- 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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- N-Pentenyl-Type Glycosides for Catalytic Glycosylation and Their Application in Single-Catalyst One-Pot Oligosaccharide Assemblies
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We have developed a new type of n-pentenyl-type glycosides that can be activated by catalytic amounts of promoter, Hg(NTf2)2 or PPh3AuCl/AgNTf2, at room temperature. The mild activation conditions and outstanding stability of common protection/deprotection manipulations enable the enynyl donors to have broad applications in constructing various glycosidic bonds. Furthermore, under the Hg(NTf2)2-catalyzed conditions, the sequential activation of different types of donors was achieved, based on which a gentiotetrasaccharide was synthesized via the newly developed single-catalyst one-pot strategy.
- Zu, Yujia,Cai, Chenglin,Sheng, Jingyuan,Cheng, Lili,Feng, Yingle,Zhang, Shengyong,Zhang, Qi,Chai, Yonghai
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supporting information
p. 8270 - 8274
(2019/10/14)
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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 64
(2014/01/07)
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- Efficient synthesis of α- and β-chacotriosyl glycosides using appropriate donors, and their cytotoxic activity
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Natural steroidal glycosides containing α-l-rhamnopyranosyl-(1→4)-[α-l-rhamnopyranosyl-(1→2)]-β-d-glucopyranose (chacotriose) at the oligosaccharide moiety exhibit anti-cancer and anti-herpes activities. To investigate the structure-activity relationships of the aglycone parts of chacotriosides, we developed a synthesis method for chacotriosyl glycosides having various aglycones. In the process, it was revealed that α-chacotriosyl glycosides could be obtained mainly by using a trichloroacetimidate donor, while β-chacotriosyl glycosides were afforded by using phosphite and phosphate donors. In cytotoxicity tests using the A549 and HepG2 cell lines, naturally occurring β-chacotriosyl diosgenin and cholestanol exhibited higher activities than the corresponding α-chacotriosyl glycosides.
- Miyashita, Hiroyuki,Kai, Yuuki,Nohara, Toshihiro,Ikeda, Tsuyoshi
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p. 1309 - 1315
(2008/09/21)
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- Synthesis of neosaponins and neoglycolipids containing a chacotriosyl moiety
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α-l-Rhamnopyranosyl-(1→4)-[α-l-rhamnopyranosyl-(1→2)]-β-d-glucopyranose (chacotriose) is the oligosaccharide moiety of dioscin. Chacotriosyl trichloroacetimidate was synthesized from d-glucose and l-rhamnose, and glycosylated to mevalonate (diosgenin, cholesterol, and glycyrrhetic acid) to yield dioscin and neosaponins. In order to simplify the structure of the aglycone part, the mevalonate moiety was replaced with double-chain neoglycolipids that mimicked glycosyl ceramides. A cytotoxicity test revealed the importance of the glycosidic linkage of the naturally occurring β-form and that dioscin and the neoglycolipid with the longest chain showed a moderate activity.
- Miyashita, Hiroyuki,Ikeda, Tsuyoshi,Nohara, Toshihiro
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p. 2182 - 2191
(2008/02/12)
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- Facile sythesis of dioscin and its analogues
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Three representative spirostanol saponins that have typical structure of the sugar moiety, diosgenyl 2,3-di-O-α-L-rhamnopyranosyl-β-D- glucopyranoside, diosgenyl 2,4-di-O-α-L-rhamnopyranosyl-β-D- glucopyranoside (dioscin), and diosgenyl 2,6-di-O-α-L-rhamnopyranosyl- β-D-glucopyranoside, were synthesized in a facile way. An approach to selectively mask the C3-hydroxyl of diosgenyl 4,6-O-benzylidene β-D-glucopyranoside was described. A procedure using cerium(IV) ammonium nitrate for selective removal of tert-butyldimethylsilyl group while retaining levulinyl group is afforded. Copyright
- Hou, Shujie,Zou, Chuanchun,Zhou, Liang,Lei, Pingsheng,Yu, Dequan
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p. 1220 - 1221
(2007/10/03)
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- Fluorophore-appended steroidal saponin (dioscin and polyphyllin D) derivatives
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(Chemical Equation Presented) The synthesis of three fluorophore-appended derivatives of dioscin and polyphyllin D is reported herein. Starting from trillin, dansyl derivatives A-C were prepared in overall yields of 7-12% over 7-10 steps. A study of their behavior in a variety of polar solvents suggests that dansyl derivatives A-C are capable of micellar self-assembly and can maintain cytotoxicities (IC50 = 15-18 μM) against the HeLa carcinoma cell line evaluated by standard MTT assay.
