Milica Rat

Biochemical Characterization of Helichrysum italicum (Roth) G.Don subsp. italicum (Asteraceae) from Montenegro: Phytochemical Screening, Chemotaxonomy, and Antioxidant Properties

The chemical composition and antioxidant properties of the essential oil and EtOH extract of immortelle (Helichrysum italicum (Roth) G.Don subsp. italicum, Asteraceae) collected in Montenegro were evaluated. The essential oil was characterized by GC/MS analysis, and the content of total phenolics and flavonoids in the EtOH extract was determined using the FolinCiocalteu reagent. The free‐radical‐scavenging capacity (RSC) of both the essential oil and the EtOH extract was assessed with the 2,2‐diphenyl‐1‐pycrylhydrazyl (DPPH) method. Moreover, the inhibition of hydroxyl radical (.OH) generation by the EtOH extract of immortelle was evaluated for the first time here. Neryl acetate (28.2%) and γ‐curcumene (18.8%) were the main compounds in the essential oil, followed by neryl propionate (9.1%) and ar‐curcumene (8.3%). The chemical composition of the oils of the examined and additional 16 selected Helichrysum italicum taxa described in literature were compared using principal component (PCA) and cluster (CA) analyses. The results of the statistical analyses implied the occurrence of at least four different main and three subchemotypes of essential oils. Considering the antioxidant properties, the EtOH extract of immortelle exhibited similar potential as propyl gallate and quercetin, while the essential oil exhibited relatively weak DPPH.‐scavenging capacity.

Alien invasive neophytes of the Southeastern part of the Pannonian Plain

Floristic diversity in the Pannonian Plain is the result of mosaic habitat composition, characterized by steppes, saline meadows, and lowland forests along major rivers. In the last few centuries, the flora has become enriched by species introduced by human activities, such as colonization and industrialization. Presently it consists of nearly 1800 species. As a result of 30 years of field research as well as herbarium and literature searches, a list of invasive alien neophytes has been compiled and is presented here. The list includes 152 species, classified as either naturalized, casual, or unknown. One of the species is listed in Red Book of Serbian Flora. Eighty species are naturalized, and 61 are casual species. The majority of the introduced flora originates from North America (66) and the Old World (43). Most alien invasive species of the Southeastern part of the Pannonian Plain, were introduced accidentally by seed material or deliberately by nursery saplings. The annual and perennial herbaceous plants, which flower in the summer and summer-autumn periods, are represented in the greatest numbers. The alien flora was further analyzed with respect to taxonomy, life forms, pollination, and seed dispersal mode. The greatest number of alien species appears in anthropogenic and semi-natural habitats (59). In natural habitats, 45 invasive taxa were recorded, representing a conservation threat to biodiversity.

Ecologically and ontogenetically induced variations in phenolic compounds and biological activities of Hypericum maculatum subsp. maculatum, Hypericaceae

Numerous traditional and clinically approved indications have created constant raise of demand for Hyperici herba in the world. However, the quality of the plant material depends on the plant source and abiotic factors of the habitats. The scope of the research was to find out whether other Hypericum species have similar chemical characteristics for potential medical use. Hypericum maculatum Crantz is in some Pharmacopoeias listed together with Hypericum perforatum L. as biological source of H. herba, because of similar chemical composition. Often the full taxonomic identification stating the used subspecies of H. maculatum is being avoided. Therefore, the aim of study was to chemically characterize water–alcoholic extracts of subspecies Hypericum maculatum Crantz subsp. maculatum. The samples were collected at three localities, with different habitat characteristics during three ontogenetic phases. The amounts of total phenolics and flavonoids were estimated, as well as the amounts of ferulic and chlorogenic acid, rutin, quercitrin, amentoflavone, apigenin, hypericin, and hyperforin. Chemical composition and ecological characteristics were analyzed by PCA methods. Source of sunlight and soil acidity were shown as ecological factors that potentially could be cause for chemical profiling of samples. Biological potential of extracts was estimated through antioxidant assays and inhibition of acetylcholinesterase (AChE) and α-amylase with the aim to explore potential use of plant in the treatments of diabetes and Alzheimer’s disease. All the extracts exhibited notable antioxidant potential in the used test systems as well as the ability to inhibit AChE and α-amylase. H. maculatum subsp. maculatum exhibits notable correspondence in chemical composition and biological activity with H. perforatum.

Urban flora in the Southeast Europe and its correlation with urbanization

Many studies have refuted the opinion that urban floras are poor in total species number and characterized primarily by neophytes. Also, it has been proved that urban flora differs from its surroundings, and at the same time reflects its richness. Our study focused on urban flora, structure and similarities, and the possible correlation with the urban attributes. Therefore, we selected 11 cities in Southeast Europe, which differ in the development of transportation networks (roads, rails and inland waterways) and population size. Next, we compared two sets of data (structure of urban flora and urban attributes) to define the correlation patterns. Analyzed urban floras were primarily distinguished by a total number of species, number of unique species and neophytes. Belgrade is a city with the highest urbanization level, the most species and the highest number of unique species and neophytes as well. Kosovska Mitrovica, Grocka and Požarevac stand out by floristic richness. These cities have a high number of species, yet a small proportion of neophytes. Other cities are characterized by similar floristic structure, with a relatively similar proportion of neophytes and approximately similar number of unique species in relation to the total number. It can be concluded that other factors beside the chosen urban attributes have additional effects on floristic structure, except for the factor - the presence of neophytes. This is in accordance with predefining subjects, since urban attributes were chosen based on knowledge about important corridors for invasive species.

