Individual stereoisomers of verbenol and verbenone express bioactive features

Exploring Volatiles and Biological Effects of Commiphora africana and Boswellia papyrifera Incense

The resin of Commiphora africana and the resin and bark of Boswellia papyrifera play versatile roles in traditional Sudanese culture, including use in inhalation therapy, liquid remedies, and as chewing gum. Thus, this study aimed to analyze the volatile compounds in these materials using various extraction methods and assess their biological activities. Extraction methods included MonoTrap solid-phase microextraction, smoke solvent trapping, and acetone immersion. Gas chromatography-mass spectrometry analysis of MonoTrap extracts identified highly volatile compounds, while smoke extracts contained compounds with lower volatility. Solvent immersion captured a broader range of compounds. The resin of C. africana was rich in limonene, verbenone, and β-selinene, whereas B. papyrifera extracts contained octyl acetate, trans-nerolidol, and nerolidol isobutyrate as major compounds. Biological assays showed C. africana smoke extract inhibited tyrosinase activity, with p-cymene and S-limonene acting as competitive inhibitors. It also inhibited the growth of cancer cells, A549 and MIA Paca-2, while solvent extracts from both resins inhibited all tested cell lines. Further, the acetone extracts exhibited strong antibacterial activity against Streptococcus mutans. These results highlight the differences in chemical composition between the two species, the impact of extraction methods, and the therapeutic potential of C. africana and B. papyrifera as sources of bioactive compounds.

Indication of the sensitivity of Pinaceae species growing in Eastern Central Europe to ground-level ozone pollution

This study focused on testing the response of the assimilation apparatus of evergreen Pinaceae species to increasing levels of oxidative stress simulated in manipulative experiments. Needles were collected from mature individuals of Pinus mugo, Pinus cembra, Pinus sylvestris, Abies alba, and Picea abies at the foothill (FH) and alpine treeline ecotone (ATE) in the High Tatras (Western Carpathians). The injury index (INX), quantified by the modified electrolyte leakage (EL) method, indicated severe needle damage due to exposure to extremely high levels of O3. Ozonation induced changes in the chemical composition of the needles, which were detected via gas chromatography-mass spectrometry. The oxidative stability (OxS) indicator derived from INXs was used to determine the stomatal O3 flux-based critical level CL(OxS), with the threshold value of OxS at -0.05, corresponding to 5% injury to the needles. Assessment of the phytotoxic ozone dose (POD0) under ambient O3 and field environmental conditions during the 2023 growing season via CL(OxS) revealed that the studied species utilised between 18% (Abies alba FH) and 33% (Pinus mugo ATE) of their O3 tolerance potential. These results support our hypothesis that Pinaceae species growing in the High Tatras, which are part of the Alpine biogeographical region of Eastern Central Europe, are vulnerable to O3 concentrations significantly higher than the typical ambient O3 level in the natural environment.

Antifungal activity of bio-active cell-free culture extracts and volatile organic compounds (VOCs) synthesised by endophytic fungal isolates of Garden Nasturtium

