Rumen Mladenov

Rumen Mladenov
Plovdiv University "Paisii Hilendarski" · Department of Botany and Biology for Teachers

PhD

About

82
Publications
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567
Citations
Citations since 2016
36 Research Items
349 Citations
20162017201820192020202120220204060
20162017201820192020202120220204060
20162017201820192020202120220204060
20162017201820192020202120220204060

Publications

Publications (82)
Article
Full-text available
Extracts obtained from different Betonica species have been shown to possess important biological properties. The present study aimed to investigate the cytotoxicity, antitumor and immunomodulatory potential of the endemic plant Betonica bulgarica (Lamiaceae) and thus, reveal new aspects of its biological activity. Methods: Methanolic extract obtai...
Article
Full-text available
Betonica bulgarica is an endemic species distributed in Bulgaria. The chemical composition of the essential oil analysed by GC–MS (Gas chromatography–mass spectrometry) and the content of trace elements analysed by ICP–MS (Inductively coupled plasma mass spectrometry) were determined. Additionally, a study on the types and distribution of trichomes...
Article
Full-text available
Until now, the interest to plants from genus Scutellaria in Bulgaria has been focused mainly on the terpenes in them. The purpose of this study is to enrich the information on the composition of the Bulgarian Scutellaria species in terms of both polyphenolic content as well as primary metabolites such as mono-, oligosaccharides and organic acids. A...
Article
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As producers of biomass, cyanobacteria are a major part of the phytoplankton in a large number of water basins. Due to the cyanobacterial blooms and cyanotoxins produced, these organisms are recognized as a threat and ecological risk for water bodies. Released cyanotoxins may cause death of many organisms including birds and fish. Vaya Lake is the...
Article
Full-text available
Cyanobacteria are the most primitive photosynthetic organisms on the Earth. Their classification is traditionally based on morphological characters in both botanical and bacteriological systems. Due to the enormous diversity and the lack of clear diacritic morphological features between the closely related species, for resolving the evolutionary re...
Article
Full-text available
The present work presents a comparative anatomical study of the leaf epidermis of the Bulgarian endemic Micromeria frivaldszkyana (Degen) Velen. and Clinopodium vulgare L., belonging to the family Lamiaceae. In both species they occur diacytic and anomocytic stomatal type, while the indumentum is presented by multicellular, linear covering trichome...
Article
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The two-year study on the species composition of higher plants was conducted in three moisture zones in the Maritsa river valley, Bulgaria: "Rice-field Plovdiv", protected zone (PZ) "Rice-field Tsalapitsa" and protected area (PA) "Martvitsata Zlato Pole". The analysis was done, using the floristic methods. There were 154 species of vascular plants...
Article
Full-text available
Lingonberry fruits are known to be a rich source of natural compounds which provide many health benefits. Polyphenol-rich extracts from lingonber-ries were tested for their ability to inhibit α-amylase. The inhibitory activity of dietary polyphenols in lingonberry extracts towards α-amylase offers the possibility to modulate the absorption of sugar...
Article
Full-text available
The floristic composition of vascular plants of three moisture zones, along the river Maritsa-"Rice-field Plovdiv", protected zone (PZ) "Rice-field Tsalapitsa" and protected area (PA) "Martvitsata Zlato Pole", was described in terms of phytogeographic elements, biological spectrum, conservation value and anthropogenic impact. The predominant floris...
Article
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Cyanobacteria are photosynthetic prokaryotes with cosmopolitan distribution. They are major producers of primary biomass and free oxygen in most of the freshwater and marine biomes on the planet. Under certain conditions of the environment, these organisms can evolve massively and cause the so-called "water blooms". Very often these blooms are toxi...
Conference Paper
Cyanobacteria are prokaryotic, photosynthetic organisms with long evolution, cosmopolitan distribution and great biodiversity. Many cyanobacteria produce secondary metabolites with hepatotoxic, neurotoxic or dermatotoxic effects, called cyanotoxins. Bloom-forming cyanobacteria can reach high concentrations in water basins and cause death of fish, b...
