Study on Essential Oil Compositions of Sage (Salvia Nemorosa L.) Collected From the North West of Iran at Different Growth Stages

Abstract

Salvia nemorosa L. or wood sage is a rich source of antimicrobial and antioxidant metabolites. Considering the importance of this medicinal plant and phytochemical diversity among its populations for local consumption and breeding porpuses this study was performed to determine and compare essential oil (EO) compositions of sage plants collected from four regions in the northwest of Iran including Ahar, Zonouz, Urmia, and Ardabil at two growth stages (vegetative and flowering) to finally demonstrate the effects of growth and location on EO features. The results showed the EO content of flowers in the studied regions were the highest in comparison with vegetative and flowering stages leaves. The percentage and the number of volatile compositions in the OE of flowers were those that presented the highest quantity. In Zonouz, 87.13% and 12 compositions while in Aahar, 80.20%, and 19 compositions. The lowest percentage and the number of volatile compositions in the OE of the flowers were seen in Urmia, 78.56%, and 13 compositions, while in Ardabil, these numbers were 68.61% and 10 compositions, respectively. Caryophyllene oxide had the highest content in all essential oils extracted, being the highest in the flowering stage leaves of the regions of Zonouz, Ardabil, and Urmia, respectively. In Ahar, unlike other areas, the most significant percentage of this compound was in the leaves of the vegetative stage. The oxygenated sesquiterpenes increased in the EO content of the flowers of the Urmia (46.31%), Ardabil (45.60%) and Zonouz (42.59%) regions. In contrast to other areas, for the Ahar region, the highest amount (36.18%) of oxygenated sesquiterpenes was observed in the EO of the leaves of the flowering stage. It can be concluded that different plant growth stages, plant harvest time, environmental conditions, primary habitat, and differences in climatic conditions can contribute to the concentration, type, and percentage of volatile compounds in the salvia EO.