Natural curcuminoids exhibit alpha-glucosidase inhibitory activity. - GreenMedInfo Summary
Alpha-glucosidase inhibition of natural curcuminoids and curcumin analogs.
Eur J Med Chem. 2006 Feb;41(2):213-8. Epub 2006 Jan 4. PMID: 16387392
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
Natural curcumin (1), demethoxycurcumin (2) and bisdemethoxycurcumin (3) isolated from Curcuma longa (turmeric), and synthetic curcumin analogs (A(1-7), B(1-7), C(1-6) and D(1-7)) were evaluated in vitro for the alpha-glucosidase inhibitory activity via UV and circular dichroism (CD) spectroscopy. The results indicated that natural curcuminoid compound 3 showed a remarkable inhibitory effect with IC(50) of 23.0 microM, and the synthetic compounds A(2), B(2), C(2) and D(2) showed potent inhibitory effects with IC(50) of 2.8, 2.6, 1.6 and 8.2 microM, respectively. Kinetic study exhibited that the mechanism of alpha-glucosidase inhibition of both 3 and C(2) was non-competitive. The structure activity relationship revealed that the ortho dihydroxyl groups could form a more tight interaction with alpha-glucosidase to exert more potential inhibitory activities.