title: Metabolic fate of gallic acid orally administered to rats.
abstract: The metabolic behavior of orally administered gallic acid was investigated by HPLC and 4-O-methyl gallic acid was found to be the main metabolite in rat peripheral blood and urine. After oral administration of gallic acid, maximum concentration in portal vein and inferior vena cava occurred at 15 and 30 min, respectively. In portal vein, gallic acid was preferentially detected relative to 4-O-methyl gallic acid, whereas gallic acid and 4-0-methyl gallic acid were equally detected in inferior vena cava. On the other hand, 4-O-methyl gallic acid but not gallic acid was found in liver. The contents of gallic acid and 4-O-methyl gallic acid in urine were nearly 100 times higher than those in blood. The ratio of 4-O-methyl gallic acid to total gallic acid metabolites in urine was from 0.55 to 0.76, indicating that a considerable amount of gallic acid was excreted without being metabolized. In this study we found that gallic acid administered orally existed in the blood for 6 h at most, and more than half was metabolized to 4-O-methyl gallic acid, followed by excretion into urine.
authors.affiliation: The Drug Inspection Institute of Fujian Ports and Fujian Province, Fuzhou, P.R. China.
authors.forename: L
authors.initials: L
authors.lastname: Zong
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Nose
authors.forename: K
authors.initials: K
authors.lastname: Kojima
authors.forename: N
authors.initials: N
authors.lastname: Sakaguchi
authors.forename: K
authors.initials: K
authors.lastname: Isuzugawa
authors.forename: T
authors.initials: T
authors.lastname: Takeda
authors.forename: Y
authors.initials: Y
authors.lastname: Ogihara
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004333:Drug Administration Routes; D005707:Gallic Acid / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008099:Liver / Q000378:metabolism*; D008113:Liver Neoplasms / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005707:Gallic Acid