Studies in detoxication. 57. The structure of the glucuronides from 2- and 4-quinolones and the orientation of biological hydroxylation in quinolones

Abstract

The glucuronide obtained by feeding carbostyril (2-quinolone) to rabbits was proved to be 2-quinolonyl-6-glucosiduronic acid, since it yields 26-dihydroxy-quinoline on hydrolysis. The crystalline glucuronide (m.p. 208[degree]) obtained in small yield from the urine of rabbits receiving 4-quinolone was proved to be 4-quinolonyl-6-glucosiduronic acid, since after feeding with 4:6-dihydroxyquinoline the same glucuronide can be isolated. The main glucuronide isolated after feeding with 4-quinolone appears to be 4-quinolonyl-3-glucosiduronic acid, since it yields 3:4-dihydroxyquinoline on hydrolysis. The positions of metabolic hydroxylation of the 2-and 4-quinolones are the same as those found when these components are nitrated.