The KRASG12C protein product is an attractive, yet challenging, target for small molecule inhibition. One option for therapeutic intervention is to design small molecule ligands capable of binding to ...and inactivating KRASG12C via formation of a covalent bond to the sulfhydryl group of cysteine 12. In order to better understand the cellular off-target interactions of Compound 1, a covalent KRASG12C inhibitor, we have completed a series of complementary chemical proteomics experiments in H358 cells. A new thiol reactive probe (TRP) was designed and used to construct a cellular target occupancy assay for KRASG12C. In addition, the thiol reactive probes allowed us to profile potential off-target interactions of Compound 1 with over 3200 cysteine residues. In order to complement the TRP data we designed Compound 2, an alkyne containing version of Compound 1, to serve as bait in competitive chemical proteomics experiments. Herein, we describe and compare data from both the TRP and the click chemistry probe pull down experiments.
3-(Imidazo1,2-
apyridin-3-yl)-, its aza-analogs, and 3-(pyrazolo1,5-
apyridin-3-yl)-4-(2-acyl-(1,2,3,4-tetrahydro1,4diazepino6,7,1-
hiindol-7-yl))maleimides are very potent inhibitors of GSK3 (⩽5
nM) ...with >160 to >10,000-fold selectivity versus CDK2/4 and PKCβII.
Many 3-aryl-4-(1,2,3,4-tetrahydro1,4diazepino6,7,1-
hiindol-7-yl)maleimides exhibit potent GSK3 inhibitory activity (<100
nM IC
50), although few show significant selectivity (>100
×) versus CDK2, CDK4, or PKCβII. However, combining 3-(imidazo1,2-
apyridin-3-yl), 3-(pyrazolo1,5-
apyridin-3-yl) or aza-analogs with a 4-(2-acyl-(1,2,3,4-tetrahydro1,4diazepino6,7,1-
hiindol-7-yl)) group on the maleimide resulted in very potent inhibitors of GSK3 (⩽5
nM) with >160 to >10,000-fold selectivity versus CDK2/4 and PKCβII. These compounds also inhibited tau phosphorylation in cells and were effective in lowering plasma glucose in a rat model of type 2 diabetes (ZDF rat).
The Th17 pathway has been implicated in autoimmune diseases. The retinoic acid receptor-related orphan receptor C2 (RORγt) is a master regulator of Th17 cells and controls the expression of IL-17A. ...RORγt is expressed primarily in IL-17A-producing lymphoid cells. Here we describe a virtual screen of the ligand-binding pocket and subsequent screen in a binding assay that identified the 1-benzyl-4′,5′-dihydrospiropiperidine-4,7′-thieno2,3-cpyran-2′-carboxamide scaffold as a starting point for optimization of binding affinity and functional activity guided by structure-based design. Compound 12 demonstrated activity in a mouse PK/PD model and efficacy in an inflammatory arthritis mouse model that were used to define the level and duration of target engagement required for efficacy in vivo. Further optimization to improve ADME and physicochemical properties with guidance from simulations and modeling provided compound 22, which is projected to achieve the level and duration of target engagement required for efficacy in the clinic.
Treatment of heteroaryl-aldehydes with diethyl cyanophosphonate in the presence of a catalytic amount of LiCN affords phosphorylated cyanohydrins which are reduced in situ with SmI
2 to give ...heteroaryl-acetonitriles in generally good overall yields (50–100%). The generality of the process is demonstrated.
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An asymmetric equivalent of the Schmidt reaction permits stereocontrol in ring expansions of symmetrical cyclohexanones. The procedure involves the reaction of chiral 1,2- and 1,3-hydroxyalkyl azides ...with ketones under acid catalysis; the initial reaction affords an iminium ether that can be subsequently opened with base. A systematic study of this reaction is reported, in which ketone substrates, chiral hydroxyalkyl azides, and reaction conditions are varied. Selectivities as high as ca. 98:2 are possible for the synthesis of substituted caprolactams, with up to 1,7-stereoselection involved in the overall process. The fact that either possible migrating carbon is electronically identical provides an unusual opportunity to study a ring-expansion reaction controlled entirely by stereoelectronic factors. The mechanism of the reaction and the source of its stereoselectivity are also discussed.
