Studies On The Metabolism Of Baicalin In Rat And Biological Activities Of The Metabolites

Scutellariae Radix, the root of Scutellariae baicalensis Georgi, is widely used in traditional Chinese formulations, which has been shown to possess anti-allergic, anti-inflammatory activity including hepatitis, anti-oxidation and has effects on hyperlipidemia and lipolysis. Baicalin is one of the major active constituents in it. On the basis of the summary of their chemistry, pharmacology, and metabolic chemistry, we studied the metabolism of baicalin in rat and biological activities of the metabolites.Baicalin extracted and refined from Scutellariae Radix with the method of water extracting and ethanol depositing was orally administered to rats. With silica gel column, resin column, Sephadex LH-20, PHPLC and PTLC methods, we isolated 14 compounds from urine and 4 metabolites from the feces of the rats. On the basis of physicochemical properties and analysis of MS, NMR data, the structures of 12 compounds from urine were identified as baicalin(l), baicalein 6,7-di-O-β-glucopyranuronoside(2), baicalein 7-O-β-D-glucopyranuronoside methyl ester(3), baicalein 7-O-β-D-glucopyranuronoside ethyl ester(4), baicalein(5), 7-methoxy-baicalein(6), 6-methoxy-baicalein(7), 5-methoxy-baicalein(8), 6-methoxy-baicalein 7-O-β-D-glucopyranuronoside ethyl ester(9), 3-oxo-3-phenyl-propionic acid hydrazide(10), (2-oxo-2-phenyI-ethyl)-urea(11), and benzoic acid(12). 1, 5,...