Laurel (Laurus nobilis L.) is a plant species from Lauraceae family, and is native to the Mediterranean region. The goal of this study was to compare chemical composition of laurel leaves and antibacterial activity of its essential oil (EO) from wild-grown trees in Greece and Georgia. The laurel leaves from the two native habitats had dissimilar concentrations of phenolic acids. Of the conjugated flavonols and flavons, kaempferol (1981.3 μg/g) and apigenin (1433.6 μg/g) were the major representatives in the leaves from Greece, while luteolin (839.1 μg/g) and kaempferol (688.1 μg/g) were the major ones in the leaves from Georgia, respectively. The EO content was 1.42% and 4.54% in the leaves from Greece and Georgia, respectively. The main EO constituents of the Greek laurel plants were 1,8-cineole (30.8%), α-terpinyl acetate (14.9%), α-terpineol (8.0%), sabinene (7.9%), and terpinen-4-ol (6.0%). The main EO constituents of the Georgian laurel plants were 1,8-cineole (29.2%), α-terpinyl acetate (22.6%), sabinene (12.2%), and methyleugenol (8.1%). The EO antimicrobial activities against 20 microorganisms were determined. Among the Gram-positive bacteria, the Enterococcus faecalis strain was the most sensitive, followed by Staphylococcus aureus ATCC 6538. Among the Candida species, C. albicans ATCC 10231 was the most sensitive to the laurel leaf EOs.

Dry rose extract (DRE) obtained industrially by aqueous ethanol extraction from R. damascena flowers and its phenolic-enriched fraction, obtained by re-extraction with ethyl acetate (EAE) were the subject of this study. ¹H NMR of DRE allowed the identification and quantitation of fructose and glucose, while the combined use of HPLC-DAD-ESIMS and HPLC-HRMS showed the presence of 14 kaempferol glycosides, 12 quercetin glycosides, 4 phenolic acids and their esters, 4 galloyl glycosides, 7 ellagitannins, and quinic acid. In addition, the structures of 13 of the flavonoid glycosides were further confirmed by NMR. EAE was found to be richer in TPC and TFC and showed better antioxidant activity (DPPH, ABTS, and FRAP) compared to DRE. Both extracts displayed significant activity against Propionibacterium acnes, Staphylococcus aureus, and S. epidermidis, but showed no activity against Candida albicans. Toxicity tests on normal human skin fibroblasts revealed low toxicity for both extracts with stronger effects observed at 24 hours of treatment that were compensated for over the following two days. Human hepatocarcinoma (HepG2) cells exhibited an opposite response after treatment with a concentration above 350 µg/mL for EAE and 500 µg/mL for DRE, showing increased toxicity after the third day of treatment. Lower concentrations were non-toxic and did not significantly affect the cell cycle parameters of either of the cell lines.

The seeds of three varieties of melon (Cucumis melo L.) from Bulgaria were analyzed for their chemical composition and a detailed study of their lipids was carried out. Chemical composition values were as follows: fat content ranged from 41.6 to 44.5%, protein 34.4 to 39.8%, crude fiber 4.5 to 8.5%, carbohydrates 8.2 to 12.7%, soluble sugars 3.7 to 4.2%, and minerals 4.6 to 5.1%. The content of sterols, phospholipids, and tocopherols in the oils was 0.6, 0.7–1.7%, and 435–828 mg/kg, respectively. The major fatty acid in lipids was linoleic (51.1–58.5%), followed by oleic acid (24.8–25.6%). The trilinolein (31.3–32.2%), oleo dilinolein (31.0–34.0%), and palmitoyl dilinolein (14.9–22.3%) have represented 80.0% from the total triglyceride composition of the melon seeds oil. β-Sitosterol predominated in both free and esterified sterols, being, respectively, 52.9–70.8 and 50.4–58.4%. Phosphatidylinositol (24.4–33.9%), phosphatidylcholine (23.0–33.1%), and phosphatidylethanolamine (8.4–17.1%) were the main phospholipids. Palmitic acid (34.4–61.7%) was the major fatty acid of the phospholipids, followed by oleic acid (8.9–27.2%). Linoleic acid (32.7–39.1%) was the main component among the fatty acids of the sterol esters, followed by oleic acid (25.1–30.7%). In the tocopherol fraction of melon seed oils, the main component γ-tocopherol varied from 71.4 to 91.5%.

