1987 Volume 2 Issue 5 Pages 487-496
Three new metabolites of budralazine, an antihypertensive drug, were isolated from urine, bile and liver-perfusion effluent of rats, and their structures were identified by direct comparison with authentic samples.
A major urinary metabolite was identified as the mercapturic acid conjugate of mesityl oxide, namely, N-acetyl-S-(1, 1-dimethyl-3-oxo)butyl-L-cysteine (M-14).
A major biliary metabolite was identified as 1-[2-(1, 3-dimethyl-3-S-L-glutathionyl-butylidene)hydrazino]phthalazine(M-15). It was assumed that M-15 was derived from addition of glutathione to the terminal carbon-carbon double bond of budralazine. M-15 had two geometrical isomers with respect to the hydrazone linkage. Two isomers were clearly separated by HPLC.
A major metabolite of liver-perfusion was confirmed as the carboxylic acid analogue of budralazine, namely, 4-(1-phthalazinyl)hydrazino-2-methyl-trans-2-pentenoic acid (M-16). M-16 was also found to be a major plasma metabolite.
