The potential antifungal effects of Thymus vulgaris L., Thymus tosevii L., Mentha spicata L., and Mentha piperita L. (Labiatae) essential oils and their components against 17 micromycetal food poisoning, plant, animal and human pathogens are presented. The essential oils were obtained by hydrodestillation of dried plant material. Their composition was determined by GC-MS. Identification of individual constituents was made by comparison with analytical standards, and by computer matching mass spectral data with those of the Wiley/NBS Library of Mass Spectra. MIC’s and MFC’s of the oils and their components were determined by dilution assays. Thymol (48.9%) and p-cymene (19.0%) were the main components of T. vulgaris, while carvacrol (12.8%), α-terpinyl acetate (12.3%), cis-myrtanol (11.2%) and thymol (10.4%) were dominant in T. tosevii. Both Thymus species showed very strong antifungal activities. In M. piperita oil menthol (37.4%), menthyl acetate (17.4%) and menthone (12.7%) were the main components, whereas those of M. spicata oil were carvone (69.5%) and menthone (21.9%). Mentha sp. showed strong antifungal activities, however lower than Thymus sp. The commercial fungicide, bifonazole, used as a control, had much lower antifungal activity than the oils and components investigated. It is concluded that essential oils of Thymus and Mentha species possess great antifungal potential and could be used as natural preservatives and fungicides.

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Seed extracts from eight grape cultivars (Vitis vinifera) growing in Serbia were screened for their polyphenolic composition by means of HPLC/ /PDA/ESI/MS analysis. The study revealed 34 phenolic compounds belonging to the following groups: flavan-3-ol monomers, proanthocyanidins, flavonols, hydroxycinnamic acid and hydroxybenzoic acid derivatives. The quantities of the main constituents were determined using PDA/HPLC. Qualitative and quantitative differences among the cultivars were observed.The phenolic compounds in grapes can be divided into two main groups: phenolic acids (localized mainly in the skin and pulp) and flavonoids. The most common phenolic acids in grape include cinnamic and benzoic acid derivatives. Flavonoids include colorless flavan-3-ols, flavonols and red and blue anthocyanins. 5 The most abundant phenolics isolated from grape seeds and skins are flavan-3-ols (catechin and epicatechin) and their oligomers and polymers (proanthocyanidins). The outer seed coat contains the majority of both the monomeric and polymeric flavan-3-ols (2 to 5 times more than the endosperm). 6 Grape skins also contain anthocyanins which contribute to their red or blue color. 7,8 Various conditions (time, solvent, and the manner) for the extraction of polyphenols from grape seeds are described in the literature. Due to the acidic lability of interflavan linkages within proanthocyanidins and the susceptibility of polyphenols to oxidation, a valid extraction method should provide for the complete as possible extraction of the polyphenolics while limiting their degradation. 9 Methanol/water 10,11 or acetone/water systems 12 are the common solvents used for extracting polyphenols from grape seeds. In particular, lower molecular weight polyphenols, such as phenolic acids, anthocyanins, and flavanol monomers and oligomers, are well extracted with methanol, while the higher molecular weight flavanols are better extracted with aqueous acetone than with methanol. [13][14][15][16] Several methods for the analysis of polyphenols have been proposed in the literature. Most of them are based on high performance liquid chromatography (HPLC) coupled with either a photodiode array (PDA) detector or a mass spectrometer (MS). Reverse phase columns are favorable, using acetonitrile and acidic water solutions as eluents. 17 Since UV detection depends upon the chemical structure of a molecule, several wavelengths could be selected for monitoring. Red-colored anthocyanins show an absorbance maximum at around 520 nm; yellow-colored flavonols display an absorbance maximum at around 360 nm; hydroxycinnamic acids can be specifically detected by their high absorbance around 320 nm. Flavan-3-ols show no specific absorbance and have a maximum around 280 nm, as do all the above-mentioned phenolics. 18 Many studies proved that procyanidins and other polyphenolics from grape seed could be the key compounds responsible for various beneficial effects for human health. 19,20 These effects are mainly associated with the antioxidant activity of the phenol...

Four flavones (1-4) and nine sesquiterpene lactones (5-13), one of them (5) a new compound, were isolated from the aerial parts of Achillea atrata L. subsp. multifida. Although the crude extract demonstrated in vitro inhibitory activity against Candida albicans and Bacillus subtilis, all isolated flavones were active against B. subtilis. Flavones 1, 2, and 3 were also active against C. albicans, while 1 and 3 exhibited activity against E. coli, as well. None of the tested lactones (7, 9, 12, and 13) showed any antimicrobial activity.