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The discovery of potent, bioavailable small molecule inhibitors of p53-HDM2 PPI led us to investigate subsequent modifications to address a CYP3A4 time-dependent inhibition liability. On the basis of the crystal structure of HDM2 in complex with 2, further functionalization of the solvent exposed area of the molecule that binds to Phe19 pocket were investigated as a strategy to modulate the molecule liphophilicity. Introduction of 2-oxo-nicotinic amide at Phe19 proved a viable strategy in obtaining inhibitors exempt from CYP3A4 time-dependent inhibition liability., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Imidazoline-based small molecule inhibitors of p53-MDM2 interaction intended for the treatment of p53 wild-type tumors are the promising structures for design of anticancer drugs. Based on fragment approach we have investigated a key role of substituents in cis-imidazoline core for biological activity of nutlin family compounds. Although the necessity of the substituents in the phenyl rings of cis-imidazoline has been shown, there are no studies in which the replacements of a halogen by other substituents have been investigated. A series of simple cis-imidazoline derivatives containing halogen, hydroxy and alkoxy-substituents were synthesized. The biological activity of the compounds was studied using assays of cytotoxicity (MTT) and p53 level. It was found that the hydroxyl-derivatives were not cytotoxic whereas the alkoxy analogues were the same or more active as halogen-substituted compounds in cell viability test. The synthesized alkoxy derivatives induced an increase of p53 level and did not promote necrotic cell death in the concentration up to 40 µM., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The YAP-TEAD protein-protein interaction is a potential therapeutic target to treat cancers in which the Hippo signaling pathway is deregulated. However, the extremely large surface of interaction between the two proteins presents a formidable challenge for a small molecule interaction disrupter approach. We have accomplished progress towards showing the feasibility of this approach by the identification of a 15-mer peptide able to potently (nanomolar range) disrupt the YAP-TEAD interaction by targeting only one of the two important sites of interaction. This peptide, incorporating non-natural amino acids selected by structure-based design, is derived from the Ω-loop sequence 85-99 of YAP., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The voltage-gated sodium (Nav) channel is the molecular determinant of action potential in neurons. Protein-protein interactions (PPI) between the intracellular Nav1.6 C-tail and its regulatory protein fibroblast growth factor 14 (FGF14) provide an ideal and largely untapped opportunity for development of neurochemical probes. Based on a previously identified peptide FLPK, mapped to the FGF14:FGF14 PPI interface, we have designed and synthesized a series of peptidomimetics with the intent of increasing clogP values and improving cell permeability relative to the parental lead peptide. In-cell screening using the split-luciferase complementation (LCA) assay identified ZL0177 (13) as the most potent inhibitor of the FGF14:Nav1.6 channel complex assembly with an apparent IC 50 of 11 μM. Whole-cell patch-clamp recordings demonstrated that ZL0177 significantly reduced Nav1.6-mediated transient current density and induced a depolarizing shift of the channel voltage-dependence of activation. Docking studies revealed strong interactions between ZL0177 and Nav1.6, mediated by hydrogen bonds, cation-π interactions and hydrophobic contacts. All together these results suggest that ZL0177 retains some key features of FGF14-dependent modulation of Nav1.6 currents. Overall, ZL0177 provides a chemical scaffold for developing Nav channel modulators as pharmacological probes with therapeutic potential of interest for a broad range of CNS and PNS disorders., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

α-Helix-mediated protein-protein interactions (PPIs) are important targets in biological research and drug development. Peptides containing d-amino acid residues are attractive molecules for inhibiting α-helix-mediated PPIs because of their wide surface area and high protease resistance. In this study, a peptide library was constructed using a one-bead one-compound format designed to isolate left-handed α-helical peptides, which are promising molecules as inhibitors of α-helix-mediated PPIs. Screening of the library against an α-helix-mediated PPI between MDM2 and p53 yielded an inhibitor of the PPI. Design and screening of the library, and biochemical and spectroscopic studies of the discovered peptide are presented., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A key series of vinblastine analogs 7-13, which contain modifications to the C20' ethyl group, was prepared with use of two distinct synthetic approaches that provide modifications of the C20' side chain containing linear and cyclized alkyl groups or added functionalized substituents. Their examination revealed the unique nature of the improved properties of the