Antonina Vitkova

Beech forest communities in Bulgaria

Beech forests occupy considerable areas in the Bulgarian mountains. They are represented by communities of Fagus sylvatica (incl. F. moesiaca) and F. orientalis, and also by mixed stands of beech with Abies alba, Carpinus betulus, Quercus cerris, Q. dalechampii and Q. polycarpa. 494 releves sampled across the country were analysed by numerical methods. They were classified into 12 groups of Fagus sylvatica forests and 3 groups of Fagus orientalis forests. The analysis of Bulgarian Fagus sylvatica communities did not show a distinct pattern of geographic differentiation and did not support the concept of the alliance Fagion moesiacum, as accepted by many earlier authors. The differentiation patterns in the Bulgarian Fagus sylvatica forests mainly follow the gradients in soils and climate, and are similar to those in the Central European beech forests. Therefore we accept a syntaxonomical scheme, which emphasizes variation due to edaphic and local topoclimatic factors rather than due to large-scale geographical differentiation. This scheme is very close to that proposed by Willner (2002) for the southern Central European beech forests, and includes the alliances Luzulo-Fagion (acidophilous beech forests), Asperulo-Fagion (nutrient-rich beech forests), and Cephalanthero-Fagion (thermophilous beech forests). The communities of Fagus orientalis are markedly different from the communities of Fagus sylvatica, have a distinct floristic composition, and belong to the Euxinian alliance Fagion orientalis.

Terpenoids from Anthemis austriaca Jacq.

The aerial parts of Anthemis austriaca Jacq. afforded five new sesquiterpene lactones (two of which are dimeric guaianolides) and three new guaiane type sesquiterpene acids. In addition, seven known terpenoids were also found in the studied species. Their structures were elucidated by spectral methods.

Developmental and Environmental Effects on Sesquiterpene Lactones in Cultivated Arnica montana L.

The amount of sesquiterpene lactones and the lactone profile of Arnica montana L. in flowering and seed formation stages in vitro and in vivo propagated from seeds of German, Ukrainian, and Austrian origin and grown in two experimental fields were studied. It was found that in vitro propagated 2‐year plants in full flowering stage accumulated higher amount of lactones in comparison to in vivo propagated 3‐year plants and to the seed formation stage, respectively. Helenalins predominated in in vivo propagated 2‐year or in vitro propagated 3‐year plants. 2‐Methylbutyrate (2MeBu) was the principal ester in the samples with prevalence of helenalins, while isobutyrate (iBu) was the major one in the samples with predominance of 11,13‐dihydrohelenalins. The results revealed that the environmental conditions on Vitosha Mt. are more suitable for cultivation of A. montana giving higher content of lactones.

Embryological features, pollen and seed viability of Arnica montana (Asteraceae) – a threatened endemic species in Europe

Abstract The embryological features, mode of reproduction and reproductive capacity (pollen and seed viability) on two naturalized populations of Arnica montana in Bulgaria were studied. The embryological study shows that A. montana is a facultative apomictic species in which sexual reproduction predominates. In this species, it was established that there is a comparatively high viability of the mature pollen and embryos, which enables the successful realization of its reproductive capacity. The results of the study on A. montana reveal that both sexual and asexual vegetative reproduction with rhizomes undoubtedly play more important roles than the apomixis (namely diplospory) for support and preservation of the populations.

Composition of the Essential Oil of Achillea Asplenifolia Vent. from Bulgaria

Abstract The essential oil composition of Achillea asplenifolia Vent. flower heads of Bulgarian origin is analysed by GC and GC-MS. The main constituents of the oil were chamazulene (25.6%), β-pinene (21.4%), sabinene (15.9%), and β-caryophyllene (11.3%). Antimicrobial activity tests against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Proteus vulgaris and Candida albicans revealed significant bacteriacidal and fungicidal effects against S. aureus, C. albicans respectively and weaker against E. coli.

Chemotypes of Artemisia Ierchiana Weber. from Bulgaria

Abstract The chemical composition of essential oils of 16 samples of Artemisia lerchiana Weber., collected in northeast Bulgaria has been analyzed by GC and GC/MS. The main components were found to be 1,8-cineole (1.8–45.5%), α-thujone (2.5–47.8%), β-thujone (0.0–34.5%), camphor (0.0–45.7%), borneol (0.0–16.0%), cis-sabinol (0.025.6%), davanone (0.0–38.3%) and β-cubebene (2.6–20.8%). The results revealed the existence of chemotypes within the investigated samples.

