Flavonol Caffeoylglycosides as alpha-Glucosidase Inhibitors from Spiraea cantoniensis Flower.
In the screening experiments for rat intestinal alpha-glucosidase inhibitors in 218 plants cultivated in the Japanese temperate region, potent maltase-inhibiting activity was found in the extract of flowers of Spiraea cantoniensis. The enzyme assay guided fractionation of the extract led to the isolation of three flavonol caffeoylglycosides, quercetin 3- O-(6- O-caffeoyl)-beta-galactoside ( 1), kaempferol 3- O-(6- O-caffeoyl)-beta-galactoside ( 2), and kaempferol 3- O-(6- O-caffeoyl)-beta-glucoside ( 3), as rat intestinal maltase inhibitors. This is the first report on the alpha-glucosidase-inhibitory activity of those flavonol caffeoylglycosides. Comparison in the activity of the isolates indicated the importance of caffeoyl substructures in the molecule for the alpha-glucosidase-inhibiting activity. The relatively high contents of the active isolates in the plant suggest that S. cantoniensis could be physiologically useful for treatment of diabetes.
Yoshida
Kaori
K
Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
Hishida
Atsuyuki
A
Iida
Osamu
O
Hosokawa
Keizo
K
Kawabata
Jun
J
D000818:Animals; D002109:Caffeic Acids / Q000737:chemistry / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D044948:Flavonols / Q000494:pharmacology*; D035264:Flowers / Q000737:chemistry*; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology; D007422:Intestines / Q000201:enzymology; D051381:Rats; D031992:Spiraea / Q000737:chemistry*; D013393:Sucrase / Q000037:antagonists & inhibitors
D002109:Caffeic Acids; D004791:Enzyme Inhibitors; D044948:Flavonols; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides; D013393:Sucrase