Volatile chemical constituents of three Ocimum species (Lamiaceae) from Papua New Guinea (SPJNS)

Fresh aerial parts of three species of basil, Ocimum basilicum, O. tacilium and O. canum were subjected to exhaustive hydrodistillation to afford pale yellow coloured oils in 1.0, 0.7 and 0.01 percent yields respectively. Detailed chemical evaluation by GC and GC/MS revealed O. basilicum to be composed of a total of eleven components representing 100 percent of the total oil composition. Neral (36.1 %) and geranial (44.5 %) were found to be the major components. Ocimum tacilium was found to be composed of five components representing 99.8 % of the total oil composition with estragole (96.6 %) being the major component. Five components were observed in O. canum, representing 72.3 percent of the total oil composition with eugenol (35.3 %) and linalool (27.2 %) as the major components. The high citral (neral + geranial) content in O. basilicum suggests that it belong to the citral chemotype while O. tacilium belong to the estragole chemotype and O. canum belong to the eugenol chemotype.