Chemical composition of essential oil of four flavouring plants used by the tribal people of Bandarban hill district in Bangladesh

Choto oinchin (Elsholtzia incisa Benth), boro oinchin (Plectranthus incanus Link), jhum bahor pata (Sesali daucifolium W & A) and jhongaju (Ocimum basilicumvar. purpurascens) are flavouring plant species widely grown in jhum by the tribal people of the Bandarban Hill District. Essential oil composition of these four species was analyzed by GC-MS analysis methods. Results showed that Sesali daucifolium contains 73 compounds of which dihydrocoumarin, 5,7, 8-trimethyl was the highest (27.51%), followed by d-camphene (19.83%), terpinolene (13.70%), and β-mycrene (6.52%). Plectranthus incanus contains 67 chemicals and copane is the major component (21.47%), followed by pipe r- tone oxide (21.18 %), fenchone (12.19%), 2-carane (6.30%). Essential oil of aerial parts of Elsholtzia incisa contains 47 compounds and the main component was phenol 2,3,5,6-teramethyl/ druenol (33.44%), followed by terpinolene (19.57%), O-cymene (9.74%), Z-ocimene (7.32%), Z-carene (5.10%), 4-Terpineol (2.89%), β-myreene (2.52%), L- phellandrene (2.50%), cis-Sabinenehydrate (2.09%) and caryophyllene (1.87%). Essential oil of aerial par ts of Ocimum basilicum var. purpurascenscontains 58 components and main component was methyl cinnamate 59.62 % followed by linalool (16.40%), tau-cadinol (4.37%), α-bergamotene (3.03 %), γ-muurolene (2.06%), sulfone- methyl styryl (1.68 %), and methyl chavicol (1.55%). Essential oil of Ocimum basilicum var. purpurascens contains highest percentage of me- thyl cinnamate, 59.62% in leaves and 64.34% in inflore scence.