The present paper is aimed at describing a “closed cycle” power plant schematic (SOFT, Solar Oxygen Fuel Turbine) with macroalgae (seaweed) cultivation in a pond, combustion of its organic matter in a fluidized bed boiler of Rankine cycle and return of the combustion products to the pond to feed algae. The oxygen used for combustion is released to atmosphere in photosynthesis. As a renewable fuel for combustion after drying the seaweed Ulva lactuca is selected. Its growth rate from many experiments (in literature) is 0.1 – 0.2 1/day, heating value of dry weight is 19 MJ/kg, optimal concentration in salty water 1: 1000. Energy efficiency is less than in photovoltaics but energy expenditures to construct the pond as solar energy receiver are much less, it gives some economic benefits. The present paper highlights the interest of immediate combustion of the dried biomass fuel without converting it in liquid transportation fuel. The latter is the cause of additional technological problems and energy losses.

The antioxidant activities ofUlva faciata, Nizimuddinia zanardinii and Gracilaria corticatawere investigated in Chabahar, Iran. Methanol extract and n-hexane, dichloromethane and ethylacetate fractions used for antioxidative properties test by the total antioxidative activity, 2, 2-diphenyl-1-picryl-hydrazylhydrate (DPPH) free radical scavenging activity, reduction power, metal chelating activity and inhibition of lipid peroxidation methods. The methanolic extracts of three seaweed species showed lower antioxidative properties. The most effective antioxidant properties were observed from the EA fractions ofG. corticata and U. faciata. dichloromethane (DCM), fraction of N.zanardiniishowed significantly higher total antioxidative activity, DPPH radical scavenging and power reduction in comparison to its n-hexane, EA fractions and crude MeOH extract. There was a strong correlation between the reduction power (r2=0.94) and the total phenolic content of the seaweeds extracts and fractions. The results indicateU. faciata and G. corticata can be potential sources of natural antioxidants and may be efficiently used as nutraceuticals.

Background and purpose: In some countries, seaweeds are famous traditional food which contain different types of secondary metabolites. These marine organisms have several bioactive secondary metabolites. The aim of this study was to perform bioassay-guided isolation of glycolipids from a Persian Gulf seaweed Gracilaria corticata J. Agardh. Experimental approach: G. corticata was collected from the Persian Gulf. The plant was extracted by maceration with methanol-ethyl acetate solvent. The extract was partitioned by the Kupchan method to yield n-hexane, dichloromethane, butanol, and water partitions. The most active partition found in the cytotoxicity assay was further fractionated using medium pressure liquid chromatography and high-performance liquid chromatography (HPLC) methods to yield two pure compounds. The structures of the isolated compounds were elucidated using various spectroscopic methods. The cytotoxic activities of all fractions were also tested. Findings/Results: n-hexane and dichloromethane partitions exhibited higher and significant cytotoxicity against the HeLa cell line with IC50s of 117. 41 and 291. 38 µ g/mL, respectively. The cytotoxic effects of nine fractions of the n-hexane partition against HeLa and HUVEC cells were also ranging from 96. 33 to 243. 56 µ g/mL and 85. 38 to 290. 5 µ g/mL, respectively. Two sulfoquinovosyldiacylglycerides were isolated and their structures were elucidated. Conclusion and implications: From the spectral characteristics, the isolated compound from the extract was confirmed to be α-D-glucopyranosyl-1, 2-O-diacyl-glycerols with moderate cytotoxic activity.