Bioisosteric Replacement of the Pyrazole 5-Aryl Moiety of <i>N</i>-(Piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1<i>H</i>-pyrazole-3-carboxamide (SR141716A). A Novel Series of Alkynylthiophenes as Potent and Selective Cannabinoid-1 Receptor Antagonists
作者:Shi-Liang Tseng、Ming-Shiu Hung、Chun-Ping Chang、Jen-Shin Song、Chia-Liang Tai、Hua-Hao Chiu、Wan-Ping Hsieh、Yinchiu Lin、Wan-Ling Chung、Chun-Wei Kuo、Chien-Huang Wu、Cheng-Ming Chu、Yen-Shih Tung、Yu-Sheng Chao、Kak-Shan Shia
DOI:10.1021/jm800066v
日期:2008.9.11
Replacing the conventional pyrazole 5-aryl substituent of 1 (SR141716A) with the 2-thienyl rnoiety appended with ail appropriate alkynyl unit, a novel class of 5-(5-alkynyl-2-thienyl)pyrazole derivatives, behaving as highly potent CB1 receptor antagonists with good CB1/2 selectivity, was discovered, many of which, its typified by compound 18, showed significant weight reduction in diet-indUced obese Mouse model, thus pharmacologically validating that the bioisosteric replacement described above is viable. Also encouraging was the finding that a subtle structural modification of the newly developed series could result in a distinct difference in the intrinsic property, as demonstrated by compounds 12 (NA) and its methylated structural isomers 15 (PA) and 18 (IA). Moreover, current structure-activity relationship Studies revealed that around the pyrazole 5-position of 1, a deep and flat crevice surrounded by a sequence of hydrophobic/aromatic residues as indicated by the CB I-receptor homology model might exist in the binding site.