Baruah Prayasee, Rohman Mostofa Ataur, Yesylevskyy Semen O, Mitra Sivaprasad
Centre for Advanced Studies in Chemistry, North-Eastern Hill University, Shillong - 793 022, India.
Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, Prospect Nauky 46, 03028 Kyiv, Ukraine.
Bioimpacts. 2019;9(2):79-88. doi: 10.15171/bi.2019.11. Epub 2019 Mar 8.
Documentation on the potency of chromones as acetylcholinesterase (AChE) antagonists has paved the way for the design and usage of new chromone analogues as inhibitors of AChE modelled on the hypothesis based on cholinergic pathway of Alzheimer's disease (AD). Here, 2 minimally substituted chromones, namely 3-cyanochromone (CyC) and 7-amino-3- methylchromone (AMC), were checked for their AChE inhibition efficacies and plasma protein modulation. Colorimetric enzymatic assay as well as fluorescence measurements were performed for obtaining the experimental results, which were further corroborated by molecular docking and simulation studies. The investigated systems exhibited strong inhibition activities against AChE, with CyC (IC= 85.12 ± 6.70 nM) acting as better inhibitor than AMC (IC = 103.09 ± 11.90 nM) and both having IC50 values in the range of FDA approved cholinergic drug Donepezil (IC = 74.13 ± 8.30 nM). Non-competitive inhibition was observed in both the cases with the inhibitors binding near the peripheral anionic site (PAS) of the enzyme. Having one planar nitrile group in CyC as compared to sp3 hybridised substituents in AMC facilitated stacking interactions in the former, accounting for its higher inhibitory efficacy. A significant decrease in the inhibition potency of CyC (32%) was noted in comparison with AMC (5%) when the experiments were performed in presence of human serum albumin (HSA) instead of pure aqueous buffer. This comparative study affirms the importance of meticulous substitution in the chromone scaffold to promote maximum inhibition potency, while considering their usage as AD drugs.
关于色酮作为乙酰胆碱酯酶(AChE)拮抗剂效力的文献,为基于阿尔茨海默病(AD)胆碱能途径假说设计和使用新型色酮类似物作为AChE抑制剂铺平了道路。在此,检测了2种最小取代的色酮,即3-氰基色酮(CyC)和7-氨基-3-甲基色酮(AMC)对AChE的抑制效力以及对血浆蛋白的调节作用。进行了比色酶法测定以及荧光测量以获得实验结果,分子对接和模拟研究进一步证实了这些结果。所研究的体系对AChE表现出强烈的抑制活性,其中CyC(IC = 85.12±6.70 nM)比AMC(IC = 103.09±11.90 nM)是更好的抑制剂,且两者的IC50值都在FDA批准的胆碱能药物多奈哌齐(IC = 74.13±8.30 nM)范围内。在这两种情况下均观察到非竞争性抑制,抑制剂在酶的外周阴离子位点(PAS)附近结合。与AMC中sp3杂化取代基相比,CyC中有一个平面腈基,这有利于前者的堆积相互作用,这解释了其更高的抑制效力。当实验在人血清白蛋白(HSA)而非纯水性缓冲液存在下进行时,与AMC(约5%)相比,CyC的抑制效力显著降低(约32%)。这项比较研究证实了在色酮支架中进行精细取代以提高最大抑制效力的重要性,同时考虑将它们用作AD药物。