Phenological Variations in the Content of Polyphenols and Triterpenoids in Epilobium angustifolium Herb Originating from Ukraine.

The composition of secondary metabolites undergoes significant changes in plants depending on the growth phase and the influence of environmental factors. Therefore, it is important to determine the harvesting time of plant material for the optimum secondary metabolite profile and therapeutic activity of the primary material. The shoots of Epilobium angustifolium are used as a healing tea due to the presence of polyphenolic compounds. The aim of this study was to assess the composition of phenolic compounds and triterpenoid saponins in E. angustifolium leaves and flowers and to estimate the dynamics of their content depending on the flowering phase. Qualitative and quantitative characterisation of polyphenols and triterpenoids in E. angustifolium samples from Ukraine of three flowering phases were performed using the high-performance liquid chromatography photo diode array (HPLC-PDA) method. During the present study, 13 polyphenolic compounds and seven triterpenoids were identified in the plant material. It was noted that the largest content and the best polyphenol profile was in late flowering. The most important polyphenolic compounds in the plant material were chlorogenic acid, hyperoside, isoquercitin, and oenothein B. The triterpenoid profile was at its maximum during mass flowering, with corosolic and ursolic acids being the dominant metabolites. The results of the analysis revealed that the quantity of many of the tested metabolites in the raw material of E. angustifolium is dependent on the plant organ and flowering phase. The largest content of most metabolites in the leaves was in late flowering. In the flowers, the quantity of the metabolites studied was more variable, but decreased during mass flowering and increased significantly again in late flowering. The results show that E. angustifolium raw material is a potential source of oenothein B and triterpenoids.

Do Reproductive Traits of Invasive Populations of Scotch Broom, Cytisus scoparius (Fabaceae), Outperform Native Populations?

Reproductive traits are among the most important factors in determining the success of species establishment and invasion in a new area. Studies on transcontinental invasions have revealed that invasive species perform better in the invasive range than in their native ranges. We assumed that the same regularity exists in intracontinental invasions and thus investigated whether the reproductive traits of Scotch broom, Cytisus scoparius, perform better in the alien invasive range in Europe compared to its native range in the same continent. The aim of this research was to reveal the potential and realised fecundity of C. scoparius in its native and invasive ranges, as well as relationships with the size of pods, habitat type, and how these traits vary at the same site in different years. The results of this study were not able to unambiguously confirm our hypothesis that C. scoparius in the invasive range in Lithuania, specifically in the southern part of the Boreal biogeographical region, outperform plants in the native range with regard to the analysed reproductive traits. Potential fecundity of C. scoparius in the native range was significantly higher than in the invaded range; however, realised fecundity was not significantly different between the native and invasive ranges. The pod length was similar in both ranges, whereas the pod width was significantly greater in the invasive range than in the native range. The results suggest that the number of ovules per pod, number of matured seeds, and the size of pods are related with the type of habitat and local environmental conditions in the habitat. Although many studies on other species have confirmed higher fecundity and overall better performance of plants in the invasive range than in the native range on other continents, this rule probably cannot be applied for intracontinental invasive species occurring in relatively close geographical regions to their native ranges.

Study on the Rare Semiaquatic Plant Elatine hydropiper (Elatinaceae) in Lithuania: Population Density, Seed Bank and Conservation Challenges.

BACKGROUND: Wet, intermittently flooded freshwater coastal and shallow water habitats are notable for their high biodiversity. Many of the usually semiaquatic annuals or small perennials common in such habitats are in decline due to the high sensitivity of such habitats to changes caused by anthropogenic and natural factors. The Euro-Siberian semiaquatic Elatine hydropiper rarely occurs in Lithuania and is protected there and in other Baltic and Central European countries. In 2020, we found a large population of Elatine hydropiper in southern Lithuania (Varena district) in Lake Pabezninkai and its exposed shores. The water level of the lake has receded by about 1.5-1.6 m since 2018, exposing wide, wet, and sandy or silty shores. The aim of this study was to determine the status of the Elatine hydropiper population and to assess its potential for long-term survival. The objectives of the study were to (a) determine the size and quantitative characteristics of the population, (b) assess the seed bank in the shallows and exposed shores of the lake, (c) assess the species diversity in the communities with Elatine hydropiper, (d) evaluate the conservation value of the studied species and the lake habitat. METHODS: The studies were carried out between 2020 and 2021. The number and coverage of plant patches as well as seed bank studies were carried out at three sites with different shoreline substrate. At each site, the number of patches and coverage was assessed in 50 sample plots of 100 cm2. The seed bank was examined in the top 5 cm of the substrate. A total of 90 substrate samples were analyzed. RESULTS: We found that Elatine hydropiper grows on ca. 0.38 ha in the lake and on ca. 0.95 ha on the shores. On the exposed shores, the mean number of Elatine hydropiper patches per 1 m2 was 2155 ± 1241.5 and their mean cover was 23.17% of the surface. Seed bank analyses revealed that the seeds and seed shells were significantly more abundant in the bottom sediments than in the shore sand or silt. The mean number of seeds per liter of soil was 85.8 ± 210.2, and the mean number of seed shells was 217.0 ± 265.8. CONCLUSIONS: The assessment of the status of the species in Lithuania according to the IUCN (International Union for Conservation of Nature) criteria has led us to conclude that it should now be classified as vulnerable [A3; B1ab(iii); C2a(ii); D2]. The key to protecting Elatine hydropiper and other co-occurring rare species with similar ecological and biological characteristics, as well as the plant communities of shallows and exposed wet banks, is to protect their habitats. The survival of the species and their habitats could be assured by recurring significant water level fluctuations in the lake, resulting in periodic emergence of patches of wet sand or silt free from perennial vegetation.