synthetic vinblastine 6, offers insights into the origins of its increased tubulin binding affinity and 10-fold improved cell growth inhibition potency, and served to probe a small hydrophobic pocket anchoring the binding of vinblastine with tubulin. Especially noteworthy were the trends observed with substitution of the terminal carbon of the ethyl group that, with the exception of 9 (R=F vs H, equipotent), led to remarkably substantial reductions in activity (>10-fold): R=F (equipotent with H)>N 3 , CN (10-fold)>Me (50-fold)>Et (100-fold)>OH (inactive). This is in sharp contrast to the maintained (7) or enhanced activity (6) observed with its incorporation into a cyclic C20'/C15'-fused six-membered ring., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Myeloid cell leukemia-1 (Mcl-1) is an important antiapoptotic protein functioning through protein-protein interactions. We discovered LSL-A6 (2-((2-carbamoyl-1-(3-(4-methoxyphenoxy)propyl)-1H-indol-6-yl)oxy)acetic acid) with a novel N-substituted indole scaffold to interfere Mcl-1 binding as a novel Mcl-1 inhibitor. Molecular modeling indicated that this compound binds with Mcl-1 by interaction with P2 and R263 hot-spots. Structure modification focused on several moieties including indole core, hydrophobic tail and acidic chain were conducted and structure-activity relationship was analyzed. The most potent compound 24d which exhibited K i value of 110nM for interfering Mcl-1 binding was obtained after hit-to-lead modification., (Copyright © 2017. Published by Elsevier Ltd.)

The long chain free fatty acid receptor 4 (FFA4/GPR120) has recently been recognized as lipid sensor playing important roles in nutrient sensing and inflammation and thus holds potential as a therapeutic target for type 2 diabetes and metabolic syndrome. To explore the effects of stimulating this receptor in animal models of metabolic disease, we initiated work to identify agonists with appropriate pharmacokinetic properties to support progression into in vivo studies. Extensive SAR studies of a series of phenylpropanoic acids led to the identification of compound 29, a FFA4 agonist which lowers plasma glucose in two preclinical models of type 2 diabetes., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A novel class of mesoionic pyrido[1,2-a]pyrimidinones has been discovered with exceptional insecticidal activity controlling a number of insect species. In this communication, we report the part of the optimization program that led to the identification of dicloromezotiaz as a potent insecticide to control a broad range of lepidoptera. Our efforts in discovery, synthesis, structure-activity relationship elucidation, and biological activity evaluation are also presented., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The Keap1-Nrf2 system is involved not only in biological defense but also in malignancy progression and chemoresistance. The ubiquitin-binding protein p62/Sqstm1 (p62), which is highly expressed in several cancers, competes with Nrf2 for Keap1 binding, leading to activation of Nrf2-mediated gene expression and survival of cancer cells. We had previously identified an inhibitor for the Keap1-phosphorylated-p62 (p-p62) protein-protein interaction (PPI), the acetonyl naphthalene derivative K67. In this study, we established facile synthetic routes for K67 and derivatives with various side chains on the C-2 position of naphthalene ring. K67 possessed high selectivity in the inhibition of Keap1-p-p62. Other derivatives showed potent Keap1-Nrf2 and Keap1-p-p62 PPI inhibitory activities, though the selectivity between the two activities was lower than K67., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Centromere-associated protein-E (CENP-E) is a mitotic kinesin which plays roles in cell division, and is regarded as a promising therapeutic target for the next generation of anti-mitotic agents. We designed novel fused bicyclic CENP-E inhibitors starting from previous reported dihydrobenzofuran derivative (S)-(+)-1. Our design concept was to adjust the electron density distribution on the benzene ring of the dihydrobenzofuran moiety to increase the positive charge for targeting the negatively charged L5 loop of CENP-E, using predictions from electrostatic potential map (EPM) analysis. For the efficient synthesis of our 2,3-dihydro-1-benzothiophene 1,1-dioxide derivatives, a new synthetic method was developed. As a result, we discovered 6-cyano-7-trifluoromethyl-2,3-dihydro-1-benzothiophene 1,1-dioxide derivative (+)-5d (Compound A) as a potent CENP-E inhibitor with promising potential for in vivo activity. In this Letter, we discuss the design and synthetic strategy used in the discovery of (+)-5d and structure-activity relationships for its analogs possessing various fused bicyclic L5 binding moieties., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Compound rac-1 was identified by high throughput screening. Here we report SAR studies and MedChem optimization towards the highly potent dual orexin receptor antagonists (S)-2 and (S)-3. Furthermore, strategies to overcome the suboptimal physicochemical properties are highlighted and the pharmacokinetic profiles of representative compounds is presented., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

