Structural, spectroscopic characterization, solvent effect, topological aspects, and biological investigation of abietane diterpene pisiferic acid

In recent decades, plant-based metabolites have gained prominence in the pharmaceutical and food industries. In this present investigation, pisiferic acid (PA) an abietane diterpene acid with a chemical formula of C 20 H 28 O 3, has been characterized using combined theoretical and experimental approaches to detail its spectroscopic, structural, topological, reactive site prediction, biological interactions, and solvent effects on its frontier molecular orbitals (FMO), electronic spectra, and molecular electrostatic potential (MEP) analysis. The optimized molecular structure comprises 53 bond distances and 101 bond angles. The vibrational wavenumbers revealed the characteristic peaks associated with hydroxyl, methine, carbonyl, methyl, and methylene groups. The HOMO-LUMO energy gap values are calculated at 5.3745 eV (Gas), 5.371 eV (Ethanol), 5.3699 eV (Water), 5.375 eV (Chloroform), and 5.3773 eV (Toluene). The electrophilic and nucleophilic reactive sites within the molecular structure were confirmed with the Mulliken charge distribution and molecular electrostatic potential (MEP) analysis. The topological finding reveals that the hydrogens H42 linked to carbon C18 in the meta position relative to the O3-H45 hydroxyl group and H27 in the CH 2 methylene group were highlighted in red, indicating increased electron density or localized electron regions. In ADMET prediction, pisiferic acid exhibits drug-likeness characteristics. In addition, the molecular docking against antiapoptotic proteins Bcl-2 and Bcl-xL with a binding affinity of −6.77 and −6.68 Kcal/mol, supporting its antiapoptotic characteristics. • The theoretical and experimental spectroscopic features of Pisiferic acid were investigated. • The solvent impact on electronic spectra and FMO was investigated. • The Mulliken and MEP analyses reveal electron-rich and electron-poor regions. • The ELF and LOL reveal the delocalized and localized regions. • The molecular docking confirms the antagonist characteristics towards antiapoptotic proteins.