Antimicrobial resistance is one of the major global health problems and it’s related to the enormous number of human deaths. The occurrence and severity of infections caused by microbial pathogens illustrate the need for the identification and characterization of novel antimicrobial agents of natural origin. This review discusses a well-known coniferous genus Abies Mill. in terms of antimicrobial potential. Data regarding the antibacterial, antifungal, and antiviral properties of Abies species were collected and summarized in this review. It was found that 13 different Abies species are recognized as potential sources of antimicrobial compounds. The most investigated species was A. spectabilis (syn. A. webbiana), followed by A. alba, A. cilicica, A. sibirica, A. nordmanniana, A. numidica, A. koreana, A. balsamea, A. holophylla, and A. concolor. Individual studies on A. firma, A. beshanzuensis, and A. cephalonica were also taken into account. The largest number of analyzed results were related to the antibacterial activity of Abies-derived products, but studies on antifungal, and particularly antiviral capacity were also noted. The most investigated products were essential oils and extracts. The broadest antimicrobial activity was observed for A. cilicica. This study noted that some endemic and endangered Abies species were being used for antimicrobial purposes. In that term, the rationalization of the sampling practices and the implementation of the conservation activities are of great importance. This review represents a comprehensive overview of the current knowledge on the antimicrobial potential of the genus Abies.

Aims: The aim of this study was to conduct antimicrobial analysis on novel Schiff base-derived cobalt(II) complexes (Co(L1) 2 and Co(L2) 2 )

Amaranthaceae Juss. family encompasses many edible plants with prominent biological activity. This investigation tested the bioactive properties of ethanolic and methanolic extract of three well-known species: spinach (Spinacia oleracea L.), chard (Beta vulgaris L. subsp. vulgaris), and orache (Atriplex hortensis L.) through the determination of total phenolic and flavonoid content, antioxidant activity, and antibacterial properties. The particular goal was to evaluate the antibiofilm potential of extracts and to demarcate concentration-depending changes in the biofilm-forming category of included bacterial strains. The mass of the chard and orache methanolic extracts gained by maceration are lower in comparison to the mass of ethanolic extracts obtained by the Soxhlet method. In the case of spinach, the results are the opposite. All extracts have an antiradical activity that can be attributed to the established amounts of phenols and flavonoids. Total phenolics in dry leaves ranged from 0.09 to 0.44 mg GAE/g dw, and total flavonoids from 0.42 to 1.9 mg RTE/g dw. All investigated extracts performed inhibitory potential in terms of bacterial growth, while there was no bactericidal effect observed. Values of the minimum inhibitory concentration ranged from 125 µg/ml to 500 µg/ml. Overall results suggested orache extracts as the strongest inhibitory agents. Antibiofilm assays showed that examined extracts of spinach, chard, and orache caused changes in the biofilm-forming capacity of investigated bacterial pathogens. Fluctuations in observed biofilm-forming categories after application of extracts were concentration-dependent.

Sweet cherry (Prunus avium L.) stems in the form of infusions and decoctions are traditionally consumed for diuretic and anti-inflammatory purposes. This study aimed to evaluate antimicrobial and antibiofilm activity of ethanolic and methanolic extract made from sweet cherry stems. Extracts are obtained by the Soxhlet extraction and maceration procedures. For the determination of the minimum inhibitory concentration, the broth microdilution method is employed, and the assessment of the microbiocidal activity of the extracts is conducted. The antibiofilm activity was tested through the tissue culture plate method, which also allowed the determination of the biofilm-forming categories of investigated strains. The final step involved the calculation of the biofilm inhibition percentage. Examined extracts with the balanced activity inhibited the growth of all microorganisms, with Gram-negative bacteria being more sensitive in comparison to Gram-positive. The values of the minimum inhibitory concentration were 125 µg/ml, and 250 µg/ml, respectfully. Candida albicans was the most susceptible and the minimum inhibitory concentration of both extracts was 62.50 µg/ml. The microbiocidal activity of the extracts was not recorded. Extracts exhibited different impacts on the biofilm-forming capacity of the investigated microbes, and both inhibition and stimulation effects are noted. The percentage of the biofilm inhibition was from 14.27% to 84.78%, with the highest inhibition recorded for the multidrug-resistant Escherichia coli, treated with the ethanolic extract. Sweet cherry stems are a valuable source of natural bioactive compounds, but their usage in the treatment of microbial infections should be correctly and carefully implemented.

