Isolation and structure determination of cypritibetquinone A and B, two new phenanthraquinones from Cypripedium tibeticum / 药学学报

ABSTRACT

Aim To study the chemical constituents of Cypripedium tibeticum. Methods Compounds were isolated by repeated silica gel chromatography and purified on Sephadex LH-20 and structures were determined by spectral analysis. Results Cypritibetquinones A and B were isolated from the ethyl acetate residue and their structures were determined as 7-hydroxy-2-methoxy-1, 4-phenanthraquinone ( 1 ) and 7-hydroxy-2,10-dimethoxy-1,4-phenanthraquinone ( 2 ), respectively, by extensive spectral analyses. Conclusion Cypritibetquinones A and B are two new phenanthraquinones.