Identification of the components of a non polar extract of the aerial parts of Dunalia spinosa by GC-MS

This communication reports the chemical composition of the light petroleum ether extract from the leaves and stems of Dunalia spinosa. The aerial part of D. spinosa was extracted using light petroleum ether, which on evaporation yielded a residue. This residue was subsequently fractioned using CC chromatography on silica gel with petroleum ether, petroleum ether-CH2Cl2 gradient, CH2Cl2 and CH2Cl2-MeOH gradient. The fractions were analyzed using GC and GC-MS. A total of 34 compounds were identified accounting for 56.59% of the extracted mass. The unidentified compounds were isomers of branched chain alkanes and alkenes for which there were no documented compounds matching their calculated RI's. The following compounds were identified: n-Alkanes (65.88%) from C-14 to C-21 as the primary components. 1-Alkenes (1.15%): 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-nonadecene. Aldehydes (1.29%): hexanal, nonanal and decanal. Monoterpenes (5.9%) sabinene, beta-pinene, p-cymene, limonene, 1,8-cineol and 1.8-trans-sabinene. Sesquiterpenes (0.17%), caryophyllene oxide. Diterpenes (1.64%): Phytol. In addition, various compounds of note were identified, specifically pythone (4.98%), 7-oxabicyclo [4.1.0] heptane (5.85%) and methyl hexadecanoate (5.57%). This methodology is appropriate for the identification of complex compound mixtures in discarded fractions as in many phytochemical studies, these fractions provide a more complete profile of secondary metabolites in the studied species.