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Yeast and mammalian alpha-glucosidase inhibitory constituents from Himalayan rhubarb Rheum emodi Wall.ex Meisson.
- Source :
-
Bioorganic & medicinal chemistry letters [Bioorg Med Chem Lett] 2004 Jul 16; Vol. 14 (14), pp. 3841-5. - Publication Year :
- 2004
-
Abstract
- The methanolic extract of rhizome of Himalayan rhubarb Rheum emodi displayed mild yeast as well as mammalian intestinal alpha-glucosidase inhibitory activity. However, further fractionation of active extract led to the isolation of several potent molecules in excellent yields, displaying varying degrees of inhibition on two test models of alpha-glucosidase. Rhapontigenin, desoxyrhapontigenin, chrysophanol-8-O-beta-d-glucopyranoside, torachrysone-8-O-beta-d-glucopyranoside displayed potent yeast alpha-glucosidase inhibition. However chrysophanol-8-O-beta-d-glucopyranoside, desoxyrhaponticin and torachrysone-8-O-beta-d-glucopyranoside displayed potent to moderate mammalian alpha-glucosidase inhibitory activity. Other compounds displayed mild activity on both the tests. Except desoxyrhapontigenin and rhapontigenin that increased Vmax, other compounds including crude extract decreased the Vmax significantly (p<0.02) in yeast alpha-glucosidase test. Further kinetic analysis on mammalian alpha-glucosidase inhibition showed that chrysophanol-8-O-beta-d-glucopyranoside, desoxyrhaponticin and torachrysone-8-O-beta-d-glucopyranoside may be classified as mixed-noncompetitive inhibitors. However, desoxyrhapontigenin and rhapontigenin may be classified as modulators of enzyme activity. Presence and position of glycoside moiety in compounds appear important for better inhibition of mammalian alpha-glucosidase. This is the first report assigning particularly, mammalian intestinal alpha-glucosidase inhibitory activity to these compounds. Chrysophanol-8-O-beta-d-glucopyranoside, desoxyrhaponticin, desoxyrhapontigenin and rhapontigenin have been isolated in substantial yields from R. emodi for the first time. Therefore, these compounds may have value in the treatment and prevention of hyperglycemia associated diabetes mellitus.
- Subjects :
- Animals
Binding, Competitive
Diabetes Mellitus drug therapy
Diabetes Mellitus prevention & control
Enzyme Inhibitors isolation & purification
Enzyme Inhibitors therapeutic use
Hyperglycemia drug therapy
Hyperglycemia prevention & control
Intestinal Mucosa metabolism
Kinetics
Plant Extracts chemistry
Plant Extracts pharmacology
Rats
Stilbenes chemistry
Stilbenes pharmacology
Yeasts
alpha-Glucosidases isolation & purification
alpha-Glucosidases metabolism
Enzyme Inhibitors pharmacology
Glycoside Hydrolase Inhibitors
Rheum chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 0960-894X
- Volume :
- 14
- Issue :
- 14
- Database :
- MEDLINE
- Journal :
- Bioorganic & medicinal chemistry letters
- Publication Type :
- Academic Journal
- Accession number :
- 15203173
- Full Text :
- https://doi.org/10.1016/j.bmcl.2004.04.062