- Synthesis of novel diosgenyl saponin analogs and evaluation effects of rhamnose moeity on their cytotoxic activity
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Diosgenyl saponins, as a type of natural products derived from plants, are the main active component of traditional chinese medicine. Inspiringly, a large number of natural diosgensyl saponins have been shown to exert excellent toxicity to hepatocellular cancer (HCC) cells. In order to better understand the relationship between the structures and their biological effects, a group of diosgenyl saponins (1–4 as natural products and 5 and 6 as their analogs) were efficiently synthesized. The cytotoxic activity of these compounds was evaluated on human hepatocellular carcinoma (HepG2) cells. Structure–activity relationship studies showed that the pentasaccharide or hexasaccharide saponin analogs were relatively less active than their corresponding disaccharide analogue or dioscin. The extension of 4-branched rhamnose moiety on these saponin does not exhibit significant effect on their cytotoxic activity, which disclosed that a certain number and the linkage mode of rhamnose moieties could influence the cytotoxicity of steroid saponins on HepG2 cells.
- Meng, Xin,Pan, Yiwu,Liu, Tao,Luo, Chen,Man, Shuli,Zhang, Yongmin,Zhang, Yan
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- Synthesis of spirostanol saponins via gold(I)-catalyzed glycosylation in the presence of Ga(OTf)3, In(OTf)3, or HOTf
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An effective approach relying on a Lewis acid- or Br?nsted acid-assisted gold(I)-catalyzed glycosylation has been reported in the synthesis of a panel of the representative natural spirostanol saponins, namely polyphyllin D (1), polyphyllin V (2), dioscin (3), formosanin C (4), and a derivative of polyphyllin D bearing a terminal azide group (5). This approach highlights the engagement of low loadings of Ph3AuPOTf (≤ 0.5 mol%) in the presence of Ga(OTf)3, In(OTf)3, or HOTf (~10mol%) as a co-catalyst, at practical reaction rates as an alternative to the conventional ~10 mol% loadings of the gold(I) catalyst in the glycosylation. Polyphyllin D (1) was obtained in 41% overall yield over six steps compared to the maximum 30% yield in previous syntheses where conventional donors and promoters were used. By exploiting a regioselective rhamnosylation, a “one-pot” approach was adopted to assemble 1 and 5, thus further strengthening the efficiency of the gold(I)-catalyzed glycosylation.
- Ehianeta, Teddy Stephen,Shen, Dacheng,Xu, Peng,Yu, Biao
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supporting information
p. 827 - 833
(2019/07/22)
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- STEROID SAPONINS WITH ANTI-CANCER ACTIVITY
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The present invention relates to a new class of steroid saponins that have interesting biological activity. In particular the present invention relates to a class of steroid saponins in which the sugar moiety has been selectively functionalised to introdu
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Paragraph 143; 145-147; 148-149
(2018/09/08)
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- IMPROVED SYNTHESIS
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The present invention provides an improved synthesis of a class of steroid saponins. Furthermore, the present invention provides a method of selectively discriminating between the C2 and C3 hydroxyl groups of a mono-glycosylated steroid saponin – a key step in the preparation of this class of compounds. Additionally, the present invention provides a range of steroid saponin derivatives, and methods of making them.
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Page/Page column 59; 60
(2014/01/07)
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- Pathways of biotransformation of zingiberen newsaponin from Dioscorea zingiberensis C. H. Wright to diosgenin
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A new steroidal saponin-β-glucosidase from Aspergillus flavus that specifically hydrolyzed the terminal β-d-glucosyl group at the C-3 position of zingiberen newsaponin, deltonin and trillin from Dioscorea zingiberensis C. H. Wright (DZW) was purified, and characterized. The optimal temperature and pH for the new steroidal saponin-β-glucosidase was 50 C and pH 5.0. The steroidal saponin-β-glucosidase was stable at 30-60 C, and retained more than 80% activity. Further, the purified protein was analyzed by ESI-Q-TOF proteomic analyzer. The results indicated that this enzyme is a β-glucosidase of the type glycosidase hydrolase 3 (GH3). Using a combination of the steroidal saponin-β-glucosidase and steroidal saponin-α-1,2-rhamnosidase from Curvularia lunata obtained previously in our lab, the saponins zingieren newsaponin and deltonin could be converted to diosgenin. The pathways of converting zingiberen newsaponin and deltonin into diosgenin by the two key enzymes were elucidated in this study.
