HIV gp41 binding phenolic components from Fraxinus sieboldiana var. angustata

By means of HIV gp41 binding affinity directed chromatographic fractionation, three phenylethanoid glycosides; calceolarioside A (1), calceolarioside B (2) and acteoside (3), along with four hydroxycoumarins; esculin (4), fraxin (5), fraxetin (6) and esculetin (7), and one lignan, (-)-olivil (8) were isolated from the n-butyl alcohol fraction of Fraxinus sieboldiana var. angustata. Among the isolated compounds, calceolarioside B (2) and esculetin (7) showed moderate binding affinity on HIV gp41 with IC50 values of 0.1 mg/ml and 0.5 mg/ml, respectively. Calceolarioside A (1), calceolarioside B (2), acteoside (3), and (-)-olivil (8) were isolated for the first time from this plant.