Comparative Evaluation of the Essential Oil of the New Ukrainian Lavandula angustifolia and Lavandula x intermedia Cultivars Grown on the Same Plots

New cultivars of lavender adapted to arid steppe conditions were developed by the Institute of Rice of Ukrainian National Academy of Agrarian Sciences (NAAS). This work is a part of the characterization process of the new cultivars. The chemical composition of the essential oil of the seven new Lavandula angustifolia and eight new Lavandula x intermedia cultivars was investigated and compared. In total, 71 different compounds were identified. Linalool and linalool acetate were the main components in both species in ranges of 26.14-57.07% and 9.08-24.45%, respectively. They were followed by terpinen-4-ol (2.16-22.44%), lavandulyl acetate (2.12-10.23%), and lavandulol (1.30-3.14) in the case of L. angustifolia and camphor (10.11-12.55%), borneol (5.49-8.71%), and eucalyptol (0.47-7.41%) in the case of L. x intermedia. The oils had a valuable terpene profile-a high linalool content and the substantial presence of lavandulol and its ester. Nevertheless, they did not comply with the industry standards, mostly due to high levels of terpinene-4-ol. Evidently, a high content of terpinen-4-ol is a characteristic feature of L. angustifolia oils bred in Ukraine. Additionally, the LA3 cultivar yielded an oil with some of the highest linalool contents reported in the literature. Statistical analysis and literature data allowed for the comparative analysis of the gathered data. MANOVA, PCA, and HCA marked caryophyllene oxide as another potential differentiating compound between studied species.

Chromatographic profiles and antimicrobial activity of the essential oils obtained from some species and cultivars of the Mentheae tribe (Lamiaceae)

The present study was focused on the chemical composition and antimicrobial activity of the essential oils (EsO) obtained from five Lamiaceae representatives grown in the south of Ukraine. Among them are Salvia sclarea L., Monarda didyma (cultivar ‘Cambridge Scarlet’), Thymus pulegioides (cultivar ‘2/6-07’), Thymus vulgaris (cultivar ‘Jalos’), and Thymus serpyllum L. The component analysis of the EsO was carried out by gas chromatography method coupled with mass spectrometry (GC–MS). The antimicrobial properties of the EsO were determined using the agar diffusion test against widespread pathogenic bacterial strains (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Streptococcus pyogenes) and opportunistic yeast Candida albicans. The EsO of Thymus serpyllum and Thymus vulgaris (cultivar ‘Jalos’) displayed noteworthy antibacterial properties against a wide spectrum of the microorganisms. These antimicrobial properties could be attributed to the high content of aromatic monoterpenoid thymol (52.56% and 47.33%, respectively). The EsO of Salvia sclarea with the dominance of linalyl acetate (45.51%) and linalool (38.98%) as well as Thymus pulegioides (cultivar ‘2/6-07’) containing α-citral (27.10%) and β-citral (17.11%) demonstrated the strongest antimicrobial effects on typical and clinical strains of Staphylococcus aureus with the inhibition zones in the range of 24.0–31.0 mm. The Salvia sclarea EsO demonstrated the most significant effect against clinical strains of Candida albicans. In conclusion, the present study revealed the chemical composition of five Lamiaceae species and cultivars grown in the south of Ukraine and considerable antimicrobial activity of the tested EsO, especially against the typical and clinical strains of Staphylococcus aureus and Candida albicans. The obtained results could be perspective for applying in the pharmaceutical industry and for the conservation of food and cosmetic products.

Chemical Composition of the Essential Oil of the New Cultivars of Lavandula angustifolia Mill. Bred in Ukraine

Lavender, otherwise known as Lavandula angustifolia Mill., is widely used in landscaping, and its oil is a valuable raw material used in many industries. Therefore, new varieties of this plant are bred. The essential oil composition obtained from fresh flowers of thirteen new Ukrainian cultivars of L. angustifolia were analysed by GC-MS, and eighty-two components were identified. Linalool and linalyl acetate were principal constituents of all of the samples, and ranged from 11.4% to 46.7% and 7.4% to 44.2%, respectively. None of the studied samples fulfilled the requirements of Ph. Eur. and ISO 3515:2002. The main reason was a high content of α-terpineol (0.5-4.5%) and/or terpinene-4-ol (1.2-18.7%). Our results are in line with multiple researchers showing that the studied lavender oils do not comply with the industry standards despite their authenticity. We also investigated the effect of the growth year on the chemical composition of five tested cultivars grown on the same plots and noticed a considerable variability between years. The obtained experimental data did not show a significant inter-year trend for the content changes of the major components. Our results allow us to deeply characterize the new cultivars and evaluate their oil for a possible use in the industry, or to designate them for future selective breeding.

Antioxidant capacity of plant raw material of Scutellaria baicalensis Georgi

The aim of this study was to evaluate antioxidant capacity of Scutellaria baicalensis Georgi from two regions of Ukraine: Kyiv city (M. M. Gryshko National Botanical Garden of NAS of Ukraine (NBG)) and Kherson region (Experimental Facility “Novokakhovska” of Rice Research Institute of Ukrainian Academy of Agrarian Sciences (EFN of RRI)). Observation of plants and biochemical analyses conducted with plants collected in the stage of flowering. In study investigated and compared above-ground part of plants and separated organs: inflorescences, stems, leaves. Measured morphometric parameters (height of plants, length, and width of leaves, length, and diameter of inflorescence, the diameter of the stem) showed that the most variable was the length of inflorescence (12.79%) for NBG sample and diameter of the stem (33.33%) for EFN of RRI sample. Ethanolic extracts were screened for the antioxidant capacity. As standards were used gallic acid for polyphenol content (GAE), quercetin for flavonoids (QE), caffeic acid for phenolic acids (CAE), Trolox for antioxidant capacity (TE). The total content of polyphenol compounds was 42.43 – 86.13 mg GAE.g-1 DW (dry weight) (NBG sample) and 28.06 – 96.76 mg GAE.g-1 DW (EFN of RRI sample). The content of flavonoids was 9.39 – 62.97 mg QE.g-1 DW (NBG sample) and 10.64 – 66.07 mg QE.g-1 DW (EFN of RRI sample). The concentration of phenolic acids was 2.60 – 16.13 mg CA.g-1 DW (NBG sample) and 12.02 – 30.12 CA.g-1 DW (EFN of RRI sample). Antioxidant activity of plant extracts was measured by DPPH assay and reducing power method. The first method indicated an antioxidant ability 8.24 – 8.56 mg TE.g-1 DW (NBG sample) and 7.63 – 8.83 mg TE.g-1 DW (EFN of RRI sample). Reducing power of extracts was 51.48 – 306.09 mg TE.g-1 DW (NBG sample) and 63.33 – 260.24 mg TE.g-1 DW (EFN of RRI sample). Very strong positive correlation identified between total polyphenol content, total flavonoid content and reducing power. Scutellaria baicalensis is a rich source of antioxidants and potential raw of further pharmacological study in Ukraine as well as in other regions for improving and enrichment of relevant production.