and biocompatible, into a range of biomedical applications.

Targeting Type 2 Diabetes with C-Glucosyl Dihydrochalcones as Selective Sodium Glucose Co-Transporter 2 (SGLT2) Inhibitors: Synthesis and Biological Evaluation.

PubMed

Jesus, Ana R; Vila-Viçosa, Diogo; Machuqueiro, Miguel; Marques, Ana P; Dore, Timothy M; Rauter, Amélia P

2017-01-26

Inhibiting glucose reabsorption by sodium glucose co-transporter proteins (SGLTs) in the kidneys is a relatively new strategy for treating type 2 diabetes. Selective inhibition of SGLT2 over SGLT1 is critical for minimizing adverse side effects associated with SGLT1 inhibition. A library of C-glucosyl dihydrochalcones and their dihydrochalcone and chalcone precursors was synthesized and tested as SGLT1/SGLT2 inhibitors using a cell-based fluorescence assay of glucose uptake. The most potent inhibitors of SGLT2 (IC 50 = 9-23 nM) were considerably weaker inhibitors of SGLT1 (IC 50 = 10-19 μM). They showed no effect on the sodium independent GLUT family of glucose transporters, and the most potent ones were not acutely toxic to cultured cells. The interaction of a C-glucosyl dihydrochalcone with a POPC membrane was modeled computationally, providing evidence that it is not a pan-assay interference compound. These results point toward the discovery of structures that are potent and highly selective inhibitors of SGLT2.

Synthesis and pharmacological characterization of novel xanthine carboxylate amides as A2A adenosine receptor ligands exhibiting bronchospasmolytic activity.

PubMed

Yadav, Rakesh; Bansal, Ranju; Rohilla, Suman; Kachler, Sonja; Klotz, Karl-Norbert

2016-04-01

The carboxylate amides of 8-phenyl-1,3-dimethylxanthine described herein represent a new series of selective ligands of the adenosine A2A receptors exhibiting bronchospasmolytic activity. The effects of location of 8-phenyl substitutions on the adenosine receptor (AR) binding affinities of the newly synthesized xanthines have also been studied. The compounds displayed moderate to potent binding affinities toward various adenosine receptor subtypes when evaluated through radioligand binding studies. However, most of the compounds showed the maximum affinity for the A2A subtype, some with high selectivity versus all other subtypes. Xanthine carboxylate amide 13b with a diethylaminoethylamino moiety at the para-position of the 8-phenylxanthine scaffold was identified as the most potent A2A adenosine receptor ligand with Ki=0.06μM. Similarly potent and highly A2A-selective are the isovanillin derivatives 16a and 16d. In addition, the newly synthesized xanthine derivatives showed good in vivo bronchospasmolytic activity when tested in guinea pigs. Copyright © 2016 Elsevier Inc. All rights reserved.

Structure guided design of potent and selective ponatinib-based hybrid inhibitors for RIPK1

PubMed Central

Najjar, Malek; Suebsuwong, Chalada; Ray, Soumya S.; Thapa, Roshan J.; Maki, Jenny L.; Nogusa, Shoko; Shah, Saumil; Saleh, Danish; Gough, Peter J.; Bertin, John; Yuan, Junying; Balachandran, Siddharth; Cuny, Gregory D.; Degterev, Alexei

2015-01-01

Summary RIPK1 and RIPK3, two closely related RIPK family members, have emerged as important regulators of pathologic cell death and inflammation. In the current work, we report that the Bcr-Abl inhibitor and anti-leukemia agent ponatinib is also a first-in-class dual inhibitor of RIPK1 and RIPK3. Ponatinib potently inhibited multiple paradigms of RIPK1- and RIPK3-dependent cell death and inflammatory TNFα gene transcription. We further describe design strategies that utilize the ponatinib scaffold to develop two classes of inhibitors (CS and PN series), each with greatly improved selectivity for RIPK1. In particular, we detail the development of PN10, a highly potent and selective ‘hybrid’ RIPK1 inhibitor, capturing the best properties of two different allosteric RIPK1 inhibitors, ponatinib and necrostatin-1. Finally, we show that RIPK1 inhibitors from both classes are powerful blockers of TNF-induced injury in vivo. Altogether, these findings outline promising candidate molecules and design approaches for targeting RIPK1/3-driven inflammatory pathologies. PMID:25801024

O-Phenyl Carbamate and Phenyl Urea Thiiranes as Selective Matrix Metalloproteinase-2 Inhibitors that Cross the Blood-Brain Barrier

PubMed Central

Gooyit, Major; Song, Wei; Mahasenan, Kiran V.; Lichtenwalter, Katerina; Suckow, Mark A.; Schroeder, Valerie A.; Wolter, William R.; Mobashery, Shahriar; Chang, Mayland

2013-01-01

Brain metastasis occurs in 20% to 40% of cancer patients. Treatment is mostly palliative and the inability of most drugs to penetrate the brain presents one of the greatest challenges in the development of therapeutics for brain metastasis. Matrix metalloproteinase-2 (MMP-2) plays important roles in invasion and vascularization of the central nervous system and represents a potential target for treatment of brain metastasis. Carbonate, O-phenyl carbamate, urea, and N-phenyl carbamate derivatives of SB-3CT, a selective and potent gelatinase inhibitor were synthesized and evaluated. The O-phenyl carbamate and urea variants were selective and potent inhibitors of MMP-2. Carbamate 5b was metabolized to the potent gelatinase inhibitor 2, which was present at therapeutic concentrations in the brain. In contrast, phenyl urea 6b crossed the blood-brain barrier, however higher doses would result in therapeutic brain concentrations. Carbamate 5b and urea 6b show potential for intervention of MMP-2-dependent diseases, such as brain metastasis. PMID:24028490

Elevation of cellular O-GlcNAcylation level by a potent and selective O-GlcNAcase inhibitor based on tetrahydroimidazopyridine scaffold.

PubMed

Li, Tiehai; Li, Zhonghua; Li, Jing; Wang, Jiajia; Guo, Lina; Wang, Peng George; Zhao, Wei

2012-11-15

Protein O-GlcNAc glycosylation is a ubiquitous post-translational modification in metazoans. O-GlcNAcase (OGA), which is responsible for removing O-GlcNAc from serine or threonine residues, plays a key role in O-GlcNAc metabolism. Potent and selective O-GlcNAcase (OGA) inhibitors are useful tools for investigating the role of this modification in a broad range of cellular processes, and may also serve as drug candidates for treatment of neurodegenerative diseases. Biological screening of the gluco-configured tetrahydroimidazopyridine derivatives identified a compound as a potent and competitive inhibitor of human O-GlcNAcase (OGA) with a K(i) of 5.9 μM, and it also displayed 28-fold selectivity for human OGA over human lysosomal β-hexosaminidase A (Hex A, K(i)=163 μM). In addition, cell-based assay revealed that this compound was cell-permeant and effectively induced cellular hyper-O-GlcNAcylation at 10 μM concentration. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

A Potent and Site-Selective Agonist of TRPA1.

PubMed

Takaya, Junichiro; Mio, Kazuhiro; Shiraishi, Takuya; Kurokawa, Tatsuki; Otsuka, Shinya; Mori, Yasuo; Uesugi, Motonari

2015-12-23

TRPA1 is a member of the transient receptor potential (TRP) cation channel family that is expressed primarily on sensory neurons. This chemosensor is activated through covalent modification of multiple cysteine residues with a wide range of reactive compounds including allyl isothiocyanate (AITC), a spicy component of wasabi. The present study reports on potent and selective agonists of TRPA1, discovered through screening 1657 electrophilic molecules. In an effort to validate the mode of action of hit molecules, we noted a new TRPA1-selective agonist, JT010 (molecule 1), which opens the TRPA1 channel by covalently and site-selectively binding to Cys621 (EC50 = 0.65 nM). The results suggest that a single modification of Cys621 is sufficient to open the TRPA1 channel. The TRPA1-selective probe described herein might be useful for further mechanistic studies of TRPA1 activation.

N-Guanidino Derivatives of 1,5-Dideoxy-1,5-imino-d-xylitol are Potent, Selective, and Stable Inhibitors of β-Glucocerebrosidase.

PubMed

Sevšek, Alen; Šrot, Luka; Rihter, Jakob; Čelan, Maša; van Ufford, Linda Quarles; Moret, Ed E; Martin, Nathaniel I; Pieters, Roland J

2017-04-06

A series of lipidated guanidino and urea derivatives of 1,5-dideoxy-1,5-imino-d-xylitol were prepared from d-xylose using a concise synthetic protocol. Inhibition assays with a panel of glycosidases revealed that the guanidino analogues display potent inhibition against human recombinant β-glucocerebrosidase with IC 50 values in the low nanomolar range. Related urea analogues of 1,5-dideoxy-1,5-imino-d-xylitol were also synthesized and evaluated in the same fashion and found to be selective for β-galactosidase from bovine liver. No inhibition of human recombinant β-glucocerebrosidase was observed for the urea analogues. Computational studies provided insight into the potent activity of analogues bearing the substituted guanidine moiety in the inhibition of lysosomal glucocerebrosidase (GBA). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Next generation semiconductor based-sequencing of a nutrigenetics target gene (GPR120) and association with growth rate in Italian Large White pigs.

PubMed

Fontanesi, Luca; Bertolini, Francesca; Scotti, Emilio; Schiavo, Giuseppina; Colombo, Michela; Trevisi, Paolo; Ribani, Anisa; Buttazzoni, Luca; Russo, Vincenzo; Dall'Olio, Stefania

2015-01-01

The GPR120 gene (also known as FFAR4 or O3FAR1) encodes for a functional omega-3 fatty acid receptor/sensor that mediates potent insulin sensitizing effects by repressing macrophage-induced tissue inflammation. For its functional role, GPR120 could be considered a potential target gene in animal nutrigenetics. In this work we resequenced the porcine GPR120 gene by high throughput Ion Torrent semiconductor sequencing of amplified fragments obtained from 8 DNA pools derived, on the whole, from 153 pigs of different breeds/populations (two Italian Large White pools, Italian Duroc, Italian Landrace, Casertana, Pietrain, Meishan, and wild boars). Three single nucleotide polymorphisms (SNPs), two synonymous substitutions and one in the putative 3'-untranslated region (g.114765469C > T), were identified and their allele frequencies were estimated by sequencing reads count. The g.114765469C > T SNP was also genotyped by PCR-RFLP confirming estimated frequency in Italian Large White pools. Then, this SNP was analyzed in two Italian Large White cohorts using a selective genotyping approach based on extreme and divergent pigs for back fat thickness (BFT) estimated breeding value (EBV) and average daily gain (ADG) EBV. Significant differences of allele and genotype frequencies distribution was observed between the extreme ADG-EBV groups (P < 0.001) whereas this marker was not associated with BFT-EBV.

6'-Guanidinonaltrindole (6'-GNTI) is a G protein-biased κ-opioid receptor agonist that inhibits arrestin recruitment.

PubMed

Rives, Marie-Laure; Rossillo, Mary; Liu-Chen, Lee-Yuan; Javitch, Jonathan A

2012-08-03

κ-Opioid receptor (KOR) agonists do not activate the reward pathway stimulated by morphine-like μ-opioid receptor (MOR) agonists and thus have been considered to be promising nonaddictive analgesics. However, KOR agonists produce other adverse effects, including dysphoria, diuresis, and constipation. The therapeutic promise of KOR agonists has nonetheless recently been revived by studies showing that their dysphoric effects require arrestin recruitment, whereas their analgesic effects do not. Moreover, KOR agonist-induced antinociceptive tolerance observed in vivo has also been proposed to be correlated to the ability to induce arrestin-dependent phosphorylation, desensitization, and internalization of the receptor. The discovery of functionally selective drugs that are therapeutically effective without the adverse effects triggered by the arrestin pathway is thus an important goal. We have identified such an extreme G protein-biased KOR compound, 6'-guanidinonaltrindole (6'-GNTI), a potent partial agonist at the KOR receptor for the G protein activation pathway that does not recruit arrestin. Indeed, 6'-GNTI functions as an antagonist to block the arrestin recruitment and KOR internalization induced by other nonbiased agonists. As an extremely G protein-biased KOR agonist, 6'-GNTI represents a promising lead compound in the search for nonaddictive opioid analgesic as its signaling profile suggests that it will be without the dysphoria and other adverse effects promoted by arrestin recruitment and its downstream signaling.

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.

Identification of [4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)-2-pyrimidinyl] amines and ethers as potent and selective cyclooxygenase-2 inhibitors.

PubMed

Swarbrick, Martin E; Beswick, Paul J; Gleave, Robert J; Green, Richard H; Bingham, Sharon; Bountra, Chas; Carter, Malcolm C; Chambers, Laura J; Chessell, Iain P; Clayton, Nick M; Collins, Sue D; Corfield, John A; Hartley, C David; Kleanthous, Savvas; Lambeth, Paul F; Lucas, Fiona S; Mathews, Neil; Naylor, Alan; Page, Lee W; Payne, Jeremy J; Pegg, Neil A; Price, Helen S; Skidmore, John; Stevens, Alexander J; Stocker, Richard; Stratton, Sharon C; Stuart, Alastair J; Wiseman, Joanne O

2009-08-01

A novel series of [4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)-2-pyrimidine-based cyclooxygenase-2 (COX-2) inhibitors, which have a different arrangement of substituents compared to the more common 1,2-diarylheterocycle based molecules, have been discovered. For example, 2-(butyloxy)-4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)pyrimidine (47), a member of the 2-pyrimidinyl ether series, has been shown to be a potent and selective inhibitor with a favourable pharmacokinetic profile, high brain penetration and good efficacy in rat models of hypersensitivity.

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.

Potent antitumor activity of a urokinase-activated engineered anthrax toxin

NASA Astrophysics Data System (ADS)

Liu, Shihui; Aaronson, Hannah; Mitola, David J.; Leppla, Stephen H.; Bugge, Thomas H.

2003-01-01

The acquisition of cell-surface urokinase plasminogen activator activity is a hallmark of malignancy. We generated an engineered anthrax toxin that is activated by cell-surface urokinase in vivo and displays limited toxicity to normal tissue but broad and potent tumoricidal activity. Native anthrax toxin protective antigen, when administered with a chimeric anthrax toxin lethal factor, Pseudomonas exotoxin fusion protein, was extremely toxic to mice, causing rapid and fatal organ damage. Replacing the furin activation sequence in anthrax toxin protective antigen with an artificial peptide sequence efficiently activated by urokinase greatly attenuated toxicity to mice. In addition, the mutation conferred cell-surface urokinase-dependent toxin activation in vivo, as determined by using a panel of plasminogen, plasminogen activator, plasminogen activator receptor, and plasminogen activator inhibitor-deficient mice. Surprisingly, toxin activation critically depended on both urokinase plasminogen activator receptor and plasminogen in vivo, showing that both proteins are essential cofactors for the generation of cell-surface urokinase. The engineered toxin displayed potent tumor cell cytotoxicity to a spectrum of transplanted tumors of diverse origin and could eradicate established solid tumors. This tumoricidal activity depended strictly on tumor cell-surface plasminogen activation. The data show that a simple change of protease activation specificity converts anthrax toxin from a highly lethal to a potent tumoricidal agent.

Substituted 7-amino-5-thio-thiazolo[4,5-d]pyrimidines as potent and selective antagonists of the fractalkine receptor (CX3CR1).

PubMed

Karlström, Sofia; Nordvall, Gunnar; Sohn, Daniel; Hettman, Andreas; Turek, Dominika; Åhlin, Kristofer; Kers, Annika; Claesson, Martina; Slivo, Can; Lo-Alfredsson, Yvonne; Petersson, Carl; Bessidskaia, Galina; Svensson, Per H; Rein, Tobias; Jerning, Eva; Malmberg, Åsa; Ahlgen, Charlotte; Ray, Colin; Vares, Lauri; Ivanov, Vladimir; Johansson, Rolf

2013-04-25

We have developed two parallel series, A and B, of CX3CR1 antagonists for the treatment of multiple sclerosis. By modifying the substituents on the 7-amino-5-thio-thiazolo[4,5-d]pyrimidine core structure, we were able to achieve compounds with high selectivity for CX3CR1 over the closely related CXCR2 receptor. The structure-activity relationships showed that a leucinol moiety attached to the core-structure in the 7-position together with α-methyl branched benzyl derivatives in the 5-position displayed promising affinity, and selectivity as well as physicochemical properties, as exemplified by compounds 18a and 24h. We show the preparation of the first potent and selective orally available CX3CR1 antagonists.

Potent, selective, orally bioavailable inhibitors of tumor necrosis factor-alpha converting enzyme (TACE): discovery of indole, benzofuran, imidazopyridine and pyrazolopyridine P1' substituents.

PubMed

Lu, Zhonghui; Ott, Gregory R; Anand, Rajan; Liu, Rui-Qin; Covington, Maryanne B; Vaddi, Krishna; Qian, Mingxin; Newton, Robert C; Christ, David D; Trzaskos, James; Duan, James J-W

2008-03-15

Potent and selective inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered with several new heterocyclic P1' groups in conjunction with cyclic beta-amino hydroxamic acid scaffolds. Among them, the pyrazolopyridine provided the best overall profile when combined with tetrahydropyran beta-amino hydroxamic acid scaffold. Specifically, inhibitor 49 showed IC(50) value of 1 nM against porcine TACE and 170 nM in the suppression of LPS-induced TNF-alpha of human whole blood. Compound 49 also displayed excellent selectivity over a wide panel of MMPs as well as excellent oral bioavailability (F%>90%) in rat n-in-1 PK studies.

Novel arylalkenylpropargylamines as neuroprotective, potent, and selective monoamine oxidase B inhibitors for the treatment of Parkinson's disease.

PubMed

Huleatt, Paul B; Khoo, Mui Ling; Chua, Yi Yuan; Tan, Tiong Wei; Liew, Rou Shen; Balogh, Balázs; Deme, Ruth; Gölöncsér, Flóra; Magyar, Kalman; Sheela, David P; Ho, Han Kiat; Sperlágh, Beáta; Mátyus, Péter; Chai, Christina L L

2015-02-12

To develop novel neuroprotective agents, a library of novel arylalkenylpropargylamines was synthesized and tested for inhibitory activities against monoamine oxidases. From this, a number of highly potent and selective monoamine oxidase B inhibitors were identified. Selected compounds were also tested for neuroprotection in in vitro studies with PC-12 cells treated with 6-OHDA and rotenone, respectively. It was observed that some of the compounds tested yielded a marked increase in survival in PC-12 cells treated with the neurotoxins. This indicates that these propargylamines are able to confer protection against the effects of the toxins and may also be considered as novel disease-modifying anti-Parkinsonian agents, which are much needed for the therapy of Parkinson's disease.

Design and Discovery of N -(2-Methyl-5'-morpholino-6'-((tetrahydro-2 H -pyran-4-yl)oxy)-[3,3'-bipyridin]-5-yl)-3-(trifluoromethyl)benzamide (RAF709): A Potent, Selective, and Efficacious RAF Inhibitor Targeting RAS Mutant Cancers

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

Nishiguchi, Gisele A.; Rico, Alice; Tanner, Huw

RAS oncogenes have been implicated in >30% of human cancers, all representing high unmet medical need. The exquisite dependency on CRAF kinase in KRAS mutant tumors has been established in genetically engineered mouse models and human tumor cells. To date, many small molecule approaches are under investigation to target CRAF, yet kinase-selective and cellular potent inhibitors remain challenging to identify. Herein, we describe 14 (RAF709) [Aversa, Biaryl amide compounds as kinase inhibitors and their preparation. WO 2014151616, 2014], a selective B/C RAF inhibitor, which was developed through a hypothesis-driven approach focusing on drug-like properties. A key challenge encountered in themore » medicinal chemistry campaign was maintaining a balance between good solubility and potent cellular activity (suppression of pMEK and proliferation) in KRAS mutant tumor cell lines. We investigated the small molecule crystal structure of lead molecule 7 and hypothesized that disruption of the crystal packing would improve solubility, which led to a change from N-methylpyridone to a tetrahydropyranyl oxy-pyridine derivative. 14 proved to be soluble, kinase selective, and efficacious in a KRAS mutant xenograft model.« less

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

Selecting climate change scenarios for regional hydrologic impact studies based on climate extremes indices

NASA Astrophysics Data System (ADS)

Seo, Seung Beom; Kim, Young-Oh; Kim, Youngil; Eum, Hyung-Il

2018-04-01

When selecting a subset of climate change scenarios (GCM models), the priority is to ensure that the subset reflects the comprehensive range of possible model results for all variables concerned. Though many studies have attempted to improve the scenario selection, there is a lack of studies that discuss methods to ensure that the results from a subset of climate models contain the same range of uncertainty in hydrologic variables as when all models are considered. We applied the Katsavounidis-Kuo-Zhang (KKZ) algorithm to select a subset of climate change scenarios and demonstrated its ability to reduce the number of GCM models in an ensemble, while the ranges of multiple climate extremes indices were preserved. First, we analyzed the role of 27 ETCCDI climate extremes indices for scenario selection and selected the representative climate extreme indices. Before the selection of a subset, we excluded a few deficient GCM models that could not represent the observed climate regime. Subsequently, we discovered that a subset of GCM models selected by the KKZ algorithm with the representative climate extreme indices could not capture the full potential range of changes in hydrologic extremes (e.g., 3-day peak flow and 7-day low flow) in some regional case studies. However, the application of the KKZ algorithm with a different set of climate indices, which are correlated to the hydrologic extremes, enabled the overcoming of this limitation. Key climate indices, dependent on the hydrologic extremes to be projected, must therefore be determined prior to the selection of a subset of GCM models.

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.

D-piece modifications of the hemiasterlin analog HTI-286 produce potent tubulin inhibitors.

PubMed

Zask, Arie; Birnberg, Gary; Cheung, Katherine; Kaplan, Joshua; Niu, Chuan; Norton, Emily; Yamashita, Ayako; Beyer, Carl; Krishnamurthy, Girija; Greenberger, Lee M; Loganzo, Frank; Ayral-Kaloustian, Semiramis

2004-08-16

Modifications of the D-piece carboxylic acid group of the hemiasterlin analog HTI-286 gave tubulin inhibitors which were potent cytotoxic agents in taxol resistant cell lines expressing P-glycoprotein. Amides derived from proline had potency comparable to HTI-286. Reduction of the carboxylic acid to ketones and alcohols or its conversion to acidic heterocycles also gave potent analogs. Synthetic modifications of the carboxylic acid could be carried out selectively using a wide range of synthetic reagents. Proline analog 3 was found to be effective in a human xenograft model in athymic mice.

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

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.

Structure-activity relationships of phenothiazines and related drugs for inhibition of protein kinase C.

PubMed

Aftab, D T; Ballas, L M; Loomis, C R; Hait, W N

1991-11-01

Phenothiazines are known to inhibit the activity of protein kinase C. To identify structural features that determine inhibitory activity against the enzyme, we utilized a semiautomated assay [Anal. Biochem. 187:84-88 (1990)] to compare the potency of greater than 50 phenothiazines and related compounds. Potency was decreased by trifluoro substitution at position 2 on the phenothiazine nucleus and increased by quinoid structures on the nucleus. An alkyl bridge of at least three carbons connecting the terminal amine to the nucleus was required for activity. Primary amines and unsubstituted piperazines were the most potent amino side chains. We selected 7,8-dihydroxychlorpromazine (DHCP) (IC50 = 8.3 microM) and 2-chloro-9-(3-[1-piperazinyl]propylidene)thioxanthene (N751) (IC50 = 14 microM) for further study because of their potency and distinct structural features. Under standard (vesicle) assay conditions, DHCP was noncompetitive with respect to phosphatidylserine and a mixed-type inhibitor with respect to ATP. N751 was competitive with respect to phosphatidylserine and noncompetitive with respect to ATP. Using the mixed micelle assay, DHCP was a competitive inhibitor with respect to both phosphatidylserine and ATP. DHCP was selective for protein kinase C compared with cAMP-dependent protein kinase, calmodulin-dependent protein kinase type II, and casein kinase. N751 was more potent against protein kinase C compared with cAMP-dependent protein kinase and casein kinase but less potent against protein kinase C compared with calmodulin-dependent protein kinase type II. DHCP was analyzed for its ability to inhibit different isoenzymes of protein kinase C, and no significant isozyme selectivity was detected. These data provide important information for the rational design of more potent and selective inhibitors of protein kinase C.

Synthesis and evaluation of 2-benzylidene-1-tetralone derivatives for monoamine oxidase inhibitory activity.

PubMed

Amakali, Klaudia T; Legoabe, Lesetja Jan; Petzer, Anel; Petzer, Jacobus P

2018-05-01

Chalcone has been identified as a promising lead for the design of monoamine oxidase (MAO) inhibitors. This study attempted to discover potent and selective chalcone-derived MAO inhibitors by synthesising a series consisting of various cyclic chalcone derivatives. The cyclic chalcones were selected based on the possibility that their restricted structures would confer a higher degree of MAO isoform selectivity, and included the following chemical classes: 1-indanone, 1-tetralone, 1-benzosuberone, chromone, thiochromone, 4-chromanone and 4-thiochromanone. The results showed that the cyclic chalcones are in general good potency, and in most instances specific inhibitors of the human MAO-B isoform. Among these compounds, the 4-chromanone derivative was the most potent MAO-B inhibitor with an IC50 value of 0.156 µM. To further investigate the MAO inhibition of cyclic chalcones, a series of twenty-three 2-benzylidene-1-tetralone derivatives were synthesised and evaluated as MAO inhibitors. Most 2-benzylidene-1-tetralones possess good inhibitory activity and specificity for MAO-B with the most potent inhibitor displaying an IC50 value of 0.0064 µM, while the most potent MAO-A inhibitor possessed an IC50 value of 0.754 µM. This study thus shows that certain cyclic chalcones are human MAO-B inhibitors, compounds that could be suitable for the treatment of neurodegenerative disorders such as Parkinson's disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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

Relative potency of varenicline or fluvoxamine to reduce responding for ethanol versus food depends on the presence or absence of concurrently earned food.

PubMed

Ginsburg, Brett C; Lamb, Richard J

2014-03-01

Varenicline, a nicotinic partial agonist, selectively reduces ethanol (EtOH)- versus sucrose-maintained behavior when tested in separate groups, yet like the indirect agonist fluvoxamine, this selectively inverts when EtOH and food are concurrently available. Here, we extend these findings by examining varenicline and fluvoxamine effects under a multiple concurrent schedule where food and EtOH are concurrently available in different components: Component 1 where the food fixed-ratio was 25 and Component 2 where the food fixed-ratio was 75. The EtOH fixed-ratio was always 5. Food-maintained responding predominated in Component 1, while EtOH-maintained responding predominated in Component 2. In a second experiment, varenicline effects were assessed under a multiple schedule where food, then EtOH, then again food were available in separate 5-minute components with fixed-ratios of 5 for each reinforcement. In the multiple concurrent schedule, varenicline was more potent at reducing food- versus EtOH-maintained responding in both components and reduced EtOH-maintained responding more potently during Component 1 (when food was almost never earned) than in Component 2 (where food was often earned). Fluvoxamine was similarly potent at reducing food- and EtOH-maintained responding. Under the multiple schedule, varenicline, like fluvoxamine, more potently decreases EtOH- versus food maintained responding when only food or EtOH is available in separate components. These results demonstrate that selective effects on drug- versus alternative-maintained behavior depend on the schedule arrangement, and assays in which EtOH or an alternative is the only programmed reinforcement may overestimate the selectivity of treatments to decrease EtOH self-administration. Thus selective effects obtained under one assay may not generalize to another. Better understanding the behavioral mechanisms responsible for these results may help to guide pharmaco-therapeutic development for substance use disorders.

The Design and Development of a Potent and Selective Novel Diprolyl Derivative That Binds to the N-Domain of Angiotensin-I Converting Enzyme.

PubMed

Fienberg, Stephen; Cozier, Gyles E; Acharya, K Ravi; Chibale, Kelly; Sturrock, Edward D

2018-01-11

Angiotensin-I converting enzyme (ACE) is a zinc metalloprotease consisting of two catalytic domains (N- and C-). Most clinical ACE inhibitor(s) (ACEi) have been shown to inhibit both domains nonselectively, resulting in adverse effects such as cough and angioedema. Selectively inhibiting the individual domains is likely to reduce these effects and potentially treat fibrosis in addition to hypertension. ACEi from the GVK Biosciences database were inspected for possible N-domain selective binding patterns. From this set, a diprolyl chemical series was modeled using docking simulations. The series was expanded based on key target interactions involving residues known to impart N-domain selectivity. In total, seven diprolyl compounds were synthesized and tested for N-domain selective ACE inhibition. One compound with an aspartic acid in the P 2 position (compound 16) displayed potent inhibition (K i = 11.45 nM) and was 84-fold more selective toward the N-domain. A high-resolution crystal structure of compound 16 in complex with the N-domain revealed the molecular basis for the observed selectivity.

Selection of new more potent strains of Bacillus thuringiensis for use against gypsy moth and spruce budworm

Treesearch

Normand R. Dubois

1985-01-01

The increased use of B. thuringiensis as an alternative to chemical insecticides has stimulated the search for more potent strains. Presently over 1100 strains have been isolated from worldwide sources. Some of these appear to be more effective than the commercially developed HD-1 strain against both the gypsy moth and spruce budworm. One strain in...

Synthesis of the PPARbeta/delta-selective agonist GW501516 and C4-thiazole-substituted analogs.

PubMed

Pereira, Raquel; Gaudon, Claudine; Iglesias, Beatriz; Germain, Pierre; Gronemeyer, Hinrich; de Lera, Angel R

2006-01-01

Sequential, position-selective, Pd-catalyzed cross-coupling reactions of 2,4-dibromo-5-hydroxymethylthiazole provided the scaffold for the synthesis of GW501516, the most potent PPARbeta/delta agonist yet described, and equally selective analogs at the thiazole-C4 position.

Signal transduction and functional selectivity of F15599, a preferential post-synaptic 5-HT1A receptor agonist

PubMed Central

Newman-Tancredi, A; Martel, J-C; Assié, M-B; Buritova, J; Lauressergues, E; Cosi, C; Heusler, P; Slot, L Bruins; Colpaert, FC; Vacher, B; Cussac, D

2009-01-01

Background and purpose: Activation of post-synaptic 5-HT1A receptors may provide enhanced therapy against depression. We describe the signal transduction profile of F15599, a novel 5-HT1A receptor agonist. Experimental approach: F15599 was compared with a chemical congener, F13714, and with (+)8-OH-DPAT in models of signal transduction in vitro and ex vivo. Key results: F15599 was highly selective for 5-HT1A receptors in binding experiments and in [35S]-GTPγS autoradiography of rat brain, where F15599 increased labelling in regions expressing 5-HT1A receptors. In cell lines expressing h5-HT1A receptors, F15599 more potently stimulated extracellular signal-regulated kinase (ERK1/2) phosphorylation, compared with G-protein activation, internalization of h5-HT1A receptors or inhibition of cAMP accumulation. F13714, (+)8-OH-DPAT and 5-HT displayed a different rank order of potency for these responses. F15599 stimulated [35S]-GTPγS binding more potently in frontal cortex than raphe. F15599, unlike 5-HT, more potently and efficaciously stimulated Gαi than Gαo activation. In rat prefrontal cortex (a region expressing post-synaptic 5-HT1A receptors), F15599 potently activated ERK1/2 phosphorylation and strongly induced c-fos mRNA expression. In contrast, in raphe regions (expressing pre-synaptic 5-HT1A receptors) F15599 only weakly or did not induce c-fos mRNA expression. Finally, despite its more modest affinity in vitro, F15599 bound to 5-HT1A receptors in vivo almost as potently as F13714. Conclusions and implications: F15599 showed a distinctive activation profiles for 5-HT1A receptor-mediated signalling pathways, unlike those of reference agonists and consistent with functional selectivity at 5-HT1A receptors. In rat, F15599 potently activated signalling in prefrontal cortex, a feature likely to underlie its beneficial effects in models of depression and cognition. PMID:19154445

Discovery of Selective Phosphodiesterase 1 Inhibitors with Memory Enhancing Properties.

PubMed

Dyck, Brian; Branstetter, Bryan; Gharbaoui, Tawfik; Hudson, Andrew R; Breitenbucher, J Guy; Gomez, Laurent; Botrous, Iriny; Marrone, Tami; Barido, Richard; Allerston, Charles K; Cedervall, E Peder; Xu, Rui; Sridhar, Vandana; Barker, Ryan; Aertgeerts, Kathleen; Schmelzer, Kara; Neul, David; Lee, Dong; Massari, Mark Eben; Andersen, Carsten B; Sebring, Kristen; Zhou, Xianbo; Petroski, Robert; Limberis, James; Augustin, Martin; Chun, Lawrence E; Edwards, Thomas E; Peters, Marco; Tabatabaei, Ali

2017-04-27

A series of potent thienotriazolopyrimidinone-based PDE1 inhibitors was discovered. X-ray crystal structures of example compounds from this series in complex with the catalytic domain of PDE1B and PDE10A were determined, allowing optimization of PDE1B potency and PDE selectivity. Reduction of hERG affinity led to greater than a 3000-fold selectivity for PDE1B over hERG. 6-(4-Methoxybenzyl)-9-((tetrahydro-2H-pyran-4-yl)methyl)-8,9,10,11-tetrahydropyrido[4',3':4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-one was identified as an orally bioavailable and brain penetrating PDE1B enzyme inhibitor with potent memory-enhancing effects in a rat model of object recognition memory.

Discovery of a 2,4-Diamino-7-aminoalkoxy-quinazoline as a Potent and Selective Inhibitor of Histone Lysine Methyltransferase G9a†

PubMed Central

Liu, Feng; Chen, Xin; Allali-Hassani, Abdellah; Quinn, Amy M.; Wasney, Gregory A.; Dong, Aiping; Barsyte, Dalia; Kozieradzki, Ivona; Senisterra, Guillermo; Chau, Irene; Siarheyeva, Alena; Kireev, Dmitri B.; Jadhav, Ajit; Herold, J. Martin; Frye, Stephen V.; Arrowsmith, Cheryl H.; Brown, Peter J.; Simeonov, Anton; Vedadi, Masoud; Jin, Jian

2010-01-01

SAR exploration of the 2,4-diamino-6,7-dimethoxyquinazoline template led to the discovery of 8 (UNC0224) as a potent and selective G9a inhibitor. A high resolution X-ray crystal structure of the G9a-8 complex, the first co-crystal structure of G9a with a small molecule inhibitor, was obtained. The co-crystal structure validated our binding hypothesis and will enable structure-based design of novel inhibitors. 8 is a useful tool for investigating the biology of G9a and its roles in chromatin remodeling. PMID:19891491

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.

Synthesis and structure-activity relationships of imidazo[1,2-a]pyrimidin-5(1H)-ones as a novel series of beta isoform selective phosphatidylinositol 3-kinase inhibitors.

PubMed

Lin, Hong; Erhard, Karl; Hardwicke, Mary Ann; Luengo, Juan I; Mack, James F; McSurdy-Freed, Jeanelle; Plant, Ramona; Raha, Kaushik; Rominger, Cynthia M; Sanchez, Robert M; Schaber, Michael D; Schulz, Mark J; Spengler, Michael D; Tedesco, Rosanna; Xie, Ren; Zeng, Jin J; Rivero, Ralph A

2012-03-15

A series of PI3K-beta selective inhibitors, imidazo[1,2-a]-pyrimidin-5(1H)-ones, has been rationally designed based on the docking model of the more potent R enantiomer of TGX-221, identified by a chiral separation, in a PI3K-beta homology model. Synthesis and SAR of this novel chemotype are described. Several compounds in the series demonstrated potent growth inhibition in a PTEN-deficient breast cancer cell line MDA-MB-468 under anchorage independent conditions. Copyright © 2012 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.

8-Aryl- and alkyloxycaffeine analogues as inhibitors of monoamine oxidase.

PubMed

Strydom, Belinda; Bergh, Jacobus J; Petzer, Jacobus P

2011-08-01

Recently it was reported that a series of 8-benzyloxycaffeine analogues are potent reversible inhibitors of human monoamine oxidase (MAO) A and B. In an attempt to discover additional C8 oxy substituents of caffeine that lead to potent MAO inhibition, a series of related 8-aryl- and alkyloxycaffeine analogues were synthesized and their MAO-A and -B inhibition potencies were compared to those of the 8-benzyloxycaffeines. The results document that while the 8-substituted-oxycaffeine analogues inhibited both human MAO isoforms, they displayed a high degree of selectivity for MAO-B. 8-(3-Phenylpropoxy)caffeine, 8-(2-phenoxyethoxy)caffeine and 8-[(5-methylhexyl)oxy]caffeine were found to be the especially potent MAO-B inhibitors with IC(50) values ranging from 0.38 to 0.62 μM. These inhibitors are therefore 2.5-4.6 fold more potent MAO-B inhibitors than is 8-benzyloxycaffeine (IC(50) = 1.77 μM). It is also demonstrated that, analogous to 8-benzyloxycaffeine, halogen substitution on the phenyl ring of the C8 substituent significantly enhances MAO binding affinity. For example, the most potent MAO-B inhibitor of the present series is 8-[2-(4-bromophenoxy)ethoxy]caffeine with an IC(50) value of 0.166 μM. This study also reports possible binding orientations of selected oxy caffeines within the active site cavities of MAO-A and MAO-B. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

The AMPK inhibitor Compound C is a potent AMPK-independent anti-glioma agent

PubMed Central

Liu, Xiaona; Chhipa, Rishi Raj; Nakano, Ichiro; Dasgupta, Biplab

2014-01-01

AMPK is an evolutionarily conserved energy sensor important for cell growth, proliferation, survival and metabolic regulation. Active AMPK inhibits biosynthetic enzymes like mTOR and acetyl CoA carboxylase (required for protein and lipid synthesis, respectively) to ensure that cells maintain essential nutrients and energy during metabolic crisis. Despite our knowledge about this incredibly important kinase, no specific chemical inhibitors are available to examine its function. However, one small molecule known as Compound C (also called dorsomorphin) has been widely used in cell-based, biochemical and in vivo assays as a selective AMPK inhibitor. In nearly all these reports including a recent study in glioma, the biochemical and cellular effects of Compound C has been attributed to its inhibitory action towards AMPK. While examining the status of AMPK activation in human gliomas, we observed that glioblastomas (GBMs) express copious amount of active AMPK. Compound C effectively reduced glioma viability in vitro both by inhibiting proliferation and inducing cell death. As expected, Compound C inhibited AMPK; however, all the antiproliferative effects of this compound were AMPK-independent. Instead, Compound C killed glioma cells by multiple mechanisms including activation of the Calpain/Cathepsin pathway, inhibition of AKT, mTORC1/C2, cell cycle block at G2M and induction of necroptosis and autophagy. Importantly, normal astrocytes were significantly less susceptible to Compound C. In summary, Compound C is an extremely potent anti-glioma agent but we suggest that caution should be taken in interpreting results when this compound is used as an AMPK inhibitor. PMID:24419061

Arisugacins A and B, novel and selective acetylcholinesterase inhibitors from Penicillium sp. FO-4259. I. Screening, taxonomy, fermentation, isolation and biological activity.

PubMed

Kuno, F; Otoguro, K; Shiomi, K; Iwai, Y; Omura, S

1996-08-01

An in vitro screening method for selective acetylcholinesterase (AChE) inhibitors was established. Inhibitory activity of AChE and butyrylcholinesterase (BuChE) was measured and the culture broths of microorganisms that showed selective inhibition against AChE were characterized. By using this method, a strain producing the novel and selective inhibitors of AChE, arisugacins A and B, was picked out among over seven thousand microorganisms tested. Arisugacins were obtained as white powders from the culture broth together with three known compounds, territrems B and C and cyclopenin that also showed selective inhibition against AChE. Arisugacins and territrems are members of the meroterpenoid compounds. They showed potent inhibitory activities against AChE with IC50 values in range of 1.0 approximately 25.8 nM. Furthermore, they showed greater than 2,000-fold more potent inhibition against AChE than BuChE.

Synthesis and SAR of highly potent and selective dopamine D3-receptor antagonists: variations on the 1H-pyrimidin-2-one theme.

PubMed

Geneste, Hervé; Amberg, Wilhelm; Backfisch, Gisela; Beyerbach, Armin; Braje, Wilfried M; Delzer, Jürgen; Haupt, Andreas; Hutchins, Charles W; King, Linda L; Sauer, Daryl R; Unger, Liliane; Wernet, Wolfgang

2006-04-01

In our efforts to further pursue one of the most selective dopamine D(3)-receptor antagonists reported to date, we now describe the synthesis and SAR of novel and highly selective dopamine D(3) antagonists based on a 1H-pyridin-2-one or on a urea scaffold. The most potent compounds exhibited K(i) values toward the D(3) receptor in the nano- to subnanomolar range and high selectivity versus the related D(2) dopamine receptor. Thus, 1H-pyridin-2-one 7b displays oral bioavailability (F=37%) as well as brain penetration (brain plasma ratio 3.7) in rat. Within the urea series, an excellent D(3) versus D(2) selectivity (>100-fold) could be achieved by removal of one NH group (compound 6), although bioavailability (rat) was suboptimal (F<10%). These data significantly enhance our understanding of the D(3) pharmacophore and are expected to lead to novel approaches for the treatment of schizophrenia.

CJ-1639: A Potent and Highly Selective Dopamine D3 Receptor Full Agonist.

PubMed

Chen, Jianyong; Collins, Gregory T; Levant, Beth; Woods, James; Deschamps, Jeffrey R; Wang, Shaomeng

2011-08-11

We have identified several ligands with high binding affinities to the dopamine D3 receptor and excellent selectivity over the D2 and D1 receptors. CJ-1639 (17) binds to the D3 receptor with a K(i) value of 0.50 nM and displays a selectivity of >5,000 times over D2 and D1 receptors in binding assays using dopamine receptors expressed in the native rat brain tissues. CJ-1639 binds to human D3 receptor with a K(i) value of 3.61 nM and displays over >1000-fold selectivity over human D1 and D2 receptors. CJ-1639 is active at 0.01 mg/kg at the dopamine D3 receptor in the rat and only starts to show a modest D2 activity at doses as high as 10 mg/kg. CJ-1639 is the most potent and selective D3 full agonist reported to date.

Structural Basis for Potency and Promiscuity in Poly(ADP-ribose) Polymerase (PARP) and Tankyrase Inhibitors.

PubMed

Thorsell, Ann-Gerd; Ekblad, Torun; Karlberg, Tobias; Löw, Mirjam; Pinto, Ana Filipa; Trésaugues, Lionel; Moche, Martin; Cohen, Michael S; Schüler, Herwig

2017-02-23

Selective inhibitors could help unveil the mechanisms by which inhibition of poly(ADP-ribose) polymerases (PARPs) elicits clinical benefits in cancer therapy. We profiled 10 clinical PARP inhibitors and commonly used research tools for their inhibition of multiple PARP enzymes. We also determined crystal structures of these compounds bound to PARP1 or PARP2. Veliparib and niraparib are selective inhibitors of PARP1 and PARP2; olaparib, rucaparib, and talazoparib are more potent inhibitors of PARP1 but are less selective. PJ34 and UPF1069 are broad PARP inhibitors; PJ34 inserts a flexible moiety into hydrophobic subpockets in various ADP-ribosyltransferases. XAV939 is a promiscuous tankyrase inhibitor and a potent inhibitor of PARP1 in vitro and in cells, whereas IWR1 and AZ-6102 are tankyrase selective. Our biochemical and structural analysis of PARP inhibitor potencies establishes a molecular basis for either selectivity or promiscuity and provides a benchmark for experimental design in assessment of PARP inhibitor effects.

Draft Genome Sequence of the Polyextremophilic Exiguobacterium sp. Strain S17, Isolated from Hyperarsenic Lakes in the Argentinian Puna.

PubMed

Ordoñez, Omar F; Lanzarotti, Esteban; Kurth, Daniel; Gorriti, Marta F; Revale, Santiago; Cortez, Néstor; Vazquez, Martin P; Farías, María E; Turjanski, Adrian G

2013-07-25

Exiguobacterium sp. strain S17 is a moderately halotolerant, arsenic-resistant bacterium that was isolated from Laguna Socompa stromatolites in the Argentinian Puna. The draft genome sequence suggests potent enzyme candidates that are essential for survival under multiple environmental extreme conditions, such as high levels of UV radiation, elevated salinity, and the presence of critical arsenic concentrations.

EVALUATION OF THE MUTAGENIC ACTIVITY OF 3-NBA (3-NITROABENZANTHRONE) USING STRAINS OF SALMONELLA TYPHIMURIUM WITH DIFFERENT LEVELS OF THE ENZYMES NITROREDUCTASE AND ACETYLTRANSFERASE

EPA Science Inventory

The 3-NBA (3-nitro-7H- benz[d,e]antracen-7-one) is extremely potent in the Ames test an useful test for mutagenicity, being a possible inducer of tumors in animals and possible carcinogen for human beings. 3-NBA was previously identified in the exhausts of diesel, particulate mat...

Celecoxib: a potent cyclooxygenase-2 inhibitor in cancer prevention.

PubMed

Kismet, Kemal; Akay, M Turan; Abbasoglu, Osman; Ercan, Aygün

2004-01-01

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely used therapeutic agents in the treatment of pain, inflammation and fever. They may also have a role in the management of cancer prevention, Alzheimer's disease and prophylaxis against cardiovascular disease. These drugs act primarily by inhibiting cyclooxygenase enzyme, which has two isoforms, cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Selective COX-2 inhibitors provide potent anti-inflammatory and analgesic effects without the side effects of gastric and renal toxicity and inhibition of platelet function. Celecoxib is a potent COX-2 inhibitor being developed for the treatment of rheumatoid arthritis and osteoarthritis. Chemoprevention is the use of pharmacological or natural agents to prevent, suppress, interrupt or reverse the process of carcinogenesis. For this purpose, celecoxib is being used for different cancer types. The effects of NSAIDs on tumor growth remain unclear, but are most likely to be multifocal. In this article, we reviewed COX-2 selectivity, the pharmacological properties of celecoxib, the use of celecoxib for cancer prevention and the mechanisms of chemoprevention.

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.

Potent and Selective Amidopyrazole Inhibitors of IRAK4 That Are Efficacious in a Rodent Model of Inflammation

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

McElroy, William T.; Tan, Zheng; Ho, Ginny

IRAK4 is a critical upstream kinase in the IL-1R/TLR signaling pathway. Inhibition of IRAK4 is hypothesized to be beneficial in the treatment of autoimmune related disorders. A screening campaign identified a pyrazole class of IRAK4 inhibitors that were determined by X-ray crystallography to exhibit an unusual binding mode. SAR efforts focused on the identification of a potent and selective inhibitor with good aqueous solubility and rodent pharmacokinetics. Pyrazole C-3 piperidines were well tolerated, with N-sulfonyl analogues generally having good rodent oral exposure but poor solubility. N-Alkyl piperidines exhibited excellent solubility and reduced exposure. Pyrazoles possessing N-1 pyridine and fluorophenyl substituentsmore » were among the most active. Piperazine 32 was a potent enzyme inhibitor with good cellular activity. Compound 32 reduced the in vivo production of proinflammatory cytokines and was orally efficacious in a mouse antibody induced arthritis disease model of inflammation.« less

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

PubMed

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

2017-09-01

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

Social selection is a powerful explanation for prosociality.

PubMed

Nesse, Randolph M

2016-01-01

Cultural group selection helps explain human cooperation, but social selection offers a complementary, more powerful explanation. Just as sexual selection shapes extreme traits that increase matings, social selection shapes extreme traits that make individuals preferred social partners. Self-interested partner choices create strong and possibly runaway selection for prosocial traits, without requiring group selection, kin selection, or reciprocity.

Structure-based design of oxygen-linked macrocyclic kinase inhibitors: discovery of SB1518 and SB1578, potent inhibitors of Janus kinase 2 (JAK2) and Fms-like tyrosine kinase-3 (FLT3)

NASA Astrophysics Data System (ADS)

Poulsen, Anders; William, Anthony; Blanchard, Stéphanie; Lee, Angeline; Nagaraj, Harish; Wang, Haishan; Teo, Eeling; Tan, Evelyn; Goh, Kee Chuan; Dymock, Brian

2012-04-01

Macrocycles from our Aurora project were screened in a kinase panel and were found to be active on other kinase targets, mainly JAKs, FLT3 and CDKs. Subsequently these compounds became leads in our JAK2 project. Macrocycles with a basic nitrogen in the linker form a salt bridge with Asp86 in CDK2 and Asp698 in FLT3. This residue is conserved in most CDKs resulting in potent pan CDK inhibition. One of the main project objectives was to achieve JAK2 potency with 100-fold selectivity against CDKs. Macrocycles with an ether linker have potent JAK2 activity with the ether oxygen forming a hydrogen bond to Ser936. A hydrogen bond to the equivalent residues of JAK3 and most CDKs cannot be formed resulting in good selectivity for JAK2 over JAK3 and CDKs. Further optimization of the macrocyclic linker and side chain increased JAK2 and FLT3 activity as well as improving DMPK properties. The selective JAK2/FLT3 inhibitor 11 (Pacritinib, SB1518) has successfully finished phase 2 clinical trials for myelofibrosis and lymphoma. Another selective JAK2/FLT3 inhibitor, 33 (SB1578), has entered phase 1 clinical development for the non-oncology indication rheumatoid arthritis.

Power laws and extreme values in antibody repertoires

NASA Astrophysics Data System (ADS)

Boyer, Sebastien; Biswas, Dipanwita; Scaramozzino, Natale; Kumar, Ananda Soshee; Nizak, Clément; Rivoire, Olivier

2015-03-01

Evolution by natural selection involves the succession of three steps: mutations, selection and proliferation. We are interested in describing and characterizing the result of selection over a population of many variants. After selection, this population will be dominated by the few best variants, with highest propensity to be selected, or highest ``selectivity.'' We ask the following question: how is the selectivity of the best variants distributed in the population? Extreme value theory, which characterizes the extreme tail of probability distributions in terms of a few universality class, has been proposed to describe it. To test this proposition and identify the relevant universality class, we performed quantitative in vitro experimental selections of libraries of >105 antibodies using the technique of phage display. Data obtained by high-throughput sequencing allows us to fit the selectivity distribution over more than two decades. In most experiments, the results show a striking power law for the selectivity distribution of the top antibodies, consistent with extreme value theory.

FR235222, a fungal metabolite, is a novel immunosuppressant that inhibits mammalian histone deacetylase (HDAC). I. Taxonomy, fermentation, isolation and biological activities.

PubMed

Mori, Hiroaki; Urano, Yasuharu; Abe, Fumie; Furukawa, Satoko; Furukawa, Shigetada; Tsurumi, Yasuhisa; Sakamoto, Kazutoshi; Hashimoto, Michizane; Takase, Shigehiro; Hino, Motohiro; Fujii, Takashi

2003-02-01

A cyclic tetrapeptide FR235222, a novel immunosuppressant, has been isolated from the fermentation broth of a fungus, Acremonium sp. No. 27082. FR235222 showed potent and selective inhibitory effects on both T cell proliferation and lymphokine production. Further study has revealed this compound exhibits potent inhibitory effects on the activity of mammalian histone deacetylases (HDACs).

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.

Furan-2-ylmethylene thiazolidinediones as novel, potent, and selective inhibitors of phosphoinositide 3-kinase gamma.

PubMed

Pomel, Vincent; Klicic, Jasna; Covini, David; Church, Dennis D; Shaw, Jeffrey P; Roulin, Karen; Burgat-Charvillon, Fabienne; Valognes, Delphine; Camps, Montserrat; Chabert, Christian; Gillieron, Corinne; Françon, Bernard; Perrin, Dominique; Leroy, Didier; Gretener, Denise; Nichols, Anthony; Vitte, Pierre Alain; Carboni, Susanna; Rommel, Christian; Schwarz, Matthias K; Rückle, Thomas

2006-06-29

Class I phosphoinositide 3-kinases (PI3Ks), in particular PI3Kgamma, have become attractive drug targets for inflammatory and autoimmune diseases. Here, we disclose a novel series of furan-2-ylmethylene thiazolidinediones as selective, ATP-competitive PI3Kgamma inhibitors. Structure-based design and X-ray crystallography of complexes formed by inhibitors bound to PI3Kgamma identified key pharmacophore features for potency and selectivity. An acidic NH group on the thiazolidinedione moiety and a hydroxy group on the furan-2-yl-phenyl part of the molecule play crucial roles in binding to PI3K and contribute to class IB PI3K selectivity. Compound 26 (AS-252424), a potent and selective small-molecule PI3Kgamma inhibitor emerging from these efforts, was further profiled in three different cellular PI3K assays and shown to be selective for class IB PI3K-mediated cellular effects. Oral administration of 26 in a mouse model of acute peritonitis led to a significant reduction of leukocyte recruitment.

Pyrrolidine-constrained phenethylamines: The design of potent, selective, and pharmacologically efficacious dipeptidyl peptidase IV (DPP4) inhibitors from a lead-like screening hit.

