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

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe

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

Amino acid profiling in wild Chamaenerion angustifolium populations applying chemometric analysis /

Evaluation of the amino acid composition of plants is a determining parameter in assessing their potential effect as food supplements. Chamaenerion angustifolium (Onagraceae), commonly known as “fireweed,” is a traditional food and medicinal plant in Europe. Current research has focused on comparative analysis of the aerial part of 15 fireweed samples collected in Ukraine and Lithuania using Gas chromatography–mass spectrometry (GC-MS) method. The overall amino acid composition in samples of C. angustifolium was similar. Sulfur-containing amino acids (cysteine and methionine) were absent in all samples. The alanine content in the samples was the highest, and in the samples from Kharkiv (Ukraine), Ivano-Frankivsk (Ukraine), and Plungė district (Lithuania), it ranked first among others (its content in samples was 2.350, 6.090, and 2.44 mg/g, respectively). The high amount of free amino acids was recorded in the sample from Ivano-Frankivsk (Ukraine). The results of chemometric analysis indicated L-alanine and L-phenylalanine could be used as potential quality markers for the evaluation of the plant quality. The results indicate the potential for further pharmacological studies of fireweed raw material. Considering the content of amino acids in the aerial parts of C. angustifolium, its raw material could be used for development of medicines and dietary supplements

Differences in spatial versus temporal reaction norms for spring and autumn phenological events

For species to stay temporally tuned to their environment, they use cues such as the accumulation of degree-days. The relationships between the timing of a phenological event in a population and its environmental cue can be described by a population-level reaction norm. Variation in reaction norms along environmental gradients may either intensify the environmental effects on timing (cogradient variation) or attenuate the effects (countergradient variation). To resolve spatial and seasonal variation in species' response, we use a unique dataset of 91 taxa and 178 phenological events observed across a network of 472 monitoring sites, spread across the nations of the former Soviet Union. We show that compared to local rates of advancement of phenological events with the advancement of temperature-related cues (i.e., variation within site over years), spatial variation in reaction norms tend to accentuate responses in spring (cogradient variation) and attenuate them in autumn (countergradient variation). As a result, among-population variation in the timing of events is greater in spring and less in autumn than if all populations followed the same reaction norm regardless of location. Despite such signs of local adaptation, overall phenotypic plasticity was not sufficient for phenological events to keep exact pace with their cues-the earlier the year, the more did the timing of the phenological event lag behind the timing of the cue. Overall, these patterns suggest that differences in the spatial versus temporal reaction norms will affect species' response to climate change in opposite ways in spring and autumn