Effect of Flavonoids on α-Glucosidase and β-Fructosidase from Yeast

抄録

The influence of 16 flavonoids on yeast α-glucosidase and β-fructosidase was investigated. Either p-nitrophenyl-α-D-glucopyranoside or maltose was used as substrate for α-glucosidase, and sucrose for β-fructosidase. Quercetin, myricetin, fisetin, and quercitrin strongly inhibited α-glucosidase at 0.1 mM. The concentrations which gave 50% inhibition were 4, 8, 8, 20, and 20 μM for myricetin, quercetin, fisetin, kaempferol, and quercitrin, respectively. The mode of inhibition was found to be mixed type, close to non-competitive type with quercetin and quercitrin. Fisetin, naringenin, and morin showed mixed type inhibition. Albumin from bovine serum slightly affected the anti-a-glucosidase activity of quercetin. The flavonoids tested exhibited little effect on β-fructosidase activity at 0.1 mM.