Scirpus radicans (Cyperaceae), a newly-discovered native species in Lithuania: population, habitats and threats.

A previously unrecorded native species, Scirpus radicans (Cyperaceae), was discovered in the southern part of Lithuania in 2020. Although this species has a large distribution area in other parts of Eurasia, it is currently recognised as threatened in many European countries. Recordings of S. radicans in Lithuania had been expected, as these plants do occur or have been reported to occur in neighbouring regions. The aim of this study was to analyse the distribution of S. radicans in southern Lithuania, to determine the occupied areas and the size of populations, to study their capacity of vegetative reproduction, their habitats and associated plant communities, as well as to perform an assessment of the species' conservation status within the country. We studied S. radicans populations at two sites on the shores of Lake Pabezninkai and of Lake Netecius in the Varena District (southern Lithuania), from August to October 2020. A total of 993 individuals of S. radicans were counted and their stands comprised 0.73 ha. The density of individuals in the studied plots ranged from 0.02 to 0.78 plants/m2. Only 0.5% of individuals at Lake Pabezninkai and 20.7% of individuals at Lake Netecius were at the stage of generative reproduction. Individuals at the stage of vegetative reproduction comprised 56.4%, whereas generative individuals amounted to 1.7% of all studied plants. One to seven stolons developed per plant and the mean number of rosettes per stolon was 2.8 ± 1.2. Potentially, a total of ca. 2860 rosettes could be expected from all individuals of the studied plots, but the actual realised rate of vegetative reproduction is unknown. A more detailed study of the reproductive capacities of S. radicans would be required for better understanding the causes of the lately observed decrease of this species in most of the countries of Central Europe. Our analysis of the associated plant communities has enabled us to confirm the presence of a Scirpetus radicantis Nowinski 1930 association previously not recorded in Lithuania. By assessing S. radicans in accordance with the IUCN Criteria, we conclude that this species should be classified as endangered (EN) in Lithuania. Based on this assessment, we propose to include this species on the list of legally protected species of Lithuania. Conservation of shallow lakes with sandy or muddy shores and with significant natural fluctuations of the water level is the main measure for ensuring the survival of S. radicans, as well as other rare and endangered species adapted to such a type of habitat.

The Comparative Analysis of Carboxylic Acid Composition of Four Iris Species from Ukraine.

The present article reports results of analysis of carboxylic acids in leaves of Iris species from Ukraine using a gas chromatography (GC) method with mass spectrometric (MS) detection (GC/MS). Carboxylic acids play significant roles in contemporary society as evidenced by multiple applications in fields of medicine, agriculture, pharmacy, food, and other industries. Study of natural plant products as a source of organic acids is of particular interest. Carboxylic acid composition of leaves of Iris hungarica Waldst. & Kit., Iris germanica L., Iris pallida Lam., and Iris variegate L. was studied for the first time applying GC/MS method. The mass spectrums of compounds were matched with NIST and WILEY Libraries. The GC/MS analysis revealed the presence of 26 common acids in the plant raw materials studied. The short-chain carboxylic acids, such as citric (1337.5-12364.4 mg/kg), malic (50.8-4558.0 mg/kg) and oxalic (1199.0-3435.2 mg/kg) acids were contained in significantly high quantity in all samples. Ferulic, p-coumaric and vanillic acids were the most abundant among phenolic acids. α-Linolenic acid was dominant in the leaves of I. germanica (869.5 mg/kg), I. pallida (753.3 mg/kg), and I. variegate (250.3 mg/kg) among polyunsaturated fatty acids, however, linoleic acid prevailed in the plant raw material of I. hungarica (1150.7 mg/kg). Since the leaves of Iris species studied contain carboxylic acids with diverse pharmacological activity, extracts of these raw materials are perspective for development food supplements and medicines.

Chemical Composition and Antiproliferative Effect of Essential Oils of Four Solidago Species (S. canadensis, S. gigantea, S. virgaurea and S.×niederederi).