Article
Full-text available
This paper presents a comparative pharmacognostic study of three species from Plantago genus (Plantago media L., Plantago major L., Plantago lanceolata L.) and assessment of their antioxidant capacity. First time reported microscopic data of P. media leaves revealed the presence of multicellular covering trichomes, stalked glandular trichomes, anom...
Article
Full-text available
The antioxidant properties of Sideritis scardica have been studied. The activity of the Superoxide dismutase enzyme in the leaf of cultivated plants of Sideritis scardica is determined. A comparative analysis of the enzymatic activity in leaves of naturally grown plants, cultivated and in vitro cultivated plants was made. Higher levels of superoxid...
Conference Paper
Full-text available
Cyanobacteria are prokaryotic, photosynthetic organisms with long evolution, cosmopolitan distribution and great biodiversity. Many cyanobacteria produce secondary metabolites with hepatotoxic, neurotoxic or dermatotoxic effects, called cyanotoxins. Bloom-forming cyanobacteria can reach high concentrations in water basins and cause death of fish, b...
Article
Full-text available
Cyanobacteria are unique prokaryotes, which are capable to perform oxygenic photosynthesis. Within these organisms, phycobilisomes (PBS) act as an antenna of the photosynthetic pigment apparatus. Phycobilisomes contain several phycobiliproteins (PBP): phycoerythrin (PE), phycocyanin (PC), allophycocyanin (APC) and phycoerythrocyanin (PEC). The appl...
Article
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The total numerical abundance of phytoplankton, expressed both in individuals and cells, the total biomass, number of species and species diversity, as well as the abundance of the major taxonomic groups were assessed in 18 Bulgarian reservoirs sampled in the summer and autumn of 2016. Eight of those reservoirs have been infested by the zebra musse...
Article
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The biodiversity of genus Carduus in Bulgaria is grossly under-studied with modern methods, which leads to unclear status of species and hampers the assessment of their habitats and conservation status. In this study, we used the variability of internal transcribed spacers (ITS) to investigate the biodiversity of Carduus species collected from diff...
Article
Taxonomy of Cyanobacteria, the oldest phototrophic prokaryotes, is problematic for many years due to their simple morphology, high variability and adaptability to diverse ecological niches. After introduction of the polyphasic approach, which is based on the combination of several criteria (molecular sequencing, morphological and ecological), the w...
Article
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In the current study for the first time were investigated the chemical composition and antioxidant activity of polysaccharides isolated from three indigenous for Bulgaria species of Plantago genus-Plantago major L., Plantago lanceolata L. and Plantago media L. Crude polysaccharides were extracted from fresh leaves with water and dilute acid and the...
Article
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Plantago major L. and Plantago lanceolata L. are medicinal plants with remarkable variety of curative properties: expectorant, diuretic, antispasmodic, antibacterial, antioxidant, antiinflammatory and immunomodulatory. Plantago media L. is a meagerly studied herbaceous plant from Plantago genus. This paper presents a comparative morphological and q...
Article
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The purpose of this review is to examine the botanical characteristics of four species of Vaccinium genus: Vaccinium vitis-idaea L. (Lingonberry), Vaccinium myrtillus L. (Bilberry), Vaccinium uliginosum L. (Bog bilberry) and Vaccinium arctostaphylos L. (Caucasian whortleberry) as well as to consider the chemical composition and therapeutic effects...
Article
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In this study, we investigated the The total phenolic content was determined spectrophotometrically using the Folin-Ciocalteu method. With HPLC analysis, phenolic acid composition of extracts was assessed. Enzymatic inhibitory activities were determined according to the methodology by Borooah et al. (1961), and Dewi et al. (2007). Amyloglucosidase...
Article
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The aim of this paper was to study the correlation between the structure of the water extractable polysaccharides isolated from The hydrolysis reactions were performed with the enzymes hemicellulase and mannanase. Spectrophotometric total reducing sugars assay was used to examine the hydrolysis yield. The monosaccharide and oligosaccharide composit...
Article
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The dynamics of hydrolysis of total acid-extractable polysaccharides from leaves of the medicinal plant Plantago major L. using hemicellulase and xylanase were studied. The degree of polysaccharide hydrolysis and the monomeric units were experimentally determined. Hemicellulase and xylanase hydrolysis both indicated larger amounts of detected monos...