Antimicrobial resistance in fungal pathogens (both human and plant) is increasing alarmingly, leading to massive economic crises. The existing anti-fungal agents are becoming ineffective, and the situation worsens on a logarithmic scale. Novel antifungals from unique natural sources are highly sought to cope sustainably with the situation. Metabolites from endophytic microbes are the best-fitted alternatives in this case. Endophytes are the untapped sources of 'plants' internal microbial population' and are promising sources of effective bio-therapeutic agents. Fungal endophytes were isolated from Tropaeolum majus and checked for antifungal activity against selected plant and human pathogens. Bioactive metabolites were identified through chromatographic techniques. The mode of action of those metabolites was evaluated through various spectroscopic techniques. The production of antifungal metabolite was optimized also. In particular VOCs (volatile organic compounds) of TML9 were tested in vitro for their anti-phytopathogenic activity. Ethyl acetate (EA) extract of cell-free culture components of Colletotrichum aenigma TML3 exhibited broad-spectrum antifungal activity against four species of Candida and the major constituents reported were 6-pentyl-2H-pyran-2-one, 2-Nonanone, 1 propanol 2-amino. The volatile metabolites, trans-ocimene, geraniol, and 4-terpinyl acetate, produced from Curvularia lunata TML9, inhibited the growth of some selected phyto pathogens. EA extract hampered the biofilm formation, minimised the haemolytic effect, and blocked the transformation of Candida albicans (MTCC 4748) from yeast to hyphal form with a Minimum Fungicidal Concentration (MFC) of 200-600 µg mL-1. Central carbohydrate metabolism, ergosterol synthesis, and membrane permeability were adversely affected and caused the lethal leakage of necessary macromolecules of C. albicans. Volatile metabolites inhibited the growth of phytopathogens i.e., Rhizoctonia solani, Alternaria alternata, Botrytis cinerea, Cercospora beticola, Penicillium digitatum, Aspergillus fumigatus, Ceratocystis ulmi, Pythium ultimum up to 89% with an IC50 value of 21.3-69.6 µL 50 mL-1 and caused leakage of soluble proteins and other intracellular molecules. Citrusy sweet odor volatiles of TML9 cultured in wheat-husk minimised the infections of Penicillium digitatum (green mold), in VOC-exposed sweet oranges (Citrus sinensis). Volatile and non-volatile antifungal metabolites of these two T. majus endophytes hold agricultural and pharmaceutical interests. Metabolites of TML3 have strong anti-Candida activity and require further assessment for therapeutic applications. Also, volatile metabolites of TML9 can be further studied as a source of antifungals. The present investigational outcomes bio-prospects the efficacy of fungal endophytes of Garden Nasturtium.

Phytochemical Profiles and Biological Activities of Plant Extracts from Aromatic Plants Cultivated in Cyprus

Medicinal and aromatic plants' properties, still an interesting research area, are attributed to the presence of various specialized products that possess important pharmacological activities. In the present study, six medicinal/aromatic plants (Sideritis cypria, Origanum dubium, Melissa officinalis, Mentha piperita, Thymus capitatus, and Salvia fruticosa) were evaluated for their phytochemical and nutritive composition, as well as their biological activities, including antioxidant, antimicrobial, and cytotoxic properties. The results obtained indicate that M. piperita was rich in proteins and minerals such as N and Mg, while S. cypria accumulated more K, Na, P, and Ca. The highest content of phenols and flavonoids was observed in M. piperita, followed by O. dubium and T. capitatus, which eventually influenced their high antioxidant capacity. NMR screening revealed the presence of (i) triterpenoids and hydroxycinnamic acid derivatives in M. officinalis; (ii) terpenoids, flavonoids, and phenolic acid derivatives in S. fruticosa; (iii) flavonoids and phenolic acid derivatives in M. piperita; (iv) phenolic monoterpenes in O. dubium and T. capitatus; and (v) terpenoids, flavones, and phenylethanoid glycosides in S. cypria. The results of the antimicrobial activity showed that the tested samples overall had quite good antimicrobial potential. High antibacterial activity was found in O. dubium and T. capitatus, while O. dubium and S. cypria exhibited great antifungal activities. The studied species also had an important effect on the viability of female-derived and colon cancer cells. In particular, in colon cancer cells, the extracts from T. capitatus, M. officinalis, M. piperita, and S. fruticosa exhibited a stronger effect on cell viability in the more metastatic cell line at significantly lower concentrations, indicating an important therapeutic potential in targeting highly metastatic tumors. This finding is worth further investigation. The present study unveiled interesting phytochemical profiles and biological properties of the six medicinal/aromatic plants, which should be further explored, contributing to green chemistry and the possible creation of natural health products for humans' health/nutrition and additives in cosmetics.