the main metabolites were products of ( i ) oxidation of the 1,4-dihydropyridine ring to the corresponding pyridine , ( ii ) hydrolysis of the 5-isopropyl ester or 3-methyl ester group to carboxylic acid , and/or ( iii ) hydroxylation of the 6-methyl group or methyl group of the isopropyl ester chain .
C0007066
carboxylic
C0014898
ester