Manuifolins D, E, and F: new isoflavonoids from Maackia tenuifolia

Chemical examination of roots of Maackia tenuifolia yielded three new isoflavans, manuifolins D, E, and F, along with the known (6aR, 12aR)-pterocarpin and (6aR,12aR)-maackiain. The new compounds were established as (3R)-5'-(1,1-dimethyl-2-propenyl)-4'- O-(3-methyl-2-butenyl)- 7,2'-dihydroxyisoflavan (1), (3R)-6,5'-bis(1,1-dimethyl-2-propenyl)-7,2',4', -trihydroxyisoflavan (2), and (3R)-5'-(1-isopropylethenyl)-8-(3-methyl-2-butenyl)-7,2',4'- trihydroxyisoflavan (3), respectively, by spectroscopic methods.