Analysis of Volatile Constituents in Curcuma Species, viz. C. aeruginosa , C. zedoaria , and C. longa , from Nepal.

The genus Curcuma , composed of 93 species mainly originating from Asia, Australia, and South America, has been used for medicinal purposes, aromatic, and nutritional values as well as cosmetic. It plays a vital role in flavoring and coloring as well as exhibiting therapeutic agents against different diseases. Nepalese farmers are unaware of the essential oil compositions of Curcuma species, viz. C. aeruginosa , C. zedoaria , and C. longa . The investigation of these three essential oils provides insight into their potential as cash crops and earns a reasonable return from their production. The essential oils were obtained from the rhizomes of each plant by hydrodistillation and subjected to Gas Chromatography/Mass Spectrometry (GC-MS) analysis to identify its volatile chemical constituents as well as chiral GC-MS to identify the enantiomeric distribution of chiral terpenoids. The order of extraction yields were C. longa (0.89%) > C. zedoaria (0.74%) > C. aeruginosa (0.37%). In total, the presence of 65, 98, and 84 compounds were identified in C. longa , C. zedoaria , and C. aeruginosa , representing 95.82%, 81.55%, and 92.59% of the total oil, respectively. The most abundant compounds in C. longa essential oils were ar -turmerone (25.5%), α-turmerone (24.4%), β-turmerone (14.0%), terpinolene (7.2%), β-sesquiphellandrene (5.1%), α-zingiberene (4.8%), β-caryophyllene (2.9%), ar -curcumene (1.6%) and 1,8-cineole (1.3%). The most dominant compounds in C. zedoaria were curzerenone (21.5%), 1,8-cineole (19.6%), curzerene (6.2%), trans -β-Elemene (5.1%), camphor (2.6%), and germacrone (2.3%). The major components in C. aeruginosa were curzerenone (59.6%), germacrone (5.3%), curzerene (4.7%), camphor (3.6%), trans -β-Elemene (2.6%), and β-eudesmol (1.6%). C. zedoaria , and C. aeruginosa essential oil from Nepal for the very first time. This study reports for the first time chiral terpenoids from C. aeruginosa , C. zedoaria , and C. longa essential oil. A chemical blueprint of these essential oils could also be used as a tool for identification and quality assessment.