Medicinal foodstuffs. X. Structures of new triterpene glycosides, gymnemosides-c, -d, -e, and -f, from the leaves of Gymnema sylvestre R. Br.: influence of gymnema glycosides on glucose uptake in rat small intestinal fragments.
Following the characterization of gymnemosides-a and -b, new triterpene glycosides, gymnemosides-c, -d, -e, and -f, were isolated from the leaves of Gymnema (G.) sylvestre R. BR. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence as follows: 21-O-benzoyl-28-O-acetylgymnemagenin 3-O-beta-D-glucopyranosiduronic acid (gymnemoside-c), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] gymnestrogenin (gymnemoside-d), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D- glucopyranosyl]-28-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 23-hydroxylongispinogenin (gymnemoside-e), 23-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]-28-O-[beta-O-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta,16 beta,23,28-tetrahydroxyolean-18-ene (gymnemoside-f). The inhibitory effects of gymnemosides-c, -d, -e, and -f and principal triterpene glycosides from G. sylvestre on glucose uptake in rat small intestinal fragments were examined, and gymnemic acids II, III, and IV, gymnemasaponin V, and gymnemoside-f were found to exhibit the inhibitory activity.
Yoshikawa
M
M
Kyoto Pharmaceutical University, Japan.
Murakami
T
T
Matsuda
H
H
D000818:Animals; D002240:Carbohydrate Sequence; D005947:Glucose / Q000378:metabolism*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000187:drug effects* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D051381:Rats; D012503:Saponins / Q000302:isolation & purification; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
D006027:Glycosides; D010936:Plant Extracts; D012503:Saponins; D014315:Triterpenes; C007898:gymnemic acid; D005947:Glucose