- Huang, Hongzhi,Zhao, Min,Lu, Li,Tan, Dawei,Zhou, Wenbin,Xiong, Chengqi,Zhao, Yang,Song, Xinbo,Yu, Liyan,Ma, Baiping
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- Synthesis of novel spirostanic saponins and their cytotoxic activity
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This study was carried out to assess the cytotoxicity of several new synthetic steroidal saponins against the human myeloid leukemia cell lines (HL-60 and U937) and against human melanoma cells (SK-MEL-1). Several diosgenyl glycosides analyzed showed strong cell growth inhibition which was associated with alterations in cell cycle progression and induction of apoptosis. Studies of cytochrome c release and caspase-9 activation suggest a main role of the intrinsic pathway of apoptosis in the mechanism of cytotoxicity caused by this kind of compounds.
- Hernandez, Juan C.,Leon, Francisco,Brouard, Ignacio,Torres, Fernando,Rubio, Sara,Quintana, Jose,Estevez, Francisco,Bermejo, Jaime
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p. 2063 - 2076
(2008/09/21)
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- The synthesis of gracillin and dioscin: Two typical representatives of spirostanol glycosides
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Two representative spirostanol saponins that have the typical structure for the sugar moiety, diosgenyl α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]- β-D-glucopyranoside (gracillin) and diosgenyl α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]- β-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.
- Zou, Chuan-Chun,Hou, Shu-Jie,Shi, Yang,Lei, Ping-Sheng,Liang, Xiao-Tian
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p. 721 - 727
(2007/10/03)
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- Synthesis of diosgenyl α-L-rhamnopyranosyl-(1 → 2)-[β-D- glucopyranosyl-(1 → 3)]-β-D-glucopyranoside (gracillin) and related saponins
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Diosgenyl α-L-rhamnopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 3)]- β-D-glucopyranoside (gracillin), a monodesmosidic saponin isolated from paris, dioscorea, and costacea species with promising cardiovascular and antitumor activities, was synthesized by s
- Li, Chuan,Yu, Biao,Liu, Meizheng,Hui, Yongzheng
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p. 189 - 195
(2007/10/03)
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- A SULFATED GLYCOSIDE FROM THE PREPARATION "TRIBESTAN"
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The chemical composition and structures of the steroid glycosides forming the active principle of the preparation "tribestan", which is used for treating impotence and female infertility, have been studied.It has been shown that together with trillin, prosapogenin A of dioscin, trillarin, dioscin, gracillin, protodioscin and protogracillin, tribestane contains a diosgenin rhamnoglucoside sulfated in position 4 of the glucose residue, the structure of which has been shown by chemical and physicochemical methods.
- Mashchenko, N. E.,Gyulemetova, R.,Kintya, P. K.,Shashkov, A. S.
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p. 552 - 555
(2007/10/02)
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- STRUCTURE CHARACTERIZATION OF HAEMOSTATIC DIOSGENIN GLYCOSIDES FROM PARIS POLYPHYLLA
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Key Word Index - Paris polyphylla; Liliaceae; polyphyllin D; pariphyllin; yunnan paiyao; haemostatic and cytotoxic diosgenin glycosides. - From Paris polyphylla var. chinensis Hare (Liliaceae), four diosgenin glycosides with haemostatic effects were isolated.The structure of the major component was elucidated by chemical and spectroscopic methods as 3-(Rha -> 2Glu)>-Ara -> 4Glu)>-β-D-glucopyranosyl)-25(R)-spirost-5-en-3β-ol.This saponin was found to be identical to three previously reported compounds to which other structures were originally assigned, namely the major component from P. polyphylla Smith, the major cytotoxic component of yunnan paiyao, and polyphyllin D from P. polyphylla grown in the Himalaya region.
- Ma, James C. N.,Lau, F. W.
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p. 1561 - 1566
(2007/10/02)
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- Studies on the Constituents of Palmae Plants. II. The Constituents of Rhapis exelsa Henry and R. humilis Bl.
