Abstract: According to different acidity of free Flavonoids in Resina Draconis, different acidic lavonoids were extracted with the pH gradient extraction method from ethyl ether. Two compounds were isolated from weak acidicmixture. Weak acidic compounds showed higher activity in comparing to the crude powder of Guangxi Resina Draconis with 45.5% increase of IC₅₀. This provides a useful reference to the study of inhibitive activity of flavones for α-D-glucosidase enzyme.

Key words: free Flavonoids, α-D-glucosidase enzyme, Resina Draconis