ABSTRACT
Absorption. Metabolism, and Excretion. In rats, nearly 70% of an oral dose of PG was absorbed in the gastrointestinal tract, OG and DG were absorbed to a lesser extent. All three esters were hydrolyzed to gallic acid and free alcohol. The free alcohols were metabolized through the Krebs cycle. Gallic acid was methylated to yield 4-0-methyl gallic acid, which was the main metabolite found in urine either free or conjugated with glucuronic acid. Small quantities of gallic acid were also excreted as glucuronide as well as in free form. Significant amounts of unchanged esters were excreted in the feces. Similar urinary metabolites were present in rabbits in addition to small quantities of pyrogallol (Fig. 5 .I). In pigs, the metabolism was similar to that observed in rats (2-4).
