Reduction of glycyrrhizic acid

Балтина, Л. А.; Serdyuk, N. G.; Васильева, Е. В.; Толстиков, Г. А.

doi:10.1007/bf02495229

Cited by 6 publications

(22 citation statements)

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“…13 The signals of the C(1 ") atoms in the 13C NMR spectra of glycosides 6d and 6e are present at 8 98.2 and 99.2 ppm. This was previously observed in the spectrum of triterpene 2,6-deoxy-a-L-arabino-hexopyranoside.…”

Section: -Deoxy-el-d-arabino-hexopyranosidesmentioning

confidence: 98%

Direct stereospecific synthesis of triterpene and steroid 2-deoxy-α-glycosides

1997

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6066Stereospccific synthesis of 2-deoxy-ct-glycosides of methyl glycyrrhetate, methyl deoxycholate, and cholesterol was performed by Nycosylation of the corresponding alcohols with glycal acetates in the presence of a cation-exchange resin (H § and LiBr.Key words: stereo-and regiospecific glycosylation, methyl glycyrrhetate, methyl deoxychoiate, cholesterol, glycal acetates, acidic catalysis, 2-deoxygtycosides.Recently 1-3 we reported the two-step synthesis of 2-deoxyhexopyranosides via stereospecific gtycosytation of triterpene alcohols with glycal acetates in the presence of iodine-containing activators, such as N2iodo -succinimide (NIS) and di(sym-collydine)iodonium perchlorate (IDCP). The reaction of glycals with alcohols under the conditions of acidic catalysis, 4 which was used for preparation of 2-deox2,'glycosides, allows one to exclude the steps of 2-deoxy-2-iodoglycoside synthesis and deiodination. To synthesize triterpene 2-deoxyglycosides, we used sulfonic acid cationites and LiBr as activators.Under the conditions mentioned, 5 glycyrrhetinic acid methyl ester (la) was glycosylated with hexa-Oacetytlactal (2) and hexa-O-acetylmaltal (3), deoxycholic acid methyl ester (lb) was glycosylated with 3,4,6-tri-O-acetyl-D-glucaI (4) and 3,4-di-O-acetyl-Lrhamnal (5), and cholesterol (lc) was gtycosylated with 3,4-di-O-acetyl-L-rhamnal (5).Glycosylation resulted in 2-deoxy-a-glycosides of triterpene (6a,b) (54 and 58% yields) and steroid (6e, The structure of compounds 6 and 7 was established by NMR spectroscopy and also by comparison of the retention factors and physicochemicat characteristics of the compounds obtained with those of glycosides synthesized earlier using IDCP and NIS methods. The signals in the NMR spectra were assigned on the basis of fiterature data for aglycones 6-9 and carbohydrate moieties. 9-1l The 13C NMR spectra of the aglycone moieties of the glycosides synthesized were the same as

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Section: -Deoxy-el-d-arabino-hexopyranosidesmentioning

confidence: 98%

Direct stereospecific synthesis of triterpene and steroid 2-deoxy-α-glycosides

1997

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“…Protected amides of GL (44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56) were synthesized by the reaction of penta-O-acetyl GL trichloride (43) with amines R N H 2 with 52-90% yields [68,69]. Heterocyclic and aromatic amides (57)(58)(59)(60)(61)(62)(63)(64)(65)(66) were prepared by the condensation of GL with bioactive amines, quinolines, uracils and sulfanylamides using DCC [70][71][72].…”

Section: Synthesis Of Glycyrrhizic Acid Amidesmentioning

confidence: 99%

“…Structures of prepared esters were confirmed by spectral data and the preparation of penta-O-acetates [64]. Benzyl esters of GL and GLA were synthesized using PhCH 2 Br in the presence of phase-transfer catalysts and 2-methyl-2-propanol [65].…”

Section: Synthesis Of Glycyrrhizic Acid Estersmentioning

confidence: 99%

“…The full or selective esterification of hydroxyl groups of the carbohydrate part of GL, its salts or trimethyl ester (17) was carried out using chlorides of various aromatic acids in pyridine, pyridine -triethylamine or pyridine -tributylamine to form esters (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42) [66,67].…”

Section: Synthesis Of Glycyrrhizic Acid Estersmentioning

confidence: 99%

“…GL with 85-90% purity was produced from the commercial licorice extract by the extraction with acetone in the presence of mineral acids and the subsequent precipitation of glycoside as tri-and monopotassium salts [51,52]. Purified GL (92±2%) was produced from commercial monoammonium salt (75±2% purity) using 1.…”

