1Biotechnology and Molecular Genetics Laboratory, Department of Botany, University College of Science, Osmania University, Hyderabad-500 007, Telangana, India
2Plant Systematics, Biodiversity and Conservation Laboratory, Department of Botany, University College of Science, Saifabad, Osmania University, Hyderabad-500 004, Telangana, India
*Corresponding author e-mail: narendar.botany2011@gmail.com
The chemical composition of leaf essential oil from Gymnanthemum amygdalinum was analyzed for seasonal variation using GC and GC-MS methods. Leaves collected in summer, rainy, winter and spring seasons were used to obtain essential oils through hydrodistillation. The oil yield varied between 0.27% and 0.36%. A total of 36 compounds were identified, accounting for 74.91%, 83.37%, 97.87%, and 85.04% of the total oil composition during summer, rainy season, winter and spring, respectively. Throughout all seasons, sesquiterpene hydrocarbons were the predominant components, winter exhibiting the highest proportion at 28.46%. Across all seasons, β-pinene was the predominant monoterpene, peaking at 3.43% in winter. The main sesquiterpenes were β-caryophyllene and germacrene D, while the major oxygenated monoterpenes were borneol, dihydrocarveol, isobornyl acetate and β-thujone. Oxygenated sesquiterpenes like farnesol, τ-cadinol, β-bisabolol, and spathulenol were always found. With winter and spring recognized as the best harvesting times for bioactive terpenoids, the research underscores significant seasonal impacts on essential oil composition.
Gymnanthemum amygdalinum, essential oil, seasonal variation, GC-MS analysis, terpenoids and sesquiterpenes
