Volume 60 (2014): Edition 2 (June 2014)

The aim of the studies conducted in 2012-2013 was to compare the chemical composition of essential oils isolated from wild thyme (Thymus serpyllum L.) by hydrodistillation in Deryng and Clevenger apparatus. GC-MS analysis of the isolated oils revealed that carvacrol (42.81-45.24%), γ-terpinene (7.68-9.04%), β-caryophyllene (5.28-9.10%), β-bisabolene (5.76-6.91%) and carvacrol methyl ether (4.92-6.09%) were the major components of all the samples. On the basis of the obtained data it was proved that the type of distillation apparatus had no significant effect on the content of the main essential oil constituents of wild thyme. However, based on the means for both years of the study it was proved that hydrodistillation in Deryng apparatus was more effective for carvacrol concentration, while in Clevenger apparatus - for y-terpinene and carvacrol methyl ether concentration. The type of distillation apparatus had no significant effect on the content of the other essential oil constituents.

Potentilla erecta is a therapeutic plant used in folk medicine to treat inflammatory states, wounds and diseases of the alimentary tract. The results of the study reveal the effects of an aqueous extract of P. erecta rhizome on certain microorganisms occurring in food. The main components of the extract were catechins. The extract was shown to display an inhibiting effect against Gram-positive bacteria such as Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 6633, as well as against yeast such as Candida lipolitica KKP 322 and Hansenula anomala R 26. The extract did inhibit the growth of Gram-negative bacteria, however, no inhibiting effects were observed on moulds in the studied range of concentrations, i.e. 0.13 to 64 mg dry matter/ml.

In this study the antibacterial and antifungal activities of extracted Achillea latiloba Ledeb. ex Nordm (Asteraceae) samples in acetone, ethyl acetate, ethanol, methanol and dimethyl sulfoxide (DMSO) from Trabzon Province (Turkey) were investigated. Antimicrobial activity of A. latiloba varied depending on the extract of samples, dosage of extracts, and the extraction solvents for all test microorganisms. Staphylococcus aureus, Streptococcus salivarius, Klebsiella pneumoniae, Escherichia coli, Salmonella enteritidis, Streptococcus pneumoniae, Bacillus cereus, Listeria monocytogenes, Streptococcus mutans, Pseudomonas aeruginosa, Bacillus licheniformis, Micrococcus luteus, Bacillus subtillis, Proteus vulgaris and Candida albicans were studied with use of disc diffusion and agar dilution method. The results indicated that each of the crude extracts of Achillea latiloba exhibited a more or less pronounced antibacterial and antifungal potency both in Gram-positive and Gram-negative bacteria and fungi. While in the Gram-negative group, the most sensitive microorganism to Achillea latiloba were S. enteritidis and Streptococcus mutans which is Gram-positive. In the Gram-positive group, the microorganisms most sensitive to Achillea latiloba were Streptococcus mutans and L. monocytogenes. However, the least sensitive microorganism was P. vulgaris. The results presented in this paper suggest that Achillea latiloba possesses additional antimicrobial activities that has an effect against some Gram-negative, Gram-positive bacteria and fungi.

Essential oil from Allium sativum was isolated and investigated for its repellent, insecticidal, ovipositional and egg hatching inhibition activities against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae). A. sativum essential oil repelled bruchid adults at a very low concentration in choice oviposition assay. A. sativum essential oil caused both fumigant and contact toxicity in C. chinensis adults in a concentration dependent manner. Oviposition potency of C. chinensis adults was reduced significantly when sublethal concentrations of A. sativum essential oil were applied by fumigation and contact method. In chronic toxic-ity assay, A. sativum essential oil reduced F₁ progeny emergence, damage and weight loss in seeds. Findings of the present study suggest that A. sativum essential oil can be useful as promising agent in insect pest management programme.

Lavender (Lavandula angustifolia) is a shrub of the family Lamiaceae, native to the Mediterranean region. The material used for herbal purposes includes lavender flowers (Lavandula flores) containing essential oil (3%), anthocyanins, phytosterols, sugars, minerals, and tannins. The qualitative and quantitative composition of the essential oil of lavender is variable and depends on genotype, growing location, climatic conditions, propagation, and morphological features. The essential oil contains over 300 chemical compounds. The dominant components are linalool, linalyl acetate, terpinen-4-ol, acetate lavandulol, oci-mene, and cineole. Lavender essential oil has good antioxidant and antimicrobial activities and a significant positive effect on the digestive and nervous systems. Lavender extract prevents dementia and may inhibit the growth of cancer cells, while lavender hydrolate is recommended for the treatment of skin problems and burns.