Essential Oil Composition Analysis, Antimicrobial Activities, and Biosystematic Studies on Six Species of Salvia

The essential oil constituents, antimicrobial properties, and biosystematic characteristics (morphological, palynological, and anatomical features) of six Salvia species from different regions of Turkey were investigated qualitatively and quantitatively in this study. The chemical composition of the essential oils of dried aerial parts of Salvia species, i.e., S. absconditiflora, S. ceratophylla, S. multicaulis, S. verbenaca, S. viridis, and S. syriaca were analyzed by GC-MS. The main constituents of the six Salvia species studied were 1,8-cineol, caryophyllene oxide, spathulenol, and borneol in different ratios. The antimicrobial activity of the essential oil extracted from the aerial parts of species of the genus Salvia was tested by the disc diffusion method. The essential oils of Salvia species showed different antimicrobial activity against the studied microorganisms. The highest antimicrobial activity against E. coli was observed in S. multicaulis and the highest antimicrobial activity against K. pneumoniae was observed in S. verbenaca. The morphology of the stem, leaf, bract, and flower structures of the Salvia species were analyzed in this study. Anatomical investigations focused on the root, petiole, and stem in more detail. Our research has broadened the criteria of anatomical characters unique to the Salvia species. Under light microscopy, the pollen grains of the six species belonging to Salvia were isopolar and radially symmetrical. The properties of the essential oil constituents, antimicrobial properties, and biosystematic data obtained in this study contribute to the bioactive and biosystematic studies of Salvia species used for food, pharmaceutical, and cosmetic purposes.

Automated summary

This study investigated the essential oil constituents, antimicrobial properties, and biosystematic characteristics of six Salvia species from Turkey. The chemical composition of the essential oils was analyzed, and 1,8-cineol, caryophyllene oxide, spathulenol, and borneol were found to be the main constituents. The essential oils showed different antimicrobial activity against tested microorganisms, with S. multicaulis having the highest activity against E. coli and S. verbenaca having the highest activity against K. pneumoniae. Morphological and anatomical analyses were also conducted, and the pollen grains of the Salvia species were found to be isopolar and radially symmetrical. The obtained data contribute to the bioactive and biosystematic studies of Salvia species for various purposes.