Article
Full-text available
Cyanobacteria comprise oxygenic phototrophic prokaryotes characterized with high diversity of their morphological, physiological and ecological parameters. The enormous diversity makes their classification complicated and currently the polyphasic approach is most applicable. Suitable molecular markers for resolving species or generic level relation...
Article
This study presented pharmacognostic parameters to identify fruits of three wild Vaccinium species from Bulgaria. First time reported microscopic data of Vaccinium vitis-idaea and Vaccinium uliginosum fruits revealed the presence of unicellular, linear covering trichomes, stalked glandular trichomes and anomocytic type ?f stomata. Berry extracts we...
Article
Full-text available
The taxonomical status of blue-green algae (Cyanoprokaryota) is discussing problems because of heterogeneity and polyphyletic in these organisms. A number of cyanoprokaryots are greatly mutable in morphological aspect. Their phenotypical classification is difficult for this reason. Many of the morphological characteristics, which were used for diff...
Article
The current study should be paid extra attention because antibiotics are main cluster of drugs for treatment of child infections and illnesses. They are the most commonly prescribed medicines for children, relatively expensive and consume 60-70% of the budget for treatment of child illnesses, with exclusion only in malign sickness. OBJECT: The curr...
Article
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The study presents data on the diversity of freshwater algal flora on the territory of the Bulgarka Nature Park. One hundred ninety-four species, belonging to 11 divisions were identified. The conservation value of the identified species was assessed.
Article
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Mentha ( Nepetoideae, Lamiaceae ) is a taxonomically complex genus consisting of 29 species and 11 different hybrids including a number of economically important species among them medical plants used for more than 250 years. Because of its high incidence of polyploidy, diverse morphology, high degree of chromosome number variations and interspecie...
Article
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This study reports data on the diversity of bryophytes in the Bulgarka Nature Park. The registered 55 species belonged to 23 families and 46 genera. Six species were with conservation status; 2 were assessed as Not Evaluated. The main threats were assessed and measures towards bryophyte conservation were proposed.
Article
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The study presents data on the diversity of grass species in the region of the village of Mugla (the Western Rhodopes). One hundred forty-one species of higher plants belonging to 40families were registered. (Apiaceae, Aspleniaceae, Asteraceae, Boraginaceae, Brassicaceae,Campanulaceae, Caryophyllaceae, Cistaceae, Cyperaceae, Dipsacaceae, Equisetace...
Article
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A normal-phase High Performance Liquid Chromatography (HPLC) method was developed for the determi- nation of dehydroepiandrosterone (DHEA) in food supplements. We have used an HPLC 200 (Perkin Elmer, USA) with a spectrophotometric detector LC-785A (Bioanalytical systems, USA) and a thermostat (Perkin Elmer, Waltham, MA, USA). We have chosen isocrat...
Article
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The systematics of genus Mentha from the family Lamiaceae of the major group Angiosperms is well known as complicated. It was previously shown that using morphological characters alone is insuficient when differentiating the mint cultivars. It is important to identify and characterize mint species for medical and industrial applications. The presen...
Article
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This study reports data on the diversity of Pteridophyte of the “Bulgarka” Nature Park. Twenty-nine species belonging to the divisions Lycopodiophyta, Equisetophyta and Polypodiophyta were identified, including six new species to the park: Asplenium onopteris, Dryopteris dilatata, Equisetum palustre, Huperzia selago, Ophioglossum vulgatum and Polys...
Article
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Cyanoprokaryotes are widespread organisms, which dominate in different water basins. In the present study, we have investigated the diversity of this group and related physicochemical parameters in 35 standing water basins in Bulgaria. We found 29 cyanoprokaryotic species, which belong to 13 genera from the orders Synechococcales, Spirulinales and...
Article
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This article presents a summary of the research related to the taxonomic composition, algal blooms and toxic potential of representatives from Cyanoprokaryota (Cyanobacteria, Cyanophyta) in the coastal waters of the Bulgarian Black Sea area. Main strands of the algal research, including Cyanoprokaryota, are presented in a chronological order. The t...