In this Letter, we report the continued optimization of the N-acyl-2-aminobenzimidazole series, focusing in particular on the N-alkyl substituent and 5-position of the benzimidazole based on the binding mode and the early SAR. These efforts led to the discovery of 16, a highly potent, selective, and orally bioavailable inhibitor of IRAK-4., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

All diastereoisomeric decahydroquinoxalines representing conformationally restricted analogs of κ agonists U-50,488 and GR-89,696 have been prepared. Cis/trans configured compound 7 is by far the highest binding diastereoisomer with a Ki of 0.35 nM. Racemates 4, 6, and 7 were separated into enantiomers. (+)-(4aR,5S,8aS)-Configured enantiomer 7b was identified as a high affinity (Ki=0.25 nM) κ ligand with high selectivity over μ and δ receptors. It acts as full agonist with an EC50 value of 2.0 nM in the [(35)S]GTPγS assay, while enantiomer 7a showed an EC50 value of 1000 nM., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We synthesized two novel endomorphin-1 (EM-1) analogs by substituting the C-terminus residue with (thienyl)-α-methylene-β-amino acids (Map). Several in vitro and in vivo assays were used to determine the activity of the analogs. The two EM-1 analogs showed subnanomolar binding affinity and functional activity at the μ-opioid receptor in HEK293 cells. Tail-flick and formalin tests further revealed that the EM-1 analogs were very effective after intravenous administration. Our results indicate that compared to endomorphin-1, the (thienyl)Map modified peptides showed improved blood-brain barrier permeability., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We designed and synthesized a series of dihydroquinazolinone derivatives as selective M1 and M4 muscarinic acetylcholine receptors agonists. Introduction of the N-carbethoxy piperidine unit into a HTS hit compound followed by optimization of the amine linker and the carbamoyl moiety led to the identification of compound 1 as a potential candidate. The identified compound 1 showed high selectivity for M1 and M4 muscarinic acetylcholine receptors with M4 partial agonistic activity. In addition, compound 1 showed good brain penetration and reversed methamphetamine-induced hyperlocomotion in rats (ED50=3.0 mg/kg, sc)., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Previous studies on the natural product chlorofusin have shown that the full peptide and azaphilone structure are required for inhibition of the interaction between MDM2 and p53. In the current work, we utilized the cyclic peptide as a template and introduced an azidonorvaline amino acid in place of the ornithine/azaphilone of the natural product and carried out click chemistry with the resulting peptide. From this small library the first ever non-azaphilone containing chlorofusin analog with MDM2/p53 activity was identified. Further studies then suggested that the simple structure of the Fmoc-norvaline amino acid that had undergone a click reaction was also able to inhibit MDM2/p53 interaction. This is an example where studies of a natural product have led to the serendipitous identification of a new small molecule inhibitor of a protein-protein interaction., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Serine/threonine-specific cyclin-dependent kinases (CDKs) are key regulatory elements in eukaryotic cell cycle progression, and the dysregulation of CDKs has been implicated in cancers. Therefore, CDKs have been identified as anti-cancer targets for the development of small-molecule drugs. In this Letter, virtual screening and biological evaluation were performed to identify novel lead structures that allosterically disrupt the interaction between CDK2 and cyclin A3, which are directed toward a noncatalytic binding pocket of CDK2. Ultimately, B2 was identified as exhibiting superior CDK2/cyclin A3 inhibition activity. In addition, our results indicated that B2 exhibited antiproliferative activities against a broad spectrum of human cancer cell lines. Significantly, B2 certainly interrupted the interaction between CDK2 and cyclin A3 and exhibited a concentration-dependent trend. In summary, our results suggest that B2 is the first effective allosteric chemical small-molecule CDK2 inhibitor to be discovered, and further lead optimization may result in a series of novel anti-CDK2 agents., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Blocking the interaction between the p53 tumor suppressor and its regulatory protein MDM2 is a promising therapeutic concept under current investigation in oncology drug research. We report here the discovery of the first representatives of a new class of small molecule inhibitors of this protein-protein interaction: the dihydroisoquinolinones. Starting from an initial hit identified by virtual screening, a derivatization program has resulted in compound 11, a low nanomolar inhibitor of the p53-MDM2 interaction showing significant cellular activity. Initially based on a binding mode hypothesis, this effort was then guided by a X-ray co-crystal structure of MDM2 in complex