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Macroalgae are a natural oceanic resource of inexhaustible abundance for the biomass energy industry with growth rates that are three to four times greater than those of terrestrial plants. The objective of this study was to evaluate the sustainability of macroalgae as biomass for biorefining through two investigations. Firstly, the deposition of macroalgae was sampled through 28 collections on seven beaches in the city of Maceió, Brazil, over a two-year period using a zigzag sampling method, covering a deposition area of 135,000 m2. From this, it was estimated that daily collection would yield 5.03 t/ha of dry biomass. Secondly, the calorific values of macroalgal biomass energy and pellet compounds were calculated. The lower calorific value (8.82 MJ/kg) found from a compound of 13 species analyzed was similar to that of the main biomass used in Brazil to obtain energy, i.e., sugarcane bagasse, which has been evaluated as 8.91 MJ/kg. Macroalgal biomass in the form of condensed energy pellets was found to have a higher calorific value of 20.18 MJ/kg, i.e., 1.2% greater than the average for terrestrial biomass pellets. Based on the results obtained, it was observed that macroalgal biomass has the possibility of becoming a new renewable feedstock with potential for bioenergy. The estimates for the deposition of biomass show possibilities for producing biofuels from marine algal raw material, which provides scope for creating another sustainable alternative for global energy issues with a reduction in environmental problems. [ABSTRACT FROM AUTHOR]

The cytotoxicity of a series of aminonaphthoquinones resulting from the reaction of suitable aminoacids with 1,4-naphthoquinone was assayed against SF-295 (glioblastoma), MDAMB-435 (breast), HCT-8 (colon), HCT-116 (colon), HL-60 (leukemia), OVCAR-8 (ovarian), NCI-H358M (bronchoalveolar lung carcinoma) and PC3-M (prostate) cancer cells and also against PBMC (peripheral blood mononuclear cells). The results demonstrated that all the synthetic aminonaphthoquinones had relevant cytotoxic activity against all human cancer lines used in this experiment. Five of the compounds showed high cytotoxicity and selectivity against all cancer cell lines tested (IC50 = 0.49 to 3.89 μg·mL-1). The title compounds were less toxic to PBMC, since IC50 was 1.5 to eighteen times higher (IC50 = 5.51 to 17.61 μg·mL-1) than values shown by tumour cell lines. The mechanism of cell growth inhibition and structure-activity relationships remains as a target for future investigations. [ABSTRACT FROM AUTHOR]

This work reports the development of a dispersive liquid -liquid microextraction method for the simultaneous extraction, preconcentration, and derivatization of Hg2+ and CH3 Hg+ species from water samples for further determination by GC - MS. Some parameters of the proposed method, such as volume and type of disperser and extraction solvent, and Na[ B( C6 H5)4] concentration were investigated using response surface methodology. Suitable recoveries were obtained using 80 μL C2 Cl4 (as extraction solvent), 1000 μL ethanol (as disperser solvent), and 300 μL 2.1 mmol/L Na[ B( C6 H5)4] (as derivatizing agent). Accuracy was evaluated in terms of recovery and ranged from 87 to 99% with RSD values <7%. In addition, a certified reference material of water ( NIST 1641d) was analyzed and agreed with the certified value about 107% (for Hg2+), with RSD values <8.5%. LODs were 0.3 and 0.2 μg/L, with enrichment factors of 112 and 115 for Hg2+ and CH3 Hg+, respectively. The optimized method was applied for the determination of Hg2+ and CH3 Hg+ in tap, well, and lake water samples. [ABSTRACT FROM AUTHOR]

This paper reports, for the first time, the development of an analytical method employing modified matrix solid-phase dispersion (MSPD) for the extraction of CH3Hg+ and Hg2+ species from fish samples. Separation and determination of mercury species were performed by gas chromatography coupled to mass spectrometry (GC/MS). Important MSPD parameters, such as sample mass, type and mass of solid support, concentration of extraction solution (HCl and NaCl), and stirring time, were investigated by the response surface methodology. The derivatization step and the separation of mercury species were also evaluated for the determination by GC/MS. Quantitative recoveries were obtained with 0.2 g of fish sample, 0.5 g of SiO2 as the solid support, 0.5 mol L-1 NaCl and 4.2 mol L-1 HCl as the extraction solution, and 1 min stirring time. The MSPD method showed to be suitable for the extraction and determination of mercury species in certified reference materials of dogfish liver (DOLT-3) and dogfish muscle (DORM-2). It had good agreement (about 99%) with the certified values, and the relative standard deviation was lower than 9.5%. The limits of detection were 0.06 and 0.12 μg g-1, for CH3Hg+ and Hg2+, respectively. A matrix effect was observed, and the quantification was carried out by the matrix-matched calibration. The method was applied to tuna fish (Thunnus thynnus), angel shark (Squatina squatina), and guitarfish (Rhinobatos percellens) samples. The results of the mercury speciation by MPSD and GC/MS were compared to the total mercury concentration determined by flow injection cold vapor generation inductively coupled plasma mass spectrometry, after microwave-assisted digestion. Agreement ranged from 102% to 105%. [ABSTRACT FROM AUTHOR]

