Experimental, quantum chemical spectroscopic investigation, topological, molecular docking/dynamics and biological assessment studies of 2,6-Dihydroxy-4-methyl quinoline

Abstract

The present work is a comprehensive investigation of the spectral, electronic structure, bonding, and reactivity of the 2,6-dihydroxy-4-methylquinoline (26DH4MQ) molecule through a wide range of experimental and quantum chemical spectroscopic calculations techniques, along with its applications as nonlinear optical materials and biological assessments. The study utilized density functional theory (DFT) and time-dependent density functional theory (TD-DFT) with the B3LYP method and the 6-311G++(d,p) basis set to analyze the structural and molecular properties of 26DH4MQ. The findings from UV–Vis, FT-IR, and FT-NMR spectroscopy show a strong agreement between the experimentally obtained vibrational frequencies and chemical shifts and those predicted by computational methods. Local reactivity descriptors, such as the dual descriptor, Fukui functions, and the molecular electrostatic potential (MEP) map, were used to identify the reactive regions of the molecule. Additionally, natural bond orbital (NBO) analysis provided insights into the charge transfer characteristics of 26DH4MQ, which helps to stabilize the molecular system. The study also revealed notable nonlinear optical (NLO) properties, with polarizability (18.52 × 10–24e.s.u) and first-order hyperpolarizability (2.26 × 10–30e.s.u) values that surpass those of standard organic compounds, suggesting significant potential for optoelectronic applications. The biological evaluation of 26DH4MQ assessed its drug-likeness, toxicity, enzyme inhibition, and ADME (Absorption, Distribution, Metabolism, and Excretion) parameters, highlighting its pharmaceutical potential. Furthermore, molecular docking and dynamics studies illustrated the compound's interactions with proteins, indicating its potential role as an insulin inhibitor.