<i>N</i>-(2-Benzoylphenyl)-<scp>l</scp>-tyrosine PPARγ Agonists. 2. Structure−Activity Relationship and Optimization of the Phenyl Alkyl Ether Moiety
作者:Jon L. Collins、Steven G. Blanchard、G. Evan Boswell、Paul S. Charifson、Jeff E. Cobb、Brad R. Henke、Emily A. Hull-Ryde、Wieslaw M. Kazmierski、Debra H. Lake、Lisa M. Leesnitzer、Jürgen Lehmann、James M. Lenhard、Lisa A. Orband-Miller、Yolanda Gray-Nunez、Derek J. Parks、Kelli D. Plunkett、Wei-Qin Tong
DOI:10.1021/jm980413z
日期:1998.12.1
We previously reported the identification of (2S)-((2-benzoylphenyl)amino)-3-4-[2-(5-methyl-2-phenyloxazol-4-yl)ethoxy]phenyl}propanoic (2) (PPAR gamma pK(i) = 8.94, PPAR gamma, pEC(50) = 9.47) as a potent and selective PPAR gamma agonist. We now report the expanded structure-activity relationship around the phenyl alkyl ether moiety by pursuing both a classical medicinal chemistry approach and a solid-phase chemistry approach for analogue synthesis. The solution-phase strategy focused on evaluating the effects of oxazole and phenyl ring replacements of the 2-(5-methyl-2-phenyloxazol-4-yl)ethyl side chain of 2 with several replacements providing potent and selective PPAR gamma agonists with improved aqueous solubility. Specifically, replacement of the phenyl ring of the phenyloxazole moiety with a 4-pyridyl group to give 2(S)-((2-benzoylphenyl)amino)-3-4-[2-(5-methyl-2-pyridin-4-yloxazol-4-yl)ethoxy]phenyl}propionic acid (16) (PPAR gamma pK(i) = 8.85, PPAR gamma pEC(50) = 8.74) or a 4-methylpiperazine to give 2(S)-((2-benzoylphenyl)amino)-3-(4-2-[5-methyl-2-(4-methylpiperazin-1-yl)thiazol-4-yl]ethoxy}pheynyl)propionic acid (24) (PPAR gamma pK(i) = 8.6, PPAR gamma pEC(50) = 8.89) provided two potent and selective PPAR gamma agonists with increased solubility in pH 7.4 phosphate buffer and simulated gastric fluid as compared to 2. The second strategy took advantage of the speed and ease of parallel solid-phase analogue synthesis to generate a more diverse set of phenyl alkyl ethers which led to the identification of a number of novel, high-affinity PPAR gamma ligands (PPAR gamma pK(i)'s 6.98-8.03). The combined structure-activity data derived from the two strategies provide valuable insight on the requirements for PPAR gamma binding, functional activity, selectivity, and aqueous solubility.