Zornitsa Kamenarska

Antibacterial, antiviral, and cytotoxic activities of some red and brown seaweeds from the Black Sea.

Abstract Chloroform extracts, n- butanol extracts, water extracts,and volatile compounds from seven species belongingtosix Black Sea genera of brown algae and 10 speciesbelonging to seven Black Sea genera of red algae wereassessed for antibacterial, antiviral, and cytotoxic prop-erties. Most of the extracts showed pronounced effectsagainst the Gram (q) bacterium Staphylococcus aureus .Activity towards the Gram (-) bacterium Escherichia coli was found in only few cases. A significant reduction inreplication of influenza and Herpes simplex viruses in cellcultures was observed. Cytotoxic effect was establishedin a significant proportion of the algae investigated. Thebiological activities may be attributed to the presence ofvolatile compounds, some phenols, free fatty acids andtheir oxidized derivatives, eucalyptol, the methyl ester ofphenyl acetic acid, and 1,2-dihydroxy ethane sulfonate. Keywords: biological activities; extracts; red and brownBlack Sea algae. Introduction Marine algae have been evaluated as an attractivesourceof potential drug compounds in several biochemical andpharmacological investigations (Kerr and Kerr 1999,Luescher-Mattli 2003, Simmons et al. 2005, Lahaye andRobic 2007). Being in permanent contact with pollutants(and in order to survive in such unfriendly environments),different marine organisms, such as fungi, viruses, bac-teria, etc., synthesize or accumulate defensive com-pounds. Diverse algal extracts have been investigatedfortheir antimicrobial, cytotoxic, antitumor, antiviral, andanti-inflammatory properties (Konig and Wright 1996,Mandal et al. 2007). Our preliminary investigationsshowed that some widespread Black Sea algae possessantimicrobial, antiviral, antifungal and cytotoxic activities(Stefanov et al. 1998, Kujumdjiev et al. 1999, Serkedjieva2000, Kamenarska et al. 2002). Evidently, most of thebiologically active compounds found in marine algaehave defensive functions. A proportion of these com-pounds are secreted into surrounding seawater.In the present study, we continued the investigation ofantibacterial, cytotoxic, and antiviral activities of themostwidely distributed macroalgae in the Bulgarian part of theBlack Sea, which has not been studied until now. More-over, the results obtained were compared with the chem-ical compositions of the corresponding extracts.

Volatile compounds from some Black Sea red algae and their chemotaxonomic application

Abstract Volatile compounds from the Black Sea red algae Bangia fuscopurpurea, Gelidium latifolium, Callithamnion granulatum, Ceramium elegans, Laurencia papillosa and Laurencia coronopus were obtained by distillation-extraction and analysed by GC/MS. Different groups of compounds were identified: hydrocarbons, alkylated benzenes, alcohols, phenols, aldehydes, ketones, acids, esters, terpenes, nitrogen- and halogen-containing compounds. The results are compared with some recent data for the composition of the volatile compounds from four previously investigated Black Sea red algae, which are at different evolutionary stages. On the basis of their qualitative and semi-quantitative composition some chemotaxonomic conclusions are proposed. The eventual functions of some of the volatile compounds are briefly discussed.

Chemical composition and biological activity of the brackish-water green alga Cladophora rivularis (L.) Hoek

Abstract The chemical composition of the brackish-water green alga Cladophora rivularis was investigated. Seven sterols were identified and the stereochemistry of the most common forms was established. Thirty-eight and 21 compounds were identified in the volatile and polar fractions, respectively. The main lipid classes were isolated and their fatty acid compositions established. The antibacterial, antimycotic and cytotoxic activities of the extracts were investigated. Comparisons were made with previously investigated marine and freshwater Cladophora species. Results obtained give information on the effect of salinity on algal metabolism.

Chemical composition of Cystoseira crinita Bory from the Eastern Mediterranean.

The chemical composition of the brown alga Cystoseira crinita Bory from the Eastern Mediterranean was investigated. Fourteen sterols have been identified, five of them for the first time in algae. The structure of one new sterol was established. The origin of seven sterols with short side chains was discussed. In the volatile fraction 19 compounds and in the polar fraction 15 compounds were identified. The main lipid classes were isolated and their fatty acid composition was established.

