Studies on saponins from seeds of Trigonella foenum-graecum Ⅱ.Isolation and structural elucidation for two new saponins B and C / 中草药

ABSTRACT

Object To do detail investigation of the saponins from the Chinese materia medica Huluba (the seeds of Trigonella foenum graecum L ) Methods The pure saponins from the total saponins were isolated by employing the column chromatography and dry column chromatography of silica gel H Their chemical structures were elucidated by 13 C NMR , FAB MS, DEPT spectroscopic evidence and the results of the fraction hydrolysis of acquiring their secondary glucosides were obtained Results Two new saponins B and C were isolated and both were the glucosides consisted by four molecules of sugar with diosgenin The chemical structure of B is diosgenin 3 O ? L rhamnopyranosyl (1→3) ? L rhamnopyranosyl (1→4) ? D glucopyranosyl (1→4) ? D glucopyranoside And saponin C is diosgenin 3 O ? D glucopyranosyl (1→4) ? L rhamnopyranosyl (1→4) ? D glucopyranosyl (1→4) ? D glucopyranoside Conclusion Saponins B and C are two new ones with four molecules of sugar respectively