Degree–based topological indices, NMR chemical shifts, chemical reactivity, molecular dynamics and DFT analysis of 1,4-Methanoazulene-9-methanol, Decahydro-4,8,8-trimethyl-, [1S-(1α,3aβ,4α,8aβ,9R)]

Abstract

This study aims to comprehensively analyze the structural, vibrational, and electrical characteristics of 11,4-Methanoazulene-9-methanol, decahydro-4,8,8-trimethyl-, [1S-(1α,3aβ,4α,8aβ,9R*)] (MMDT) with a focus on its potential as a therapeutic agent for liver cancer. The compound was isolated from Hybanthus enneaspermus using Soxhlet extraction, followed by Gas Chromatography-Mass Spectrometry (GC–MS) analysis. The structure optimization and vibrational frequency assignments were done using Density Functional Theory (DFT) method with the B3LYP/6–311++G (d, p) basis set. Natural Bond Orbital (NBO) analysis was conducted to explore intramolecular and intermolecular interactions, along with the first-order hyperpolarizability. Electronic properties such as the energy gap and molecular electrostatic potential (MEP), were calculated to anticipate reactive sites for electrophilic and nucleophilic attacks. This is crucial in understanding the compound's reactivity in biological systems. TD-DFT was employed to simulate UV–visible spectra and compared with experimental values. Additionally, the theoretical FTIR spectra were correlated with experimental data, with potential energy distribution (PED%) providing detailed vibrational mode analysis. HOMO and LUMO orbitals were evaluated in the gas phase, revealing key energy parameters. ¹H and ¹³C NMR chemical shifts have been properly assigned using the DFT for structural characterization. QSPR/QSAR analysis is made simpler by determining a few topological indices for the MMDT. This study provides a novel computational framework for MMDT paving the way for faster, cost-effective and the Molecular docking studies revealed stable interactions between MMDT and liver cancer-related receptors, with favourable binding energy values along with Ramachandran plot confirmed the stability of the protein-ligand complex could be a promising candidate for liver cancer treatment.