Yuanxiang Wang

Synthesis and c-Met Kinase Inhibition of 3,5-Disubstituted and 3,5,7-Trisubstituted Quinolines: Identification of 3-(4-Acetylpiperazin-1-yl)-5-(3-nitrobenzylamino)-7- (trifluoromethyl)quinoline as a Novel Anticancer Agent

By use of an improved synthetic strategy, a series of 3,5-disubstituted and 3,5,7-trisubstituted quinolines were readily prepared. 3,5,7-Trisubstituted quinolines 21a-c, 21l, and 27a-c were identified as the most potent c-Met inhibitors with IC(50) of less than 1.0 nM. Compound 21b showed the most promising overall PK profile and has high potency and extraordinary selectivity to c-Met against c-Met family member Ron and 12 other tyrosine kinases. It produced constitutive inhibition of c-Met phosphorylation in c-Met dependent cell lines. At doses of 100 mg/kg, compound 21b showed statistically significant tumor growth inhibition (68-69%) in both NIH-3T3-TPR-Met and U-87 MG human gliobastoma xenograft models. These results clearly indicated that compound 21b is a potent and highly selective c-Met inhibitor. Its favorable in vitro and in vivo profiles warrant further investigation.

Discovery of novel c-Met kinase inhibitors bearing a thieno[2,3-d]pyrimidine or furo[2,3-d]pyrimidine scaffold

A series of thieno[2,3-d]pyrimidines and furo[2,3-d]pyrimidines were synthesized and evaluated for the c-Met inhibition. Thieno[2,3-d]pyrimidine 6b stood out as the most potent showing an IC(50) of 35.7 nM. This compound displayed high inhibitory effect on cell proliferation in BaF3-TPR-Met cells and showed high selectivity for c-Met family against other 14 tested kinases. However, compound 6b was found ineffective in the c-Met-dependent U-87MG human gliobastoma xenograft model that may be relevant to its poor PK profile.

Synthesis Study on Marmycin A: Preparation of the C3'-Desmethyl Analogues

Total synthesis of natural product marmycin A was studied. An expeditious synthetic strategy for the key fragment 8-amino-3-methylbenz[a]anthraquinone (1) was established with decarboxylative alkylation, Pd(OAc)(2)-catalyzed cyclization, aromatization, and C-N coupling as the key steps. However, final assembly of marmycin A was hampered by the failure to obtain the carbohydrate fragment 2. Instead, a small library of desmethyl analogues of marmycin A was prepared in moderate yields by using the InBr(3)-catalyzed C- and N-glycosidation reaction. The absolute configuration of these compounds was confirmed by comparison of their spectroscopic data with that reported for marmycin A, and by X-ray analysis.

Multisubstituted quinoxalines and pyrido[2,3-d]pyrimidines: Synthesis and SAR study as tyrosine kinase c-Met inhibitors.

Two series of new analogues were designed by replacing the quinoline scaffold of our earlier lead 2 (zgw-atinib) with quinoxaline and pyrido[2,3-d]pyrimidine frameworks. Moderate c-Met inhibitory activity was observed in the quinoxaline series. Among the pyrido[2,3-d]pyrimidine series, compounds 13a-c possessing an O-linkage were inactive, whilst the N-linked analogues 15a-c retained c-Met inhibitory potency. Highest activity was observed in the 3-nitrobenzyl analog 15b that showed an IC(50) value of 6.5 nM. Further structural modifications based on this compound were undergoing.

Expeditious one-pot synthesis of C3-piperazinyl-substituted quinolines: key precursors to potent c-Met inhibitors.

An effective one-pot synthesis of quinolines bearing diverse C3-piperazinyl functions was developed by using a modified Friedländers protocol. The method not only enables the synthesis of our early reported c-Met inhibitor on a large scale, but also provides a way to generate novel multi-substituted quinolines for further structure-activity relationship (SAR) study.

Further SAR studies on 3,5-diamino-7-trifluoromethylquinolines as highly potent tyrosine kinase c-Met inhibitors: efforts to correct hERG inhibition

A preclinical study on our previously discovered highly potent c-Met inhibitor 1 (zgwatinib) demonstrated its significant toxicity, and a SAR campaign was conducted to finely tune down the hERG inhibition without affecting the c-Met potency. Compounds 11, 12 and 39 stood out as new c-Met inhibitors with IC50 values of <3.0 nM and being nearly inactive against hERG channels.