Ho Yin Lo

Substituted pyrazoles as novel sEH antagonist: investigation of key binding interactions within the catalytic domain.

A novel series of pyrazole sEH inhibitors is reported. Lead optimization efforts to replace the aniline core are also described. In particular, 2-pyridine, 3-pyridine and pyridazine analogs are potent sEH inhibitors with favorable CYP3A4 inhibitory and microsomal stability profiles.

Discovery, SAR and X-ray structure of 1H-benzimidazole-5-carboxylic acid cyclohexyl-methyl-amides as inhibitors of inducible T-cell kinase (Itk)

A series of novel potent benzimidazole based inhibitors of interleukin-2 T-cell kinase (Itk) were prepared. In this report, we discuss the structure-activity relationship (SAR), selectivity, and cell-based activity for the series. We also discuss the SAR associated with an X-ray structure of one of the small-molecule inhibitors bound to ITK.

Synthesis, SAR, and series evolution of novel oxadiazole-containing 5-lipoxygenase activating protein inhibitors: discovery of 2-[4-(3-{(r)-1-[4-(2-amino-pyrimidin-5-yl)-phenyl]-1-cyclopropyl-ethyl}-[1,2,4]oxadiazol-5-yl)-pyrazol-1-yl]-N,N-dimethyl-acetamide (BI 665915).

The synthesis, structure-activity relationship (SAR), and evolution of a novel series of oxadiazole-containing 5-lipoxygenase-activating protein (FLAP) inhibitors are described. The use of structure-guided drug design techniques provided compounds that demonstrated excellent FLAP binding potency (IC50 < 10 nM) and potent inhibition of LTB4 synthesis in human whole blood (IC50 < 100 nM). Optimization of binding and functional potencies, as well as physicochemical properties resulted in the identification of compound 69 (BI 665915) that demonstrated an excellent cross-species drug metabolism and pharmacokinetics (DMPK) profile and was predicted to have low human clearance. In addition, 69 was predicted to have a low risk for potential drug-drug interactions due to its cytochrome P450 3A4 profile. In a murine ex vivo whole blood study, 69 demonstrated a linear dose-exposure relationship and a dose-dependent inhibition of LTB4 production.

2-Aminobenzimidazoles as potent ITK antagonists: trans-stilbene-like moieties targeting the kinase specificity pocket.

Based on the information from molecular modeling and X-ray crystal structures, the kinase specificity pocket of ITK could be occupied upon extension of the right-hand-side of the 2-benzimidazole core of the inhibitors. 2-Aminobenzimidazoles with a trans-stilbene-like extension were designed and synthesized as novel ITK antagonists. Significant improvement on binding affinity and cellular activity were obtained through the trans-stilbene-like antagonists. Several compounds showed inhibitory activity in an IL-2 functional assay.

Itk inhibitors: a patent review

Importance of field: IL-2 inducible T-cell kinase (Itk) is a non-receptor tyrosine kinase of the Tec family. It plays an important role in T cell signaling and the production of various pro-inflammatory cytokines such as IL-2, IL-4, IL-5, IL-10 and IL-13. Inhibition of Itk has been a target for the treatment of diseases related to inflammation disorders such as psoriasis and allergic asthma. Rich resources on the structural information for Itk made discovery of novel selective Itk inhibitors blossom in the past decade. Areas covered in this review: In this report, distinct structural classes of specific Itk inhibitors are summarized and their in vitro/in vivo properties are discussed. What the reader will gain: A summary of 21 patents including 16 different chemical structure classes of Itk inhibitors. The in vivo efficacies of some of the inhibitors in animal models are also discussed. Take home message: Although some of the inhibitors show efficacy in different animal models, which implies potential for therapeutic use in human, there is not yet a chemical entity reported in clinical trials. The prospects for Itk inhibitors will rely on the quality of the compound and the validity of the target in patients within the selected therapeutic area.

Benzimidazolone as potent chymase inhibitor: modulation of reactive metabolite formation in the hydrophobic (P1) region.

A new class of chymase inhibitor featuring a benzimidazolone core with an acid side chain and a P(1) hydrophobic moiety is described. Incubation of the lead compound with GSH resulted in the formation of a GSH conjugate on the benzothiophene P(1) moiety. Replacement of the benzothiophene with different heterocyclic systems such as indoles and benzoisothiazole is feasible. Among the P(1) replacements, benzoisothiazole prevents the formation of GSH conjugate and an in silico analysis of oxidative potentials agreed with the experimental outcome.