Hydrolates, also referred to as hydrosols, floral or distillate waters, as well as aromatic waters, are produced in the same isolation process with essential oils by steam distillation. A small amount of essential oil constituents is dissolved in hydrolates providing specific organoleptic properties and flavor, as well as biological activity which makes them useful as raw material in many industries. Their popularity is still on the rise, especially in aromatherapy. The objective in this review is to analyze the chemical compositions of hydrolates and their corresponding essential oils, as well as biological activity of hydrolates (antimicrobial, antioxidant and antiinflamatory) and potential uses, not only in food industry for flavoring, and preservation of fresh-cut fruits and vegetables, but also as functional (soft) drinks. However, hydrolates can be used in aromatherapy and cosmetics, as well as in organic agriculture and aquaculture.

Lavandula sp. essential oil and hydrolate are commercially valuable in various industry branches with the potential for wide-ranging applications. This study aimed to evaluate the quality of these products obtained from L. x intermedia cv. ‘Budrovka’ for the first time cultivated on Fruška Gora Mt. (Serbia) during three successive seasons (2019, 2020, and 2021). Essential oil extraction was obtained by steam distillation, and the composition and influence of weather conditions were also assessed, using flowering tops. The obtained essential oils and hydrolates were analysed by gas chromatography with a flame ionization detector (GC-FID) and gas chromatography coupled to mass spectrometry (GC-MS). A linear regression model was developed to predict L. x intermedia cv. ‘Budrovka’ essential oil volatile compound content and hydrolate composition during three years, according to temperature and precipitation data, and the appropriate regression coefficients were calculated, while the correlation analysis was employed to analyse the correlations in hydrolate and essential oil compounds. To completely describe the structure of the research data that would present a better insight into the similarities and differences among the diverse L. x intermedia cv. ‘Budrovka’ samples, the PCA was used. The most dominant in L. intermedia cv. ‘Budrovka’ essential oil and hydrolate were oxygenated monoterpenes: linalool, 1,8-cineole, borneol, linalyl acetate, and terpinene-4-ol. It is established that the temperature was positively correlated with all essential oil and hydrolate compounds. The precipitations were positively correlated with the main compounds (linalool, 1,8-cineole, and borneol), while the other compounds’ content negatively correlated to precipitation. The results indicated that Fruška Gora Mt. has suitable agro-ecological requirements for cultivating Lavandula sp. and providing satisfactory essential oil and hydrolate.

The objective of this study was to evaluate wild growing Satureja kitaibelii, Thymus serpyllum, Origanum vulgare, Achillea millefolium and Achillea clypeolata with respect to their essential oil (EO) content, composition and antimicrobial activity. The five species were collected at Mt. Rtanj and the village of Sesalac, Eastern Serbia. The main EO constituents of Lamiaceae plants were p-cymene (24.4%), geraniol (63.4%) and germacrene D (21.5%) in Satureja kitaibelii, Thymus serpyllum and Origanum vulgare ssp. vulgare, respectively. A. millefolium EO had multiple constituents with major ones being camphor (9.8%), caryophyllene oxide (6.5%), terpinen-4-ol (6.3%) and 1,8-cineole (5.6%), while the main EO constituents of A. clypeolata were 1,8-cineole (45.1%) and camphor (18.2%). Antimicrobial testing of the EO showed that Staphylococcus aureus (Gram-positive) was more sensitive to all of the tested EOs than Escherichia coli (Gram-negative). S. kitaibelii EO showed the highest antimicrobial activity against both tested bacterial strains. This is the first study to characterize the EO composition and antimicrobial activity of these five medicinal species from Eastern Serbia in comparison with comprehensive literature data. The results can be utilized by the perfumery, cosmetics, food and pharmaceutical industries, but also for healing purposes in self-medication.

Although all ground beetles have pygidial glands homologous in structure and function, there are many differences among species, often significant, in terms of chemical composition of the secretion and morphology of the gland components. In this paper, two predatory ground beetle species of the genus Carabus, namely C. (Tomocarabus) convexus and C. (Procrustes) coriaceus, were subjected to chemical, morphological and histological study of their pygidial glands and the glands’ secretions. Altogether, three carboxylic acids were isolated, and the pygidial gland reservoir and other glandular parts are morphologically described in the study. We also tested whether there exist differences in chemical content of the secretion obtained by upsetting the beetles in a traditional way and that obtained directly from intact reservoirs. Detailed data on morphology of the pygidial glands of both species are presented, as well as updated information about the chemical components of the glandular secretions. Apart from tiglic and methacrylic acids, which are typical for Carabus pygidial secretions, we also found benzoic acid as a minor component of the secretion in both species. In addition, a chemotaxonomic overview of Carabus taxa is given in the paper.

Unlike other studies that only determined the chemical composition of essential oils depending on their geographic origin, this research investigated the effect of weather conditions (temperature, precipitation, and insolation) on the chemical composition of Nepeta nuda L. essential oil. The collection of wild-growing N. nuda was carried out during three successive years, 2019, 2020, and 2021 at Rtanj Mountain (Serbia) on the same date (July 7th). Essential oil extraction from the plant was performed by hydro-distillation. After gas chromatographic-mass spectrometric analysis, a total of 102 volatile compounds were separated from N. nuda, during the observed period, 28 were unidentified, compromising between 5.0% and 8.7%, depending on the year. A multiple linear regression model was created, and statistical analyses were performed to provide knowledge about the prediction, feature profile, and the similarity in contents of active compounds of the N. nuda essential oil. The influence of temperature on the accumulation of the most abundant component, 1,8-cineole, was positive, while the impact of precipitation and insolation was negative. According to the cluster tree, there are four chemotypes of N. nuda essential oil: with nepetalactone, 1,8-cineole, mixed (nepetalactone+1,8-cineole+germacrene D), and nonspecific chemotypes. Bearing in mind that the biological activity of a raw material depends on the chemotype and environmental factors, this is a topic that deserves a more detailed approach. The N. nuda and its essential oil are promising materials with high biological potential, and these deserve further detailed investigation.