- Yang, Zhiqi,Wong, Ella Lai-Ming,Shum, Tina Yuen-Ting,Che, Chi-Ming,Hui, Yongzheng
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p. 669 - 672
(2007/10/03)
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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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- Glycosyl trifluoroacetimidates. 2. Synthesis of dioscin and Xiebai saponin I
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Two trisaccharide steroidal saponins, dioscin (1) and Xiebai saponin I (2) with various bioactivities, were efficiently synthesized using the newly developed glycosyl N-phenyl trifluoroacetimidates (10-13) as glycosylation donors. Thus, dioscin was synthesized in five steps and a 33% overall yield from diosgenin and glycosyl trifluoroacetimidates (10 and 11). Xiebai saponin I was synthesized in eight steps and a 32% overall yield from laxogenin and glycosyl trifluoroacetimidates (10, 12, and 13), whereupon, the rare steroid laxogenin was prepared from diosgenin in four steps and an overall 69% yield. All the glycosylation reactions involved in the present syntheses demonstrated that glycosyl trifluoroacetimidates were successful donors comparable to the corresponding glycosyl trichloroacetimidates.
- Yu, Biao,Tao, Houchao
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p. 9099 - 9102
(2007/10/03)
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- A facile approach to diosgenin and furostan type saponins bearing a 3β-chacotriose moiety
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Combination of a one-pot coupling technique and the use of benzyl ethers as permanent protecting groups offered a short and simple route to dioscin-type saponins. This strategy in combination with a mild reductive opening procedure of the spiroketal function in diosgenin also offered a convenient approach to bidesmosidic furostan type saponins. Me3N·BH3/AlCl3 promoted acetal opening of 3-O-TBDMS-protected diosgenin gave the 26-OH acceptor 9 into which a benzylated β-glucose moiety was introduced by a SN2-type imidate coupling. After cleavage of the silyl ether, the 3β-O-glucose and the 4-O-linked rhamnose of the chacotriose unit were introduced by a NIS/AgOTf-promoted one-pot coupling sequence utilising thioglycoside donors and their different reactivity in different solvents. After removal of a benzoyl group, the same coupling conditions were also used for the coupling of the second 2-O-linked rhamnose unit. The target substance was obtained after cleavage of the protecting benzyl ethers under Birch-type conditions, which did not affect the double bond in the steroid skeleton.
- Lahmann, Martina,Gybaeck, Helena,Garegg, Per J.,Oscarson, Stefan,Suhr, Rene,Thiem, Joachim
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p. 2153 - 2159
(2007/10/03)
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- Synthesis of neosaponins having an α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]- D-glucopyranosyl glyco-linkage
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To verify the role of the α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]- β-D-glucopyranosyl (chacotriosyl) moiety of steroidal glycosides from Solaum plants in their antitumor and antivirus activities, chacotriosides of diosgenin, cholesterol, and glycrrhetic acid were synthesized by developing our trans-oligoglycosidation. The chacotriosyl trichloroacetimidate was linked to the aglycones to afford neoglycosides as a mixture of α and β anomers, that was easily separated with ODS chromatography.
- Ikeda, Tsuyoshi,Miyashita, Hiroyuki,Kajimoto, Tetsuya,Nohara, Toshihiro
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p. 2353 - 2356
(2007/10/03)
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- Synthesis of three diosgenyl saponins: Dioscin, polyphyllin D, and balanitin 7
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Dioscin, polyphyllin D, and balanitin 7, which belong to a group of structurally similar diosgenyl saponins with promising bioactivities, were synthesized by stepwise glycosylation. Copyright (C) 1999 Elsevier Science Ltd.
