Structural determination of an isolated vasodilatory molecule from Passiflora edulis Sims (Passifloraceae)

This study aimed to isolate and characterize a vasodilatory compound from Passiflora edulis Sims using bioassay-guided fractionation, chromatographic and spectroscopic techniques. The bioactive molecule was isolated from the ethyl acetate fraction using preparative thin-layer chromatography and structurally elucidated via spectroscopic methods (UV, 1D- and 2D NMR, MS). The vasodilatory activity of the isolate was investigated on isolated rat aorta. Thin Layer Chromatography revealed two principal compounds in the ethyl acetate fraction with retention factors (Rf) of 0.65 and 0.54. The compound with Rf 0.65 demonstrated significant vasorelaxant effects on norepinephrine-precontracted aorta with an EC50 of 3.64×10-5 M. Comparison of chemical shifts (δH) and spin-spin coupling constants (JHH) with literature data confirmed the identity of the isolate (D65) as 8-methylheptadecane. This discovery bridges traditional knowledge with modern pharmacological research, offering new perspectives for cardiovascular drug development from natural sources.