Gamma irradiation has been applied as an efficient and inexpensive method for the sterilization of nuts for years. However, along with the benefits of such treatment, negative effects are possible because of the formation of reactive oxygen species with a toxic effect on important biologically active substances. Because of the scarce and contradictory information in the literature about gamma-irradiated almonds, the aim of our work was the examination of the lipid changes, antioxidant activity, and oxidative stability of almonds treated by 10 and 25 kGy gamma rays, as well as changes in intensity of the EPR spectra as an indicator for the stability of radiation-induced free radicals. The results revealed no significant differences in the EPR spectra of almonds treated at 10 and 25 kGy doses, neither in their intensity nor in kinetic behaviour. The EPR signals decayed exponentially over 250 days, with a decreasing of central line by 90%, with satellite lines by about 73%. No significant changes in the fat content, fatty acids composition, and acid value of irradiated almonds were observed. However, the amount of (alpha)tocopherols decreased from 292 to 175 mg/kg, whereas the conjugated dienes and trienes increased, K₂₃₂ from 1.3 to 3 and K₂₆₈ from 0.04 to 0.15, respectively, with the increasing of irradiation dose. The same was observed for total polyphenols in defatted almonds (1374 to 1520 mg/100 g), where in vitro antioxidant activity determined by ORAC and HORAC methods increased from 100 to 156 µmol TE/g and from 61 to 86 µmol GAE/g, respectively. The oxidative stability of oil decreased from 6 to 4 h at 120 °C and from 24.6 to 18.6 h at 100 °C (measured by Rancimat equipment). The kinetic parameters characterizing the oxidative stability of oil from 10 kGy irradiated almonds were studied before and after addition of different concentrations of ascorbyl palmitate as a synergist of tocopherols. Its effectiveness was concentration-dependent, and 0.75 mM ensured the same induction period as that of non-irradiated nut oil. Further enrichment with alpha-tocopherol in equimolar ratio with palmitate did not improve the oil stability. In conclusion, gamma irradiation is an appropriate method for the treatment of almonds without significant changes in fat content and fatty acids composition. The decreasing of oxidative stability after higher irradiation could be prevented by the addition of ascorbyl palmitate.

The chemical composition of Vitex agnus-castus L. (Verbenaceae family) fruits, collected from two regions in Bulgaria (south-central and north-east Bulgaria), was investigated. The content of proteins (5.3–7.4%), carbohydrates (73.9–78.8%), fiber (47.2–49.9%), ash (2.5–3.0%), essential oils (0.5%), and vegetable oil (3.8–5.0%) were identified in the fruits. The composition of the essential oils (EOs) of Vitex fruits from both regions was determined; the main compounds were 1,8-cineole (16.9–18.8%), α-pinene (7.2–16.6%), sabinene (6.7–14.5%), and bicyclogermacrene (7.3–9.0%), but significant differences in the quantitative and qualitative composition of EOs between the regions were found. The EOs of plants from north-east Bulgaria demonstrated antimicrobial activity against the pathogenic species Salmonella abony, Staphylococcus aureus, and Bacillus subtilis, but the Gram-negative bacteria Esсherichia coli and Pseudomonas aeruginosa exhibited resistance to the oil. Linoleic acid predominated in vegetable oil from both regions, followed by oleic acid. β-sitosterol and γ-tocopherol were the main components in the sterol and tocopherol fraction of the lipids. Phosphatidic acids were the main components in the vegetable oil from north-east Bulgaria, while in the vegetable oil from south-central Bulgaria, all phospholipids were found in almost the same quantity. Overall, significant differences were observed in the chemical composition (proteins, carbohydrates, ash and moisture) of the fruits from the two regions of Bulgaria, as well as in the content of the main components of their essential and vegetable oils.