Acetylcholinesterase and Butyrylcholinesterase Inhibitory Activities ofβ-Carboline and Quinoline Alkaloids Derivatives from the Plants of GenusPeganum

Abstract

It was reported that the main chemical constituents in plants of genus Peganum were a serial ofβ-carboline and quinoline alkaloids. These alkaloids were quantitatively assessed for selective inhibitory activities on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) byin vitroEllman method. The results indicated that harmane was the most potent selective AChE inhibitor with an IC50of 7.11 ± 2.00 μM and AChE selectivity index (SI, IC50of BChE/IC50of AChE) of 10.82. Vasicine was the most potent BChE inhibitor with feature of dual AChE/BChE inhibitory activity, with an IC50versus AChE/BChE of 13.68 ± 1.25/2.60 ± 1.47 μM and AChE SI of 0.19. By analyzing and comparing the IC50and SI of those chemicals, it was indicated that theβ-carboline alkaloids displayed more potent AChE inhibition but less BChE inhibition than quinoline alkaloids. The substituent at the C7 position of theβ-carboline alkaloids and C3 and C9 positions of quinoline alkaloids played a critical role in AChE or BChE inhibition. The potent inhibition suggested that those alkaloids may be used as candidates for treatment of Alzheimer’s disease. The analysis of the quantitative structure-activity relationship of those compounds investigated might provide guidance for the design and synthesis of AChE and BChE inhibitors.