Glycogen synthase kinase-3 (GSK3) is involved in signaling from the insulin receptor. Inhibitors of GSK3 are expected to effect lowering of plasma glucose similar to insulin, making GSK3 an ...attractive target for the treatment of type 2 diabetes. Herein we report the discovery of a series of potent and selective GSK3 inhibitors. Compounds 7 − 12 show oral activity in an in vivo model of type II diabetes, and 9 and 12 have desirable PK properties.
There are only a few methods for the asymmetric ring expansion of prochiral ketones. Symmetrically substituted cyclohexanones can be converted to the corresponding ring-expanded caprolactam with ...excellent 1,7-diastereoselectivity (≥93% ds) and yields (≥86%), using a chiral hydroxy azide-mediated Schmidt reaction.
The synthesis and CDK inhibitory properties of a series of indolo6,7-
apyrrolo3,4-
ccarbazoles is reported. In addition to their potent CDK activity, the compounds display antiproliferative activity ...against two human cancer cell lines. These inhibitors also effect strong G1 arrest in these cell lines and inhibit Rb phosphorylation at Ser780 consistent with inhibition of cyclin D1/CDK4.
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Synthesis of indolo6,7-apyrrolo3,4-ccarbazoles 1, a new class of cyclin D1/CDK4 inhibitors, by oxidation of the corresponding aryl indolylmaleimides 2, will be described. Two approaches to the ...synthesis of 2 were identified that required new methods for the synthesis of 7-substituted indole acetamides 3 and N-methyl (indol-7-yl)oxoacetates 6. The chemistry developed enabled introduction of functionality (−OR, NR2) at C12 and N13 facilitating structure−activity relationship (SAR) evaluation of this indolocarbazole platform.
Human rhinovirus, the chief cause of the common cold, contains a positive-sense strand of RNA which is translated into a large polyprotein in infected cells. Cleavage of the latter to produce the ...mature viral proteins required for replication is catalyzed in large part by a virally encoded cysteine proteinase (3Cpro) which is highly selective for −Q∼GP− cleavage sites. We synthesized peptidyl derivatives of vinylogous glutamine or methionine sulfone esters (e.g., Boc-Val-Leu-Phe-vGln-OR: R = Me, 1; R = Et, 2) and evaluated them as inhibitors of HRV-14 3C protease (3Cpro). Compounds 1 and 2 and several related tetra- and pentapeptide analogues rapidly inactivated 3Cpro with submicromolar IC50 values. Electrospray mass spectrometry confirmed the expected 1:1 stoichiometry of 3Cpro inactivation by 1, 2, and several other analogues. Compound 2 also proved to be useful for active site titration of 3Cpro, which has not been possible heretofore because of the lack of a suitable reagent. In contrast to 1, 2, and congeners, peptidyl Michael acceptors lacking a P4 residue have greatly reduced or negligible activity against 3Cpro, consistent with previously established structure−activity relationships for 3Cpro substrates. Hydrolysis of the P1 vinylogous glutamine ester to a carboxylic acid also decreased inhibitory activity considerably, consistent with the decreased reactivity of acrylic acids vs acrylic esters as Michael acceptors. Incorporating a vinylogous methionine sulfone ester in place of the corresponding glutamine derivative in 1 also reduced activity substantially. Compounds 1 and 2 and several of their analogues inhibited HRV replication in cell culture by 50% at low micromolar concentrations while showing little or no evidence of cytotoxicity at 10-fold higher concentrations. Peptidyl Michael acceptors and their analogues may prove useful as therapeutic agents for pathologies involving cysteine proteinase enzymes.
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