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 IC 50 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.