Comparison between the Volatile Compounds of Essential Oils isolated from Rosemary (Salvia rosmarinus) and its Antioxidant Capacity from Ecuadorian Highlands

Introduction: Rosemary (Salvia rosmarinus) , its most used structural parts are the leaves, fresh or dried. Although it is common, there is little research on its phytochemical composition and antioxidant capacity. This research evaluated the essential oil composition and antioxidant activity of rosemary grown in two areas: urban (Quito) and rural (Atuntaqui, Imbabura).

Experimental Section: Aerial parts of both samples were collected to the extraction using solvent-free microwaves, under controlled conditions of time (40 and 8 minutes) and power (500 and 1350 MW). Identification and quantification of volatile compounds was performed by gas chromatography coupled to mass spectrometry¹ (GC-MS) and DPPH/ABTS assays

Results: The analysis revealed differences in yield, 0.93% in urban and 1.02% in rural areas. In addition, physicochemical parameters were evaluated: solubility and refractive index. Significant statistical differences in content and concentration were found according to the harvest site. Antioxidant activity was determined by DPPH methods obtaining (1.1470 and 1.1729) uM eq Trolox/g for urban and rural rosemary respectively; and ABTS with results in different conditions of 2.3309 and -1.2014 uM eq Trolox/g for urban area and in rural area 3.3840 and -0.9875 uM eq Trolox/g.

Conclusion: geoclimatic conditions influence the composition of rosemary essential oil, highlighting the presence of the contaminant tetrachloroethylene^2, being a component in both oils with concentrations of 2.87% and 13.10% for urban and rural rosemary, respectively. This revelation can be a know-how to use the rosemary species as an ecological fingerprint of the quality of the surrounding ecosystem.