Article
Full-text available
This article presents a summary of the research related to the taxonomic composition, algal blooms and toxic potential of representatives from Cyanoprokaryota (Cyanobacteria, Cyanophyta) in the coastal waters of the Bulgarian Black Sea area. Main strands of the algal research, including Cyanoprokaryota, are presented in a chronological order. The t...
Article
Full-text available
Essential oils of Betonica officinalis and Stachys sylvatica obtained by hydrodistillation were analyzed by GC/MS. Sesquiterpene hydrocarbons were dominant in the oils of the studied plant species, growing wild in Bulgaria. The major components in the leaf oil of B. officinalis were: γ-muurolene (19.12%), β-caryophyllene (8.05%), benzaldehyde (7.08...
Article
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The object of investigation is the region of peak Malusha, Kozyata Reka river and the adjacent territories. The studied area is located in the main watershed ridge of the Shipka divide of Central Balkan Range. Identified are 621 species of vascular plants belonging to 355 genera and 88 families. A description of the floristic composition is made. A...
Article
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Over the past decade new ecological indices based on phytoplankton and macrophytes were developed as part of the tools for assessment of the ecological status of water bodies. This study demonstrates the applicability of two of them (Assemblage index /Q/ and Algae Group Index /AGI/) for evaluation of water bodies from a lake type L4 as well as thei...
Conference Paper
Full-text available
A study of the influence of different extracts from Mentha aquatica L. and Mentha longifolia L. on the activity of glycosyltransferase complex from Leuconstoc nesenteroides URE 13 and dextransucrase from Leuconostoc mesenteroides Lm 28 was carried out. The extracts from two plant species showed an inhibitory effect on studied glycosyltransferases a...
Article
Full-text available
Some species of Cyanoprokaryota produce toxins that affect animals and humans. Most of the freshwater basins in Bulgaria, including dams, are relatively well studied in terms of the phytoplankton composition, but the data for presence of cyanotoxins are limited. The aim of our study was to evaluate the diversity, distribution and quantitative devel...
Article
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The legal requirements stated in the EU Water Framework Directive (WFD) have led to increased activity concerning macrophyte indicator metrics in Europe. Nevertheless in Bulgaria such indexes are still under consideration because of the lack of official methodologies. The macrophyte surveys undertaken as a part of two EU-funded projects are a uniqu...
Article
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Research has been carried out of the main characteristics of phytoplankton communities in order to assess the ecological status and ecological potential of the types of lakes in Bulgaria, according to the requirements of WFD 2000/60/EC. Eighty lakes/reservoirs have been researched on the territory of the Republic of Bulgaria. The assessment was mad...
Article
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The study focused on sampling procedures and analysis of biological and physico-chemical quality elements (according to the EU Water Framework Directive (WFD)) and aimed at defining reference conditions and sites, maximum ecological potential, specific physico-chemical and hydromorphological conditions for assessed surface water types of “rivers” a...
Article
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The polyphasic approach is the most progressive system that has been suggested for distinguishing and phylogenetically classifying Cyanoprokaryota (Cyanobacteria/Cyanophyta). Several oscillatorialean genera (Lyngbya, Phormidium, Plectonema, and Leptolyngbya) have problematic phylogenetic position and taxonomic state because of their heterogeneity a...
Article
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The current study presents data about the diversity and ecology of filamentous blue-green algae, found in the phytoplankton of 42 standing water basins in Bulgaria. We identified 9 species from Cyanoprokaryota, which belong to 5 genera from order Nostocales. Ecological characterization of the identified species has been performed. Data about the ph...
Article
Full-text available
A study of the influence of different extracts from Mentha aquatica L. and Mentha longifolia L. on the activity of glycosyltransferase complex from Leuconstoc nesenteroides URE 13 and dextransucrase from Leuconostoc mesenteroides Lm 28 was carried out. The extracts from two plant species showed an inhibitory effect on studied glycosyltransferases a...
Article
Full-text available
Cyanobacteria are prokaryotic organisms characterized by their ability to produce secondary metabolites with different biological activities. The aim of this work was to evaluate the in vitro and in vivo toxicity of the cosmopolitan freshwater cyanobacterium H. kuetzingii. An extract from H. kuetzingii and cyanobacterial growth media were assessed...
