Comparative Cholinesterase, α-Glucosidase Inhibitory, Antioxidant, Molecular Docking, and Kinetic Studies on Potent Succinimide Derivatives.

Introduction: The current study was designed to synthesize derivatives of succinimide and compare their biological potency in anticholinesterase, alpha-glucosidase inhibition, and antioxidant assays.
Methods: In this research, two succinimide derivatives including ( S )-1-(2,5-dioxo-1-phenylpyrrolidin-3-yl) cyclohexanecarbaldehyde (Compound 1 ) and ( R )-2-(( S )-2,5-dioxo-1-phenylpyrrolidin-3-yl)-2-phenylpropanal (Compound 2 ) were synthesized using Michael addition. Both the compounds, ie, 1 and 2 were evaluated for in-vitro acetylcholinesterase (AChE), butyrylctcholinesterase (BChE), antioxidant, and α-glucosidase inhibitory potentials. Furthermore, molecular docking was performed using Molecular Operating Environment (MOE) to explore the binding mode of both the compounds against different enzymes. Lineweaver-Burk plots of enzyme inhibitions representing the reciprocal of initial enzyme velocity versus the reciprocal of substrate concentration in the presence of synthesized compounds and standard drugs were constructed using Michaelis-Menten kinetics.
Results: In AChE inhibitory assay, compounds 1 and 2 exhibited IC ₅₀ of 343.45 and 422.98 µM, respectively, against AChE enzyme. Similarly, both the compounds showed IC ₅₀ of 276.86 and 357.91 µM, respectively, against BChE enzyme. Compounds 1 and 2 displayed IC ₅₀ of 157.71 and 471.79 µM against α-glucosidase enzyme, respectively. In a similar pattern, compound 1 exhibited to be more potent as compared to compound 2 in all the three antioxidant assays. Compound 1 exhibited IC ₅₀ values of 297.98, 332.94, and 825.92 µM against DPPH, ABTS, and H ₂ O ₂ free radicals, respectively. Molecular docking showed a triple fold in the AChE and BChE activity for compound 1 compared with compound 2 . The compound 1 revealed good interaction against both the AChE and BChE enzymes which revealed the high potency of this compound compared to compound  2 .
Conclusion: Both succinimide derivatives exhibited considerable inhibitory activities against cholinesterases and α-glucosidase enzymes. Of these two, compound 1 revealed to be more potent against all the in-vitro targets which was supported by molecular docking with the lowest binding energies. Moreover, compound 1 also proved to have antiradical properties.
Competing Interests: The authors report no conflicts of interest in this work.
(© 2020 Ahmad et al.)