203919-27-1Relevant articles and documents
Structure-activity relationships of a novel class of endothelin-A receptor antagonists and discovery of potent and selective receptor antagonist, 2-(benzo[1,3]dioxol-5-yl)-6-isopropyloxy-4- (4-methoxyphenyl)-2H-chromene-3-carboxylic acid (S-1255). 1. Study on structure-activity relationships and basic structure crucial for ETA antagonism
Ishizuka, Natsuki,Matsumura, Ken-Ichi,Sakai, Katsunori,Fujimoto, Masafumi,Mihara, Shin-Ichi,Yamamori, Teru
, p. 2041 - 2055 (2007/10/03)
A novel series of endothelin-A (ETA) selective receptor antagonists having a 2H-chromene skeleton are described. A lead compound, 2-(benzo[1,3] dioxol-5-yl)-2H-chromene-3-carboxylic acid (3), was found by modifications of our own angiotensin II antagonist. A structure-activity relationship (SAR) study of 3 reveals that the structural requirements essential for potent and selective ETA receptor binding affinity are the m,p-methylenedioxyphenyl, carboxyl, and isopropoxy groups at the 2-, 3-,and 6-positions, respectively, on the (R)-2H-chromene skeleton. The substituent at the 4-position is also important for improving the activity, and various hydrophobic functional groups of 6-9 ? such as liner, branched, and cyclic aliphatic groups, unsubstituted and substituted aryl groups, and even halogen atoms were acceptable. These results suggest that (R)-2-(benzo[1,3]dioxol-5-yl)-6-isopropoxy-2H-chromene-3-carboxylic acid, formula 108, is the crucial basic structure to be recognized by the ETA receptor. The most potent compound is (R)-48 (S-1255), which binds to the ETA receptor with an IC50 value of 0.19 nM and is 630-fold selective for the ETA receptor than for the ETB receptor. This compound has 55% oral bioavailability in rats. On the basis of the SAR, the roles of each substituent in the receptor binding are discussed.