Cotoneaster integerrimus represents a multiploid and facultative apomictic system of widely distributed mountain populations. We used flow cytometry to determine genome size, ploidy level, and reproduction mode variation of the Balkan populations, supplemented by analysis of nuclear microsatellites in order to address: (i) geographic distribution and variation of cytotypes among the populations; (ii) variation of reproduction mode and the frequency of sexuality; (iii) pathways of endosperm formation among the sampled polyploids and their endosperm balance requirements; (iv) genotypic diversity and geographic distribution of clonal lineages of polyploids. The prevalence of apomictic tetraploid cytotype followed by sexual diploids and extremely rare triploids was demonstrated. This prevalence of tetraploids affected the populations’ structure composed from clonal genotypes with varying proportions. The co-occurrence of diploids and tetraploids generated higher cytotype, reproductive mode, and genotypic diversity, but mixed-ploidy sites were extremely rare. The endosperm imbalance facilitates the development and the occurrence of intermediate triploids in mixed-ploidy populations, but also different tetraploid lineages elsewhere with unbalanced endosperm. All these results showed that the South European populations of C. integerrimus have higher levels of cytotype and reproductive diversity compared to the Central European ones. Therefore, the South European populations can be considered as a potential reservoir of regional and global diversity for this species.

Taxus baccata L., yew, is dioecious, small to medium-sized evergreen tree, native to Europe, Africa and Asia, but it is cultivated worldwide because of its ornamental features. It is long known that all parts of yew (except for aril) are toxic, due to the alkaloid taxine. Nevertheless, some parts of yew tree can be used to treat cancer and as antimicrobial agents. Unlike its antibacterial properties, antifungal activity of T. baccata is poorly investigated. In this research, antifungal activity of yew methanolic and aqueous extracts was tested against Candida albicans ATCC 10231, Aspergillus brasiliensis ATCC 16404, and Ascosphaera apis MUCL 30769, through the agar well diffusion method. Leaves, bark and reproductive structures extracts were prepared separately for male and female plants. Unlike the aqueous, methanolic extracts caused variable degree of fungal growth inhibition. The strongest inhibition was observed in the activity of the aril extract against A. brasiliensis and C. albicans, with the activity of the male bark extract against A. apis following close. Considering the emerging multidrug resistance in C. albicans, an interesting finding is the inhibition of this species by all tested methanolic extracts, which is significantly stronger in comparison to the inhibition by standard antimycotic solution. According to the available data, male reproductive structures of this species were not tested earlier for their antifungal activity, and our study showed high level of antifungal activity of methanolic microstrobili extract.           

Three Schiff bases were synthesized by reaction of different benzaldehydes with amino acids. The characterization of these compounds was performed using IR spectroscopy, molecular calculations, thin-layer chromatography, determining the melting point and other physical characteristics. IR spectra for imino groups (C=N), which are characteristic of Schiff bases, show stretching frequency from 1629 to 1654 cm-1. The obtained spectral results were confirmed by molecular calculations using the density functional theory (DFT) and were performed before experimental work. The DFT global chemical reactivity descriptors were calculated and used to predict their relative stability and reactivity of synthesized compounds. The antimicrobial assay of all compounds were screened for Grampositive bacteria species: Staphylococcus aureus ATCC 25923; Methicillin-resistant Staphylococcus aureus: MRSA ATCC 33591; Bacillus subtilis ATCC 6633; and Enterococcus faecalis ATCC 29212, Gram-negative: Salmonella enterica ATCC 31194; Pseudomonas aeruginosa ATCC 9027; Escherichia coli ATCC 25922; Extended Spectrum Beta-Lactamase producing E. coli: ESBL E. coli ATCC 35218, and one yeast Candida albicans ATCC 1023.The highest values of inhibition zones were recorded for compound1, followed by the compound 3, while compound 2 performed inhibitory effect just in case of MRSA. DFT calculations show that antimicrobial activity has a good correlation with chemical reactivity descriptors obtained Schiff bases.