Computational and experimental validation of free radical scavenging properties of high-performance thin-layer...

Phenyl myristate was isolated from Homalium nepalense, which is known for its therapeutic virtues in traditional medicine. However, the study of radical scavenging-capacity of phenyl myristate is limited by its relatively low abundance in medicinal plants. We have studied the isolation, structure-elucidation, and bioactivities of high-performance thin-layer chromatography validated phenyl myristate from hydroalcohol-extract of bark of H. nepalense. The chemical structure of phenyl myristate was elucidated by spectroscopic methods. The chromatography was performed on high-performance thin-layer chromatography aluminum plates coated with silica-gel 60 F₂₅₄ . Determination and quantitation of phenyl myristate were performed by densitometric-scanning at 254 nm (chloroform-methanol, 9:1, v/v; R_f 0.49). The method was validated according to International Council for Harmonisation guidelines in terms of linearity, specificity, sensitivity, accuracy, precision, robustness, and stability. Linearity-range of phenyl myristate was 100-500 ng/5 µL with correlation-coefficient r²  = 0.9997. Limits of detection and quantitation were 3.35 and 10.17 ng, respectively. Phenyl myristate showed significant free-radical-scavenging activities in 2,2-diphenyl-1-picrylhydrazyl, oxygen-radical-absorbance-capacity, and ex vivo cell-based-antioxidant-protection-in-erythrocytes assays. Molecular-docking approach of phenyl myristate showed effective binding at active sites of human serum albumin (HSA) with the lowest binding energy (-8.4 kcal/mol) that was comparable with ascorbic acid (-5.0 kcal/mol). These studies provide mechanistic insight into the potential free radical scavenging activities of phenyl myristate.