Article
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The ‘normative definitions’ of ecological water quality classes given by the Water Framework Directive (WFD) are narrative descriptions of the conditions present in water bodies of different qualities relative to reference conditions found in unimpacted sites. Defining the type-specific reference conditions for water bodies and finding biological m...
Article
Full-text available
Phytochemical screening of the content of total polyphenols, flavonoids, phenolic acids and anthocyanins in Bulgarian Carduus L. species was carried out. The plant materials (inflorescences) from all of the 14 species found in Bulgaria has been collected from natural habitats from different floristic regions, during the period 2011-2013. Chemical a...
Article
Full-text available
Traditionally, the taxonomy of the genus Nostoc is based on morphological and physiological characters. The extreme morphological variability of the Nostoc species, due to their life cycle and environmental conditions, hampers the correct identification of the individual species. This is also one of the reasons for the disputed taxonomic positions...
Article
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This study presents data on the dominant species Cyanoprokaryota and results from performed toxicological analysis of the water regarding presence of cyanotoxins in three relatively small reservoirs located in Pleven district (Northern Bulgaria): Krushovitsa reservoir, Valchovets reservoir and Enitsa reservoir. Cyanoprokaryotic species Planktothrix...
Article
Full-text available
Treatment of leaf disks with solvents of six neo-clerodane diterpenes isolated from Scutellaria alpina and Salvia splendens and of fi ve their synthetic derivatives, resalted in a signifi cant antifeedant activity against Leptinotarsa decemlineata larvae in choice and no-choice asseys. Relationship structure-activity and changes in the antifeedant...
Article
Full-text available
Traditionally, the taxonomy of the genus Nostoc is based on morphological and physiological characters. The extreme morphological variability of the Nostoc species, due to their life cycle and environmental conditions, hampers the correct identification of the individual species. This is also one of the reasons for the disputed taxonomic positions...
Article
Full-text available
Cyanobacteria are among the oldest autotrophic organisms with cosmopolitan distribution and known as producers of secondary metabolites with toxic properties named “cyanotoxins”. Studies with respect to toxin production of genus Nostoc are yet limited. In the present study we have investigated two Nostoc species (Nostoc linckia and Nostoc punctifor...
Article
Full-text available
The subject of the research was to determine the taxonomic composition , species richness and abundance of the summer phytoplankton in the Stouden Kladenets Reservo ir (the eastern Rhodope Mountains, Bulgaria). A total of 30 taxa were found, belonging to 6 Divisions: Cyanoprokaryota – 3, Chlorophyta – 14, Zygnemaphyta – 3, Chrysophyta – 1, Euglenop...
Article
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The phytoplankton diversity, algal biomass, and selected physicochemical parameters were investigated in the drinking water reservoir (Borovitsa) located in the Kardzhali region, Bulgaria. Particular attention was given to Cyanoprokaryota and presence of cyanotoxins in the water samples. Twenty-nine species belonging to six divisions (Cyanoprokaryo...
Article
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The species structure and quantitative development of the summer phytoplankton in Kurdzhali Reservoir have been studied. A total of 55 species was found, belonging to 6 divisions: Cyanoprokaryota – 13, Chlorophyta – 23, Zygnemaphyta – 5, Dinophyta – 2, Euglenophyta – 3, and Bacillariophyta – 9 species. The divisions Chlorophyta (41.8 %), Cyanoproka...
Article
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Karyotype structures of Scenedesmus acuminatus (Lagerch.) Chod. and Scenedesmus pectinatus Meyen are compared. The karyotype of S. acuminatus (n = 5) is described for the first time. It reveals four large metacentric and one large submetacentric chromosomes (4M + 1SM). The established karyotype differences have been helpful in clarifying the taxono...
Article
Among the Cyanoprokaryota (blue-green algae), the genus Phormidium has thus far rarely been studied with respect to toxin production and potentially resulting human and environmental health effects. We here show that five previously unexplored freshwater species of this genus (Ph. bijugatum, Ph. molle, Ph. papyraceum, Ph. uncinatum, Ph. autumnale)...