[Isolation and identification of steroidal saponins in total saponin from Dioscorea nipponica Makino].
ABSTRACT To investigate the water-soluble steroidal saponins in total saponin from Dioscorea nipponica Makino and look for new active compounds.
The compounds were isolated with silica gel, PTLC and HPLC, and their structures were elucidated by acid hydrolysis, physical and chemical data and spectral analysis (IR, NMR, MS, HMQC, HMBC) as well as chemical correlations.
The two steroidal saponins (water-insoluble saponin and water-soluble saponin) were isolated from the total saponin of Dioscorea nipponica Makino. The structures were elucidated as diosgenin 3-O-[alpha-L-rhamnopy ranosyl (1-->2)-[beta-D-glucopyranosyl(1-->3)]]-beta-D-glucopyranoside (I), diosgenin 3-O-[alpha-L-rhamnopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->4)-alpha-L-rhamnopyranosyl (1-->4)]-beta-D-glucopyranoside (II).
Compound II is a new steroidal saponin and firstly isolated from Dioscorea nipponica Makino. It was named as dioscin Dc.
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ABSTRACT: Nine glycosides of spirostan (1-7) and furostan (8 and 9) type steroids including a new compound, 7-oxodioscin (1), were isolated from the rhizomes of Dioscorea nipponica. The structure of 1 was established as (25R)-3beta-O-[(alpha-L-rhamnopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl)oxy]spirost-5-en-7-one by extensive spectroscopic techniques including HRESI-TOFMS, 1D and 2D NMR, and chemical methods. Known compounds were elucidated as dioseptemloside G (2), (25R)-dracaenoside G (3), orbiculatoside B (4), dioscin (5), progenin III (6), gracillin (7), (3beta3,22alpha,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurost-5-en-3-yl O-[alpha-L-rhamnopyranosyl-(1 --4)]-beta-D-glucopyranoside (8), and methylprotodioscin (9).Natural product communications 03/2013; 8(3):319-21. · 0.92 Impact Factor
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ABSTRACT: Extensive research results support the application of herbal medicine or natural food as an augment during therapy for various cancers. However, the effect of dioscin on tumor cells autophagy has not been clearly clarified. In this study, the unique effects of dioscin on autophagy of hepatoma cells were investigated. Results found that dioscin induced caspase-3- and -9-dependent cell apoptosis in a dose-dependent manner. Moreover, inhibition of ERK1/2 phosphorylation significantly abolished the dioscin-induced apoptosis. In addition, dioscin triggered cell autophagy in early stages. With autophagy inhibitors to hinder the autophagy process, dioscin-induced cell apoptosis was significantly enhanced. An inhibition of caspase activation did not affect the dioscin-induced LC3-II protein expression. Based on the results, we believed that while apoptosis was blocked, dioscin-induced autophagy process also diminished in Huh7 cells. In conclusion, this study indicates that dioscin causes autophagy in Huh7 cells and suggests that dioscin has a cytoprotective effect.Evidence-based Complementary and Alternative Medicine 11/2012; 2012:134512. DOI:10.1155/2012/134512 · 2.18 Impact Factor
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ABSTRACT: A green and efficient method for the large-scale preparation of dioscin from Dioscorea nipponica Makino, a well known traditional Chinese medicinal herb, was developed. The preparation procedure consisted of two separation steps. In the first step, several types of macroporous resins including NKA-II, DA201, DM-301, AB-8, D1400, D4020, X-5, HPD-100 and D101 were investigated in order to choose the best resin. D101 resin was selected according to its adsorption and desorption properties. Other parameters during static and dynamic procedures were also investigated. In order to obtain a pure target, a second step was established, which involved the screening of various types of macroporous resins (D900, D318, D315, D280 and D301). The results demonstrated that D900 resin was the most suitable resin for use in this study. Under these conditions, the large-scale preparation of dioscin was carried out. The purity of dioscin after the first step was increased 9.16-fold from 9.35% to 85.64% with a recovery of 81.47%. The purity of dioscin then increased to 96.55% with a recovery of 89.64% after the second purification. A total of 1.486 kg of pure dioscin was produced from 100.0 kg raw material by the developed two-step macroporous resin column chromatography method using only aqueous ethanol as the solvent. Our study provides a green and efficient protocol for industrial-scale preparation of dioscin for pharmaceutical use.Chemical Engineering Journal 11/2010; 165(1-165):281-289. DOI:10.1016/j.cej.2010.09.045 · 4.06 Impact Factor