Chemical composition and antimicrobial activity of essential oils and various extracts of endemic <i>Onosma malatyana</i> (Boraginaceae) from Anatolia

The chemical contents of the endemic <i>Onosma malatyana</i> 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 <i>O.malatyana</i> resulted in identifying 31 compounds according to their retention times in GC-MS analysis. Additionally, crude ethyl acetate and crude oil etheric extracts of <i>O.malatyana</i> 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 <i>O.malatyana</i> root extracts were particularly effective against Gram-positive bacteria, specifically <i>S. aureus</i> and <i>B. subtilis</i>.