PubMed

Backes, Bradley J; Longenecker, Kenton; Hamilton, Gregory L; Stewart, Kent; Lai, Chunqiu; Kopecka, Hana; von Geldern, Thomas W; Madar, David J; Pei, Zhonghua; Lubben, Thomas H; Zinker, Bradley A; Tian, Zhenping; Ballaron, Stephen J; Stashko, Michael A; Mika, Amanda K; Beno, David W A; Kempf-Grote, Anita J; Black-Schaefer, Candace; Sham, Hing L; Trevillyan, James M

2007-04-01

A novel series of pyrrolidine-constrained phenethylamines were developed as dipeptidyl peptidase IV (DPP4) inhibitors for the treatment of type 2 diabetes. The cyclohexene ring of lead-like screening hit 5 was replaced with a pyrrolidine to enable parallel chemistry, and protein co-crystal structural data guided the optimization of N-substituents. Employing this strategy, a >400x improvement in potency over the initial hit was realized in rapid fashion. Optimized compounds are potent and selective inhibitors with excellent pharmacokinetic profiles. Compound 30 was efficacious in vivo, lowering blood glucose in ZDF rats that were allowed to feed freely on a mixed meal.

Discovery of Novel Tricyclic Heterocycles as Potent and Selective DPP-4 Inhibitors for the Treatment of Type 2 Diabetes

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

Wu, Wen-Lian; Hao, Jinsong; Domalski, Martin

In our efforts to develop second generation DPP-4 inhibitors, we endeavored to identify distinct structures with long-acting (once weekly) potential. Taking advantage of X-ray cocrystal structures of sitagliptin and other DPP-4 inhibitors, such as alogliptin and linagliptin bound to DPP-4, and aided by molecular modeling, we designed several series of heterocyclic compounds as initial targets. During their synthesis, an unexpected chemical transformation provided a novel tricyclic scaffold that was beyond our original design. Capitalizing on this serendipitous discovery, we have elaborated this scaffold into a very potent and selective DPP-4 inhibitor lead series, as highlighted by compound 17c.

Chlamydocin analogs bearing carbonyl group as possible ligand toward zinc atom in histone deacetylases.

PubMed

Bhuiyan, Mohammed P I; Kato, Tamaki; Okauchi, Tatsuo; Nishino, Norikazu; Maeda, Satoko; Nishino, Tomonori G; Yoshida, Minoru

2006-05-15

A series of chlamydocin analogs with various carbonyl functionalities were designed and synthesized as histone deacetylase (HDAC) inhibitors. Chlamydocin is a cyclic tetrapeptide containing an epoxyketone surrogate in the side chain which makes it irreversible inhibitor of HDACs, whereas apicidins are a class of cyclic tetrapeptides that contain an ethylketone moiety as zinc ligand. We replaced the epoxyketone moiety of chlamydocin with several ketones and aldehyde to synthesize potent reversible and selective HDAC inhibitors. The inhibitory activity of the cyclic tetrapeptides against histone deacetylase enzymes were evaluated and the result showed most of them are potent inhibitors. Some of them have remarkable selectivity among the HDACs.

MEN15596, a novel nonpeptide tachykinin NK2 receptor antagonist.

PubMed

Cialdai, Cecilia; Tramontana, Manuela; Patacchini, Riccardo; Lecci, Alessandro; Catalani, Claudio; Catalioto, Rose-Marie; Meini, Stefania; Valenti, Claudio; Altamura, Maria; Giuliani, Sandro; Maggi, Carlo Alberto

2006-11-07

The pharmacological profile of MEN15596 or (6-methyl-benzo[b]thiophene-2-carboxylic acid [1-(2-phenyl-1R-{[1-(tetrahydropyran-4-ylmethyl)-piperidin-4-ylmethyl]-carbamoyl}-ethylcarbamoyl)-cyclopentyl]-amide), a novel potent and selective tachykinin NK2 receptor antagonist endowed with oral activity, is described. At the human recombinant tachykinin NK2 receptor, MEN15596 showed subnanomolar affinity (pKi 10.1) and potently antagonized (pKB 9.1) the neurokinin A-induced intracellular calcium release. MEN15596 selectivity for the tachykinin NK2 receptor was assessed by binding studies at the recombinant tachykinin NK1 (pKi 6.1) and NK3 (pKi 6.4) receptors, and at a number of 34 molecular targets including receptors, transporters and ion channels. In isolated smooth muscle preparations MEN15596 showed a marked species selectivity at the tachykinin NK2 receptor with the highest antagonist potency in guinea-pig colon, human and pig bladder (pKB 9.3, 9.2 and 8.8, respectively) whereas it was three orders of magnitude less potent in the rat and mouse urinary bladder (pKB 6.3 and 5.8, respectively). In agreement with binding experiments, MEN15596 showed low potency in blocking selective NK1 or NK3 receptor agonist-induced contractions of guinea-pig ileum preparations (pA2

Ritonavir and Topical Ocular Corticosteroid Induced Cushing's Syndrome in an Adolescent With HIV-1 Infection.

PubMed

Rainsbury, Paul G; Sharp, Jessica; Tappin, Alison; Hussey, Martin; Lenko, Alexandra; Foster, Caroline

2017-05-01

Cushing's syndrome after topical ocular corticosteroid use is extremely rare. We describe a case of symptomatic Cushing's syndrome in an adolescent male with sight-threatening vernal keratoconjunctivitis on antiretroviral therapy for HIV-1 infection that included ritonavir, a potent cytochrome p450 CYP3A4 inhibitor. CYP3A4 inhibition reduces the metabolism of exogenous corticosteroids leading to suppression of endogenous steroid production and Cushing's syndrome.

Potent selective monoamine oxidase B inhibition by maackiain, a pterocarpan from the roots of Sophora flavescens.

PubMed

Lee, Hyun Woo; Ryu, Hyung Won; Kang, Myung-Gyun; Park, Daeui; Oh, Sei-Ryang; Kim, Hoon

2016-10-01

Monoamine oxidase (MAO) catalyzes the oxidation of monoamines and its two isoforms, MAO-A and MAO-B, break down neurotransmitter amines. Of the compounds isolated from the roots of Sophora flavescens, (-)-maackiain (4), a pterocarpan, was found to potently and selectively inhibit human MAO-B, with an IC50 of 0.68μM, and to have a selectivity index of 126.2 for MAO-B. As compared with other herbal natural products, the IC50 value of 4 for MAO-B is one of the lowest reported to date. Genistein (1) highly, effectively and non-selectively inhibited MAO-A and MAO-B with IC50 values of 3.9μM and 4.1μM, respectively. (-)-4-Hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (2) effectively and non-selectively inhibited MAO-A and MAO-B with IC50 values of 20.3μM and 10.3μM, respectively. In addition, compound 4 reversibly and competitively inhibited MAO-B with a Ki value of 0.054μM. Molecular docking simulation revealed that the binding affinity of 4 for MAO-B (-26.6kcal/mol) was greater than its affinity for MAO-A (-8.3kcal/mol), which was in-line with our inhibitory activity findings. Furthermore, Cys172 of MAO-B was found to be a key residue for hydrogen bonding with compound 4. The findings of this study suggest compound 4 be viewed as a new potent, selective, and reversible MAO-B inhibitor, and that compounds 1 and 2 be considered useful lead compounds for the developments of nonselective and reversible MAO inhibitors for the treatment of disorders like Parkinson's disease, Alzheimer disease, and depression. Copyright © 2016 Elsevier Ltd. All rights reserved.

The solvation structure of alprazolam.

PubMed

Sridhar, Akshay; Johnston, Andrew J; Varathan, Luxmmi; McLain, Sylvia E; Biggin, Philip C

2016-08-10

Alprazolam is a benzodiazepine that is commonly prescribed for the treatment of anxiety and other related disorders. Like other benzodiazepines, it is thought to exert its effect through interaction with GABAA receptors. However, it has also been described as a potent and selective protein interaction inhibitor of bromodomain and extra-terminal (BET) proteins. Indeed, the only crystal structure of alprazolam bound to a protein is a complex between alprazolam and the BRD4 bromodomain. The structure shows that the complex also involves many water interactions that mediate contacts between the drug and the protein, a scenario that exists in many drug-protein complexes. How such waters relate to solvation patterns of small molecules may improve our understanding of what dictates their appearance or absence in bridging positions within complexes and thus will be important in terms of future rational drug-design. Here, we use neutron diffraction in conjunction with molecular dynamics simulations to provide a detailed analysis of how water molecules interact with alprazolam in methanol/water mixtures. The agreement between the neutron diffraction and the molecular dynamics is extremely good. We discuss the results in the context of drug design.

Isolation and characterization of biosurfactant production under extreme environmental conditions by alkali-halo-thermophilic bacteria from Saudi Arabia

PubMed Central

Elazzazy, Ahmed M.; Abdelmoneim, T.S.; Almaghrabi, O.A.

2014-01-01

Twenty three morphologically distinct microbial colonies were isolated from soil and sea water samples, which were collected from Jeddah region, Saudi Arabia for screening of the most potent biosurfactant strains. The isolated bacteria were selected by using different methods as drop collapse test, oil displacement test, blue agar test, blood hemolysis test, emulsification activity and surface tension. The results showed that the ability of Virgibacillus salarius to grow and reduce surface tension under a wide range of pH, salinities and temperatures gives bacteria isolate an advantage in many applications such as pharmaceutical, cosmetics, food industries and bioremediation in marine environment. The biosurfactant production by V. salarius decreased surface tension and emulsifying activity (30 mN/m and 80%, respectively). In addition to reducing the production cost of biosurfactants by tested several plant-derived oils such as jatropha oil, castor oils, jojoba oil, canola oil and cottonseed oil. In this respect the feasibility to reusing old frying oil of sunflower for production rhamnolipids and sophorolipids, their use that lead to solve many ecological and industrial problems. PMID:26150754

Isolation and characterization of biosurfactant production under extreme environmental conditions by alkali-halo-thermophilic bacteria from Saudi Arabia.

PubMed

Elazzazy, Ahmed M; Abdelmoneim, T S; Almaghrabi, O A

2015-07-01

Twenty three morphologically distinct microbial colonies were isolated from soil and sea water samples, which were collected from Jeddah region, Saudi Arabia for screening of the most potent biosurfactant strains. The isolated bacteria were selected by using different methods as drop collapse test, oil displacement test, blue agar test, blood hemolysis test, emulsification activity and surface tension. The results showed that the ability of Virgibacillus salarius to grow and reduce surface tension under a wide range of pH, salinities and temperatures gives bacteria isolate an advantage in many applications such as pharmaceutical, cosmetics, food industries and bioremediation in marine environment. The biosurfactant production by V. salarius decreased surface tension and emulsifying activity (30 mN/m and 80%, respectively). In addition to reducing the production cost of biosurfactants by tested several plant-derived oils such as jatropha oil, castor oils, jojoba oil, canola oil and cottonseed oil. In this respect the feasibility to reusing old frying oil of sunflower for production rhamnolipids and sophorolipids, their use that lead to solve many ecological and industrial problems.

Discovery of Potent and Selective MRCK Inhibitors with Therapeutic Effect on Skin Cancer.

PubMed

Unbekandt, Mathieu; Belshaw, Simone; Bower, Justin; Clarke, Maeve; Cordes, Jacqueline; Crighton, Diane; Croft, Daniel R; Drysdale, Martin J; Garnett, Mathew J; Gill, Kathryn; Gray, Christopher; Greenhalgh, David A; Hall, James A M; Konczal, Jennifer; Lilla, Sergio; McArthur, Duncan; McConnell, Patricia; McDonald, Laura; McGarry, Lynn; McKinnon, Heather; McMenemy, Carol; Mezna, Mokdad; Morrice, Nicolas A; Munro, June; Naylor, Gregory; Rath, Nicola; Schüttelkopf, Alexander W; Sime, Mairi; Olson, Michael F

2018-04-15

The myotonic dystrophy-related Cdc42-binding kinases MRCKα and MRCKβ contribute to the regulation of actin-myosin cytoskeleton organization and dynamics, acting in concert with the Rho-associated coiled-coil kinases ROCK1 and ROCK2. The absence of highly potent and selective MRCK inhibitors has resulted in relatively little knowledge of the potential roles of these kinases in cancer. Here, we report the discovery of the azaindole compounds BDP8900 and BDP9066 as potent and selective MRCK inhibitors that reduce substrate phosphorylation, leading to morphologic changes in cancer cells along with inhibition of their motility and invasive character. In over 750 human cancer cell lines tested, BDP8900 and BDP9066 displayed consistent antiproliferative effects with greatest activity in hematologic cancer cells. Mass spectrometry identified MRCKα S1003 as an autophosphorylation site, enabling development of a phosphorylation-sensitive antibody tool to report on MRCKα status in tumor specimens. In a two-stage chemical carcinogenesis model of murine squamous cell carcinoma, topical treatments reduced MRCKα S1003 autophosphorylation and skin papilloma outgrowth. In parallel work, we validated a phospho-selective antibody with the capability to monitor drug pharmacodynamics. Taken together, our findings establish an important oncogenic role for MRCK in cancer, and they offer an initial preclinical proof of concept for MRCK inhibition as a valid therapeutic strategy. Significance: The development of selective small-molecule inhibitors of the Cdc42-binding MRCK kinases reveals their essential roles in cancer cell viability, migration, and invasive character. Cancer Res; 78(8); 2096-114. ©2018 AACR . ©2018 American Association for Cancer Research.

Fragment-Based Drug Discovery in the Bromodomain and Extra-Terminal Domain Family.

PubMed

Radwan, Mostafa; Serya, Rabah

2017-08-01

Bromodomain and extra-terminal domain (BET) inhibition has emerged recently as a potential therapeutic target for the treatment of many human disorders such as atherosclerosis, inflammatory disorders, chronic obstructive pulmonary disease (COPD), some viral infections, and cancer. Since the discovery of the two potent inhibitors, I-BET762 and JQ1, different research groups have used different techniques to develop novel potent and selective inhibitors. In this review, we will be concerned with the trials that used fragment-based drug discovery (FBDD) approaches to discover or optimize BET inhibitors, also showing fragments that can be further optimized in future projects to reach novel potent BET inhibitors. © 2017 Deutsche Pharmazeutische Gesellschaft.

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

PubMed

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

2016-01-15

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

(1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol (TS-071) is a potent, selective sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor for type 2 diabetes treatment.

PubMed

Kakinuma, Hiroyuki; Oi, Takahiro; Hashimoto-Tsuchiya, Yuko; Arai, Masayuki; Kawakita, Yasunori; Fukasawa, Yoshiki; Iida, Izumi; Hagima, Naoko; Takeuchi, Hiroyuki; Chino, Yukihiro; Asami, Jun; Okumura-Kitajima, Lisa; Io, Fusayo; Yamamoto, Daisuke; Miyata, Noriyuki; Takahashi, Teisuke; Uchida, Saeko; Yamamoto, Koji

2010-04-22

Derivatives of a novel scaffold, C-phenyl 1-thio-D-glucitol, were prepared and evaluated for sodium-dependent glucose cotransporter (SGLT) 2 and SGLT1 inhibition activities. Optimization of substituents on the aromatic rings afforded five compounds with potent and selective SGLT2 inhibition activities. The compounds were evaluated for in vitro human metabolic stability, human serum protein binding (SPB), and Caco-2 permeability. Of them, (1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol (3p) exhibited potent SGLT2 inhibition activity (IC(50) = 2.26 nM), with 1650-fold selectivity over SGLT1. Compound 3p showed good metabolic stability toward cryo-preserved human hepatic clearance, lower SPB, and moderate Caco-2 permeability. Since 3p should have acceptable human pharmacokinetics (PK) properties, it could be a clinical candidate for treating type 2 diabetes. We observed that compound 3p exhibits a blood glucose lowering effect, excellent urinary glucose excretion properties, and promising PK profiles in animals. Phase II clinical trials of 3p (TS-071) are currently ongoing.

Identification of a new class of potent Cdc7 inhibitors designed by putative pharmacophore model: Synthesis and biological evaluation of 2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-ones.

PubMed

Kurasawa, Osamu; Oguro, Yuya; Miyazaki, Tohru; Homma, Misaki; Mori, Kouji; Iwai, Kenichi; Hara, Hideto; Skene, Robert; Hoffman, Isaac; Ohashi, Akihiro; Yoshida, Sei; Ishikawa, Tomoyasu; Cho, Nobuo

2017-04-01

Cell division cycle 7 (Cdc7) is a serine/threonine kinase that plays important roles in the regulation of DNA replication process. A genetic study indicates that Cdc7 inhibition can induce selective tumor-cell death in a p53-dependent manner, suggesting that Cdc7 is an attractive target for the treatment of cancers. In order to identify a new class of potent Cdc7 inhibitors, we generated a putative pharmacophore model based on in silico docking analysis of a known inhibitor with Cdc7 homology model. The pharmacophore model provided a minimum structural motif of Cdc7 inhibitor, by which preliminary medicinal chemistry efforts identified a dihydrothieno[3,2-d]-pyrimidin-4(1H)-one scaffold having a heteroaromatic hinge-binding moiety. The structure-activity relationship (SAR) studies resulted in the discovery of new, potent, and selective Cdc7 inhibitors 14a, c, e. Furthermore, the high selectivity of 14c, e for Cdc7 over Rho-associated protein kinase 1 (ROCK1) is discussed by utilizing a docking study with Cdc7 and ROCK2 crystal structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis, biological evaluation and molecular modeling of 1-oxa-4-thiaspiro- and 1,4-dithiaspiro[4.5]decane derivatives as potent and selective 5-HT1A receptor agonists.

PubMed

Franchini, Silvia; Manasieva, Leda Ivanova; Sorbi, Claudia; Battisti, Umberto M; Fossa, Paola; Cichero, Elena; Denora, Nunzio; Iacobazzi, Rosa Maria; Cilia, Antonio; Pirona, Lorenza; Ronsisvalle, Simone; Aricò, Giuseppina; Brasili, Livio

2017-01-05

Recently, 1-(1,4-dioxaspiro[4,5]dec-2-ylmethyl)-4-(2-methoxyphenyl)piperazine (1) was reported as a potent 5-HT 1A R agonist with a moderate 5-HT 1A R selectivity. In an extension of this work a series of derivatives of 1, obtained by combining different heterocyclic rings with a more flexible amine chain, was synthesized and tested for binding affinity and activity at 5-HT 1A R and α 1 adrenoceptors. The results led to the identification of 14 and 15 as novel 5-HT 1A R partial agonists, the first being outstanding for selectivity (5-HT 1A /α 1d  = 80), the latter for potency (pD 2  = 9.58) and efficacy (E max  = 74%). Theoretical studies of ADME properties shows a good profile for the entire series and MDCKII-MDR1 cells permeability data predict a good BBB permeability of compound 15, which possess a promising neuroprotective activity. Furthermore, in mouse formalin test, compound 15 shows a potent antinociceptive activity suggesting a new strategy for pain control. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Broad and potent HIV-1 neutralization by a human antibody that binds the gp41-120 interface

PubMed Central

Huang, Jinghe; Kang, Byong H.; Pancera, Marie; Lee, Jeong Hyun; Tong, Tommy; Feng, Yu; Georgiev, Ivelin S.; Chuang, Gwo-Yu; Druz, Aliaksandr; Doria-Rose, Nicole A.; Laub, Leo; Sliepen, Kwinten; van Gils, Marit J.; de la Peña, Alba Torrents; Derking, Ronald; Klasse, Per-Johan; Migueles, Stephen A.; Bailer, Robert T.; Alam, Munir; Pugach, Pavel; Haynes, Barton F.; Wyatt, Richard T.; Sanders, Rogier W.; Binley, James M.; Ward, Andrew B.; Mascola, John R.; Kwong, Peter D.; Connors, Mark

2014-01-01

The isolation of human monoclonal antibodies (mAbs) is providing important insights regarding the specificities that underlie broad neutralization of HIV-1 (reviewed in1). Here we report a broad and extremely potent HIV-specific mAb, termed 35O22, which binds novel HIV-1 envelope glycoprotein (Env) epitope. 35O22 neutralized 62% of 181 pseudoviruses with an IC50<50 μg/ml. The median IC50 of neutralized viruses was 0.033 μg/ml, among the most potent thus far described. 35O22 did not bind monomeric forms of Env tested, but did bind the trimeric BG505 SOSIP.664. Mutagenesis and a reconstruction by negative-stain electron microscopy of the Fab in complex with trimer revealed it to bind a conserved epitope, which stretched across gp120 and gp41. The specificity of 35O22 represents a novel site of vulnerability on HIV Env, which serum analysis indicates to be commonly elicited by natural infection. Binding to this new site of vulnerability may thus be an important complement to current mAb-based approaches to immunotherapies, prophylaxis, and vaccine design. PMID:25186731

2-acetylphenol analogs as potent reversible monoamine oxidase inhibitors.

PubMed

Legoabe, Lesetja J; Petzer, Anél; Petzer, Jacobus P

2015-01-01

Based on a previous report that substituted 2-acetylphenols may be promising leads for the design of novel monoamine oxidase (MAO) inhibitors, a series of C5-substituted 2-acetylphenol analogs (15) and related compounds (two) were synthesized and evaluated as inhibitors of human MAO-A and MAO-B. Generally, the study compounds exhibited inhibitory activities against both MAO-A and MAO-B, with selectivity for the B isoform. Among the compounds evaluated, seven compounds exhibited IC50 values <0.01 µM for MAO-B inhibition, with the most selective compound being 17,000-fold selective for MAO-B over the MAO-A isoform. Analyses of the structure-activity relationships for MAO inhibition show that substitution on the C5 position of the 2-acetylphenol moiety is a requirement for MAO-B inhibition, and the benzyloxy substituent is particularly favorable in this regard. This study concludes that C5-substituted 2-acetylphenol analogs are potent and selective MAO-B inhibitors, appropriate for the design of therapies for neurodegenerative disorders such as Parkinson's disease.

Identification and preclinical characterization of AZ-23, a novel, selective, and orally bioavailable inhibitor of the Trk kinase pathway.

PubMed

Thress, Kenneth; Macintyre, Terry; Wang, Haiyun; Whitston, Dave; Liu, Zhong-Ying; Hoffmann, Ethan; Wang, Tao; Brown, Jeffrey L; Webster, Kevin; Omer, Charles; Zage, Peter E; Zeng, Lizhi; Zweidler-McKay, Patrick A

2009-07-01

Tropomyosin-related kinases (TrkA, TrkB, and TrkC) are receptor tyrosine kinases that, along with their ligands, the neurotrophins, are involved in neuronal cell growth, development, and survival. The Trk-neurotrophin pathway may also play a role in tumorigenesis through oncogenic fusions, mutations, and autocrine signaling, prompting the development of novel Trk inhibitors as agents for cancer therapy. This report describes the identification of AZ-23, a novel, potent, and selective Trk kinase inhibitor. In vitro studies with AZ-23 showed improved selectivity over previous compounds and inhibition of Trk kinase activity in cells at low nanomolar concentrations. AZ-23 showed in vivo TrkA kinase inhibition and efficacy in mice following oral administration in a TrkA-driven allograft model and significant tumor growth inhibition in a Trk-expressing xenograft model of neuroblastoma. AZ-23 represents a potent and selective Trk kinase inhibitor from a novel series with the potential for use as a treatment for cancer.

A simple bias correction in linear regression for quantitative trait association under two-tail extreme selection.

PubMed

Kwan, Johnny S H; Kung, Annie W C; Sham, Pak C

2011-09-01

Selective genotyping can increase power in quantitative trait association. One example of selective genotyping is two-tail extreme selection, but simple linear regression analysis gives a biased genetic effect estimate. Here, we present a simple correction for the bias.

Synthesis and evaluation of biaryl derivatives for structural characterization of selective monoamine oxidase B inhibitors toward Parkinson's disease therapy.

PubMed

Yeon, Seul Ki; Choi, Ji Won; Park, Jong-Hyun; Lee, Ye Rim; Kim, Hyeon Jeong; Shin, Su Jeong; Jang, Bo Ko; Kim, Siwon; Bahn, Yong-Sun; Han, Gyoonhee; Lee, Yong Sup; Pae, Ae Nim; Park, Ki Duk

2018-01-01

Benzyloxyphenyl moiety is a common structure of highly potent, selective and reversible inhibitors of monoamine oxidase B (MAO-B), safinamide and sembragiline. We synthesized 4-(benzyloxy)phenyl and biphenyl-4-yl derivatives including halogen substituents on the terminal aryl unit. In addition, we modified the carbon linker between amine group and the biaryl linked unit. Among synthesized compounds, 12c exhibited the most potent and selective MAO-B inhibitory effect (hMAO-B IC 50 : 8.9 nM; >10,000-fold selectivity over MAO-A) as a competitive inhibitor. In addition, 12c showed greater MAO-B inhibitory activity and selectivity compared to well-known MAO-B inhibitors such as selegiline, safinamide and sembragiline. In the MPTP-induced mouse model of Parkinson's disease (PD), 12c significantly protected the tyrosine hydroxylase (TH)-immunopositive DAergic neurons and attenuated the PD-associated behavioral deficits. This study suggests characteristic structures as a MAO-B inhibitor that may provide a good insight for the development of therapeutic agents for PD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular size is important for the safety and selective inhibition of intrinsic factor Xase for fucosylated chondroitin sulfate.

PubMed

Yan, Lufeng; Li, Junhui; Wang, Danli; Ding, Tian; Hu, Yaqin; Ye, Xingqian; Linhardt, Robert J; Chen, Shiguo

2017-12-15

Fucosylated chondroitin sulfate from sea cucumber Isostichopus badionotus (FCS-Ib) showed potent anticoagulant activities without selectivity. The present study focused on developing safe FCS-Ib oligomers showing selective inhibition of intrinsic factor Xase (anti-FXase) prepared through partial N-deacetylation-deaminative cleavage. The N-deacetylation degree was regulated by reaction time, controlling the resulting oligomer distribution. Structure analysis confirmed the selectivity of degradation, and 12 high purity fractions with trisaccharide-repeating units were separated. In vitro anticoagulant assays indicated a decrease in molecular weight (Mw) dramatically reduced activated partial thromboplastin time (APTT), thrombin time (TT), AT-dependent anti-FIIa and anti-FXa activities, while the oligomers retained potent anti-FXase activity until they fell below 3kDa. Meanwhile, human FXII activation and platelet aggregation were markedly reduced with decreasing Mw and were moderate when under 12.0kDa. Thus, fragments of 3-12.0kDa should be safe and effective as selective inhibitors of intrinsic tenase complex for application as clinical anticoagulants. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Natural Product Magnolol as a Lead Structure for the Development of Potent Cannabinoid Receptor Agonists

PubMed Central

Müller, Christa E.

2013-01-01

Magnolol (4-allyl-2-(5-allyl-2-hydroxyphenyl)phenol), the main bioactive constituent of the medicinal plant Magnolia officinalis, and its main metabolite tetrahydromagnolol were recently found to activate cannabinoid (CB) receptors. We now investigated the structure-activity relationships of (tetrahydro)magnolol analogs with variations of the alkyl chains and the phenolic groups and could considerably improve potency. Among the most potent compounds were the dual CB1/CB2 full agonist 2-(2-methoxy-5-propyl-phenyl)-4-hexylphenol (61a, K i CB1∶0.00957 µM; K i CB2∶0.0238 µM), and the CB2-selective partial agonist 2-(2-hydroxy-5-propylphenyl)-4-pentylphenol (60, K i CB1∶0.362 µM; K i CB2∶0.0371 µM), which showed high selectivity versus GPR18 and GPR55. Compound 61b, an isomer of 61a, was the most potent GPR55 antagonist with an IC50 value of 3.25 µM but was non-selective. The relatively simple structures, which possess no stereocenters, are easily accessible in a four- to five-step synthetic procedure from common starting materials. The central reaction step is the well-elaborated Suzuki-Miyaura cross-coupling reaction, which is suitable for a combinatorial chemistry approach. The scaffold is versatile and may be fine-tuned to obtain a broad range of receptor affinities, selectivities and efficacies. PMID:24204944

Antibody Drug Conjugates: Application of Quantitative Pharmacology in Modality Design and Target Selection.

PubMed

Sadekar, S; Figueroa, I; Tabrizi, M

2015-07-01

Antibody drug conjugates (ADCs) are a multi-component modality comprising of an antibody targeting a cell-specific antigen, a potent drug/payload, and a linker that can be processed within cellular compartments to release payload upon internalization. Numerous ADCs are being evaluated in both research and clinical settings within the academic and pharmaceutical industry due to their ability to selectively deliver potent payloads. Hence, there is a clear need to incorporate quantitative approaches during early stages of drug development for effective modality design and target selection. In this review, we describe a quantitative approach and framework for evaluation of the interplay between drug- and systems-dependent properties (i.e., target expression, density, localization, turnover, and affinity) in order to deliver a sufficient amount of a potent payload into the relevant target cells. As discussed, theoretical approaches with particular considerations given to various key properties for the target and modality suggest that delivery of the payload into particular effect cells to be more sensitive to antigen concentrations for targets with slow turnover rates as compared to those with faster internalization rates. Further assessments also suggest that increasing doses beyond the threshold of the target capacity (a function of target internalization and expression) may not impact the maximum amount of payload delivered to the intended effect cells. This article will explore the important application of quantitative sciences in selection of the target and design of ADC modalities.

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.

Identification of methyl violet 2B as a novel blocker of focal adhesion kinase signaling pathway in cancer cells

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

Kim, Hwan; Translational Research Center for Protein Function Control; Kim, Nam Doo

2013-07-26

Highlights: •FAK signaling cascade in cancer cells is profoundly inhibited by methyl violet 2B. •Methyl violet 2B identified by virtual screening is a novel allosteric FAK inhibitor. •Methyl violet 2B possesses extremely high kinase selectivity. •Methyl violet 2B suppresses strongly the proliferation of cancer cells. •Methyl violet 2B inhibits focal adhesion, invasion and migration of cancer cells. -- Abstract: The focal adhesion kinase (FAK) signaling cascade in cancer cells was profoundly inhibited by methyl violet 2B identified with the structure-based virtual screening. Methyl violet 2B was shown to be a non-competitive inhibitor of full-length FAK enzyme vs. ATP. It turnedmore » out that methyl violet 2B possesses extremely high kinase selectivity in biochemical kinase profiling using a large panel of kinases. Anti-proliferative activity measurement against several different cancer cells and Western blot analysis showed that this substance is capable of suppressing significantly the proliferation of cancer cells and is able to strongly block FAK/AKT/MAPK signaling pathways in a dose dependent manner at low nanomolar concentration. Especially, phosphorylation of Tyr925-FAK that is required for full activation of FAK was nearly completely suppressed even with 1 nM of methyl violet 2B in A375P cancer cells. To the best of our knowledge, it has never been reported that methyl violet possesses anti-cancer effects. Moreover, methyl violet 2B significantly inhibited FER kinase phosphorylation that activates FAK in cell. In addition, methyl violet 2B was found to induce cell apoptosis and to exhibit strong inhibitory effects on the focal adhesion, invasion, and migration of A375P cancer cells at low nanomolar concentrations. Taken together, these results show that methyl violet 2B is a novel, potent and selective blocker of FAK signaling cascade, which displays strong anti-proliferative activities against a variety of human cancer cells and suppresses adhesion/migration/invasion of tumor cells.« less

Discovery of PF-04620110, a Potent, Selective, and Orally Bioavailable Inhibitor of DGAT-1

PubMed Central

2011-01-01

Acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final committed step in the biosynthesis of triglycerides. DGAT-1 knockout mice have been shown to be resistant to diet-induced obesity and have increased insulin sensitivity. Thus, inhibition of DGAT-1 may represent an attractive target for the treatment of obesity or type II diabetes. Herein, we report the discovery and characterization of a potent and selective DGAT-1 inhibitor PF-04620110 (3). Compound 3 inhibits DGAT-1 with an IC50 of 19 nM and shows high selectivity versus a broad panel of off-target pharmacologic end points. In vivo DGAT-1 inhibition has been demonstrated through reduction of plasma triglyceride levels in rodents at doses of ≥0.1 mg/kg following a lipid challenge. On the basis of this pharmacologic and pharmacokinetic profile, compound 3 has been advanced to human clinical studies. PMID:24900321

Discovery of PF-04620110, a Potent, Selective, and Orally Bioavailable Inhibitor of DGAT-1.

PubMed

Dow, Robert L; Li, Jian-Cheng; Pence, Michael P; Gibbs, E Michael; LaPerle, Jennifer L; Litchfield, John; Piotrowski, David W; Munchhof, Michael J; Manion, Tara B; Zavadoski, William J; Walker, Gregory S; McPherson, R Kirk; Tapley, Susan; Sugarman, Eliot; Guzman-Perez, Angel; DaSilva-Jardine, Paul

2011-05-12

Acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final committed step in the biosynthesis of triglycerides. DGAT-1 knockout mice have been shown to be resistant to diet-induced obesity and have increased insulin sensitivity. Thus, inhibition of DGAT-1 may represent an attractive target for the treatment of obesity or type II diabetes. Herein, we report the discovery and characterization of a potent and selective DGAT-1 inhibitor PF-04620110 (3). Compound 3 inhibits DGAT-1 with an IC50 of 19 nM and shows high selectivity versus a broad panel of off-target pharmacologic end points. In vivo DGAT-1 inhibition has been demonstrated through reduction of plasma triglyceride levels in rodents at doses of ≥0.1 mg/kg following a lipid challenge. On the basis of this pharmacologic and pharmacokinetic profile, compound 3 has been advanced to human clinical studies.

(2R)-4-Oxo-4[3-(Trifluoromethyl)-5,6-diihydro:1,2,4}triazolo[4,3-a}pyrazin-7(8H)-y1]-1-(2,4,5-trifluorophenyl)butan-2-amine: A Potent, Orally Active Dipeptidyl Peptidase IV Inhibitor for the Treatment of Type 2 Diabetes

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

Kim, D.; Wang, L.; Beconi, M.

2010-11-10

A novel series of {beta}-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC{sub 50} = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes.

Virtual screening of selective inhibitors of phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis

NASA Astrophysics Data System (ADS)

Podshivalov, D. D.; Timofeev, V. I.; Sidorov-Biryukov, D. D.; Kuranova, I. P.

2017-05-01

Bacterial phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis (PPAT Mt) is a convenient target protein for the directed search for selective inhibitors as potent antituberculosis drugs. Four compounds suitable for the detailed investigation of their interactions with PPAT Mt were found by virtual screening. The active-site region of the enzyme was chosen as the ligand-binding site. The positions of the ligands found by the docking were refined by molecular dynamics simulation. The nearest environment of the ligands, the positions of which in the active site of the enzyme were found in a computational experiment, was analyzed. The compounds under consideration were shown to directly interact with functionally important active-site amino-acid residues and block access of substrates to the active site. Therefore, these compounds can be used for the design of selective inhibitors of PPAT Mt as potent antituberculosis drugs.

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.

Structure Activity Relationship Studies of Flavonoids as Potent Inhibitors of Human Platelet 12-hLO, Reticulocyte 15-hLO-1 and Prostate Epithelial 15-hLO-2

PubMed Central

Vasquez-Martinez, Yesseny; Ohri, Rachana V.; Kenyon, Victor; Holman, Theodore R.; Sepúlveda-Boza, Silvia

2007-01-01

Human lipoxygenase (hLO) isozymes have been implicated in a number of disease states and have attracted much attention with respect to their inhibition. One class of inhibitors, the flavonoids, have been shown to be potent lipoxygenase inhibitors but their study has been restricted to those compounds found in nature, which have limited structural variability. We have therefore carried out a comprehensive study to determine the structural requirements for flavonoid potency and selectivity against platelet 12-hLO, reticulocyte 15-hLO-1 and prostate epithelial 15-hLO-2. We conclude from this study that catechols are essential for high potency, that isoflavones and isoflavanones tend to select against 12-hLO, that isoflavans tend to select against 15-hLO-1, but few flavonoids target 15-hLO-2. PMID:17869117

Conformationally constrained opioid ligands: the Dmt-Aba and Dmt-Aia versus Dmt-Tic scaffold.

PubMed

Ballet, Steven; Feytens, Debby; Wachter, Rien De; Vlaeminck, Magali De; Marczak, Ewa D; Salvadori, Severo; Graaf, Chris de; Rognan, Didier; Negri, Lucia; Lattanzi, Roberta; Lazarus, Lawrence H; Tourwé, Dirk; Balboni, Gianfranco

2009-01-15

Replacement of the constrained phenylalanine analogue 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) in the opioid Dmt-Tic-Gly-NH-Bn scaffold by the 4-amino-1,2,4,5-tetrahydro-indolo[2,3-c]azepin-3-one (Aia) and 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-one (Aba) scaffolds has led to the discovery of novel potent mu-selective agonists (Structures 5 and 12) as well as potent and selective delta-opioid receptor antagonists (Structures 9 and 15). Both stereochemistry and N-terminal N,N-dimethylation proved to be crucial factors for opioid receptor selectivity and functional bioactivity in the investigated small peptidomimetic templates. In addition to the in vitro pharmacological evaluation, automated docking models of Dmt-Tic and Dmt-Aba analogues were constructed in order to rationalize the observed structure-activity data.

Conformationally constrained opioid ligands: The Dmt-Aba and Dmt-Aia vs. Dmt-Tic scaffold

PubMed Central

Ballet, Steven; Feytens, Debby; De Wachter, Rien; De Vlaeminck, Magali; Marczak, Ewa D.; Salvadori, Severo; de Graaf, Chris; Rognan, Didier; Negri, Lucia; Lattanzi, Roberta; Lazarus, Lawrence H.; Tourwé, Dirk; Balboni, Gianfranco

2009-01-01

Replacement of the constrained phenylalanine analogue 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) in the opioid Dmt-Tic-Gly-NH-Bn scaffold by the 4-amino-1,2,4,5-tetrahydro-indolo[2,3-c]azepin-3-one (Aia) and 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-one (Aba) scaffolds has led to the discovery of novel potent μ-selective agonists (Structures 5 and 12) as well as potent and selective δ-opioid receptor antagonists (Structures 9 and 15). Both stereochemistry and N-terminal N,N-dimethylation proved to be crucial factors for opioid receptor selectivity and functional bioactivity in the investigated small peptidomimetic templates. In addition to the in vitro pharmacological evaluation, automated docking models of Dmt-Tic and Dmt-Aba analogues were constructed in order to rationalize the observed structure-activity data. PMID:19062273

Pharmacological profile of CS-3150, a novel, highly potent and selective non-steroidal mineralocorticoid receptor antagonist.

PubMed

Arai, Kiyoshi; Homma, Tsuyoshi; Morikawa, Yuka; Ubukata, Naoko; Tsuruoka, Hiyoyuki; Aoki, Kazumasa; Ishikawa, Hirokazu; Mizuno, Makoto; Sada, Toshio

2015-08-15

The present study was designed to characterize the pharmacological profile of CS-3150, a novel non-steroidal mineralocorticoid receptor antagonist. In the radioligand-binding assay, CS-3150 inhibited (3)H-aldosterone binding to mineralocorticoid receptor with an IC50 value of 9.4nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 36 and 713nM, respectively. CS-3150 also showed at least 1000-fold higher selectivity for mineralocorticoid receptor over other steroid hormone receptors, glucocorticoid receptor, androgen receptor and progesterone receptor. In the reporter gene assay, CS-3150 inhibited aldosterone-induced transcriptional activation of human mineralocorticoid receptor with an IC50 value of 3.7nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 66 and 970nM, respectively. CS-3150 had no agonistic effect on mineralocorticoid receptor and did not show any antagonistic or agonistic effect on glucocorticoid receptor, androgen receptor and progesterone receptor even at the high concentration of 5μM. In adrenalectomized rats, single oral administration of CS-3150 suppressed aldosterone-induced decrease in urinary Na(+)/K(+) ratio, an index of in vivo mineralocorticoid receptor activation, and this suppressive effect was more potent and longer-lasting than that of spironolactone and eplerenone. Chronic treatment with CS-3150 inhibited blood pressure elevation induced by deoxycorticosterone acetate (DOCA)/salt-loading to rats, and this antihypertensive effect was more potent than that of spironolactone and eplerenone. These findings indicate that CS-3150 is a selective and highly potent mineralocorticoid receptor antagonist with long-lasting oral activity. This agent could be useful for the treatment of hypertension, cardiovascular and renal disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

The Potent ALK Inhibitor Brigatinib (AP26113) Overcomes Mechanisms of Resistance to First- and Second-Generation ALK Inhibitors in Preclinical Models.

PubMed

Zhang, Sen; Anjum, Rana; Squillace, Rachel; Nadworny, Sara; Zhou, Tianjun; Keats, Jeff; Ning, Yaoyu; Wardwell, Scott D; Miller, David; Song, Youngchul; Eichinger, Lindsey; Moran, Lauren; Huang, Wei-Sheng; Liu, Shuangying; Zou, Dong; Wang, Yihan; Mohemmad, Qurish; Jang, Hyun Gyung; Ye, Emily; Narasimhan, Narayana; Wang, Frank; Miret, Juan; Zhu, Xiaotian; Clackson, Tim; Dalgarno, David; Shakespeare, William C; Rivera, Victor M

2016-11-15

Non-small cell lung cancers (NSCLCs) harboring ALK gene rearrangements (ALK + ) typically become resistant to the first-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI) crizotinib through development of secondary resistance mutations in ALK or disease progression in the brain. Mutations that confer resistance to second-generation ALK TKIs ceritinib and alectinib have also been identified. Here, we report the structure and first comprehensive preclinical evaluation of the next-generation ALK TKI brigatinib. A kinase screen was performed to evaluate the selectivity profile of brigatinib. The cellular and in vivo activities of ALK TKIs were compared using engineered and cancer-derived cell lines. The brigatinib-ALK co-structure was determined. Brigatinib potently inhibits ALK and ROS1, with a high degree of selectivity over more than 250 kinases. Across a panel of ALK + cell lines, brigatinib inhibited native ALK (IC 50 , 10 nmol/L) with 12-fold greater potency than crizotinib. Superior efficacy of brigatinib was also observed in mice with ALK + tumors implanted subcutaneously or intracranially. Brigatinib maintained substantial activity against all 17 secondary ALK mutants tested in cellular assays and exhibited a superior inhibitory profile compared with crizotinib, ceritinib, and alectinib at clinically achievable concentrations. Brigatinib was the only TKI to maintain substantial activity against the most recalcitrant ALK resistance mutation, G1202R. The unique, potent, and pan-ALK mutant activity of brigatinib could be rationalized by structural analyses. Brigatinib is a highly potent and selective ALK inhibitor. These findings provide the molecular basis for the promising activity being observed in ALK + , crizotinib-resistant patients with NSCLC being treated with brigatinib in clinical trials. Clin Cancer Res; 22(22); 5527-38. ©2016 AACR. ©2016 American Association for Cancer Research.

Synthesis of Cryptophycin Affinity Labels and Tubulin Labeling

DTIC Science & Technology

2006-05-01

Nostoc sp.), are a new and potent tumor-selective class of tubulin-binding antimitotic agents1 that show excellent activity against MDR cancer cell...lines and were exceptionally active against mammary derived tumors.2,3 Cryptophycin-1 (1, Fig. 1) is the major cytotoxin in Nostoc sp.4,5 and...arenastatin A), isolated from the Okinawan marine sponge Dysidea arenaria6 and later from Nostoc sp. strain GSV 224,7 is also a potent inhibitor of tubulin

Synthesis of Cryptophycin Affinity Labels and Tubulin Labeling

DTIC Science & Technology

2004-05-01

isolated from blue-green algae ( Nostoc sp.), are a new and potent tumor-selective class of tubulin-binding antimitotic agents that show excellent activity... Nostoc sp.3𔃾 and displays IC 50 values in the pM range. Of special importance is the reduced susceptibility of the cryptophycins to P-glycoprotein...also named arenastatin A), isolated from the Okinawan marine sponge Dysidea arenaria5 and later from Nostoc sp. strain GSV 224,6 is also a potent

Synthesis of Cryptophycin Affinity Labels and Tubulin Labeling

DTIC Science & Technology

2005-05-01

isolated from blue-green algae ( Nostoc sp.), are a new and potent tumor-selective class of tubulin-binding antimitotic agents’ that show excellent activity... Nostoc sp. 4𔃿 and displays IC 5 0 values in the pM range. Of special importance is the reduced susceptibility of the cryptophycins to P-glycoprotein...also named arenastatin A), isolated from the Okinawan marine sponge Dysidea arenaria6 and later from Nostoc sp. strain GSV 224,7 is also a potent

Discovery and structure-based design of 4,6-diaminonicotinamides as potent and selective IRAK4 inhibitors

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

Bhide, Rajeev S.; Keon, Alec; Weigelt, Carolyn

2017-11-01

The identification of small molecule inhibitors of IRAK4 for the treatment of autoimmune diseases has been an area of intense research. We discovered novel 4,6-diaminonicotinamides which potently inhibit IRAK4. Optimization efforts were aided by X-ray crystal structures of inhibitors bound to IRAK4. Structure activity relationship (SAR) studies led to the identification of compound 29 which exhibited sub-micromolar potency in a LTA stimulated cellular assay.

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.

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.

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.

Probing the coagulation pathway with aptamers identifies combinations that synergistically inhibit blood clot formation

PubMed Central

Bompiani, Kristin M; Lohrmann, Jens L; Pitoc, George A; Frederiksen, James W; Mackensen, George B; Sullenger, Bruce A

2014-01-01

SUMMARY Coordinated enzymatic reactions regulate blood clot generation. To explore the contributions of various coagulation enzymes in this process, we utilized a panel of aptamers against factors VIIa, IXa, Xa, and prothrombin. Each aptamer dose-dependently inhibited clot formation, yet none was able to completely impede this process in highly procoagulant settings. However several combinations of two aptamers synergistically impaired clot formation. One extremely potent aptamer combination was able to maintain human blood fluidity even during extracorporeal circulation, a highly procoagulant setting encountered during cardiopulmonary bypass surgery. Moreover, this aptamer cocktail could be rapidly reversed with antidotes to restore normal hemostasis, indicating that even highly potent aptamer combinations can be rapidly controlled. These studies highlight the potential utility of using sets of aptamers to probe the functions of proteins in molecular pathways for research and therapeutic ends. PMID:25065530

Identification of Genetically Modified Maraba Virus as an Oncolytic Rhabdovirus

PubMed Central

Brun, Jan; McManus, Dan; Lefebvre, Charles; Hu, Kang; Falls, Theresa; Atkins, Harold; Bell, John C; McCart, J. Andrea; Mahoney, Douglas; Stojdl, David F

2010-01-01

To expand our current array of safe and potent oncolytic viruses, we screened a variety of wild-type (WT) rhabdoviruses against a panel of tumor cell lines. Our screen identified a number of viruses with varying degrees of killing activity. Maraba virus was the most potent of these strains. We built a recombinant system for the Maraba virus platform, engineered a series of attenuating mutations to expand its therapeutic index, and tested their potency in vitro and in vivo. A double mutant (MG1) strain containing both G protein (Q242R) and M protein (L123W) mutations attenuated Maraba virus in normal diploid cell lines, yet appeared to be hypervirulent in cancer cells. This selective attenuation was mediated through interferon (IFN)-dependent and -independent mechanisms. Finally, the Maraba MG1 strain had a 100-fold greater maximum tolerable dose (MTD) than WT Maraba in vivo and resulted in durable cures when systemically administered in syngeneic and xenograft models. In summary, we report a potent new oncolytic rhabdovirus platform with unique tumor-selective attenuating mutations. PMID:20551913

Identification of genetically modified Maraba virus as an oncolytic rhabdovirus.

PubMed

Brun, Jan; McManus, Dan; Lefebvre, Charles; Hu, Kang; Falls, Theresa; Atkins, Harold; Bell, John C; McCart, J Andrea; Mahoney, Douglas; Stojdl, David F

2010-08-01

To expand our current array of safe and potent oncolytic viruses, we screened a variety of wild-type (WT) rhabdoviruses against a panel of tumor cell lines. Our screen identified a number of viruses with varying degrees of killing activity. Maraba virus was the most potent of these strains. We built a recombinant system for the Maraba virus platform, engineered a series of attenuating mutations to expand its therapeutic index, and tested their potency in vitro and in vivo. A double mutant (MG1) strain containing both G protein (Q242R) and M protein (L123W) mutations attenuated Maraba virus in normal diploid cell lines, yet appeared to be hypervirulent in cancer cells. This selective attenuation was mediated through interferon (IFN)-dependent and -independent mechanisms. Finally, the Maraba MG1 strain had a 100-fold greater maximum tolerable dose (MTD) than WT Maraba in vivo and resulted in durable cures when systemically administered in syngeneic and xenograft models. In summary, we report a potent new oncolytic rhabdovirus platform with unique tumor-selective attenuating mutations.

Receptor-selective, peptidase-resistant agonists at neurokinin NK-1 and NK-2 receptors: new tools for investigating neurokinin function.

PubMed

Hagan, R M; Ireland, S J; Jordan, C C; Beresford, I J; Deal, M J; Ward, P

1991-06-01

The pharmacological profiles of two novel neurokinin agonists have been investigated. delta Ava[L-Pro9,N-MeLeu10]SP(7-11) (GR73632) and [Lys3,Gly8-R-gamma-lactam-Leu9] NKA(3-10) (GR64349) are potent and selective agonists at NK-1 and NK-2 receptors respectively. In the guinea-pig isolated trachea preparation, contractions induced by these agonists were largely unaffected by inclusion of peptidase inhibitors in the bathing medium, indicating that these agonists are resistant to metabolism by peptidases. In the anaesthetised guinea-pig, both agonists were more potent bronchoconstrictor agents than either NKA or the SP analogue, SP methylester. In the anaesthetised rat, the NK-1 agonist, GR73632 was more potent than SP, NKA or NKB at causing the histamine-independent extravasation of plasma proteins into the skin after intradermal administration. The NK-2 agonist, GR64349 and the NK-3 agonist, senktide were without significant effect in this model. These agonists are useful tools for characterizing neurokinin receptor-mediated actions both in vitro and in vivo.

Researchers unmask secret to long-lasting effects of botulinum neurotoxin A in motor neurons | Center for Cancer Research

Cancer.gov

A team of scientists led by the Center for Cancer Research's Allan M. Weissman, M.D., and Yien Che Tsai, Ph.D., has discovered a molecular mechanism that explains the extreme toxicity of botulinum neurotoxin A (BoNT/A), the most potent BoNT strain. The discovery, published June 5 in PNAS, also identifies a molecular target that the researchers hope will eventually lead to

Creation of a Novel Class of Potent and Selective MutT Homologue 1 (MTH1) Inhibitors Using Fragment-Based Screening and Structure-Based Drug Design.

PubMed

Rahm, Fredrik; Viklund, Jenny; Trésaugues, Lionel; Ellermann, Manuel; Giese, Anja; Ericsson, Ulrika; Forsblom, Rickard; Ginman, Tobias; Günther, Judith; Hallberg, Kenth; Lindström, Johan; Persson, Lars Boukharta; Silvander, Camilla; Talagas, Antoine; Díaz-Sáez, Laura; Fedorov, Oleg; Huber, Kilian V M; Panagakou, Ioanna; Siejka, Paulina; Gorjánácz, Mátyás; Bauser, Marcus; Andersson, Martin

2018-03-22

Recent literature has both suggested and questioned MTH1 as a novel cancer target. BAY-707 was just published as a target validation small molecule probe for assessing the effects of pharmacological inhibition of MTH1 on tumor cell survival, both in vitro and in vivo. (1) In this report, we describe the medicinal chemistry program creating BAY-707, where fragment-based methods were used to develop a series of highly potent and selective MTH1 inhibitors. Using structure-based drug design and rational medicinal chemistry approaches, the potency was increased over 10,000 times from the fragment starting point while maintaining high ligand efficiency and drug-like properties.

Phage Display Derived IgNAR V Region Binding Domains for Therapeutic Development.

PubMed

Ubah, Obinna C; Barelle, Caroline J; Buschhaus, Magdalena J; Porter, Andrew J

2016-01-01

Phage display technology has revolutionized the science of drug discovery by transforming the generation and manipulation of ligands, such as antibody fragments, enzymes, and peptides. The basis of this technology is the expression of recombinant proteins or peptides fused to a phage coat protein, and subsequent isolation of ligands based on a variety of catalytic, physicochemical/binding kinetic and/or biological characteristics. An incredible number of diagnostic and therapeutic domains have been successfully isolated using phage display technology. The variable domain of the New Antigen Receptors (VNAR) found in cartilaginous fish, is also amenable to phage display selection. Whilst not an antibody, VNARs are unquestionable the oldest (450 million years), and smallest antigen binding, single-domains so far identified in the vertebrate kingdom. Their role as an integral part of the adaptive immune system of sharks has been well established, enhancing our understanding of the evolutionary origins of humoral immunity and the unusual but divergent ancestry of the VNARs themselves. VNARs exhibit remarkable physicochemical properties, such as small size, stability in extreme conditions, solubility, molecular flexibility, high affinity and selectivity for target. The purpose of this review is to illustrate the important role phage display has played in the isolation and characterization of potent therapeutic and diagnostic VNAR domains. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Development of HuperTacrines as non-toxic, cholinesterase inhibitors for the potential treatment of Alzheimer's disease.