Deceptive taxonomic importance of the Ornithogalum (Asparagaceae) seed morphology

Ornithogalum taxonomy is under constant revision. Numerous studies relating to morphology, anatomy, cytology, seed micromorphology and molecular phylogenies have been published to date, yet the number of species within the genus continues to be debated. In the Mediterranean region and rest of Europe, the genus comprises c. 120 species that share many common characters. In published resources, seed morphology has mostly been designated as species specific, having low taxonomic value for higher systematics. However, our comparative review of the published data and additional comparative analyses of seed morphology, detailed here, has revealed some discrepancies and limitations in species identifications. Our study included 14 Ornithogalum species, sampled from the Balkan Peninsula and Pannonian Plain. The main aims of the study were to describe seed structure characteristics, determine features upon which species could be identified, and examine the taxonomic relevance of differentiating characteristics. We confirm considerable variability in seed dimensions and shape. Testa primary structure exhibits non-species-specific features and we identify secondary testa structure as being an additional parameter for seed description. Overall, we found that while it is possible to define particular seed morphology patterns, they are of limited value in the taxonomy of this genus.

The Phenolics of the Ornithogalum umbellatum L. (Hyacinthaceae): Phytochemical and Ecological Characterization.

Ornithogalum umbellatum L. is a widely distributed species in Europe, that exhibits considerable variability at ecological, morphological, anatomical, and karyological level. Previous reports of the chemical investigations among Ornithogalum species indicate significant diversity of the secondary metabolites, as well. Knowing that environment affects the phenolic composition in plants to a large extent, the main objective of the research was to define relationship between phytochemical and ecological characters. To estimate an environmental influence on these results, plant material was collected at four habitats that differ in ecological factors and belong to two biogeographical regions: the Balkan Peninsula and the Pannonian Plane. Measured phytochemical characters are yield of dry extract, total phenolic and flavonoid contents, the presence of selected phenolic compounds as well as free‐radical scavenging activity (neutralization of DPPH and OH radicals). Results revealed that all analyzed phytochemical parameters differ between investigated O. umbellatum samples. The moisture level of habitat has the highest correlation, either positive or negative, with most of phytochemical characters, and is followed by temperature and soil reaction. Light intensity and nitrogen level have mostly moderate correlation coefficient with phytochemical characters. More complex correlation is revealed between ecological factors and nine phenolic compounds, with three observed patterns of relationship.

Highly invasive alien plant Reynoutria japonica Houtt. represents a novel source for pharmaceutical industry – evidence from phenolic profile and biological activity

Reynoutria japonica is on the IUCN list of the Worlds’100 worst invasive species, but it is also, especially its rhizome, an integral part of Traditional Chinese Medicine. The objective of this study was to determine the amount of selected phenolic compounds in rhizome, stems, leaves and inflorescence methanol extracts of this plant, their antioxidant and anticholinesterase activity. The chemical profile of the examined extracts was obtained by a high-performance liquid chromatography. In vitro assays on DPPH, OH and NO radicals were used to estimate antioxidant potential and Ellman’s method was applied for the determination of anticholinesterase activity. Leaves and rhizome extracts were found to be rich in rosmarinic and chlorogenic acid, and selected flavonoids. Resveratrol was exclusively present in rhizome and stems extracts. All the investigated extracts expressed certain antioxidant activity, where leaves extract was the most active. However, rhizome extract was the strongest inhibitor of acetylcholinesterase. These findings indicate that there is a possibility of R. japonica exploitation for the isolation of biologically active phenolic compounds used in pharmaceutical and food industry.

Anatomical characteristics of two Ornithogalum L. (Hyacinthaceae) taxa from Serbia and Hungary and their taxonomic implication

Abstract Anatomical characters of two morphologically similar Ornithogalum taxa, O. umbellatum and O. divergens, were investigated. An analysis of leaf and scapus cross-sections was performed on plants from ten populations from Serbia and Hungary, using light microscopy. The aim of this research was to give data about the qualitative and quantitative anatomical characteristics of these taxa, in order to evaluate their taxonomic significance and single out distinctive anatomical features, as well as to contribute to the knowledge of the genus Ornithogalum in the studied region. On the basis of the variability of anatomical characters, similar populations formed two clusters, joining the plants previously determined as O. divergens and O. umbellatum. The two taxa significantly differed for most of the quantitative leaf and scapus characters. Since only quantitative differences were recorded in this research, anatomical characters could not be solely used to separate these two taxa. However, the results of anatomical investigations are consistent with the results of previous morphological and genetic analyses; therefore anatomical parameters could be useful as additional taxonomic characters.