Comparative Study of the Volatile Compounds from Some Black Sea Brown Algae

Abstract Volatile compounds from seven species of brown algae, wide-spread in the Black Sea, were obtained by distillation-extraction and investigated by GC/MS. Different groups of compounds were identified: hydrocarbons, alkylated benzenes, alcohols, phenols, aldehydes, ketones, acids, esters, terpenes, sulfur- and chlorine-containing compounds. On the basis of their qualitative and semi-quantitative composition some conclusions about the taxonomy and evolution of the species investigated are proposed. The functions of some of the volatile compounds are discussed.

Comparative investigation on sterols from some Black Sea red algae

The sterol composition of five Black Sea red algae: Callithamnion granulatum, Ceramium rubrum, Ceramium elegans, Laurencia papillosa and Laurencia coronopus was obtained. Monohydroxy sterols and their oxidized derivatives have been identified. The results obtained were compared with some recent data for the composition of sterols in other Black Sea red algae, which occupy different evolutionary positions. On the basis of their composition, some conclusions about the chemotaxonomy and chemoevolution of the species investigated have been proposed.

Chemical Composition and Biological Activities of the Black Sea Algae Polysiphonia denudata (Dillw.) Kutz. and Polysiphonia denudata f. fragilis (Sperk) Woronich

Abstract The two investigated algae had almost identical sterol composition, but there were significant differences in the com position of the polar components and especially in the composition of the volatiles. P. denudata f. fragilis extracts possessed a stronger biological activity (antibacterial, antifungal and toxicity against Artemia salina). Despite the minute morphological differences between the two algae, we recommend P. denudata f. fragilis to be regarded as P. denudata subsp. fragilis.

Lipophylic compounds from Euphorbia peplis L.--a halophytic plant from the Bulgarian Black Sea coast.

Abstract The chemical composition of the lipophylic fraction from the halophytic plant Euphorbia peplis L. was investigated. Compared to other terrestrial higher plants an increase of triacylglycerols and especially of glycolipids was observed. The main phospholipid was phosphatidyl choline, followed by almost equal concentrations of phosphatidyl ethanolamine and phosphatidyl glycerol. A relatively high concentration of phosphatidic acids (6.5% of the total phospholipids) was found. The main sterol appeared to be sitosterol and significant amounts of tetracyclic triterpene alcohols were found. The composition of the volatile compounds is relatively simple and only one chlorinated compound, identified as 2,2-diethoxy-1-chloroethane, was found. There was a strong toxicity of the total lipophylic extract towards Artemia salina.

Chemical Composition of Corallina mediterranea Areschoug and Corallina granifera Ell. et Soland

Abstract The composition of sterols, volatiles and some polar compounds from three Corallina samples (C. granifera and C. mediterranea from the Black Sea and C. mediterranea from the Mediterranean Sea) was established. The sterol composition of the Black Sea samples was similar but it differs from that of the Mediterranean sample. The composition of the volatiles was very complex. The main groups of constituent were hydrocarbons, alcohols, carbonyl compounds, acids and their esters, terpenes. The composition of the polar components, soluble in n-butanol, was also established. There were some differences in the chemical composition of the two Black Sea species, which may be due to the biodiversity between them, while the differences in the composition of the two C. mediterranea samples could be due to the differences in the environment (salinity, temperature, pollution, etc.).

Sterol and lipid composition of three Adriatic Sea sponges.

Abstract The sterol and fatty acid composition of three Adriatic Sea sponges (Geodia cydonium and two unidentified Tedania sp.), collected at the same time and same place, was established. Twenty-four sterols and forty fatty acids were identified. The identical ecological conditions, including the diet, allowed us to apply the results obtained for taxonomical conclusions, based on the biodiversity of the investigated sponges. On the basis of the sterol composition they can be separated into two groups: Tedania and Geodia sponges. The sterol and fatty acid composition indicates that the two investigated Tedania samples might be different species or subspecies