Vasoreactivity and mechanistic insights through molecular docking of rare antipodal sesquiterpene alcohol from Chrysopogon zizanioides L. Roberty essential oil

Vetiver ( Chrysopogon zizanioides ) contained structurally diverse bicyclic to tetracyclic sesquiterpenoids. However, the reported crystal structures from this plant remain enigmatic. The root parts are the important components in the Siddha system of medicine. The paste prepared in an aqueous medium is well documented in lowering the body temperature. We aim to investigate the biological potential as a vasorelaxation agent and crystal structure of oxygenated sesquiterpene from roots of the C. zizanioides . This study identified an elusive crystal structure using CD, FT-IR, NMR, MS, and X-ray diffraction methods. In addition, ex-vivo vasorelaxation behavior in the rat superior mesenteric artery has been studied. The Flack parameter confirmed the absolute configuration of khusinol, which showed concentration-dependent vasorelaxation. As revealed in docking experiments, the hydrogen bond and the binding energy are the two major factors for the proposed activity of the khusinol. We also recorded moderate anti-neuroinflammatory effects of khusinol against BV2 cells. The present work provides insights into the concentration-dependent vasorelaxation of crystalline khusinol in a rodent vascular model. Importantly, the vetiver based molecule has been identified as a major lead in developing plant-derived cardiovascular disease agents. • Chrysopogon zizanioides roots were subjected for bioactivity evaluation. • X-ray structure of rare antipodal sesquiterpene alcohol was deduced. • Flack (Paterson) parameter revealed the absolute stereochemistry as khusinol. • Khusinol showed concentration-dependent vasorelaxation in rat mesenteric artery. • Khusinol does not exhibit cytotoxicity up to 30 µM concentration.