with one of the synthesized analogs. The X-ray structure revealed an unprecedented binding mode for p53-MDM2 inhibitors., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We recently reported that diphenylsilane structure can function as a cis-stilbene mimetic. Here, we investigate whether silyl functionality can also serve as a mimetic of aliphatic cis-olefin. We designed and synthesized various silyl derivatives of oleoylethanolamide (OEA: 8), an endogenous cis-olefin-containing PPARα agonist, and evaluated their PPARα/δ/γ agonistic activity. We found that diethylsilyl derivative 20 exhibited PPARα/δ agonistic activity, and we also obtained a PPARδ-selective agonist, 32. Our results suggest that incorporation of silyl functionality is a useful option for structural development of biologically active compounds., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Compounds acting via the GPCR neurotensin receptor type 2 (NTS2) display analgesia in relevant preclinical models. The amide bond in nonpeptide NTS1 antagonists plays a central role in receptor recognition and molecular conformation. Using NTS2 FLIPR and binding assays, we found that it is also a key molecular structure for binding and calcium mobilization at NTS2. We found that reversed amides display a shift from agonist to antagonist activity and provided examples of the first competitive nonpeptide antagonists observed in the NTS2 FLIPR assay. These compounds will be valuable tools for determining the role of calcium signaling in vitro to NTS2 mediated analgesia., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We have discovered a novel class of heterocyclic sulfonamides that act as antagonists of the S1P1 receptor. While members of this series identified from a high-throughput screen showed promising levels of potency in a cell-based assay measuring the inhibition of receptor internalization, most compounds were excessively lipophilic and contained an oxidation-prone thioether moiety. As a result, such compounds suffered from poor physical properties and metabolic stability, limiting their utility as in vivo probes. By removing the thioether group and systematically developing an understanding of structure-activity relationships and the effects of lipophilicity on potency within this series, we have been able to identify potent compounds with vastly improved physical properties. A representative enantiopure triazole sulfonamide (33) has measurable bioavailability following a low (3mg/kg) oral dose in rat, highlighting an achievement of the early hit-to-lead efforts for this series., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We recently reported on the discovery of AMG 232, a potent and selective piperidinone inhibitor of the MDM2-p53 interaction. AMG 232 is being evaluated in human clinical trials for cancer. Continued exploration of the N-alkyl substituent of this series, in an effort to optimize interactions with the MDM2 glycine-58 shelf region, led to the discovery of sulfonamides such as compounds 31 and 38 that have similar potency, hepatocyte stability and rat pharmacokinetic properties to AMG 232., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A series of α-methylated analogues of the potent sRTX thiourea antagonists were investigated as rTRPV1 ligands in order to examine the effect of α-methylation on receptor activity. The SAR analysis indicated that activity was stereospecific with the (R)-configuration of the newly formed chiral center providing high binding affinity and potent antagonism while the configuration of the C-region was not significant., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Protein-protein interactions (PPIs) are important targets for the development of chemical probes and therapeutic agents. From the initial discovery of the existence of hot spots at PPI interfaces, it has been proposed that hot spots might provide the key for developing small-molecule PPI inhibitors. However, there has been no review on the ways in which the knowledge of hot spots can be used to achieve inhibitor design, nor critical examination of successful examples. This Digest discusses the characteristics of hot spots and the identification of druggable hot spot pockets. An analysis of four examples of hot spot-based design reveals the importance of this strategy in discovering potent and selective PPI inhibitors. A general procedure for hot spot-based design of PPI inhibitors is outlined., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Menin functions as an oncogenic cofactor of mixed lineage leukaemia (MLL) fusion proteins in leukaemogenesis. The menin-MLL interface is a potential therapeutic target in acute leukaemia cases. In this study, approximately 900 clinical compounds were evaluated and ranked using pharmacophore-based virtual screening, the top 29 hits were further evaluated by biochemical analysis to discover the inhibitors that target the menin-MLL interface. Two aminoglycoside antibiotics, neomycin and tobramycin, were identified as menin-MLL inhibitors with binding affinities of 18.8 and 59.9 μM, respectively. The results of thermal shift assay validated the direct interactions between the two antibiotics