Chemical diversity in curry leaf (Murraya koenigii) essential oils

Wild and cultivated Murraya koenigii leaf essential oils collected from ten Indian locations were investigated for their chemical diversity. The essential oil yields ranged from 1.2–2.5 ml/kg biomass. GC and GC-MS analyses revealed ninety compounds, constituting 93.8–99.9% of the essential oils. The highest concentrations of α-pinene (55.7%) and β-pinene (10.6%) were found in the essential oil of wild plants. α-Pinene (13.5–35.7%) and/or β-phellandrene (14.7–50.2%) were the dominant essential oil constituents of seven locations. (E)-Caryophyllene (26.5%, 31.5%) and α-selinene (9.5%, 10.4%) were the principal essential oil components of two locations. The odour profiles of the essential oils were distinctly different. Tetradecanoic acid, hexadecanoic acid, piperitone, cada-1,4-diene,1,10-di-epi-cubenol, γ-eudesmol, α-muurolol, (Z,E)-farnesol and (Z,Z)-farnesol are identified for the first time in curry leaf essential oil. The chemical diversity of the oils offers opportunity to flavourists to choose curry leaves and essential oils with preferential flavour composition.