Essential oil yield and composition of the Balkan endemic Satureja pilosa Velen. (Lamiaceae)

Authors: SEMERDJIEVA, IVANKA - Agricultural University Of Bulgaria; ZHELJAZKOV, VALTCHO - Oregon State University; Cantrell, Charles; ASTATKIE, TESS - Dalhousie University; ALI, ABBAS - University Of Mississippi

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2020
Publication Date: 2/13/2020
Citation: Semerdjieva, I.B., Zheljazkov, V.D., Cantrell, C.L., Astatkie, T., Ali, A. 2020. Essential oil yield and composition of the Balkan endemic Satureja pilosa Velen. (Lamiaceae). Molecules. 25(4):827. https://doi.org/10.3390/molecules25040827.
DOI: https://doi.org/10.3390/molecules25040827

Interpretive Summary: The genus Satureja (Lamiaceae) includes about 235 savory species of aromatic plants. They are widespread in the Mediterranean region, Asia, and America (Rustaiyan et al., 2004). In Europe, there are 12 naturally distributed Satureja (savory) species, of which 5 species are found in the Bulgarian flora. Savory species and their EO are traditionally used as spice and natural preservatives for food, as well as in the perfume, cosmetic and pharmaceutical industries. Satureja pilosa Velen (Lamiaceae) senso lato is a Balkan endemic plant, found on rocky outcrops on a limestone base in Stara Planina (the Balkan Mountains) and the Rhodope Mountains. The species was Bulgarian endemic until recently. The objective of this study was to assess the variability of essential oil (EO) content and composition of S. pilosa collected at 33 locations across the Balkan and Rhodope Mountains in Bulgaria using advanced statistical methods including cluster analysis. Overall, the EO content in dried aboveground biomass varied from 0.52% to 2.03%. More than 21 EO constituents were identified. This is the first comprehensive study on the endemic plant S. pilosa that identified several chemotypes based on the EO composition. The S. pilosa EO from the five different chemotypes exhibited larvicidal and mosquito repellent activity against Aedes aegypti. The identified chemotypes can be utilized for the development of new varieties with desirable compositions to meet specific industry needs and new antimosquito products.

Technical Abstract: Satureja pilosa Velen (Lamiaceae) senso lato is a Balkan endemic plant, found on rocky outcrops on a limestone base in Stara Planina (the Balkan Mountains) and the Rhodope Mountains. The species was Bulgarian endemic until recently. The objective of this study was to assess the variability of essential oil (EO) content and composition of S. pilosa collected at 33 locations across the Balkan and Rhodope Mountains in Bulgaria using advanced statistical methods including cluster analysis. Overall, the EO content in dried aboveground biomass varied from 0.52% to 2.03%. More than 21 EO constituents were identified, belonging to the groups of monoterpenes and sesquiterpenes. The monoterpenes were the predominant class, comprising 84.8% to 96.1% of the total EO. Phenolic monoterpenoids and aromatic monoterpene were the predominant groups of the monoterpenes class. Thymol and carvacrol were the major constituents of the phenolic monoterpenoids. Thymol varied from 36.6% to 67.1% and carvacrol was 52.4% - 93.0% of the total oil. P-cymene also varied widely, from 9.6% to 34.0%. Overall, there were significant variations with respect to the EO content and composition between different locations and also within a single location. We identified several chemotypes, based on the % ratio of the major constituents of the monoterpenes: (1) thymol and p-cymene; (2) thymol, p-cymene and y-terpinene; (3) carvacrol and p-cymene; (4) carvacrol, p-cymene and y-terpinene; and (5) carvacrol. This is the first comprehensive study on the endemic plant S. pilosa that identified several chemotypes based on the EO composition. The S. pilosa EO from the five different chemotypes exhibited larvicidal and mosquito repellent activity against Aedes aegypti. The identified chemotypes can be utilized for the development of new varieties with desirable compositions to meet specific industry needs and new antimosquito products.