PubMed

Chioua, Mourad; Pérez, Marta; Bautista-Aguilera, Oscar M; Yañez, Matilde; López, Manuela G; Romero, Alejandro; Cacabelos, Ramón; de la Bellacasa, Raimon Puig; Brogi, Simone; Butini, Stefania; Borrell, José I; Marco-Contelles, Jose

2015-01-01

This paper describes our preliminary results on the ADMET, synthesis, biochemical evaluation, and molecular modeling of racemic HuperTacrines (HT), new hybrids resulting from the juxtaposition of huperzine A and tacrine for the potential treatment of Alzheimer's disease (AD). The synthesis of these HT was executed by Friedländer-type reactions of 2-amino-6-oxo-1,6-dihydropyridine-3-carbonitriles, or 7-amino-2-oxo-1,2,3,4-tetrahydro-1,6-naphthyridine- 8-carbonitriles, with cyclohexanone. In the biochemical evaluation, initial and particular attention was devoted to test their toxicity on human hepatoma cells, followed by the in vitro inhibition of human cholinesterases (hAChE, and hBuChE), and the kinetics/mechanism of the inhibition of the most potent HT; simultaneous molecular modeling on the best HT provided the key binding interactions with the human cholinesterases. >From these analyses, (±)-5-amino-3-methyl- 3,4,6,7,8,9-hexahydrobenzo[b][1,8]naphthyridin-2(1H)-one (HT1) and (±)-5-amino-3-(2,6-dichlorophenyl)-3,4,6,7,8,9- hexahydrobenzo[b][1,8]naphthyridin-2(1H)-one (HT3) have emerged as characterized by extremely low liver toxicity reversible mixed-type, selective hAChE and, quite selective irreversible hBuChEIs, respectively, showing also good druglike properties for AD-targeted drugs.

Potent and selective agonists of alpha-melanotropin (alphaMSH) action at human melanocortin receptor 5; linear analogs of alpha-melanotropin.

PubMed

Bednarek, Maria A; MacNeil, Tanya; Tang, Rui; Fong, Tung M; Cabello, M Angeles; Maroto, Marta; Teran, Ana

2007-05-01

Alpha-melanotropin, Ac-Ser(1)-Tyr-Ser-Met-Glu-His(6)-Phe(7)-Arg(8)-Trp(9)-Gly-Lys-Pro-Val(13)-NH(2)(1), is a non-selective endogenous agonist for the melanocortin receptor 5; the receptor present in various peripheral tissues and in the brain, cortex and cerebellum. Most of the synthetic analogs of alphaMSH, including a broadly used and more potent the NDP-alphaMSH peptide, Ac-Ser(1)-Tyr-Ser-Nle(4)-Glu-His(6)-D-Phe(7)-Arg(8)-Trp(9)-Gly-Lys-Pro-Val(13)-NH(2), are also not particularly selective for MC5R. To elucidate physiological functions of the melanocortin receptor 5 in rodents and humans, the receptor subtype selective research tools are needed. We report herein syntheses and pharmacological evaluation in vitro of several analogs of NDP-alphaMSH which are highly potent and specific agonists for the human MC5R. The new linear peptides, of structures and solubility properties similar to those of the endogenous ligand alphaMSH, are exemplified by compound 7, Ac-Ser(1)-Tyr-Ser-Met-Glu-Oic(6)-D-4,4'-Bip(7)-Pip(8)-Trp(9)-Gly-Lys-Pro-Val(13)-NH(2) (Oic: octahydroindole-2-COOH, 4,4'-Bip: 4,4'-biphenylalanine, Pip: pipecolic acid), shortly NODBP-alphaMSH, which has an IC(50)=0.74 nM (binding assay) and EC(50)=0.41 (cAMP production assay) at hMC5R nM and greater than 3500-fold selectivity with respect to the melanocortin receptors 1b, 3 and 4. A shorter peptide derived from NODBP-alphaMSH: Ac-Nle-Glu-Oic(6)-D-4,4'-Bip(7)-Pip(8)-Trp(9) -NH(2) (17) was measured to be an agonist only 10-fold less potent at hMC5R than the full length parent peptide. In the structure of this smaller analog, the Nle-Glu-Oic(6)-D-4,4'-Bip(7)-Pip(8) segment was found to be critical for high agonist potency, while the C-terminal Trp(9) residue was shown to be required for high hMC5R selectivity versus hMC1b,3,4R.

A novel prediction approach for antimalarial activities of Trimethoprim, Pyrimethamine, and Cycloguanil analogues using extremely randomized trees.

PubMed

Nattee, Cholwich; Khamsemanan, Nirattaya; Lawtrakul, Luckhana; Toochinda, Pisanu; Hannongbua, Supa

2017-01-01

Malaria is still one of the most serious diseases in tropical regions. This is due in part to the high resistance against available drugs for the inhibition of parasites, Plasmodium, the cause of the disease. New potent compounds with high clinical utility are urgently needed. In this work, we created a novel model using a regression tree to study structure-activity relationships and predict the inhibition constant, K i of three different antimalarial analogues (Trimethoprim, Pyrimethamine, and Cycloguanil) based on their molecular descriptors. To the best of our knowledge, this work is the first attempt to study the structure-activity relationships of all three analogues combined. The most relevant descriptors and appropriate parameters of the regression tree are harvested using extremely randomized trees. These descriptors are water accessible surface area, Log of the aqueous solubility, total hydrophobic van der Waals surface area, and molecular refractivity. Out of all possible combinations of these selected parameters and descriptors, the tree with the strongest coefficient of determination is selected to be our prediction model. Predicted K i values from the proposed model show a strong coefficient of determination, R 2 =0.996, to experimental K i values. From the structure of the regression tree, compounds with high accessible surface area of all hydrophobic atoms (ASA_H) and low aqueous solubility of inhibitors (Log S) generally possess low K i values. Our prediction model can also be utilized as a screening test for new antimalarial drug compounds which may reduce the time and expenses for new drug development. New compounds with high predicted K i should be excluded from further drug development. It is also our inference that a threshold of ASA_H greater than 575.80 and Log S less than or equal to -4.36 is a sufficient condition for a new compound to possess a low K i . Copyright © 2016 Elsevier Inc. All rights reserved.

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

Mechanism of Action of Bolandiol (19-Nortestosterone-3β,17β-Diol), a Unique Anabolic Steroid with Androgenic, Estrogenic, and Progestational Activities*

PubMed Central

Attardi, Barbara J.; Page, Stephanie T.; Hild, Sheri A.; Coss, Christopher C.; Matsumoto, Alvin M.

2009-01-01

Bolandiol is a synthetic anabolic steroid that increases lean body mass and bone mineral density without significant stimulation of sex accessory glands in castrate adult male rats. Since bolandiol suppresses gonadotropins and endogenous testosterone (T) production, we investigated its mechanism of action. We compared the potency of bolandiol in vitro and in vivo with T, 5α-dihydrotestosterone (DHT), 19-nortestosterone (19-NT) and estradiol (E2). Bolandiol bound with lower affinity to the recombinant rat androgen receptor (AR) than the other androgens and had low, but measurable, affinity for recombinant human progestin receptors (PR-A, PR-B), and estrogen receptors (ERα and β-1). Functional agonist activity was assessed in transcription assays mediated by AR, PR, or ER. Bolandiol was stimulatory in all these assays, but only 4–9% as potent as T, DHT, and 19-NT via AR, 1% as potent as progesterone via PR, and 3% and 1% as potent as E2 acting through ERα or ERβ, respectively. In immature castrate rats, bolandiol was equipotent to T in stimulating growth of the levator ani muscle but less potent than T in stimulating growth of the sex accessory glands. Bolandiol also stimulated uterine weight increases in immature female rats, which were partly blocked by ICI 182,780, but it was not aromatized in vitro by recombinant human aromatase. In contrast to T, stimulation of sex accessory gland weights by bolandiol was not inhibited by concomitant treatment with the dual 5α-reductase inhibitor dutasteride. As bolandiol exhibits tissue selectivity in vivo, it may act via AR, PR, and/or ER, utilize alternative signaling pathway(s) or transcriptional coregulators, and/or be metabolized to a more potent selective steroid. PMID:19941958

Conditional Cytotoxic Anti-HIV Gene Therapy for Selectable Cell Modification

PubMed Central

Garg, Himanshu; Joshi, Anjali

2016-01-01

Gene therapy remains one of the potential strategies to achieve a cure for HIV infection. One of the major limitations of anti-HIV gene therapy concerns recovering an adequate number of modified cells to generate an HIV-proof immune system. Our study addresses this issue by developing a methodology that can mark conditional vector-transformed cells for selection and subsequently target HIV-infected cells for elimination by treatment with ganciclovir (GCV). We used the herpes simplex virus thymidine kinase (TK) mutant SR39, which is highly potent at killing cells at low GCV concentrations. This gene was cloned into a conditional HIV vector, pNL-GFPRRESA, which expresses the gene of interest as well as green fluorescent protein (GFP) in the presence of HIV Tat protein. We show here that TK-SR39 was more potent that wild-type TK (TK-WT) at eliminating infected cells at lower concentrations of GCV. As the vector expresses GFP in the presence of Tat, transient expression of Tat either by Tat RNA transfection or transduction by a nonintegrating lentiviral (NIL) vector marked the cells with GFP for selection. In cells selected by this strategy, TK-SR39 was more potent at limiting virus replication than TK-WT. Finally, in Jurkat cells modified and selected by this approach, infection with CXCR4-tropic Lai virus could be suppressed by treatment with GCV. GCV treatment limited the number of HIV-infected cells, virus production, as well as virus-induced cytopathic effects in this model. We provide proof of principle that TK-SR39 in a conditional HIV vector can provide a safe and effective anti-HIV strategy. PMID:26800572

Conditional Cytotoxic Anti-HIV Gene Therapy for Selectable Cell Modification.

PubMed

Garg, Himanshu; Joshi, Anjali

2016-05-01

Gene therapy remains one of the potential strategies to achieve a cure for HIV infection. One of the major limitations of anti-HIV gene therapy concerns recovering an adequate number of modified cells to generate an HIV-proof immune system. Our study addresses this issue by developing a methodology that can mark conditional vector-transformed cells for selection and subsequently target HIV-infected cells for elimination by treatment with ganciclovir (GCV). We used the herpes simplex virus thymidine kinase (TK) mutant SR39, which is highly potent at killing cells at low GCV concentrations. This gene was cloned into a conditional HIV vector, pNL-GFPRRESA, which expresses the gene of interest as well as green fluorescent protein (GFP) in the presence of HIV Tat protein. We show here that TK-SR39 was more potent that wild-type TK (TK-WT) at eliminating infected cells at lower concentrations of GCV. As the vector expresses GFP in the presence of Tat, transient expression of Tat either by Tat RNA transfection or transduction by a nonintegrating lentiviral (NIL) vector marked the cells with GFP for selection. In cells selected by this strategy, TK-SR39 was more potent at limiting virus replication than TK-WT. Finally, in Jurkat cells modified and selected by this approach, infection with CXCR4-tropic Lai virus could be suppressed by treatment with GCV. GCV treatment limited the number of HIV-infected cells, virus production, as well as virus-induced cytopathic effects in this model. We provide proof of principle that TK-SR39 in a conditional HIV vector can provide a safe and effective anti-HIV strategy.

Potent and selective CC chemokine receptor 1 antagonists labeled with carbon-13, carbon-14, and tritium.

PubMed

Latli, Bachir; Hrapchak, Matt; Cheveliakov, Maxim; Reeves, Jonathan T; Marsini, Maurice; Busacca, Carl A; Senanayake, Chris H

2018-05-15

1-(4-Fluorophenyl)-1H-pyrazolo[3,4-c]pyridine-4-carboxylic acid (2-methanesulfonyl-pyridin-4-ylmethyl)-amide (1) and its analogs (2) and (3) are potent CCR1 antagonists intended for the treatment of rheumatoid arthritis. The detailed syntheses of these 3 compounds labeled with carbon-13 as well as the preparation of (1) and (2) labeled with carbon-14, and (1) labeled with tritium, are described. Copyright © 2018 John Wiley & Sons, Ltd.

Synthesis and characterization of trans-4-(4-chlorophenyl)pyrrolidine-3-carboxamides of piperazinecyclohexanes as ligands for the melanocortin-4 receptor.

PubMed

Chen, Caroline W; Tran, Joe A; Fleck, Beth A; Tucci, Fabio C; Jiang, Wanlong; Chen, Chen

2007-12-15

A series of trans-N-alkyl-4-(4-chlorophenyl)pyrrolidine-3-carboxamides of piperazinecyclohexanemethylamines was synthesized and characterized for binding and function at the melanocortin-4 receptor (MC4R), and several potent benzylamine derivatives were identified. Compound 18 v was found to bind MC4R with potent affinity (K(i)=0.5 nM) and high selectivity over the other melanocortin subtypes and behaved as a functional antagonist (IC(50)=48 nM).

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.

A precisely substituted benzopyran targets androgen refractory prostate cancer cells through selective modulation of estrogen receptors

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

Kumar, Rajeev; Verma, Vikas; Sharma, Vikas

Dietary consumption of phytoestrogens like genistein has been linked with lower incidence of prostate cancer. The estradiol-like benzopyran core of genistein confers estrogen receptor-β (ER-β) selectivity that imparts weak anti-proliferative activity against prostate cancer cells. DL-2-[4-(2-piperidinoethoxy)phenyl]-3-phenyl-2H-1-benzopyran (BP), a SERM designed with benzopyran core, targeted androgen independent prostate cancer (PC-3) cells 14-times more potently than genistein, ~ 25% more efficiently than tamoxifen and 6.5-times more actively than ICI-182780, without forfeiting significant specificity in comparison to genistein. BP increased apoptosis (annexin-V and TUNEL labeling), arrested cell cycle, and significantly increased caspase-3 activity along with mRNA expressions of estrogen receptor (ER)-β and FasLmore » (qPCR) in PC-3 cells. In classical ERE-luc reporter assay BP behaved as a potent ER-α antagonist and ER-β agonist. Accordingly, it decreased expression of ER-α target PS2 (P < 0.01) and increased expression of ER-β target TNF-α (P < 0.05) genes in PC-3. ER-β deficient PC-3 (siRNA-transfected) was resistant to apoptotic and anti-proliferative actions of SERMs, including stimulation of FasL expression by BP. BP significantly inhibited phosphorylation of Akt and ERK-1/2, JNK and p38 in PC-3 (immunoblotting), and thus adopted a multi-pathway mechanism to exert a more potent anti-proliferative activity against prostate cancer cells than natural and synthetic SERMs. Its precise ER-subtype specific activity presents a unique lead structure for further optimization. - Highlights: • BP with benzopyran core of genistein was identified for ER-β selective action. • BP was 14-times more potent than genistien in targeting prostate cancer cells. • It behaved as a potent ER-β agonist and ER-α antagonist in gene reporter assays. • BP's anti-proliferative action was inhibited significantly in ER-β deficient cells. • BP — a unique lead structure for further optimization.« less

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.

Synthesis, biological and antitumor activity of a highly potent 6-substituted pyrrolo[2,3-d]pyrimidine thienoyl antifolate inhibitor with proton-coupled folate transporter and folate receptor selectivity over the reduced folate carrier that inhibits β-glycinamide ribonucleotide formyltransferase

PubMed Central

Wang, Lei; Desmoulin, Sita Kugel; Cherian, Christina; Polin, Lisa; White, Kathryn; Kushner, Juiwanna; Fulterer, Andreas; Chang, Min-Hwang; Mitchell, Shermaine; Stout, Mark; Romero, Michael F.; Hou, Zhanjun; Matherly, Larry H.; Gangjee, Aleem

2011-01-01

2-Amino-4-oxo-6-substituted pyrrolo[2,3-d]pyrimidine antifolates with a thienoyl side chain (compounds 1–3, respectively) were synthesized for comparison with compound 4, the previous lead compound of this series. Conversion of hydroxyl acetylen-thiophene carboxylic esters to thiophenyl-α-bromomethylketones and condensation with 2,4-diamino-6-hydroxypyrimidine afforded the 6-substituted pyrrolo[2,3-d]pyrimidine compounds of type 18 and 19. Coupling with L-glutamate diethyl ester, followed by saponification, afforded 1–3. Compound 3 selectively inhibited proliferation of cells expressing folate receptors (FRs) α or β, or the proton-coupled folate transporter (PCFT), including human tumor cells KB and IGROV1 much more potently than 4. Compound 3 was more inhibitory than 4 toward β-glycinamide ribonucleotide formyltransferase (GARFTase). Both 3 and 4 depleted cellular ATP pools. In SCID mice with IGROV1 tumors, 3 was more efficacious than 4. Collectively, our results show potent antitumor activity for 3 in vitro and in vivo, associated with its selective membrane transport by FRs and PCFT over RFC and inhibition of GARFTase, clearly establishing the 3-atom bridge as superior to the 1, 2 and 4-atom bridge lengths for the activity of this series. PMID:21879757

Anticoagulant and antithrombotic evaluation of native fucosylated chondroitin sulfates and their derivatives as selective inhibitors of intrinsic factor Xase.

PubMed

Wu, Mingyi; Wen, Dandan; Gao, Na; Xiao, Chuang; Yang, Lian; Xu, Li; Lian, Wu; Peng, Wenlie; Jiang, Jianmin; Zhao, Jinhua

2015-03-06

Fucosylated chondroitin sulfate (FCS), a structurally unusual glycosaminoglycan, has distinct anticoagulant properties, and is an especially strong inhibitor of the intrinsic factor Xase (anti-Xase). To obtain a highly selective inhibitor of human Xase, we purified six native FCSs with various sulfation patterns, prepared a series of FCS derivatives, and then elucidated the relationship between the structures and the anticoagulant activities of FCSs. FCSs 1-3 containing higher Fuc2S4S exhibit stronger AT-dependent anti-IIa activities, whereas 4-6 containing more Fuc3S4S produce potent HCII-dependent anti-IIa activities. Saccharides containing a minimum of 6-8 trisaccharide units, free carboxyl groups, and full fucosylation of GlcA may be required for potent anti-Xase activity, and approximately six trisaccharide units and partial fucosylation of GlcA may contribute to potent HCII-dependent activity. Decreasing of the molecular weights markedly reduces their AT-dependent anti-IIa activities, and even eliminates human platelet and factor XII activation. Furthermore, in vitro and in vivo studies suggested that fractions of 6-12 kDa may be very promising compounds as putative selective intrinsic Xase inhibitors with antithrombotic action, but without the consequences of major bleeding and factor XII activation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Construction and characterization of stable, constitutively expressed, chromosomal green and red fluorescent transcriptional fusions in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei

PubMed Central

Su, Shengchang; Bangar, Hansraj; Saldanha, Roland; Pemberton, Adin; Aronow, Bruce; Dean, Gary E; Lamkin, Thomas J; Hassett, Daniel J

2014-01-01

Here, we constructed stable, chromosomal, constitutively expressed, green and red fluorescent protein (GFP and RFP) as reporters in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei. Using bioinformatic approaches and other experimental analyses, we identified P0253 and P1 as potent promoters that drive the optimal expression of fluorescent reporters in single copy in B. anthracis and Burkholderia spp. as well as their surrogate strains, respectively. In comparison, Y. pestis and its surrogate strain need two chromosomal copies of cysZK promoter (P2cysZK) for optimal fluorescence. The P0253-, P2cysZK-, and P1-driven GFP and RFP fusions were first cloned into the vectors pRP1028, pUC18R6KT-mini-Tn7T-Km, pmini-Tn7-gat, or their derivatives. The resultant constructs were delivered into the respective surrogates and subsequently into the select agent strains. The chromosomal GFP- and RFP-tagged strains exhibited bright fluorescence at an exposure time of less than 200 msec and displayed the same virulence traits as their wild-type parental strains. The utility of the tagged strains was proven by the macrophage infection assays and lactate dehydrogenase release analysis. Such strains will be extremely useful in high-throughput screens for novel compounds that could either kill these organisms, or interfere with critical virulence processes in these important bioweapon agents and during infection of alveolar macrophages. PMID:25044501

Construction and characterization of stable, constitutively expressed, chromosomal green and red fluorescent transcriptional fusions in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei.

PubMed

Su, Shengchang; Bangar, Hansraj; Saldanha, Roland; Pemberton, Adin; Aronow, Bruce; Dean, Gary E; Lamkin, Thomas J; Hassett, Daniel J

2014-10-01

Here, we constructed stable, chromosomal, constitutively expressed, green and red fluorescent protein (GFP and RFP) as reporters in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei. Using bioinformatic approaches and other experimental analyses, we identified P0253 and P1 as potent promoters that drive the optimal expression of fluorescent reporters in single copy in B. anthracis and Burkholderia spp. as well as their surrogate strains, respectively. In comparison, Y. pestis and its surrogate strain need two chromosomal copies of cysZK promoter (P2cysZK) for optimal fluorescence. The P0253-, P2cysZK-, and P1-driven GFP and RFP fusions were first cloned into the vectors pRP1028, pUC18R6KT-mini-Tn7T-Km, pmini-Tn7-gat, or their derivatives. The resultant constructs were delivered into the respective surrogates and subsequently into the select agent strains. The chromosomal GFP- and RFP-tagged strains exhibited bright fluorescence at an exposure time of less than 200 msec and displayed the same virulence traits as their wild-type parental strains. The utility of the tagged strains was proven by the macrophage infection assays and lactate dehydrogenase release analysis. Such strains will be extremely useful in high-throughput screens for novel compounds that could either kill these organisms, or interfere with critical virulence processes in these important bioweapon agents and during infection of alveolar macrophages. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Neurophysiological Analysis of Circadian Rhythm Entrainment

DTIC Science & Technology

1994-05-24

on activations in response to the ionotropic agonist NMDA (25). These results point to a previously uninvestigated role for metabotropic receptors in...are selective agonists of the metabotropic type of glutamate receptor . Selective metabotropic antagonists can block these effects but do not alter...glutamate receptors on SCN cell activity. In slice preparations, our initial findings are that the selective metabotropic agonist 1S,3R-ACPD has very potent

Design, synthesis and biological evaluation of piperazinyl-β-carbolinederivatives as anti-leishmanial agents.

PubMed

Ashok, Penta; Chander, Subhash; Smith, Terry K; Sankaranarayanan, Murugesan

2018-04-25

Molecular hybridization is a ligand based drug design approach is well known recent medicinal chemistry to design anti-parasitic agents. In the present study, we have designed a series of (1-phenyl-9H-pyrido [3,4-b]indol-3-yl) (4-phenylpiperazin-1-yl)methanone derivatives using molecular hybridization approach. Designed analogues were evaluated for cytotoxicity and inhibition activity against Leishmania infantum and Leishmania donovani. Among these reported analogues 7b, 7d, 7e, 7f and 7m displayed potent inhibition of both L. infantum and L. donovani. Compounds 7i and 7k exhibited selective potent inhibition of L. donovani. Especially, compounds 7e and 7k showed most potent anti-leishmanial activity against L. infantum and L. donovani respectively. Anti-leishmanial activity of these compounds is comparable with standard drugs miltefosine and pentamidine. SAR studies revealed that, electron donating group substitution on phenyl ring recommended for potent anti-leishmanial activity. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A tribute to Dr. Paul A. J. Janssen: entrepreneur extraordinaire, innovative scientist, and significant contributor to anesthesiology.

PubMed

Stanley, Theodore H; Egan, Talmage D; Van Aken, Hugo

2008-02-01

Dr. Paul Janssen was the founder of Janssen Pharmaceutica and the developer of over 80 pharmaceutical compounds that proved useful in human, botanical, and veterinary medicine. He and his coworkers synthesized the fentanyl family of drugs, many other potent analgesics, droperidol, etomidate, and numerous other important medicines that were extremely useful in psychiatry, parasitology, gastroenterology, cardiology, virology, and immunology. Anesthesiology and medicine as a whole have benefited a great deal from his resourcefulness, creativity, and entrepreneurial spirit.

Molecular recognition at adenine nucleotide (P2) receptors in platelets.

PubMed

Jacobson, Kenneth A; Mamedova, Liaman; Joshi, Bhalchandra V; Besada, Pedro; Costanzi, Stefano

2005-04-01

Transmembrane signaling through P2Y receptors for extracellular nucleotides controls a diverse array of cellular processes, including thrombosis. Selective agonists and antagonists of the two P2Y receptors present on the platelet surface-the G (q)-coupled P2Y (1) subtype and the G (i)-coupled P2Y (12) subtype-are now known. High-affinity antagonists of each have been developed from nucleotide structures. The (N)-methanocarba bisphosphate derivatives MRS2279 and MRS2500 are potent and selective P2Y (1) receptor antagonists. The carbocyclic nucleoside AZD6140 is an uncharged, orally active P2Y (12) receptor antagonist of nM affinity. Another nucleotide receptor on the platelet surface, the P2X (1) receptor, the activation of which may also be proaggregatory, especially under conditions of high shear stress, has high-affinity ligands, although high selectivity has not yet been achieved. Although alpha,beta-methylene-adenosine triphosphate (ATP) is the classic agonist for the P2X (1) receptor, where it causes rapid desensitization, the agonist BzATP is among the most potent in activating this subtype. The aromatic sulfonates NF279 and NF449 are potent antagonists of the P2X (1) receptor. The structures of the two platelet P2Y receptors have been modeled, based on a rhodopsin template, to explain the basis for nucleotide recognition within the putative transmembrane binding sites. The P2Y (1) receptor model, especially, has been exploited in the design and optimization of antagonists targeted to interact selectively with that subtype.

Design, Synthesis and Biological Evaluation of4-(Imidazolylmethyl)-2-(4-methylsulfonyl phenyl)-Quinoline Derivatives as Selective COX-2 Inhibitors and In-vitro Anti-breast Cancer Agents

PubMed Central

Ghodsi, Razieh; Azizi, Ebrahim; Zarghi, Afshin

2016-01-01

A new group of 4-(Imidazolylmethyl)quinoline derivatives possessing a methylsulfonyl COX-2 pharmacophore at the para position of the C-2 phenyl ring were designed and synthesized as selective COX-2 inhibitors and in-vitroanti breast cancer agents. In-vitro COX-1 and COX-2 inhibition studies showed that all the compounds were potent and selective inhibitors of the COX-2 isozyme with IC50 values in the potent range 0.063-0.090 µM, and COX-2 selectivity indexes in the 179.9 to 547.6 range. Molecular modeling studies indicated that the methylsulfonyl substituent can be inserted into the secondary pocket of COX-2 active site for interactions with Arg513. Cytotoxicity of quinolines 9a-e against human breast cancer MCF-7 and T47D cell lines were also evaluated. All the compounds 9a-e were more cytotoxic against MCF-7 cells in comparison with those of T47D which express aromatase mRNA less than MCF-7 cells.The data showed that the increase of lipophilic properties of substituents on the C-7 and C-8 quinoline ring increased their cytotoxicity on MCF-7cells andCOX-2 inhibitory activity. Among the quinolines 9a-e, 4-((1H-Imidazol-1-yl)methyl) 7,8,9,10-tetrahydro-2-(4-methylsulfonylphenyl)-benzo[h]quinoline (9d)was identified as the most potent andselective COX-2inhibitor as well as the most cytotoxic agent against MCF-7 cells. PMID:27610157

Innovative computer-aided methods for the discovery of new kinase ligands.

PubMed

Abuhammad, Areej; Taha, Mutasem

2016-04-01

Recent evidence points to significant roles played by protein kinases in cell signaling and cellular proliferation. Faulty protein kinases are involved in cancer, diabetes and chronic inflammation. Efforts are continuously carried out to discover new inhibitors for selected protein kinases. In this review, we discuss two new computer-aided methodologies we developed to mine virtual databases for new bioactive compounds. One method is ligand-based exploration of the pharmacophoric space of inhibitors of any particular biotarget followed by quantitative structure-activity relationship-based selection of the best pharmacophore(s). The second approach is structure-based assuming that potent ligands come into contact with binding site spots distinct from those contacted by weakly potent ligands. Both approaches yield pharmacophores useful as 3D search queries for the discovery of new bioactive (kinase) inhibitors.

Differentiation of muscarinic cholinergic receptor subtypes in human cortex and pons - Implications for anti-motion sickness therapy

NASA Technical Reports Server (NTRS)

Mccarthy, Bruce G.; Peroutka, Stephen J.

1988-01-01

Radioligand binding studies were used to analyze muscarinic cholinergic receptor subtypes in human cortex and pons. Muscarinic cholinergic receptors were labeled by H-3-quinuclidinyl benzilate (H-3-QNB). Scopolamine was equipotent in both brain regions and did not discriminate subtypes of H-3-QNB binding. By contrast, the M1 selective antagonist pirenzepine was approximately 33-fold more potent in human cortex than pons. Carbachol, a putative M2 selective agonist, was more than 100-fold more potent in human pons than cortex. These results demonstrate that the human pons contains a relatively large proportion of carbachol-sensitive muscarinic cholinergic receptors. Drugs targeted to this subpopulation of muscarinic cholinergic receptors may prove to be effective anti-motion sickness agents with less side effects than scopolamine.

Heterocyclic periphery in the design of carbonic anhydrase inhibitors: 1,2,4-Oxadiazol-5-yl benzenesulfonamides as potent and selective inhibitors of cytosolic hCA II and membrane-bound hCA IX isoforms.

PubMed

Krasavin, Mikhail; Shetnev, Anton; Sharonova, Tatyana; Baykov, Sergey; Tuccinardi, Tiziano; Kalinin, Stanislav; Angeli, Andrea; Supuran, Claudiu T

2018-02-01

A series of novel aromatic primary sulfonamides decorated with diversely substituted 1,2,4-oxadiazole periphery groups has been prepared using a parallel chemistry approach. The compounds displayed a potent inhibition of cytosolic hCA II and membrane-bound hCA IX isoforms. Due to a different cellular localization of the two target enzymes, the compounds can be viewed as selective inhibition tools for either isoform, depending on the cellular permeability profile. The SAR findings revealed in this study has been well rationalized by docking simulation of the key compounds against the crystal structures of the relevant hCA isoforms. Copyright © 2017. Published by Elsevier Inc.

A small molecule inhibitor of Rheb selectively targets mTORC1 signaling.

PubMed

Mahoney, Sarah J; Narayan, Sridhar; Molz, Lisa; Berstler, Lauren A; Kang, Seong A; Vlasuk, George P; Saiah, Eddine

2018-02-07

The small G-protein Rheb activates the mechanistic target of rapamycin complex 1 (mTORC1) in response to growth factor signals. mTORC1 is a master regulator of cellular growth and metabolism; aberrant mTORC1 signaling is associated with fibrotic, metabolic, and neurodegenerative diseases, cancers, and rare disorders. Point mutations in the Rheb switch II domain impair its ability to activate mTORC1. Here, we report the discovery of a small molecule (NR1) that binds Rheb in the switch II domain and selectively blocks mTORC1 signaling. NR1 potently inhibits mTORC1 driven phosphorylation of ribosomal protein S6 kinase beta-1 (S6K1) but does not inhibit phosphorylation of AKT or ERK. In contrast to rapamycin, NR1 does not cause inhibition of mTORC2 upon prolonged treatment. Furthermore, NR1 potently and selectively inhibits mTORC1 in mouse kidney and muscle in vivo. The data presented herein suggest that pharmacological inhibition of Rheb is an effective approach for selective inhibition of mTORC1 with therapeutic potential.

Runaway cultural niche construction

PubMed Central

Rendell, Luke; Fogarty, Laurel; Laland, Kevin N.

2011-01-01

Cultural niche construction is a uniquely potent source of selection on human populations, and a major cause of recent human evolution. Previous theoretical analyses have not, however, explored the local effects of cultural niche construction. Here, we use spatially explicit coevolutionary models to investigate how cultural processes could drive selection on human genes by modifying local resources. We show that cultural learning, expressed in local niche construction, can trigger a process with dynamics that resemble runaway sexual selection. Under a broad range of conditions, cultural niche-constructing practices generate selection for gene-based traits and hitchhike to fixation through the build up of statistical associations between practice and trait. This process can occur even when the cultural practice is costly, or is subject to counteracting transmission biases, or the genetic trait is selected against. Under some conditions a secondary hitchhiking occurs, through which genetic variants that enhance the capability for cultural learning are also favoured by similar dynamics. We suggest that runaway cultural niche construction could have played an important role in human evolution, helping to explain why humans are simultaneously the species with the largest relative brain size, the most potent capacity for niche construction and the greatest reliance on culture. PMID:21320897

3-Coumaranone derivatives as inhibitors of monoamine oxidase.

PubMed

Van Dyk, Adriaan S; Petzer, Jacobus P; Petzer, Anél; Legoabe, Lesetja J

2015-01-01

The present study examines the monoamine oxidase (MAO) inhibitory properties of a series of 20 3-coumaranone [benzofuran-3(2H)-one] derivatives. The 3-coumaranone derivatives are structurally related to series of α-tetralone and 1-indanone derivatives, which have recently been shown to potently inhibit MAO, with selectivity for MAO-B (in preference to the MAO-A isoform). 3-Coumaranones are similarly found to selectively inhibit human MAO-B with half-maximal inhibitory concentration (IC50) values of 0.004-1.05 µM. Nine compounds exhibited IC50<0.05 µM for the inhibition of MAO-B. For the inhibition of human MAO-A, IC50 values ranged from 0.586 to >100 µM, with only one compound possessing an IC50<1 µM. For selected 3-coumaranone derivatives, it is established that MAO-A and MAO-B inhibition are reversible since dialysis of enzyme-inhibitor mixtures almost completely restores enzyme activity. On the basis of the selectivity profiles and potent action, it may be concluded that the 3-coumaranone derivatives are suitable leads for the development of selective MAO-B inhibitors as potential treatment for disorders such as Parkinson's disease and Alzheimer's disease.

3-Coumaranone derivatives as inhibitors of monoamine oxidase

PubMed Central

Van Dyk, Adriaan S; Petzer, Jacobus P; Petzer, Anél; Legoabe, Lesetja J

2015-01-01

The present study examines the monoamine oxidase (MAO) inhibitory properties of a series of 20 3-coumaranone [benzofuran-3(2H)-one] derivatives. The 3-coumaranone derivatives are structurally related to series of α-tetralone and 1-indanone derivatives, which have recently been shown to potently inhibit MAO, with selectivity for MAO-B (in preference to the MAO-A isoform). 3-Coumaranones are similarly found to selectively inhibit human MAO-B with half-maximal inhibitory concentration (IC50) values of 0.004–1.05 µM. Nine compounds exhibited IC50<0.05 µM for the inhibition of MAO-B. For the inhibition of human MAO-A, IC50 values ranged from 0.586 to >100 µM, with only one compound possessing an IC50<1 µM. For selected 3-coumaranone derivatives, it is established that MAO-A and MAO-B inhibition are reversible since dialysis of enzyme–inhibitor mixtures almost completely restores enzyme activity. On the basis of the selectivity profiles and potent action, it may be concluded that the 3-coumaranone derivatives are suitable leads for the development of selective MAO-B inhibitors as potential treatment for disorders such as Parkinson’s disease and Alzheimer’s disease. PMID:26491258

Grassystatins A–C from Marine Cyanobacteria, Potent Cathepsin E Inhibitors that Reduce Antigen Presentation

PubMed Central

Kwan, Jason C.; Eksioglu, Erika A.; Liu, Chen; Paul, Valerie J.; Luesch, Hendrik

2009-01-01

In our efforts to explore marine cyanobacteria as a source of novel bioactive compounds we discovered a statine unit-containing linear decadepsipeptide, grassystatin A (1), which we screened against a diverse set of 59 proteases. We describe the structure determination of 1 and two natural analogs, grassystatins B (2) and C (3), using NMR, MS, and chiral HPLC techniques. Compound 1 selectively inhibited cathepsins D and E with IC50s of 26.5 nM and 886 pM, respectively. Compound 2 showed similar potency and selectivity against cathepsins D and E (IC50s 7.27 nM and 354 pM, respectively), whereas the truncated peptide analog grassystatin C (3), which consists of two fewer residues than 1 and 2, was less potent against both but still selective for cathepsin E. The selectivity of compounds 1–3 for cathepsin E over D (20- to 38-fold) suggests that these natural products may be useful tools to probe cathepsin E function. We investigated the structural basis of this selectivity using molecular docking. We also show that 1 can reduce antigen presentation by dendritic cells, a process thought to rely on cathepsin E. PMID:19715320

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.

Design of novel neurokinin 1 receptor antagonists based on conformationally constrained aromatic amino acids and discovery of a potent chimeric opioid agonist-neurokinin 1 receptor antagonist.

PubMed

Ballet, Steven; Feytens, Debby; Buysse, Koen; Chung, Nga N; Lemieux, Carole; Tumati, Suneeta; Keresztes, Attila; Van Duppen, Joost; Lai, Josephine; Varga, Eva; Porreca, Frank; Schiller, Peter W; Vanden Broeck, Jozef; Tourwé, Dirk

2011-04-14

A screening of conformationally constrained aromatic amino acids as base cores for the preparation of new NK1 receptor antagonists resulted in the discovery of three new NK1 receptor antagonists, 19 [Ac-Aba-Gly-NH-3',5'-(CF(3))(2)-Bn], 20 [Ac-Aba-Gly-NMe-3',5'-(CF(3))(2)-Bn], and 23 [Ac-Tic-NMe-3',5'-(CF(3))(2)-Bn], which were able to counteract the agonist effect of substance P, the endogenous ligand of NK1R. The most active NK1 antagonist of the series, 20 [Ac-Aba-Gly-NMe-3',5'-(CF(3))(2)-Bn], was then used in the design of a novel, potent chimeric opioid agonist-NK1 receptor antagonist, 35 [Dmt-D-Arg-Aba-Gly-NMe-3',5'-(CF(3))(2)-Bn], which combines the N terminus of the established Dmt(1)-DALDA agonist opioid pharmacophore (H-Dmt-D-Arg-Phe-Lys-NH(2)) and 20, the NK1R ligand. The opioid component of the chimeric compound 35, that is, Dmt-D-Arg-Aba-Gly-NH(2) (36), also proved to be an extremely potent and balanced μ and δ opioid receptor agonist with subnanomolar binding and in vitro functional activity.

Broad and potent HIV-1 neutralization by a human antibody that binds the gp41-gp120 interface

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

Huang, Jinghe; Kang, Byong H.; Pancera, Marie

The isolation of human monoclonal antibodies is providing important insights into the specificities that underlie broad neutralization of HIV-1 (reviewed in ref. 1). Here we report a broad and extremely potent HIV-specific monoclonal antibody, termed 35O22, which binds a novel HIV-1 envelope glycoprotein (Env) epitope. 35O22 neutralized 62% of 181 pseudoviruses with a half-maximum inhibitory concentration (IC 50) <50 μg ml -1. The median IC 50 of neutralized viruses was 0.033 μg ml -1, among the most potent thus far described. 35O22 did not bind monomeric forms of Env tested, but did bind the trimeric BG505 SOSIP.664. Mutagenesis and amore » reconstruction by negative-stain electron microscopy of the Fab in complex with trimer revealed that it bound to a conserved epitope, which stretched across gp120 and gp41. The specificity of 35O22 represents a novel site of vulnerability on HIV Env, which serum analysis indicates to be commonly elicited by natural infection. Binding to this new site of vulnerability may thus be an important complement to current monoclonal-antibody-based approaches to immunotherapies, prophylaxis and vaccine design.« less

Multipotent cholinesterase/monoamine oxidase inhibitors for the treatment of Alzheimer's disease: design, synthesis, biochemical evaluation, ADMET, molecular modeling, and QSAR analysis of novel donepezil-pyridyl hybrids.

PubMed

Bautista-Aguilera, Oscar M; Esteban, Gerard; Chioua, Mourad; Nikolic, Katarina; Agbaba, Danica; Moraleda, Ignacio; Iriepa, Isabel; Soriano, Elena; Samadi, Abdelouahid; Unzeta, Mercedes; Marco-Contelles, José

2014-01-01

The design, synthesis, and biochemical evaluation of donepezil-pyridyl hybrids (DPHs) as multipotent cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors for the potential treatment of Alzheimer's disease (AD) is reported. The 3D-quantitative structure-activity relationship study was used to define 3D-pharmacophores for inhibition of MAO A/B, acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) enzymes and to design DPHs as novel multi-target drug candidates with potential impact in the therapy of AD. DPH14 (Electrophorus electricus AChE [EeAChE]: half maximal inhibitory concentration [IC50] =1.1±0.3 nM; equine butyrylcholinesterase [eqBuChE]: IC50 =600±80 nM) was 318-fold more potent for the inhibition of AChE, and 1.3-fold less potent for the inhibition of BuChE than the reference compound ASS234. DPH14 is a potent human recombinant BuChE (hBuChE) inhibitor, in the same range as DPH12 or DPH16, but 13.1-fold less potent than DPH15 for the inhibition of human recombinant AChE (hAChE). Compared with donepezil, DPH14 is almost equipotent for the inhibition of hAChE, and 8.8-fold more potent for hBuChE. Concerning human monoamine oxidase (hMAO) A inhibition, only DPH9 and 5 proved active, compound DPH9 being the most potent (IC50 [MAO A] =5,700±2,100 nM). For hMAO B, only DPHs 13 and 14 were moderate inhibitors, and compound DPH14 was the most potent (IC50 [MAO B] =3,950±940 nM). Molecular modeling of inhibitor DPH14 within EeAChE showed a binding mode with an extended conformation, interacting simultaneously with both catalytic and peripheral sites of EeAChE thanks to a linker of appropriate length. Absortion, distribution, metabolism, excretion and toxicity analysis showed that structures lacking phenyl-substituent show better druglikeness profiles; in particular, DPHs13-15 showed the most suitable absortion, distribution, metabolism, excretion and toxicity properties. Novel donepezil-pyridyl hybrid DPH14 is a potent, moderately selective hAChE and selective irreversible hMAO B inhibitor which might be considered as a promising compound for further development for the treatment of AD.

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.

5-Amino-6-chloro-N-[(1-isobutylpiperidin-4-yl)methyl]-2-methylimidazo[1,2-alpha]pyridine-8-carboxamide (CJ-033,466), a novel and selective 5-hydroxytryptamine4 receptor partial agonist: pharmacological profile in vitro and gastroprokinetic effect in conscious dogs.

PubMed

Mikami, Tadayoshi; Ochi, Yasuo; Suzuki, Keiko; Saito, Toshiyuki; Sugie, Yutaka; Sakakibara, Minoru

2008-04-01

5-Hydroxytryptamine (5-HT) receptors and dopamine(2) (D(2)) receptor modulate gastrointestinal motility. Gastroprokinetic agents that act on several 5-HT receptor subtypes and/or D(2) receptors are used clinically. Although the 5-HT(4) receptor is known to mediate the gastroprokinetic effects of these agents, the absence of highly selective 5-HT(4) receptor agonists has made it difficult to confirm the physiological consequences of selective 5-HT(4) receptor stimulation. In this study, we report the in vitro pharmacological profiles and the in vivo gastroprokinetic effects of 5-amino-6-chloro-N-[(1-isobutylpiperidin-4-yl)methyl]-2-methylimidazo[1,2-alpha]pyridine-8-carboxamide (CJ-033,466), a novel, potent, and selective 5-HT(4) partial agonist. Compared with preceding 5-HT(4) agonists such as cisapride, mosapride, and tegaserod, CJ-033,466 had a superior in vitro profile, with nanomolar agonistic activities for the 5-HT(4) receptor and 1000-fold greater selectivity for the 5-HT(4) receptor over other 5-HT and D(2) receptors. In vivo studies in conscious dogs showed that CJ-033,466 dose-dependently stimulated gastric antral motility in both the fasted and postprandial states at the same dose range and that it was 30 times more potent than cisapride. Furthermore, CJ-033,466 accelerated the gastric emptying rate in a gastroparesis dog model at the minimally effective dose established in the gastric motility study. In conclusion, CJ-033,466 is a potent and highly selective 5-HT(4) agonist that stimulates physiologically coordinated gastric motility, and it has no activity on other 5-HT receptor subtypes and D(2) receptors. Therefore, CJ-033,466 could be used to treat gastroparesis, providing better gastroprokinetics and reduced side effects mediated by the other receptors.

Synthesis of potent agonists of substance P by replacement of Met11 with Glu(OBzl) and N-terminal glutamine with Glp of the C-terminal hexapeptide and heptapeptide of substance P.

PubMed

Stavropoulos, G; Karagiannis, K; Anagnostides, S; Ministrouski, I; Selinger, Z; Chorev, M

1995-06-01

The analogues [Glp6,Glu(OBzl)11]SP(6-11) and [Glp5,Glu(OBzl)11]SP(5-11) of the C-terminal hexapeptide and heptapeptide of Substance P have been synthesized by conventional solution methods. In each analogue the N-terminal glutamine has been replaced by pyroglutamic acid, while the COOCH2C6H5 ester group has replaced the SCH3 group of the Met11 side chain. The in vitro activity of both analogues has been determined on three biological preparations: guinea pig ileum (GPI), rat vas deferens (RVD) and rat portal vein (RPV). The results showed that both analogues are highly potent and selective agonists on GPI through the NK-1 receptor. They are more potent than SP itself, with 1.54 and 1.25 respective values of relative potency on GPI. Their selectivity has been studied by utilizing atropine-treated guinea pig ileum (GPI+At). The analogues showed low activity on RVD and RPV tissues, which represent NK-2 and NK-3 monoreceptor assay, respectively.

Structural insights into human heme oxygenase-1 inhibition by potent and selective azole-based compounds

PubMed Central

Rahman, Mona N.; Vukomanovic, Dragic; Vlahakis, Jason Z.; Szarek, Walter A.; Nakatsu, Kanji; Jia, Zongchao

2013-01-01

The development of heme oxygenase (HO) inhibitors, especially those that are isozyme-selective, promises powerful pharmacological tools to elucidate the regulatory characteristics of the HO system. It is already known that HO has cytoprotective properties and may play a role in several disease states, making it an enticing therapeutic target. Traditionally, the metalloporphyrins have been used as competitive HO inhibitors owing to their structural similarity with the substrate, heme. However, given heme's important role in several other proteins (e.g. cytochromes P450, nitric oxide synthase), non-selectivity is an unfortunate side-effect. Reports that azalanstat and other non-porphyrin molecules inhibited HO led to a multi-faceted effort to develop novel compounds as potent, selective inhibitors of HO. This resulted in the creation of non-competitive inhibitors with selectivity for HO, including a subset with isozyme selectivity for HO-1. Using X-ray crystallography, the structures of several complexes of HO-1 with novel inhibitors have been elucidated, which provided insightful information regarding the salient features required for inhibitor binding. This included the structural basis for non-competitive inhibition, flexibility and adaptability of the inhibitor binding pocket, and multiple, potential interaction subsites, all of which can be exploited in future drug-design strategies. PMID:23097500

Synergism of virtual screening and medicinal chemistry: identification and optimization of allosteric antagonists of metabotropic glutamate receptor 1.

PubMed

Noeske, Tobias; Trifanova, Dina; Kauss, Valerjans; Renner, Steffen; Parsons, Christopher G; Schneider, Gisbert; Weil, Tanja

2009-08-01

We report the identification of novel potent and selective metabotropic glutamate receptor 1 (mGluR1) antagonists by virtual screening and subsequent hit optimization. For ligand-based virtual screening, molecules were represented by a topological pharmacophore descriptor (CATS-2D) and clustered by a self-organizing map (SOM). The most promising compounds were tested in mGluR1 functional and binding assays. We identified a potent chemotype exhibiting selective antagonistic activity at mGluR1 (functional IC(50)=0.74+/-0.29 microM). Hit optimization yielded lead structure 16 with an affinity of K(i)=0.024+/-0.001 microM and greater than 1000-fold selectivity for mGluR1 versus mGluR5. Homology-based receptor modelling suggests a binding site compatible with previously reported mutation studies. Our study demonstrates the usefulness of ligand-based virtual screening for scaffold-hopping and rapid lead structure identification in early drug discovery projects.

Bis-Cyclic-Guanidine as a Novel Class of Compounds Potent Against Clostridium Difficile.

PubMed

Li, Chunhui; Teng, Peng; Peng, Zhong; Sang, Peng; Sun, Xingmin; Cai, Jianfeng

2018-05-16

Clostridium difficile infection (CDI) symptoms range from diarrhea to severe toxic megacolon and even death. Due to its rapid acquisition of resistance, C. difficile is listed as an urgent antibiotic-resistant threat, and has surpassed methicillin-resistant Staphylococcus aureus (MRSA) as the most common hospital-acquired infections in the USA. To combat the pathogen, the new structural class of pseudo peptides that exhibit antimicrobial activities could play an important role. Herein, we report that bis-cyclic guanidine compounds that exhibit potent antibacterial activity against C. difficile with decent selectivity. Eight compounds showed high in vitro potency against C. difficile UK6 with MIC of 1.0 μg/mL, and cytotoxic selectivity index (SI) up to 37. Moreover, the most selective compound 13 is also effective upon the treatment of C. difficile-induced diseases in the mouse model of CDI, and appears to be a very promising new candidate for the treatment of CDI. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Discovery of OSI-906: a selective and orally efficacious dual inhibitor of the IGF-1 receptor and insulin receptor.

PubMed

Mulvihill, Mark J; Cooke, Andrew; Rosenfeld-Franklin, Maryland; Buck, Elizabeth; Foreman, Ken; Landfair, Darla; O'Connor, Matthew; Pirritt, Caroline; Sun, Yingchaun; Yao, Yan; Arnold, Lee D; Gibson, Neil W; Ji, Qun-Sheng

2009-09-01

The IGF-1 receptor (IGF-1R) has been implicated in the promotion of tumorigenesis, metastasis and resistance to cancer therapies. Therefore, this receptor has become a major focus for the development of anticancer agents. Our lead optimization efforts that blended structure-based design and empirical medicinal chemistry led to the discovery of OSI-906, a novel small-molecule dual IGF-1R/insulin receptor (IR) kinase inhibitor. OSI-906 potently and selectively inhibits autophosphorylation of both human IGF-1R and IR, displays in vitro antiproliferative effects in a variety of tumor cell lines and shows robust in vivo anti-tumor efficacy in an IGF-1R-driven xenograft model when administered orally once daily. OSI-906 is a novel, potent, selective and orally bioavailable dual IGF-1R/IR kinase inhibitor with favorable preclinical drug-like properties, which has demonstrated in vivo efficacy in tumor models and is currently in clinical testing.

Selective and potent urea inhibitors of Cryptosporidium parvum inosine 5′ monophosphate dehydrogenase

PubMed Central

Gorla, Suresh Kumar; Kavitha, Mandapati; Zhang, Minjia; Liu, Xiaoping; Sharling, Lisa; Gollapalli, Deviprasad R.; Striepen, Boris; Hedstrom, Lizbeth; Cuny, Gregory D.

2012-01-01

Cryptosporidium parvum and related species are zoonotic intracellular parasites of the intestine. Cryptosporidium is a leading cause of diarrhea in small children around the world. Infection can cause severe pathology in children and immunocompromised patients. This waterborne parasite is resistant to common methods of water treatment and therefore a prominent threat to drinking and recreation water even in countries with strong water safety systems. The drugs currently used to combat these organisms are ineffective. Genomic analysis revealed that the parasite relies solely on inosine-5′-monophosphate dehydrogenase (IMPDH) for the biosynthesis of guanine nucleotides. Herein, we report a selective urea-based inhibitor of C. parvum IMPDH (CpIMPDH) identified by high throughput screening. We performed a SAR study of these inhibitors with some analogues exhibiting high potency (IC50 < 2 nM) against CpIMPDH, excellent selectivity > 1000-fold versus human IMPDH type 2 and good stability in mouse liver microsomes. A subset of inhibitors also displayed potent antiparasitic activity in a Toxoplasma gondii model. PMID:22950983

Discovery of Imidazoquinolines as a Novel Class of Potent, Selective, and in Vivo Efficacious Cancer Osaka Thyroid (COT) Kinase Inhibitors.

PubMed

Glatthar, Ralf; Stojanovic, Aleksandar; Troxler, Thomas; Mattes, Henri; Möbitz, Henrik; Beerli, Rene; Blanz, Joachim; Gassmann, Ernst; Drückes, Peter; Fendrich, Gabriele; Gutmann, Sascha; Martiny-Baron, Georg; Spence, Fiona; Hornfeld, Jeff; Peel, John Edmonson; Sparrer, Helmut

2016-08-25

Cancer Osaka thyroid (COT) kinase is an important regulator of pro-inflammatory cytokines in macrophages. Thus, pharmacologic inhibition of COT should be a valid approach to therapeutically intervene in the pathogenesis of macrophage-driven inflammatory diseases such as rheumatoid arthritis. We report the discovery and chemical optimization of a novel series of COT kinase inhibitors, with unprecedented nanomolar potency for the inhibition of TNFα. Pharmacological profiling in vivo revealed a high metabolism of these compounds in rats which was demonstrated to be predominantly attributed to aldehyde oxidase. Due to the very low activity of hepatic AO in the dog, the selected candidate 32 displayed significant blood exposure in dogs which resulted in a clear prevention of inflammation-driven lameness. Taken together, the described compounds both potently and selectively inhibit COT kinase in primary human cells and ameliorate inflammatory pathologies in vivo, supporting the notion that COT is an appropriate therapeutic target for inflammatory diseases.

Bispecific small molecule-antibody conjugate targeting prostate cancer.

PubMed

Kim, Chan Hyuk; Axup, Jun Y; Lawson, Brian R; Yun, Hwayoung; Tardif, Virginie; Choi, Sei Hyun; Zhou, Quan; Dubrovska, Anna; Biroc, Sandra L; Marsden, Robin; Pinstaff, Jason; Smider, Vaughn V; Schultz, Peter G

2013-10-29

Bispecific antibodies, which simultaneously target CD3 on T cells and tumor-associated antigens to recruit cytotoxic T cells to cancer cells, are a promising new approach to the treatment of hormone-refractory prostate cancer. Here we report a site-specific, semisynthetic method for the production of bispecific antibody-like therapeutics in which a derivative of the prostate-specific membrane antigen-binding small molecule DUPA was selectively conjugated to a mutant αCD3 Fab containing the unnatural amino acid, p-acetylphenylalanine, at a defined site. Homogeneous conjugates were generated in excellent yields and had good solubility. The efficacy of the conjugate was optimized by modifying the linker structure, relative binding orientation, and stoichiometry of the ligand. The optimized conjugate showed potent and selective in vitro activity (EC50 ~ 100 pM), good serum half-life, and potent in vivo activity in prophylactic and treatment xenograft mouse models. This semisynthetic approach is likely to be applicable to the generation of additional bispecific agents using drug-like ligands selective for other cell-surface receptors.