and menin. The results of isothermal titration calorimetry showed that the equilibrium dissociation constant between menin and neomycin was approximately 15.6 μM. We also predicted the binding modes of inhibitors at the menin-MLL interface through molecular docking analysis. The results indicated that neomycin and tobramycin competitively occupy the binding site of MLL. This study has shed light on the development of powerful probes and new therapies for MLL-mediated leukaemogenesis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Synthesis and structure-activity relationship (SAR) of a series of alkyl and cycloalkyl containing non-steroidal dissociated glucocorticoid receptor (GR) agonists is reported. This series of compounds was identified as part of an effort to replace the CF3 group in a scaffold represented by 1a. The study culminated in the identification of compound 14, a t-butyl containing derivative, which has shown potent activity for GR, selectivity against the progesterone receptor (PR) and the mineralocorticoid receptor (MR), in vitro anti-inflammatory activity in an IL-6 transrepression assay, and dissociation in a MMTV transactivation counter-screen. In a collagen-induced arthritis mouse model, 14 displayed prednisolone-like efficacy, and lower impact on body fat and free fatty acids than prednisolone at an equivalent anti-inflammatory dose., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Metalloproteases regulate a vast array of critical cellular processes such as proliferation, migration, repair, and invasion/metastasis. In so doing, metalloproteases have been shown to play key roles in the pathogenesis of multiple disorders including arteriosclerosis, arthritis, cancer metastasis, and ischemic brain injury. Therefore, much work has focused on developing metalloprotease inhibitors to provide a potential therapeutic benefit against the progression of these and other diseases. In order to produce a more potent inhibitor of metalloproteases, we synthesized multivalent displays of a metalloprotease inhibitor derived from the ring-opening metathesis polymerization (ROMP). Specifically, multivalent ligands of a broad-spectrum metalloprotease inhibitor, TAPI-2, were generated upon conjugation of the amine-bearing inhibitor with the ROMP-derived N-hydroxysuccinimide ester polymer. By monitoring the metalloprotease dependent cleavage of the transmembrane protein Semaphorin4D (Sema4D), we demonstrated an enhancement of inhibition by multivalent TAPI-2 compared to monovalent TAPI-2. To further optimize the potency of the multivalent inhibitor, we systematically varied the polymer length and inhibitor ligand density (mole fraction, χ). We observed that while ligand density plays a modest role in the potency of inhibition caused by the multivalent TAPI-2 display, the length of the polymer produces a much greater effect on inhibitor potency, with the shortest polymer achieving the greatest level of inhibition. These findings validate the use of multivalent display to enhance the potency of metalloprotease inhibitors and further, suggest this may be a useful approach to enhance potency of other small molecule towards their targets., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The lepidopteran pests such as diamondback moth are the regularly harmful pests of crops in the world, which brings enormous losses in crop production. Chlorantraniliprole is an anthranilic diamide insecticide registered for the control of lepidopteran pests with high insecticidal activity, however with uncertain binding site action target of chlorantraniliprole on ryanodine receptor, a series of new chlorantraniliprole derivatives were synthesized and the insecticidal activities of these compounds against diamondback moth were evaluated with chlorantraniliprole and indoxacarb as control. All compounds except 8h, 8p and 8t exhibited varying degree of activities against diamondback moth. Especially, compounds 8c, 8i, 8k and 8l displayed good insecticidal activities against diamondback moth and the activities are even better than that of indoxacarb during 72 h period. The Ki values of all synthesized compounds were calculated through autodocking program respectively. The relationship between calculation value of molecular docking and results of insecticidal activities indicated that the proposed specific receptor, the membrane-spanning domain protein of diamondback moth ryanodine receptor in our study might have chlorantraniliprole binding sites., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The discovery of 3,3-disubstituted piperidine 1 as novel p53-HDM2 inhibitors prompted us to implement subsequent SAR follow up directed towards piperidine core modifications. Conformational restrictions and further functionalization of the piperidine core were investigated as a strategy to gain additional interactions with HDM2. Substitutions at positions 4, 5 and 6 of the piperidine ring were explored. Although some substitutions were tolerated, no significant improvement in potency was observed compared to 1. Incorporation of an allyl side chain at position 2 provided a drastic improvement in binding potency., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

