The synthesis of gracillin and dioscin: two typical representatives of spirostanol glycosides
摘要:
Two representative spirostanol saponins that have the typical structure for the sugar moiety, diosgenyl alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 3)]-beta-D-glucopyranoside (gracillin) and diosgenyl alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-rhamnopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (dioscin), were easily synthesized by a general approach. A procedure using guanidine for the selective deblocking of acetyl while retaining benzoyl protecting groups is described. (C) 2003 Elsevier Science Ltd. All rights reserved.
Icogenin, a new cytotoxic steroidal saponin isolated from Dracaena draco
作者:Juan C Hernández、Francisco León、José Quintana、Francisco Estévez、Jaime Bermejo
DOI:10.1016/j.bmc.2004.06.009
日期:2004.8
This paper reports on the cytotoxic effect induced by a new natural steroidal saponin, icogenin, on the myeloid leukemia cell line HL-60. Icogenin was found to be a cytotoxic compound IC(50) 2.6+/-0.9microM at 72h, with growth inhibition caused by the induction of apoptosis, as determined by microscopy of nuclear changes and the fragmentation of poly(ADP-ribose) polymerase-1.
The substrate specificity of a glucoamylase with steroidal saponin-rhamnosidase activity from Curvularia lunata
作者:Bing Feng、Li-ping Kang、Bai-ping Ma、Bo Quan、Wen-bin Zhou、Yong-ze Wang、Yu Zhao、Yi-xun Liu、Sheng-qi Wang
DOI:10.1016/j.tet.2007.04.076
日期:2007.7
In previous work, we studied and reported that an enzyme from Curvularia lunata 3.4381 had the novel specificity to hydrolyze the terminal rhamnosyl at C-3 position of steroidal saponin and obtained four transformed products; the enzyme was purified and ascertained as glucoamylase (EC 3.2.1.3 GA). In this work, the enzyme exhibiting steroidal saponin-rhamnosidase activity was systematically studied on 21 steroidal saponins and 6 ginsenosides. The results showed that the alpha-1,2-linked end-rhamnosyl residues at C-3 position of steroidal saponins could be hydrolyzed to corresponding secondary steroidal saponins, among which 18 compounds were isolated and identified, including 3 new secondary compounds. For the furostanosides having glucosyl residues at the C-26 position, hydrolysis occurred first at end- rhamnosyl at C-3 position to produce secondary furostanosides. The reaction of hydrolyzing glucosyl at C-26 position depended considerably on longer reaction times yielding the corresponding secondary spirostanosides ( without rhamnosyl and glucosyl residues). The enzyme had the strict specificity for the terminal alpha-1,2-linked rhamnosyl residues of linear chain, or the terminal alpha-1,2-linked rhamnosyl residues with branched chain of 1,4-linked glycosyl residues of sugar chain at C-3 position of steroidal saponins, it was not specific for different aglycones, different glycons, and the number of glycon of sugar chain of steroidal saponin. The end- rhamnosyl of ginsenosides and p-nitrophenyl-a-L-rhamnopyranoside (pNPR) could not be hydrolyzed by the enzyme from C. lunata. (c) 2007 Elsevier Ltd. All rights reserved.
Synthesis of diosgenyl α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→3)]-β-d-glucopyranoside (gracillin) and related saponins
作者:Chuan Li、Biao Yu、Meizheng Liu、Yongzheng Hui*
DOI:10.1016/s0008-6215(97)10050-7
日期:1998.1
Diosgenyl alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 3)]-beta-D-glucopyranoside (gracillin), a monodesmosidic saponin isolated from paris, dioscorea, and costacea species with promising cardiovascular and antitumor activities, was synthesized by stepwise glycosylation. (C) 1998 Elsevier Science Ltd. All rights reserved.
Steroidal saponins from Paris polyphylla var. yunnanensis
作者:Xia Wu、Lei Wang、Hui Wang、Yi Dai、Wen-Cai Ye、Yao-Lan Li
DOI:10.1016/j.phytochem.2012.05.034
日期:2012.9
Eleven steroidal saponins, along with seven known steroidal saponins, were isolated from rhizomes of Paris polyphylla var. yunnanensis. Their chemical structures were elucidated on the basis of spectroscopic analyses and acid hydrolysis. Two of these compounds contained a spirostanol saponin aglycone, hitherto unknown in Nature. The isolated compounds were tested for their cytotoxic effects on human nasopharyngeal carcinoma epithelial (CNE) cells, and seven compounds displayed more potent inhibitory effects than cisplatin (the positive control). One compound with diosgenin and tetrasaccharide moieties possessed the strongest inhibitory effect on CNE cells through the induction of apoptosis and cell cycle arrest. (C) 2012 Elsevier Ltd. All rights reserved.