Metabolism of [6]-gingerol in rats.
The metabolic fate of [6]-gingerol, one of the active constituents of Zingiber officinale Roscoe, was investigated using rats. The bile of rats orally administered [6]-gingerol was shown to contain a major metabolite (1) by HPLC analysis. Although the metabolites derived from [6]-gingerol were not detected in the urine, the ethyl acetate extract of the urine after enzymatic hydrolysis was shown to contain six minor metabolites (2-7). Their structures were determined to be (S)-[6]-gingerol-4'-O-beta-glucuronide (1), vanillic acid (2), ferulic acid (3), (S)-(+)-4-hydroxy-6-oxo-8-(4-hydroxy-3-methoxyphenyl) octanoic acid (4), 4-(4-hydroxy-3-methoxyphenyl)butanoic acid (5), 9-hydroxy [6]-gingerol (6) and (S)-(+)-[6]-gingerol (7) based on spectroscopic and chemical data. The total cumulative amount of 1 excreted in the bile and 2-7 in the urine during 60 h after the oral administration of [6]-gingerol were approximately 48% and 16% of the dose, respectively. The excretion of 2-7 in the urine decreased after gut sterilization. On the other hand, the incubations of [6]-gingerol with rat liver showed the presence of 9-hydroxy [6]-gingerol, gingerdiol (8), and (S)-[6]-gingerol-4'-O-beta-glucuronide (1). These findings suggest that the gut flora and enzymes in the liver play an important part in the metabolism of [6]-gingerol.
Nakazawa
Takahiro
T
Department of Phytochemistry, Tohoku Pharmaceutical University, Sendai, Miyagi, Japan.
Ohsawa
Keisuke
K
D000284:Administration, Oral; D000818:Animals; D001646:Bile / Q000737:chemistry; D002396:Catechols; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal; D005233:Fatty Alcohols / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D016482:Urinalysis; D014556:Urine / Q000737:chemistry
D002396:Catechols; D004365:Drugs, Chinese Herbal; D005233:Fatty Alcohols; C007845:gingerol