Alkyl Thiocyanurates as Thioester Mimetics. Transthioesterification and Ligation Reactions with High Potential in Dynamic Covalent Chemistry.

Alkyl thiocyanurates, the compounds formed in the SN reaction of thiocyanuric acid and alkyl halides, are susceptible to transthioesterification and ligation with molecules containing cysteamine, analogous to native chemical ligation of thioesters with peptides with an N-terminal cysteine moiety. The ligation is irreversible and results in the formation of mono- and disubstituted products dominantly. Transthioesterification, in contrast, is fully reversible and may be used in constructing dynamic systems. The application of this reactivity in dynamic covalent chemistry has been exemplified by the preparation of a library of mixed thiocyanurates of glutathione and thioglycolic acid with self-assembly abilities and metathesis between thiocyanurates of tris(carboxymethyl) and tris(carboxamidomethyl) catalyzed by MESNa (sodium 2-mercaptoethylsulphonate) or MPAA (4-mercaptophenylacetic acid). Differences in reactivity of thiocyanurates toward cysteamines and thiols has been explained based on conceptual DFT.

Factors affecting deer pressure on forest regeneration: The roles of forest roads, visibility and forage availability.

BACKGROUND: Deer pressure on forest regeneration constitutes a serious problem in commercial forests in the northern hemisphere due to the increase in deer populations. However, other drivers, such as climate, landscape structure and the level of human activity, have a strong influence on deer pressure. The direct, density-related impacts of ungulates on forest regeneration have been well studied, but there is limited empirical evidence related to the indirect factors mentioned above. We conducted a field experiment in three forest divisions in Poland to evaluate the role of a common element of human infrastructure, i.e. small, unpaved forestry roads. Additionally, we assessed the modifying effect of visibility driven by vegetation cover and forage availability. RESULTS: The proximity of unpaved roads affected deer habitat use and foraging behaviour, and limited browsing pressure on regenerating forests. Low visibility and higher winter forage availability increased the probability of tree browsing. We observed different responses to roads in two deer species: red deer avoided roads, while roe deer browsed in the vicinity of roads. CONCLUSIONS: A typical forest network of unpaved roads creates a landscape of fear for red and roe deer, and limits browsing pressure on regenerating forests due to the changes in deer habitat use, activity patterns and foraging behaviour. Knowledge of the factors influencing browsing pressure can help to spatially optimise the application of protective measures for tree seedlings.

Establishment and Maintenance of Power Lines are Important for Insect Diversity in Central Europe.

Open habitats are disappearing from European forests. This is mainly due to various management-related practices, such as afforestation and the maintenance of closed canopy plantation forests. Open forests are also declining as a result of the abandonment of traditional forest use practices and natural succession. The effects of the establishment and maintenance of power lines as highly artificial but open habitats in forests on native insect biodiversity remain relatively poorly investigated. We investigated differences in biodiversity between forests and open habitats under power lines in Poland. Namely, we focused on nine insect taxa using the most suitable methods for data collection, i.e., observation and trapping. The studied habitats were forests used for timber production dominated by Scots pine, which is the most commercially important tree species in Poland. In total, we recorded the presence of more than 400 insect species. We found that butterflies as well as ground beetles were significantly more biodiverse under the power lines compared with the forest interior. Furthermore, jewel beetles, long-horned beetles, weevils and bark beetles, rove beetles and darkling beetles appeared to be more species rich under the power lines, click beetles were indifferent, and only lady-bird beetles appeared to be more abundant in forests. Additionally, ground beetles with a strict affinity for forests were surprisingly not negatively affected by power lines. We highlighted the importance of forest-free areas under power lines for the improvement of native forest biodiversity. Artificial and relatively intensive management activities related to the distribution of electric energy play important roles in creating novel or alternative habitats for many insects. Our paper contributes much to the knowledge about the importance of artificial open areas for the diversity of insects.

Photoactive Liposomal Formulation of PVP-Conjugated Chlorin e6 for Photodynamic Reduction of Atherosclerotic Plaque.