As a continuous research for discovery of new COX-2 inhibitors, we present the simple chemical synthesis, in vitro biological screening, and molecular docking study of 1H-pyrrole-2,5-dione derivatives. New synthetic compounds were evaluated for the inhibitory activities on LPS-induced PGE2 production in RAW 264.7 macrophage cells as well as the COX-1 and COX-2 inhibitory potency. Among them, compound 9d (MPO-0029) was identified as more potent and selective COX-2 inhibitor [PGE2 IC50=8.7 nM, COX-2 IC50=6.0 nM; COX-2 selectivity index (SI)=>168] than celecoxib. Molecular docking experiments were further performed against COX-2 and COX-1 isozymes to determine their probable binding models. Results of molecular docking studies revealed that compound 9d (MPO-0029) has stronger binding interaction with COX-2 than with COX-1 isozyme, and provided successfully complementary theoretical support for the obtained experimental biological data., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A convenient synthesis of four new enantiomerically pure acidic amino acids is reported and their affinity at ionotropic glutamate receptors was determined. The new compounds are higher homologues of glutamic acid in which the molecular complexity has been increased by introducing an aromatic/heteroaromatic ring, that is a phenyl or a thiophene ring, that could give additional electronic interactions with the receptors. The results of the present investigation indicate that the insertion of an aromatic/heteroaromatic ring into the amino acid skeleton of glutamate higher homologues is well tolerated and this modification could be exploited to generate a new class of NMDA antagonists., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A series of benzene sulfonamides incorporating 1,3,5-triazinyl moieties were synthesized using cyanuric chloride as starting material. Inhibition studies against human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms I, II (cytosolic) and IX, XII (transmembrane, tumor-associated) isoforms were performed with the new compounds. hCA I was modestly inhibited (KIs in the range of 87 nM-4.35 μM), hCA II was moderately inhibited by most of the new compounds (KIs in the range of 12.5-130 nM), whereas the tumor associated isoforms were potently inhibited, with KIs in the range of 1.2-34.1 nM against hCA IX and of 2.1-33.9 against hCA XII, respectively. Docking studies of some of the new compounds showed an effective binding mode within the enzyme active site, as demonstrated earlier by X-ray crystallography for structurally-related sulfonamides incorporating 1,3,5-triazinyl functionalities., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Mammalian target of rapamycin (mTOR) is a promising target for the development of anticancer medicines. Here, we report the first example for a successful application of the structure-based virtual screening to identify new mTOR inhibitors. Using the scoring function improved by implementing the ligand solvation effects on protein-ligand association, six novel mTOR inhibitors are found with IC50 values ranging from 8 to 60 μM. Because these new inhibitors are also computationally screened for having desirable physicochemical properties as a drug candidate, they deserve consideration for further development by structure-activity relationship studies to optimize the inhibitory and anticancer activities. Structural features relevant to the stabilization of the inhibitors in the ATP-binding site of mTOR are addressed in detail., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Identification of orally active, small molecule antagonists of the glucagon receptor represents a novel treatment paradigm for the management of type 2 diabetes mellitus. The present work discloses novel glucagon receptor antagonists, identified via conformational constraint of current existing literature antagonists. Optimization of lipophilic ligand efficiency (LLE or LipE) culminated in enantiomers (+)-trans-26 and (-)-trans-27 which exhibit good physicochemical and in vitro drug metabolism profiles. In vivo, significant pharmacokinetic differences were noted with the two enantiomers, which were primarily driven through differences in clearance rates. Enantioselective oxidation by cytochrome P450 was ruled out as a causative factor for pharmacokinetic differences., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Two series of novel tricyclic oxazine and oxazepine fused quinazolines have been designed and synthesized. The in vitro antitumor effect of the title compounds was screened on N87, A431, H1975, BT474 and Calu-3 cell lines. Compared to erlotinib and gefitinib, compounds 1a-1h were found to demonstrate more potent antitumor activities. Several derivatives could counteract EGF-induced phosphorylation of EGFR in cells, and their potency was comparable to the reference compounds. Compounds 1a-1h were chosen for further evaluation of EGFR and HER2 in vitro kinase inhibitory activity. Compounds 1b-1f, 1h effectively inhibited the in vitro kinase activity of EGFR and HER2 with similar efficacy as erlotinib and gefitinib., (Copyright © 2014. Published by Elsevier Ltd.)

