Structure–Activity-Relationship Studies around the 2-Amino Group and Pyridine Core of Antimalarial 3,5-Diarylaminopyridines Lead to a Novel Series of Pyrazine Analogues with Oral in Vivo Activity
作者:Yassir Younis、Frederic Douelle、Diego González Cabrera、Claire Le Manach、Aloysius T. Nchinda、Tanya Paquet、Leslie J. Street、Karen L. White、K. Mohammed Zabiulla、Jayan T. Joseph、Sridevi Bashyam、David Waterson、Michael J. Witty、Sergio Wittlin、Susan A. Charman、Kelly Chibale
DOI:10.1021/jm401278d
日期:2013.11.14
Replacement of the pyridine core of antimalarial 3,5-diaryl-2-aminopyridines led to the identification of a novel series of pyrazine analogues with potent oral antimalarial activity. However, other changes to the pyridine core and replacement or substitution of the 2-amino group led to loss of antimalarial activity. The 3,5-diaryl-2-arninopyrazine series showed impressive in vitro antiplasmodial activity against the K1 (multidrug resistant) and NF54 (sensitive) strains of Plasmodium falciparum in the nanomolar IC50 range of 6-94 nM while also demonstrating good in vitro metabolic stability in human liver microsomes. In the Plasmodium berghei mouse model, this series generally exhibited good efficacy at low oral doses. One of the frontrunner compounds, 4, displayed potent in vitro antiplasmodial activity with IC50 values of 8.4 and 10 nM against the K1 and NF54 strains, respectively. When evaluated in P. berghei-infected mice, compound 4 was completely curative at an oral dose of 4 x 10 mg/kg.
Structure–Activity Relationship of 3,5-Diaryl-2-aminopyridine ALK2 Inhibitors Reveals Unaltered Binding Affinity for Fibrodysplasia Ossificans Progressiva Causing Mutants
作者:Agustin H. Mohedas、You Wang、Caroline E. Sanvitale、Peter Canning、Sungwoon Choi、Xuechao Xing、Alex N. Bullock、Gregory D. Cuny、Paul B. Yu
DOI:10.1021/jm501177w
日期:2014.10.9
There are currently no effective therapies for fibrodysplasia ossificans progressiva (FOP), a debilitating and progressive heterotopic ossification disease caused by activating mutations of ACVR1 encoding the BMP type I receptor kinase ALK2. Recently, a subset of these same mutations of ACVR1 have been identified in-diffuse intrinsic pontine ghoma (DIPG) tumors. Here we describe the structure-activity relationship for a series of novel ALK2 inhibitors based on the 2-aminopyridine compound K02288. Several modifications increased potency in kinase, thermal shift, or cell-based assays of BMP signaling and transcription, as well as selectivity for ALK2 versus closely related BMP AND TGF-beta type I receptor kinases. Compounds in this series exhibited a wide range of in vitro cytotoxicity that was not correlated with potency or selectivity, suggesting mechanisms independent of BMP or TGF-beta inhibiton. This study also highlights a potent 2-methylpyridine derivative 10 (LDN 214117) with a high degree of selectivity for ALK2 and low cytotoxicity that could provide a template for preclinical development. contrary to the notion that activating mutations of ALK2 might alter inhibitor efficacy due to potential conformational changes in the ATP-binding site, the compounds demonstrated consistent binding to a panel of mutant and wild-type ALK2 proteins. Thus, BMP inhibitors identified via activity against wild-type ALK2 signaling are likely to be of clinical relevance for the diverse ALK2 mutant proteins associated with FOP and DIPG.