Investigation of Essential Oil Chemical Polymorphism of Salvia fruticosa naturally Growing in Lebanon

Abstract

Salvia fruticosaa perennial aromatic plant, endemic to the Mediterranean region, is the most used medicinal plant in Lebanon. S. fruticosa essential oils (EOs) are widely acknowledged in the Lebanese traditional medicine to treat several ailments. Plant samples were harvested at various months of the year 2013, from 4 different Lebanese areas: Baabda, Ansariyeh, Harissa and Nahr Ibrahim. Fresh herb was either air dried or lyophilized. EOs were obtained using 2 extraction techniques: Solvent-Free Microwave Extraction (SFME) and conventional hydro distillation. The chemical variability of Lebanese S. fruticosa EO quantity and quality was assessed according to harvesting time and region, drying methods and EO extraction techniques. GC/MS showed that the major compounds in the oils were: eucalyptol (18.3-83.7 %), trans-anethole (0.00-61.7 %), β-caryophyllene (0.00-38 %), and camphor (0.00-16.7 %). EO yields were affected by plant’s growth stages, drying methods and EO extraction techniques. EO extraction methods and harvesting time and region had an impact on EO chemical composition whereas tested drying methods had no significant influence. Our study highlighted 4 different chemotypes for S. fruticosa EO: eucalyptol, camphor, α-thujoneand trans-anethole. For the first time in our study, trans-anethole was found as distinguishable chemotype.