Essential oil composition of fourOcimumspp. from the Peninsular India

Compositional characteristics of the essential oils of four Ocimum spp., namely Ocimum adscendens Willd., Ocimum gratissimum L., Ocimum tenuiflorum L. and Ocimum americanum L. were examined using GC-FID, GC-MS, and hierarchical cluster analyses from peninsular India. The essential oil content varied from 1.0% to 2.0% in different Ocimum spp. Altogether eighty-four constituents, corresponding to 89.9−96.5% of the total oil compositions were identified. Major constituents of O. adscendens oil were eugenol (47.6%), (E)-caryophyllene (15.7%) and β-elemene (11.3%). O. gratissimum oil was characterized by the presence of higher amounts of eugenol (52.9%), caryophyllene oxide (7.2%) and (Z)-β-ocimene (3.5%). Major constituents of O. tenuiflorum oil were methyl eugenol (50.9%), caryophyllene oxide (7.5%) and (E)-caryophyllene (5.5%). Moreover, the oil of O. americanum was dominated by camphor (41.8%), limonene (7.1%), α-pinene (6.2%), β-selinene (5.6%) and camphene (5.0%). To the best of our knowledge, a detailed essential oil profile of O. adscendens is being reported for the first time.