Silver complexation and tandem mass spectrometry for differentiation of triterpenoid saponins from the roots of Pulsatilla chinensis (Bunge) Regel.
For detection and differentiation of two types of triterpenoid saponins based on different aglycons of the lupane and oleanane skeleton from the roots of Pulsatilla chinensis (Bunge) Regel, the silver ion was introduced and electrospray ionization multi-stage tandem mass spectrometry was applied to analyze eleven triterpenoid saponin silver complexes. The quasi-molecular ion [M+Ag](+) was observed in the full-scan MS spectra of all the silver complexes. The MS(2) data of the [M+Ag](+) ion provided structural information on the sugar sequence of the oligosaccharide chains and the aglycon of the saponins. There are two patterns in the cleavage pathway of oleanane-type saponins. One is elimination of the sugar chain and subsequent loss of the carboxylic group which is the same as the cleavage of lupine-type saponins. The other is loss of the distinguishing ions at m/z 72 and 28 (C(2)H(4)) followed by loss of the carboxylic group. Diagnostic fragmentation pathways of the silver complexes of the saponins allow successful identification of the two types of saponins from the roots of Pulsatilla chinensis (Bunge) Regel.
Antitumor activity of Pulsatilla chinensis (Bunge) Regel saponins in human liver tumor 7402 cells in vitro and in vivo.
Pulsatilla chinensis (Bunge) Regel is a Chinese medicinal herb for "blood-cooling" and detoxification. Now it is used for the treatment of malignant tumor, but the antitumor mechanisms and toxic side effects of P. chinensis are unclear. The present study was undertaken to investigate if P. chinensis saponins (PRS) possesses anticancer effects and toxic side effects in human liver tumor 7402 cells in vitro and vivo. 7402 cells were treated with different concentrations of PRS for 24h. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was assessed by flow cytometry. The in vivo effect of PRS on 7402 tumor cells transplanted in athymic nude mice was investigated. 15 saponins were isolated and identified from PRS. PRS inhibited the proliferation of human liver tumor 7402 cells in vitro by apoptosis. 19 days after administration of PRS (100, 200mg/kg), the weight of tumor mass was markly decreased in nude mice. The anti-tumor effect of PRS in vivo was associated with a significant increase in the 7402 apoptosis rate. Although PRS inhibited the weight of mice, it showed almost no effect on leukocyte number, liver and spleen weight index. Light microscopic histopathological examination showed that PRS had no specific lesion in organ. These results suggested that P. chinensis saponins exert potential anticancer activity in treating tumors in nude mice and no toxic side effects.
Triterpenoid saponins from Anemone hupehensis.
Four triterpenoid saponins were isolated from Anemone hupehensis. On the basis of chemical and spectroscopic evidence, two new saponins, hupehensis saponins D and E, were elucidated as 3-O-beta-D-glucopyranosyl (1-->3)-beta-D-ribopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranosyl oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside and 3-O-beta-D-glucopyransoyl (1-->3-beta-D-ribopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranosyl hederagenin-28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside. The two known saponins were identified as huzhangosides B and D.