The chemical composition of the essential oils from the needles of Pinus ponderosa (north american pine), P. resinosa (red pine) and P. strobus (eastern white pine) has been determined by GC/MS (FID). The essential oils from P. resinosa and P. ponderosa in comparison to P. strobus have been characterized by the higher content of β-pinene (42.4%, 45.7% and 7.9% respectively). On the other hand, α-pinene (17.7%) and germacrene D (12.2%) were dominant compounds of P. strobus. Moreover the essential oil from P. resinosa was more rich in myrcene-15.9%. Estragole and Δ-3-carene, each one in amount ca 8% were identified only in P. ponderosa. The content of essential oils in the needles slightly varied - 0.65% - P. resinosa, 0.4% - P. strobus, 0.3% - P. ponderosa. The antifungal activity has been investigated towards Fusarium culmorum, F. solani and F. poae. The strongest activity was observed for the essential oil from P. ponderosa, which fully inhibited the growth of fungi at the following concentrations - F. culmorum, F. solani at 2% and F. poae at 5%.

In the framework of the correlation between chemotaxonomy and chemical analysis studies, the chemical composition of the essential oils of four varieties of Thuja species cultivated in Poland − T. occidentalis ‘globosa’, T. occidentalis ‘aurea’, T. plicata and T. plicata ‘gracialis’ − were investigated by GC and GC-MS. Thirty-one compounds were identified from T. occidentalis ‘globosa’, representing 96.92% of the total oil; twenty-seven from T. occidentalis ‘aurea’ (94.34%); thirty-one from T. plicata (94.75%); and thirty compounds from T. plicata ‘gracialis’ (96.36%). The main constituents in all samples were the monoterpene ketones α- and β-thujone, fenchone and sabinene, as well as the diterpenes beyerene and rimuene.The chemosystematic value of the total ketone content of all samples (which varied from 54.30–69.18%) has been discussed and investigated. The constituents, beyerene and the mixture of α- and β-thujone, were isolated from the oils and tested against six Gram-positive and -negative bacteria and three pathogenic fungi. The oils of the two T. plicata species exhibited significant antimicrobial activity, while the mixture of α- and β-thujone showed very strong activity as well.

The young shoots of Rubus idaeus are traditionally used as a herbal remedy in common cold, fever and flu-like infections yet there is no research concerning this plant material. The aim of the study was to evaluate the chemical composition and biological properties of raspberry shoots from 11 cultivar varieties.

Raspberries, derived from different cultivar varieties, are a popular ingredient of everyday diet, and their biological activity is a point of interest for researchers. The ethanol–water extracts from four varieties of red (Rubus idaeus ‘Ljulin’, ‘Veten’, ‘Poranna Rosa’) and black (Rubus occidentalis ‘Litacz’) raspberries were evaluated in the range of their antimicrobial properties as well as phenolic content – sanguiin H-6, free ellagic acid and anthocyanins. The antimicrobial assay was performed with the use of fifteen strains of bacteria, both Gram-negative and Gram-positive. The antimicrobial activity of the extracts varied and depended on the analysed strain of bacteria and cultivar variety, with the exception of Helicobacter pylori, towards which the extracts displayed the same growth inhibiting activity. Two human pathogens Corynebacterium diphtheriae and Moraxella catarrhalis proved to be the most sensitive to raspberry extracts. Contrary to the extracts, sanguiin H-6 and ellagic acid were only active against eight and nine bacterial strains, respectively. The determined MIC and MBC values of both compounds were several times lower than the tested extracts. The highest sensitivity of Corynebacterium diphtheriae to extracts from both black and red raspberries may be due to its sensitivity to sanguiin H-6 and ellagic acid.

Staphylococcus aureus is the most common infectious agent involved in the development of skin infections that are associated with antibiotic resistance, such as burn wounds. As drug resistance is a growing problem it is essential to establish novel antimicrobials. Currently, antibiotic resistance in bacteria is successfully controlled by multi-drug therapies. Here we demonstrate that secondary metabolites present in the extract obtained from Drosera binata in vitro cultures are effective antibacterial agents against S. aureus grown in planktonic culture and in biofilm. Moreover, this is the first report demonstrating the synergistic interaction between the D. binata extract and silver nanoparticles (AgNPs), which results in the spectacular enhancement of the observed bactericidal activity, while having no cytotoxic effects on human keratinocytes. Simultaneous use of these two agents in significantly reduced quantities produces the same effect, i.e. by killing 99.9% of bacteria in inoculum or eradicating the staphylococcal biofilm, as higher amounts of the agents used individually. Our data indicates that combining AgNPs with either the D. binata extract or with its pure compound (3-chloroplumbagin) may provide a safe and highly effective alternative to commonly used antibiotics, which are ineffective towards the antibiotic-resistant S. aureus.