Section: Isolation Of Glycyrrhizic Acid From Raw Materials and Its Stmentioning

confidence: 99%

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Chemical Modification of Glycyrrhizic Acid As A Route to New Bioactive Compounds for Medicine

Балтина

2003

CMC

219

158

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Glycyrrhizic Acid (GL) is the major bioactive triterpene glycoside of licorice root (Glycyrrhiza Radix) extracts possessing a wide range of pharmacological properties (anti-inflammatory, anti-ulcer, anti-allergic, anti-dote, anti-oxidant, anti-tumor, anti-viral etc.). Official sources of GL are Glycyrrhiza glabra L. and Gl. uralensis Fish. (Leguminosae). The content of GL in licorice root is 2-24% of the dry weight. GL is one of the leading natural compounds for clinical trials of chronic active viral hepatitis and HIV infections (preparation Stronger Neo-Minophagen C, SNMC), and its monoammonium salt (glycyram, tussilinar) is used as an anti-inflammatory and anti-allergic remedy. The synthetic transformations of GL on carboxyl and hydroxyl groups were carried out to produce new bioactive derivatives for medicine. GL esters were produced containing fragments of bioactive acids (4-nitrobenzoic, cinnamic, salycilic, acetylsalycilic, nicotinic, isonicotinic). Bioactive amides of GL were synthesized using chloroanhydride technique and N,N'-diciclohexylcarbodiimide (DCC) method. The synthesis of acylthioureids and semicarbazones was carried out via the reaction of triacylisothiocianate of penta-O-acetyl-GL with primary amines and hydrazines. The chain of transformations of trichloranhydride of penta-O-acetyl-GL was made with the introduction of diazoketone groups in the molecule. A new group of GL derivatives to be triterpene glycopeptides was prepared by the activated esters method (N-hydrohysuccinimide-DCC or N-hydroxybenzotriazol-DCC) using alkyl (methyl, ethyl, propyl, butyl, tert-butyl) or benzyl (4-nitrobenzyl) esters of amino acids. The glycyrrhizyl analogs of the known immunostimulator, N-acetyl-muramoyldipeptide (MDP), were synthesized using Reagent Woodward K. A series of ureids and carbamates of GL was synthesized containing 5-amino-5-desoxy-D-xylopyranose units. The synthesis of 4-nitro-4-desoxy-glycosides, modified analogs of GL, was carried out by the oxidative splitting of the carbohydrate part of GL with NaIO(4). Triterpene 2-desoxy-D-glycosides, analogs of GL, were prepared by the glycal method in the presence of iodine-containing promoters or sulfonic acid cation-exchange resin KU-2-8 (H+) and LiBr. New anti-inflammatory and anti-ulcer agents were found among GL derivatives such as esters, amides, ureids, carbamates, thioureids and glycopeptides. GL glycopeptides are of interest as immunomodulators. Some of the chemically modified GL derivatives (salts, amides, glycopeptides) were potent HIV-1 and HIV-2 inhibitors in vitro. Preparation niglizin (penta-O-nicotinate of GL) was studied clinically as an anti-inflammatory agent and is of interest for studies as hepatoprotector and HIV inhibitor.

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ChemInform Abstract: Reduction of Glycyrrhizic Acid.

et al. 1997

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Reduction of Glycyrrhizic Acid. -The reduction of the potassium salt of glycyrrhizic acid (I) with NaBH4 proceeds selectively at the carboxylic groups of the glycoside residue and at the C-11 carbonyl group of the aglycone moiety to form the compound (III). In contrast, the reduction of pure glycyrrhizic acid (IV) with LiAlH4 proceeds at all carboxylic groups and the carbonyl group. -(BALTINA, L. A.; SERDYUK, N. G.; VASIL'EVA, E. V.; TOLSTIKOV, G. A.; Izv.

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Reduction of glycyrrhizic acid

Abstract: The reduction of glycyrrhizic acid by NaBH 4 and LiAIH 4 was studied. The conditions for the selective reduction of the COOH groups of the carbohydrate chain and the C(I 1)=O group of aglycon were found.

Cited by 6 publications

References 1 publication

Direct stereospecific synthesis of triterpene and steroid 2-deoxy-α-glycosides

Direct stereospecific synthesis of triterpene and steroid 2-deoxy-α-glycosides

Chemical Modification of Glycyrrhizic Acid As A Route to New Bioactive Compounds for Medicine

ChemInform Abstract: Reduction of Glycyrrhizic Acid.

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