Pg. Pietta et al., IDENTIFICATION OF FLAVONOID METABOLITES AFTER ORAL-ADMINISTRATION TO RATS OF A GINKGO-BILOBA EXTRACT, Journal of chromatography B. Biomedical applications, 673(1), 1995, pp. 75-80
Citations number
12
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Journal title
Journal of chromatography B. Biomedical applications
An extract of Ginkgo biloba leaves (EGb) was administered by gastric p
robe to Wistar female rats, and urine and faeces samples were collecte
d for 5 days and whole blood samples were withdrawn every 30 min for 6
h. After purification with SPE C-18 cartridges, the samples were anal
ysed by reversed-phase LC-diode array detection (LC-DAD) for residual
flavonoid glycosides, aglycones and metabolites. No glycosides or agly
cones were detected in urine, faeces or blood and extensive degradatio
n of EGb flavonoids within 24 h was detected. Among the seven differen
t phenylalkyl acids detected by LC-DAD, 3,4-dihydroxyphenylacetic acid
(I), hippuric acid (II), 3-hydroxyphenylacetic acid (III), homovanill
ic acid (IV) and benzoic acid (VII) were directly confirmed by on-line
mass spectrometry using an electrospray interface (ES-MS). Peaks V an
d VI needed to be collected and separately examined and they were foun
d to be 3-(4-hydrophenyl)propionic acid and 3-(3-hydrophenyl)propionic
acid, respectively. As further evidence, the identity of metabolites
I, II, III, IV, V and VII was confirmed by co-chromatography with auth
entic standards.