Novel piperazine–triazole hybrids as PTP1B and alpha-amylase inhibitors: synthesis, biological evaluation and computational validation through network pharmacology, molecular docking, MD simulations, DFT and MMPBSA analysis

Abstract

The inhibition of α-amylase and PTP1B is essential for controlling hyperglycemia and improving insulin signaling. In this study, a series of piperazine conjugates were synthesized in 61–78% yields. All compounds were biologically screened against α-amylase to assess their anti-diabetic potential. Among these, compounds with Cl and OMe substitutions showed exceptional enzyme inhibition with IC₅₀ values of 2.39 ± 0.41 µM and 2.97 ± 0.31 µM, respectively, higher than standard acarbose (10.30 ± 0.20 µM). Further network pharmacology study was conducted, which spotted PTP1B as an important target to improve insulin signaling. Molecular docking analysis of potent compounds was performed to evaluate interactions of inhibitors with target receptors (PTP1B & α-amylase). Both compounds validated the in vitro protocols by showing excellent binding affinities −10.5 kcal mol⁻¹ and −9.7 kcal mol⁻¹ against α-amylase, surpassing standard acarbose (−8.1 kcal mol⁻¹). Likewise, both of them exhibited a similar binding pattern with binding affinities of −8.0 kcal mol⁻¹ & −7.8 kcal mol⁻¹ against PTP1B, even better than the reference acarbose (−7.4 kcal mol⁻¹). DFT studies were carried out to determine electronic properties, which were corroborated through NCI analysis. Furthermore, 500 ns MD simulation, binding free energy calculations, PCA, DCCM and FEL analysis were carried out to evaluate thermodynamic stability.