- Deng, Shaojiang,Yu, Biao,Hui, Yongzheng,Yu, Hai,Han, Xiuwen
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- Heterologous expression of furostanol glycoside 26-O-β-glucosidase of Costus speciosus in Nicotiana tabacum
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Furostanol glycoside 26-O-β-glucosidase (F26G) is a specific β- glucosidase converting a furostanol glycoside (FG) to its corresponding spirostanol glycoside (SG). A cDNA encoding F26G from Costus speciosus was introduced into a heterologous plant, Nicotiana tabacum via Agrobacterium tumefaciens using a binary vector method. Successful integration of the cDNA into tobacco chromosomal DNA was confirmed by PCR analysis. F26G activity was also detected in cell-free extracts of the transgenic plantlets.
- Ichinose, Koji,You, Song,Kawano, Noriaki,Hayashi, Kaori,Yao, Xin-Sheng,Ebizuka, Yutaka
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p. 599 - 603
(2007/10/03)
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- A facile synthetic approach to a group of structurally typical diosgenyl saponins
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A facile approach was developed for synthesizing an important group of plant diosgenyl saponins, three members (dioscin, polyphyllin D, and balanitin 7) with promising bioactivities were prepared.
- Deng, Shaojiang,Yu, Biao,Hui, Yongzheng
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p. 6511 - 6514
(2007/10/03)
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- Studies on the constituents of palmae plants. VI. Steroid saponins and flavonoids of leaves of Phoenix canariensis hort. ex CHABAUD, P. humilis ROYLE var. hanceana BECC., P. dactylifera L., and Licuala spinosa WURMB.
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Steroid saponins and flavonoids of the leaves of Phoenix canariensis hort. ex CHABAUD, P. humilis ROYLE var. hanceana BECC., P. dactylifera L., and Licuala spinosa WURMB. have been investigated. Tricin 7-O-β-D-glucopyranoside (1), isorhamnetin 3-O-β-D-glucopyranoside (2), isoquercitrin (3), isorhamnetin 3-O-β-rutinoside (4), rutin (5), and methyl (25S)-proto-Pb (6) from P. canariensis, 1, 6, glucoluteolin (7), tricin 7-O-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside (8), and methyl (25S)-proto-loureiroside (9) from P. humilis var. hanceana, 1, 2, 8, methyl proto-prosapogenin A of dioscin (10), methyl proto-reclinatoside (11) and methyl proto-Pb (12) from P. dactylifera, and vitexin (13) and methyl (25S)-proto-dioscin (14) from Licuala spinosa have been isolated and identified.
- Asami,Hirai,Shoji
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p. 2053 - 2056
(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. I. Studies of the Constituents of the Subterranean Part of Liriope platyphylla Wang et Tang.
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Eight steroidal glycosides, tentatively named glycosides A(1), B(2), C(3), D(4), E(5), F(6), G(7) and H(8), were isolated from the methanol extract of the subterranean part of Liriope platyphylla Wang et Tang (Liliaceae).The structures of these glycosides were established as ruscogenin 3-O-α-L-rhamnopyranoside (1), 25(S)-ruscogenin 1-O-β-D-fucopyranosido-3-O-α-L-rhamnopyranoside (2), 25(S)-ruscogenin 1-O-α-L-rhamnopyranosyl-(1->2)-β-D-fucopyranoside (3), ruscogenin 3-O-β-D-glucopyranosyl(1->3)-α-L-rhamnopyranoside (4), a mixture of 3-O-2)>3)>-β-D-glucopyranosides of diosgenin and yamogenin (=a mixture of ophiopogonin D' and its 25(S)-isomer, 5), a mixture of 3-O-β-chacotriosides of diosgenin and yamogenin (= a mixture of dioscin and its 25(S)-isomer, 6), ruscogenin 1-sulfate 3-O-α-L-rhamnopyranoside (7), and 26-O-β-D-glucopyranosyl-22-O-methylfurost-5-ene-3β,26-diol 3-O-β-chacotrioside (=methyl proto-dioscin, 8).
- Watanabe, Yoshiaki,Sanada, Shuichi,Ida, Yoshiteru,Shoji, Junzo
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p. 1980 - 1990
(2007/10/02)
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