Gas Chromatography-Mass Spectrometric (GC-MS) Analysis of Ethanolic Extract of the Peel of Dioscorea bulbifera Linn (Air Potatoe)

Abstract

The bioactive chemical compounds in the ethanolic extracts of the peel of Dioscorea bulbifera Linn, native to Nigeria was investigated and characterized using gas chromatography-mass spectrometric (GC-MS) analysis. The relatively high concentration of the phytochemicals in the peel of this tuber; saponin (32.28mg/g), terpenoid (22.90mg/g), cardiac glycoside (15.90mg/g), flavonoid (9.17mg/g), tannin (4.79mg/g) and phlobatannin (1.87mg/g), was the most attractive factors that triggered the present study. The GC-MS analysis of the ethanolic extract of the peel of D. bulbifera shows 4 prominent peaks as R-(-)-1,2-Propanediol (C₃H₈O₂) with retention time of 6.103min and the highest peak area of 86.05%; 1-Methylhexylhydroperoxide (C₇H₁₆O₂) with retention time of 42.567min and peak area of 5.57%; Cis-3-hexenyllactate (C₉H₁₆O₃) with retention time of 45.395min and peak area of 5.01%; and Pyrrole (C₄H₅N) showed peak of 3.37% with retention time of 45.508min. Other less prominent peaks at other retention times included; 2-Nitro-Dimethylnitromethane (C₃H₇NO₂) with retention time of 37.355min, Ethylenimine (C₂H₅N) with retention time of 42.665min, N-Formyl-N-Methyl-formamide (C₃H₅NO₂) with retention time of 44.225min, and Guanidine (CH₅N₃) with retention 44.225min. This work which is the first-time report on the bioactive compounds in the organic crude extracts of Dioscorea bulbifera native to Nigeria, using the GC-MS, has however established the presence of quite number of chemical compounds in the peel of the tuber, to which their pharmacological activities could be attributed. The presence of these secondary metabolites in the peel of Dioscorea bulbifera, is hence, the major contributing factors behind its antimicrobial potential.

Keywords: GC-MS, Dioscorea bulbifera, antimicrobial properties, bioactive compounds, ethanolic extract