First Synthesis of a Bidesmosidic Triterpene Saponin by a Highly Efficient Procedure

Yu, Bo; Xie, Jianming; Deng, and Shaojiang; Hui, Yongzheng

doi:10.1021/ja9926818

Cited by 87 publications

(41 citation statements)

References 12 publications

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“…15 With 3,6-diol 6 in hand, we next applied a one-pot sequential glycosylation to the synthesis of trisaccharide acceptor 9. To this end, 6-O-silylated trichloroacetimidate 7 16 (1.1 equiv.) was regioselectively coupled with diol 6 using catalytic amount of TMSOTf (0.07 equiv.)…”

Section: Resultsmentioning

confidence: 99%

Synthesis and antitumor activities of glucan derivatives

Du¹,

Gu²,

Yang³

et al. 2004

Tetrahedron

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Abstract-A highly efficient and practical method for the preparation of]-D-Glc-OMe was described. A dendritic nonasaccharide was also synthesized. The antitumor activities of hexasaccharide, the dendrimer, their sulfated derivatives, together with the natural glucan -protein and the corresponding polysaccharide isolated from barmy mycelium of Grifola frondosa, were preliminarily investigated based on Sarcoma-180 studies in mice tests. Our results suggest that the sulfated branching oligosaccharide and natural glycoprotein have better antitumor activities comparing to the parent sugar residue (oligosaccharide or polysaccharide). q

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Section: Resultsmentioning

confidence: 99%

Synthesis and antitumor activities of glucan derivatives

Du¹,

Gu²,

Yang³

et al. 2004

Tetrahedron

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“…The disaccharides in our study were previously used in saponin synthesis but with different aglycons 10,12,14,15,19,20) using the Koenigs-Knorr method, giving the desired saponins in low yields. We chose to use trichloroacetimidates 21) as donors in our glycosylation reactions, this being a highly efficient method for coupling as reported by Biao Yu et al for the synthesis of oleanolic acid saponins 22,23) and by us for the synthesis of a-hederin.…”

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confidence: 99%

Synthesis and Hemolytic Activity of Some Hederagenin Diglycosides

Chwalek

Plé

Voutquenne-Nazabadioko

2004

Chem. Pharm. Bull.

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Saponins are steroid or triterpenoid glycosides which are widespread in terrestrial and marine plants and possess various biological and pharmacological activities. 1) One of the first known activities of saponins is their ability to lyse erythrocytes.1) This hemolytic activity has long been studied and the origin of the phenomenon is generally ascribed to their amphiphilic properties, but the exact mechanism is not yet known especially when considering the structural diversity of saponins. It has been shown that saponins are capable of interacting with membrane cholesterol 2-4) forming pits and holes which produce a destabilisation of the membrane by a micellar type-arrangement. 5) Some authors have postulated that the last step consists of an enzymatic deglycosylation that releases the aglycon and produces cell lysis.6,7) Aglycons can show weak hemolytic activity but are not solely responsible for cell destruction. While the aglycon is very important in considering structure-activity relationships, the contribution of the sugar moiety is also significant. 8) Hemolytic activity depends on the nature, number and sequence of the sugars in the saponin.Our laboratory has long been interested in saponin isolation and identification, and, more recently, in their hemolytic structure-activity relationships. The study of hemolytic activity is a way of gaining insight into how saponins react at the membrane surface. We have compared many saponins with various triterpenoid aglycons and, as Schlösser and Wulff,8) have established that a polar substitution in ring A and weak polar substitution in rings D and E increases hemolytic activity and that monodesmosidic triterpenoid saponins are generally more active than bidesmosidic ones. 9)Structure-activity relationships of some synthetic saponins of oleanolic acid, 10-12) methyl oleanolate 13) and of other triterpenoid or steroid aglycons 14,15) have been previously established. It is thus known that the effect of the sugar residue on hemolytic activity is not transferable from one aglycon to one another. We wished to complete our study by analyzing the influence of the sugar units on hemolytic activity using hederagenin as the exclusive aglycon. Hederagenin saponins are largely represented in nature and possess many biological activities such as hemolytic, antiviral, antimicrobial, fongicidal, molluscicidal, or cytotoxic.1) With aglycons such as hederagenin, possessing a carboxylic group in position 28, it is known that hemolytic activity is greater when the free acid is esterified as a methyl ester. Unfortunately, no comparative structure-activity relationship have been performed on both the free acid and the methyl ester saponins to establish if the same factors systematically influence hemolytic activity. 8,16) We thus wished to synthesize the natural saponin 3hederagenin (isomaltosyl-hederagenin) 6 (Chart 1), and their corresponding methyl esters (1a, 2a, 3a, 4a, 5a, 6a). Compound 1 has been isolated from Fatsia japonica 17) and from the leaves of Barbarea vulgaris and ...

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“…Starting from 1,3,4,6-tetra-O-acetyl-2-deoxy-2-phthalimido-β-D-glucopyranose (2), 11 compound 3 was obtained as a pure β-anomer (J 1,2 ＝8.8 Hz) by reacting 2 with p-MeO-C 6 H 4 OH under the promotion of BF 3 •Et 2 O in 81.9% yield. After removal of acetyl groups in 3, 6-OH was protected selectively by Tr group 12 and then 3,4-OHs were protected by acetyl groups in situ to produce compound 5 quantitatively. Cleavage of Tr protecting group in 5 with FeCl 3 •6H 2 O 13 afforded the key glycosyl acceptor 6 in 69.5% yield.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of an Ursolic Acid Saponin with N‐Acetylglucosamine‐containing Trisaccharide Residue

Wang

et al. 2006

Chin. J. Chem.

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The focus of this work is the synthesis of an ursolic acid saponin with an N-acetylglucosamine-containing trisaccharide residue. Therefore, ursolic acid 3-yl α-L-arabinopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→6)-2-acetamido-2-deoxy-β-D-glucopyranoside (1) was concisely synthesized in convergent synthesis with 48.0% overall yield. The structure of saponin 1 was confirmed by 1 H NMR, 13 C NMR and mass spectra.

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First Synthesis of a Bidesmosidic Triterpene Saponin by a Highly Efficient Procedure

Cited by 87 publications

References 12 publications

Synthesis and antitumor activities of glucan derivatives

Synthesis and antitumor activities of glucan derivatives

Synthesis and Hemolytic Activity of Some Hederagenin Diglycosides

Synthesis of an Ursolic Acid Saponin with N‐Acetylglucosamine‐containing Trisaccharide Residue

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