There is a growing interest in the research of natural products with potent activity in the prevention and treatment of diseases. Thereby, essential oil phytochemicals have demonstrated broad bioactivities. This study highlights the chemical composition of essential oils obtained from the leaves and inflorescences of diverse species of the genus Solidago (Solidago canadensis, Solidago gigantea, Solidago virgaurea and Solidago×niederederi), also known as Goldenrod, through GC/MS analysis, and their antiproliferative activity on three human tumor cell lines (MDA-MB 231, A375 and HCT116) by the MTT assay. The most represented chemical classes in the essential oils were oxygenated sesquiterpenes, sesquiterpene hydrocarbons, oxygenated monoterpenes and monoterpene hydrocarbons, with a remarkable contribution of compounds such as germacrene D (3.89-19.51 %), α-pinene (3.59-18.82 %), bornyl acetate (3.30-12.73 %) and caryophyllene oxide (3.07-9.18 %). Chemical quali- and quantitative differences were noticed between the leaves and flowers of the same species, as well as between the studied species. The MTT assay showed that the essential oils from the leaves were more active than those from the flower ones. The essential oil having the highest impact on cell viability was that from S.×niederederi (IC50 =12.93, 6.72, and 6.82 µg/ml), followed by S. virgaurea (IC50 =13.39, 7.96, and 8.36 µg/ml) and finally S. gigantea (IC50 =18.04, 5.94, and 8.10 µg/ml) on MDA-MB 231, A375 and HCT116 cell lines, respectively. The essential oil from S. canadensis showed the lowest activity (IC50 =29.33, 12.63, and 18.03 µg/ml, respectively). Taken together, these findings highlight the Solidago species as good sources of cytotoxic compounds. Further studies are encouraged on the in vivo effects and safety of these products.

Effect of ecological factors on the accumulation of phenolic compounds in Iris species from Latvia, Lithuania and Ukraine.

INTRODUCTION: It is important to conduct studies on the influence of environmental factors on the accumulation of secondary metabolites in plants, as well as the cultivation of plants and harvesting of their raw material. OBJECTIVE: In this study, we examined the influence of habitat types, soil composition, climatic factors and altitude on the content of phenolic compounds in Iris species from different populations in Latvia, Lithuania and Ukraine. METHODOLOGY: According to high-performance liquid chromatography (HPLC) analysis, 25 compounds (flavonoids, isoflavonoids, isoflavonoid glucosides, xanthones, phenolcarboxylic acids) were identified in the methanol extracts of 16 samples of Iris rhizomes. The quantitative data were further analysed by principal component analysis (PCA) to reveal the impact of environmental factors on the accumulation of compounds in plants. RESULTS: Iris pseudacorus from Latvia and Lithuania had a more diverse composition of phenolic compounds than samples from Ukraine. Sampled plants of the Iris subg. Iris had a higher content of the analysed compounds than those of Iris subg. Limniris. PCA results showed that the levels of phenolic compounds in Iris rhizomes were influenced by the content of soil nutrients. The phosphorus and potassium content had a significant impact on the levels of phenolic compounds, whereas the impact of nitrogen content was not significant. Meteorological factors had a small impact; however, sunshine duration had a significant positive effect and the amount of precipitation had a significant negative impact. CONCLUSION: The results of this study suggest that rhizomes of Iris species may be an important source of pharmacologically active compounds such as flavonoids, isoflavonoids and xanthones. Studies on the effect of environmental factors on the production and accumulation of secondary metabolites in Iris species are important because they contribute to knowledge of quantitative parameters of secondary metabolites in medicinal plants and could be employed for the cultivation and harvesting of raw material for medicinal purposes.

Asclepiasspeciosa (Apocynaceae, Asclepiadoideae): a rare or unrecognized alien species in Europe?

Studies on populations of Asclepiassyriaca L. in Lithuania revealed the occurrence of a new alien plant species, the North American native Asclepiasspeciosa Torr. (Apocynaceae, Asclepiadoideae), in southern parts of Lithuania - the first report of the latter species in Europe. Interestingly, a thorough analysis of herbarium specimens revealed that A.speciosa had first been collected in Lithuania in 1962, but the specimen was misidentified at the time as A.syriaca. The newly discovered population of A.speciosa occupies mesic grasslands, tall-herb fringe communities and arable field habitats. Sexual reproduction of this species was not recorded; it spreads locally by means of vegetative reproduction. We present here an exhaustive analysis of morphological characteristics and differences between A.speciosa and A.syriaca and other species of the genus, as well as a key for identification of alien Asclepias species in Europe. We predict that the effect of A.speciosa on native habitats and communities, and its economic impact, are comparable to those of the highly invasive A.syriaca. Although A.speciosa currently occurs very rarely as an alien species in Europe, its existence in other regions of Europe is highly probable.