Isolation, Characterization, and Single-Crystal X-ray Analysis of Lantabetulic Acid from Rhus alata: Insights into HSA and BSA Binding Interactions, with In-Silico Study

This study investigated the bioactive potential of Rhus alata, a plant known for its rich phytochemicals. A previously unreported compound was isolated from R. alata and characterized using various spectroscopic techniques (IR, UV, NMR, MS) and confirmed for the first time by X-ray crystallography. In isolated compound 1, noncovalent interactions between H···H/H···H, C···C/C···C and O···H/H···O play a major role in its packing arrangement. This observation is consistent with the results of Hirshfeld surface analysis, which quantified these interactions as 14.2%, 84.6%, and 1.2%, respectively. The isolated compound was identified as lantabetulic acid (1) (3β,25-expoxy-3α-hydroxylup-20(29)-en-28-oic acid). To understand its potential biological interactions, the binding affinity of lantabetulic acid to biomolecules such as bovine serum albumin (BSA), and human serum albumin (HSA), was assessed. The results showed significant binding efficacy, indicating potential interactions with these molecules. Furthermore, the DPPH assay demonstrated the potent antioxidant activity of this compound. We used in silico molecular docking to clarify the binding affinity between lantabetulic acid and a particular receptor. Furthermore, molecular dynamic simulation studies also explored the binding interaction. As well, MM/GBSA calculations corroborate the simulation results and the stability of the complex. Docking and dynamics studies revealed promising binding scores, suggesting further investigation into their potential therapeutic applications. Geometric parameters and the absorption spectrum of compound 1 were also determined using the DFT approach and compared with experimental findings.