Biaryls as potent, tunable dual neurokinin 1 receptor antagonists and serotonin transporter inhibitors.

PubMed

Degnan, Andrew P; Tora, George O; Han, Ying; Rajamani, Ramkumar; Bertekap, Robert; Krause, Rudolph; Davis, Carl D; Hu, Joanna; Morgan, Daniel; Taylor, Sarah J; Krause, Kelly; Li, Yu-Wen; Mattson, Gail; Cunningham, Melissa A; Taber, Matthew T; Lodge, Nicholas J; Bronson, Joanne J; Gillman, Kevin W; Macor, John E

2015-08-01

Depression is a serious illness that affects millions of patients. Current treatments are associated with a number of undesirable side effects. Neurokinin 1 receptor (NK1R) antagonists have recently been shown to potentiate the antidepressant effects of serotonin-selective reuptake inhibitors (SSRIs) in a number of animal models. Herein we describe the optimization of a biaryl chemotype to provide a series of potent dual NK1R antagonists/serotonin transporter (SERT) inhibitors. Through the choice of appropriate substituents, the SERT/NK1R ratio could be tuned to afford a range of target selectivity profiles. This effort culminated in the identification of an analog that demonstrated oral bioavailability, favorable brain uptake, and efficacy in the gerbil foot tap model. Ex vivo occupancy studies with compound 58 demonstrated the ability to maintain NK1 receptor saturation (>88% occupancy) while titrating the desired level of SERT occupancy (11-84%) via dose selection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and in vivo evaluation of phenethylpiperazine amides: selective 5-hydroxytryptamine(2A) receptor antagonists for the treatment of insomnia.

PubMed

Xiong, Yifeng; Ullman, Brett; Choi, Jin-Sun Karoline; Cherrier, Martin; Strah-Pleynet, Sonja; Decaire, Marc; Dosa, Peter I; Feichtinger, Konrad; Teegarden, Bradley R; Frazer, John M; Yoon, Woo H; Shan, Yun; Whelan, Kevin; Hauser, Erin K; Grottick, Andrew J; Semple, Graeme; Al-Shamma, Hussien

2010-08-12

Recent developments in sleep research suggest that antagonism of the serotonin 5-HT(2A) receptor may improve sleep maintenance insomnia. We herein report the discovery of a series of potent and selective serotonin 5-HT(2A) receptor antagonists based on a phenethylpiperazine amide core structure. When tested in a rat sleep pharmacology model, these compounds increased both sleep consolidation and deep sleep. Within this series of compounds, an improvement in the metabolic stability of early leads was achieved by introducing a carbonyl group into the phenethylpiperazine linker. Of note, compounds 14 and 27 exhibited potent 5-HT(2A) receptor binding affinity, high selectivity over the 5-HT(2C) receptor, favorable CNS partitioning, and good pharmacokinetic and early safety profiles. In vivo, these two compounds showed dose-dependent, statistically significant improvements on deep sleep (delta power) and sleep consolidation at doses as low as 0.1 mg/kg.

Discovery of Tetralones as Potent and Selective Inhibitors of Acyl-CoA:Diacylglycerol Acyltransferase 1.

PubMed

Cheung, Mui; Tangirala, Raghuram S; Bethi, Sridhar R; Joshi, Hemant V; Ariazi, Jennifer L; Tirunagaru, Vijaya G; Kumar, Sanjay

2018-02-08

Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) plays an important role in triglyceride synthesis and is a target of interest for the treatment of metabolic disorders. Herein we describe the structure-activity relationship of a novel tetralone series of DGAT1 inhibitors and our strategies for overcoming genotoxic liability of the anilines embedded in the chemical structures, leading to the discovery of a candidate compound, ( S )-2-(6-(5-(3-(3,4-difluorophenyl)ureido)pyrazin-2-yl)-1-oxo-2-(2,2,2-trifluoroethyl)-1,2,3,4-tetrahydronaphthalen-2-yl)acetic acid (GSK2973980A, 26d ). Compound 26d is a potent and selective DGAT1 inhibitor with excellent DMPK profiles and in vivo efficacy in a postprandial lipid excursion model in mice. Based on the overall biological and developability profiles and acceptable safety profiles in the 7-day toxicity studies in rats and dogs, compound 26d was selected as a candidate compound for further development in the treatment of metabolic disorders.

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.

A modified estimation distribution algorithm based on extreme elitism.

PubMed

Gao, Shujun; de Silva, Clarence W

2016-12-01

An existing estimation distribution algorithm (EDA) with univariate marginal Gaussian model was improved by designing and incorporating an extreme elitism selection method. This selection method highlighted the effect of a few top best solutions in the evolution and advanced EDA to form a primary evolution direction and obtain a fast convergence rate. Simultaneously, this selection can also keep the population diversity to make EDA avoid premature convergence. Then the modified EDA was tested by means of benchmark low-dimensional and high-dimensional optimization problems to illustrate the gains in using this extreme elitism selection. Besides, no-free-lunch theorem was implemented in the analysis of the effect of this new selection on EDAs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Synthetic chalcones as potential anti-inflammatory and cancer chemopreventive agents.

PubMed

Won, Shen-Jeu; Liu, Cheng-Tsung; Tsao, Lo-Ti; Weng, Jing-Ru; Ko, Horng-Huey; Wang, Jih-Pyang; Lin, Chun-Nan

2005-01-01

In an effort to develop potent anti-inflammatory and cancer chemopreventive agents, a series of chalcones were prepared by Claisen-Schmidt condensation of appropriate acetophenones with suitable aromatic aldehyde or prepared with appropriate dihydrochalcone reacted with appropriate alkyl bromide or prepared in one-pot procedure involving acetophenone and convenient aromatic aldehyde using ultrasonic agitation on basic alumina. The synthesized products were tested for their inhibitory effects on the activation of mast cells, neutrophils, macrophages, and microglial cells. The potent inhibitors of NO production in macrophages and microglial cells were further evaluated for their in vitro cytotoxic effects against several human cancer cell lines. 2'-Hydroxychalcones 1-3, and 2',5'-dihydroxychalcone 7 exhibited potent inhibitory effects on the release of beta-glucuronidase or lysozyme from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB). Two 2'-hydroxychalcones (1 and 3) showed potent inhibitory effects on superoxide anion generation in rat neutrophils in response to fMLP/CB. The previously reported chalcone, 5, 6, and 12, exhibited potent inhibitory effect on NO production in lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma)-activated N9 microglial cells or in LPS-activated RAW 264.7 macrophage-like cells. The potent inhibitors 5, 6, and 12 of NO production in macrophages or microglial cells revealed significant or marginal cytotoxic effects against several human cancer lines. Compound 12 manifested potent selective cytotoxicity against human MCF-7 cells and caused cell death by apoptosis. The present results demonstrated that 1-3, and 7 have anti-inflammatory effects and 5, 6, and 12 are potential anti-inflammatory and cancer chemopreventive agents.

Design and synthesis of paracaseolide A analogues as selective protein tyrosine phosphatase 1B inhibitors.

PubMed

Yin, Jian-Peng; Tang, Chun-Lan; Gao, Li-Xin; Ma, Wei-Ping; Li, Jing-Ya; Li, Ying; Li, Jia; Nan, Fa-Jun

2014-06-07

A series of structurally related analogues of the natural product paracaseolide A were synthesized and identified as potent PTP1B inhibitors. Among these analogues, compound 10 in particular showed improved PTP1B enzyme inhibitory activity, high selectivity for PTP1B over TC-PTP, and improved cellular effects.

Ultrasensitive Detection of Ricin Toxin in Multiple Sample Matrixes Using Single-Domain Antibodies.

PubMed

Gaylord, Shonda T; Dinh, Trinh L; Goldman, Ellen R; Anderson, George P; Ngan, Kevin C; Walt, David R

2015-07-07

Ricin is an extremely potent ribosomal inactivating protein listed as a Category B select agent. Although ricin intoxication is not transmittable from person to person, even a single ricin molecule can lead to cell necrosis because it inactivates 1500 ribosomes/min. Since there is currently no vaccine or therapeutic treatment for ricin intoxication, ultrasensitive analytical assays capable of detecting ricin in a variety of matrixes are urgently needed to limit exposure to individuals as well as communities. In this paper, we present the development and application of a single-molecule array (Simoa) for the detection of ricin toxin in human urine and serum. Single-domain antibodies (sdAbs), among the smallest engineered binding fragments, were chemically coupled to the surface of paramagnetic beads for the sensitive detection of ricin toxin. The Simoa was able to detect ricin at levels of 10 fg/mL, 100 fg/mL, and 1 pg/mL in buffer, urine and serum, respectively, in a fraction of the assay time need using immuno-polymerase chain reaction (IPCR). Using a fully automated state-of-the-art platform, the Simoa HD-1 analyzer, the assay time was reduced to 64 min.

Application of Asymmetric Flow Field-Flow Fractionation hyphenations for liposome-antimicrobial peptide interaction.

PubMed

Iavicoli, Patrizia; Urbán, Patricia; Bella, Angelo; Ryadnov, Maxim G; Rossi, François; Calzolai, Luigi

2015-11-27

Asymmetric Flow Field-Flow Fractionation (AF4) combined with multidetector analysis form a promising technique in the field of nanoparticle characterization. This system is able to measure the dimensions and physicochemical properties of nanoparticles with unprecedented accuracy and precision. Here, for the first time, this technique is optimized to characterize the interaction between an archetypal antimicrobial peptide and synthetic membranes. By using charged and neutral liposomes it is possible to mimic some of the charge characteristics of biological membranes. The use of AF4 system allows determining, in a single analysis, information regarding the selectivity of the peptides, the quantity of peptides bound to each liposome, the induced change in the size distribution and morphology of the liposomes. The results obtained provide relevant information for the study of structure-activity relationships in the context of membrane-induced antimicrobial action. This information will contribute to the rational design of potent antimicrobial agents in the future. Moreover, the application of this method to other liposome systems is straightforward and would be extremely useful for a comprehensive characterization with regard to size distribution and protein interaction in the nanomedicine field. Copyright © 2015. Published by Elsevier B.V.

Preclinical characterization of OSI-027, a potent and selective inhibitor of mTORC1 and mTORC2: distinct from rapamycin.

PubMed

Bhagwat, Shripad V; Gokhale, Prafulla C; Crew, Andrew P; Cooke, Andy; Yao, Yan; Mantis, Christine; Kahler, Jennifer; Workman, Jennifer; Bittner, Mark; Dudkin, Lorina; Epstein, David M; Gibson, Neil W; Wild, Robert; Arnold, Lee D; Houghton, Peter J; Pachter, Jonathan A

2011-08-01

The phosphoinositide 3-kinase (PI3K)/AKT/mTOR pathway is frequently activated in human cancers, and mTOR is a clinically validated target. mTOR forms two distinct multiprotein complexes, mTORC1 and mTORC2, which regulate cell growth, metabolism, proliferation, and survival. Rapamycin and its analogues partially inhibit mTOR through allosteric binding to mTORC1, but not mTORC2, and have shown clinical utility in certain cancers. Here, we report the preclinical characterization of OSI-027, a selective and potent dual inhibitor of mTORC1 and mTORC2 with biochemical IC(50) values of 22 nmol/L and 65 nmol/L, respectively. OSI-027 shows more than 100-fold selectivity for mTOR relative to PI3Kα, PI3Kβ, PI3Kγ, and DNA-PK. OSI-027 inhibits phosphorylation of the mTORC1 substrates 4E-BP1 and S6K1 as well as the mTORC2 substrate AKT in diverse cancer models in vitro and in vivo. OSI-027 and OXA-01 (close analogue of OSI-027) potently inhibit proliferation of several rapamycin-sensitive and -insensitive nonengineered and engineered cancer cell lines and also, induce cell death in tumor cell lines with activated PI3K-AKT signaling. OSI-027 shows concentration-dependent pharmacodynamic effects on phosphorylation of 4E-BP1 and AKT in tumor tissue with resulting tumor growth inhibition. OSI-027 shows robust antitumor activity in several different human xenograft models representing various histologies. Furthermore, in COLO 205 and GEO colon cancer xenograft models, OSI-027 shows superior efficacy compared with rapamycin. Our results further support the important role of mTOR as a driver of tumor growth and establish OSI-027 as a potent anticancer agent. OSI-027 is currently in phase I clinical trials in cancer patients. ©2011 AACR

The identification of 2-(1H-indazol-4-yl)-6-(4-methanesulfonyl-piperazin-1-ylmethyl)-4-morpholin-4-yl-thieno[3,2-d]pyrimidine (GDC-0941) as a potent, selective, orally bioavailable inhibitor of class I PI3 kinase for the treatment of cancer .

PubMed

Folkes, Adrian J; Ahmadi, Khatereh; Alderton, Wendy K; Alix, Sonia; Baker, Stewart J; Box, Gary; Chuckowree, Irina S; Clarke, Paul A; Depledge, Paul; Eccles, Suzanne A; Friedman, Lori S; Hayes, Angela; Hancox, Timothy C; Kugendradas, Arumugam; Lensun, Letitia; Moore, Pauline; Olivero, Alan G; Pang, Jodie; Patel, Sonal; Pergl-Wilson, Giles H; Raynaud, Florence I; Robson, Anthony; Saghir, Nahid; Salphati, Laurent; Sohal, Sukhjit; Ultsch, Mark H; Valenti, Melanie; Wallweber, Heidi J A; Wan, Nan Chi; Wiesmann, Christian; Workman, Paul; Zhyvoloup, Alexander; Zvelebil, Marketa J; Shuttleworth, Stephen J

2008-09-25

Phosphatidylinositol-3-kinase (PI3K) is an important target in cancer due to the deregulation of the PI3K/ Akt signaling pathway in a wide variety of tumors. A series of thieno[3,2-d]pyrimidine derivatives were prepared and evaluated as inhibitors of PI3 kinase p110alpha. The synthesis, biological activity, and further profiling of these compounds are described. This work resulted in the discovery of 17, GDC-0941, which is a potent, selective, orally bioavailable inhibitor of PI3K and is currently being evaluated in human clinical trials for the treatment of cancer.

Synthesis and Pharmacology of α/β(3)-Peptides Based on the Melanocortin Agonist Ac-His-dPhe-Arg-Trp-NH2 Sequence.

PubMed

Singh, Anamika; Tala, Srinivasa R; Flores, Viktor; Freeman, Katie; Haskell-Luevano, Carrie

2015-05-14

The melanocortin-3 and -4 receptors are expressed in the brain and play key roles in regulating feeding behavior, metabolism, and energy homeostasis. In the present study, incorporation of β(3)-amino acids into a melanocortin tetrapeptide template was investigated. Four linear α/β(3)-hybrid tetrapeptides were designed with the modifications at the Phe, Arg, and Trp residues in the agonist sequence Ac-His-dPhe-Arg-Trp-NH2. The most potent mouse melanocortin-4 receptor (mMC4R) agonist, Ac-His-dPhe-Arg-β(3)hTrp-NH2 (8) showed 35-fold selectivity versus the mMC3R. The study presented here has identified a new template with heterogeneous backbone for designing potent and selective melanocortin receptor ligands.

Synthesis and Pharmacology of α/β3-Peptides Based on the Melanocortin Agonist Ac-His-dPhe-Arg-Trp-NH2 Sequence

PubMed Central

2015-01-01

The melanocortin-3 and -4 receptors are expressed in the brain and play key roles in regulating feeding behavior, metabolism, and energy homeostasis. In the present study, incorporation of β3-amino acids into a melanocortin tetrapeptide template was investigated. Four linear α/β3-hybrid tetrapeptides were designed with the modifications at the Phe, Arg, and Trp residues in the agonist sequence Ac-His-dPhe-Arg-Trp-NH2. The most potent mouse melanocortin-4 receptor (mMC4R) agonist, Ac-His-dPhe-Arg-β3hTrp-NH2 (8) showed 35-fold selectivity versus the mMC3R. The study presented here has identified a new template with heterogeneous backbone for designing potent and selective melanocortin receptor ligands. PMID:26005535

Discovery of ((4R,5S)-5-amino-4-(2,4,5- trifluorophenyl)cyclohex-1-enyl)-(3- (trifluoromethyl)-5,6-dihydro- [1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone (ABT-341), a highly potent, selective, orally efficacious, and safe dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes.

PubMed

Pei, Zhonghua; Li, Xiaofeng; von Geldern, Thomas W; Madar, David J; Longenecker, Kenton; Yong, Hong; Lubben, Thomas H; Stewart, Kent D; Zinker, Bradley A; Backes, Bradley J; Judd, Andrew S; Mulhern, Mathew; Ballaron, Stephen J; Stashko, Michael A; Mika, Amanda K; Beno, David W A; Reinhart, Glenn A; Fryer, Ryan M; Preusser, Lee C; Kempf-Grote, Anita J; Sham, Hing L; Trevillyan, James M

2006-11-02

Dipeptidyl peptidase IV (DPP4) deactivates glucose-regulating hormones such as GLP-1 and GIP, thus, DPP4 inhibition has become a useful therapy for type 2 diabetes. Optimization of the high-throughput screening lead 6 led to the discovery of 25 (ABT-341), a highly potent, selective, and orally bioavailable DPP4 inhibitor. When dosed orally, 25 dose-dependently reduced glucose excursion in ZDF rats. Amide 25 is safe in a battery of in vitro and in vivo tests and may represent a new therapeutic agent for the treatment of type 2 diabetes.

Design, biological evaluation and 3D QSAR studies of novel dioxin-containing pyrazoline derivatives with thiourea skeleton as selective HER-2 inhibitors

NASA Astrophysics Data System (ADS)

Yang, Bing; Yang, Yu-Shun; Yang, Na; Li, Guigen; Zhu, Hai-Liang

2016-06-01

A series of novel dioxin-containing pyrazoline derivatives with thiourea skeleton have been designed, synthesized and evaluated for their EGFR/HER-2 inhibitory and anti-proliferation activities. A majority of them displayed selective HER-2 inhibitory activity against EGFR inhibitory activity. Compound C20 displayed the most potent activity against HER-2 and MDA-MB-453 human breast cancer cell line (IC50 = 0.03 μM and GI50 = 0.15 μM), being slightly more potent than the positive control Erlotinib (IC50 = 0.16 μM and GI50 = 1.56 μM) and comparable with Lapatinib (IC50 = 0.01 μM and GI50 = 0.03 μM). It is a more exciting result that C20 was over 900 times more potent against HER-2 than against EGFR while this value was 0.19 for Erlotinib and 1.00 for Lapatinib, indicating high selectivity. The results of docking simulation indicate that the dioxin moiety occupied the exit of the active pocket and pushed the carbothioamide deep into the active site. QSAR models have been built with activity data and binding conformations to begin our work in this paper as well as to provide a reliable tool for reasonable design of EGFR/HER-2 inhibitors in future.

Discovery of potent and selective acetylcholinesterase (AChE) inhibitors: acacetin 7-O-methyl ether Mannich base derivatives synthesised from easy access natural product naringin.

PubMed

Liu, Hao-Ran; Men, Xue; Gao, Xiao-Hui; Liu, Lin-Bo; Fan, Hao-Qun; Xia, Xin-Hua; Wang, Qiu-An

2018-03-01

Naringin, as a component universal existing in the peel of some fruits or medicinal plants, was usually selected as the material to synthesise bioactive derivates since it was easy to gain with low cost. In present investigation, eight new acacetin-7-O-methyl ether Mannich base derivatives (1-8) were synthesised from naringin. The bioactivity evaluation revealed that most of them exhibited moderate or potent acetylcholinesterase (AChE) inhibitory activity. Among them, compound 7 (IC 50 for AChE = 0.82 ± 0.08 μmol•L -1 , IC 50 for BuChE = 46.30 ± 3.26 μmol•L -1 ) showed a potent activity and high selectivity compared with the positive control Rivastigmine (IC 50 for AChE = 10.54 ± 0.86 μmol•L -1 , IC 50 for BuChE = 0.26 ± 0.08 μmol•L -1 ). The kinetic study suggested that compound 7 bind to AChE with mix-type inhibitory profile. Molecular docking study revealed that compound 7 could combine both catalytic active site (CAS) and peripheral active site (PAS) of AChE with four points (Trp84, Trp279, Tyr70 and Phe330), while it could bind with BuChE via only His 20.

Low Antigen Dose in Adjuvant-Based Vaccination Selectively Induces CD4 T Cells with Enhanced Functional Avidity and Protective Efficacy

PubMed Central

Wang, Yichuan; Solaymani-Mohammadi, Shahram; Frey, Blake; Kulkarni, Shweta; Andersen, Peter; Agger, Else Marie; Sui, Yongjun

2017-01-01

T cells with high functional avidity can sense and respond to low levels of cognate Ag, a characteristic that is associated with more potent responses against tumors and many infections, including HIV. Although an important determinant of T cell efficacy, it has proven difficult to selectively induce T cells of high functional avidity through vaccination. Attempts to induce high-avidity T cells by low-dose in vivo vaccination failed because this strategy simply gave no response. Instead, selective induction of high-avidity T cells has required in vitro culturing of specific T cells with low Ag concentrations. In this study, we combined low vaccine Ag doses with a novel potent cationic liposomal adjuvant, cationic adjuvant formulation 09, consisting of dimethyldioctadecylammonium liposomes incorporating two immunomodulators (monomycolyl glycerol analog and polyinosinic-polycytidylic acid) that efficiently induces CD4 Th cells, as well as cross-primes CD8 CTL responses. We show that vaccination with low Ag dose selectively primes CD4 T cells of higher functional avidity, whereas CD8 T cell functional avidity was unrelated to vaccine dose in mice. Importantly, CD4 T cells of higher functional avidity induced by low-dose vaccinations showed higher cytokine release per cell and lower inhibitory receptor expression (PD-1, CTLA-4, and the apoptosis-inducing Fas death receptor) compared with their lower-avidity CD4 counterparts. Notably, increased functional CD4 T cell avidity improved antiviral efficacy of CD8 T cells. These data suggest that potent adjuvants, such as cationic adjuvant formulation 09, render low-dose vaccination a feasible and promising approach for generating high-avidity T cells through vaccination. PMID:28348274

Biochemical and pharmacological properties of SR 49059, a new, potent, nonpeptide antagonist of rat and human vasopressin V1a receptors.

PubMed

Serradeil-Le Gal, C; Wagnon, J; Garcia, C; Lacour, C; Guiraudou, P; Christophe, B; Villanova, G; Nisato, D; Maffrand, J P; Le Fur, G

1993-07-01

SR 49059, a new potent and selective orally active, nonpeptide vasopressin (AVP) antagonist has been characterized in several in vitro and in vivo models. SR 49059 showed high affinity for V1a receptors from rat liver (Ki = 1.6 +/- 0.2) and human platelets, adrenals, and myometrium (Ki ranging from 1.1 to 6.3 nM). The previously described nonpeptide V1 antagonist, OPC-21268, was almost inactive in human tissues at concentrations up to 100 microM. SR 49059 exhibited much lower affinity (two orders of magnitude or more) for AVP V2 (bovine and human), V1b (human), and oxytocin (rat and human) receptors and had no measurable affinity for a great number of other receptors. In vitro, AVP-induced contraction of rat caudal artery was competitively antagonized by SR 49059 (pA2 = 9.42). Furthermore, SR 49059 inhibited AVP-induced human platelet aggregation with an IC50 value of 3.7 +/- 0.4 nM, while OPC-21268 was inactive up to 20 microM. In vivo, SR 49059 inhibited the pressor response to exogenous AVP in pithed rats (intravenous) and in conscious normotensive rats (intravenous and per os) with a long duration of action (> 8 h at 10 mg/kg p.o). In all the biological assays used, SR 49059 was devoid of any intrinsic agonistic activity. Thus, SR 49059 is the most potent and selective nonpeptide AVP V1a antagonist described so far, with marked affinity, selectivity, and efficacy toward both animal and human receptors. With this original profile, SR 49059 constitutes a powerful tool for exploring the therapeutical usefulness of a selective V1a antagonist.

Exploring the utility of organo-polyoxometalate hybrids to inhibit SOX transcription factors

PubMed Central

2014-01-01

Background SOX transcription factors constitute an attractive target class for intervention with small molecules as they play a prominent role in the field of regenerative biomedicine and cancer biology. However, rationally engineering specific inhibitors that interfere with transcription factor DNA interfaces continues to be a monumental challenge in the field of transcription factor chemical biology. Polyoxometalates (POMs) are inorganic compounds that were previously shown to target the high-mobility group (HMG) of SOX proteins at nanomolar concentrations. In continuation of this work, we carried out an assessment of the selectivity of a panel of newly synthesized organo-polyoxometalate hybrids in targeting different transcription factor families to enable the usage of polyoxometalates as specific SOX transcription factor drugs. Results The residual DNA-binding activities of 15 different transcription factors were measured after treatment with a panel of diverse polyoxometalates. Polyoxometalates belonging to the Dawson structural class were found to be more potent inhibitors than the Keggin class. Further, organically modified Dawson polyoxometalates were found to be the most potent in inhibiting transcription factor DNA binding activity. The size of the polyoxometalates and its derivitization were found to be the key determinants of their potency. Conclusion Polyoxometalates are highly potent, nanomolar range inhibitors of the DNA binding activity of the Sox-HMG family. However, binding assays involving a limited subset of structurally diverse polyoxometalates revealed a low selectivity profile against different transcription factor families. Further progress in achieving selectivity and deciphering structure-activity relationship of POMs require the identification of POM binding sites on transcription factors using elaborate approaches like X-ray crystallography and multidimensional NMR. In summary, our report reaffirms that transcription factors are challenging molecular architectures and that future polyoxometalate chemistry must consider further modification strategies, to address the substantial challenges involved in achieving target selectivity. PMID:25678957

Interaction of antithrombin with sulfated, low molecular weight lignins: opportunities for potent, selective modulation of antithrombin function.

PubMed

Henry, Brian L; Connell, Justin; Liang, Aiye; Krishnasamy, Chandravel; Desai, Umesh R

2009-07-31

Antithrombin, a major regulator of coagulation and angiogenesis, is known to interact with several natural sulfated polysaccharides. Previously, we prepared sulfated low molecular weight variants of natural lignins, called sulfated dehydrogenation polymers (DHPs) (Henry, B. L., Monien, B. H., Bock, P. E., and Desai, U. R. (2007) J. Biol. Chem. 282, 31891-31899), which have now been found to exhibit interesting antithrombin binding properties. Sulfated DHPs represent a library of diverse noncarbohydrate aromatic scaffolds that possess structures completely different from heparin and heparan sulfate. Fluorescence binding studies indicate that sulfated DHPs bind to antithrombin with micromolar affinity under physiological conditions. Salt dependence of binding affinity indicates that the antithrombin-sulfated DHP interaction involves a massive 80-87% non-ionic component to the free energy of binding. Competitive binding studies with heparin pentasaccharide, epicatechin sulfate, and full-length heparin indicate that sulfated DHPs bind to both the pentasaccharide-binding site and extended heparin-binding site of antithrombin. Affinity capillary electrophoresis resolves a limited number of peaks of antithrombin co-complexes suggesting preferential binding of selected DHP structures to the serpin. Computational genetic algorithm-based virtual screening study shows that only one sulfated DHP structure, out of the 11 present in a library of plausible sequences, bound in the heparin-binding site with a high calculated score supporting selectivity of recognition. Enzyme inhibition studies indicate that only one of the three sulfated DHPs studied is a potent inhibitor of free factor VIIa in the presence of antithrombin. Overall, the chemo-enzymatic origin and antithrombin binding properties of sulfated DHPs present novel opportunities for potent and selective modulation of the serpin function, especially for inhibiting the initiation phase of hemostasis.

Selectivity of ROCK inhibitors in the spontaneously tonic smooth muscle.

PubMed

Rattan, Satish; Patel, Chirag A

2008-03-01

The selectivity of different Rho kinase (ROCK) inhibitors in the spontaneously tonic smooth muscle has not been investigated. We examined this issue using Y-27632 [(R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarbox anecarboxamide, 2HCl], H-1152 [(S)-(+)-(2-methyl-5-isoquinolinyl) sulfonylhomopiperazine, 2HCl], HA-1077 [(5 isoquinolinesulfonyl) homopiperazine, 2HCl], and ROCK inhibitor II [N-(4-pyridyl)-N'-(2,4,6-trichlorophenyl)urea]. We compared these inhibitors in the spontaneously tonic smooth muscle of the internal anal sphincter (IAS). ROCK, protein kinase C (PKC), and myosin light chain kinase (MLCK) activities were determined in the IAS, before and after different ROCK inhibitors. Y-27632 and H-1152 were approximately 30-fold more potent in the IAS (IC(50): 4.4 x 10(-7) and 7.9 x 10(-8) M, respectively) vs. the phasic rectal smooth muscle (RSM) (IC(50): 1.3 x 10(-5) and 2.5 x 10(-6) M, respectively). HA-1077 and ROCK inhibitor II were equipotent in the IAS vs. RSM. In the IAS, H-1152 was the most potent whereas ROCK inhibitor II is the least. Y-27632 and H-1152 caused concentration-dependent decrease in the IAS tone that correlates directly with the decreases in ROCK activity, without significant effect in the PKC and MLCK activities. This specifically selective correlation between ROCK activity and decrease in the IAS tone was absent in the case of HA-1077 and ROCK inhibitor II, which also inhibited PKC and MLCK. We conclude that the IAS tone is critically dependent on ROCK activity, and H-1152 and Y-27632 are the most selective and potent ROCK inhibitors in the IAS.

Anticancer Drugs from Marine Flora: An Overview

PubMed Central

Sithranga Boopathy, N.; Kathiresan, K.

2010-01-01

Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease. PMID:21461373

Tetrodotoxin, an Extremely Potent Marine Neurotoxin: Distribution, Toxicity, Origin and Therapeutical Uses

PubMed Central

Lago, Jorge; Rodríguez, Laura P.; Blanco, Lucía; Vieites, Juan Manuel; Cabado, Ana G.

2015-01-01

Tetrodotoxin (TTX) is a potent neurotoxin responsible for many human intoxications and fatalities each year. The origin of TTX is unknown, but in the pufferfish, it seems to be produced by endosymbiotic bacteria that often seem to be passed down the food chain. The ingestion of contaminated pufferfish, considered the most delicious fish in Japan, is the usual route of toxicity. This neurotoxin, reported as a threat to human health in Asian countries, has spread to the Pacific and Mediterranean, due to the increase of temperature waters worldwide. TTX, for which there is no known antidote, inhibits sodium channel producing heart failure in many cases and consequently death. In Japan, a regulatory limit of 2 mg eq TTX/kg was established, although the restaurant preparation of “fugu” is strictly controlled by law and only chefs qualified are allowed to prepare the fish. Due to its paralysis effect, this neurotoxin could be used in the medical field as an analgesic to treat some cancer pains. PMID:26492253

Interbilayer-crosslinked multilamellar vesicles as synthetic vaccines for potent humoral and cellular immune responses

NASA Astrophysics Data System (ADS)

Moon, James J.; Suh, Heikyung; Bershteyn, Anna; Stephan, Matthias T.; Liu, Haipeng; Huang, Bonnie; Sohail, Mashaal; Luo, Samantha; Ho Um, Soong; Khant, Htet; Goodwin, Jessica T.; Ramos, Jenelyn; Chiu, Wah; Irvine, Darrell J.

2011-03-01

Vaccines based on recombinant proteins avoid the toxicity and antivector immunity associated with live vaccine (for example, viral) vectors, but their immunogenicity is poor, particularly for CD8+ T-cell responses. Synthetic particles carrying antigens and adjuvant molecules have been developed to enhance subunit vaccines, but in general these materials have failed to elicit CD8+ T-cell responses comparable to those for live vectors in preclinical animal models. Here, we describe interbilayer-crosslinked multilamellar vesicles formed by crosslinking headgroups of adjacent lipid bilayers within multilamellar vesicles. Interbilayer-crosslinked vesicles stably entrapped protein antigens in the vesicle core and lipid-based immunostimulatory molecules in the vesicle walls under extracellular conditions, but exhibited rapid release in the presence of endolysosomal lipases. We found that these antigen/adjuvant-carrying vesicles form an extremely potent whole-protein vaccine, eliciting endogenous T-cell and antibody responses comparable to those for the strongest vaccine vectors. These materials should enable a range of subunit vaccines and provide new possibilities for therapeutic protein delivery.

Anticancer drugs from marine flora: an overview.

PubMed

Sithranga Boopathy, N; Kathiresan, K

2010-01-01

Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease.

Development of a potent 2-oxoamide inhibitor of secreted phospholipase A2 guided by molecular docking calculations and molecular dynamics simulations

PubMed Central

Vasilakaki, Sofia; Barbayianni, Efrosini; Leonis, Georgios; Papadopoulos, Manthos G.; Mavromoustakos, Thomas; Gelb, Michael H.; Kokotos, George

2016-01-01

Inhibition of group IIA secreted phospholipase A2 (GIIA sPLA2) has been an important objective for medicinal chemists. We have previously shown that inhibitors incorporating the 2-oxoamide functionality may inhibit human and mouse GIIA sPLA2s. Herein, the development of new potent inhibitors by molecular docking calculations using the structure of the known inhibitor 7 as scaffold, are described. Synthesis and biological evaluation of the new compounds revealed that the long chain 2-oxoamide based on (S)-valine GK241 led to improved activity (IC50 = 143 nM and 68 nM against human and mouse GIIA sPLA2, respectively). In addition, molecular dynamics simulations were employed to shed light on GK241 potent and selective inhibitory activity. PMID:26970660

Identification of bicyclic hexafluoroisopropyl alcohol sulfonamides as retinoic acid receptor-related orphan receptor gamma (RORγ/RORc) inverse agonists. Employing structure-based drug design to improve pregnane X receptor (PXR) selectivity.

PubMed

Gong, Hua; Weinstein, David S; Lu, Zhonghui; Duan, James J-W; Stachura, Sylwia; Haque, Lauren; Karmakar, Ananta; Hemagiri, Hemalatha; Raut, Dhanya Kumar; Gupta, Arun Kumar; Khan, Javed; Camac, Dan; Sack, John S; Pudzianowski, Andrew; Wu, Dauh-Rurng; Yarde, Melissa; Shen, Ding-Ren; Borowski, Virna; Xie, Jenny H; Sun, Huadong; D'Arienzo, Celia; Dabros, Marta; Galella, Michael A; Wang, Faye; Weigelt, Carolyn A; Zhao, Qihong; Foster, William; Somerville, John E; Salter-Cid, Luisa M; Barrish, Joel C; Carter, Percy H; Dhar, T G Murali

2018-01-15

We disclose the optimization of a high throughput screening hit to yield benzothiazine and tetrahydroquinoline sulfonamides as potent RORγt inverse agonists. However, a majority of these compounds showed potent activity against pregnane X receptor (PXR) and modest activity against liver X receptor α (LXRα). Structure-based drug design (SBDD) led to the identification of benzothiazine and tetrahydroquinoline sulfonamide analogs which completely dialed out LXRα activity and were less potent at PXR. Pharmacodynamic (PD) data for compound 35 in an IL-23 induced IL-17 mouse model is discussed along with the implications of a high Y max in the PXR assay for long term preclinical pharmacokinetic (PK) studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of Amide and Ester Derivatives of Cinnamic Acid and Its Analogs: Evaluation of Their Free Radical Scavenging and Monoamine Oxidase and Cholinesterase Inhibitory Activities.

PubMed

Takao, Koichi; Toda, Kazuhiro; Saito, Takayuki; Sugita, Yoshiaki

2017-01-01

A series of cinnamic acid derivatives, amides (1-12) and esters (13-22), were synthesized, and structure-activity relationships for antioxidant activity, and monoamine oxidases (MAO) A and B, acetylcholinesterase, and butyrylcholinesterase (BChE) inhibitory activities were analyzed. Among the synthesized compounds, compounds 1-10, 12-18, and rosmarinic acid (23), which contained catechol, o-methoxyphenol or 5-hydroxyindole moieties, showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Compounds 9-11, 15, 17-22 showed potent and selective MAO-B inhibitory activity. Compound 20 was the most potent inhibitor of MAO-B. Compounds 18 and 21 showed moderate BChE inhibitory activity. In addition, compound 18 showed potent antioxidant activity and MAO-B inhibitory activity. In a comparison of the cinnamic acid amides and esters, the amides exhibited more potent DPPH free radical scavenging activity, while the esters showed stronger inhibitory activities against MAO-B and BChE. These results suggested that cinnamic acid derivatives such as compound 18, p-coumaric acid 3,4-dihydroxyphenethyl ester, and compound 20, p-coumaric acid phenethyl ester, may serve as lead compounds for the development of novel MAO-B inhibitors and candidate lead compounds for the prevention or treatment of Alzheimer's disease.

A New Integrated Threshold Selection Methodology for Spatial Forecast Verification of Extreme Events

NASA Astrophysics Data System (ADS)

Kholodovsky, V.

2017-12-01

Extreme weather and climate events such as heavy precipitation, heat waves and strong winds can cause extensive damage to the society in terms of human lives and financial losses. As climate changes, it is important to understand how extreme weather events may change as a result. Climate and statistical models are often independently used to model those phenomena. To better assess performance of the climate models, a variety of spatial forecast verification methods have been developed. However, spatial verification metrics that are widely used in comparing mean states, in most cases, do not have an adequate theoretical justification to benchmark extreme weather events. We proposed a new integrated threshold selection methodology for spatial forecast verification of extreme events that couples existing pattern recognition indices with high threshold choices. This integrated approach has three main steps: 1) dimension reduction; 2) geometric domain mapping; and 3) thresholds clustering. We apply this approach to an observed precipitation dataset over CONUS. The results are evaluated by displaying threshold distribution seasonally, monthly and annually. The method offers user the flexibility of selecting a high threshold that is linked to desired geometrical properties. The proposed high threshold methodology could either complement existing spatial verification methods, where threshold selection is arbitrary, or be directly applicable in extreme value theory.

Biobased extreme pressure additives: Structure-property considerations

USDA-ARS?s Scientific Manuscript database

Extreme pressure additives are widely used in lubricant formulations for engine oils, hydraulic fluids, gear oils, metalworking fluids, and many others. Extreme pressure additives contain selected elements such as sulfur, phosphorus, and halogens in their structures. These elements, under extreme tr...

New Dendrimer-Based Nanoparticles Enhance Curcumin Solubility.

PubMed

Falconieri, Maria Cristina; Adamo, Mauro; Monasterolo, Claudio; Bergonzi, Maria Camilla; Coronnello, Marcella; Bilia, Anna Rita

2017-03-01

Curcumin, the main curcuminoid of the popular Indian spice turmeric, is a potent chemopreventive agent and useful in many different diseases. A major limitation of applicability of curcumin as a health promoting and medicinal agent is its extremely low bioavailability due to efficient first pass metabolism, poor gastrointestinal absorption, rapid elimination, and poor aqueous solubility. In the present study, nanotechnology was selected as a choice approach to enhance the bioavailability of the curcuminis. A new polyamidoamine dendrimer (G0.5) was synthesized, characterized, and tested for cytotoxicity in human breast cancer cells (MCF-7). No cytotoxicity of G0.5 was found in the range between 10 -3 and 3 × 10 -8  M. Consequently, G0.5 was used to prepare spherical nanoparticles of ca. 150 nm, which were loaded with curcumin [molar ratio G0.5/curcumin 1 : 1 (formulation 1) and 1 : 0.5 (formulation 2)]. Remarkably, the occurrence of a single population of nanoparticles having an excellent polydispersity index (< 0.20) was found in both formulations. Formulation 1 was selected to test in vitro drug release because it was superior in terms of encapsulation efficiency (62 %) and loading capacity (32 %). The solubility of curcumin was increased ca. 415 and 150 times with respect to the unformulated drug, respectively, for formulation 1 and formulation 2. The release of curcumin from the nanoparticles showed an interesting prolonged and sustained release profile. Georg Thieme Verlag KG Stuttgart · New York.

Structure-based design, synthesis, and biological evaluation of imidazo[1,2-b]pyridazine-based p38 MAP kinase inhibitors.

PubMed

Kaieda, Akira; Takahashi, Masashi; Takai, Takafumi; Goto, Masayuki; Miyazaki, Takahiro; Hori, Yuri; Unno, Satoko; Kawamoto, Tomohiro; Tanaka, Toshimasa; Itono, Sachiko; Takagi, Terufumi; Hamada, Teruki; Shirasaki, Mikio; Okada, Kengo; Snell, Gyorgy; Bragstad, Ken; Sang, Bi-Ching; Uchikawa, Osamu; Miwatashi, Seiji

2018-02-01

We identified novel potent inhibitors of p38 MAP kinase using structure-based design strategy. X-ray crystallography showed that when p38 MAP kinase is complexed with TAK-715 (1) in a co-crystal structure, Phe169 adopts two conformations, where one interacts with 1 and the other shows no interaction with 1. Our structure-based design strategy shows that these two conformations converge into one via enhanced protein-ligand hydrophobic interactions. According to the strategy, we focused on scaffold transformation to identify imidazo[1,2-b]pyridazine derivatives as potent inhibitors of p38 MAP kinase. Among the herein described and evaluated compounds, N-oxide 16 exhibited potent inhibition of p38 MAP kinase and LPS-induced TNF-α production in human monocytic THP-1 cells, and significant in vivo efficacy in rat collagen-induced arthritis models. In this article, we report the discovery of potent, selective and orally bioavailable imidazo[1,2-b]pyridazine-based p38 MAP kinase inhibitors with pyridine N-oxide group. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

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.

Novel inhibitors of IMPDH: a highly potent and selective quinolone-based series.

PubMed

Watterson, Scott H; Carlsen, Marianne; Dhar, T G Murali; Shen, Zhongqi; Pitts, William J; Guo, Junqing; Gu, Henry H; Norris, Derek; Chorba, John; Chen, Ping; Cheney, Daniel; Witmer, Mark; Fleener, Catherine A; Rouleau, Katherine; Townsend, Robert; Hollenbaugh, Diane L; Iwanowicz, Edwin J

2003-02-10

A series of novel quinolone-based small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH) was explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are described.

Generalized extreme gust wind speeds distributions

USGS Publications Warehouse

Cheng, E.; Yeung, C.

2002-01-01

Since summer 1996, the US wind engineers are using the extreme gust (or 3-s gust) as the basic wind speed to quantify the destruction of extreme winds. In order to better understand these destructive wind forces, it is important to know the appropriate representations of these extreme gust wind speeds. Therefore, the purpose of this study is to determine the most suitable extreme value distributions for the annual extreme gust wind speeds recorded in large selected areas. To achieve this objective, we are using the generalized Pareto distribution as the diagnostic tool for determining the types of extreme gust wind speed distributions. The three-parameter generalized extreme value distribution function is, thus, reduced to either Type I Gumbel, Type II Frechet or Type III reverse Weibull distribution function for the annual extreme gust wind speeds recorded at a specific site.With the considerations of the quality and homogeneity of gust wind data collected at more than 750 weather stations throughout the United States, annual extreme gust wind speeds at selected 143 stations in the contiguous United States were used in the study. ?? 2002 Elsevier Science Ltd. All rights reserved.

Imported fire ants: the ants from hell!

PubMed

Freeman, T M

1994-01-01

Imported fire ants may certainly be considered the ANTS FROM HELL! This review focuses on both the interesting entomology of fire ants and the important medical characteristics of fire ant stings. They sting and they kill; they destroy; they mate in mid-air; and we may not be able to stop them. However, although they inject extremely potent venom, individuals can prevent secondary infections by leaving the so-called pustules alone and not opening them. Individuals who suffer systemic reactions may receive adequate treatment with the whole body extract immunotherapy.

2-Aminomethylthieno[3,2-d]pyrimidin-4(3H)-ones bearing 3-methylpyrazole hinge binding moiety: Highly potent, selective, and time-dependent inhibitors of Cdc7 kinase.

PubMed

Kurasawa, Osamu; Homma, Misaki; Oguro, Yuya; Miyazaki, Tohru; Mori, Kouji; Uchiyama, Noriko; Iwai, Kenichi; Ohashi, Akihiro; Hara, Hideto; Yoshida, Sei; Cho, Nobuo

2017-07-15

In order to increase the success rate for developing new Cdc7 inhibitors for cancer therapy, we explored a new chemotype which can comply with the previously-constructed pharmacophore model. Substitution of a pyridine ring of a serendipitously-identified Cdc7 inhibitor 2b with a 3-methylpyrazole resulted in a 4-fold increase in potency and acceptable kinase selectivity, leading to the identification of thieno[3,2-d]pyrimidin-4(3H)-one as an alternative scaffold. Structure-activity relationship (SAR) study revealed that incorporation of a substituted aminomethyl group into the 2-position improved kinase selectivity. Indeed, a pyrrolidinylmethyl derivative 10c was a potent Cdc7 inhibitor (IC 50 =0.70nM) with high selectivity (Cdk2/Cdc7≥14,000, ROCK1/Cdc7=200). It should be noted that 10c exhibited significant time-dependent Cdc7 inhibition with slow dissociation kinetics, cellular pharmacodynamic (PD) effects, and COLO205 growth inhibition. Additionally, molecular basis of high kinase selectivity of 10c is discussed by using the protein structures of Cdc7 and Cdk2. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solid-phase synthesis and insights into structure-activity relationships of safinamide analogues as potent and selective inhibitors of type B monoamine oxidase.

PubMed

Leonetti, Francesco; Capaldi, Carmelida; Pisani, Leonardo; Nicolotti, Orazio; Muncipinto, Giovanni; Stefanachi, Angela; Cellamare, Saverio; Caccia, Carla; Carotti, Angelo

2007-10-04

Safinamide, (S)-N2-{4-[(3-fluorobenzyl)oxy]benzyl}alaninamide methanesulfonate, which is in phase III clinical trials as an anti-Parkinson drug, and a library of alkanamidic analogues were prepared through an expeditious solid-phase synthesis and evaluated for their monoamine oxidase B (MAO-B) and monoamine oxidase A (MAO-A) inhibitory activity and selectivity. (S)-3-Chlorobenzyloxyalaninamide (8) and (S)-3-chlorobenzyloxyserinamide (13) derivatives proved to be more potent MAO-B inhibitors than safinamide (IC50 = 33 and 43 nM, respectively, vs 98 nM) but with a lower MAO-B selectivity (SI = 3455 and 1967, respectively, vs 5918). The highest MAO-B inhibitory potency (IC50 = 17 nM) and a good selectivity (SI = 2941) were displayed by (R)-21, a tetrahydroisoquinoline analogue of safinamide. Structure-affinity relationships and docking simulations pointed out strong negative steric effects of alpha-aminoamide side chains and para substituents of the benzyloxy groups and favorable hydrophobic interactions of meta substituents. The significantly diverse MAO-B affinities of a number of R and S alpha-aminoamide enantiomers, including the two rigid analogues (21) of safinamide, indicated likely enantioselective interactions at the enzymatic binding sites.

Catecholic amides as potential selective phosphodiesterase 4D inhibitors: Design, synthesis, pharmacological evaluation and structure-activity relationships.

PubMed

Zhou, Zhong-Zhen; Ge, Bing-Chen; Chen, Yu-Fang; Shi, Xiu-Dong; Yang, Xue-Mei; Xu, Jiang-Ping

2015-11-15

In this study, a series of catechol-based amides (8a-n) with different amide linkers linking the catecholic moiety to the terminal phenyl ring was designed and synthesized as potent phosphodiesterase (PDE) 4D inhibitors. The inhibitory activities of these compounds were evaluated against the core catalytic domains of human PDE4 (PDE4CAT), full-length PDE4B1 and PDE4D7 enzymes, and other PDE family members. The results indicated the majority of compounds 8a-n displayed moderate to good inhibitory activities against PDE4CAT. Among these compounds, compound 8 j with a short amide linker (-CONHCH2-) displayed comparable PDE4CAT inhibitory activity (IC50=410 nM) with rolipram. More interestingly, compound 8 g, a potent and selective PDE4D inhibitor (IC50=94 nM), exhibited a 10-fold selectivity over the PDE4B subtypes and an over 1000-fold selectivity against other PDE family members. Docking simulations suggested that 8 g forms three extra H-bonds with the N-H of residue Asn487 and two water molecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preclinical and clinical properties of trimegestone: a potent and selective progestin.

PubMed

Sitruk-Ware, Regine; Bossemeyer, Ronald; Bouchard, Phillipe

2007-06-01

Trimegestone (TMG) is a novel, 19-norpregnane progestin with potent and selective properties. In preclinical studies, TMG has been shown to provide high endometrial selectivity. Further, TMG has high affinity and selectivity for the progesterone receptor and lacks the agonist effects of other steroid hormones. In clinical studies, TMG has been shown to have high endometrial safety and an improved bleeding profile along with improved tolerability compared with other progestins. In addition, TMG also does not impede the beneficial effects of estrogen, especially on bone, and does not compromise quality of life. The preclinical findings of lack of mineralocorticoid activity of TMG were supported in clinical findings, with neutral effect on body weight. Similarly, the smaller effect of TMG on the GABA-ergic (gamma-aminobutyric acid) system in preclinical studies is consistent with the improvement of central nervous system-related effects on depressed mood and sleep quality in clinical studies. Low-dose estradiol/TMG regimens provide rapid relief from menopausal symptoms, reducing the number and severity of hot flushes as effectively as 2 mg 17beta-estradiol/1 mg norethisterone acetate. Therefore, it may be concluded that TMG provides a clinically proven option in hormone therapy for both clinicians and patients.

Inhibitors Selective for Mycobacterial Versus Human Proteasomes

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

Lin, G.; Li, D; Sorio de Carvalho, L

Many anti-infectives inhibit the synthesis of bacterial proteins, but none selectively inhibits their degradation. Most anti-infectives kill replicating pathogens, but few preferentially kill pathogens that have been forced into a non-replicating state by conditions in the host. To explore these alternative approaches we sought selective inhibitors of the proteasome of Mycobacterium tuberculosis. Given that the proteasome structure is extensively conserved, it is not surprising that inhibitors of all chemical classes tested have blocked both eukaryotic and prokaryotic proteasomes, and no inhibitor has proved substantially more potent on proteasomes of pathogens than of their hosts. Here we show that certain oxathiazol-2-onemore » compounds kill non-replicating M.?tuberculosis and act as selective suicide-substrate inhibitors of the M.?tuberculosis proteasome by cyclocarbonylating its active site threonine. Major conformational changes protect the inhibitor-enzyme intermediate from hydrolysis, allowing formation of an oxazolidin-2-one and preventing regeneration of active protease. Residues outside the active site whose hydrogen bonds stabilize the critical loop before and after it moves are extensively non-conserved. This may account for the ability of oxathiazol-2-one compounds to inhibit the mycobacterial proteasome potently and irreversibly while largely sparing the human homologue.« less

Pharmacological stress myocardial perfusion imaging with the potent and selective A(2A) adenosine receptor agonists ATL193 and ATL146e administered by either intravenous infusion or bolus injection.

PubMed

Glover, D K; Ruiz, M; Takehana, K; Petruzella, F D; Riou, L M; Rieger, J M; Macdonald, T L; Watson, D D; Linden, J; Beller, G A

2001-09-04

Adenosine (Ado) and dipyridamole are alternatives to exercise stress for myocardial perfusion imaging. Though generally safe, side effects frequently occur that cause patient discomfort and sometimes lead to premature termination of the study or require aminophylline administration. Recently, a new class of A(2A) Ado receptor agonists was synthesized. ATL193 and ATL146e are 2-propynylcyclohexyl-5'-N-ethylcarboxamido derivatives of Ado. The study goals were to evaluate the potency and selectivity of these new compounds on recombinant canine Ado receptors and to evaluate their hemodynamic properties in dogs to assess their usefulness as vasodilators for myocardial perfusion imaging. In assays of recombinant canine Ado receptors, ATL-193 and ATL-146e were highly selective for the A(2A) over the A(1) and A(3) receptors and were more potent than MRE-0470 and CGS-21680. In 16 anesthetized dogs, the agonists were administered by infusion (ATL-193; n=7 normal) or bolus injection (ATL-146e; n=9 critical left anterior descending coronary artery stenosis), and hemodynamic responses were compared with those of Ado. Both agonists produced dose-dependent coronary flow (CF) elevation without provoking the hypotension observed with Ado. After an ATL-146e bolus, the CF increase was sustained for several minutes, providing ample time for injection and myocardial uptake of (99m)Tc-sestamibi, and CF returned to baseline within 20 minutes. The CF increase was completely blocked by the selective A(2A) antagonist ZM241385 (3 microgram. kg(-1). min(-1)). ATL-193 and ATL-146e are highly potent and selective Ado A(2A) receptor agonists with excellent potential for use as vasodilators for myocardial perfusion imaging. An important advantage of ATL-146e is the ability to administer it by bolus injection.

Significant reduction of acute cardiac allograft rejection by selective janus kinase-1/3 inhibition using R507 and R545.

