[Studies on biotransformation of chemical constituents of tongmai formula by human intestinal flora].

To study the chemical constituents in Tongmai formula (TMF) after biotransformation by human intestinal flora (HIF), water extract of TMF was anaerobically incubated with HIF at 37 degrees C. Column chromatographic methods over silica gel, Sephadex LH-20 and semi-preparative high-performance liquid chromatography as well as recrystallization were used to isolate and purify the chemical constituents in TMF after biotransformation by HIF. The chemical structures of isolated compounds were identified on the basis of MS and NMR data. Twenty-six compounds were obtained and identified as phenylpropionic acid (1), 6"-O-acetylpuerarin (2), formononetin(3), daidzein(4), p-hydroxyphenylpropionic acid (5), 3-indolepropionic acid (6), genistein (7), isoformononetin (8), isoononin (9), a mixture of (-)-puerol B-2"-O-glucopyranoside (10a) and (+) -puerol B-2"-O-glucopyranoside (10b), 8-hydroxydaidzein (11), puerol A (12), 3'-methoxy-6"-O-acetylpuerarin (13), 6"-O-acetyldaidzin (14), 3'-methoxydaidzin (15), puerol B (16), 3-methyluracil (17), genistin (18), daidzin (19), 3'-methoxypuerarin (20), mirificin (21), swertiamarin (22) , daidzein-7, 4'-O-glucoside (23), adenine (24), 3'-hydroxypuerarin (25), and puerarin (26). After biotransformation by HIF, the glycosides in TMF were transformed into aglycone and/or less glycosyl compounds along with some hydroxylation and demethylation reactions. Therefore, the glycosides in the TMF are the pro-drug.