TLC/GC-FID Analysis and Antioxidant Activity of Melicope madagascariensis (Baker) T.G. Hartley (Rutaceae) Essential Oil from Madagascar East Coast Rainforest

The aim of the present study was to evaluate the chemical composition and antioxidant activity of Melicope madagascariensis essential oil from Madagascar East Coast Rainforest. Essential oil from the leaves of this plant species was extracted by hydro-distillation and analyzed by TLC and GC-FID. The extraction revealed a yield is of 0.4% for a mass of 290 g of fresh leaves. Having a bland, pungent taste, the oil has a green-black color, a slightly unpleasant odor with a clear mobile consistency. Its density is 0.8765 and refractive index 1.4956 at 20 °C and is dextrorotatory (+0.1°) at 24 °C for its rotational power. The results of GC/FID analysis revealed that the essential oil contains (Z)-β-ocimene (12.7%) and (E)-β-ocimene (25.7%) as major compounds. The preparative TLC fractionation (using DPPH radical as revelator) and GC-FID analysis of the essential oil revealed the presence of compounds of the sesquiterpene family namely trans-nerolidol (4.32%), phenylpropanoid like methyl eugenol (5.9%), terpene oxide like caryophyllene oxide (3.66%), cinnamic esters like cinnamyl acetate (4.79%) and monoterpene alcohol like linalol (2.81%). The study on M. madagascariensis essential oil is herein reported for the first time. Further studies including cytotoxicity assay in order to evaluate the selectivity/therapeutic index of this essential oil are needed before developing it as novel antioxidant drug.