PubMed

Deuse, Tobias; Hua, Xiaoqin; Taylor, Vanessa; Stubbendorff, Mandy; Baluom, Muhammad; Chen, Yan; Park, Gary; Velden, Joachim; Streichert, Thomas; Reichenspurner, Hermann; Robbins, Robert C; Schrepfer, Sonja

2012-10-15

Selective inhibition of lymphocyte activation through abrogation of signal 3-cytokine transduction emerges as a new strategy for immunosuppression. This is the first report on the novel Janus kinase (JAK)1/3 inhibitors R507 and R545 for prevention of acute allograft rejection. Pharmacokinetic and in vitro enzyme inhibition assays were performed to characterize the drugs. Heterotopic Brown Norway-Lewis heart transplantations were performed to study acute cardiac allograft rejection, graft survival, suppression of cellular host responsiveness, and antibody production. Therapeutic and subtherapeutic doses of R507 (60 and 15 mg/kg 2 times per day) and R545 (20 and 5 mg/kg 2 times per day) were compared with those of tacrolimus (Tac; 4 and 1 mg/kg once per day). Plasma levels of R507 and R545 were sustained high for several hours. Cell-based enzyme assays showed selective inhibition of JAK1/3-dependent pathways with 20-fold or greater selectivity over JAK2 and Tyrosine kinase 2 kinases. After heart transplantation, both JAK1/3 inhibitors reduced early mononuclear graft infiltration, even significantly more potent than Tac. Intragraft interferon-γ release was significantly reduced by R507 and R545, and for interleukin-10 suppression, they were even significantly more potent than Tac. Both JAK1/3 inhibitors and Tac were similarly effective in reducing the host Th1 and Th2, but not Th17, responsiveness and similarly prevented donor-specific immunoglobulin M antibody production. Subtherapeutic and therapeutic R507 and R545 doses prolonged the mean graft survival and were similarly effective as 1 and 4 mg/kg Tac, respectively. In combination regimens, however, only R507 showed highly beneficial synergistic drug interactions with Tac. Both R507 and R545 are potent novel immunosuppressants with favorable pharmacokinetics and high JAK1/3 selectivity, but only R507 synergistically interacts with Tac.

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

Discovery of aminofurazan-azabenzimidazoles as inhibitors of Rho-kinase with high kinase selectivity and antihypertensive activity.

PubMed

Stavenger, Robert A; Cui, Haifeng; Dowdell, Sarah E; Franz, Robert G; Gaitanopoulos, Dimitri E; Goodman, Krista B; Hilfiker, Mark A; Ivy, Robert L; Leber, Jack D; Marino, Joseph P; Oh, Hye-Ja; Viet, Andrew Q; Xu, Weiwei; Ye, Guosen; Zhang, Daohua; Zhao, Yongdong; Jolivette, Larry J; Head, Martha S; Semus, Simon F; Elkins, Patricia A; Kirkpatrick, Robert B; Dul, Edward; Khandekar, Sanjay S; Yi, Tracey; Jung, David K; Wright, Lois L; Smith, Gary K; Behm, David J; Doe, Christopher P; Bentley, Ross; Chen, Zunxuan X; Hu, Erding; Lee, Dennis

2007-01-11

The discovery, proposed binding mode, and optimization of a novel class of Rho-kinase inhibitors are presented. Appropriate substitution on the 6-position of the azabenzimidazole core provided subnanomolar enzyme potency in vitro while dramatically improving selectivity over a panel of other kinases. Pharmacokinetic data was obtained for the most potent and selective examples and one (6n) has been shown to lower blood pressure in a rat model of hypertension.

Structure-Based Discovery of 4-(6-Methoxy-2-methyl-4-(quinolin-4-yl)-9 H -pyrimido[4,5- b ]indol-7-yl)-3,5-dimethylisoxazole (CD161) as a Potent and Orally Bioavailable BET Bromodomain Inhibitor

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

Zhao, Yujun; Bai, Longchuan; Liu, Liu

We have designed and synthesized 9H-pyrimido[4,5-b]indole-containing compounds to obtain potent and orally bioavailable BET inhibitors. By incorporation of an indole or a quinoline moiety to the 9H-pyrimido[4,5-b]indole core, we identified a series of small molecules showing high binding affinities to BET proteins and low nanomolar potencies in inhibition of cell growth in acute leukemia cell lines. One such compound, 4-(6-methoxy-2-methyl-4-(quinolin-4-yl)-9H-pyrimido[4,5-b]indol-7-yl)-3,5-dimethylisoxazole (31) has excellent microsomal stability and good oral pharmacokinetics in rats and mice. Orally administered, 31 achieves significant antitumor activity in the MV4;11 leukemia and MDA-MB-231 triple-negative breast cancer xenograft models in mice. Determination of the cocrystal structure of 31more » with BRD4 BD2 provides a structural basis for its high binding affinity to BET proteins. Testing its binding affinities against other bromodomain-containing proteins shows that 31 is a highly selective inhibitor of BET proteins. Our data show that 31 is a potent, selective, and orally active BET inhibitor.« less

Optimization of Substituted 6-Salicyl-4-Anilinoquinazoline Derivatives as Dual EGFR/HER2 Tyrosine Kinase Inhibitors

PubMed Central

Sun, Jian; Li, Jing-Ran; Fang, Fei; Du, Qian-Ru; Qian, Yong; Gong, Hai-Bin; Zhu, Hai-Liang

2013-01-01

4-Anilinoquinazolines as an important class of protein kinase inhibitor are widely investigated for epidermal growth factor receptor (EGFR) tyrosine kinase or epidermal growth factor receptor 2 (HER2) inhibition. A series of novel 6-salicyl-4-anilinoquinazoline derivatives 9–27 were prepared and evaluated for their EGFR/HER2 tyrosine kinase inhibitory activity as well as their antiproliferative properties on three variant cancer cell lines (A431, MCF-7, and A549). The bioassay results showed most of the designed compounds exhibited moderate to potent in vitro inhibitory activity in the enzymatic and cellular assays, of which compound 21 revealed the most potent dual EGFR/HER2 inhibitory activity, with IC50 values of 0.12 µM and 0.096 µM, respectively, comparable to the control compounds Erlotinib and Lapatinib. Furthermore, the kinase selectivity profile of 21 was accessed and demonstrated its good selectivity over the majority of the close kinase targets. Docking simulation was performed to position compound 21 into the EGFR/HER2 active site to determine the probable binding pose. These new findings along with molecular docking observations could provide an important basis for further development of compound 21 as a potent EGFR/HER2 dual kinase inhibitor. PMID:23936329

Transfer of genetic therapy across human populations: molecular targets for increasing patient coverage in repeat expansion diseases

PubMed Central

Varela, Miguel A; Curtis, Helen J; Douglas, Andrew GL; Hammond, Suzan M; O'Loughlin, Aisling J; Sobrido, Maria J; Scholefield, Janine; Wood, Matthew JA

2016-01-01

Allele-specific gene therapy aims to silence expression of mutant alleles through targeting of disease-linked single-nucleotide polymorphisms (SNPs). However, SNP linkage to disease varies between populations, making such molecular therapies applicable only to a subset of patients. Moreover, not all SNPs have the molecular features necessary for potent gene silencing. Here we provide knowledge to allow the maximisation of patient coverage by building a comprehensive understanding of SNPs ranked according to their predicted suitability toward allele-specific silencing in 14 repeat expansion diseases: amyotrophic lateral sclerosis and frontotemporal dementia, dentatorubral-pallidoluysian atrophy, myotonic dystrophy 1, myotonic dystrophy 2, Huntington's disease and several spinocerebellar ataxias. Our systematic analysis of DNA sequence variation shows that most annotated SNPs are not suitable for potent allele-specific silencing across populations because of suboptimal sequence features and low variability (>97% in HD). We suggest maximising patient coverage by selecting SNPs with high heterozygosity across populations, and preferentially targeting SNPs that lead to purine:purine mismatches in wild-type alleles to obtain potent allele-specific silencing. We therefore provide fundamental knowledge on strategies for optimising patient coverage of therapeutics for microsatellite expansion disorders by linking analysis of population genetic variation to the selection of molecular targets. PMID:25990798

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

In vitro and in vivo antiviral activity of 2'-fluorinated arabinosides of 5-(2-haloalkyl)uracil.

PubMed

Rosenwirth, B; Streicher, W; De Clercq, E; Wanek, E; Schwarz, W; Griengl, H

1987-06-01

5-(2-Fluoroethyl)-2'-deoxyuridine (FEDU), its 2'-fluoroarabinofuranosyl analog (FEFAU) and the 2'-fluoroarabinofuranosyl analog (CEFAU) of the potent anti-herpesvirus compound 5-(2-chloroethyl)-2'-deoxyuridine (CEDU) were evaluated for activity against herpes simplex virus type 1 (HSV-1) and HSV-2 in vitro and in vivo. FEDU, FEFAU and CEFAU proved to be potent and selective anti-herpesvirus agents in vitro. Their potency is evident from their low minimum inhibitory concentrations for HSV-1 and HSV-2, and their selectivity is attested by the marginal inhibition of cell proliferation at relatively high concentrations, and by the high concentrations at which DNA-, RNA- or protein synthesis in normal uninfected host cells is inhibited. Their activity spectrum is broader than that of CEDU: in addition to being highly effective against HSV-1 replication, these derivatives, in particular FEFAU, inhibit HSV-2 replication at concentrations comparable to acyclovir (ACV). In the systemic and cutaneous HSV-1 infection models in mice, FEDU, FEFAU and CEFAU were markedly less potent than CEDU in suppressing the development of lesions and in reducing the mortality rate. In HSV-2 infections in mice and in guinea pigs FEDU, FEFAU and CEFAU were virtually ineffective. CEDU, however, exerted a protective effect in these animal models, albeit at relatively high concentrations.

Transfer of genetic therapy across human populations: molecular targets for increasing patient coverage in repeat expansion diseases.

PubMed

Varela, Miguel A; Curtis, Helen J; Douglas, Andrew G L; Hammond, Suzan M; O'Loughlin, Aisling J; Sobrido, Maria J; Scholefield, Janine; Wood, Matthew J A

2016-02-01

Allele-specific gene therapy aims to silence expression of mutant alleles through targeting of disease-linked single-nucleotide polymorphisms (SNPs). However, SNP linkage to disease varies between populations, making such molecular therapies applicable only to a subset of patients. Moreover, not all SNPs have the molecular features necessary for potent gene silencing. Here we provide knowledge to allow the maximisation of patient coverage by building a comprehensive understanding of SNPs ranked according to their predicted suitability toward allele-specific silencing in 14 repeat expansion diseases: amyotrophic lateral sclerosis and frontotemporal dementia, dentatorubral-pallidoluysian atrophy, myotonic dystrophy 1, myotonic dystrophy 2, Huntington's disease and several spinocerebellar ataxias. Our systematic analysis of DNA sequence variation shows that most annotated SNPs are not suitable for potent allele-specific silencing across populations because of suboptimal sequence features and low variability (>97% in HD). We suggest maximising patient coverage by selecting SNPs with high heterozygosity across populations, and preferentially targeting SNPs that lead to purine:purine mismatches in wild-type alleles to obtain potent allele-specific silencing. We therefore provide fundamental knowledge on strategies for optimising patient coverage of therapeutics for microsatellite expansion disorders by linking analysis of population genetic variation to the selection of molecular targets.

De novo design and synthesis of ultra-short peptidomimetic antibiotics having dual antimicrobial and anti-inflammatory activities.

PubMed

Murugan, Ravichandran N; Jacob, Binu; Ahn, Mija; Hwang, Eunha; Sohn, Hoik; Park, Hyo-Nam; Lee, Eunjung; Seo, Ji-Hyung; Cheong, Chaejoon; Nam, Ky-Youb; Hyun, Jae-Kyung; Jeong, Ki-Woong; Kim, Yangmee; Shin, Song Yub; Bang, Jeong Kyu

2013-01-01

Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability. In an attempt to overcome the issues described above, a set of ultra-short, His-derived antimicrobial peptides (HDAMPs) has been developed for the first time. Through systematic tuning of pendant hydrophobic alkyl tails at the N(π)- and N(τ)-positions on His, and the positive charge of Arg, much higher prokaryotic selectivity was achieved, compared to human AMP LL-37. Additionally, the most potent HDAMPs showed promising dual antimicrobial and anti-inflammatory activities, as well as anti-methicillin-resistant Staphylococcus aureus (MRSA) activity and proteolytic resistance. Our results from transmission electron microscopy, membrane depolarization, confocal laser-scanning microscopy, and calcein-dye leakage experiments propose that HDAMP-1 kills microbial cells via dissipation of the membrane potential by forming pore/ion channels on bacterial cell membranes. The combination of the ultra-short size, high-prokaryotic selectivity, potent anti-MRSA activity, anti-inflammatory activity, and proteolytic resistance of the designed HDAMP-1, -3, -5, and -6 makes these molecules promising candidates for future antimicrobial therapeutics.

JB-9322, a new selective histamine H2-receptor antagonist with potent gastric mucosal protective properties.

PubMed

Palacios, B; Montero, M J; Sevilla, M A; Román, L S

1995-05-01

1. JB-9322 is a selective histamine H2-receptor antagonist with gastric antisecretory activity and mucosal protective properties. 2. The affinity of JB-9322 for the guinea-pig atria histamine H2-receptor was approximately 2 times greater than that of ranitidine. 3. In vivo, the ID50 value for the inhibition of gastric acid secretion in pylorus-ligated rats was 5.28 mg kg-1 intraperitoneally. JB-9322 also dose-dependently inhibited gastric juice volume and pepsin secretion. In gastric lumen-perfused rats, intravenous injection of JB-9322 dose-dependently reduced histamine-, pentagastrin- and carbachol-stimulated gastric acid secretion. 4. JB-9322 showed antiulcer activity against aspirin and indomethacin-induced gastric lesions and was more potent than ranitidine. 5. JB-9322 effectively inhibited macroscopic gastric haemorrhagic lesions induced by ethanol. Intraperitoneal injection was effective in preventing the lesions as well as oral treatment. The oral ID50 value for these lesions was 1.33 mg kg-1. By contrast, ranitidine (50 mg kg-1) failed to reduce these lesions. In addition, the protective effect of JB-9322 was independent of prostaglandin synthesis. 6. These results indicate that JB-9322 is a new antiulcer drug that exerts a potent cytoprotective effect in addition to its gastric antisecretory activity.

Toxic ligand conjugates as tools in the study of receptor-ligand interactions.

PubMed

Herschman, H R; Simpson, D L; Cawley, D B

1982-01-01

We have constructed hybrid proteins in which the toxic A chains of ricin or diptheria toxin have been linked to either asialofetuin, fetuin, or epidermal growth factor (EGF). Both ASF-RTA and ASF-DTA are potent toxins on cultured rat hepatocytes, cells that display the asialoglycoprotein receptor. Toxicity of these two compounds is restricted to hepatocytes and can be blocked by asialoglycoproteins but not the native glycoproteins or asialoagalactoglycoprotein derivatives, indicating that the toxicity of the conjugates is mediated by the hepatic asialoglycoprotein receptor. The EGF-RTA conjugate is an extremely potent toxin on cells that can bind the hormone, but is only poorly effective on cells that are unable to bind EGF. The EGF-DTA conjugate, in contrast, is unable to kill 3T3 cells and is at least two orders of magnitude less effective than EGF-RTA on A431 cells, a cell line with 1-2 X 10(6) EGF receptors per cell. However, when EGF-RTA and EGF-DTA were tested on primary liver hepatocyte cultures, which were susceptible to both ASF-RTA and ASF-DTA, both EGF conjugates were potent toxins. Sensitivity of the hepatocyte cultures to ricin toxicity increases slightly during a 52-hr culture period. In contrast, sensitivity to EGF-RTA and ASF-RTA decline dramatically during this period. Receptors for both ligands remain plentiful on the cell surface during this time.

Design of novel neurokinin 1 receptor antagonists based on conformationally constrained aromatic amino acids and discovery of a potent chimeric opioid agonist-neurokinin 1 receptor antagonist

PubMed Central

Ballet, Steven; Feytens, Debby; Buysse, Koen; Chung, Nga N.; Lemieux, Carole; Tumati, Suneeta; Keresztes, Attila; Van Duppen, Joost; Lai, Josephine; Varga, Eva; Porreca, Frank; Schiller, Peter W.; Broeck, Jozef Vanden; Tourwé, Dirk

2011-01-01

A screening of conformationally constrained aromatic amino acids as base cores for the preparation of new NK1 receptor antagonists resulted in the discovery of three new NK1 receptor antagonists, 19 [Ac-Aba-Gly-NH-3′,5′-(CF3)2-Bn], 20 [Ac-Aba-Gly-NMe-3′,5′-(CF3)2-Bn] and 23 [Ac-Tic-NMe-3′,5′-(CF3)2-Bn], which were able to counteract the agonist effect of substance P, the endogenous ligand of NK1R. The most active NK1 antagonist of the series, 20 [Ac-Aba-Gly-NMe-3′,5′-(CF3)2-Bn], was then used in the design of a novel, potent chimeric opioid agonist-NK1 receptor antagonist, 35 [Dmt-D-Arg-Aba-Gly-NMe-3′,5′-(CF3)2-Bn], which combines the N-terminus of the established Dmt1-DALDA agonist opioid pharmacophore (H-Dmt-D-Arg-Phe-Lys-NH2) and 20, the NK1R ligand. The opioid component of the chimeric compound 35, i.e. Dmt-D-Arg-Aba-Gly-NH2 36, also proved to be an extremely potent and balanced μ- and δ opioid receptor agonist with subnanomolar binding and in vitro functional activity. PMID:21413804

Design and Synthesis of a Pan-Janus Kinase Inhibitor Clinical Candidate (PF-06263276) Suitable for Inhaled and Topical Delivery for the Treatment of Inflammatory Diseases of the Lungs and Skin

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

Jones, Peter; Storer, R. Ian; Sabnis, Yogesh A.

By use of a structure-based computational method for identification of structurally novel Janus kinase (JAK) inhibitors predicted to bind beyond the ATP binding site, a potent series of indazoles was identified as selective pan-JAK inhibitors with a type 1.5 binding mode. Optimization of the series for potency and increased duration of action commensurate with inhaled or topical delivery resulted in potent pan-JAK inhibitor 2 (PF-06263276), which was advanced into clinical studies.

Potent μ-Opioid Receptor Agonists from Cyclic Peptides Tyr-c[D-Lys-Xxx-Tyr-Gly]: Synthesis, Biological, and Structural Evaluation.

PubMed

Li, Yangmei; Cazares, Margret; Wu, Jinhua; Houghten, Richard A; Toll, Laurence; Dooley, Colette

2016-02-11

To optimize the structure of a μ-opioid receptor ligand, analogs H-Tyr-c[D-Lys-Xxx-Tyr-Gly] were synthesized and their biological activity was tested. The analog containing a Phe(3) was identified as not only exhibiting binding affinity 14-fold higher than the original hit but also producing agonist activity 3-fold more potent than morphine. NMR study suggested that a trans conformation at D-Lys(2)-Xxx(3) is crucial for these cyclic peptides to maintain high affinity, selectivity, and functional activity toward the μ-opioid receptor.

Phorbol Ester Effects on Neurotransmission: Interaction with Neurotransmitters and Calcium in Smooth Muscle

NASA Astrophysics Data System (ADS)

Baraban, Jay M.; Gould, Robert J.; Peroutka, Stephen J.; Snyder, Solomon H.

1985-01-01

Stimulation of the phosphatidylinositol cycle by neurotransmitters generates diacylglycerol, an activator of protein kinase C, which may regulate some forms of neurotransmission. Phorbol esters, potent inflammatory and tumorpromoting compounds, also activate protein kinase C. We demonstrate potent and selective effects of phorbol esters on smooth muscle, indicating a role for protein kinase C in neurotransmission. In rat vas deferens and dog basilar artery, phorbol esters synergize with calcium to mimic the contractile effects of neurotransmitters that act through the phosphatidylinositol cycle. In guinea pig ileum and rat uterus, phorbol esters block contractions produced by these neurotransmitters.

Sansanmycin natural product analogues as potent and selective anti-mycobacterials that inhibit lipid I biosynthesis

PubMed Central

Tran, Anh T.; Watson, Emma E.; Pujari, Venugopal; Conroy, Trent; Dowman, Luke J.; Giltrap, Andrew M.; Pang, Angel; Wong, Weng Ruh; Linington, Roger G.; Mahapatra, Sebabrata; Saunders, Jessica; Charman, Susan A.; West, Nicholas P.; Bugg, Timothy D. H.; Tod, Julie; Dowson, Christopher G.; Roper, David I.; Crick, Dean C.; Britton, Warwick J.; Payne, Richard J.

2017-01-01

Tuberculosis (TB) is responsible for enormous global morbidity and mortality, and current treatment regimens rely on the use of drugs that have been in use for more than 40 years. Owing to widespread resistance to these therapies, new drugs are desperately needed to control the TB disease burden. Herein, we describe the rapid synthesis of analogues of the sansanmycin uridylpeptide natural products that represent promising new TB drug leads. The compounds exhibit potent and selective inhibition of Mycobacterium tuberculosis, the etiological agent of TB, both in vitro and intracellularly. The natural product analogues are nanomolar inhibitors of Mtb phospho-MurNAc-pentapeptide translocase, the enzyme responsible for the synthesis of lipid I in mycobacteria. This work lays the foundation for the development of uridylpeptide natural product analogues as new TB drug candidates that operate through the inhibition of peptidoglycan biosynthesis. PMID:28248311

The evolution of the matrix metalloproteinase inhibitor drug discovery program at abbott laboratories.

PubMed

Wada, Carol K

2004-01-01

Matrix metalloproteinases (MMPs) have been implicated in several pathologies. At Abbott Laboratories, the matrix metalloproteinases inhibitor drug discovery program has focused on the discovery of a potent, selective, orally bioavailable MMP inhibitor for the treatment of cancer. The program evolved from early succinate-based inhibitors to utilizing in-house technology such as SAR by NMR to develop a novel class of biaryl hydroxamate MMP inhibitors. The metabolic instability of the biaryl hydroxamates led to the discovery of a new class of N-formylhydroxylamine (retrohydroxamate) biaryl ethers, exemplified by ABT-770 (16). Toxicity issues with this pre-clinical candidate led to the discovery of another novel class of retrohydroxamate MMP inhibitors, the phenoxyphenyl sulfones such as ABT-518 (19j). ABT-518 is a potent, orally bioavailable, selective inhibitor of MMP-2 and 9 over MMP-1 that has been evaluated in Phase I clinical trials in cancer patients.

Sansanmycin natural product analogues as potent and selective anti-mycobacterials that inhibit lipid I biosynthesis

NASA Astrophysics Data System (ADS)

Tran, Anh T.; Watson, Emma E.; Pujari, Venugopal; Conroy, Trent; Dowman, Luke J.; Giltrap, Andrew M.; Pang, Angel; Wong, Weng Ruh; Linington, Roger G.; Mahapatra, Sebabrata; Saunders, Jessica; Charman, Susan A.; West, Nicholas P.; Bugg, Timothy D. H.; Tod, Julie; Dowson, Christopher G.; Roper, David I.; Crick, Dean C.; Britton, Warwick J.; Payne, Richard J.

2017-03-01

Tuberculosis (TB) is responsible for enormous global morbidity and mortality, and current treatment regimens rely on the use of drugs that have been in use for more than 40 years. Owing to widespread resistance to these therapies, new drugs are desperately needed to control the TB disease burden. Herein, we describe the rapid synthesis of analogues of the sansanmycin uridylpeptide natural products that represent promising new TB drug leads. The compounds exhibit potent and selective inhibition of Mycobacterium tuberculosis, the etiological agent of TB, both in vitro and intracellularly. The natural product analogues are nanomolar inhibitors of Mtb phospho-MurNAc-pentapeptide translocase, the enzyme responsible for the synthesis of lipid I in mycobacteria. This work lays the foundation for the development of uridylpeptide natural product analogues as new TB drug candidates that operate through the inhibition of peptidoglycan biosynthesis.

Cytotoxic 2',5'-dihydroxychalcones with unexpected antiangiogenic activity.

PubMed

Nam, Nguyen-Hai; Kim, Yong; You, Young-Jae; Hong, Dong-Ho; Kim, Hwan-Mook; Ahn, Byung-Zun

2003-02-01

A series of 2',5'-dihydroxychalcones were synthesized and evaluated for cytotoxicity against tumor cell lines and human umbilical venous endothelial cells (HUVEC). It was found that chalcones with electron-withdrawing substituents on the B ring exhibited potent cytotoxicity against a variety of tumor cell lines while compounds with electron-releasing groups were less potent in general. Those compounds with B ring replaced by extended or heteroaromatic rings exhibited significant bioactivity. Several compounds were shown to have marked cytotoxic selectivity towards HUVECs. Especially, among the synthesized compounds, 2-chloro-2',5'-dihydroxychalcone (2-3) showed the highest selectivity index up to 66 in comparison to HCT116 cells. This compound also exhibited strong inhibitory effects on the HUVEC tube formation in an in vitro model. When administered into BDF1 mice bearing Lewis lung carcinoma cells at 50 mg kg(-1) day(-1), 2-3 was found to inhibit the growth of tumor mass by 60.5%.

Synthetic Studies of Neoclerodane Diterpenes from Salvia divinorum: Identification of a Potent and Centrally Acting μ Opioid Analgesic with Reduced Abuse Liability.

PubMed

Crowley, Rachel Saylor; Riley, Andrew P; Sherwood, Alexander M; Groer, Chad E; Shivaperumal, Nirajmohan; Biscaia, Miguel; Paton, Kelly; Schneider, Sebastian; Provasi, Davide; Kivell, Bronwyn M; Filizola, Marta; Prisinzano, Thomas E

2016-12-22

Opioids are widely used to treat millions suffering from pain, but their analgesic utility is limited due to associated side effects. Herein we report the development and evaluation of a chemical probe exhibiting analgesia and reduced opioid-induced side effects. This compound, kurkinorin (5), is a potent and selective μ-opioid receptor (MOR) agonist (EC 50 = 1.2 nM, >8000 μ/κ selectivity). 5 is a biased activator of MOR-induced G-protein signaling over β-arrestin-2 recruitment. Metadynamics simulations of 5's binding to a MOR crystal structure suggest energetically preferred binding modes that differ from crystallographic ligands. In vivo studies with 5 demonstrate centrally mediated antinociception, significantly reduced rewarding effects, tolerance, and sedation. We propose that this novel MOR agonist may represent a valuable tool in distinguishing the pathways involved in MOR-induced analgesia from its side effects.

Structure-Based Approach to the Development of Potent and Selective Inhibitors of Dihydrofolate Reductase from Cryptosporidium

PubMed Central

Bolstad, David B.; Bolstad, Erin S. D.; Frey, Kathleen M.; Wright, Dennis L.; Anderson, Amy C.

2008-01-01

Cryptosporidiosis is an emerging infectious disease that can be life-threatening in an immune-compromised individual and causes gastrointestinal distress lasting up to 2 weeks in an immune-competent individual. There are few therapeutics available for effectively treating this disease. We have been exploring dihydrofolate reductase (DHFR) as a potential target in Cryptosporidium. On the basis of the structure of the DHFR enzyme from C. hominis, we have developed a novel scaffold that led to the discovery of potent (38 nM) and efficient inhibitors of this enzyme. Recently, we have advanced these inhibitors to the next stage of development. Using the structures of both the protozoal and human enzymes, we have developed inhibitors with nanomolar potency (1.1 nM) against the pathogenic enzyme and high levels (1273-fold) of selectivity over the human enzyme. PMID:18834108

Extreme habitats as refuge from parasite infections? Evidence from an extremophile fish

NASA Astrophysics Data System (ADS)

Tobler, Michael; Schlupp, Ingo; García de León, Francisco J.; Glaubrecht, Matthias; Plath, Martin

2007-05-01

Living in extreme habitats typically requires costly adaptations of any organism tolerating these conditions, but very little is known about potential benefits that trade off these costs. We suggest that extreme habitats may function as refuge from parasite infections, since parasites can become locally extinct either directly, through selection by an extreme environmental parameter on free-living parasite stages, or indirectly, through selection on other host species involved in its life cycle. We tested this hypothesis in a small freshwater fish, the Atlantic molly ( Poecilia mexicana) that inhabits normal freshwaters as well as extreme habitats containing high concentrations of toxic hydrogen sulfide. Populations from such extreme habitats are significantly less parasitized by the trematode Uvulifer sp. than a population from a non-sulfidic habitat. We suggest that reduced parasite prevalence may be a benefit of living in sulfidic habitats.

Synthesis and biological activity evaluation of cytidine-5'-deoxy-5-fluoro-N-[(alkoxy/aryloxy)] carbonyl-cyclic 2',3'-carbonates.

PubMed

Jhansi Rani, V; Raghavendra, A; Kishore, P; Nanda Kumar, Y; Hema Kumar, K; Jagadeeswarareddy, K

2012-08-01

Capecitabine, an oral prodrug of 5-FU was developed to improve the tumor selectivity and tolerability. To enhance the efficacy of capacitabine, a series of 5'-deoxy-5-fluorocytidine derivatives 5a-e were synthesized. In the present study, we investigated antitumor activity of 5'-deoxy-5-fluorocytidine derivatives both in vivo and in vitro methods. Title compounds were non-mutagenic to Salmonella typhimurium tester strain in Ames test. Compounds 5d and 5e are potent to inhibit the proliferation of NCI-69, PZ-HPV-7, MCF-7 and HeLa cells in MTT assay. In particular, 5d and 5e showed potent antitumor activities against L1210 leukemia cell line. Collectively, these findings suggest that 5d and 5e are more potent anti-cancer compounds than capecitabine. Published by Elsevier Masson SAS.

Recent progress of the development of dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes mellitus.

PubMed

Li, Ning; Wang, Li-Jun; Jiang, Bo; Li, Xiang-Qian; Guo, Chuan-Long; Guo, Shu-Ju; Shi, Da-Yong

2018-05-10

Diabetes is a fast growing chronic metabolic disorder around the world. Dipeptidyl peptidase-4 (DPP-4) is a new promising target during type 2 diabetes glycemic control. Thus, a number of potent DPP-4 inhibitors were developed and play a rapidly evolving role in the management of type 2 diabetes in recent years. This article reviews the development of synthetic and natural DPP-4 inhibitors from 2012 to 2017 and provides their physico-chemical properties, biological activities against DPP-4 and selectivity over dipeptidyl peptidase-8/9. Moreover, the glucose-lowering mechanisms and the active site of DPP-4 are also discussed. We also discuss strategies and structure-activity relationships for identifying potent DPP-4 inhibitors, which will provide useful information for developing potent DPP-4 drugs as type 2 diabtes treatments. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Novel inhibitors of the Gardos channel for the treatment of sickle cell disease.

PubMed

McNaughton-Smith, Grant A; Burns, J Ford; Stocker, Jonathan W; Rigdon, Gregory C; Creech, Christopher; Arrington, Susan; Shelton, Tara; de Franceschi, Lucia

2008-02-28

Sickle cell disease (SCD) is a hereditary condition characterized by deformation of red blood cells (RBCs). This phenomenon is due to the presence of abnormal hemoglobin that polymerizes upon deoxygenation. This effect is exacerbated when dehydrated RBCs experience a loss of both water and potassium salts. One critical pathway for the regulation of potassium efflux from RBCs is the Gardos channel, a calcium-activated potassium channel. This paper describes the synthesis and biological evaluation of a series of potent inhibitors of the Gardos channel. The goal was to identify compounds that were potent and selective inhibitors of the channel but had improved pharmacokinetic properties compared to 1, Clotrimazole. Several triarylamides such as 10 and 21 were potent inhibitors of the Gardos channel (IC50 of <10 nM) and active in a mouse model of SCD. Compound 21 (ICA-17043) was advanced into phase 3 clinical trials for SCD.

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.

Discovery of potent NEK2 inhibitors as potential anticancer agents using structure-based exploration of NEK2 pharmacophoric space coupled with QSAR analyses.

PubMed

Khanfar, Mohammad A; Banat, Fahmy; Alabed, Shada; Alqtaishat, Saja

2017-02-01

High expression of Nek2 has been detected in several types of cancer and it represents a novel target for human cancer. In the current study, structure-based pharmacophore modeling combined with multiple linear regression (MLR)-based QSAR analyses was applied to disclose the structural requirements for NEK2 inhibition. Generated pharmacophoric models were initially validated with receiver operating characteristic (ROC) curve, and optimum models were subsequently implemented in QSAR modeling with other physiochemical descriptors. QSAR-selected models were implied as 3D search filters to mine the National Cancer Institute (NCI) database for novel NEK2 inhibitors, whereas the associated QSAR model prioritized the bioactivities of captured hits for in vitro evaluation. Experimental validation identified several potent NEK2 inhibitors of novel structural scaffolds. The most potent captured hit exhibited an [Formula: see text] value of 237 nM.

Using Extreme Groups Strategy When Measures Are Not Normally Distributed.

ERIC Educational Resources Information Center

Fowler, Robert L.

1992-01-01

A Monte Carlo simulation explored how to optimize power in the extreme groups strategy when sampling from nonnormal distributions. Results show that the optimum percent for the extreme group selection was approximately the same for all population shapes, except the extremely platykurtic (uniform) distribution. (SLD)

The Power to Detect Linkage Disequilibrium with Quantitative Traits in Selected Samples

PubMed Central

Abecasis, Gonçalo R.; Cookson, William O. C.; Cardon, Lon R.

2001-01-01

Results from power studies for linkage detection have led to many ongoing and planned collections of phenotypically extreme nuclear families. Given the great expense of collecting these families and the imminent availability of a dense diallelic marker map, the families are likely to be used in allelic-association as well as linkage studies. However, optimal selection strategies for linkage may not be equally powerful for association. We examine the power to detect linkage disequilibrium for quantitative traits after phenotypic selection. The results encompass six selection strategies that are in widespread use, including single selection (two designs), affected sib pairs, concordant and discordant pairs, and the extreme-concordant and -discordant design. Selection of sibships on the basis of one extreme proband with high or low trait scores provides as much power as discordant sib pairs but requires the screening and phenotyping of substantially fewer initial families from which to select. Analysis of the role of allele frequencies within each selection design indicates that common trait alleles generally offer the most power, but similarities between the marker- and trait-allele frequencies are much more important than the trait-locus frequency alone. Some of the most widespread selection designs, such as single selection, yield power gains only when both the marker and quantitative trait loci (QTL) are relatively rare in the population. In contrast, discordant pairs and the extreme-proband design provide power for the broadest range of QTL–marker-allele frequency differences. Overall, proband selection from either tail provides the best balance of power, robustness, and simplicity of ascertainment for family-based association analysis. PMID:11349228

Potent and selective alpha-ketoheterocycle-based inhibitors of the anandamide and oleamide catabolizing enzyme, fatty acid amide hydrolase.

PubMed

Romero, F Anthony; Du, Wu; Hwang, Inkyu; Rayl, Thomas J; Kimball, F Scott; Leung, Donmienne; Hoover, Heather S; Apodaca, Richard L; Breitenbucher, J Guy; Cravatt, Benjamin F; Boger, Dale L

2007-03-08

A study of the structure-activity relationships (SAR) of 2f (OL-135), a potent inhibitor of fatty acid amide hydrolase (FAAH), is detailed, targeting the 5-position of the oxazole. Examination of a series of substituted benzene derivatives (12-14) revealed that the optimal position for substitution was the meta-position with selected members approaching or exceeding the potency of 2f. Concurrent with these studies, the effect of substitution on the pyridine ring of 2f was also examined. A series of small, nonaromatic C5-substituents was also explored and revealed that the K(i) follows a well-defined correlation with the Hammett sigma(p) constant (rho = 3.01, R2 = 0.91) in which electron-withdrawing substituents enhance potency, leading to inhibitors with K(i)s as low as 400 pM (20n). Proteomic-wide screening of the inhibitors revealed that most are exquisitely selective for FAAH over all other mammalian proteases, reversing the 100-fold preference of 20a (C5 substituent = H) for the enzyme TGH.

Epistatic mutations in PUMA BH3 drive an alternate binding mode to potently and selectively inhibit anti-apoptotic Bfl-1

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

Jenson, Justin M.; Ryan, Jeremy A.; Grant, Robert A.

Overexpression of anti-apoptotic Bcl-2 family proteins contributes to cancer progression and confers resistance to chemotherapy. Small molecules that target Bcl-2 are used in the clinic to treat leukemia, but tight and selective inhibitors are not available for Bcl-2 paralog Bfl-1. Guided by computational analysis, we designed variants of the native BH3 motif PUMA that are > 150-fold selective for Bfl-1 binding. The designed peptides potently trigger disruption of the mitochondrial outer membrane in cells dependent on Bfl-1, but not in cells dependent on other anti-apoptotic homologs. High-resolution crystal structures show that designed peptide FS2 binds Bfl-1 in a shifted geometry,more » relative to PUMA and other binding partners, due to a set of epistatic mutations. FS2 modified with an electrophile reacts with a cysteine near the peptide-binding groove to augment specificity. Designed Bfl-1 binders provide reagents for cellular profiling and leads for developing enhanced and cell-permeable peptide or small-molecule inhibitors.« less

Synthetic and structural studies on syringolin A and B reveal critical determinants of selectivity and potency of proteasome inhibition

PubMed Central

Clerc, Jérôme; Groll, Michael; Illich, Damir J.; Bachmann, André S.; Huber, Robert; Schellenberg, Barbara; Dudler, Robert; Kaiser, Markus

2009-01-01

Syrbactins, a family of natural products belonging either to the syringolin or glidobactin class, are highly potent proteasome inhibitors. Although sharing similar structural features, they differ in their macrocyclic lactam core structure and exocyclic side chain. These structural variations critically influence inhibitory potency and proteasome subsite selectivity. Here, we describe the total synthesis of syringolin A and B, which together with enzyme kinetic and structural studies, allowed us to elucidate the structural determinants underlying the proteasomal subsite selectivity and binding affinity of syrbactins. These findings were used successfully in the rational design and synthesis of a syringolin A-based lipophilic derivative, which proved to be the most potent syrbactin-based proteasome inhibitor described so far. With a Ki′ of 8.65 ± 1.13 nM for the chymotryptic activity, this syringolin A derivative displays a 100-fold higher potency than the parent compound syringolin A. In light of the medicinal relevance of proteasome inhibitors as anticancer compounds, the present findings may assist in the rational design and development of syrbactin-based chemotherapeutics. PMID:19359491

In Silico Identification of a Novel Hinge-Binding Scaffold for Kinase Inhibitor Discovery.

PubMed

Wang, Yanli; Sun, Yuze; Cao, Ran; Liu, Dan; Xie, Yuting; Li, Li; Qi, Xiangbing; Huang, Niu

2017-10-26

To explore novel kinase hinge-binding scaffolds, we carried out structure-based virtual screening against p38α MAPK as a model system. With the assistance of developed kinase-specific structural filters, we identify a novel lead compound that selectively inhibits a panel of kinases with threonine as the gatekeeper residue, including BTK and LCK. These kinases play important roles in lymphocyte activation, which encouraged us to design novel kinase inhibitors as drug candidates for ameliorating inflammatory diseases and cancers. Therefore, we chemically modified our substituted triazole-class lead compound to improve the binding affinity and selectivity via a "minimal decoration" strategy, which resulted in potent and selective kinase inhibitors against LCK (18 nM) and BTK (8 nM). Subsequent crystallographic experiments validated our design. These rationally designed compounds exhibit potent on-target inhibition against BTK in B cells or LCK in T cells, respectively. Our work demonstrates that structure-based virtual screening can be applied to facilitate the development of novel chemical entities in crowded chemical space in the field of kinase inhibitor discovery.

The marine cytotoxin portimine is a potent and selective inducer of apoptosis.

PubMed

Cuddihy, Sarah L; Drake, Sarah; Harwood, D Tim; Selwood, Andrew I; McNabb, Paul S; Hampton, Mark B

2016-12-01

Portimine is a recently discovered member of a class of marine micro-algal toxins called cyclic imines. In dramatic contrast to related compounds in this toxin class, portimine has very low acute toxicity to mice but is highly cytotoxic to cultured cells. In this study we show that portimine kills human Jurkat T-lymphoma cells and mouse embryonic fibroblasts (MEFs), with LC 50 values of 6 and 2.5 nM respectively. Treated cells displayed rapid caspase activation and phosphatidylserine exposure, indicative of apoptotic cell death. Jurkat cells overexpressing the anti-apoptotic protein Bcl-2 or Bax/Bak knockout MEFs were completely protected from portimine. This protection was apparent even at high concentrations of portimine, with no evidence of necrotic cell death, indicating that portimine is a selective chemical inducer of apoptosis. Treatment of the Bcl-2-overexpressing cells with both portimine and the Bcl-2 inhibitor ABT-737 proved a powerful combination, causing >90 % death. We conclude that portimine is one of the most potent naturally derived inducers of apoptosis to be discovered, and it displays strong selectivity for the induction of apoptotic pathways.

Discovery and structure-activity relationship of (1R)-8-chloro-2,3,4,5-tetrahydro-1-methyl-1H-3-benzazepine (Lorcaserin), a selective serotonin 5-HT2C receptor agonist for the treatment of obesity.

PubMed

Smith, Brian M; Smith, Jeffrey M; Tsai, James H; Schultz, Jeffrey A; Gilson, Charles A; Estrada, Scott A; Chen, Rita R; Park, Douglas M; Prieto, Emily B; Gallardo, Charlemagne S; Sengupta, Dipanjan; Dosa, Peter I; Covel, Jon A; Ren, Albert; Webb, Robert R; Beeley, Nigel R A; Martin, Michael; Morgan, Michael; Espitia, Stephen; Saldana, Hazel R; Bjenning, Christina; Whelan, Kevin T; Grottick, Andrew J; Menzaghi, Frederique; Thomsen, William J

2008-01-24

The synthesis and SAR of a novel 3-benzazepine series of 5-HT2C agonists is described. Compound 7d (lorcaserin, APD356) was identified as one of the more potent and selective compounds in vitro (pEC50 values in functional assays measuring [(3)H]phosphoinositol turnover: 5-HT2C = 8.1; 5-HT2A = 6.8; 5-HT2B = 6.1) and was potent in an acute in vivo rat food intake model upon oral administration (ED50 at 6 h = 18 mg/kg). Lorcaserin was further characterized in a single-dose pharmacokinetic study in rat (t1/2 = 3.7 h; F = 86%) and a 28-day model of weight gain in growing Sprague-Dawley rat (8.5% decrease in weight gain observed at 36 mg/kg b.i.d.). Lorcaserin was selected for further evaluation in clinical trials for the treatment of obesity.

Bispecific small molecule–antibody conjugate targeting prostate cancer

PubMed Central

Kim, Chan Hyuk; Axup, Jun Y.; Lawson, Brian R.; Yun, Hwayoung; Tardif, Virginie; Choi, Sei Hyun; Zhou, Quan; Dubrovska, Anna; Biroc, Sandra L.; Marsden, Robin; Pinstaff, Jason; Smider, Vaughn V.; Schultz, Peter G.

2013-01-01

Bispecific antibodies, which simultaneously target CD3 on T cells and tumor-associated antigens to recruit cytotoxic T cells to cancer cells, are a promising new approach to the treatment of hormone-refractory prostate cancer. Here we report a site-specific, semisynthetic method for the production of bispecific antibody-like therapeutics in which a derivative of the prostate-specific membrane antigen-binding small molecule DUPA was selectively conjugated to a mutant αCD3 Fab containing the unnatural amino acid, p-acetylphenylalanine, at a defined site. Homogeneous conjugates were generated in excellent yields and had good solubility. The efficacy of the conjugate was optimized by modifying the linker structure, relative binding orientation, and stoichiometry of the ligand. The optimized conjugate showed potent and selective in vitro activity (EC50 ∼100 pM), good serum half-life, and potent in vivo activity in prophylactic and treatment xenograft mouse models. This semisynthetic approach is likely to be applicable to the generation of additional bispecific agents using drug-like ligands selective for other cell-surface receptors. PMID:24127589

ST7612AA1, a thioacetate-ω(γ-lactam carboxamide) derivative selected from a novel generation of oral HDAC inhibitors.

PubMed

Giannini, Giuseppe; Vesci, Loredana; Battistuzzi, Gianfranco; Vignola, Davide; Milazzo, Ferdinando M; Guglielmi, Mario Berardino; Barbarino, Marcella; Santaniello, Mosè; Fantò, Nicola; Mor, Marco; Rivara, Silvia; Pala, Daniele; Taddei, Maurizio; Pisano, Claudio; Cabri, Walter

2014-10-23

A systematic study of medicinal chemistry aimed at identifying a new generation of HDAC inhibitors, through the introduction of a thiol zinc-binding group (ZBG) and of an amide-lactam in the ω-position of the polyethylene chain of the vorinostat scaffold, allowed the selection of a new class of potent pan-HDAC inhibitors (pan-HDACis). Simple, highly versatile, and efficient synthetic approaches were used to synthesize a library of these new derivatives, which were then submitted to a screening for HDAC inhibition as well as to a preliminary in vitro assessment of their antiproliferative activity. Molecular docking into HDAC crystal structures suggested a binding mode for these thiol derivatives consistent with the stereoselectivity observed upon insertion of amide-lactam substituents in the ω-position. ST7612AA1 (117), selected as a drug candidate for further development, showed an in vitro activity in the nanomolar range associated with a remarkable in vivo antitumor activity, highly competitive with the most potent HDAC inhibitors, currently under clinical trials. A preliminary study of PK and metabolism is also illustrated.

Epistatic mutations in PUMA BH3 drive an alternate binding mode to potently and selectively inhibit anti-apoptotic Bfl-1

PubMed Central

Jenson, Justin M; Ryan, Jeremy A; Grant, Robert A; Letai, Anthony; Keating, Amy E

2017-01-01

Overexpression of anti-apoptotic Bcl-2 family proteins contributes to cancer progression and confers resistance to chemotherapy. Small molecules that target Bcl-2 are used in the clinic to treat leukemia, but tight and selective inhibitors are not available for Bcl-2 paralog Bfl-1. Guided by computational analysis, we designed variants of the native BH3 motif PUMA that are > 150-fold selective for Bfl-1 binding. The designed peptides potently trigger disruption of the mitochondrial outer membrane in cells dependent on Bfl-1, but not in cells dependent on other anti-apoptotic homologs. High-resolution crystal structures show that designed peptide FS2 binds Bfl-1 in a shifted geometry, relative to PUMA and other binding partners, due to a set of epistatic mutations. FS2 modified with an electrophile reacts with a cysteine near the peptide-binding groove to augment specificity. Designed Bfl-1 binders provide reagents for cellular profiling and leads for developing enhanced and cell-permeable peptide or small-molecule inhibitors. DOI: http://dx.doi.org/10.7554/eLife.25541.001 PMID:28594323

Activation of the endogenous nociceptin system by selective nociceptin receptor agonist SCH 221510 produces antitransit and antinociceptive effect: a novel strategy for treatment of diarrhea-predominant IBS.

PubMed

Fichna, J; Sobczak, M; Mokrowiecka, A; Cygankiewicz, A I; Zakrzewski, P K; Cenac, N; Sałaga, M; Timmermans, J-P; Vergnolle, N; Małecka-Panas, E; Krajewska, W M; Storr, M

2014-11-01

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a functional gastrointestinal (GI) disorder, defined by the presence of loose stools and abdominal pain. In search for a novel anti-IBS-D therapy, here we investigated the nociceptin receptor (NOP)-dependent effects in the GI tract. A novel potent and selective NOP agonist SCH 221510 was used in the study. The effect of NOP activation on mouse intestinal motility was characterized in vitro and in vivo, in physiological conditions and in animal models of hypermotility and diarrhea. Well-established mouse models of visceral pain were used to characterize the antinociceptive effect of the NOP activation. To provide additional evidence that the endogenous nociceptin system is a relevant target for IBS, NOP expression and nociceptin levels were quantified in serum and colonic biopsies from IBS-D patients. SCH 221510 produced a potent NOP-mediated inhibitory effect on mouse intestinal motility in vitro and in vivo in physiological conditions. The NOP agonist displayed an antidiarrheal and analgesic action after oral administration in animal models mimicking the symptoms of IBS-D. Studies on human samples revealed a strong decrease in endogenous nociceptin system expression in IBS-D patients compared with healthy controls. Collectively, mouse and human data suggest that the endogenous nociceptin system is involved in IBS-D and may become a target for anti-IBS-D treatments using potent and selective synthetic NOP agonists. © 2014 John Wiley & Sons Ltd.

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.

Discovery of spiropiperidine-based potent and selective Orexin-2 receptor antagonists.

PubMed

Fujimoto, Tatsuhiko; Tomata, Yoshihide; Kunitomo, Jun; Hirozane, Mariko; Marui, Shogo

2011-11-01

To generate novel human Orexin-2 Receptor (OX2R) antagonists, a spiropiperidine based scaffold was designed and a SAR study was carried out. Compound 4f possessed the highest OX2R antagonistic activity with an IC(50) value of 3nM with 450-fold selectivity against Orexin-1 Receptor (OX1R). Copyright © 2011 Elsevier Ltd. All rights reserved.

Nonclinical and clinical pharmacological characterization of the potent and selective cathepsin K inhibitor MIV-711.

PubMed

Lindström, Erik; Rizoska, Biljana; Henderson, Ian; Terelius, Ylva; Jerling, Markus; Edenius, Charlotte; Grabowska, Urszula

2018-05-09

Cathepsin K is an attractive therapeutic target for diseases in which bone resorption is excessive such as osteoporosis and osteoarthritis (OA). The current paper characterized the pharmacological profile of the potent and selective cathepsin K inhibitor, MIV-711, in vitro and in cynomolgus monkeys, and assessed translation to human based on a single dose clinical study in man. The potency and selectivity of MIV-711 were assessed in vitro using recombinant enzyme assays and differentiated human osteoclasts. MIV-711 was administered to healthy cynomolgus monkeys (3-30 µmol/kg, p.o.). Plasma levels of MIV-711 and the bone resorption biomarker CTX-I were measured after single dose experiments, and urine levels of CTX-I, NTX-I and CTX-II biomarkers were measured after repeat dose experiments. The safety, pharmacokinetics and pharmacodynamics (serum CTX-I) of MIV-711 were assessed in human healthy subjects after single ascending doses from 20 to 600 mg. MIV-711 was a potent inhibitor of human cathepsin K (K i : 0.98 nmol/L) with > 1300-fold selectivity towards other human cathepsins. MIV-711 inhibited human osteoclast-mediated bone resorption with an IC 50 value of 43 nmol/L. Single oral doses of MIV-711 to monkeys reduced plasma levels of CTX-I in a dose-dependent fashion by up to 57% at trough. The effect on CTX-I was linearly correlated to the plasma exposure of MIV-711, while the efficacy duration outlasted plasma exposure. Repeat oral dosing with MIV-711 also reduced urinary levels of the bone resorption biomarkers CTX-I (by 93%) and NTX-I (by 71%) and the cartilage degradation biomarker CTX-II (by 71%). MIV-711 was safe and well-tolerated when given as single ascending doses to healthy subjects. MIV-711 reduced serum CTX-I levels in a dose-dependent manner by up to 79% at trough. The relationship between MIV-711 exposure and effects on these biomarkers in humans was virtually identical when compared to the corresponding monkey data. MIV-711 is a potent and selective cathepsin K inhibitor with dose-dependent effects on biomarkers of bone and cartilage degradation in monkey and human. Taken together, MIV-711 shows promise for the treatment of bone and cartilage related disorders in humans, such as OA. Trial Registration EudraCT number 2011-003024-12, registered on June 22nd 2011.

Structural Biology and Molecular Modeling in the Design of Novel DPP-4 Inhibitors

NASA Astrophysics Data System (ADS)

Scapin, Giovanna

Inhibition of dipeptidyl peptidase IV (DPP-4) is a promising new approach for the treatment of type 2 diabetes. DPP-4 is the enzyme responsible for inactivating the incretin hormones glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP), two hormones that play important roles in glucose homeostasis. The potent, orally bioavailable and highly selective small molecule DPP-4 inhibitor sitagliptin has been approved by the FDA as novel drug for the treatment of type 2 diabetes. The comparison between the binding mode of sitagliptin (a β-amino acid) and that of a second class of inhibitors (α-amino acid-based) initially led to the successful identification and design of structurally diverse and highly potent DPP-4 inhibitors. Further analysis of the crystal structure of sitagliptin bound to DPP-4 suggested that the central β-amino butanoyl moiety could be replaced by a rigid group. This was confirmed by molecular modeling, and the resulting cyclohexylamine analogs were synthesized and found to be potent DPP-4 inhibitors. However, the triazolopyrazine was predicted to be distorted in order to fit in the binding pocket, and the crystal structure showed that multiple conformations exist for this moiety. Additional molecular modeling studies were then used to improve potency of the cyclohexylamine series. In addition, a 3-D QSAR method was used to gain insight for reducing off-target DPP-8/9 activities. Novel compounds were thus synthesized and found to be potent DPP-4 inhibitors. Two compounds in particular were designed to be highly selective against off-target "DPP-4 Activity- and/or Structure Homologues" (DASH) enzymes while maintaining potency against DPP-4.

Molecular Docking, Pharmacophore, and 3D-QSAR Approach: Can Adenine Derivatives Exhibit Significant Inhibitor Towards Ebola Virus?

