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Amaranth species represent a diverse group of plants. Many of them are a rich source of secondary metabolites with many positive biological effects. Total phenolic, total flavonoid and rutin content, antioxidant activity against superoxide and hydroxyl radicals, FRAP (Ferric-reducing ability of plasma) assay and DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging assay were determined in ethanol extracts of dried leaves of the new Slovak amaranth varieties ‘Pribina’ and ‘Zobor’. The amount of total phenolic substances (‘Pribina’ GAE 38.3 mg.g−1 DM and ‘Zobor’ GAE 26.1 mg.g−1 DM), content of total flavonoids (‘Pribina’ QE 26.5 mg.g−1 DM and ‘Zobor’ QE 20.3 mg.g−1 DM) and rutin (‘Pribina’ 50.8 mg.g−1 DM and ‘Zobor’ 15.2 mg.g−1 DM) were higher in the variety ‘Pribina’, compared to the variety ‘Zobor’. A statistically higher antioxidant activity against superoxide radical (1.63%·mg−1g−1 DM), hydroxyl radical (3.20%.mg−1g−1 DM), FRAP assay (292.80 µmol.L−1·mg−1.g−1 DM) and DPPH (54.2 ± 1.78 µg.mL−1 DM) were detected in the ‘Pribina’ variety. Antiradical and antioxidant activities of both extracts showed high positive correlations in relation to the content of total phenolic substances, total flavonoids and rutin. Amaranth is an undemanding crop on specific environmental conditions and is resistant to abiotic and biotic stress.

In the present study, in vitro hydroxyl radical scavenging activities, total phenols and terpene contents in 70% ethanol extracts were evaluated. Samples of crushed (CB) and non-crushed ripe juniper berries (NCB) collected at five localities in North-East Slovakia during the years 2012&ndash, 2014 were compared. Standard or modified methods for determining phytochemical and antioxidant activity were used together with a novel method for the evaluation of the results after the correction of the measured values per gram of dry matter (DM). Statistically significantly higher DM contents (average values for three years) were found in the CB extracts (ranging from 18.86 to 21.91 mg/mL) in comparison to those for NCB (ranging from 2.59 to 9.90 mg/mL). Depending on the localities and years, the hydroxyl radical scavenging activity ranged from 15.52 to 32.85% for NCB and from 65.59 to 88.12% for CB, respectively. The contents of total phenols ranged from 43.75 to 246.75 mg gallic acid equivalents (GAE)/L (NCB) and from 151.84 to 278.19 mg GAE/L (CB), respectively. However, the higher content of total phenols per gram of DM was found in the NCB extracts (8.49&ndash, 42.23 mg GAE/g DM) and then in CB (6.87&ndash, 18.77 GAE/g DM). The results obtained in this study showed a higher efficiency for extraction from juniper berries in 70% ethanol if the pericarp was disrupted in comparison to that achieved with the maceration of intact berries.

The aim of the present study was the achievement of sterile shoot cultures from peppermint (Mentha × piperita L. cv. ʻKristinkaʼ), their multiplication and the evaluation of the production of essential oils in in vitro conditions. The study was carried out by culturing the nodal segments both on basal or on media supplemented with different concentrations of growth regulators (2,4-D, kinetin, BAP, ZEA) or elicitors (CoCl2). The growth of nodal segments did not showed differences after subculturing, neither when cultivated on media supplemented with 2,4-D or CoCl2. The supplementation of 0.5 mg L−1 BAP caused an increase in the number of de novo formed shoots. The composition of the essential oils showed remarkable differences, with an enhancement of the percentage of menthofuran after the supplementation of 2,4-D and CoCl2 or of pulegone after application of BAP and ZEA.

The present study evaluated the influence of some environmental factors on the quantity and composition of essential oil (EO) in ripe berry cones of Juniperus communis L. The berry cones were collected from juniper shrubs growing wild at five localities of north-east Slovakia during the years 2012–2014. The EO yield ranged from 0.4 to 1.9%, depending on the locality and year. In the EO, eight monoterpenes (α-pinene, β-pinene, β-myrcene, sabinene, limonene, terpinene-4-ol, borneol, bornylacetate) and one sesquiterpene (β-caryophyllene) were identified. The dominant component was the monoterpene α-pinene, ranging from 31.0 to 49.0%. The amount and composition of the EO was affected by soil composition (content of humus and pH) and topographic environmental factors, including air temperature and precipitation. According to the composition of the EO, the studied juniper shrubs belong to the α-pinene chemotype.

This paper deals with the chemical characterization of anthocyanins in elderberry cultivar ‘Haschberg’ grown in the Slovak Republic. Crude and purified extracts were analyzed. The impact of lyophilization on the qualitative profile was also studied. The anthocyanin profile of elderberry harvested from the private company, ZAGRO s.r.o. Michalovce (Eastern Slovakia), was investigated using liquid chromatography on reverse phase coupling atmospheric pressure ionization with ion-trap and time-of-flight (LC/MS-IT-TOF). Our results show that the anthocyanin extraction method can have an important impact on its degradation. Purified extracts showed high amount of anthocyanins. Seven different anthocyanins were identified in extracts before and after freeze-drying.

A new menthol cultivar of Mentha x piperita L. bred in East Slovakia was evaluated for the biological activity of its essential oils (EOs). The content and composition of the EO components changed during plant development and the different effects of samples collected each month (April - September) within the growing season were noted. EOs are considered to be an important source of potential allelochemicals. Changes in EO composition influenced phytotoxic activity. Stimulation and inhibition of seed germination and root elongation occurred with different EO concentrations. The four tested bacterial strains presented different resistance to the samples collected in different growing periods.