Extract of Touchi containing an alpha-glucosidase inhibitor

摘要

An alpha-glucosidase inhibitor is described. It is comprised of an extract of Touchi selected from the group consisting of an extract of Touchi extracted with alcohol, an extract of Touchi extracted with a mixture of water and alcohol in a water to alcohol ratio of 1:5 to 5:1, and an extract of Touchi extracted with water at 100° C. to 140° C. The components in the extract which have a molecular weight of at least 3000 as determined by means of gel filtration or membrane filtration are at most 20% by weight and wherein the extract inhibits alpha-glucosidase at least 90.4%.