| Fifteen glycosides(ten nortriterpenoid saponins, three lignan-glycosides and two flavone-glycosides) were isolated from Stauntonia chinenals Decne. Thirteen of them are new compounds named yemuoside YM1(1), YM2(2), YM6(3),YM7---14(4---11),I(12) and II(13), respectively. Two are known compounds[6-hydroxyluteolin-7- -D-glycoside (14) and saponarin(15)]but were isolated from this genus for the first times. Their structures were elucidated on the basis of chemical and spectroscopic evidence.The 1H-NMR signals of nortriterpenoid saponins were studied. Complete resonance assignments of all protons were obtained by utilization of two dimensional NMR technique and typical spectral features of this type of saponins were discussed.The mass spectra of a series of bisdesmosides containing ester-glycoside linkage were measured by negative ion FAB-MS, which showed clear peaks of deprotenated molecular ions and base peaks from ester cleavage of ester-glycoside saponins. The sequence of sugar moieties could be deduced according to the fragment ions. The sites of sugar linkage in the aglycone were preliminarily estimated on the basis of the base peaks.The interconversion reactions between paeoniflorin and lacti-florin were investigated and the conversion of the latter to the former was accomplished.The interconversion reactions between triptolide and tripchlo-rolide were investigated, and a high yield method was obtained. |
