Chemical composition and antimicrobial activity of essential oils and various extracts of endemic Onosma malatyana (Boraginaceae) from Anatolia.

The chemical contents of the endemic Onosma malatyana roots collected from Malatya/Türkiye were determined using the hydrodistillation and the soxhlet methods and antimicrobial activity analysis of the extracts was also performed. The hydrodistillation method applied to the roots of O.malatyana resulted in identifying 31 compounds according to their retention times in GC-MS analysis. Additionally, crude ethyl acetate and crude oil etheric extracts of O.malatyana roots contained 14 compounds each. This research identified that the main component of the essential oil obtained by the hydrodistillation method was palmitic acid comprising 56.48% of the total composition. Additionally, in the crude petroleum etheric extract, oleic acid methyl ester (31.22%); and palmitic acid (24.69%) were identified as the main components in the crude ethyl acetate extract. The results of the antimicrobial activities indicated that O.malatyana root extracts were particularly effective against Gram-positive bacteria, specifically S. aureus and B. subtilis .