Piotr Borysiuk

The purpose of this study was to characterize ethanol extracts from leaves and flowers of two ecotypes (PL—intended for industrial plantations and KC—intended for cut flowers) of Lavandula angustifolia Mill. The plant was cultivated in 2019 in southern Poland as part of a long-term research plan to develop new varieties resistant to difficult environmental conditions. The collected leaves and flowers were used to prepare ethanol extracts, which were then analyzed in terms of phytochemical composition and antioxidant, bactericidal, and fungicidal properties. Using UPLC techniques, 22 compounds belonging to phenolic acids and flavonoids were identified. UPLC test results indicated that ethanol extracts from leaves and flowers differ in phytochemical composition. Lower amounts of phenolic acids and flavonoids were identified in leaf extracts than in flower extracts. The predominant substances in the flower extracts were rosmarinic acid (829.68–1229.33 µg/g), ferulic acid glucoside III (810.97–980.55 µg/g), and ferulic acid glucoside II (789.30–885.06 µg/g). Ferulic acid glucoside II (3981.95–6561.19 µg/g), ferulic acid glucoside I (2349.46–5503.81 µg/g), and ferulic acid glucoside III (1303.84–2774.17 µg/g) contained the highest amounts in the ethanol extracts of the leaves. The following substances were present in the extracts in trace amounts or at low levels: apigenin, kaempferol, and caftaric acid. Leaf extracts of the PL ecotype quantitatively (µg/g) contained more phytochemicals than leaf extracts of the KC ecotype. The results obtained in this study indicate that antioxidant activity depends on the ecotype. Extracts from the PL ecotype have a better ability to eliminate free radicals than extracts from the KC ecotype. At the same time, it was found that the antioxidant activity (total phenolic content, ABTS•+, DPPH•, and FRAP) of PL ecotype leaf extracts was higher (24.49, 177.75, 164.88, and 89.10 μmol (TE)/g) than that determined in flower extracts (15.84, 125.05, 82.35, and 54.64 μmol (TE)/g). The test results confirmed that leaf and flower extracts, even at low concentrations (0.313–0.63%), significantly inhibit the growth of selected Gram-negative and Gram-positive bacteria and Candida yeasts. Inhibition of mold growth was observed at a dose extract of at least 1 mL/100 mL.

Porous wood-based boards, like any lignocellulosic material, are susceptible to biocorrosion caused by mold fungi. Their durability can be extended by using biocides. Due to the fact that porous boards are considered an ecological material, it would be beneficial to also use natural agents to protect them. For this purpose, the surface of softboards was protected with a 30% solution of cinnamon bark oil in ethanol. Three application levels were used: 75 g/m2, 120 g/m2, and 200 g/m2 of solution. It has been shown that the cinnamon bark oil solution used at an application rate of 200 g/m2 is an effective fungicide, protecting softboards (SBs) against the development of mold fungi: T. viride and C. globosum. The dominant volatile component of cinnamon oil identified in the boards turned out to be cinnamaldehyde. Three months after treatment, this substance constituted 74% of the volatile components. The proposed treatment method allows for short-term preventive protection of boards against mold fungi.