Synthesis of Curcumin Analogues Monoketone from Cinnamaldehyde and their Inhibition Assay against Alpha Glucosidase Enzyme
The synthesis of curcumin analogues monoketone as target compounds from cinnamaldehyde and inhibition assay against alpha glucosidase enzyme had been performed. The stepwise of synthesis was performed by aldol condensation Claisen Schmidt reaction andused ketones variation to give curcumin analogues monoketone. The antidiabetic activity of curcumin analogues was carried out by inhibition test against alpha glucosidase enzyme isolated from rotten rice (Oryza sativa) The first step of synthesis was started by reacting cinnamaldehyde and monoketones such as acetone (curcumin analog A (1E,3E,6E,8E) 1,9 diphenyl 1,3,6,8 nanotetraen 5 one] cyclopentanone (curcumin analog B (2E,5E) 2,5 bis (E) 3 phenylallylidene) cyclopentanone] and cyclohexanone (curcumin analog C (2E,6E) 2,6 bis (E) 3 phenylallylidene] cyclohexanone] in ethanol as solvent. The synthesis was carried out in base condition (KOH) by stirring at 52 degC for 50 minutes. The structures of all products were identified by using FTIR, direct inlet MS, 1H and 13C NMR. Futhermore, the activity of curcumin analogues was tested against with alpha glucosidase enzyme inhibition. The results show that the curcumin analogues (A C) were yielded in 85.57; 72.15; and 82.97% respectively as yellow solid. The melting point of curcuminanalogues (A C) were at 116.60 122.40; 196.20 200.10; and 142.30 148.10 degC, respectively. The inhibition of alpha glucosidase enzyme indicated that the curcumin analog B was potential to inhibit alpha glucosidase enzyme with the highest activity by giving inhibition percentage of about 70.71% at 2.5 mM.