PubMed Central

Rai, Amit; Aboumanei, Mohamed H.; Verma, Suraj P.; Kumar, Sachidanand; Raj, Vinit

2017-01-01

Introduction: Ebola Virus Disease (EVD) is caused by Ebola virus, which is often accompanied by fatal hemorrhagic fever upon infection in humans. This virus has caused the majority of deaths in human. There are no proper vaccinations and medications available for EVD. It is pivoting the attraction of scientist to develop the potent vaccination or novel lead to inhibit Ebola virus. Methods & Materials: In the present study, we developed 3D-QSAR and the pharmacophoric model from the previous reported potent compounds for the Ebola virus. Results & Discussion: Results & Discussion: The pharmacophoric model AAAP.116 was generated with better survival value and selectivity. Moreover, the 3D-QSAR model also showed the best r2 value 0.99 using PLS factor. Thereby, we found the higher F value, which demonstrated the statistical significance of both the models. Furthermore, homological modeling and molecular docking study were performed to analyze the affinity of the potent lead. This showed the best binding energy and bond formation with targeted protein. Conclusion: Finally, all the results of this study concluded that 3D-QSAR and Pharmacophore models may be helpful to search potent lead for EVD treatment in future. PMID:29387271

Discovery of highly potent, selective, covalent inhibitors of JAK3

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

Kempson, James; Ovalle, Damaso; Guo, Junqing

A useful and novel set of tool molecules have been identified which bind irreversibly to the JAK3 active site cysteine residue. The design was based on crystal structure information and a comparative study of several electrophilic warheads.

Alleviating CYP and hERG liabilities by structure optimization of dihydrofuran-fused tricyclic benzo[d]imidazole series - Potent, selective and orally efficacious microsomal prostaglandin E synthase-1 (mPGES-1) inhibitors: Part-2.

PubMed

Muthukaman, Nagarajan; Deshmukh, Sanjay; Tambe, Macchindra; Pisal, Dnyandeo; Tondlekar, Shital; Shaikh, Mahamadhanif; Sarode, Neelam; Kattige, Vidya G; Sawant, Pooja; Pisat, Monali; Karande, Vikas; Honnegowda, Srinivasa; Kulkarni, Abhay; Behera, Dayanidhi; Jadhav, Satyawan B; Sangana, Ramchandra R; Gudi, Girish S; Khairatkar-Joshi, Neelima; Gharat, Laxmikant A

2018-04-15

In an effort to identify CYP and hERG clean mPGES-1 inhibitors from the dihydrofuran-fused tricyclic benzo[d]imidazole series lead 7, an extensive structure-activity relationship (SAR) studies were performed. Optimization of A, D and E-rings in 7 afforded many potent compounds with human whole blood potency in the range of 160-950 nM. Selected inhibitors 21d, 21j, 21m, 21n, 21p and 22b provided selectivity against COX-enzymes and mPGES-1 isoforms (mPGES-2 and cPGES) along with sufficient selectivity against prostanoid synthases. Most of the tested analogs demonstrated required metabolic stability in liver microsomes, low hERG and CYP liability. Oral pharmacokinetics and bioavailability of lead compounds 21j, 21m and 21p are discussed in multiple species like rat, guinea pig, dog, and cynomolgus monkey. Besides, these compounds revealed low to moderate activity against human pregnane X receptor (hPXR). The selected lead 21j further demonstrated in vivo efficacy in acute hyperalgesia (ED 50 : 39.6 mg/kg) and MIA-induced osteoarthritic pain models (ED 50 : 106 mg/kg). Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of loxoprofen and its alcohol metabolites for potency and selectivity of inhibition of cyclooxygenase-2.

PubMed

Riendeau, Denis; Salem, Myriam; Styhler, Angela; Ouellet, Marc; Mancini, Joseph A; Li, Chun Sing

2004-03-08

Loxoprofen, its trans-alcohol and cis-alcohol metabolites were evaluated for selectivity of inhibition of COX-2 over COX-1. The (2S,1'R,2'S)-trans-alcohol derivative was found to be the most active metabolite and to be a potent and nonselective inhibitor of COX-2 and COX-1 in both enzyme and human whole blood assays.

Irreversible 4-Aminopiperidine Transglutaminase 2 Inhibitors for Huntington's Disease.

PubMed

Prime, Michael E; Brookfield, Frederick A; Courtney, Stephen M; Gaines, Simon; Marston, Richard W; Ichihara, Osamu; Li, Marie; Vaidya, Darshan; Williams, Helen; Pedret-Dunn, Anna; Reed, Laura; Schaertl, Sabine; Toledo-Sherman, Leticia; Beconi, Maria; Macdonald, Douglas; Muñoz-Sanjuan, Ignacio; Dominguez, Celia; Wityak, John

2012-09-13

A new series of potent TG2 inhibitors are reported that employ a 4-aminopiperidine core bearing an acrylamide warhead. We establish the structure-activity relationship of this new series and report on the transglutaminase selectivity and in vitro ADME properties of selected compounds. We demonstrate that the compounds do not conjugate glutathione in an in vitro setting and have superior plasma stability over our previous series.

Development of small bisquaternary cholinesterase inhibitors as drugs for pre-treatment of nerve agent poisonings

PubMed Central

Kuca, Kamil; Karasova, Jana Zdarova; Soukup, Ondrej; Kassa, Jiri; Novotna, Eva; Sepsova, Vendula; Horova, Anna; Pejchal, Jaroslav; Hrabinova, Martina; Vodakova, Eva; Jun, Daniel; Nepovimova, Eugenie; Valis, Martin; Musilek, Kamil

2018-01-01

Background Intoxication by nerve agents could be prevented by using small acetylcholinesterase inhibitors (eg, pyridostigmine) for potentially exposed personnel. However, the serious side effects of currently used drugs led to research of novel potent molecules for prophylaxis of organophosphorus intoxication. Methods The molecular design, molecular docking, chemical synthesis, in vitro methods (enzyme inhibition, cytotoxicity, and nicotinic receptors modulation), and in vivo methods (acute toxicity and prophylactic effect) were used to study bispyridinium, bisquinolinium, bisisoquinolinium, and pyridinium-quinolinium/isoquinolinium molecules presented in this study. Results The studied molecules showed non-competitive inhibitory ability towards human acetylcholinesterase in vitro that was further confirmed by molecular modelling studies. Several compounds were selected for further studies. First, their cytotoxicity, nicotinic receptors modulation, and acute toxicity (lethal dose for 50% of laboratory animals [LD50]; mice and rats) were tested to evaluate their safety with promising results. Furthermore, their blood levels were measured to select the appropriate time for prophylactic administration. Finally, the protective ratio of selected compounds against soman-induced toxicity was determined when selected compounds were found similarly potent or only slightly better to standard pyridostigmine. Conclusion The presented small bisquaternary molecules did not show overall benefit in prophylaxis of soman-induced in vivo toxicity. PMID:29563775

Fluoroethoxy-1,4-diphenethylpiperidine and piperazine derivatives: Potent and selective inhibitors of [3H]dopamine uptake at the vesicular monoamine transporter-2.

PubMed

Hankosky, Emily R; Joolakanti, Shyam R; Nickell, Justin R; Janganati, Venumadhav; Dwoskin, Linda P; Crooks, Peter A

2017-12-15

A small library of fluoroethoxy-1,4-diphenethyl piperidine and fluoroethoxy-1,4-diphenethyl piperazine derivatives were designed, synthesized and evaluated for their ability to inhibit [ 3 H]dopamine (DA) uptake at the vesicular monoamine transporter-2 (VMAT2) and dopamine transporter (DAT), [ 3 H]serotonin (5-HT) uptake at the serotonin transporter (SERT), and [ 3 H]dofetilide binding at the human-ether-a-go-go-related gene (hERG) channel. The majority of the compounds exhibited potent inhibition of [ 3 H]DA uptake at VMAT2, Ki changes in the nanomolar range (K i  = 0.014-0.073 µM). Compound 15d exhibited the highest affinity (K i  = 0.014 µM) at VMAT2, and had 160-, 5-, and 60-fold greater selectivity for VMAT2 vs. DAT, SERT and hERG, respectively. Compound 15b exhibited the greatest selectivity (>60-fold) for VMAT2 relative to all the other targets evaluated, and 15b had high affinity for VMAT2 (K i  = 0.073 µM). Compound 15b was considered the lead compound from this analog series due to its high affinity and selectivity for VMAT2. Copyright © 2017 Elsevier Ltd. All rights reserved.

1,2,3,4-tetrahydroquinoline-based selective human neuronal nitric oxide synthase (nNOS) inhibitors: lead optimization studies resulting in the identification of N-(1-(2-(methylamino)ethyl)-1,2,3,4-tetrahydroquinolin-6-yl)thiophene-2-carboximidamide as a preclinical development candidate.

PubMed

Ramnauth, Jailall; Renton, Paul; Dove, Peter; Annedi, Subhash C; Speed, Joanne; Silverman, Sarah; Mladenova, Gabriela; Maddaford, Shawn P; Zinghini, Salvatore; Rakhit, Suman; Andrews, John; Lee, David K H; Zhang, Dongqin; Porreca, Frank

2012-03-22

Numerous studies have shown that selective nNOS inhibitors could be therapeutic in many neurological disorders. Previously, we reported a series of 1,2,3,4-tetrahydroquinoline-based potent and selective nNOS inhibitors, highlighted by 1 ( J. Med. Chem. 2011 , 54 , 5562 - 5575 ). Despite showing activity in two rodent pain models, 1 suffered from low oral bioavailability (18%) and moderate hERG channel inhibition (IC(50) = 4.7 μM). To optimize the properties of 1, we synthesized a small focused library containing various alkylamino groups on the 1-position of the 1,2,3,4-tetrahydroquinoline scaffold. The compounds were triaged based on their activity in the NOS and hERG manual patch clamp assays and their calculated physicochemical parameters. From these studies, we identified 47 as a potent and selective nNOS inhibitor with improved oral bioavailability (60%) and no hERG channel inhibition (IC(50) > 30 μM). Furthermore, 47 was efficacious in the Chung model of neuropathic pain and has an excellent safety profile, making it a promising preclinical development candidate.

Simm530, a novel and highly selective c-Met inhibitor, blocks c-Met-stimulated signaling and neoplastic activities

PubMed Central

Peng, Xia; Shen, Yanyan; Chen, Fang; Ji, Yinchun; Liu, Weiren; Shi, Yinghong; Duan, Wenhu; Ding, Jian; Ai, Jing; Geng, Meiyu

2016-01-01

The aberrant c-Met activation has been implicated in a variety of human cancers for its critical role in tumor growth, metastasis and tumor angiogenesis. Thus, c-Met axis presents as an attractive therapeutic target. Notably, most of these c-Met inhibitors currently being evaluated in clinical trials lack selectivity and target multiple kinases, often accounting for the undesirable toxicities. Here we described Simm530 as a potent and selective c-Met inhibitor. Simm530 demonstrated >2,000 fold selectivity for c-Met compared with other 282 kinases, making it one of the most selective c-Met inhibitors described to date. This inhibitor significantly blocked c-Met signaling pathways regardless of mechanistic complexity implicated in c-Met activation. As a result, Simm530 led to substantial inhibition of c-Met-promoted cell proliferation, migration, invasion, ECM degradation, cell scattering and invasive growth. In addition, Simm530 inhibited primary human umbilical vascular endothelial cell (HUVEC) proliferation, decreased intratumoral CD31 expression and plasma pro-angiogenic factor interleukin-8 secretion, suggesting its significant anti-angiogenic properties. Simm530 resulted in dose-dependent inhibition of c-Met phosphorylation and tumor growth in c-Met-driven lung and gastric cancer xenografts. And, the inhibitor is well tolerated even at doses that achieve complete tumor regression. Together, Simm530 is a potent and highly selective c-Met kinase inhibitor that may have promising therapeutic potential in c-Met-driven cancer treatment. PMID:27191264

Design of Potent and Selective Inhibitors to Overcome Clinical Anaplastic Lymphoma Kinase Mutations Resistant to Crizotinib

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

Huang, Qinhua; Johnson, Ted W.; Bailey, Simon

2014-02-27

Crizotinib (1), an anaplastic lymphoma kinase (ALK) receptor tyrosine kinase inhibitor approved by the U.S. Food and Drug Administration in 2011, is efficacious in ALK and ROS positive patients. Under pressure of crizotinib treatment, point mutations arise in the kinase domain of ALK, resulting in resistance and progressive disease. The successful application of both structure-based and lipophilic-efficiency-focused drug design resulted in aminopyridine 8e, which was potent across a broad panel of engineered ALK mutant cell lines and showed suitable preclinical pharmacokinetics and robust tumor growth inhibition in a crizotinib-resistant cell line (H3122-L1196M).

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

SAR and X-ray Structures of Enantiopure 1,2-cis-(1R,2S)-cyclopentyldiamine and Cyclohexyldiamine Derivativies as Inhibitors of Coagulation Factor Xa

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

Qiao,J.; Chang, C.; Cheney, D.

In the search of Factor Xa (FXa) inhibitors structurally different from the pyrazole-based series, we identified a viable series of enantiopure cis-(1R,2S)-cycloalkyldiamine derivatives as potent and selective inhibitors of FXa. Among them, cyclohexyldiamide 7 and cyclopentyldiamide 9 were the most potent neutral compounds, and had good anticoagulant activity comparable to the pyrazole-based analogs. Crystal structures of 7-FXa and 9-FXa illustrate binding similarities and differences between the five- and the six-membered core systems, and provide rationales for the observed SAR of P1 and linker moieties.

Minor Structural Change to Tertiary Sulfonamide RORc Ligands Led to Opposite Mechanisms of Action

PubMed Central

2014-01-01

A minor structural change to tertiary sulfonamide RORc ligands led to distinct mechanisms of action. Co-crystal structures of two compounds revealed mechanistically consistent protein conformational changes. Optimized phenylsulfonamides were identified as RORc agonists while benzylsulfonamides exhibited potent inverse agonist activity. Compounds behaving as agonists in our biochemical assay also gave rise to an increased production of IL-17 in human PBMCs whereas inverse agonists led to significant suppression of IL-17 under the same assay conditions. The most potent inverse agonist compound showed >180-fold selectivity over the ROR isoforms as well as all other nuclear receptors that were profiled. PMID:25815138

Synthesis, absolute configuration and antimuscarinic activity of the enantiomers of [1-(2,2-diphenyl-[1,3]dioxolan-4-yl)-ethyl]-dimethyl-amine.

PubMed

Gulini, U; Angeli, P; Marucci, G; Buccioni, M; Giardinà, D; Antolini, L; Franchini, S; Sorbi, C; Brasili, L

2001-01-22

Methylation of the carbon atom C of compound 1, a potent and not selective muscarinic antagonist, was carried out. The resulting diastereomers were separated and the corresponding racemate further resolved to give four enantiomers, which were tested both as hydrogen oxalate and methiodide salts. The pharmacological results obtained at M1, M2 and M3 muscarinic receptor subtypes, show that methylation at C1, depending on the stereochemistry, increases antagonist potency, having thus the same effect of nitrogen quaternization. These results may well lead to the development of new potent antimuscarinic drugs lacking a cationic head.

Seasonal Variation of the Effect of Extremely Diluted Agitated Gibberellic Acid (10e-30) on Wheat Stalk Growth: A Multiresearcher Study

PubMed Central

Endler, Peter Christian; Matzer, Wolfgang; Reich, Christian; Reischl, Thomas; Hartmann, Anna Maria; Thieves, Karin; Pfleger, Andrea; Hofäcker, Jürgen; Lothaller, Harald; Scherer-Pongratz, Waltraud

2011-01-01

The influence of a homeopathic high dilution of gibberellic acid on wheat growth was studied at different seasons of the year. Seedlings were allowed to develop under standardized conditions for 7 days; plants were harvested and stalk lengths were measured. The data obtained confirm previous findings, that ultrahigh diluted potentized gibberellic acid affects stalk growth. Furthermore, the outcome of the study suggests that experiments utilizing the bioassay presented should best be performed in autumn season. In winter and spring, respectively, no reliable effects were found. PMID:22125426

Progressive outer retinal necrosis after rituximab and cyclophosphamide therapy.

PubMed

Dogra, Mohit; Bajgai, Priya; Kumar, Ashok; Sharma, Aman

2018-04-01

We report a case of progressive outer retinal necrosis (PORN) in a patient of microscopic polyangitis (MPA), being treated with immunosuppressive drugs such as cyclophosphamide and rituximab. Her aqueous tap was positive for Varicella Zoster virus and she was treated with oral and intravitreal antivirals, along with discontinuation of one of the immunosuppressive agents, i.e. rituximab, which might have led to reactivation of the virus causing necrotizing retinitis lesions. Rituximab and cyclophosphamide are extremely potent drugs, which are necessary to manage immunological disorders such as MPA. However, they may predispose the patient to serious complications like viral infections, including PORN.

Clostridium botulinum and the ophthalmologist: a review of botulism, including biological warfare ramifications of botulinum toxin.

PubMed

Caya, J G

2001-01-01

The anaerobic bacterium Clostridium botulinum causes disease by elaborating an extremely potent neurotoxin that inhibits release of acetylcholine at presynaptic nerve endings, thereby resulting in a descending flaccid paralysis and autonomic nervous system dysfunction. Possible ophthalmological effects of this neurotoxin are many and typically constitute the earliest manifestations of botulism. This review summarizes the medical literature on botulism with regard to historical perspective, epidemiology, clinical manifestations, and treatment. Ophthalmological findings of botulism are tabulated and their frequencies are provided. Finally, the bioterrorism/biologic warfare ramifications of botulinum toxin are briefly discussed.

Researchers unmask secret to long-lasting effects of botulinum neurotoxin A in motor neurons | Center for Cancer Research

Cancer.gov

A team of scientists led by the Center for Cancer Research's Allan M. Weissman, M.D., and Yien Che Tsai, Ph.D., has discovered a molecular mechanism that explains the extreme toxicity of botulinum neurotoxin A (BoNT/A), the most potent BoNT strain. The discovery, published June 5 in PNAS, also identifies a molecular target that the researchers hope will eventually lead to improved therapies to treat exposure and severely undermine the potential use of BoNTs as bioweapons.  Read more...  

Medical Imaging of Neglected Tropical Diseases of the Americas.

PubMed

Jones, Patrick; Mazal, Jonathan

2016-01-01

Neglected tropical diseases are a group of protozoan, parasitic, bacterial, and viral diseases endemic in 149 countries causing substantial illness globally. Extreme poverty and warm tropical climates are the 2 most potent forces promoting the spread of neglected tropical diseases. These forces are prevalent in Central and South America, as well as the U.S. Gulf Coast. Advanced cases often require specialized medical imaging for diagnosis, disease staging, and follow-up. This article offers a review of epidemiology, pathophysiology, clinical manifestations, diagnosis (with special attention to medical imaging), and treatment of neglected tropical diseases specific to the Americas.

Statistic analysis of annual total ozone extremes for the period 1964-1988

NASA Technical Reports Server (NTRS)

Krzyscin, Janusz W.

1994-01-01

Annual extremes of total column amount of ozone (in the period 1964-1988) from a network of 29 Dobson stations have been examined using the extreme value analysis. The extremes have been calculated as the highest deviation of daily mean total ozone from its long-term monthly mean, normalized by the monthly standard deviations. The extremes have been selected from the direct-Sun total ozone observations only. The extremes resulting from abrupt changes in ozone (day to day changes greater than 20 percent) have not been considered. The ordered extremes (maxima in ascending way, minima in descending way) have been fitted to one of three forms of the Fisher-Tippet extreme value distribution by the nonlinear least square method (Levenberg-Marguard method). We have found that the ordered extremes from a majority of Dobson stations lie close to Fisher-Tippet type III. The extreme value analysis of the composite annual extremes (combined from averages of the annual extremes selected at individual stations) has shown that the composite maxima are fitted by the Fisher-Tippet type III and the composite minima by the Fisher-Tippet type I. The difference between the Fisher-Tippet types of the composite extremes seems to be related to the ozone downward trend. Extreme value prognoses for the period 1964-2014 (derived from the data taken at: all analyzed stations, the North American, and the European stations) have revealed that the prognostic extremes are close to the largest annual extremes in the period 1964-1988 and there are only small regional differences in the prognoses.

Modeling extreme PM10 concentration in Malaysia using generalized extreme value distribution

NASA Astrophysics Data System (ADS)

Hasan, Husna; Mansor, Nadiah; Salleh, Nur Hanim Mohd

2015-05-01

Extreme PM10 concentration from the Air Pollutant Index (API) at thirteen monitoring stations in Malaysia is modeled using the Generalized Extreme Value (GEV) distribution. The data is blocked into monthly selection period. The Mann-Kendall (MK) test suggests a non-stationary model so two models are considered for the stations with trend. The likelihood ratio test is used to determine the best fitted model and the result shows that only two stations favor the non-stationary model (Model 2) while the other eleven stations favor stationary model (Model 1). The return level of PM10 concentration that is expected to exceed the maximum once within a selected period is obtained.

Discovery and synthesis of a novel and selective drug-like P2X(1) antagonist.

PubMed

Jaime-Figueroa, S; Greenhouse, R; Padilla, F; Dillon, M P; Gever, J R; Ford, A P D W

2005-07-01

Although there is extensive literature to indicate that many different types of P2 purinoceptors are present in the lower urinary tract, the physiological role of these receptors in micturition is still uncertain. In part, this uncertainty has been caused by a lack of P2 subtype selective ligands. In this paper we report the discovery, gram scale synthesis, and binding results for 1, the first potent, drug-like, selective P2X(1) receptor antagonist described. Compound 1 was shown to be more than 30-fold selective over other purinergic receptor subtypes.

A combinatorial feature selection approach to describe the QSAR of dual site inhibitors of acetylcholinesterase.

PubMed

Asadabadi, Ebrahim Barzegari; Abdolmaleki, Parviz; Barkooie, Seyyed Mohsen Hosseini; Jahandideh, Samad; Rezaei, Mohammad Ali

2009-12-01

Regarding the great potential of dual binding site inhibitors of acetylcholinesterase as the future potent drugs of Alzheimer's disease, this study was devoted to extraction of the most effective structural features of these inhibitors from among a large number of quantitative descriptors. To do this, we adopted a unique approach in quantitative structure-activity relationships. An efficient feature selection method was emphasized in such an approach, using the confirmative results of different routine and novel feature selection methods. The proposed methods generated quite consistent results ensuring the effectiveness of the selected structural features.

Lead selection and characterization of antitubercular compounds using the Nested Chemical Library.

PubMed

Sipos, Anna; Pató, János; Székely, Rita; Hartkoorn, Ruben C; Kékesi, László; Őrfi, László; Szántai-Kis, Csaba; Mikušová, Katarína; Svetlíková, Zuzana; Korduláková, Jana; Nagaraja, Valakunja; Godbole, Adwait Anand; Bush, Natassja; Collin, Frédéric; Maxwell, Anthony; Cole, Stewart T; Kéri, György

2015-06-01

Discovering new drugs to treat tuberculosis more efficiently and to overcome multidrug resistance is a world health priority. To find novel antitubercular agents several approaches have been used in various institutions worldwide, including target-based approaches against several validated mycobacterial enzymes and phenotypic screens. We screened more than 17,000 compounds from Vichem's Nested Chemical Library™ using an integrated strategy involving whole cell-based assays with Corynebacterium glutamicum and Mycobacterium tuberculosis, and target-based assays with protein kinases PknA, PknB and PknG as well as other targets such as PimA and bacterial topoisomerases simultaneously. With the help of the target-based approach we have found very potent hits inhibiting the selected target enzymes, but good minimal inhibitory concentrations (MIC) against M. tuberculosis were not achieved. Focussing on the whole cell-based approach several potent hits were found which displayed minimal inhibitory concentrations (MIC) against M. tuberculosis below 10 μM and were non-mutagenic, non-cytotoxic and the targets of some of the hits were also identified. The most active hits represented various scaffolds. Medicinal chemistry-based lead optimization was performed applying various strategies and, as a consequence, a series of novel potent compounds were synthesized. These efforts resulted in some effective potential antitubercular lead compounds which were confirmed in phenotypic assays. Copyright © 2015 Elsevier Ltd. All rights reserved.

Kinetics and docking studies of a COX-2 inhibitor isolated from Terminalia bellerica fruits.

PubMed

Reddy, Tamatam Chandramohan; Aparoy, Polamarasetty; Babu, Neela Kishore; Kumar, Kotha Anil; Kalangi, Suresh Kumar; Reddanna, Pallu

2010-10-01

Triphala is an Ayurvedic herbal formulation consisting of equal parts of three myrobalans: Terminalia chebula, Terminalia bellerica and Emblica officinalis. We recently reported that chebulagic acid (CA) isolated from Terminalia chebula is a potent COX-2/5-LOX dual inhibitor. In this study, compounds isolated from Terminalia bellerica were tested for inhibition against COX and 5-LOX. One of the fractionated compounds showed potent inhibition against COX enzymes with no inhibition against 5-LOX. It was identified as gallic acid (GA) by LC-MS, NMR and IR analyses. We report here the inhibitory effects of GA, with an IC(50) value of 74 nM against COX-2 and 1500 nM for COX-1, showing ≈20 fold preference towards COX-2. Further docking studies revealed that GA binds in the active site of COX-2 at the non-steroidal anti-inflammatory drug (NSAID) binding site. The carboxylate moiety of GA interacts with Arg120 and Glu524. Based on substrate dependent kinetics, GA was found to be a competitive inhibitor of both COX-1 and COX-2, with more affinity towards COX-2. Taken together, our studies indicate that GA is a selective inhibitor of COX-2. Being a small natural product with selective and reversible inhibition of COX-2, GA would form a lead molecule for developing potent anti-inflammatory drug candidates.

Combinatorial RNA Interference Therapy Prevents Selection of Pre-existing HBV Variants in Human Liver Chimeric Mice

PubMed Central

Shih, Yao-Ming; Sun, Cheng-Pu; Chou, Hui-Hsien; Wu, Tzu-Hui; Chen, Chun-Chi; Wu, Ping-Yi; Enya Chen, Yu-Chen; Bissig, Karl-Dimiter; Tao, Mi-Hua

2015-01-01

Selection of escape mutants with mutations within the target sequence could abolish the antiviral RNA interference activity. Here, we investigated the impact of a pre-existing shRNA-resistant HBV variant on the efficacy of shRNA therapy. We previously identified a highly potent shRNA, S1, which, when delivered by an adeno-associated viral vector, effectively inhibits HBV replication in HBV transgenic mice. We applied the “PICKY” software to systemically screen the HBV genome, then used hydrodynamic transfection and HBV transgenic mice to identify additional six highly potent shRNAs. Human liver chimeric mice were infected with a mixture of wild-type and T472C HBV, a S1-resistant HBV variant, and then treated with a single or combined shRNAs. The presence of T472C mutant compromised the therapeutic efficacy of S1 and resulted in replacement of serum wild-type HBV by T472C HBV. In contrast, combinatorial therapy using S1 and P28, one of six potent shRNAs, markedly reduced titers for both wild-type and T472C HBV. Interestingly, treatment with P28 alone led to the emergence of escape mutants with mutations in the P28 target region. Our results demonstrate that combinatorial RNAi therapy can minimize the escape of resistant viral mutants in chronic HBV patients. PMID:26482836

De Novo Design and Synthesis of Ultra-Short Peptidomimetic Antibiotics Having Dual Antimicrobial and Anti-Inflammatory Activities

PubMed Central

Ahn, Mija; Hwang, Eunha; Sohn, Hoik; Park, Hyo-Nam; Lee, Eunjung; Seo, Ji-Hyung; Cheong, Chaejoon; Nam, Ky-Youb; Hyun, Jae-Kyung; Jeong, Ki-Woong; Kim, Yangmee; Shin, Song Yub; Bang, Jeong Kyu

2013-01-01

Background Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability. Methodology/Principal Findings In an attempt to overcome the issues described above, a set of ultra-short, His-derived antimicrobial peptides (HDAMPs) has been developed for the first time. Through systematic tuning of pendant hydrophobic alkyl tails at the N(π)- and N(τ)-positions on His, and the positive charge of Arg, much higher prokaryotic selectivity was achieved, compared to human AMP LL-37. Additionally, the most potent HDAMPs showed promising dual antimicrobial and anti-inflammatory activities, as well as anti–methicillin-resistant Staphylococcus aureus (MRSA) activity and proteolytic resistance. Our results from transmission electron microscopy, membrane depolarization, confocal laser-scanning microscopy, and calcein-dye leakage experiments propose that HDAMP-1 kills microbial cells via dissipation of the membrane potential by forming pore/ion channels on bacterial cell membranes. Conclusion/Significance The combination of the ultra-short size, high-prokaryotic selectivity, potent anti-MRSA activity, anti-inflammatory activity, and proteolytic resistance of the designed HDAMP-1, -3, -5, and -6 makes these molecules promising candidates for future antimicrobial therapeutics. PMID:24302996

FV-100: the most potent and selective anti-varicella zoster virus agent reported to date.

PubMed

Migliore, Marco

2010-01-05

Bicyclic aryl furano pyrimidines represent the most potent anti-varicella zoster virus (VZV) agents reported to date. Lead compounds have 50% effective concentration (EC(50)) values in vitro that are in the subnanomolar range and selectivity index values that exceed 1 million. They have an absolute requirement for VZV thymidine kinase and most likely act as their phosphate forms. Some structural modification (such as aryl substitution in the base moiety) is tolerated, whereas little sugar modification is acceptable. The Cf1743 compound has proved to be significantly more potent than all reference anti-VZV compounds, as measured either by inhibition of infectious virus particles and/or viral DNA production; however, the high lipophilicity and very low water solubility of this compound gives poor oral bioavailability (<14%). Use of the modified cyclodextrin captisol and the synthesis of the 5'-monophosphate prodrug of Cf1743 has significantly improved water solubility, but does not give any enhancement in oral bioavailability. By contrast, the synthesis of the ether series does not give any further improvement in terms of solubility. The most promising prodrug to emerge to date is the hydrochloric salt of the 5'-valyl-ester, designated as FV-100. Its uptake into cells has been studied using fluorescent microscopy and biological assays, which have indicated that the compound is efficiently taken up by the cells after a short period of incubation.

Single vector platform vaccine protects against lethal respiratory challenge with Tier 1 select agents of anthrax, plague, and tularemia.

PubMed

Jia, Qingmei; Bowen, Richard; Dillon, Barbara Jane; Masleša-Galić, Saša; Chang, Brennan T; Kaidi, Austin C; Horwitz, Marcus A

2018-05-03

Bacillus anthracis, Yersinia pestis, and Francisella tularensis are the causative agents of Tier 1 Select Agents anthrax, plague, and tularemia, respectively. Currently, there are no licensed vaccines against plague and tularemia and the licensed anthrax vaccine is suboptimal. Here we report F. tularensis LVS ΔcapB (Live Vaccine Strain with a deletion in capB)- and attenuated multi-deletional Listeria monocytogenes (Lm)-vectored vaccines against all three aforementioned pathogens. We show that LVS ΔcapB- and Lm-vectored vaccines express recombinant B. anthracis, Y. pestis, and F. tularensis immunoprotective antigens in broth and in macrophage-like cells and are non-toxic in mice. Homologous priming-boosting with the LVS ΔcapB-vectored vaccines induces potent antigen-specific humoral and T-cell-mediated immune responses and potent protective immunity against lethal respiratory challenge with all three pathogens. Protection against anthrax was far superior to that obtained with the licensed AVA vaccine and protection against tularemia was comparable to or greater than that obtained with the toxic and unlicensed LVS vaccine. Heterologous priming-boosting with LVS ΔcapB- and Lm-vectored B. anthracis and Y. pestis vaccines also induced potent protective immunity against lethal respiratory challenge with B. anthracis and Y. pestis. The single vaccine platform, especially the LVS ΔcapB-vectored vaccine platform, can be extended readily to other pathogens.

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

Design, synthesis, pharmacological evaluation, QSAR analysis, molecular modeling and ADMET of novel donepezil-indolyl hybrids as multipotent cholinesterase/monoamine oxidase inhibitors for the potential treatment of Alzheimer's disease.

PubMed

Bautista-Aguilera, Oscar M; Esteban, Gerard; Bolea, Irene; Nikolic, Katarina; Agbaba, Danica; Moraleda, Ignacio; Iriepa, Isabel; Samadi, Abdelouahid; Soriano, Elena; Unzeta, Mercedes; Marco-Contelles, José

2014-03-21

The design, synthesis, and pharmacological evaluation of donepezil-indolyl based amines 7-10, amides 12-16, and carboxylic acid derivatives 5 and 11, as multipotent ASS234 analogs, able to inhibit simultaneously cholinesterase (ChE) and monoamine oxidase (MAO) enzymes for the potential treatment of Alzheimer's disease (AD), is reported. Theoretical studies using 3D-Quantitative Structure-Activity Relationship (3D-QSAR) was used to define 3D-pharmacophores for inhibition of MAO A/B, AChE, and BuChE enzymes. We found that, in general, and for the same substituent, amines are more potent ChE inhibitors (see compounds 12, 13 versus 7 and 8) or equipotent (see compounds 14, 15 versus 9 and 10) than the corresponding amides, showing a clear EeAChE inhibition selectivity. For the MAO inhibition, amides were not active, and among the amines, compound 14 was totally MAO A selective, while amines 15 and 16 were quite MAO A selective. Carboxylic acid derivatives 5 and 11 showed a multipotent moderate selective profile as EeACE and MAO A inhibitors. Propargylamine 15 [N-((5-(3-(1-benzylpiperidin-4-yl)propoxy)-1-methyl-1H-indol-2-yl)methyl)prop-2-yn-1-amine] resulted in the most potent hMAO A (IC50 = 5.5 ± 1.4 nM) and moderately potent hMAO B (IC50 = 150 ± 31 nM), EeAChE (IC50 = 190 ± 10 nM), and eqBuChE (IC50 = 830 ± 160 nM) inhibitor. However, the analogous N-allyl and the N-morpholine derivatives 16 and 14 deserve also attention as they show an attractive multipotent profile. To sum up, donepezil-indolyl hybrid 15 is a promising drug for further development for the potential prevention and treatment of AD. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Assessing the role of metabotropic glutamate receptor 5 in multiple nociceptive modalities.

PubMed

Zhu, Chang Z; Wilson, Sonya G; Mikusa, Joseph P; Wismer, Carol T; Gauvin, Donna M; Lynch, James J; Wade, Carrie L; Decker, Michael W; Honore, Prisca

2004-12-15

Preclinical data, performed in a limited number of pain models, suggest that functional blockade of metabotropic glutamate (mGlu) receptors may be beneficial for pain management. In the present study, effects of 2-methyl-6-(phenylethynyl)-pyridine (MPEP), a potent, selective mGlu5 receptor antagonist, were examined in a wide variety of rodent nociceptive and hypersensitivity models in order to fully characterize the potential analgesic profile of mGlu5 receptor blockade. Effects of 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP), as potent and selective as MPEP at mGlu5/mGlu1 receptors but more selective than MPEP at N-methyl-aspartate (NMDA) receptors, were also evaluated in selected nociceptive and side effect models. MPEP (3-30 mg/kg, i.p.) produced a dose-dependent reversal of thermal and mechanical hyperalgesia following complete Freund's adjuvant (CFA)-induced inflammatory hypersensitivity. Additionally, MPEP (3-30 mg/kg, i.p.) decreased thermal hyperalgesia observed in carrageenan-induced inflammatory hypersensitivity without affecting paw edema, abolished acetic acid-induced writhing activity in mice, and was shown to reduce mechanical allodynia and thermal hyperalgesia observed in a model of post-operative hypersensitivity and formalin-induced spontaneous pain. Furthermore, at 30 mg/kg, i.p., MPEP significantly attenuated mechanical allodynia observed in three neuropathic pain models, i.e. spinal nerve ligation, sciatic nerve constriction and vincristine-induced neuropathic pain. MTEP (3-30 mg/kg, i.p.) also potently reduced CFA-induced thermal hyperalgesia. However, at 100 mg/kg, i.p., MPEP and MTEP produced central nerve system (CNS) side effects as measured by rotarod performance and exploratory locomotor activity. These results suggest a role for mGlu5 receptors in multiple nociceptive modalities, though CNS side effects may be a limiting factor in developing mGlu5 receptor analgesic compounds.

Histamine H{sub 3} receptor antagonist OUP-186 attenuates the proliferation of cultured human breast cancer cell lines

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

Tanaka, Satoshi; Sakaguchi, Minoru; Yoneyama, Hiroki

Histamine is involved in various physiological functions, including its neurotransmitter actions in the central nervous system and its action as a causative agent of inflammation, allergic reactions, and gastric acid secretions. Histamine expression and biosynthesis have been detected in breast cancer cells. It was recently suggested that the histamine H{sub 3} receptor (H{sub 3}R) plays a role in the proliferation of breast cancer cells. We recently developed the non-imidazole H{sub 3}R antagonist OUP-186 which exhibited a potent and selective human H{sub 3}R antagonistic activity as well as no activity against the human histamine H{sub 4} receptor (H{sub 4}R). In thismore » study, we compared the effects of OUP-186 on the proliferation of estrogen receptor negative (ER−) breast cancer cells (MDA-MB-231) and ER+ breast cancer cells (MCF7) to the effects of clobenpropit (potent imidazole-containing H{sub 3}R antagonist). OUP-186 and clobenpropit suppressed the proliferation of breast cancer cells. The IC{sub 50} values at 48 h for OUP-186 and clobenpropit were approximately 10 μM and 50 μM, respectively. Furthermore, OUP-186 potently induced cell death by activating caspase-3/7, whereas cell death was only slightly induced by clobenpropit. In addition, OUP-186 treatment blocked the proliferation increase triggered by 100 μM (R)-(-)-α-methylhistamine (H{sub 3}R agonist). The use of 4-methylhistamine (H{sub 4}R agonist) and JNJ10191584 (selective H{sub 4}R antagonist) did not affect breast cancer proliferation. These results indicate that OUP-186 potently suppresses proliferation and induces caspase-dependent apoptotic death in both ER+ and ER-breast cancer cells. - Highlights: • OUP-186, a histamine H{sub 3} receptor antagonist, effects breast cancer cell growth. • OUP-186 potently suppressed proliferation and induced caspase-dependent apoptosis. • OUP-186 may be an effective drug against ER+ and ER− breast cancers.« less

Inhibitors of cyclin-dependent kinases as cancer therapeutics.

PubMed

Whittaker, Steven R; Mallinger, Aurélie; Workman, Paul; Clarke, Paul A

2017-05-01

Over the past two decades there has been a great deal of interest in the development of inhibitors of the cyclin-dependent kinases (CDKs). This attention initially stemmed from observations that different CDK isoforms have key roles in cancer cell proliferation through loss of regulation of the cell cycle, a hallmark feature of cancer. CDKs have now been shown to regulate other processes, particularly various aspects of transcription. The early non-selective CDK inhibitors exhibited considerable toxicity and proved to be insufficiently active in most cancers. The lack of patient selection biomarkers and an absence of understanding of the inhibitory profile required for efficacy hampered the development of these inhibitors. However, the advent of potent isoform-selective inhibitors with accompanying biomarkers has re-ignited interest. Palbociclib, a selective CDK4/6 inhibitor, is now approved for the treatment of ER+/HER2- advanced breast cancer. Current developments in the field include the identification of potent and selective inhibitors of the transcriptional CDKs; these include tool compounds that have allowed exploration of individual CDKs as cancer targets and the determination of their potential therapeutic windows. Biomarkers that allow the selection of patients likely to respond are now being discovered. Drug resistance has emerged as a major hurdle in the clinic for most protein kinase inhibitors and resistance mechanism are beginning to be identified for CDK inhibitors. This suggests that the selective inhibitors may be best used combined with standard of care or other molecularly targeted agents now in development rather than in isolation as monotherapies. Copyright © 2017 Elsevier Inc. All rights reserved.

ONC201 selectively induces apoptosis in cutaneous T-cell lymphoma cells via activating pro-apoptotic integrated stress response and inactivating JAK/STAT and NF-κB pathways

PubMed Central

Ni, Xiao; Zhang, Xiang; Hu, Cheng-Hui; Langridge, Timothy; Tarapore, Rohinton S.; Allen, Joshua E.; Oster, Wolfgang; Duvic, Madeleine

2017-01-01

Cutaneous T-cell lymphomas (CTCLs) are extremely symptomatic and still incurable, and more effective and less toxic therapies are urgently needed. ONC201, an imipridone compound, has shown efficacy in pre-clinical studies in multiple advanced cancers. This study was to evaluate the anti-tumor activity of ONC201 on CTCL cells. The effect of ONC201 on the cell growth and apoptosis were evaluated in CTCL cell lines (n=8) and primary CD4+ malignant T cells isolated from CTCL patients (n=5). ONC201 showed a time-dependent cell growth inhibition in all treated cell lines with a concentration range of 1.25-10.0 μM. ONC201 also induced apoptosis in tested cells with a narrow concentration range of 2.5-10.0 μM, evidenced by increased Annexin V+ cells, accompanied by accumulated sub-G1 portions. ONC201 only induced apoptosis in CD4+ malignant T cells, not in normal CD4+ T cells. The activating transcription factor 4 (ATF4), a hallmark of integrated stress response, was upregulated in response to ONC201 whereas Akt was downregulated. In addition, molecules in JAK/STAT and NF-κB pathways, as well as IL-32β, were downregulated following ONC201 treatment. Thus, ONC201 exerts a potent and selective anti-tumor effect on CTCL cells. Its efficacy may involve activating integrated stress response through ATF4 and inactivating JAK/STAT and NF-κB pathways. PMID:28977902

ONC201 selectively induces apoptosis in cutaneous T-cell lymphoma cells via activating pro-apoptotic integrated stress response and inactivating JAK/STAT and NF-κB pathways.

PubMed

Ni, Xiao; Zhang, Xiang; Hu, Cheng-Hui; Langridge, Timothy; Tarapore, Rohinton S; Allen, Joshua E; Oster, Wolfgang; Duvic, Madeleine

2017-09-22

Cutaneous T-cell lymphomas (CTCLs) are extremely symptomatic and still incurable, and more effective and less toxic therapies are urgently needed. ONC201, an imipridone compound, has shown efficacy in pre-clinical studies in multiple advanced cancers. This study was to evaluate the anti-tumor activity of ONC201 on CTCL cells. The effect of ONC201 on the cell growth and apoptosis were evaluated in CTCL cell lines (n=8) and primary CD4 + malignant T cells isolated from CTCL patients (n=5). ONC201 showed a time-dependent cell growth inhibition in all treated cell lines with a concentration range of 1.25-10.0 μM. ONC201 also induced apoptosis in tested cells with a narrow concentration range of 2.5-10.0 μM, evidenced by increased Annexin V + cells, accompanied by accumulated sub-G1 portions. ONC201 only induced apoptosis in CD4 + malignant T cells, not in normal CD4 + T cells. The activating transcription factor 4 (ATF4), a hallmark of integrated stress response, was upregulated in response to ONC201 whereas Akt was downregulated. In addition, molecules in JAK/STAT and NF-κB pathways, as well as IL-32β, were downregulated following ONC201 treatment. Thus, ONC201 exerts a potent and selective anti-tumor effect on CTCL cells. Its efficacy may involve activating integrated stress response through ATF4 and inactivating JAK/STAT and NF-κB pathways.

Discovery of a potent nanoparticle P-selectin antagonist with anti-inflammatory effects in allergic airway disease

PubMed Central

John, Alison E.; Lukacs, Nicholas W.; Berlin, Aaron A.; Palecanda, Aiyappa; Bargatze, Robert F.; Stoolman, Lloyd M.; Nagy, Jon O.

2010-01-01

The severity of allergic asthma is dependent, in part, on the intensity of peribronchial inflammation. P-selectin is known to play a role in the development of allergen-induced peribronchial inflammation and airway hyperreactivity. Selective inhibitors of P-selectin-mediated leukocyte endothelial-cell interactions may therefore attenuate the inflammatory processes associated with allergic airway disease. Novel P-selectin inhibitors were created using a polyvalent polymer nanoparticle capable of displaying multiple synthetic, low molecular weight ligands. By assembling a particle that presents an array of groups, which as monomers interact with only low affinity, we created a construct that binds extremely efficiently to P-selectin. The ligands acted as mimetics of the key binding elements responsible for the high-avidity adhesion of P-selectin to the physiologic ligand, PSGL-1. The inhibitors were initially evaluated using an in vitro shear assay system in which interactions between circulating cells and P-selectin-coated capillary tubes were measured. The nanoparticles were shown to preferentially bind to selectins expressed on activated endothelial cells. We subsequently demonstrated that nanoparticles displaying P-selectin blocking arrays were functionally active in vivo, significantly reducing allergen-induced airway hyperreactivity and peribronchial eosinophilic inflammation in a murine model of asthma. PMID:14563683

Superior analgesic effect of H-Dmt-D-Arg-Phe-Lys-NH2 ([Dmt1]DALDA), a multifunctional opioid peptide, compared to morphine in a rat model of neuropathic pain.

PubMed

Shimoyama, Megumi; Schiller, Peter W; Shimoyama, Naohito; Toyama, Satoshi; Szeto, Hazel H

2012-11-01

H-Dmt-D-Arg-Phe-Lys-NH(2) ([Dmt(1)]DALDA) is a synthetic tetrapeptide with extraordinary selectivity for the mu-opioid receptor and is an extremely potent analgesic. [Dmt(1) ]DALDA is unusual in the way that the greater part of its analgesic potency appears to be produced by its actions in the spinal cord. Furthermore, [Dmt(1) ]DALDA inhibits norepinephrine re-uptake and is a mitochondria-targeted antioxidant. Such characteristics may make [Dmt(1)]DALDA particularly effective against neuropathic pain. The present study was designed to compare the effects of [Dmt(1)]DALDA and morphine on thermal hyperalgesia in an experimental neuropathic pain model. Neuropathic pain was induced in rats by surgical ligation of the L5 spinal nerve, and thermal pain thresholds were assessed by latencies of paw withdrawal to radiant heat. The increase in paw withdrawal latency was greater after the administration of [Dmt(1) ]DALDA than that of morphine in neuropathic rats at doses that were equianalgesic in naïve animals. We conclude that [Dmt(1)]DALDA is more effective than morphine against thermal hyperalgesia in this experimental model of neuropathic pain. © 2012 John Wiley & Sons A/S.

Pharmacological reversal of a pain phenotype in iPSC-derived sensory neurons and patients with inherited erythromelalgia.

PubMed

Cao, Lishuang; McDonnell, Aoibhinn; Nitzsche, Anja; Alexandrou, Aristos; Saintot, Pierre-Philippe; Loucif, Alexandre J C; Brown, Adam R; Young, Gareth; Mis, Malgorzata; Randall, Andrew; Waxman, Stephen G; Stanley, Philip; Kirby, Simon; Tarabar, Sanela; Gutteridge, Alex; Butt, Richard; McKernan, Ruth M; Whiting, Paul; Ali, Zahid; Bilsland, James; Stevens, Edward B

2016-04-20

In common with other chronic pain conditions, there is an unmet clinical need in the treatment of inherited erythromelalgia (IEM). TheSCN9Agene encoding the sodium channel Nav1.7 expressed in the peripheral nervous system plays a critical role in IEM. A gain-of-function mutation in this sodium channel leads to aberrant sensory neuronal activity and extreme pain, particularly in response to heat. Five patients with IEM were treated with a new potent and selective compound that blocked the Nav1.7 sodium channel resulting in a decrease in heat-induced pain in most of the patients. We derived induced pluripotent stem cell (iPSC) lines from four of five subjects and produced sensory neurons that emulated the clinical phenotype of hyperexcitability and aberrant responses to heat stimuli. When we compared the severity of the clinical phenotype with the hyperexcitability of the iPSC-derived sensory neurons, we saw a trend toward a correlation for individual mutations. The in vitro IEM phenotype was sensitive to Nav1.7 blockers, including the clinical test agent. Given the importance of peripherally expressed sodium channels in many pain conditions, our approach may have broader utility for a wide range of pain and sensory conditions. Copyright © 2016, American Association for the Advancement of Science.

Intraspecific venom variation in the medically significant Southern Pacific Rattlesnake (Crotalus oreganus helleri): biodiscovery, clinical and evolutionary implications.

PubMed

Sunagar, Kartik; Undheim, Eivind A B; Scheib, Holger; Gren, Eric C K; Cochran, Chip; Person, Carl E; Koludarov, Ivan; Kelln, Wayne; Hayes, William K; King, Glenn F; Antunes, Agosthino; Fry, Bryan Grieg

2014-03-17

Due to the extreme variation of venom, which consequently results in drastically variable degrees of neutralization by CroFab antivenom, the management and treatment of envenoming by Crotalus oreganus helleri (the Southern Pacific Rattlesnake), one of the most medically significant snake species in all of North America, has been a clinician's nightmare. This snake has also been the subject of sensational news stories regarding supposed rapid (within the last few decades) evolution of its venom. This research demonstrates for the first time that variable evolutionary selection pressures sculpt the intraspecific molecular diversity of venom components in C. o. helleri. We show that myotoxic β-defensin peptides (aka: crotamines/small basic myotoxic peptides) are secreted in large amounts by all populations. However, the mature toxin-encoding nucleotide regions evolve under the constraints of negative selection, likely as a result of their non-specific mode of action which doesn't enforce them to follow the regime of the classic predator-prey chemical arms race. The hemorrhagic and tissue destroying snake venom metalloproteinases (SVMPs) were secreted in larger amounts by the Catalina Island and Phelan rattlesnake populations, in moderate amounts in the Loma Linda population and in only trace levels by the Idyllwild population. Only the Idyllwild population in the San Jacinto Mountains contained potent presynaptic neurotoxic phospholipase A2 complex characteristic of Mohave Rattlesnake (Crotalus scutulatus) and Neotropical Rattlesnake (Crotalus durissus terrificus). The derived heterodimeric lectin toxins characteristic of viper venoms, which exhibit a diversity of biological activities, including anticoagulation, agonism/antagonism of platelet activation, or procoagulation, appear to have evolved under extremely variable selection pressures. While most lectin α- and β-chains evolved rapidly under the influence of positive Darwinian selection, the β-chain lectin of the Catalina Island population appears to have evolved under the constraint of negative selection. Both lectin chains were conspicuously absent in both the proteomics and transcriptomics of the Idyllwild population. Thus, we not only highlight the tremendous biochemical diversity in C. o. helleri's venom-arsenal, but we also show that they experience remarkably variable strengths of evolutionary selection pressures, within each toxin class among populations and among toxin classes within each population. The mapping of geographical venom variation not only provides additional information regarding venom evolution, but also has direct medical implications by allowing prediction of the clinical effects of rattlesnake bites from different regions. Such information, however, also points to these highly variable venoms as being a rich source of novel toxins which may ultimately prove to be useful in drug design and development. These results have direct implications for the treatment of envenomed patients. The variable venom profile of Crotalus oreganus helleri underscores the biodiscovery potential of novel snake venoms. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

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.

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

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.

Characterization of Pharmacologic and Pharmacokinetic Properties of CCX168, a Potent and Selective Orally Administered Complement 5a Receptor Inhibitor, Based on Preclinical Evaluation and Randomized Phase 1 Clinical Study.

PubMed

Bekker, Pirow; Dairaghi, Daniel; Seitz, Lisa; Leleti, Manmohan; Wang, Yu; Ertl, Linda; Baumgart, Trageen; Shugarts, Sarah; Lohr, Lisa; Dang, Ton; Miao, Shichang; Zeng, Yibin; Fan, Pingchen; Zhang, Penglie; Johnson, Daniel; Powers, Jay; Jaen, Juan; Charo, Israel; Schall, Thomas J

2016-01-01

The complement 5a receptor has been an attractive therapeutic target for many autoimmune and inflammatory disorders. However, development of a selective and potent C5aR antagonist has been challenging. Here we describe the characterization of CCX168 (avacopan), an orally administered selective and potent C5aR inhibitor. CCX168 blocked the C5a binding, C5a-mediated migration, calcium mobilization, and CD11b upregulation in U937 cells as well as in freshly isolated human neutrophils. CCX168 retains high potency when present in human blood. A transgenic human C5aR knock-in mouse model allowed comparison of the in vitro and in vivo efficacy of the molecule. CCX168 effectively blocked migration in in vitro and ex vivo chemotaxis assays, and it blocked the C5a-mediated neutrophil vascular endothelial margination. CCX168 was effective in migration and neutrophil margination assays in cynomolgus monkeys. This thorough in vitro and preclinical characterization enabled progression of CCX168 into the clinic and testing of its safety, tolerability, pharmacokinetic, and pharmacodynamic profiles in a Phase 1 clinical trial in 48 healthy volunteers. CCX168 was shown to be well tolerated across a broad dose range (1 to 100 mg) and it showed dose-dependent pharmacokinetics. An oral dose of 30 mg CCX168 given twice daily blocked the C5a-induced upregulation of CD11b in circulating neutrophils by 94% or greater throughout the entire day, demonstrating essentially complete target coverage. This dose regimen is being tested in clinical trials in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis. Trial Registration ISRCTN registry with trial ID ISRCTN13564773.

Characterization of Pharmacologic and Pharmacokinetic Properties of CCX168, a Potent and Selective Orally Administered Complement 5a Receptor Inhibitor, Based on Preclinical Evaluation and Randomized Phase 1 Clinical Study

PubMed Central

Bekker, Pirow; Dairaghi, Daniel; Seitz, Lisa; Leleti, Manmohan; Wang, Yu; Ertl, Linda; Baumgart, Trageen; Shugarts, Sarah; Lohr, Lisa; Dang, Ton; Miao, Shichang; Zeng, Yibin; Fan, Pingchen; Zhang, Penglie; Johnson, Daniel; Powers, Jay; Jaen, Juan; Charo, Israel; Schall, Thomas J.

