New hepatoprotective isoflavone glucosides from Pueraria lobata (Willd.) Ohwi

Two new isoflavone glucosides, 3'-methoxyneopuerarin A (1) and 3'-methoxyneopuerarin B (2), together with nine known isoflavones including puerarin (3), neopuerarin A (4), neopuerarin B (5), daidzin (6), daidzein (7), 3'-methoxypuerarin (PG-3) (8), puerarin xyloside (9), mirificin (10), 3'-hydroxypuerarin (11) were isolated from the water extraction of the dried roots of Pueraria lobata (Willd.) Ohwi. Their structures were elucidated by the means of spectroscopic and chromatographic analysis methods. All compounds were evaluated for their hepatoprotective activity on HepG2 cells. All of them showed statistically significant hepatoprotective effect.