The chemical composition of propolis of four species of stingless bees (SLBs) from Argentina was determined, and its antibacterial and anticancer activity was evaluated on selected types of microbes and cancer cell lines. Volatile secretions of all propolis samples are formed by 174 C₂–C₁₅ organic compounds, mainly mono- and sesquiterpenes and their derivatives. The chromatograms of ether extracts showed 287 peaks, of which 210 were identified. The most representative groups in the extracts of various propolis samples were diterpenoids (mainly resin acids), triterpenoids and phenolic compounds: long-chain alkenyl phenols, resorcinols and salicylates. The composition of both volatile and extractive compounds turned out to be species-specific; however, in both cases, the pairwise similarity of the propolis of Scaptotrigona postica and Tetragonisca fiebrigi versus that of Tetragona clavipes and Melipona quadrifasciata quadrifasciata was observed, which indicated the similarity of the preferences of the respective species when choosing plant sources of resin. The composition of the studied extracts completely lacked flavonoids and phenolcarboxylic acids, which are usually associated with the biological activity and medicinal properties of propolis. However, tests on selected microbial species and cancer cell lines showed such activity. All propolis samples tested against Paenibacillus larvae, two species of Bacillus and E. coli showed biofilm inhibition unrelated to the inhibition of bacterial growth, leading to a decrease in their pathogenicity. Testing the anticancer activity of ether extracts using five types of cell cultures showed that all four types of propolis studied inhibit the growth of cancer cells in a dose- and time-dependent manner. Propolis harvested by T. clavipes demonstrated the highest cytotoxicity on all tested cell lines.

The decomposition of plant litter, most of which is found in forests, is an important element of the global carbon cycle, as a result of which carbon enters the atmosphere in the form of not only CO₂ but also volatile organic compounds (VOCs). Although the formation of litter is associated with autumn cooling, in the spring, there is a very intense fall of faded inflorescences of woody plants. This study examined the chemical composition of the litter and VOCs emitted from decaying inflorescences of four species of forest-forming trees: silver birch, European hornbeam, black alder and aspen. All litter emissions consisted of 291 VOCs, mainly terpenes actively participating in atmospheric processes. The detection of a number of typical mushroom metabolites, such as 1-octen-3-ol, known as “mushroom alcohol”, and alkyl sulphides, suggests that inflorescence-derived VOCs are a mixture of components of plant and microbial origin. In methanol extracts of the fallen inflorescences of all types, 263 organic compounds were identified, the majority of which were related to carbohydrates. Their share in the extracts was 72–76%. In general, the composition of the extractive compounds indicates the easy availability of this material for assimilation by various types of destructors.

Five Strobilanthes species indigenous to the Kumaun Himalayan region of Uttarakhand, India, have been historically employed in traditional medicine to treat bacterial infections, inflammatory conditions, and respiratory ailments, but remain largely unexplored for aquaculture disease management applications. Dichloromethane extracts of S. glutinosa (SGDE), S. pentastemonoides (SPDE), S. angustifrons (SADE), S. attenuata (SATDE) and S. tomentosa (STDE) were comprehensively analysed by GC‐MS for phytochemical profiling, with antioxidant activity quantified using DPPH radical scavenging and ferrozine‐based metal chelating assays, and antibacterial efficacy evaluated against Aeromonas salmonicida and Edwardsiella tarda using disc diffusion methodology. Pearson correlation analysis, molecular docking, and ADMET computational modelling were performed to elucidate structure‐activity relationships and pharmacokinetic properties. GC‐MS analysis identified 42‐59 phytochemical constituents per species, with sterols and triterpenes constituting the predominant class. STDE demonstrated superior DPPH radical scavenging activity, while SATDE exhibited optimal metal chelating potential. SGDE and STDE displayed the good antibacterial activities against both pathogens. Pearson correlation analysis identified n‐tritriacontane and sclareol associated with antimicrobial activity, while molecular docking revealed superior binding affinities for β‐amirone to DNA topoisomerase I and β‐amyrin. ADMET assessment identified sclareol, stigmasterol, and 24‐epicampesterol as optimal candidates with favorable.

Leaf litter decomposition is a key pathway for carbon transfer from forest ecosystems to soils and surface waters. Dissolved organic matter (DOM) released during early-stage leaching represents a potentially reactive fraction of this carbon pool; however, its molecular composition and short-term reactivity remain insufficiently characterised. This study provides a comparative characterisation of DOM released from composite leaf litter samples representing five common deciduous tree species (Betula pendula, Carpinus betulus, Alnus glutinosa, Populus tremula, and Quercus robur) under controlled laboratory conditions. Leaf material collected from multiple trees per species was pooled to obtain a single composite sample; therefore, replicate leaching experiments represent procedural rather than biological replication. DOM was isolated using solid-phase extraction (SPE) and analysed by gas chromatography–mass spectrometry (GC–MS) following trimethylsilyl (TMS) derivatisation, while chemical oxygen demand (COD) and biochemical oxygen demand (BOD₅) were used as indicators of oxidative reactivity and short-term biodegradability. The applied analytical approach captures a selective and operationally defined fraction of DOM, primarily low-molecular-weight and derivatisable compounds; therefore, the results are interpreted as semi-quantitative compositional fingerprints. Carbohydrates, phenolic compounds, and low-molecular-weight organic acids dominated the detected fraction of DOM, with differences observed among composite samples. The composite samples representing A. glutinosa and P. tremula contained higher relative proportions of carbohydrate-related compounds, whereas the composite samples representing B. pendula and C. betulus showed higher relative contributions of aromatic compounds. Apparent differences in BOD₅ were observed among composite samples; however, these observations likely reflect procedural variability rather than independent biological effects. The results indicate variability in DOM composition and apparent reactivity among composite litter samples under controlled laboratory conditions. Due to the lack of biological replication and the selective nature of the analytical approach, the findings should be interpreted as exploratory and not as evidence of generalised tree-species effects.