Kasim Cemal Güven

Alkaloids in Marine Algae

This paper presents the alkaloids found in green, brown and red marine algae. Algal chemistry has interested many researchers in order to develop new drugs, as algae include compounds with functional groups which are characteristic from this particular source. Among these compounds, alkaloids present special interest because of their pharmacological activities. Alkaloid chemistry has been widely studied in terrestrial plants, but the number of studies in algae is insignificant. In this review, a detailed account of macro algae alkaloids with their structure and pharmacological activities is presented. The alkaloids found in marine algae may be divided into three groups: 1. Phenylethylamine alkaloids, 2. Indole and halogenated indole alkaloids, 3. Other alkaloids.

Heavy metal monitoring of marine algae from the Turkish Coast of the Black Sea, 1998-2000

Concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in macroalgae samples collected from the Turkish Coast of the Black Sea. Certain algae species were chosen among the green, brown and red algae species at Sile and Sinop sampling stations from 1998 to 2000. In general, as regards the influence of the collection sites on the whole metal accumulation, Sinop is considered to be more polluted than Sile. The concentrations of the heavy metals in Cystoseira barbata algae are compared with previous studies in the same stations. The results showed that all metal levels have gradually decreased during past years. At the same time, Cd, Co, Cr, Cu, Fe, Ni and Pb levels in the present study are lower than in Bosphorus and Marmara Sea algae. However, Mn and Zn concentrations are higher than Bosphorus but lower than at Marmara. According to these findings the heavy metal pollution decreased in Turkish Coast of the Black Sea during the years investigated.

Survey of Metal Contents of Bosphorus Algae, Zostera marina and Sediments

This paper reports on heavy metal pollution in five algae, a phanerogam and the sediments collected from seven stations in the Bosphorus. The phanerogam Zostera marina showed higher metal levels than the algae tested. The metal contents were always higher in sediments than in the algae and Zostera marina

Metal uptake by Black Sea algae

This paper reports a study on the metal content of Black Sea algae from 1979 to 1988. Pollution was found to increase during this time. The metals accumulated in different algal taxa were: in green algae, Al, Cr and Fe; in brown algae, As and Sr; in red algae, Ag, Cd, Co, Cu, Hg, Mn, Pb, Se and Zn. The role of the valence number of the metals accumulated in the algae could not be related to their systematic position

Trace Metals in Marine Algae and Sediment Samples from the Bosphorus

Concentration of As, Cr, Fe, Zn, Co, Sb, Pb, Cd and Cu weredetermined in sediment and algae samples collected from theBosphorus in Turkey. Certain algae species were chosen among thegreen, brown and red algae species at three sampling stations.Element analyses were carried out by atomic absorptionspectrophotometry and instrumental neutron activation analysis. The locations having the highest metal concentrations insediments were as follows: As at Poyraz; Cr, Zn, Sb at RumeliFeneri and Fe, Co at Garipçe. In genral, the accumulation ofmost of the metals showed no direct correlation with algaespecies. On the other hand, C. verticillatus and C. barbataspecies of brown algae showed ability to accumulate arsenic.

Comparison of fatty acid contents of wild and cultured rainbow trout Onchorhynchus mykiss in Turkey

The total lipid content and fatty acid composition were determined in the flesh and skin of wild and cultured rainbow trout in Turkey. The effect of diet content was also investigated on cultured trout. Gas chromatography-mass spectrometry (GC-MS) was used for fatty acid analyses. Total lipid content of skin was higher than flesh in both types and when compared appreciably higher in cultured fish. The predominant fatty acid was palmitic acid (C16∶0) in saturated fatty acids and oleic acid (C18∶1n−9) in monounsaturated fatty acids. The amount of eicosapentaenoic acid was double in wild and docosahexaenoic acid (DHA) 1.5 times higher in cultured fish flesh. The n−3/n−6 ratio was higher in cultured fish than wild fish. The levels of palmitic, oleic, linoleic (C18∶2n−6) and palmitoleic (C16∶1n−7) acids were high in skin. The level of EPA was the same in skin of wild fish but 5.5 times higher in cultured fish, where as the proportion of DHA in skin was lower for wild and 3.5 times higher in cultured fish. Wild fish had a high level of linoleic, arachidonic (C20∶4n−6) and linolenic (C18∶3n−3) acids. The total amount of n−3 and n−6 polyunsaturated fatty acids was higher in flesh of wild fish than cultured fish, contrary to skin of cultured fish. The data obtained demonstrated that fatty acid composition of cultured fish did not depend on that of feed.

Heavy metal accumulation in algae and sediments of the Black Sea coast of Turkey

The paper reports heavy metal accumulation in algae collected at four stations and in sediments at three stations on the Black Sea coast of Turkey. The metals analysed are Cd, Co, Cr, Cu, Fe, Pb, Sb and Zn. The metal content of algae increased generally (with some exceptions) from 1991 till 1993 in Şile and Sinop. In the sediments Sb in Şile, As in Riva, Fe, Zn in Sinop are high. According to these findings the metal pollution increased in Turkish area of the Black Sea during the years investigated.

Loliolide in marine algae.

Loliolide content was determined in 13 marine algae including red, brown and green algae collected from the Black Sea, the Dardanelles and the Aegean Sea. Identification and quantification were performed by gas chromatography-mass spectrometry. The loliolide content in green alga is 1.76 µg g−1, ranges from 0.14 to 4.35 µg g−1 in red and from 0.18 to 4.83 µg g−1 in brown algae. The results obtained are in the same range as previously reported for algae, as well as terrestrial plants. This article represents the first report of loliolide occurrence in green algae.

Selectivity of heavy metal binding by algal polysaccharides

The selectivity of heavy metal binding by algal polysaccharides such as alginic acid, carrageenan types and agar was investigated. Lead was retained in highest amounts by alginate. Algal polysaccharides were ranked as: Sodium alginate > carrageenans > agar for metal binding. The functional groups of algal polysaccharides are found to be effective in heavy metal binding selectivity and those containing carboxylic groups retained heavy metals higher than those with sulphate groups.

The influence of chernobyl on the radiocesium contamination in lichens in Turkey

Lichen samples collected before and after the Chernobyl accident were analysed for radiocesium activity. 137Cs activity was detected in some samples collected before Chernobyl. 134Cs and 137Cs were detected in all the samples after the accident. The levels of the total cesium activity counted in the samples proved that the eastern region of the Black Sea was affected by Chernobyl at a very high degree compared with other parts of Turkey.