Changes in the essential oil content and chemical compositions of echinophora platyloba dc. during three different growth and developmental stages

Echinophora platyloba is a valuable essential oil bearing plant. The variation in the quantity and quality of the essential oil of wild populations of E. platyloba extracted by hydro distillation was studied during different growth and developmental stages. The content of essential oils (w/w %) were 0.7, 0.5, and 0.2 % in rosette, floral budding, and full flowering stages, respectively. The essential oils were analyzed by GC and GC-MS. Total of 41, 62, and 56 components were identified and quantified in the above mentioned stages, respectively. The oil content showed remarkable increase at rosette stage. The proportion of (Z)-β-Ocimene, as a major component at rosette, drastically decreased in floral budding and then slightly increased at full flowering stage. In contrast, (E)- β-ocimene was not detected at the rosette stage but was the major component at the subsequent harvest time and then decreased at full flowering stage. Moreover, monoterpene hydrocarbons were the main group of compounds in the rosette (71.6 %), floral budding (64.8 %), and full flowering stage (69.6 %). © 2009 Taylor & Francis Group, LLC.