Chemical composition and antimicrobial activity of an apolar extract from Lactuca serriola L. leaves

Lactuca serriola L. is an annual herbaceous plant species belonging to the Asteraceae family, called Prickly lettuce, Wild lettuce, and Jagged lettuce. L. serriola grows on grassy and rocky slopes in many regions in Europe, Asia, Australia, Africa, and North, Central and South America. The plant is used as a natural pharmaceutical agent in primary health care due to its analgesic, anti-inflammatory, antibacterial, and antioxidant properties, which are attributed to the compounds it contains. However, this is the first study demonstrating the antimicrobial activity of L. serriola essential oil. In this study, L. serriola essential oil was obtained by hydrodistillation of plant leaves and analyzed by Gas Chromatography -Mass Spectrometry (GS -MS); subsequently, antimicrobial properties of the essential oil were evaluated using agar dilution and broth microdilution methods. As a result of the GS -MS analysis, hexadecanoic acid, oleic acid, myristic acid, hexahydrofarnesyl acetone, beta-ionone, and n-tetradecyl butanoate were found as dominant components in the plant essential oil with the rate of 6.61%, 4.84%, 2.05, 1.55%, 1.3%, and 1.09% (v/v), respectively. The MIC value of L. serriola essential oil against Enterobacter aerogenes, Staphylococcus aureus , Pseudomonas aeruginosa , Candida albicans , and C andida tropicalis was found to be 0.94 mu LmL -1 , and MIC values were determined as 1.87 mu LmL -1 and 0.47 mu LmL -1 against Klebsiella pneumonia and Candida parapsilosis , respectively. These results have opened a new horizon regarding the usability of L. serriola essential oil as a pharmacological therapeutic antibacterial and antifungal agent.