2016-01-01

The complement 5a receptor has been an attractive therapeutic target for many autoimmune and inflammatory disorders. However, development of a selective and potent C5aR antagonist has been challenging. Here we describe the characterization of CCX168 (avacopan), an orally administered selective and potent C5aR inhibitor. CCX168 blocked the C5a binding, C5a-mediated migration, calcium mobilization, and CD11b upregulation in U937 cells as well as in freshly isolated human neutrophils. CCX168 retains high potency when present in human blood. A transgenic human C5aR knock-in mouse model allowed comparison of the in vitro and in vivo efficacy of the molecule. CCX168 effectively blocked migration in in vitro and ex vivo chemotaxis assays, and it blocked the C5a-mediated neutrophil vascular endothelial margination. CCX168 was effective in migration and neutrophil margination assays in cynomolgus monkeys. This thorough in vitro and preclinical characterization enabled progression of CCX168 into the clinic and testing of its safety, tolerability, pharmacokinetic, and pharmacodynamic profiles in a Phase 1 clinical trial in 48 healthy volunteers. CCX168 was shown to be well tolerated across a broad dose range (1 to 100 mg) and it showed dose-dependent pharmacokinetics. An oral dose of 30 mg CCX168 given twice daily blocked the C5a-induced upregulation of CD11b in circulating neutrophils by 94% or greater throughout the entire day, demonstrating essentially complete target coverage. This dose regimen is being tested in clinical trials in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis. Trial Registration ISRCTN registry with trial ID ISRCTN13564773. PMID:27768695

The guinea pig ileum lacks the direct, high-potency, M(2)-muscarinic, contractile mechanism characteristic of the mouse ileum.

PubMed

Griffin, Michael T; Matsui, Minoru; Ostrom, Rennolds S; Ehlert, Frederick J

2009-10-01

We explored whether the M(2) muscarinic receptor in the guinea pig ileum elicits a highly potent, direct-contractile response, like that from the M(3) muscarinic receptor knockout mouse. First, we characterized the irreversible receptor-blocking activity of 4-DAMP mustard in ileum from muscarinic receptor knockout mice to verify its M(3) selectivity. Then, we used 4-DAMP mustard to inactivate M(3) responses in the guinea pig ileum to attempt to reveal direct, M(2) receptor-mediated contractions. The muscarinic agonist, oxotremorine-M, elicited potent contractions in ileum from wild-type, M(2) receptor knockout, and M(3) receptor knockout mice characterized by negative log EC(50) (pEC (50)) values +/- SEM of 6.75 +/- 0.03, 6.26 +/- 0.05, and 6.99 +/- 0.08, respectively. The corresponding E (max) values in wild-type and M(2) receptor knockout mice were approximately the same, but that in the M(3) receptor knockout mouse was only 36% of wild type. Following 4-DAMP mustard treatment, the concentration-response curve of oxotremorine-M in wild-type ileum resembled that of the M(3) knockout mouse in terms of its pEC (50), E (max), and inhibition by selective muscarinic antagonists. Thus, 4-DAMP mustard treatment appears to inactivate M(3) responses selectively and renders the muscarinic contractile behavior of the wild-type ileum similar to that of the M(3) knockout mouse. Following 4-DAMP mustard treatment, the contractile response of the guinea pig ileum to oxotremorine-M exhibited low potency and a competitive-antagonism profile consistent with an M(3) response. The guinea pig ileum, therefore, lacks a direct, highly potent, M(2)-contractile component but may have a direct, lower potency M(2) component.

Evaluation of potent inhibitors of dihydrofolate reductase in a culture model for growth of Pneumocystis carinii.

PubMed

Bartlett, M S; Shaw, M; Navaran, P; Smith, J W; Queener, S F

1995-11-01

Many antifolates are known to inhibit dihydrofolate reductase from murine Pneumocystis carinii, with 50% inhibitory concentrations (IC50s) ranging from 10(-4) to 10(-11) M. The relationship of the potency against isolated enzyme to the potency against intact murine P. carinii cells was explored with 17 compounds that had proven selectivity for or potency against P. carinii dihydrofolate reductase. Pyrimethamine and one analog were inhibitory to P. carinii in culture at concentrations two to seven times the IC50s for the enzyme, suggesting that the compounds may enter P. carinii cells in culture. Methotrexate was a potent inhibitor of P. carinii dihydrofolate reductase, but the concentrations effective in culture were more than 1,000-fold higher than IC50s for the enzyme, since P. carinii lacks an uptake system for methotrexate. Analogs of methotrexate in which chlorine, bromine, or iodine was added to the phenyl ring had improved potency against the isolated enzyme but were markedly less effective in culture; polyglutamation also lowered the activity in culture but improved activity against the enzyme. Substitution of a naphthyl group for the phenyl group of methotrexate produced a compound with improved activity against the enzyme (IC50, 0.00019 microM) and excellent activity in culture (IC50, 0.1 microM). One trimetrexate analog in which an aspartate or a chlorine replaced two of the methoxy groups of trimetrexate was much more potent and was much more selective toward P. carinii dihydrofolate reductase than trimetrexate; this analog was also as active as trimetrexate in culture. These studies suggest that modifications of antifolate structures can be made that facilitate activity against intact organisms while maintaining the high degrees of potency and the selectivities of the agents can be made.

Extremely Selective Attention: Eye-Tracking Studies of the Dynamic Allocation of Attention to Stimulus Features in Categorization

ERIC Educational Resources Information Center

Blair, Mark R.; Watson, Marcus R.; Walshe, R. Calen; Maj, Fillip

2009-01-01

Humans have an extremely flexible ability to categorize regularities in their environment, in part because of attentional systems that allow them to focus on important perceptual information. In formal theories of categorization, attention is typically modeled with weights that selectively bias the processing of stimulus features. These theories…

Selective delivery of 2-hydroxy APA to Trypanosoma brucei using the melamine motif

PubMed Central

Klee, Nina; Wong, Pui Ee; Baragaña, Beatriz; Mazouni, Farah El; Phillips, Margaret A.; Barrett, Michael P.; Gilbert, Ian H.

2010-01-01

Trypanosoma brucei, the parasite that causes human African trypanosomiasis, is auxotrophic for purines and has specialist nucleoside transporters to import these metabolites. In particular, the P2 aminopurine transporter can also selectively accumulate melamine derivatives. In this Letter, we report the coupling of the melamine moiety to 2-hydroxy APA, a potent ornithine decarboxylase inhibitor, with the aim of selectively delivering this compound to the parasite. The best compound described here shows an increased in vitro trypanocidal activity compared with the parent. PMID:20615694

Structure-based drug design of RN486, a potent and selective Bruton's tyrosine kinase (BTK) inhibitor, for the treatment of rheumatoid arthritis.

PubMed

Lou, Yan; Han, Xiaochun; Kuglstatter, Andreas; Kondru, Rama K; Sweeney, Zachary K; Soth, Michael; McIntosh, Joel; Litman, Renee; Suh, Judy; Kocer, Buelent; Davis, Dana; Park, Jaehyeon; Frauchiger, Sandra; Dewdney, Nolan; Zecic, Hasim; Taygerly, Joshua P; Sarma, Keshab; Hong, Junbae; Hill, Ronald J; Gabriel, Tobias; Goldstein, David M; Owens, Timothy D

2015-01-08

Structure-based drug design was used to guide the optimization of a series of selective BTK inhibitors as potential treatments for Rheumatoid arthritis. Highlights include the introduction of a benzyl alcohol group and a fluorine substitution, each of which resulted in over 10-fold increase in activity. Concurrent optimization of drug-like properties led to compound 1 (RN486) ( J. Pharmacol. Exp. Ther. 2012 , 341 , 90 ), which was selected for advanced preclinical characterization based on its favorable properties.

Acalabrutinib (ACP-196): a selective second-generation BTK inhibitor.

PubMed

Wu, Jingjing; Zhang, Mingzhi; Liu, Delong

2016-03-09

More and more targeted agents become available for B cell malignancies with increasing precision and potency. The first-in-class Bruton's tyrosine kinase (BTK) inhibitor, ibrutinib, has been in clinical use for the treatment of chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom's macroglobulinemia. More selective BTK inhibitors (ACP-196, ONO/GS-4059, BGB-3111, CC-292) are being explored. Acalabrutinib (ACP-196) is a novel irreversible second-generation BTK inhibitor that was shown to be more potent and selective than ibrutinib. This review summarized the preclinical research and clinical data of acalabrutinib.

Design and synthesis of novel pyrimidine analogs as highly selective, non-covalent BTK inhibitors.

PubMed

Kawahata, Wataru; Asami, Tokiko; Irie, Takayuki; Sawa, Masaaki

2018-01-15

BTK is a promising target for the treatment of multiple diseases such as B cell malignances, asthma, and rheumatoid arthritis. Here, we report the discovery of a series of novel pyrimidine analogs as potent, highly selective, non-covalent inhibitors of BTK. Compound 25d demonstrated higher affinity to an unactivated conformation of BTK that resulted in an excellent kinase selectivity. Compound 25d showed a good oral bioavailability in mice, and significantly inhibits the PCA reaction in mice. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

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

2015-02-01

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

Synthesis of Novel Synthetic Vitamin K Analogues Prepared by Introduction of a Heteroatom and a Phenyl Group That Induce Highly Selective Neuronal Differentiation of Neuronal Progenitor Cells.

PubMed

Kimura, Kimito; Hirota, Yoshihisa; Kuwahara, Shigefumi; Takeuchi, Atsuko; Tode, Chisato; Wada, Akimori; Osakabe, Naomi; Suhara, Yoshitomo

2017-03-23

We synthesized novel vitamin K 2 analogues that incorporated a heteroatom and an aromatic ring in the side chain and evaluated their effect on the selective differentiation of neuronal progenitor cells into neurons in vitro. The results showed that a menaquinone-2 analogue bearing a p-fluoroaniline had the most potent activity, which was more than twice as great as the control. In addition, the neuronal selectivity was more than 3 times greater than the control.

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

Tsoua, Hwei-Ru; MacEwana, Gloria; Birnberga, Gary

We discovered 2-(4-substituted-pyrrolo[2,3-b]pyridin-3-yl)methylene-4-hydroxybenzofuran-3(2H)-ones as potent and selective ATP-competitive inhibitors of the mammalian target of rapamycin (mTOR). Since phenolic OH groups pose metabolic liability, one of the two hydroxyl groups was selectively removed. The SAR data showed the structural features necessary for subnanomolar inhibitory activity against mTOR kinase as well as selectivity over PI3K?. An X-ray co-crystal structure of one inhibitor with the mTOR-related PI3K? revealed the key hydrogen bonding interactions.

Discovery of a Selective S1P1 Receptor Agonist Efficacious at Low Oral Dose and Devoid of Effects on Heart Rate.

PubMed

Demont, Emmanuel H; Andrews, Benjamin I; Bit, Rino A; Campbell, Colin A; Cooke, Jason W B; Deeks, Nigel; Desai, Sapna; Dowell, Simon J; Gaskin, Pam; Gray, James R J; Haynes, Andrea; Holmes, Duncan S; Kumar, Umesh; Morse, Mary A; Osborne, Greg J; Panchal, Terry; Patel, Bela; Perboni, Alcide; Taylor, Simon; Watson, Robert; Witherington, Jason; Willis, Robert

2011-06-09

Gilenya (fingolimod, FTY720) was recently approved by the U.S. FDA for the treatment of patients with remitting relapsing multiple sclerosis (RRMS). It is a potent agonist of four of the five sphingosine 1-phosphate (S1P) G-protein-coupled receptors (S1P1 and S1P3-5). It has been postulated that fingolimod's efficacy is due to S1P1 agonism, while its cardiovascular side effects (transient bradycardia and hypertension) are due to S1P3 agonism. We have discovered a series of selective S1P1 agonists, which includes 3-[6-(5-{3-cyano-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-5-methyl-3,4-dihydro-2(1H)-isoquinolinyl]propanoate, 20, a potent, S1P3-sparing, orally active S1P1 agonist. Compound 20 is as efficacious as fingolimod in a collagen-induced arthritis model and shows excellent pharmacokinetic properties preclinically. Importantly, the selectivity of 20 against S1P3 is responsible for an absence of cardiovascular signal in telemetered rats, even at high dose levels.

Discovery of a Selective S1P1 Receptor Agonist Efficacious at Low Oral Dose and Devoid of Effects on Heart Rate

PubMed Central

2011-01-01

Gilenya (fingolimod, FTY720) was recently approved by the U.S. FDA for the treatment of patients with remitting relapsing multiple sclerosis (RRMS). It is a potent agonist of four of the five sphingosine 1-phosphate (S1P) G-protein-coupled receptors (S1P1 and S1P3−5). It has been postulated that fingolimod's efficacy is due to S1P1 agonism, while its cardiovascular side effects (transient bradycardia and hypertension) are due to S1P3 agonism. We have discovered a series of selective S1P1 agonists, which includes 3-[6-(5-{3-cyano-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-5-methyl-3,4-dihydro-2(1H)-isoquinolinyl]propanoate, 20, a potent, S1P3-sparing, orally active S1P1 agonist. Compound 20 is as efficacious as fingolimod in a collagen-induced arthritis model and shows excellent pharmacokinetic properties preclinically. Importantly, the selectivity of 20 against S1P3 is responsible for an absence of cardiovascular signal in telemetered rats, even at high dose levels. PMID:24900328

Synthesis of ent-BE-43547A1 reveals a potent hypoxia-selective anticancer agent and uncovers the biosynthetic origin of the APD-CLD natural products.

PubMed

Villadsen, Nikolaj L; Jacobsen, Kristian M; Keiding, Ulrik B; Weibel, Esben T; Christiansen, Bjørn; Vosegaard, Thomas; Bjerring, Morten; Jensen, Frank; Johannsen, Mogens; Tørring, Thomas; Poulsen, Thomas B

2017-03-01

Tumour hypoxia is speculated to be a key driver of therapeutic resistance and metastatic dissemination. Consequently, the discovery of new potent agents that selectively target the hypoxic cell population may reveal new and untapped antitumour mechanisms. Here we demonstrate that the BE-43547 subclass of the APD-CLD (amidopentadienoate-containing cyclolipodepsipeptides) natural products possesses highly hypoxia-selective growth-inhibitory activity against pancreatic cancer cells. To enable this discovery, we have developed the first synthesis of the BE-43547-macrocyclic scaffold in 16 steps (longest linear sequence), which also allowed access to the full panel of relative stereoisomers and ultimately to the assignment of stereochemical configuration. Discrepancies between the spectroscopic signatures of the synthetic compounds with that originally reported for the BE-43547 members stimulated us to re-isolate the natural product from a BE-43547-producing microorganism during which we elucidated the biosynthetic gene clusters for the BE-43547 family as well as for all other known APD-CLDs. Our studies underline the exciting possibilities for the further development of the anticancer activities of these natural products.

Synthesis of ent-BE-43547A1 reveals a potent hypoxia-selective anticancer agent and uncovers the biosynthetic origin of the APD-CLD natural products

NASA Astrophysics Data System (ADS)

Villadsen, Nikolaj L.; Jacobsen, Kristian M.; Keiding, Ulrik B.; Weibel, Esben T.; Christiansen, Bjørn; Vosegaard, Thomas; Bjerring, Morten; Jensen, Frank; Johannsen, Mogens; Tørring, Thomas; Poulsen, Thomas B.

2017-03-01

Tumour hypoxia is speculated to be a key driver of therapeutic resistance and metastatic dissemination. Consequently, the discovery of new potent agents that selectively target the hypoxic cell population may reveal new and untapped antitumour mechanisms. Here we demonstrate that the BE-43547 subclass of the APD-CLD (amidopentadienoate-containing cyclolipodepsipeptides) natural products possesses highly hypoxia-selective growth-inhibitory activity against pancreatic cancer cells. To enable this discovery, we have developed the first synthesis of the BE-43547-macrocyclic scaffold in 16 steps (longest linear sequence), which also allowed access to the full panel of relative stereoisomers and ultimately to the assignment of stereochemical configuration. Discrepancies between the spectroscopic signatures of the synthetic compounds with that originally reported for the BE-43547 members stimulated us to re-isolate the natural product from a BE-43547-producing microorganism during which we elucidated the biosynthetic gene clusters for the BE-43547 family as well as for all other known APD-CLDs. Our studies underline the exciting possibilities for the further development of the anticancer activities of these natural products.

Design, Synthesis and Pharmacological Evaluation of Novel Vanadium-Containing Complexes as Antidiabetic Agents

PubMed Central

Fedorova, Elena V.; Buryakina, Anna V.; Zakharov, Alexey V.; Filimonov, Dmitry A.; Lagunin, Alexey A.; Poroikov, Vladimir V.

2014-01-01

Based on the data about structure and antidiabetic activity of twenty seven vanadium and zinc coordination complexes collected from literature we developed QSAR models using the GUSAR program. These QSAR models were applied to 10 novel vanadium coordination complexes designed in silico in order to predict their hypoglycemic action. The five most promising substances with predicted potent hypoglycemic action were selected for chemical synthesis and pharmacological evaluation. The selected coordination vanadium complexes were synthesized and tested in vitro and in vivo for their hypoglycemic activities and acute rat toxicity. Estimation of acute rat toxicity of these five vanadium complexes was performed using a freely available web-resource (http://way2drug.com/GUSAR/acutoxpredict.html). It has shown that the selected compounds belong to the class of moderate toxic pharmaceutical agents, according to the scale of Hodge and Sterner. Comparison with the predicted data has demonstrated a reasonable correspondence between the experimental and predicted values of hypoglycemic activity and toxicity. Bis{tert-butyl[amino(imino)methyl]carbamato}oxovanadium (IV) and sodium(2,2′-Bipyridyl)oxo-diperoxovanadate(V) octahydrate were identified as the most potent hypoglycemic agents among the synthesized compounds. PMID:25057899

Indanones as high-potency reversible inhibitors of monoamine oxidase.

PubMed

Mostert, Samantha; Petzer, Anél; Petzer, Jacobus P

2015-05-01

Recent reports document that α-tetralone (3,4-dihydro-2H-naphthalen-1-one) is an appropriate scaffold for the design of high-potency monoamine oxidase (MAO) inhibitors. Based on the structural similarity between α-tetralone and 1-indanone, the present study involved synthesis of 34 1-indanone and related indane derivatives as potential inhibitors of recombinant human MAO-A and MAO-B. The results show that C6-substituted indanones are particularly potent and selective MAO-B inhibitors, with IC50 values ranging from 0.001 to 0.030 μM. C5-Substituted indanone and indane derivatives are comparatively weaker MAO-B inhibitors. Although the 1-indanone and indane derivatives are selective inhibitors of the MAO-B isoform, a number of homologues are also potent MAO-A inhibitors, with three homologues possessing IC50 values <0.1 μM. Dialysis of enzyme-inhibitor mixtures further established a selected 1-indanone as a reversible MAO inhibitor with a competitive mode of inhibition. It may be concluded that 1-indanones are promising leads for the design of therapies for neurodegenerative and neuropsychiatric disorders such as Parkinson's disease and depression. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibition of Cancer-Associated Mutant Isocitrate Dehydrogenases: Synthesis, Structure–Activity Relationship, and Selective Antitumor Activity

PubMed Central

2015-01-01

Mutations of isocitrate dehydrogenase 1 (IDH1) are frequently found in certain cancers such as glioma. Different from the wild-type (WT) IDH1, the mutant enzymes catalyze the reduction of α-ketoglutaric acid to d-2-hydroxyglutaric acid (D2HG), leading to cancer initiation. Several 1-hydroxypyridin-2-one compounds were identified to be inhibitors of IDH1(R132H). A total of 61 derivatives were synthesized, and their structure–activity relationships were investigated. Potent IDH1(R132H) inhibitors were identified with Ki values as low as 140 nM, while they possess weak or no activity against WT IDH1. Activities of selected compounds against IDH1(R132C) were found to be correlated with their inhibitory activities against IDH1(R132H), as well as cellular production of D2HG, with R2 of 0.83 and 0.73, respectively. Several inhibitors were found to be permeable through the blood–brain barrier in a cell-based model assay and exhibit potent and selective activity (EC50 = 0.26–1.8 μM) against glioma cells with the IDH1 R132H mutation. PMID:25271760

Potent and selective mediators of cholesterol efflux

DOEpatents

Bielicki, John K; Johansson, Jan

2015-03-24

The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

Discovery of a 1,2-bis(3-indolyl)ethane that selectively inhibits the pyruvate kinase of methicillin-resistant Staphylococcus aureus over human isoforms.

PubMed

Zoraghi, Roya; Campbell, Sara; Kim, Catrina; Dullaghan, Edie M; Blair, Lachlan M; Gillard, Rachel M; Reiner, Neil E; Sperry, Jonathan

2014-11-01

Methicillin-resistant Staphylococcus aureus pyruvate kinase (MRSA PK) has recently been identified as a target for development of novel antibacterial agents. Testing a series of 1,2-bis(3-indolyl)ethanes against MRSA PK has led to the discovery of a potent inhibitor that is selective over human isoforms. Copyright © 2014 Elsevier Ltd. All rights reserved.

PASS-predicted design, synthesis and biological evaluation of cyclic nitrones as nootropics.

PubMed

Marwaha, Alka; Goel, R K; Mahajan, Mohinder P

2007-09-15

Out of 400 virtually designed imidazoline N-oxides, five cyclic nitrones were selected on the basis of PASS prediction as potent nootropics and were evaluated for their biological activities in albino mice. The selected N-alkyl and aryl-substituted nitrones were found to be excellent nootropics. A series of lead compounds acting as cognition enhancers have been provided, which can be further exploited in search of such New Chemical Entities (NCEs).

Discovery of novel Tetrahydrobenzo[b]thiophene and pyrrole based scaffolds as potent and selective CB2 receptor ligands: The structural elements controlling binding affinity, selectivity and functionality.

PubMed

Osman, Noha A; Ligresti, Alessia; Klein, Christian D; Allarà, Marco; Rabbito, Alessandro; Di Marzo, Vincenzo; Abouzid, Khaled A; Abadi, Ashraf H

2016-10-21

CB2-based therapeutics show strong potential in the treatment of diverse diseases such as inflammation, multiple sclerosis, pain, immune-related disorders, osteoporosis and cancer, without eliciting the typical neurobehavioral side effects of CB1 ligands. For this reason, research activities are currently directed towards the development of CB2 selective ligands. Herein, the synthesis of novel heterocyclic-based CB2 selective compounds is reported. A set of 2,5-dialkyl-1-phenyl-1H-pyrrole-3-carboxamides, 5-subtituted-2-(acylamino)/(2-sulphonylamino)-thiophene-3-carboxylates and 2-(acylamino)/(2-sulphonylamino)-tetrahydrobenzo[b]thiophene-3-carboxylates were synthesized. Biological results revealed compounds with remarkably high CB2 binding affinity and CB2/CB1 subtype selectivity. Compound 19a and 19b from the pyrrole series exhibited the highest CB2 receptor affinity (Ki = 7.59 and 6.15 nM, respectively), as well as the highest CB2/CB1 subtype selectivity (∼70 and ∼200-fold, respectively). In addition, compound 6b from the tetrahydrobenzo[b]thiophene series presented the most potent and selective CB2 ligand in this series (Ki = 2.15 nM and CB2 subtype selectivity of almost 500-fold over CB1). Compound 6b showed a full agonism, while compounds 19a and 19b acted as inverse agonists when tested in an adenylate cyclase assay. The present findings thus pave the way to the design and optimization of heterocyclic-based scaffolds with lipophilic carboxamide and/or retroamide substituent that can be exploited as potential CB2 receptor activity modulators. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

3-Hydroxypyrimidine-2,4-dione-5-N-benzylcarboxamides potently inhibit HIV-1 integrase and RNase H

PubMed Central

Wu, Bulan; Tang, Jing; Wilson, Daniel J.; Huber, Andrew D.; Casey, Mary C.; Ji, Juan; Kankanala, Jayakanth; Xie, Jiashu; Sarafianos, Stefan G.; Wang, Zhengqiang

2016-01-01

Resistance selection by human immunodeficiency virus (HIV) towards known drug regimens necessitates the discovery of structurally novel antivirals with a distinct resistance profile. Based on our previously reported 3-hydroxypyrimidine-2,4-dione (HPD) core we have designed and synthesized a new integrase strand transfer (INST) inhibitor type featuring a 5-N-benzylcarboxamide moiety. Significantly, the 6-alkylamino variant of this new chemotype consistently conferred low nanomolar inhibitory activity against HIV-1. Extended antiviral testing against a few raltegravir-resistant HIV-1 clones revealed a resistance profile similar to that of the second generation INST inhibitor (INSTIs) dolutegravir. Although biochemical testing and molecular modeling also strongly corroborate the inhibition of INST as the antiviral mechanism of action, selected antiviral analogues also potently inhibited reverse transcriptase (RT) associated RNase H, implying potential dual target inhibition. In vitro ADME assays demonstrated that this novel chemotype possesses largely favorable physicochemical properties suitable for further development. PMID:27283261

Transformation of Human Cathelicidin LL-37 into Selective, Stable, and Potent Antimicrobial Compounds

PubMed Central

2015-01-01

This Letter reports a family of novel antimicrobial compounds obtained by combining peptide library screening with structure-based design. Library screening led to the identification of a human LL-37 peptide resistant to chymotrypsin. This d-amino-acid-containing peptide template was active against Escherichia coli but not methicillin-resistant Staphylococcus aureus (MRSA). It possesses a unique nonclassic amphipathic structure with hydrophobic defects. By repairing the hydrophobic defects, the peptide (17BIPHE2) gained activity against the ESKAPE pathogens, including Enterococcus faecium, S. aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter species. In vitro, 17BIPHE2 could disrupt bacterial membranes and bind to DNA. In vivo, the peptide prevented staphylococcal biofilm formation in a mouse model of catheter-associated infection. Meanwhile, it boosted the innate immune response to further combat the infection. Because these peptides are potent, cell-selective, and stable to several proteases, they may be utilized to combat one or more ESKAPE pathogens. PMID:25061850

Selective and Specific Inhibition of the Plasmodium falciparum Lysyl-tRNA Synthetase by the Fungal Secondary Metabolite Cladosporin

PubMed Central

Hoepfner, Dominic; McNamara, Case W.; Lim, Chek Shik; Studer, Christian; Riedl, Ralph; Aust, Thomas; McCormack, Susan L.; Plouffe, David M.; Meister, Stephan; Schuierer, Sven; Plikat, Uwe; Hartmann, Nicole; Staedtler, Frank; Cotesta, Simona; Schmitt, Esther K.; Petersen, Frank; Supek, Frantisek; Glynne, Richard J.; Tallarico, John A.; Porter, Jeffrey A.; Fishman, Mark C.; Bodenreider, Christophe; Diagana, Thierry T.; Movva, N. Rao; Winzeler, Elizabeth A.

2012-01-01

Summary With renewed calls for malaria eradication, next-generation antimalarials need be active against drug-resistant parasites and efficacious against both liver- and blood-stage infections. We screened a natural product library to identify inhibitors of Plasmodium falciparum blood- and liver-stage proliferation. Cladosporin, a fungal secondary metabolite whose target and mechanism of action are not known for any species, was identified as having potent, nanomolar, antiparasitic activity against both blood and liver stages. Using postgenomic methods, including a yeast deletion strains collection, we show that cladosporin specifically inhibits protein synthesis by directly targeting P. falciparum cytosolic lysyl-tRNA synthetase. Further, cladosporin is >100-fold more potent against parasite lysyl-tRNA synthetase relative to the human enzyme, which is conferred by the identity of two amino acids within the enzyme active site. Our data indicate that lysyl-tRNA synthetase is an attractive, druggable, antimalarial target that can be selectively inhibited. PMID:22704625

Selective and specific inhibition of the plasmodium falciparum lysyl-tRNA synthetase by the fungal secondary metabolite cladosporin.

PubMed

Hoepfner, Dominic; McNamara, Case W; Lim, Chek Shik; Studer, Christian; Riedl, Ralph; Aust, Thomas; McCormack, Susan L; Plouffe, David M; Meister, Stephan; Schuierer, Sven; Plikat, Uwe; Hartmann, Nicole; Staedtler, Frank; Cotesta, Simona; Schmitt, Esther K; Petersen, Frank; Supek, Frantisek; Glynne, Richard J; Tallarico, John A; Porter, Jeffrey A; Fishman, Mark C; Bodenreider, Christophe; Diagana, Thierry T; Movva, N Rao; Winzeler, Elizabeth A

2012-06-14

With renewed calls for malaria eradication, next-generation antimalarials need be active against drug-resistant parasites and efficacious against both liver- and blood-stage infections. We screened a natural product library to identify inhibitors of Plasmodium falciparum blood- and liver-stage proliferation. Cladosporin, a fungal secondary metabolite whose target and mechanism of action are not known for any species, was identified as having potent, nanomolar, antiparasitic activity against both blood and liver stages. Using postgenomic methods, including a yeast deletion strains collection, we show that cladosporin specifically inhibits protein synthesis by directly targeting P. falciparum cytosolic lysyl-tRNA synthetase. Further, cladosporin is >100-fold more potent against parasite lysyl-tRNA synthetase relative to the human enzyme, which is conferred by the identity of two amino acids within the enzyme active site. Our data indicate that lysyl-tRNA synthetase is an attractive, druggable, antimalarial target that can be selectively inhibited. Copyright © 2012 Elsevier Inc. All rights reserved.

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

A possible role for endogenous glucocorticoids in orchiectomy-induced atrophy of the rat levator ani muscle - Studies with RU 38486, a potent and selective antiglucocorticoid

NASA Technical Reports Server (NTRS)

Konagaya, Masaaki; Max, Stephen R.

1986-01-01

RU38486, a potent and selective antiglucocorticoid, was employed to study a possible role for endogenous glucocorticoids in atrophy of the levator ani muscle secondary to castration of male rats. RU38486 was shown to block (3H) triamcinolone acetonide binding to cytosol from levator ani muscle. Daily oral administration of RU38486 to castrated rats partially prevented atrophy of the levator ani muscle, as well as a decrease in RNA concentration. In a control group receiving RU38486 alone, the levator ani underwent significant 20 percent hypertrophy. Administration of exogenous dexamethasone also caused pronounced atrophy of the levator ani muscle. This atrophy was prevented, to a significant degree, by simultaneous oral administration of Ru38486. It is concluded that endogenous glucocorticoids, the actions of which are blocked by RU38486, may be involved in regulation of the mass of the levator ani muscle in intact rats.

The insecticide target in the PSST subunit of complex I.

PubMed

Schuler, F; Casida, J E

2001-10-01

Current insecticides have been selected by sifting and winnowing hundreds of thousands of synthetic chemicals and natural products to obtain commercial preparations of optimal effectiveness and safety. This process has often ended up with compounds of high potency as inhibitors of the electron transport chain and more specifically of complex I (NADH:ubiquinone oxidoreductase). Many classes of chemicals are involved and the enzyme is one of the most complicated known, with 43 subunits catalyzing electron transfer from NADH to ubiquinone through flavin mononucleotide and up to eight iron-sulfur clusters. We used a potent photoaffinity ligand, (trifluoromethyl)diazirinyl[3H]pyridaben, to localize the insecticide target to a single high-affinity site in the PSST subunit that couples electron transfer from iron-sulfur cluster N2 to ubiquinone. Most importantly, all of the potent complex I-inhibiting pesticides, despite their great structural diversity, compete for this same specific binding domain in PSST. Finding their common mode of action and target provides insight into shared toxicological features and potential selection for resistant pests.

Synthesis, alkaline phosphatase inhibition studies and molecular docking of novel derivatives of 4-quinolones.

PubMed

Miliutina, Mariia; Ejaz, Syeda Abida; Khan, Shafi Ullah; Iaroshenko, Viktor O; Villinger, Alexander; Iqbal, Jamshed; Langer, Peter

2017-01-27

New and convenient methods for the functionalization of the 4-quinolone scaffold at positions C-1, C-3 and C-6 were developed. The 4-quinolone derivatives were evaluated for their inhibitory potential on alkaline phosphatase isozymes. Most of the compounds exhibit excellent inhibitory activity and moderate selectivity. The IC 50 values on tissue non-specific alkaline phosphatase (TNAP) were in the range of 1.34 ± 0.11 to 44.80 ± 2.34 μM, while the values on intestinal alkaline phosphatase (IAP) were in the range of 1.06 ± 0.32 to 192.10 ± 3.78 μM. The most active derivative exhibits a potent inhibition on IAP with a ≈14 fold higher selectivity as compared to TNAP. Furthermore, molecular docking calculations were performed for the most potent inhibitors to show their binding interactions within the active site of the respective enzymes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Visualizing Trumps Vision in Training Attention.

PubMed

Reinhart, Robert M G; McClenahan, Laura J; Woodman, Geoffrey F

2015-07-01

Mental imagery can have powerful training effects on behavior, but how this occurs is not well understood. Here we show that even a single instance of mental imagery can improve attentional selection of a target more effectively than actually practicing visual search. By recording subjects' brain activity, we found that these imagery-induced training effects were due to perceptual attention being more effectively focused on targets following imagined training. Next, we examined the downside of this potent training by changing the target after several trials of training attention with imagery and found that imagined search resulted in more potent interference than actual practice following these target changes. Finally, we found that proactive interference from task-irrelevant elements in the visual displays appears to underlie the superiority of imagined training relative to actual practice. Our findings demonstrate that visual attention mechanisms can be effectively trained to select target objects in the absence of visual input, and this results in more effective control of attention than practicing the task itself. © The Author(s) 2015.

Discovery of potent cytotoxic ortho-aryl chalcones as new scaffold targeting tubulin and mitosis with affinity-based fluorescence.

PubMed

Zhu, Cuige; Zuo, Yinglin; Wang, Ruimin; Liang, Baoxia; Yue, Xin; Wen, Gesi; Shang, Nana; Huang, Lei; Chen, Yu; Du, Jun; Bu, Xianzhang

2014-08-14

A series of new ortho-aryl chalcones have been designed and synthesized. Many of these compounds were found to exhibit significant antiproliferation activity toward a panel of cancer cell lines. Selected compounds show potent cytotoxicity against several drug resistant cell lines including paclitaxel (Taxol) resistant human ovarian carcinoma cells, vincristine resistant human ileocecum carcinoma cells, and doxorubicin resistant human breast carcinoma cells. Further investigation revealed that active analogues could inhibit the microtubule polymerization by binding to colchicine site and thus induce multipolar mitosis, G2/M phase arrest, and apoptosis of cancer cells. Furthermore, affinity-based fluorescence enhancement was observed during the binding of active compounds with tubulin, which greatly facilitated the determination of tubulin binding site of the compounds. Finally, selected compound 26 was found to exhibit obvious in vivo antitumor activity in A549 tumor xenografts model. Our systematic studies implied a new scaffold targeting tubulin and mitosis for novel antitumor drug discovery.

A possible role for endogenous glucocorticoids in orchiectomy-induced atrophy of the rat levator ani muscle: Studies with RU38486, a potent and selective antiglucocorticoid

NASA Technical Reports Server (NTRS)

Konagaya, M.; Max, S. R.

1985-01-01

RU38486, a potent and selective antiglucocorticoid, was employed to study a possible role for endogenous glucocorticoids in atrophy of the levator ani muscle secondary to castration of male rats. RU38486 was shown to block (3H) triamcinolone acetonide binding to cytosol from levator ani muscle. Daily oral administration of RU38486 to castrated rats partially prevented atrophy of the levator ani muscle, as well as a decrease in RNA concentration. In a control group receiving RU38486 alone, the levator ani underwent significant (20%) hypertrophy. Administration of exogenous dexamethasone also caused pronounced atrophy of the levator ani muscle. This atrophy was prevented, to a significant degree, by simultaneous oral administration of RU38486. It is concluded that endogenous glucocorticoids, the actions of which are blocked by RU38486, may be involved in regulation of the mass of the levator ani muscle in intact rats.

Fragment-based discovery of potent inhibitors of the anti-apoptotic MCL-1 protein.

PubMed

Petros, Andrew M; Swann, Steven L; Song, Danying; Swinger, Kerren; Park, Chang; Zhang, Haichao; Wendt, Michael D; Kunzer, Aaron R; Souers, Andrew J; Sun, Chaohong

2014-03-15

Apoptosis is regulated by the BCL-2 family of proteins, which is comprised of both pro-death and pro-survival members. Evasion of apoptosis is a hallmark of malignant cells. One way in which cancer cells achieve this evasion is thru overexpression of the pro-survival members of the BCL-2 family. Overexpression of MCL-1, a pro-survival protein, has been shown to be a resistance factor for Navitoclax, a potent inhibitor of BCL-2 and BCL-XL. Here we describe the use of fragment screening methods and structural biology to drive the discovery of novel MCL-1 inhibitors from two distinct structural classes. Specifically, cores derived from a biphenyl sulfonamide and salicylic acid were uncovered in an NMR-based fragment screen and elaborated using high throughput analog synthesis. This culminated in the discovery of selective and potent inhibitors of MCL-1 that may serve as promising leads for medicinal chemistry optimization efforts. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Dexamethasone potently enhances phorbol ester-induced IL-1beta gene expression and nuclear factor NF-kappaB activation.

PubMed

Wang, Y; Zhang, J J; Dai, W; Lei, K Y; Pike, J W

1997-07-15

The synthetic glucocorticoid dexamethasone, an immunosuppressive and anti-inflammatory agent, was investigated for its effect on PMA-mediated expression of the inflammatory cytokine IL-1beta in the human monocytic leukemic cell line THP-1. PMA alone induced the production of low levels of IL-1beta in THP-1 cells, whereas dexamethasone alone had no effect. However, dexamethasone potently enhanced PMA-mediated IL-1beta production. Using a selective and potent inhibitor of protein kinase C, we found that synergistic interaction between PMA and dexamethasone requires protein kinase C activation. PMA has been known to activate nuclear factor NF-kappaB in THP-1 cells. Using an oligonucleotide probe corresponding to an NF-kappaB DNA-binding motif of the IL-1beta gene promoter in gel electrophoresis mobility shift assays, we demonstrated that PMA-induced NF-kappaB activation was greatly potentiated by dexamethasone. Our results indicate that glucocorticoids can be positive regulators of inflammatory cytokine gene expression during monocytic cell differentiation.

Discovery of novel DAPY-IAS hybrid derivatives as potential HIV-1 inhibitors using molecular hybridization based on crystallographic overlays.

PubMed

Huang, Boshi; Wang, Xueshun; Liu, Xinhao; Chen, Zihui; Li, Wanzhuo; Sun, Songkai; Liu, Huiqing; Daelemans, Dirk; De Clercq, Erik; Pannecouque, Christophe; Zhan, Peng; Liu, Xinyong

2017-08-15

Crystallographic overlap studies and pharmacophoric analysis indicated that diarylpyrimidine (DAPY)-based HIV-1 NNRTIs showed a similar binding mode and pharmacophoric features as indolylarylsulfones (IASs), another class of potent NNRTIs. Thus, a novel series of DAPY-IAS hybrid derivatives were identified as newer NNRTIs using structure-based molecular hybridization. Some target compounds exhibited moderate activities against HIV-1 IIIB strain, among which the two most potent inhibitors possessed EC 50 values of 1.48μM and 1.61μM, respectively. They were much potent than the reference drug ddI (EC 50 =76.0μM) and comparable to 3TC (EC 50 =2.54μM). Compound 7a also exhibited the favorable selectivity index (SI=80). Preliminary structure-activity relationships (SARs), structure-cytotoxicity relationships, molecular modeling studies, and in silico calculation of physicochemical properties of these new inhibitors were also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Discovery of sodium R-(+)-4-{2-[5-(2-fluoro-3-methoxyphenyl)-3-(2-fluoro-6-[trifluoromethyl]benzyl)-4-methyl-2,6-dioxo-3,6-dihydro-2H-pyrimidin-1-yl]-1-phenylethylamino}butyrate (elagolix), a potent and orally available nonpeptide antagonist of the human gonadotropin-releasing hormone receptor.

PubMed

Chen, Chen; Wu, Dongpei; Guo, Zhiqiang; Xie, Qiu; Reinhart, Greg J; Madan, Ajay; Wen, Jenny; Chen, Takung; Huang, Charles Q; Chen, Mi; Chen, Yongsheng; Tucci, Fabio C; Rowbottom, Martin; Pontillo, Joseph; Zhu, Yun-Fei; Wade, Warren; Saunders, John; Bozigian, Haig; Struthers, R Scott

2008-12-11

The discovery of novel uracil phenylethylamines bearing a butyric acid as potent human gonadotropin-releasing hormone receptor (hGnRH-R) antagonists is described. A major focus of this optimization was to improve the CYP3A4 inhibition liability of these uracils while maintaining their GnRH-R potency. R-4-{2-[5-(2-fluoro-3-methoxyphenyl)-3-(2-fluoro-6-[trifluoromethyl]benzyl)-4-methyl-2,6-dioxo-3,6-dihydro-2H-pyrimidin-1-yl]-1-phenylethylamino}butyric acid sodium salt, 10b (elagolix), was identified as a potent and selective hGnRH-R antagonist. Oral administration of 10b suppressed luteinizing hormone in castrated macaques. These efforts led to the identification of 10b as a clinical compound for the treatment of endometriosis.

Expanding the Bioactive Chemical Space of Anthrabenzoxocinones through Engineering the Highly Promiscuous Biosynthetic Modification Steps.

PubMed

Mei, Xianyi; Yan, Xiaoli; Zhang, Hui; Yu, Mingjia; Shen, Guangqing; Zhou, Linjun; Deng, Zixin; Lei, Chun; Qu, Xudong

2018-01-19

Anthrabenzoxocinones (ABXs) including (-)-ABXs and (+)-ABXs are a group of bacterial FabF-specific inhibitors with potent antimicrobial activity of resistant strains. Optimization of their chemical structures is a promising method to develop potent antibiotics. Through biosynthetic investigation, we herein identified and characterized two highly promiscuous enzymes involved in the (-)-ABX structural modification. The promiscuous halogenase and methyltransferase can respectively introduce halogen-modifications into various positions of the ABX scaffolds and methylation to highly diverse substrates. Manipulation of their activity in both of the (-)-ABXs and (+)-ABXs biosyntheses led to the generation of 14 novel ABX analogues of both enantiomers. Bioactivity assessment revealed that a few of the analogues showed significantly improved antimicrobial activity, with the C3-hydroxyl and chlorine substitutions critical for their activity. This study enormously expands the bioactive chemical space of the ABX family and FabF-specific inhibitors. The disclosed broad-selective biosynthetic machineries and structure-activity relationship provide a solid basis for further generation of potent antimicrobial agents.

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.

The bifunctional μ opioid agonist/antioxidant [Dmt(1)]DALDA is a superior analgesic in an animal model of complex regional pain syndrome-type i.

PubMed

Schiller, Peter W; Nguyen, Thi M-D; Saray, Amy; Poon, Annie Wing Hoi; Laferrière, André; Coderre, Terence J

2015-11-18

Reactive oxygen species (ROS) play an important role in the development of complex regional pain syndrome-Type I (CRPS-I), as also demonstrated with the chronic post ischemia pain (CPIP) animal model of CRPS-I. We show that morphine and the antioxidant N-acetylcysteine (NAC) act synergistically to reduce mechanical allodynia in CPIP rats. The tetrapeptide amide [Dmt(1)]DALDA (H-Dmt-d-Arg-Phe-Lys-NH2) is a potent and selective μ opioid receptor (MOR) agonist with favorable pharmacokinetic properties and with antioxidant activity due to its N-terminal Dmt (2',6'-dimethyltyrosine) residue. In the CPIP model, [Dmt(1)]DALDA was 15-fold more potent than morphine in reversing mechanical allodynia and 4.5-fold more potent as analgesic in the heat algesia test. The results indicate that bifunctional compounds with MOR agonist/antioxidant activity have therapeutic potential for the treatment of CRPS-I.

Antimicrobial Activity and Mechanism of Inhibition of Silver Nanoparticles against Extreme Halophilic Archaea.

PubMed

Thombre, Rebecca S; Shinde, Vinaya; Thaiparambil, Elvina; Zende, Samruddhi; Mehta, Sourabh

2016-01-01

Haloarchaea are salt-loving halophilic microorganisms that inhabit marine environments, sea water, salterns, and lakes. The resistance of haloarchaea to physical extremities that challenge organismic survival is ubiquitous. Metal and antibiotic resistance of haloarchaea has been on an upsurge due to the exposure of these organisms to metal sinks and drug resistance genes augmented in their natural habitats due to anthropogenic activities and environmental pollution. The efficacy of silver nanoparticles (SNPs) as a potent and broad spectrum inhibitory agent is known, however, there are no reports on the inhibitory activity of SNPs against haloarchaea. In the present study, we have investigated the antimicrobial potentials of SNPs synthesized using aqueous leaf extract of Cinnamomum tamala against antibiotic resistant haloarchaeal isolates Haloferax prahovense RR8, Haloferax lucentense RR15, Haloarcula argentinensis RR10 and Haloarcula tradensis RR13. The synthesized SNPs were characterized by UV-Vis spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, dynamic light scattering, X-ray diffraction and Fourier transform infrared spectroscopy. The SNPs demonstrated potent antimicrobial activity against the haloarchaea with a minimum inhibitory concentration of 300-400 μg/ml. Growth kinetics of haloarchaea in the presence of SNPs was studied by employing the Baranyi mathematical model for microbial growth using the DMFit curve fitting program. The C. tamala SNPs also demonstrated cytotoxic activity against human lung adenocarcinoma epithelial cell line (A540) and human breast adenocarcinoma cell line (MCF-7). The mechanism of inhibition of haloarchaea by the SNPs was investigated. The plausible mechanism proposed is the alterations and disruption of haloarchaeal membrane permeability by turbulence, inhibition of respiratory dehydrogenases and lipid peroxidation causing cellular and DNA damage resulting in cell death.

Winter storms drive rapid phenotypic, regulatory, and genomic shifts in the green anole lizard.

PubMed

Campbell-Staton, Shane C; Cheviron, Zachary A; Rochette, Nicholas; Catchen, Julian; Losos, Jonathan B; Edwards, Scott V

2017-08-04

Extreme environmental perturbations offer opportunities to observe the effects of natural selection in wild populations. During the winter of 2013-2014, the southeastern United States endured an extreme cold event. We used thermal performance, transcriptomics, and genome scans to measure responses of lizard populations to storm-induced selection. We found significant increases in cold tolerance at the species' southern limit. Gene expression in southern survivors shifted toward patterns characteristic of northern populations. Comparing samples before and after the extreme winter, 14 genomic regions were differentiated in the surviving southern population; four also exhibited signatures of local adaptation across the latitudinal gradient and implicate genes involved in nervous system function. Together, our results suggest that extreme winter events can rapidly produce strong selection on natural populations at multiple biological levels that recapitulate geographic patterns of local adaptation. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Mitotic Checkpoint Kinase Mps1 Has a Role in Normal Physiology which Impacts Clinical Utility

PubMed Central

Martinez, Ricardo; Blasina, Alessandra; Hallin, Jill F.; Hu, Wenyue; Rymer, Isha; Fan, Jeffery; Hoffman, Robert L.; Murphy, Sean; Marx, Matthew; Yanochko, Gina; Trajkovic, Dusko; Dinh, Dac; Timofeevski, Sergei; Zhu, Zhou; Sun, Peiquing; Lappin, Patrick B.; Murray, Brion W.

2015-01-01

Cell cycle checkpoint intervention is an effective therapeutic strategy for cancer when applied to patients predisposed to respond and the treatment is well-tolerated. A critical cell cycle process that could be targeted is the mitotic checkpoint (spindle assembly checkpoint) which governs the metaphase-to-anaphase transition and insures proper chromosomal segregation. The mitotic checkpoint kinase Mps1 was selected to explore whether enhancement in genomic instability is a viable therapeutic strategy. The basal-a subset of triple-negative breast cancer was chosen as a model system because it has a higher incidence of chromosomal instability and Mps1 expression is up-regulated. Depletion of Mps1 reduces tumor cell viability relative to normal cells. Highly selective, extremely potent Mps1 kinase inhibitors were created to investigate the roles of Mps1 catalytic activity in tumor cells and normal physiology (PF-7006, PF-3837; K i<0.5 nM; cellular IC50 2–6 nM). Treatment of tumor cells in vitro with PF-7006 modulates expected Mps1-dependent biology as demonstrated by molecular and phenotypic measures (reduced pHH3-Ser10 levels, shorter duration of mitosis, micro-nucleation, and apoptosis). Tumor-bearing mice treated with PF-7006 exhibit tumor growth inhibition concomitant with pharmacodynamic modulation of a downstream biomarker (pHH3-Ser10). Unfortunately, efficacy only occurs at drug exposures that cause dose-limiting body weight loss, gastrointestinal toxicities, and neutropenia. Mps1 inhibitor toxicities may be mitigated by inducing G1 cell cycle arrest in Rb1-competent cells with the cyclin-dependent kinase-4/6 inhibitor palbociclib. Using an isogenic cellular model system, PF-7006 is shown to be selectively cytotoxic to Rb1-deficient cells relative to Rb1-competent cells (also a measure of kinase selectivity). Human bone marrow cells pretreated with palbociclib have decreased PF-7006-dependent apoptosis relative to cells without palbociclib pretreatment. Collectively, this study raises a concern that single agent therapies inhibiting Mps1 will not be well-tolerated clinically but may be when combined with a selective CDK4/6 drug. PMID:26398286

Mitotic Checkpoint Kinase Mps1 Has a Role in Normal Physiology which Impacts Clinical Utility.

PubMed

Martinez, Ricardo; Blasina, Alessandra; Hallin, Jill F; Hu, Wenyue; Rymer, Isha; Fan, Jeffery; Hoffman, Robert L; Murphy, Sean; Marx, Matthew; Yanochko, Gina; Trajkovic, Dusko; Dinh, Dac; Timofeevski, Sergei; Zhu, Zhou; Sun, Peiquing; Lappin, Patrick B; Murray, Brion W

2015-01-01

Cell cycle checkpoint intervention is an effective therapeutic strategy for cancer when applied to patients predisposed to respond and the treatment is well-tolerated. A critical cell cycle process that could be targeted is the mitotic checkpoint (spindle assembly checkpoint) which governs the metaphase-to-anaphase transition and insures proper chromosomal segregation. The mitotic checkpoint kinase Mps1 was selected to explore whether enhancement in genomic instability is a viable therapeutic strategy. The basal-a subset of triple-negative breast cancer was chosen as a model system because it has a higher incidence of chromosomal instability and Mps1 expression is up-regulated. Depletion of Mps1 reduces tumor cell viability relative to normal cells. Highly selective, extremely potent Mps1 kinase inhibitors were created to investigate the roles of Mps1 catalytic activity in tumor cells and normal physiology (PF-7006, PF-3837; Ki<0.5 nM; cellular IC50 2-6 nM). Treatment of tumor cells in vitro with PF-7006 modulates expected Mps1-dependent biology as demonstrated by molecular and phenotypic measures (reduced pHH3-Ser10 levels, shorter duration of mitosis, micro-nucleation, and apoptosis). Tumor-bearing mice treated with PF-7006 exhibit tumor growth inhibition concomitant with pharmacodynamic modulation of a downstream biomarker (pHH3-Ser10). Unfortunately, efficacy only occurs at drug exposures that cause dose-limiting body weight loss, gastrointestinal toxicities, and neutropenia. Mps1 inhibitor toxicities may be mitigated by inducing G1 cell cycle arrest in Rb1-competent cells with the cyclin-dependent kinase-4/6 inhibitor palbociclib. Using an isogenic cellular model system, PF-7006 is shown to be selectively cytotoxic to Rb1-deficient cells relative to Rb1-competent cells (also a measure of kinase selectivity). Human bone marrow cells pretreated with palbociclib have decreased PF-7006-dependent apoptosis relative to cells without palbociclib pretreatment. Collectively, this study raises a concern that single agent therapies inhibiting Mps1 will not be well-tolerated clinically but may be when combined with a selective CDK4/6 drug.

Hospitals and plastics. Dioxin prevention and medical waste incinerators.

PubMed

Thornton, J; McCally, M; Orris, P; Weinberg, J

1996-01-01

CHLORINATED DIOXINS and related compounds are extremely potent toxic substances, producing effects in humans and animals at extremely low doses. Because these compounds are persistent in the environment and accumulate in the food chain, they are now distributed globally, and every member of the human population is exposed to them, primarily through the food supply and mothers' milk. An emerging body of information suggests that dioxin contamination has reached a level that may pose a large-scale, long-term public health risk. Of particular concern are dioxin's effects on reproduction, development, immune system function, and carcinogenesis. Medical waste incineration is a major source of dioxins. Polyvinyl chloride (PVC) plastic, as the dominant source of organically bound chlorine in the medical waste stream, is the primary cause of "iatrogenic" dioxin produced by the incineration of medical wastes. Health professionals have a responsibility to work to reduce dioxin exposure from medical sources. Health care institutions should implement policies to reduce the use of PVC plastics, thus achieving major reductions in medically related dioxin formation.

Design, synthesis and activity of BBI608 derivatives targeting on stem cells.

