cleavage of the two ester functions in position 3 and 5 , respectively , to carboxylic acids and further hydroxylation of the methyl groups in position 2 and 6 of the pyridine ring to the corresponding hydroxymethyl carboxylic acids constituted the major urinary metabolites accounting for 35.0 +/- 16.5 % ( i.v . ) and 32.8 +/- 20.4 % ( p.o . ) , respectively , of the dose administered .
C0014898
ester
C0007066
carboxylic acids