Calcitonin gene-related peptide (CGRP) has been implicated in acute migraine pathogenesis. In an effort to identify novel CGRP receptor antagonists for the treatment of migraine, we have discovered thiazolidinone 49, a potent (Ki=30 pM, IC50=1 nM), orally bioavailable, CNS-penetrant CGRP antagonist with good pharmacokinetic properties., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A design strategy was used to identify inhibitors of activated protein C with selectivity over thrombin featured by a basic and/or aromatic functionality for binding to the S2 pocket. Our strongest inhibitor showed an IC50-material value and selectivity for APC vs thrombin similar to a compound previously reported in the literature. However, in contrast to the reference compound, our compound showed a retained coagulant effect of thrombin with increasing substrate concentration in a modified Calibrated Automated Thrombogram (CAT) method. This was likely related to our compound being inactive against FVIIa, while the reference compound showed an IC50 of 8.9 μM. Thus, the higher selectivity of our compound against all relevant coagulation factors likely explained its higher therapeutic potential in comparison to the reference compound. The data indicate that at least a 100-fold selectivity over other serine proteases in the coagulation cascade will be required for an effective APC inhibitor., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

GluN2B subtype-selective NMDA antagonists represent promising therapeutic targets for the symptomatic treatment of multiple CNS pathologies. A series of N-benzyl substituted benzamidines were synthesised and the benzyl ring was further replaced with various polycyclic moieties. Compounds were evaluated for activity at GluN2B containing NMDA receptors where analogues 9, 12, 16 and 18 were the most potent of the series, replacement of the benzyl ring with polycycles resulted in a complete loss of activity., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Neuropeptide Y (NPY) is one of the most abundant neuropeptides in the mammalian brain and exerts a variety of physiological processes in humans via four different receptor subtypes Y1, Y2, Y4 and Y5. Y2 receptor is the most abundant Y subtype receptor in the central nervous system and implicated with food intake, bone formation, affective disorders, alcohol and drugs of abuse, epilepsy, pain, and cancer. The lack of small molecule non-peptidic Y2 receptor modulators suitable as in vivo pharmacological tools hampered the progress to uncover the precise pharmacological role of Y2. Only in recent years, several potent, selective and non-peptidic Y2 antagonists have been discovered providing the tools to validate Y2 receptor as a therapeutic target. This Letter reviews Y2 receptor modulators mainly non-peptidic antagonists and their structure-activity relationships., (Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.)

A high-throughput molecular docking approach was successfully applied for the selection of potential inhibitors of the Influenza RNA-polymerase which act by targeting the PA-PB1 protein-protein interaction. Commercially available compounds were purchased and biologically evaluated in vitro using an ELISA-based assay. As a result, some compounds possessing a 3-cyano-4,6-diphenyl-pyridine nucleus emerged as effective inhibitors with the best ones showing IC50 values in the micromolar range., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A class of arylsulfonamide glucocorticoid receptor agonists that contains a substituted phenyl group as a steroid A-ring mimetic is reported. The structural design and SAR that provide the functional switching of a GR antagonist to an agonist is described. A combination of specific hydrogen bonding and lipophilic elements on the A-ring moiety is required to achieve potent GR agonist activity. This study culminated in the identification of compound 23 as a potent GR agonist with selectivity over the PR and MR nuclear hormone receptors., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The efficient synthesis of 7-substituted pyrido[2',3':4,5]furo[3,2-d]pyrimidin-4-amines and their N-aryl analogues is described. 