Yeast α-glucosidase inhibition by isoflavones from plants of Leguminosae as an in vitro alternative to acarbose.
In the course of searching for new classes of α-glucosidase inhibitors originated from natural resources, 11 kinds of isoflavones, i.e., medicarpin (1), formononetin (2), mucronulatol (3), (3R)-calussequinone (5), (3R)-5'-methoxyvestitol (6), tectorigenin (7), biochanin A (8), tuberosin (9), calycosin (10), daidzein (11), and genistein (12), as well as a flavone, liquritigenin (4), were isolated as active principles responsible for the yeast α-glucosidase inhibitory activity from two leguminous plant extracts, i.e., the heartwood extract of Dalbergia odorifera and the roots extract of Pueraria thunbergiana. Each components (1-12) demonstrated a significantly potent inhibition on yeast α-glucosidase in a dose dependent manner when the p-nitrophenyl-α-D-glucopyranoside was used as a substrate in vitro. The concentration required for 50% enzyme inhibition (IC50) were calculated as 2.93 mM (1), 0.51 mM (2), 3.52 mM (7) 0.35 mM (8), 3.52 mM (9), 0.85 mM (11), and 0.15 mM (12) when that of reference drug acarbose was evaluated as 9.11 mM, in vitro. However, isoflavone glycosides, i.e., puerarin (13), daidzin (14), formononetin-7-O-β-glucopyranoside (15), and genistin (16), exhibited a relatively poor inhibitory activity on yeast α-glucosidase as compared with the corresponding isoflavone (2, 11, 12), respectively.
Choi
Chun Whan
CW
Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea.
Choi
Yeon Hee
YH
Cha
Mi-Ran
MR
Yoo
Dae Seok
DS
Kim
Young Sup
YS
Yon
Gyu Hwan
GH
Hong
Kyung Sik
KS
Kim
Young Ho
YH
Ryu
Shi Yong
SY
D020909:Acarbose / Q000737:chemistry; D055808:Drug Discovery; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D007887:Fabaceae / Q000737:chemistry*; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000302:isolation & purification; D007529:Isoflavones / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D010936:Plant Extracts / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D007529:Isoflavones; D010936:Plant Extracts; D029701:Saccharomyces cerevisiae Proteins; D020909:Acarbose