Transformations of Glycyrrhizic Acid: The Synthesis of 3-O-[β-6’-Desoxy-6’-amino-d- glucopyranosyl (1→2)-β-6”-Amino-D-glucopyranosido]-(3β,20β)-11-oxo-20-methoxy- carbonyl-18β-olean-12-en-3-ol

Antiviral Activity of Glycyrrhizic Acid Derivatives against SARS−Coronavirus

“…β-D-Glucopyranosyl-(1f2)-β-D-glucopyranoside 9 of GLA methyl ester was synthesized by the reduction of GA trimethyl ester (1 mmol) in aqueous MeOH (150 mL) with NaBH4 (2 g) at 20-22 °C for 8 h and recrystallized from EtOH as described previously: 17 Bis-(6′,6′′-diazide) 13 of GLA methyl ester was synthesized from 9 with 57% yield as described in: 17 [R] 20 D +42 °(c 0.02; MeOH), lit. : 17 [R] 20 D + 40°(c 0.02; dioxane).…”

“…16 The β-D-glucopyranosyl-(1f2)-β-D-glucopyranoside 9 of GLA methyl ester was synthesized by the reduction of GL trimethyl ester in aqueous MeOH with NaBH 4 at 20-22 °C, and its bis-6′,6′′-diazide (13) was formed as previously described. 17 Heterocyclic amides 10 and 11 of GL were prepared by the reaction of GL with 5-aminouracyl and 6-amino-2-thiouracyl in the presence of DCC in dimethylformamide-pyridine (DMF-Py) mixtures. 18 GL 30-methyl ester diacyl hydrizide (12) was produced by the reaction of GL trimethyl ester with NH 2 NH 2 (85%) in MeOH under reflux with the yield of 77%.…”

“…Amino acid derivatives 2 − 8 of GL (glycopeptides) were synthesized by using N , N ‘-dicyclohexylcarbodiimide (DCC) and N -hydroxysuccinimide (HOSu) or DCC− N -hydroxybenzotriazole (HOBt) as previously reported. − The selective synthesis of compounds 2 and 3 containing two residues of S -benzyl- l -cysteine or glycyl- l -leucine in the carbohydrate part of the GL molecule was carried out by the activated ester method (DCC−HOSu) using S -benzyl- l -cysteine or glycyl- l -valine tert -butyl esters as hydrochlorides in tetrahydrofuran (THF) in the presence of Et 3 N. Glycopeptides 4 and 5 were prepared from GL and l -leucine tert -butyl or l -glutamic acid dibenzyl ester hydrochlorides by using DCC−HOBt in dioxane. , tert -Butyl ester groups were deblocked with CF 3 COOH, and benzyl ester groups were removed by catalytic hydrogenolysis over 10% Pd/C in 75% CH 3 COOH . The β- d -glucopyranosyl-(1→2)-β- d -glucopyranoside 9 of GLA methyl ester was synthesized by the reduction of GL trimethyl ester in aqueous MeOH with NaBH 4 at 20−22 °C, and its bis-6‘,6‘ ‘-diazide ( 13 ) was formed as previously described . Heterocyclic amides 10 and 11 of GL were prepared by the reaction of GL with 5-aminouracyl and 6-amino-2-thiouracyl in the presence of DCC in dimethylformamide−pyridine (DMF−Py) mixtures .…”

Antiinflammatory and antiulcer properties of 3-O-(β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside) derivatives of steroidal alcohols

“…Searching for new compounds possessing high antiinfiammatory and antiulcer activity, we have studied the pharmacological properties of two modified derivatives ofglycyrrhizic acid, representing 13-D-glucopyranosyl-(l--~ 2)-13-Dglucopyranosides of glycyrrhetic acid methyl ether (I) and 1813-olean-9(11)12(13)-dien-313-ol (II). Compounds I and II were synthesized as described in [8], by reducing glycyrrhizic acid with NaBH4 under various conditions.…”