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Further studies have been done on the constituents of the stems, underground parts and leaves of two Palmae plants, Rhapis exelsa Henry and R. humilis Bl.We isolated and identified dioscin, Pb, deltonin, methyl proto-dioscin, methyl proto-Pb and methyl proto-deltonin from the stems, dioscin, methyl proto-dioscin and methyl proto-Pb from the underground parts, and saponaretin (= isovitexin), methyl proto-dioscin, methyl proto-Pb and methyl proto-rhapissaponin from the leaves of R. exelsa.On the other hand we isolated and identified prosapogenin A of dioscin, dioscin, deltonin, methyl proto-prosapogenin A of dioscin, methyl proto-dioscin and methyl proto-deltonin from the stems, dioscin, methyl proto-prosapogenin A of dioscin, methyl proto-dioscin and methyl proto-Pb from the underground parts, and saponaretin, vitexin, isoorientin, methyl proto-prosapogenin A of dioscin, methyl proto-dioscin and methyl proto-Pb from the leaves of R. humilis.Methyl proto-rhapissaponin is a new furostanol saponin and its structure has been established to be 26-O-β-D-glucopyranosyl 22-O-methyl-25(R)-furost-5-en-3β,22,26-triol 3-O-4)-α-L-rhamnopyranosyl(1->4)-α-L-rhamnopyranosyl(1->4)>-2)>-β-D-glucopyranoside.This is the second report of the isolation of steroidal saponins from Palmae plants, and the results are interesting from the standpoint of chemotaxonomy. Keywords - Rhapis exelsa; Rhapis humilis; Palmae; steroidal saponin; furostanol oligoside; diosgenin; flavone glycoside; flavone C-glycoside; methyl proto-rhapissaponin
- Hirai, Yasuaki,Sanada, Shuichi,Ida, Yoshiteru,Shoji, Junzo
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p. 4003 - 4011
(2007/10/02)
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- Comparative Studies on the Constituents of Ophiopogonis Tuber and Its Congeners. II. Studies on the Constituents of the Subterranean Part of Ophiopogon planiscapus NAKAI. (1)
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Seven steroidal glycosides, tentatively named glycosides A, B(1), C(2), D(3), E(4), F(5), and G(6), were isolated from the methanol extract of the subterranean part of Ophiopogon planiscapus NAKAI (Liliaceae).The structures of these glycosides were established as so-called β-sitosterol-β-D-glucopyranoside, diosgenin 3-O-α-L-rhamnopyranosyl(12)-β-D-glucopyranoside (=prosapogenin A of dioscin) (1), diosgenin 3-O-2)>-4)>-β-D-glucopyranoside (=deltonin) (2), 26-O-β-D-gucopyranosyl-22-hydroxyfurost-5-ene-3β,26-diol 3-O-α-L-rhamnopyranosyl(12)-β-D-glucopyranoside (3), ruscogenin 1-O-α-L-rhamnopyranosyl(12)-4-O-sulfo-α-L-arabinopyranoside (4), 26-O-β-D-glucopyranosyl-22-hydroxyfurost-5-ene-3β,26-diol 3-O-2)>-4)>-β-D-glucopyranoside (=22-hydroxyl form of deltoside) (5) and 26-O-β-D-glucopyranosyl-22-hydroxyfurost-5-ene-1β,3β,26-triol 1-O-α-L-rhamnopyranosyl(12)-4-O-sulfo-α-L-arabinopyranosides (6), respectively.The relationship of steroidal glycosides of Ophiopogon japonicus KER-GAWLER, O. planiscapus NAKAI and Liriope platyphylla WANG et TANG, which are considered to be the plants of origin of the crude drug, Ophiopogonis Tuber, is also discussed.This is believed to be the first report of steroidal glycosides having a sulfate group on the sugar moiety.Keywords - Ophiopogonis Tuber; Ophiopogon planiscapus; Liliaceae; spirostanol glycoside; furostanol glycoside; sulfated steroidal glycoside; diosgenin; ruscogenin
- Watanabe, Yoshiaki,Sanada, Shuichi,Ida, Yoshiteru,Shoji, Junzo
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p. 3486 - 3495
(2007/10/02)
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