This work reports the development of a dispersive liquid-liquid microextraction method for the simultaneous extraction, preconcentration, and derivatization of Hg(2+) and CH3Hg(+) species from water samples for further determination by GC-MS. Some parameters of the proposed method, such as volume and type of disperser and extraction solvent, and Na[B(C6H5)4] concentration were investigated using response surface methodology. Suitable recoveries were obtained using 80 μL C2 Cl4 (as extraction solvent), 1000 μL ethanol (as disperser solvent), and 300 μL 2.1 mmol/L Na[B(C6H5)4] (as derivatizing agent). Accuracy was evaluated in terms of recovery and ranged from 87 to 99% with RSD values <7%. In addition, a certified reference material of water (NIST 1641d) was analyzed and agreed with the certified value about 107% (for Hg(2+)), with RSD values <8.5%. LODs were 0.3 and 0.2 μg/L, with enrichment factors of 112 and 115 for Hg(2+) and CH3Hg(+), respectively. The optimized method was applied for the determination of Hg(2+) and CH3Hg(+) in tap, well, and lake water samples., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Xylopia laevigata, popularly known as "meiú" and "pindaíba", is a medicinal plant used in the folk medicine of the Brazilian Northeast for several purposes. The chemical constituents of the essential oil from leaves of X. laevigata, collected from wild plants growing at three different sites of the remaining Atlantic forest in Sergipe State (Brazilian Northeast), were analyzed by GC/FID and GC/MS. The effect of the essential oil samples was assessed on tumor cells in culture, as well on tumor growth in vivo. All samples of the essential oil were dominated by sesquiterpene constituents. A total of 44 compounds were identified and quantified. Although some small differences were observed in the chemical composition, the presence of γ-muurolene (0.60-17.99%), δ-cadinene (1.15-13.45%), germacrene B (3.22-7.31%), α-copaene (3.33-5.98%), germacrene D (9.09-60.44%), bicyclogermacrene (7.00-14.63%), and (E)-caryophyllene (5.43-7.98%) were verified as major constituents in all samples of the essential oil. In the in vitro cytotoxic study, the essential oil displayed cytotoxicity to all tumor cell lines tested, with the different samples displaying a similar profile; however, they were not hemolytic or genotoxic. In the in vivo antitumor study, tumor growth inhibition rates were 37.3-42.5%. The treatment with the essential oil did not significantly affect body weight, macroscopy of the organs, or blood leukocyte counts. In conclusion, the essential oil from the leaves of X. laevigata is chemically characterized by the presence of γ-muurolene, δ-cadinene, germacrene B, α-copaene, germacrene D, bicyclogermacrene, and (E)-caryophyllene as major constituents and possesses significant in vitro and in vivo anticancer potential., (Georg Thieme Verlag KG Stuttgart · New York.)

Background: Animal venoms are complex mixtures of proteins and non proteins components with several biological activities. Snake venoms represent an essentially unexplored source of bioactive compounds that may cure disease conditions which do not respond to currently available therapies. These venoms possess many pharmacological activities, as cytotoxic and/or lytic effects on tumor cells in vitro. Herein, were investigated the in vitro cytotoxicity of three Bothrops venoms in tumor cell lines., Methods: Cytotoxic effect was evaluated in HCT-8 (colon - human), SF-295 (nervous system - human), HL-60 (human leukemia) and MDAMB-435 (breast - human). Cell density and membrane integrity were determined by the exclusion of propidium iodide. To determine whether Bothrops venoms treated cells were undergoing an apoptotic and/ or necrosis death, phosphatidylserine (PS) externalization was measured after the incubation with the venom., Results: Botrhops venons showed significant cytotoxcity against all cell lines in study. Cell density and membrane integrity were determined by the exclusion of propidium iodide. The Bothrops venoms reduced the cell number and revealed the presence of a necrotic population when the cells was exposed to the B. pauloensis B. diporus and B. pirajai venoms. To determine whether Bothrops venoms treated cells were undergoing an apoptotic and/or necrosis death, PS externalization was measured after the incubation with the venom and it was observed necrotic and apoptotic cells., Conclusions: All Bothrops venoms tested showed cytotoxicity against tumor cell lines through inducing of necrosis and apoptosis.