Antimicrobial activities of some medicinal essential oils

S u m m a r y in this study, the antimicrobial properties of essential oils obtained from Coriandrum sativum, Foeniculum vulgare Miller, Salvia triloba, Laurus nobilis L., Citrus limon and Origanum smyrnaeum L. were investigated. A total of eight microbial organisms belonging to six species of bacteria, namely Salmonella typhimurium, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli and Enterobacter aerogenes, as well as two fungi, Candida albicans and Aspergillus niger, were studied using a disc-diffusion and agar dilution (minimal inhibition concentration) method. the antimicrobial activity of essential oils obtained from the six plants turned out to be more effective in the case of bacteria than against fungi. the antimicrobial activity against Gram-positive bacteria was more pronounced than against Gram-negative ones. All the investigated plants are known as having healing properties and are used to treat various diseases. the essential oils obtained from L. nobilis and O. smyrnaeum showed the highest antifungal activity against C. albicans and A. niger, while the essential oils obtained from F. vulgare showed the highest antimicrobial activity against P. aeruginosa and E. coli. On the other hand, the essential oils obtained from O. smyrnaeum showed stronger antibacterial activity in the case of E. aerogenes and S. aureus, but were not equally effective against E. coli. the other crude essential oils showed varied levels of antibacterial and antifungal activity. the minimal inhibition concentrations (Mic) of the essential oils obtained from O. smyrnaeum and of those obtained from L. nobilis ranged from 1.17 to 4.71 mg/ml, and 2.4 to 19.2 mg/ml, respectively

Phenylethanoid glycosides in Plantago media L. organs obtained in in vitro cultures

Micropropagation of Plantago media L. and the presence of phenolic compounds in organs of multiplied plants were investigated for the first time. Multiplication of plant material was achieved in shoot-tip cultures and via direct organogenesis on Murashige and Skoog (MS) medium with four variants of plant growth regulators (M1–M4). The best multiplication coefficient – 9.2 was obtained in seedling shoot-tip cultures on MS medium M3 with BA 0.2 mg/L and IAA 1.0 mg/L. Methanol extracts prepared separately from shoots and roots of in vitro- derived plantlets were found to contain typical of the genus Plantago L. phenylethanoid glycosides as the only phenolics. Acteoside and plantamajoside were the major compounds – both known to possess a wide range of promising biological activities applicable for medicinal (therapeutic) and cosmetic uses. Martynoside, as a trace constituent, was also found for the first time in the studied species. The quantitative screening of the extracts by TLC video densitometric method showed a higher content of acteoside in shoots (range 62.43–93.03 mg/g, dry weight) and plantamajoside in roots (range 22.45–44.08 mg/g); the highest recorded values – 93.03 mg/g and 44.08 mg/g, respectively, were found in the organs obtained on MS medium M4 with BA 2.0 mg/L