Effect of Harvesting Time on Chemical Components of Sage (Salvia officinalis L.) From Iran

Sage (Salvia officinalis L.) is perennial shrub and is one of the most important medicinal plants of the Lamiaceae family. The objective of this study was to evaluate the effect of different harvesting stages on contents, and essential oil components of sage. The essential oil from the aerial parts of the plant that were collected at different times was extracted by hydro-distillation in 2021 in the province of Isfahan in center Iran. Plants were harvested in four stages, i.e. the before blooming, beginning of blooming, full blooming and fruit stage. Results of mean comparisons revealed that the highest oil percentage (1.7%) was obtained at the stage of before blooming and the lowest oil percentage (0.36%) was obtained at the stage of fruit set. Based on results obtained from GC/MS analysis, in total, 39, 36, 32 and 37 constituents were identified in the essential oils of sage in the before blooming, beginning of blooming, full blooming and fruit stages, respectively. The major identified essential oil compounds were α-thujone (26.18–39.53%), camphor (10.39–19.78%), β-thujone (4.65–14.12%) and 1,8-cineol (7.75–13.98%). α-thujone as one of the major constituents of all samples was lower in the stage of before blooming (26.18%) and gradually increased in subsequent harvesting times to reach a maximum in the fruiting set (39.53%). Camphor was another compound where the highest (19.78%) was observed in beginning of blooming stage. The results showed that the harvesting time may have a significant effect on the essential oil yield and composition of sage. Our findings in sage, may pave the way to optimize the quality and quantity of sage essential oil to identify the best harvest time for pharmaceutical industries.