3,5-Dibromopyridine was converted into 3-amino-6-bromofuro[3,2-b]pyridine-2-carbonitrile intermediate which was formylated with DMFDMA. Functionalization at position 7 of the tricyclic scaffold was accomplished, before or after cyclisation step, by palladium-catalyzed Suzuki-Miyaura cross-coupling while the pyrimidin-4-amines and N-aryl counterparts were synthesized by microwave-assisted formamide degradation and Dimroth rearrangement, respectively. The final products were evaluated for their potent inhibition of a series of five Ser/Thr kinases (CDK5/p25, CK1δ/ε, CLK1, DYRK1A, GSK3α/β). Compound 35 showed the best inhibitory activity with an IC50 value of 49 nM and proved to be specific to CLK1 among the panel of tested kinases., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The structure-activity relationships of T0901317 analogs were explored as RORc inverse agonists using the principles of property- and structure-based drug design. An X-ray co-crystal structure of T0901317 and RORc was obtained and provided molecular insight into why T0901317 functioned as an inverse agonist of RORc; whereas, the same ligand functioned as an agonist of FXR, LXR, and PXR. The structural data was also used to design inhibitors with improved RORc biochemical and cellular activities. The improved inhibitors possessed enhanced selectivity profiles (rationalized using the X-ray crystallographic data) against other nuclear receptors., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

We describe a medicinal chemistry approach for generating a series of 2-(1H-pyrazol-1-yl)thiazoles as EP1 receptor antagonists. To improve the physicochemical properties of compound 1, we investigated its structure-activity relationships (SAR). Optimization of this lead compound provided small compound 25 which exhibited the best EP1 receptor antagonist activity and a good SAR profile., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The discovery of a series of 6-(4-pyridyl)pyrimidin-4(3H)-ones derived from a hit compound with low molecular weight and sufficient chemical space is reported. Transformation of substituents led to subnanomolar potent inhibitors with in vivo tau phoshorylation lowering activity., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A series of tri-O-methylnorbergenin analogues 1-9 were synthesized and their antioxidant activities and inhibitory effects on tyrosinase were evaluated. Among tested analogues, compound 4 bearing cathechol moiety exhibited greater antioxidant activity and excellent inhibition on tyrosinase with IC50 value of 9.1 μM, comparable to that of corresponding positive controls. The inhibition mechanism analysis of compound 4 demonstrated that it was a mixed-type inhibitor on tyrosinase. These results suggest that these compounds may serve as a useful clue for further designing and development of novel potential tyrosinase inhibitors., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A series of methionine-proline dipeptide derivatives and their analogues were designed, synthesized and assayed against the serotype 2 dengue virus NS2B-NS3 protease, and methionine-proline anilides 1 and 2 were found to be the most active DENV 2 NS2B-NS3 competitive inhibitors with Ki values of 4.9 and 10.5 μM. The structure and activity relationship and the molecular docking revealed that L-proline, L-methionine and p-nitroaniline in 1 and 2 are the important characters in blocking the active site of NS2B-NS3 protease. Our current results suggest that the title dipeptidic scaffold represents a promising structural core to discover a new class of active NS2B-NS3 competitive inhibitors., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A β-carbonic anhydrases (CAs, EC 4.2.1.1) was recently cloned, purified and characterized kinetically in the pathogen Clostridium perfringens. We report here the first inhibition study of this enzyme (CpeCA). CpeCA was poorly inhibited by iodide and bromide, and was inhibited with KIs in the range of 1-10mM by a range of anions such as (thio)cyanate, azide, bicarbonate, nitrate, nitrite, hydrogensulfite, hydrogensulfide, stannate, tellurate, pyrophosphate, divanadate, tetraborate, peroxydisulfate, sulfate, iminodisulfonate and fluorosulfonate. Better inhibitory power, with K(I)s of 0.36-1.0 mM, was observed for cyanide, carbonate, selenate, selenocyanide, trithiocarbonate and diethyldithiocarbamate, whereas the best CpeCA inhibitors were sulfamate, sulfamide, phenylboronic acid and phenylarsonic acid, which had KIs in the range of 7-75 μM. This study thus provides the basis for developing better clostridial enzyme inhibitors with potential as antiinfectives with a new mechanism of action., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The orexin (or hypocretin) system has been identified as a novel target for the treatment of insomnia due to the wealth of biological and genetic data discovered over the past decade. Recently, clinical proof-of-concept was achieved for the treatment of primary insomnia using dual (OX1R/OX2R) orexin receptor antagonists. However, elucidation of the pharmacology associated with selective orexin-2 receptor antagonists (2-SORAs) has been hampered by the lack of orally bioavailable, highly selective small molecule probes. Herein, the discovery and optimization of a novel series of 2,5-diarylnicotinamides as potent and orally bioavailable orexin-2 receptor selective antagonists is described. A compound from this series demonstrated potent sleep promotion when dosed orally to EEG telemetrized rats., (Copyright © 2013 Elsevier Ltd. All rights reserved.)