Chemometrics-based approach in analysis of Arnicae flos

Introduction: Arnica montana flowers have a long history as herbal medicines for external use on injuries and rheumatic complaints. Objective: To investigate Arnicae flos of cultivated accessions from Bulgaria, Poland, Germany, Finland, and Pharmacy store for phenolic derivatives and sesquiterpene lactones (STLs). Materials and Methods: Samples of Arnica from nine origins were prepared by ultrasound-assisted extraction with 80% methanol for phenolic compounds analysis. Subsequent reverse-phase high-performance liquid chromatography (HPLC) separation of the analytes was performed using gradient elution and ultraviolet detection at 280 and 310 nm (phenolic acids), and 360 nm (flavonoids). Total STLs were determined in chloroform extracts by solid-phase extraction-HPLC at 225 nm. The HPLC generated chromatographic data were analyzed using principal component analysis (PCA) and hierarchical clustering (HC). Results: The highest total amount of phenolic acids was found in the sample from Botanical Garden at Joensuu University, Finland (2.36 mg/g dw). Astragalin, isoquercitrin, and isorhamnetin 3-glucoside were the main flavonol glycosides being present up to 3.37 mg/g (astragalin). Three well-defined clusters were distinguished by PCA and HC. Cluster C1 comprised of the German and Finnish accessions characterized by the highest content of flavonols. Cluster C2 included the Bulgarian and Polish samples presenting a low content of flavonoids. Cluster C3 consisted only of one sample from a pharmacy store. Conclusion: A validated HPLC method for simultaneous determination of phenolic acids, flavonoid glycosides, and aglycones in A. montana flowers was developed. The PCA loading plot showed that quercetin, kaempferol, and isorhamnetin can be used to distinguish different Arnica accessions. SUMMARY A principal component analysis (PCA) on 13 phenolic compounds and total amount of sesquiterpene lactones in Arnicae flos collection tended to cluster the studied 9 accessions into three main groups. The profiles obtained demonstrated that the samples from Germany and Finland are characterized by greater amounts of phenolic derivatives than the Bulgarian and Polish ones. The PCA loading plot showed that quercetin, kaemferol and isorhamnetin can be used to distinguish different arnica accessions.

Distribution and Ecology of Alchemilla Species in Osogovo Mt. and West Balkan Mt. In Bulgaria

Distribution and Ecology of Alchemilla Species in Osogovo Mt. and West Balkan Mt. In Bulgaria The present study aims to determine some common species of genus Alchemilla (Rosaceae) in Osogovo Mt. and West Balkan Mt. in Bulgaria. The ecological conditions in seven habitat types according to EUNIS with detected presence of Alchemilla species are compared. According to this classification, the habitats that were found belong to six general types: Transition mires and quaking bogs (D 2.3), Mountain hay meadows (E 2.3), Moist or wet eutrophic and mesotrophic grassland (E 3.4), Acid alpine and subalpine grassland (E 4.3), Subalpine moist or wet tall-herb and fern stands (E 5.5), Evergreen alpine and subalpine heath and scrub (F 2.2). Seven species were reported in the investigated regions: A. crinita Buser, A. erythropoda Juz., A. flabellata Buser, A. glabra Neygenf., A. glaucescens Wallr., A. monticola Opiz and A. viridiflora Rothm. In the paper are submitted some new reports for the presence of A. crinita, A. erythropoda and A. glabra in the investigated areas. Some preliminary results concerning the resources of the examined species are obtained. V raziskavi smo predstavili nekaj vrst rodu Alchemilla (Rosaceae) na gorovjih Osogovo in Zahodni Balkan (Stara Planina) v Bolgariji. Primerjali smo rastiščne razmere v sedmih habitatnih tipih po razvrstitvi EUNIS, v katerih smo ugotovili prisotnost vrst Alchemilla. Po tej razvrstitvi najdene habitate uvrščamo v šest glavnih tipov: prehodna barja (D 2.3), gorski gojeni travniki (E 2.3), mokrotni mezotrofni in eutrofni travniki ali pašniki (E 3.4), alpinska in subalpinska travišča na kisli podlagi (E 4.3), subalpinska in alpinska visoka steblikovja (E 5.5), arktično-alpinske in borealne resave (F 2.2). V raziskovanem območju smo našli sedem vrst: A. crinita Buser, A. erythropoda Juz., A. flabellata Buser, A. glabra Neygenf., A. glaucescens Wallr., A. monticola Opiz and A. viridiflora Rothm. V članku so prikazana nova nahajališča vrst A. crinita, A. erythropoda in A. glabra na raziskovanem območju. Prikazali smo tudi predhodne rezultate koristne uporabe proučevanih vrst rodu Alchemilla.

Lignans and Alkaloids from Haplophyllum suaveolens

Summary. A new lignan of the dibenzylbutyrolactone type, haplotonin, was isolated from the aerial parts of Haplophyllum suaveolens together with five known compounds-the alkaloids flindersine, 6-methoxyflindersine, N-acetoxymethylflindersine, and evoxine and the lignan 4-acetyldiphyllin. This is the first report on the occurrence of N-acetoxymethylflindersine in the genus Haplophyllum and on 6-methoxyflindersine and 4-acetyldiphyllin as constituents of the investigated species.