BACKGROUND: Liposomes serve as delivery systems for biologically active compounds. Existing technologies inefficiently encapsulate large hydrophilic macromolecules, such as PVP-conjugated chlorin e6 (Photolon). This photoactive drug has been widely tested for therapeutic applications, including photodynamic reduction of atherosclerotic plaque. METHODS: A novel formulation of Photolon was produced using "gel hydration technology". Its pharmacokinetics was tested in Sus scrofa f. domestica. Its cellular uptake, cytotoxicity, and ability to induce a phototoxic reaction were demonstrated in J774A.1, RAW264.7 macrophages, and vascular smooth muscle (T/G HA-VSMC) as well as in vascular endothelial (HUVEC) cells. RESULTS: Developed liposomes had an average diameter of 124.7 ± 0.6 nm (polydispersity index (PDI) = 0.055) and contained >80% of Photolon). The half-life of formulation in S. scrofa was 20 min with area under the curve (AUC) equal to 14.7. The formulation was noncytotoxic in vitro and was rapidly (10 min) and efficiently accumulated by macrophages, but not T/G HA-VSMC or HUVEC. The accumulated quantity of photosensitizer was sufficient for induction of phototoxicity in J774A.1, but not in T/G HA-VSMC. CONCLUSIONS: Due to the excellent physical and pharmacokinetic properties and selectivity for macrophages, the novel liposomal formulation of Photolon is a promising therapeutic candidate for use in arteriosclerosis treatment when targeting macrophages but not accompanying vascular tissue is critical for effective and safe therapy.

Truffle renaissance in Poland - history, present and prospects.

The use of truffles in Poland has a long tradition, yet due to some historical aspects, this knowledge was lost. Currently, truffles and truffle orchards are again receiving attention, and thanks to, e.g., historical data, they have solid foundations to be established. Publications relating to truffles between 1661 and 2017 were searched for in international and national databases, such as the database of PhD theses, Google Scholar, and catalogues of the National Library of Poland, the Jagiellonian Digital Library, the University Library of J. Giedroyc in Bialystok and the Lower Silesian Digital Library (DBC). A very meticulous survey of the literature on truffles showed that truffles have been known since at least 1661. In the 18th century, the fungi were considered a non-timber forest product. It is interesting to mention the impact of Polish Count Michal Jan Borch in understanding the nature of truffles. The whitish truffle (Tuber borchii) is named after him. The greatest number of publications regarding truffles can be observed at the first half of the 19th and 20th centuries. The fungi were present not only in cookbooks but also in scientific literature, and aspects of their ecology and medicinal use are considered. The "dark ages" for truffles, mainly for social reasons, occurred after the Second World War. In tough times, when Poland was under Soviet communist control (1945-1989), truffles as a luxurious product have been completely forgotten. However, at the end of the 20th century, truffles started receiving attention in Polish society. Yet, the real awakening began in the first decade of the twenty-first century when the first truffle orchards were established. One of them has already produced the first fruit bodies of summer truffle (Tuber aestivum). Truffles have been present in Polish culture for centuries. Their renaissance indicates the need for fostering sustainable agroforestry-centred initiatives aimed at helping truffle growers in growing the precious fungi and thus meeting market demands.

Disparity in elevational shifts of European trees in response to recent climate warming.

Predicting climate-driven changes in plant distribution is crucial for biodiversity conservation and management under recent climate change. Climate warming is expected to induce movement of species upslope and towards higher latitudes. However, the mechanisms and physiological processes behind the altitudinal and latitudinal distribution range of a tree species are complex and depend on each tree species features and vary over ontogenetic stages. We investigated the altitudinal distribution differences between juvenile and adult individuals of seven major European tree species along elevational transects covering a wide latitudinal range from southern Spain (37°N) to northern Sweden (67°N). By comparing juvenile and adult distributions (shifts on the optimum position and the range limits) we assessed the response of species to present climate conditions in relation to previous conditions that prevailed when adults were established. Mean temperature increased by 0.86 °C on average at our sites during the last decade compared with previous 30-year period. Only one of the species studied, Abies alba, matched the expected predictions under the observed warming, with a maximum abundance of juveniles at higher altitudes than adults. Three species, Fagus sylvatica, Picea abies and Pinus sylvestris, showed an opposite pattern while for other three species, such as Quercus ilex, Acer pseudoplatanus and Q. petraea, we were no able to detect changes in distribution. These findings are in contrast with theoretical predictions and show that tree responses to climate change are complex and are obscured not only by other environmental factors but also by internal processes related to ontogeny and demography.