Impact of Water Stress and Temperature on Metabolites and Essential Oil of Rosmarinus officinalis (Phytochemical Screening, Extraction, and Gas Chromatography)

Currently, climate change is disrupting life on Earth by causing imbalances in the biosphere. This work aimed to evaluate the impact of climate change on the content of primary and secondary metabolites and the yield of essential oil of Rosmarinus officinalis. Thus, the results of the conducted experiment show that the content of primary metabolites decreased with increasing temperature and decreasing precipitation along the experiment(proteins from 7.61% to 7.14%, carbohydrates from 6.92% to 5.64%, fats from 1.48% to 1.29% and dietary fiber from 4.96% to 4.22% and mineral composition: Ca from 7.67% to 5.98%, Mg from 8.61% to 7.01%, Fe from 7.53% to 7.21% and Mn from 6.85% to 3.97%), and the content of secondary metabolites increased in the second year when increasing the temperature by 5 °C and water stress by 50% (coumarin from 6.59% to 10.99%, saponins from 7.15% to 8.46%, tannin from 3.92% to 5.95%, alkaloids from 6.69% to 15.62% and flavonoid from 8.02% to 15.75%),but in the fourth year when the temperature continued to increase and water stress was 75% the content of secondary metabolites decreased (coumarin from 10.99% to 8.27%, saponins from 8.46% to 7.87%, tannin from 5.95% to 4.85%, alkaloids from 15.62% to 10.68% and flavonoid from 15.75% to 11.36%)and the same results were obtained for the yield of essential oil which increased in the second year and decreased in the fourth year. This GC analysis of the three essential oil samples shows that the majority of compounds in the three essential oils studied are cineole (S1:45.98%, S2:55.36%, S3:43.08%) followed by camphor (S1:17.44%, S2:21.44%, S3:21.56%) and Alpha-pinene (S1:9.30%, S2:8.34%, S3: 9.17%) and other compounds in low percentage.