Flavonoids from Bauhinia glauca subsp. pernervosa.

Seven flavonoids were isolated from Bauhinia glauca subsp. pernervosa, and their structures were elucidated as 6-methyl homoeriodictyol (1), bauhiniaside A (2), bauhiniasin (3), 2',4'-dihydroxy-4-methoxydihydrochalcone-4'-O-beta-D-glucopyranoside (4), farrerol (5), homoeriodictyol (6), and 2',4'-dihydroxy-4-methoxydihydrochalcone (7) on the basis of spectroscopic analysis. Compounds 1, 2 and 3 are new flavonoids, compound 4 is a new natural product, its NMR data is reported for the first time. Compounds 5 and 7 were isolated from the genus Bauhinia for the first time, and compound 6 was isolated from the plant for the first time.