Alpha-glucosidase inhibition of natural curcuminoids and curcumin analogs.
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.
Du
Zhi-yun
ZY
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
Liu
Rong-rong
RR
Shao
Wei-yan
WY
Mao
Xue-pu
XP
Ma
Lin
L
Gu
Lian-quan
LQ
Huang
Zhi-shu
ZS
Chan
Albert S C
AS
D000818:Animals; D030024:Curcuma / Q000737:chemistry*; D003474:Curcumin / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000302:isolation & purification / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D065089:Glycoside Hydrolase Inhibitors; D020128:Inhibitory Concentration 50; D007700:Kinetics; D013329:Structure-Activity Relationship
D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D003474:Curcumin