PubMed

Zhou, Qifan; Peng, Chen; Du, Fangyu; Zhou, Linbo; Shi, Yajie; Du, Yang; Liu, Dongdong; Sun, Wenjiao; Zhang, Meixia; Chen, Guoliang

2018-05-10

STAT3 plays a vital role in maintaining the self-renewal of tumor stem cells. BBI608, a small molecule identified by its ability to inhibit gene transcription driven by STAT3 and cancer stemness properties, can inhibit stemness gene expression and kill stemness-high cancer cells isolated from a variety of cancer types. In order to improve the pharmacokinetic properties of BBI608 and the antitumor activity, a series of BBI608 derivatives were designed and synthesized here. Most of these compounds were more potent than BBI608 on HepG2 cells, compound LD-8 had the most potent inhibitory activity among them and was 5.4-fold more potent than BBI608 (IC 50  = 11.2 μM), but had considerable activity on normal liver cells L-02. Compounds LD-17 (IC 50  = 3.5 μM) and LD-19 (IC 50  = 2.9 μM) were found to possess significant inhibitory activities and good selectivity. The results showed that compound LD-19 was worthy to investigate further as a lead compound according to its potent inhibitory activity, ideal ClogP value and better water solubility. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Turning a Substrate Peptide into a Potent Inhibitor for the Histone Methyltransferase SETD8

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

Judge, Russell A.; Zhu, Haizhong; Upadhyay, Anup K.

SETD8 is a histone H4–K20 methyltransferase that plays an essential role in the maintenance of genomic integrity during mitosis and in DNA damage repair, making it an intriguing target for cancer research. While some small molecule inhibitors for SETD8 have been reported, the structural binding modes for these inhibitors have not been revealed. Using the complex structure of the substrate peptide bound to SETD8 as a starting point, different natural and unnatural amino acid substitutions were tested, and a potent (Ki 50 nM, IC50 0.33 μM) and selective norleucine containing peptide inhibitor has been obtained.

5-Substituted 3-chlorokenpaullone derivatives are potent inhibitors of Trypanosoma brucei bloodstream forms.

PubMed

Orban, Oliver C F; Korn, Ricarda S; Benítez, Diego; Medeiros, Andrea; Preu, Lutz; Loaëc, Nadège; Meijer, Laurent; Koch, Oliver; Comini, Marcelo A; Kunick, Conrad

2016-08-15

Trypanothione synthetase is an essential enzyme for kinetoplastid parasites which cause highly disabling and fatal diseases in humans and animals. Inspired by the observation that N(5)-substituted paullones inhibit the trypanothione synthetase from the related parasite Leishmania infantum, we designed and synthesized a series of new derivatives. Although none of the new compounds displayed strong inhibition of Trypanosoma brucei trypanothione synthetase, several of them caused a remarkable growth inhibition of cultivated Trypanosoma brucei bloodstream forms. The most potent congener 3a showed antitrypanosomal activity in double digit nanomolar concentrations and a selectivity index of three orders of magnitude versus murine macrophage cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selective blockade of TRPA1 channel attenuates pathological pain without altering noxious cold sensation or body temperature regulation.

PubMed

Chen, Jun; Joshi, Shailen K; DiDomenico, Stanley; Perner, Richard J; Mikusa, Joe P; Gauvin, Donna M; Segreti, Jason A; Han, Ping; Zhang, Xu-Feng; Niforatos, Wende; Bianchi, Bruce R; Baker, Scott J; Zhong, Chengmin; Simler, Gricelda H; McDonald, Heath A; Schmidt, Robert G; McGaraughty, Steve P; Chu, Katharine L; Faltynek, Connie R; Kort, Michael E; Reilly, Regina M; Kym, Philip R

2011-05-01

Despite the increasing interest in TRPA1 channel as a pain target, its role in cold sensation and body temperature regulation is not clear; the efficacy and particularly side effects resulting from channel blockade remain poorly understood. Here we use a potent, selective, and bioavailable antagonist to address these issues. A-967079 potently blocks human (IC(50): 51 nmol/L, electrophysiology, 67 nmol/L, Ca(2+) assay) and rat TRPA1 (IC(50): 101 nmol/L, electrophysiology, 289 nmol/L, Ca(2+) assay). It is >1000-fold selective over other TRP channels, and is >150-fold selective over 75 other ion channels, enzymes, and G-protein-coupled receptors. Oral dosing of A-967079 produces robust drug exposure in rodents, and exhibits analgesic efficacy in allyl isothiocyanate-induced nocifensive response and osteoarthritic pain in rats (ED(50): 23.2 mg/kg, p.o.). A-967079 attenuates cold allodynia produced by nerve injury but does not alter noxious cold sensation in naive animals, suggesting distinct roles of TRPA1 in physiological and pathological states. Unlike TRPV1 antagonists, A-967079 does not alter body temperature. It also does not produce locomotor or cardiovascular side effects. Collectively, these data provide novel insights into TRPA1 function and suggest that the selective TRPA1 blockade may present a viable strategy for alleviating pain without untoward side effects. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

NASA Astrophysics Data System (ADS)

Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

2016-06-01

Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2‧,3‧,4‧,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2‧,3‧,4‧-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15-45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme.

Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

PubMed Central

Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

2016-01-01

Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2′,3′,4′,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2′,3′,4′-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15–45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme. PMID:27263468

Mastering tricyclic ring systems for desirable functional cannabinoid activity

PubMed Central

Petrov, Ravil R.; Knight, Lindsay; Chen, Shao-Rui; Wager-Miller, Jim; McDaniel, Steven W.; Diaz, Fanny; Barth, Francis; Pan, Hui-Lin; Mackie, Ken; Cavasotto, Claudio N.; Diaz, Philippe

2013-01-01

There is growing interest in using cannabinoid receptor 2 (CB2) agonists for the treatment of neuropathic pain and other indications. In continuation of our ongoing program aiming for the development of new small molecule cannabinoid ligands, we have synthesized a novel series of carbazole and γ-carboline derivatives. The affinities of the newly synthesized compounds were determined by a competitive radioligand displacement assay for human CB2 cannabinoid receptor and rat CB1 cannabinoid receptor. Functional activity and selectivity at human CB1 and CB2 receptors were characterized using receptor internalization and [35S]GTP-γ-S assays. The structure-activity relationship and optimization studies of the carbazole series have led to the discovery of a non-selective CB1 and CB2 agonist, compound 4. Our subsequent research efforts to increase CB2 selectivity of this lead compound have led to the discovery of CB2 selective compound 64, which robustly internalized CB2 receptors. Compound 64 had potent inhibitory effects on pain hypersensitivity in a rat model of neuropathic pain. Other potent and CB2 receptor–selective compounds, including compounds 63 and 68, and a selective CB1 agonist, compound 74 were also discovered. In addition, we identified the CB2 ligand 35 which failed to promote CB2 receptor internalization and inhibited compound CP55,940-induced CB2 internalization despite a high CB2 receptor affinity. The present study provides novel tricyclic series as a starting point for further investigations of CB2 pharmacology and pain treatment. PMID:24125850

Highly Constrained Bicyclic Scaffolds for the Discovery of Protease-Stable Peptides via mRNA Display.

PubMed

Hacker, David E; Hoinka, Jan; Iqbal, Emil S; Przytycka, Teresa M; Hartman, Matthew C T

2017-03-17

Highly constrained peptides such as the knotted peptide natural products are promising medicinal agents because of their impressive biostability and potent activity. Yet, libraries of highly constrained peptides are challenging to prepare. Here, we present a method which utilizes two robust, orthogonal chemical steps to create highly constrained bicyclic peptide libraries. This technology was optimized to be compatible with in vitro selections by mRNA display. We performed side-by-side monocyclic and bicyclic selections against a model protein (streptavidin). Both selections resulted in peptides with mid-nanomolar affinity, and the bicyclic selection yielded a peptide with remarkable protease resistance.

CLONAL EVOLUTION IN CANCER

PubMed Central

Greaves, Mel; Maley, Carlo C.

2012-01-01

Cancers evolve by a reiterative process of clonal expansion, genetic diversification and clonal selection within the adaptive landscapes of tissue ecosystems. The dynamics are complex with highly variable patterns of genetic diversity and resultant clonal architecture. Therapeutic intervention may decimate cancer clones, and erode their habitats, but inadvertently provides potent selective pressure for the expansion of resistant variants. The inherently Darwinian character of cancer lies at the heart of therapeutic failure but perhaps also holds the key to more effective control. PMID:22258609

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.

Heterogeneity of NK-2 tachykinin receptors in hamster and rabbit smooth muscles.

PubMed

Maggi, C A; Eglezos, A; Quartara, L; Patacchini, R; Giachetti, A

1992-01-23

The possible existence of NK-2 receptor subtypes in peripheral smooth muscle preparations from rabbit and hamster was investigated by studying the effect of neurokinin A, the selective NK-2 receptor agonist [beta Ala8] neurokinin A (4-10), the selective NK-2 tachykinin receptor antagonists, MEN 10,376, L 659,877 and R 396, and the pseudopeptide derivative of neurokinin A (4-10), MDL 28,564. All experiments were performed in the presence of peptidase inhibitors (captopril, bestatin and thiorphan, 1 microM each). Both neurokinin A and [beta Ala8] neurokinin A (4-10) produced concentration-dependent contractions of the rabbit isolated bronchus and hamster isolated stomach and colon, as well as enhancement of the nerve-mediated twitches of rabbit isolated vas deferens (pars prostatica). MEN 10,376, L 659,877 and R 396 antagonized the effect of the NK-2 receptor selective agonist in all four tissues under study, although marked differences in antagonist potency were evident for the three antagonists. Thus MEN 10,376 was distinctly more potent (about 100 times) in rabbit than in hamster preparations while L 659,877 and R 396 were more potent in hamster than rabbit preparations. MDL 28,564 showed a distinct agonist character in rabbit preparations while it was virtually inactive in hamster preparations, where it antagonized the effect of the NK-2 receptor selective agonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of 2',6'-dimethyl-l-tyrosine (Dmt) in some opioid lead compounds.

PubMed

Balboni, Gianfranco; Marzola, Erika; Sasaki, Yusuke; Ambo, Akihiro; Marczak, Ewa D; Lazarus, Lawrence H; Salvadori, Severo

2010-08-15

Here we evaluated how the interchange of the amino acids 2',6'-dimethyl-L-tyrosine (Dmt), 2',6'-difluoro-L-tyrosine (Dft), and tyrosine in position 1 can affect the pharmacological characterization of some reference opioid peptides and pseudopeptides. Generally, Dft and Tyr provide analogues with a similar pharmacological profile, despite different pK(a) values. Dmt/Tyr(Dft) replacement gives activity changes depending on the reference opioid in which the modification was made. Whereas, H-Dmt-Tic-Asp *-Bid is a potent and selective delta agonist (MVD, IC(50)=0.12nM); H-Dft-Tic-Asp *-Bid and H-Tyr-Tic-Asp *-Bid are potent and selective delta antagonists (pA(2)=8.95 and 8.85, respectively). When these amino acids are employed in the synthesis of deltorphin B and its Dmt(1) and Dft(1) analogues, the three compounds maintain a very similar delta agonism (MVD, IC(50) 0.32-0.53 nM) with a decrease in selectivity relative to the Dmt(1) analogue. In the less selective H-Dmt-Tic-Gly *-Bid the replacement of Dmt with Dft and Tyr retains the delta agonism but with a decrease in potency. Antagonists containing the Dmt-Tic pharmacophore do not support the exchange of Dmt with Dft or Tyr. Copyright 2010 Elsevier Ltd. All rights reserved.

Spoken language identification based on the enhanced self-adjusting extreme learning machine approach.

PubMed

Albadr, Musatafa Abbas Abbood; Tiun, Sabrina; Al-Dhief, Fahad Taha; Sammour, Mahmoud A M

2018-01-01

Spoken Language Identification (LID) is the process of determining and classifying natural language from a given content and dataset. Typically, data must be processed to extract useful features to perform LID. The extracting features for LID, based on literature, is a mature process where the standard features for LID have already been developed using Mel-Frequency Cepstral Coefficients (MFCC), Shifted Delta Cepstral (SDC), the Gaussian Mixture Model (GMM) and ending with the i-vector based framework. However, the process of learning based on extract features remains to be improved (i.e. optimised) to capture all embedded knowledge on the extracted features. The Extreme Learning Machine (ELM) is an effective learning model used to perform classification and regression analysis and is extremely useful to train a single hidden layer neural network. Nevertheless, the learning process of this model is not entirely effective (i.e. optimised) due to the random selection of weights within the input hidden layer. In this study, the ELM is selected as a learning model for LID based on standard feature extraction. One of the optimisation approaches of ELM, the Self-Adjusting Extreme Learning Machine (SA-ELM) is selected as the benchmark and improved by altering the selection phase of the optimisation process. The selection process is performed incorporating both the Split-Ratio and K-Tournament methods, the improved SA-ELM is named Enhanced Self-Adjusting Extreme Learning Machine (ESA-ELM). The results are generated based on LID with the datasets created from eight different languages. The results of the study showed excellent superiority relating to the performance of the Enhanced Self-Adjusting Extreme Learning Machine LID (ESA-ELM LID) compared with the SA-ELM LID, with ESA-ELM LID achieving an accuracy of 96.25%, as compared to the accuracy of SA-ELM LID of only 95.00%.

Spoken language identification based on the enhanced self-adjusting extreme learning machine approach

PubMed Central

Tiun, Sabrina; AL-Dhief, Fahad Taha; Sammour, Mahmoud A. M.

2018-01-01

Spoken Language Identification (LID) is the process of determining and classifying natural language from a given content and dataset. Typically, data must be processed to extract useful features to perform LID. The extracting features for LID, based on literature, is a mature process where the standard features for LID have already been developed using Mel-Frequency Cepstral Coefficients (MFCC), Shifted Delta Cepstral (SDC), the Gaussian Mixture Model (GMM) and ending with the i-vector based framework. However, the process of learning based on extract features remains to be improved (i.e. optimised) to capture all embedded knowledge on the extracted features. The Extreme Learning Machine (ELM) is an effective learning model used to perform classification and regression analysis and is extremely useful to train a single hidden layer neural network. Nevertheless, the learning process of this model is not entirely effective (i.e. optimised) due to the random selection of weights within the input hidden layer. In this study, the ELM is selected as a learning model for LID based on standard feature extraction. One of the optimisation approaches of ELM, the Self-Adjusting Extreme Learning Machine (SA-ELM) is selected as the benchmark and improved by altering the selection phase of the optimisation process. The selection process is performed incorporating both the Split-Ratio and K-Tournament methods, the improved SA-ELM is named Enhanced Self-Adjusting Extreme Learning Machine (ESA-ELM). The results are generated based on LID with the datasets created from eight different languages. The results of the study showed excellent superiority relating to the performance of the Enhanced Self-Adjusting Extreme Learning Machine LID (ESA-ELM LID) compared with the SA-ELM LID, with ESA-ELM LID achieving an accuracy of 96.25%, as compared to the accuracy of SA-ELM LID of only 95.00%. PMID:29672546

The Rise and Fall of an Evolutionary Innovation: Contrasting Strategies of Venom Evolution in Ancient and Young Animals

PubMed Central

Sunagar, Kartik; Moran, Yehu

2015-01-01

Animal venoms are theorized to evolve under the significant influence of positive Darwinian selection in a chemical arms race scenario, where the evolution of venom resistance in prey and the invention of potent venom in the secreting animal exert reciprocal selection pressures. Venom research to date has mainly focused on evolutionarily younger lineages, such as snakes and cone snails, while mostly neglecting ancient clades (e.g., cnidarians, coleoids, spiders and centipedes). By examining genome, venom-gland transcriptome and sequences from the public repositories, we report the molecular evolutionary regimes of several centipede and spider toxin families, which surprisingly accumulated low-levels of sequence variations, despite their long evolutionary histories. Molecular evolutionary assessment of over 3500 nucleotide sequences from 85 toxin families spanning the breadth of the animal kingdom has unraveled a contrasting evolutionary strategy employed by ancient and evolutionarily young clades. We show that the venoms of ancient lineages remarkably evolve under the heavy constraints of negative selection, while toxin families in lineages that originated relatively recently rapidly diversify under the influence of positive selection. We propose that animal venoms mostly employ a ‘two-speed’ mode of evolution, where the major influence of diversifying selection accompanies the earlier stages of ecological specialization (e.g., diet and range expansion) in the evolutionary history of the species–the period of expansion, resulting in the rapid diversification of the venom arsenal, followed by longer periods of purifying selection that preserve the potent toxin pharmacopeia–the period of purification and fixation. However, species in the period of purification may re-enter the period of expansion upon experiencing a major shift in ecology or environment. Thus, we highlight for the first time the significant roles of purifying and episodic selections in shaping animal venoms. PMID:26492532

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

Inhibitory effects of Agaricus blazei extracts on human myeloid leukemia cells.

PubMed

Kim, Chi-Fai; Jiang, Jing-Jing; Leung, Kwok-Nam; Fung, Kwok-Pui; Lau, Clara Bik-San

2009-03-18

Agaricus blazei has been used as an adjuvant in cancer chemotherapy and is found to inhibit the growth of various types of tumor cells. Our study has adopted a systematic and bioassay-guided approach to optimize the extraction of Agaricus blazei for anti-leukemic bioactive components. The tumor-selective growth inhibitory activity of the extracts on leukemic cell lines was evaluated in vitro and in vivo using tumor-bearing nude mice. Agaricus blazei extracts were prepared using different methods. MTT and tritiated thymidine incorporation assays were used to evaluate the in vitro anti-leukemic effects. The most potent extract was further investigated using NB-4 cells-bearing nude mice and mechanistic studies using DNA fragmentation assay and cell death detection ELISA. The JAB80E70 extract showed the most potent tumor-selective growth inhibitory activity against human leukemia NB-4 and K-562 cells. This is the first report of anti-leukemic activity of JAB80E70 in athymic nude mice bearing NB-4 cells. Using DNA fragmentation assays and cell death detection ELISA, JAB80E70 was found to induce apoptosis in NB-4 cells. However, the polysaccharide enriched fractions failed to show significant cytotoxicity on NB-4 cells in vitro. The JAB80E70 extract exhibited potent anti-leukemic effect in vitro and in vivo. The effect can be attributed, at least in part, to the induction of apoptosis. Besides, polysaccharides in Agaricus blazei may not possess direct anti-leukemic activity in vitro.

Nanobodies that block gating of the P2X7 ion channel ameliorate inflammation.

PubMed

Danquah, Welbeck; Meyer-Schwesinger, Catherine; Rissiek, Björn; Pinto, Carolina; Serracant-Prat, Arnau; Amadi, Miriam; Iacenda, Domenica; Knop, Jan-Hendrik; Hammel, Anna; Bergmann, Philine; Schwarz, Nicole; Assunção, Joana; Rotthier, Wendy; Haag, Friedrich; Tolosa, Eva; Bannas, Peter; Boué-Grabot, Eric; Magnus, Tim; Laeremans, Toon; Stortelers, Catelijne; Koch-Nolte, Friedrich

2016-11-23

Ion channels are desirable therapeutic targets, yet ion channel-directed drugs with high selectivity and few side effects are still needed. Unlike small-molecule inhibitors, antibodies are highly selective for target antigens but mostly fail to antagonize ion channel functions. Nanobodies-small, single-domain antibody fragments-may overcome these problems. P2X7 is a ligand-gated ion channel that, upon sensing adenosine 5'-triphosphate released by damaged cells, initiates a proinflammatory signaling cascade, including release of cytokines, such as interleukin-1β (IL-1β). To further explore its function, we generated and characterized nanobodies against mouse P2X7 that effectively blocked (13A7) or potentiated (14D5) gating of the channel. Systemic injection of nanobody 13A7 in mice blocked P2X7 on T cells and macrophages in vivo and ameliorated experimental glomerulonephritis and allergic contact dermatitis. We also generated nanobody Dano1, which specifically inhibited human P2X7. In endotoxin-treated human blood, Dano1 was 1000 times more potent in preventing IL-1β release than small-molecule P2X7 antagonists currently in clinical development. Our results show that nanobody technology can generate potent, specific therapeutics against ion channels, confirm P2X7 as a therapeutic target for inflammatory disorders, and characterize a potent new drug candidate that targets P2X7. Copyright © 2016, American Association for the Advancement of Science.

Potent inhibition of monoamine oxidase A by decursin from Angelica gigas Nakai and by wogonin from Scutellaria baicalensis Georgi.

PubMed

Lee, Hyun Woo; Ryu, Hyung Won; Kang, Myung-Gyun; Park, Daeui; Lee, Hanna; Shin, Heung Mook; Oh, Sei-Ryang; Kim, Hoon

2017-04-01

During the ongoing search for new monoamine oxidase (MAO) inhibitors, five coumarin derivatives and eight flavonoids were isolated from the roots of Angelica gigas Nakai and Scutellaria baicalensis Georgi, respectively. Of the phytochemicals, decursin (4) was found to potently and selectively inhibit human MAO-A (IC 50 =1.89μM). The IC 50 value of 4 for MAO-A belonged to the lowest group in herbal sources and was similar to that of toloxatone (1.78μM), a marketed drug. Wogonin (11) effectively inhibited MAO-A and MAO-B (IC 50 =6.35 and 20.8μM, respectively). Furthermore, compounds 5 (decursinol angelate) and 10 (baicalein) were observed to selectively and moderately inhibit MAO-A. In addition, compound 4 reversibly and competitively inhibited MAO-A with a K i of 0.17μM. Compound 11 also competitively inhibited MAO-A and MAO-B (K i =0.56 and 1.96μM, respectively). Molecular docking simulation revealed that 4 interacts with Asn181 residue of MAO-A or Asn116 residue of MAO-B by formation of hydrogen bond. The findings suggest compounds 4 and 11 be considered as new potent and reversible MAO-A inhibitors or useful lead compounds for the developments of MAO inhibitors for the treatment of disorders like depression, Parkinson's disease and Alzheimer disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Interrogating alkyl and arylalkylpolyamino (bis)urea and (bis)thiourea isosteres as potent antimalarial chemotypes against multiple lifecycle forms of Plasmodium falciparum parasites.

PubMed

Verlinden, Bianca K; de Beer, Marna; Pachaiyappan, Boobalan; Besaans, Ethan; Andayi, Warren A; Reader, Janette; Niemand, Jandeli; van Biljon, Riette; Guy, Kiplin; Egan, Timothy; Woster, Patrick M; Birkholtz, Lyn-Marie

2015-08-15

A new series of potent potent aryl/alkylated (bis)urea- and (bis)thiourea polyamine analogues were synthesized and evaluated in vitro for their antiplasmodial activity. Altering the carbon backbone and terminal substituents increased the potency of analogues in the compound library 3-fold, with the most active compounds, 15 and 16, showing half-maximal inhibitory concentrations (IC50 values) of 28 and 30 nM, respectively, against various Plasmodium falciparum parasite strains without any cross-resistance. In vitro evaluation of the cytotoxicity of these analogues revealed marked selectivity towards targeting malaria parasites compared to mammalian HepG2 cells (>5000-fold lower IC50 against the parasite). Preliminary biological evaluation of the polyamine analogue antiplasmodial phenotype revealed that (bis)urea compounds target parasite asexual proliferation, whereas (bis)thiourea compounds of the same series have the unique ability to block transmissible gametocyte forms of the parasite, indicating pluripharmacology against proliferative and non-proliferative forms of the parasite. In this manuscript, we describe these results and postulate a refined structure-activity relationship (SAR) model for antiplasmodial polyamine analogues. The terminally aryl/alkylated (bis)urea- and (bis)thiourea-polyamine analogues featuring a 3-5-3 or 3-6-3 carbon backbone represent a structurally novel and distinct class of potential antiplasmodials with activities in the low nanomolar range, and high selectivity against various lifecycle forms of P. falciparum parasites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Molecular mechanisms underlying the antitumor activity of (E)-N-hydroxy-3-(1-(4-methoxyphenylsulfonyl)-1,2,3,4-tetrahydroquinolin-6-yl)acrylamide in human colorectal cancer cells in vitro and in vivo

PubMed Central

Chen, Chun-Han; Lee, Chia-Hwa; Liou, Jing-Ping; Teng, Che-Ming; Pan, Shiow-Lin

2015-01-01

Upregulation of class I histone deacetylases (HDAC) correlates with poor prognosis in colorectal cancer (CRC) patients. Previous study revealed that (E)-N-hydroxy-3-(1-(4-methoxyphenylsulfonyl)-1,2,3,4-tetrahydroquinolin-6-yl)acrylamide (Compound 11) is a potent and selective class I HDAC inhibitor, exhibited significant anti-proliferative activity in various human cancer cell lines. In current study, we demonstrated that compound 11 exhibited significant anti-proliferative and cytotoxic activity in CRC cells. Notably, compound 11 was less potent than SAHA in inhibiting HDAC6 as evident from the lower expression of acetyl-α-tubulin, suggesting higher selectivity for class I HDACs. Mechanistically, compound 11 induced cell-cycle arrest at the G2/M phase, activated both intrinsic- and extrinsic-apoptotic pathways, altered the expression of Bcl-2 family proteins and exerted a potent inhibitory effect on survival signals (p-Akt, p-ERK) in CRC cells. Moreover, we provide evidence that compound 11 suppressed motility, decreased mesenchymal markers (N-cadherin and vimentin) and increased epithelial marker (E-cadherin) through down-regulation of Akt. The anti-tumor activity and underlying molecular mechanisms of compound 11 were further confirmed using the HCT116 xenograft model in vivo. Our findings provide evidence of the significant anti-tumor activity of compound 11 in a preclinical model, supporting its potential as a novel therapeutic agent for CRC. PMID:26462017

Clinical Drug-Drug Interactions Through Cytochrome P450 3A (CYP3A) for the Selective ALK Inhibitor Alectinib.

PubMed

Morcos, Peter N; Cleary, Yumi; Guerini, Elena; Dall, Georgina; Bogman, Katrijn; De Petris, Luigi; Viteri, Santiago; Bordogna, Walter; Yu, Li; Martin-Facklam, Meret; Phipps, Alex

2017-05-01

The efficacy and safety of alectinib, a central nervous system-active and selective anaplastic lymphoma kinase (ALK) inhibitor, has been demonstrated in patients with ALK-positive (ALK+) non-small cell lung cancer (NSCLC) progressing on crizotinib. Alectinib is mainly metabolized by cytochrome P450 3A (CYP3A) to a major similarly active metabolite, M4. Alectinib and M4 show evidence of weak time-dependent inhibition and small induction of CYP3A in vitro. We present results from 3 fixed-sequence studies evaluating drug-drug interactions for alectinib through CYP3A. Studies NP28990 and NP29042 enrolled 17 and 24 healthy subjects, respectively, and investigated potent CYP3A inhibition with posaconazole and potent CYP3A induction through rifampin, respectively, on the single oral dose pharmacokinetics (PK) of alectinib. A substudy of the global phase 2 NP28673 study enrolled 15 patients with ALK+ NSCLC to determine the effect of multiple doses of alectinib on the single oral dose PK of midazolam, a sensitive substrate of CYP3A. Potent CYP3A inhibition or induction resulted in only minor effects on the combined exposure of alectinib and M4. Multiple doses of alectinib did not influence midazolam exposure. These results suggest that dose adjustments may not be needed when alectinib is coadministered with CYP3A inhibitors or inducers or for coadministered CYP3A substrates. © 2016, The American College of Clinical Pharmacology.

Inhibition of Mutated Isocitrate Dehydrogenase 1 in Cancer.

PubMed

Wu, Fangrui; Cheng, Gang; Yao, Yuan; Kogiso, Mari; Jiang, Hong; Li, Xiao-Nan; Song, Yongcheng

2018-05-23

R132H mutation of isocitrate dehydrogenase 1 (IDH1) are found in ~75% of low-grade gliomas and secondary glioblastomas as well as in several other types of cancer. More chemotypes of inhibitors of IDH1(R132H) are therefore needed. To develop a new class of IDH1(R132H) inhibitors as potent antitumor agents. A biochemical assay was developed to find inhibitors of IDH1(R132H) mutant enzyme. Chemical synthesis and structure activity relationship studies were used to find compounds with improved potency. Antitumor activities of selected compounds were evaluated. A series of aromatic sulfonamide compounds were found to be novel, potent inhibitors of IDH1(R132H) with Ki values as low as 0.6 µM. Structure activity relationships of these compounds are discussed. Enzyme kinetics studies showed that one compound is a competitive inhibitor against the substrate α-KG and a non-competitive inhibitor against the cofactor NADPH. Several inhibitors were found to have no activity against wild-type IDH1, showing a high selectivity. Two potent inhibitors exhibited strong activity against proliferation of BT142 glioma cells with IDH1 R132H mutation, while these compounds did not significantly affect growth of glioma cells without IDH1 mutation. This novel series of IDH1(R132H) inhibitors have potential to be further developed for the treatment of glioma with IDH1 mutation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Fluorescein and Indocyanine Green Angiography for Uveitis

PubMed Central

Herbort, Carl P

2009-01-01

In recent years enormous progress has been achieved in investigational procedures for uveitis. Imaging is one such example with the advent of new methods such as indocyanine green angiography, ultrasound biomicroscopy and optical coherence tomography to cite only the most important. This tremendous increase in precision and accuracy in the assessment of the level and degree of inflammation and its monitoring comes in parallel with the development of extremely potent and efficacious therapies. In view of these developments, our whole attitude in the appraisal and investigation of the uveitis patient has to be adapted and correctly reoriented integrating the recent developments and this is no different for ocular angiography. PMID:20404985

[The recent research progress of chemistry of marine natural products].

PubMed

Shi, Qing-wen; Li, Li-geng; Wang, Yu-fang; Huo, Chang-hong; Zhang, Man-li

2010-10-01

Ocean is a unique and excellent resource that provides a diverse array of intriguing natural products. Marine natural products have demonstrated significant and extremely potent biological activities and have captured the attention of natural products chemists in the past few decades. It is increasingly recognized that a wealth of fascinating natural products and novel chemical entities will play a dominant role in the discovery of useful leads for the development of pharmaceutical agents and provide useful probes to lead to breakthroughs in a variety of life-science fields. This article focused on the research progress of chemistry of marine natural products in recent five years.

Progressive outer retinal necrosis after rituximab and cyclophosphamide therapy

PubMed Central

Dogra, Mohit; Bajgai, Priya; Kumar, Ashok; Sharma, Aman

2018-01-01

We report a case of progressive outer retinal necrosis (PORN) in a patient of microscopic polyangitis (MPA), being treated with immunosuppressive drugs such as cyclophosphamide and rituximab. Her aqueous tap was positive for Varicella Zoster virus and she was treated with oral and intravitreal antivirals, along with discontinuation of one of the immunosuppressive agents, i.e. rituximab, which might have led to reactivation of the virus causing necrotizing retinitis lesions. Rituximab and cyclophosphamide are extremely potent drugs, which are necessary to manage immunological disorders such as MPA. However, they may predispose the patient to serious complications like viral infections, including PORN. PMID:29582832

Lack of effect of tetrodotoxin and of an extract from the posterior salivary gland of the blue-ringed octopus following injection into the octopus and following application to its brachial nerve.

PubMed

Flachsenberger, W; Kerr, D I

1985-01-01

Lack of effect of tetrodotoxin and of an extract from the posterior salivary gland of the blue-ringed octopus following injection into the octopus and following application to its brachial nerve. Toxicon 23, 997-999, 1985. Injections of the blue-ringed octopus salivary gland extract and tetrodotoxin into the blue-ringed octopus have no ill-effect on the animals. Similarly, in vitro nerve preparations from the animal were not affected by these materials although they are both extremely potent on bioelectrically excitable preparations from other species.

How do extreme streamflow due to hurricane IRMA compare during 1938-2017 in South Eastern US?

NASA Astrophysics Data System (ADS)

Anandhi, A.

2017-12-01

The question related to Irma, Harvey, Maria, and other hurricanes is: are hurricane more frequent and intense than they have been in the past. Recent hurricanes were unusually strong hitting the US Coastline or territories as a category 4 or 5, dropping unusually large amounts of precipitation on the affected areas creating extreme high-flow events in rivers and streams in affected areas. The objective of the study is to determine how extreme are streamflows from recent hurricanes (e.g. IRMA) when compared to streamflow's during 1938-2017 time-period. Additionally, in this study, the extreme precipitations are also compared during IRMA. Extreme high flows are selected from Indicators of Hydrologic Alteration (IHA). They are distributions, timing, duration, frequency, magnitude, pulses, and days of extreme events in rivers of the southeastern United States and Gulf of Mexico Hydrologic Region—03. Streamflow data from 30 stations in the region with at least 79 years of record (1938-2017) are used. Historical precipitation changes is obtained from meta-analysis of published literature. Our preliminary results indicate the extremeness of streamflow from recent hurricanes vary with the IHA indicator selected. Some potential implications of these extreme events on the region's ecosystem are also discussed using causal chains and loops.

Extreme storm activity in North Atlantic and European region

NASA Astrophysics Data System (ADS)

Vyazilova, N.

2010-09-01

The extreme storm activity study over North Atlantic and Europe includes the analyses of extreme cyclone (track number, integral cyclonic intensity) and extreme storm (track number) during winter and summer seasons in the regions: 1) 55°N-80N, 50°W-70°E; 2) 30°N-55°N, 50°W-70°E. Extreme cyclones were selected based on cyclone centre pressure (P<=970 mbar). Extreme storms were selected from extreme cyclones based on wind velocity on 925 mbar. The Bofort scala was used for this goal. Integral cyclonic intensity (for region) includes the calculation cyclone centers number and sum of MSLP anomalies in cyclone centers. The analyses based on automated cyclone tracking algorithm, 6-hourly MSLP and wind data (u and v on 925 gPa) from the NCEP/NCAR reanalyses from January 1948 to March 2010. The comparision of mean, calculated for every ten years, had shown, that in polar region extreme cyclone and storm track number, and integral cyclonic intensity gradually increases and have maximum during last years (as for summer, as for winter season). Every ten years means for summer season are more then for winter season, as for polar, as for tropical region. Means (ten years) for tropical region are significance less then for polar region.

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 observations indicate that ER-119884 may also interfere with other cellular processes. PMID:18765694

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

Risk of mortality with concomitant use of tamoxifen and selective serotonin reuptake inhibitors: multi-database cohort study.

PubMed

Donneyong, Macarius M; Bykov, Katsiaryna; Bosco-Levy, Pauline; Dong, Yaa-Hui; Levin, Raisa; Gagne, Joshua J

2016-09-30

 To compare differences in mortality between women concomitantly treated with tamoxifen and selective serotonin reuptake inhibitors (SSRIs) that are potent inhibitors of the cytochrome-P450 2D6 enzyme (CYP2D6) versus tamoxifen and other SSRIs.  Population based cohort study.  Five US databases covering individuals enrolled in private and public health insurance programs from 1995 to 2013.  Two cohorts of women who started taking tamoxifen. In cohort 1, women started taking an SSRI during tamoxifen treatment. In cohort 2, women were already taking an SSRI when they started taking tamoxifen.  All cause mortality in each cohort in women taking SSRIs that are potent inhibitors of CYP2D6 (paroxetine, fluoxetine) versus other SSRIs. Propensity scores were used to match exposure groups in a variable ratio fashion. Results were measured separately for each cohort and combined hazard ratios calculated from Cox regression models across the two cohorts with random effects meta-analysis.  There were 6067 and 8465 new users of tamoxifen in cohorts 1 and 2, respectively. Mean age was 55. A total of 991 and 1014 deaths occurred in cohorts 1 and 2 during a median follow-up of 2.2 (interquartile range 0.9-4.5) and 2.0 (0.8-3.9) years, respectively. The pooled hazard ratio for death for potent inhibitors (rate 58.6/1000 person years) compared with other SSRIs (rate 57.9/1000 person years) across cohorts 1 and 2 was 0.96 (95% confidence interval 0.88 to 1.06). Results were consistent across sensitivity analyses.  Concomitant use of tamoxifen and potent CYP2D6 inhibiting SSRIs versus other SSRIs was not associated with an increased risk of death. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Phenotypic and genetic overlap between autistic traits at the extremes of the general population.

PubMed

Ronald, Angelica; Happé, Francesca; Price, Thomas S; Baron-Cohen, Simon; Plomin, Robert

2006-10-01

To investigate children selected from a community sample for showing extreme autistic-like traits and to assess the degree to which these individual traits--social impairments (SIs), communication impairments (CIs), and restricted repetitive behaviors and interests (RRBIs)--are caused by genes and environments, whether all of them are caused by the same genes and environments, and how often they occur together (as required by an autism diagnosis). The most extreme-scoring 5% were selected from 3,419 8-year-old pairs in the Twins Early Development Study assessed on the Childhood Asperger Syndrome Test. Phenotypic associations between extreme traits were compared with associations among the full-scale scores. Genetic associations between extreme traits were quantified using bivariate DeFries-Fulker extremes analysis. Phenotypic relationships between extreme SIs, CIs, and RRBIs were modest. There was a degree of genetic overlap between them, but also substantial genetic specificity. This first twin study assessing the links between extreme individual autistic-like traits (SIs, CIs, and RRBIs) found that all are highly heritable but show modest phenotypic and genetic overlap. This finding concurs with that of an earlier study from the same cohort that showed that a total autistic symptoms score at the extreme showed high heritability and that SIs, CIs, and RRBIs show weak links in the general population. This new finding has relevance for both clinical models and future molecular genetic studies.

Novel 2-aminotetralin and 3-aminochroman derivatives as selective serotonin 5-HT7 receptor agonists and antagonists.

PubMed

Holmberg, Pär; Sohn, Daniel; Leideborg, Robert; Caldirola, Patrizia; Zlatoidsky, Pavel; Hanson, Sverker; Mohell, Nina; Rosqvist, Susanne; Nordvall, Gunnar; Johansson, Anette M; Johansson, Rolf

2004-07-29

The understanding of the physiological role of the G-protein coupled serotonin 5-HT(7) receptor is largely rudimentary. Therefore, selective and potent pharmacological tools will add to the understanding of serotonergic effects mediated through this receptor. In this report, we describe two compound classes, chromans and tetralins, encompassing compounds with nanomolar affinity for the 5-HT(7) receptor and with good selectivity. Within theses classes, we have discovered both agonists and antagonists that can be used for further understanding of the pharmacology of the 5-HT(7) receptor.

Parallel medicinal chemistry approaches to selective HDAC1/HDAC2 inhibitor (SHI-1:2) optimization.

PubMed

Kattar, Solomon D; Surdi, Laura M; Zabierek, Anna; Methot, Joey L; Middleton, Richard E; Hughes, Bethany; Szewczak, Alexander A; Dahlberg, William K; Kral, Astrid M; Ozerova, Nicole; Fleming, Judith C; Wang, Hongmei; Secrist, Paul; Harsch, Andreas; Hamill, Julie E; Cruz, Jonathan C; Kenific, Candia M; Chenard, Melissa; Miller, Thomas A; Berk, Scott C; Tempest, Paul

2009-02-15

The successful application of both solid and solution phase library synthesis, combined with tight integration into the medicinal chemistry effort, resulted in the efficient optimization of a novel structural series of selective HDAC1/HDAC2 inhibitors by the MRL-Boston Parallel Medicinal Chemistry group. An initial lead from a small parallel library was found to be potent and selective in biochemical assays. Advanced compounds were the culmination of iterative library design and possess excellent biochemical and cellular potency, as well as acceptable PK and efficacy in animal models.

A compliant mechanism for inspecting extremely confined spaces

NASA Astrophysics Data System (ADS)

Mascareñas, David; Moreu, Fernando; Cantu, Precious; Shields, Daniel; Wadden, Jack; El Hadedy, Mohamed; Farrar, Charles

2017-11-01

We present a novel, compliant mechanism that provides the capability to navigate extremely confined spaces for the purpose of infrastructure inspection. Extremely confined spaces are commonly encountered during infrastructure inspection. Examples of such spaces can include pipes, conduits, and ventilation ducts. Often these infrastructure features go uninspected simply because there is no viable way to access their interior. In addition, it is not uncommon for extremely confined spaces to possess a maze-like architecture that must be selectively navigated in order to properly perform an inspection. Efforts by the imaging sensor community have resulted in the development of imaging sensors on the millimeter length scale. Due to their compact size, they are able to inspect many extremely confined spaces of interest, however, the means to deliver these sensors to the proper location to obtain the desired images are lacking. To address this problem, we draw inspiration from the field of endoscopic surgery. Specifically we consider the work that has already been done to create long flexible needles that are capable of being steered through the human body. These devices are typically referred to as ‘steerable needles.’ Steerable needle technology is not directly applicable to the problem of navigating maze-like arrangements of extremely confined spaces, but it does provide guidance on how this problem should be approached. Specifically, the super-elastic nitinol tubing material that allows steerable needles to operate is also appropriate for the problem of navigating maze-like arrangements of extremely confined spaces. Furthermore, the portion of the mechanism that enters the extremely confined space is completely mechanical in nature. The mechanical nature of the device is an advantage when the extremely confined space features environmental hazards such as radiation that could degrade an electromechanically operated mechanism. Here, we present a compliant mechanism developed to navigate maze-like arrangements of extremely confined spaces. The mechanism is shown to be able to selectively navigate past three 90° bends. The ability to selectively navigate extremely confined spaces opens up new possibilities to use emerging miniature imaging technology for infrastructure inspection.

Role of Water in the Selection of Stable Proteins at Ambient and Extreme Thermodynamic Conditions

NASA Astrophysics Data System (ADS)

Bianco, Valentino; Franzese, Giancarlo; Dellago, Christoph; Coluzza, Ivan

2017-04-01

Proteins that are functional at ambient conditions do not necessarily work at extreme conditions of temperature T and pressure P . Furthermore, there are limits of T and P above which no protein has a stable functional state. Here, we show that these limits and the selection mechanisms for working proteins depend on how the properties of the surrounding water change with T and P . We find that proteins selected at high T are superstable and are characterized by a nonextreme segregation of a hydrophilic surface and a hydrophobic core. Surprisingly, a larger segregation reduces the stability range in T and P . Our computer simulations, based on a new protein design protocol, explain the hydropathy profile of proteins as a consequence of a selection process influenced by water. Our results, potentially useful for engineering proteins and drugs working far from ambient conditions, offer an alternative rationale to the evolutionary action exerted by the environment in extreme conditions.

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:20558443

MEN16132, a novel potent and selective nonpeptide antagonist for the human bradykinin B2 receptor. In vitro pharmacology and molecular characterization.

PubMed

Cucchi, Paola; Meini, Stefania; Bressan, Alessandro; Catalani, Claudio; Bellucci, Francesca; Santicioli, Paolo; Lecci, Alessandro; Faiella, Angela; Rotondaro, Luigi; Giuliani, Sandro; Giolitti, Alessandro; Quartara, Laura; Maggi, Carlo Alberto

2005-12-28

The pharmacological characterization of the novel nonpeptide antagonist for the B2 receptor, namely MEN16132 (4-(S)-Amino-5-(4-{4-[2,4-dichloro-3-(2,4-dimethyl-8-quinolyloxymethyl)phenylsulfonamido]-tetrahydro-2H-4-pyranylcarbonyl}piperazino)-5-oxopentyl](trimethyl)ammonium chloride hydrochloride) is presented. The affinity of MEN16132 for the bradykinin B2 receptor has been investigated by means of competition studies at [3H]bradykinin binding to membranes prepared from Chinese Hamster Ovary (CHO) cells expressing the human bradykinin B2 receptor (pKi 10.5), human lung fibroblasts (pKi 10.5), guinea pig airways (pKi 10.0), guinea pig ileum longitudinal smooth muscle (pKi 10.2), or guinea pig cultured colonic myocytes (pKi 10.3). In all assays MEN16132 was as potent as the peptide antagonist Icatibant, and from 3- to 100-fold more potent than the reference nonpeptide antagonists FR173657 or LF16-0687. The selectivity for the bradykinin B2 receptor was checked at the human bradykinin B1 receptor (pKi<5), and at a panel of 26 different receptors and channels. The antagonist potency was measured in functional assays, i.e., in blocking the bradykinin induced inositolphosphates (IP) accumulation at the human (CHO: pKB 10.3) and guinea pig (colonic myocytes: pKB 10.3) B2 receptor, or in antagonizing the bradykinin induced contractile responses in human (detrusor smooth muscle: pKB 9.9) and guinea pig (ileum longitudinal smooth muscle: pKB 10.1) tissues. In both functional assay types MEN16132 exerted a different antagonist pattern, i.e., surmountable at the human and insurmountable at the guinea pig bradykinin B2 receptors. Moreover, the receptor determinants important for the high affinity interaction of MEN16132 with the human bradykinin B2 receptor were investigated by means of radioligand binding studies performed at 24 point-mutated receptors. The results obtained revealed that residues in transmembrane segment 2 (W86A), 3 (I110A), 6 (W256A), and 7 (Y295A, Y295F but not much Y295W), were crucial for the high affinity of MEN16132. In conclusion, MEN16132 is a new, potent, and selective nonpeptide bradykinin B2 receptor antagonist.

Development of dihydropyridone indazole amides as selective Rho-kinase inhibitors.

PubMed

Goodman, Krista B; Cui, Haifeng; Dowdell, Sarah E; Gaitanopoulos, Dimitri E; Ivy, Robert L; Sehon, Clark A; Stavenger, Robert A; Wang, Gren Z; Viet, Andrew Q; Xu, Weiwei; Ye, Guosen; Semus, Simon F; Evans, Christopher; Fries, Harvey E; Jolivette, Larry J; Kirkpatrick, Robert B; Dul, Edward; Khandekar, Sanjay S; Yi, Tracey; Jung, David K; Wright, Lois L; Smith, Gary K; Behm, David J; Bentley, Ross; Doe, Christopher P; Hu, Erding; Lee, Dennis

2007-01-11

Rho kinase (ROCK1) mediates vascular smooth muscle contraction and is a potential target for the treatment of hypertension and related disorders. Indazole amide 3 was identified as a potent and selective ROCK1 inhibitor but possessed poor oral bioavailability. Optimization of this lead resulted in the discovery of a series of dihydropyridones, exemplified by 13, with improved pharmacokinetic parameters relative to the initial lead. Indazole substitution played a critical role in decreasing clearance and improving oral bioavailability.

Structure-guided development of selective TbcatB inhibitors

PubMed Central

Mallari, Jeremy P.; Shelat, Anang A.; Kosinski, Aaron; Caffrey, Conor R.; Connelly, Michele; Zhu, Fangyi; McKerrow, James H.; Guy, R. Kiplin

2009-01-01

The trypanosomal cathepsin TbcatB is essential for parasite survival and is an attractive therapeutic target. Herein we report the structure-guided development of TbcatB inhibitors with specificity relative to rhodesain and human cathepsins B and L. Inhibitors were tested for enzymatic activity, trypanocidal activity, and general cytotoxicity. These data chemically validate TbcatB as a drug target, and demonstrate that it is possible to potently and selectively inhibit TbcatB relative to trypanosomal and human homologues. PMID:19769357

Discovery of an Acrylic Acid Based Tetrahydroisoquinoline as an Orally Bioavailable Selective Estrogen Receptor Degrader for ERα+ Breast Cancer

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

Burks, Heather E.; Abrams, Tinya; Kirby, Christina A.

Tetrahydroisoquinoline 40 has been identified as a potent ERα antagonist and selective estrogen receptor degrader (SERD), exhibiting good oral bioavailability, antitumor efficacy, and SERD activity in vivo. We outline the discovery and chemical optimization of the THIQ scaffold leading to THIQ 40 and showcase the racemization of the scaffold, pharmacokinetic studies in preclinical species, and the in vivo efficacy of THIQ 40 in a MCF-7 human breast cancer xenograft model.

Optimized Chemical Probes for REV-ERBα

PubMed Central

Trump, Ryan P.; Bresciani, Stefano; Cooper, Anthony W. J.; Tellam, James P.; Wojno, Justyna; Blaikley, John; Orband-Miller, Lisa A.; Kashatus, Jennifer A.; Dawson, Helen C.; Loudon, Andrew; Ray, David; Grant, Daniel; Farrow, Stuart N.; Willson, Timothy M.; Tomkinson, Nicholas C. O.

2015-01-01

REV-ERBα has emerged as an important target for regulation of circadian rhythm and its associated physiology. Herein, we report on the optimization of a series of REV-ERBα agonists based on GSK4112 (1) for potency, selectivity, and bioavailability. Potent REV-ERBα agonists 4, 10, 16, and 23 are detailed for their ability to suppress BMAL and IL-6 expression from human cells while also demonstrating excellent selectivity over LXRα. Amine 4 demonstrated in vivo bioavailability after either IV or oral dosing. PMID:23656296

Development of novel neurokinin 3 receptor (NK3R) selective agonists with resistance to proteolytic degradation.

PubMed

Misu, Ryosuke; Oishi, Shinya; Yamada, Ai; Yamamura, Takashi; Matsuda, Fuko; Yamamoto, Koki; Noguchi, Taro; Ohno, Hiroaki; Okamura, Hiroaki; Ohkura, Satoshi; Fujii, Nobutaka

2014-10-23

Neurokinin B (NKB) regulates the release of gonadotropin-releasing hormone (GnRH) via activation of the neurokinin-3 receptor (NK3R). We evaluated the biological stability of NK3R selective agonists to develop novel NK3R agonists to regulate reproductive functions. On the basis of degradation profiles, several peptidomimetic derivatives were designed. The modification of senktide with (E)-alkene dipeptide isostere generated a novel potent NK3R agonist with high stability and prolonged bioactivity.

Synthesis and P1' SAR exploration of potent macrocyclic tissue factor-factor VIIa inhibitors

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

Ladziata, Vladimir; Glunz, Peter W.; Zou, Yan

Selective tissue factor-factor VIIa complex (TF-FVIIa) inhibitors are viewed as promising compounds for treating thrombotic disease. In this contribution, we describe multifaceted exploratory SAR studies of S1'-binding moieties within a macrocyclic chemotype aimed at replacing cyclopropyl sulfone P1' group. Over the course of the optimization efforts, the 1-(1H-tetrazol-5-yl)cyclopropane P1' substituent emerged as an improved alternative, offering increased metabolic stability and lower clearance, while maintaining excellent potency and selectivity.

Comparing the clastogenic potential of atrazine with caffeine using Chinese hamster ovary (CHO) cells.

PubMed

Rayburn, A L; Bouma, J; Northcott, C A

2001-04-08

The agronomically important herbicide atrazine has been reported to cause damage to animal chromosomes at levels of atrazine found contaminating drinking water supplies. While documenting potential chromosome damage is important it is equally important to compare the damage with the potential consequences of compounds readily found in our food and water supply. In this study atrazine and caffeine, a ubiquitous food additive, were compared at equal levels and at real exposure levels for their ability to damage animals chromosomes in cell culture. Nuclei and chromosomes from treated and control cells were analyzed by flow cytometry. At extremely low levels, atrazine was found to be a more potent clastogen. Caffeine had no effect on the chromosomes at the lower levels. Both chemicals were genotoxic at the potential exposure levels with caffeine being more disruptive than atrazine. Atrazine appears to be a more potent damaging agent than caffeine at similar levels of exposure; however, the levels of caffeine one is exposed to during everyday life appears to be more damaging on the endpoints analyzed in this study than the levels of atrazine found contaminating water supplies. The advantages and limitations of whole cell clasotgenicity are also presented in light of these results.

Rational CCL5 mutagenesis integration in a lactobacilli platform generates extremely potent HIV-1 blockers.

PubMed

Secchi, Massimiliano; Grampa, Valentina; Vangelista, Luca

2018-01-30

Efforts to improve existing anti-HIV-1 therapies or develop preventatives have identified CCR5 as an important target and CCL5 as an ideal scaffold to sculpt potent HIV-1 entry inhibitors. We created novel human CCL5 variants that exhibit exceptional anti-HIV-1 features using recombinant lactobacilli (exploited for live microbicide development) as a screening platform. Protein design, expression and anti-HIV-1 activity flowed in iterative cycles, with a stepwise integration of successful mutations and refinement of an initial CCL5 mutant battery towards the generation of two ultimate CCL5 derivatives, a CCR5 agonist and a CCR5 antagonist with similar anti-HIV-1 potency. The CCR5 antagonist was tested in human macrophages and against primary R5 HIV-1 strains, exhibiting cross-clade low picomolar IC 50 activity. Moreover, its successful combination with several HIV-1 inhibitors provided the ground for conceiving therapeutic and preventative anti-HIV-1 cocktails. Beyond HIV-1 infection, these CCL5 derivatives may now be tested against several inflammation-related pathologies where the CCL5:CCR5 axis plays a relevant role.

Benzyloxynitrostyrene analogues - A novel class of selective and highly potent inhibitors of monoamine oxidase B.

PubMed

Van der Walt, Mietha M; Terre'Blanche, Gisella; Petzer, Jacobus P; Petzer, Anél

2017-01-05

This study examines a series of novel 3-benzyloxy-β-nitrostyrene analogues as a novel class of inhibitors of the monoamine oxidase (MAO) enzymes. MAO inhibitors are considered useful for the treatment of depression and Parkinson's disease, and have recently attracted attention as potential therapeutic agents for a range of disorders including Alzheimer's disease, prostate cancer and certain cardiomyopathies. This study shows that the 3-benzyloxy-β-nitrostyrene analogues are potent inhibitors of the MAO-B isoform with IC 50 values in the nanomolar range (39-565 nM). Significantly, effectiveness towards MAO-B inhibition seems to be governed by the introduction of a 4″-fluoro-substituent on the benzyloxy ring, with compound 2b exhibiting the highest degree of MAO-B inhibition potency (IC 50  = 0.039 μM) and selectivity (SI = 166) among the compounds investigated. Since some of the 3-benzyloxy-β-nitrostyrene analogues possess potencies that are comparable to that of the reversible inhibitor, safinamide (IC 50  = 0.080 μM), it may be concluded that this class may be promising leads for the development of reversible and selective MAO-B inhibitors, that may be useful for the management of Parkinson's disease. Copyright © 2016 Elsevier Masson SAS. All rights reserved.