Essential oil profiles of different parts of East Indian lemongrass {Cymbopogon flexuosus (Nees ex Steud.) Wats.}

Abstract

Different parts of Cymbopogon flexuosus var. Krishna, namely leaf lamina, leaf sheath, inflorescence stem, spikelet, root, rhizome and root + rhizome yielded 1.7%, 1.3%, 0.25%, 0.6%, 0.05%, 0.3% and 0.2% essential oils, respectively on a fresh weight basis. Gas chromatography–flame ionization detector (GC–FID) and GC–mass spectrometry (GC–MS) analyses showed seventy-three components constituting 93.5–99.7% of these oils. Leaf lamina oil was richer in isopulegol (1.9%), neral (34.8%) and citral (83.0%); leaf sheath oil in β-caryophyllene (1.5%) and caryophylleneoxide (1.9%); inflorescence stem oil in 6-methyl heptenone (3.1%), terpinolene (1.1%) and geranial (48.9%); spikelet oil in sabinene (1.5%), γ-terpinene (1.3%), geraniol (12.1%), geranyl acetate (8.3%) and (E)-cadina-1(2),4-diene (1.9%); root oil in terpinen-4-ol (9.0%), δ-elemene (6.6%), β-longipinene (2.7%), γ-elemene (2.4%), δ-cadinene (2.2%) and bulnesol (10.8%); rhizome oil in elemol (42.3%), eudesm-3-en-7-ol (29.5%) and α-bisabolone oxide A (9.1%); and root + rhizome oil in eudesm-11-en-4α-ol (9.6%) and epi-α-eudesmol (6.1%). Currently, leaf lamina oil is commercially produced. This investigation has revealed that leaf sheaths (76.2%) and inflorescence stems (80.5%) yielded citral-rich oils. Elemol, which finds application in fragrances with potential use in botanical pesticides, can be isolated from rhizome oil.