Algae(and their extracts)are increasingly important for pharmaceutical applications due to the diversity of useful compounds they contain.The genus Fucus contains one of the most studied species,Fucus vesiculosus.The ...Algae(and their extracts)are increasingly important for pharmaceutical applications due to the diversity of useful compounds they contain.The genus Fucus contains one of the most studied species,Fucus vesiculosus.The species F.ceranoides differs from the others of the genus by presenting longitudinal air-vesicles and a capacity to survive at low salinities.It is an alga that inhabits the Mondego River estuary(Portugal),at the southern limit of its distribution,and can serve as a role model to understand the effect of a salt gradient on the production of bioactive compounds.We assessed the phenolic content and antioxidant activity of different F.ceranoides extracts(e.g.methanolic,aqueous and polysaccharide)prepared from samples harvested from two different zones to evaluate if the adaptation of F.ceranoides to different salinity levels influenced its chemical composition.The antioxidant activity of the extracts was determined using 1,2-diphenyl-picrylhydrazyl(DPPH)and 2.2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)radicals.These assays demonstrated that the methanolic extract of lyophilized F.ceranoides that grew at low salinities was the most bioactive,i.e.DPPH(IC 50=50.39μg/mL)and ABTS(TEAC=2.42).The total phenolic content(Folin-Ciocalteu method)and the methanolic extract of the lyophilized F.ceranoides collected from a low salinity habitat exhibited the highest phenolic content(PGE=49.48μg/mg of lyophilized extract)amongst those sampled.Thin layer chromatography(TLC)and Fourier transform infrared spectroscopy(FTIR)were used for the identification of compounds in the extracts.This characterization allowed confirmation that the various extracts contained almost the same compounds but with notable quantitative differences.Based on these results,we conclude that there were differences in the quantity of the compounds due to the effect of salinity.The drying methods used were also found to have influenced the quality of the extracted compounds.展开更多
Spatial distribution and temporal dynamics of phytoplankton community and their relationships with environmentalfactors were studied in the Pearl River Estuary (PRE), South China, in three seasons. Salinity was cons...Spatial distribution and temporal dynamics of phytoplankton community and their relationships with environmentalfactors were studied in the Pearl River Estuary (PRE), South China, in three seasons. Salinity was considered as the key environ-mental variable controlling horizontal distributions of phytoplankton community composition. A transition from dominance offreshwater diatoms (Aulacoseira granulata and A. granulata v. angustissima) to estuarine species (Skeletonema costatum and Pseu-donitzschia delicatissima) was observed in the high flow season (summer) along the estuary gradient; in the low flow season (spring),the inner estuary was relatively homogeneous and some typical estuarine species could be found near the river mouth. In the normalflow season (autumn), a potentially toxic bluegreen species, Microcystis spp. was predominant in the middle reaches of the estuary,which should be seeded from upstream and transported downstream by river discharges. Phytoplankton abundance was negativelycorrelated with suspended solid content and nutrient concentration in the PRE, suggesting that turbidity and nutrient availability werethe crucial factors regulating the algal biomass. Phytoplankton abundance in the outer estuary was enhanced by increasing irradianceand continued to be enhanced until phosphorus-limitation.展开更多
基金Fundacao para a Ciencia e Tecnologia(FCT),through the strategic project UID/MAR/04292/2013 granted to MAREEuropean Structural&Investment Funds through the COMPETE Programme and from National Funds through FCT-Fundacao para a Ciencia e a Tecnologia under the Programme(No.SAICTPAC/0019/2015).
文摘Algae(and their extracts)are increasingly important for pharmaceutical applications due to the diversity of useful compounds they contain.The genus Fucus contains one of the most studied species,Fucus vesiculosus.The species F.ceranoides differs from the others of the genus by presenting longitudinal air-vesicles and a capacity to survive at low salinities.It is an alga that inhabits the Mondego River estuary(Portugal),at the southern limit of its distribution,and can serve as a role model to understand the effect of a salt gradient on the production of bioactive compounds.We assessed the phenolic content and antioxidant activity of different F.ceranoides extracts(e.g.methanolic,aqueous and polysaccharide)prepared from samples harvested from two different zones to evaluate if the adaptation of F.ceranoides to different salinity levels influenced its chemical composition.The antioxidant activity of the extracts was determined using 1,2-diphenyl-picrylhydrazyl(DPPH)and 2.2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)radicals.These assays demonstrated that the methanolic extract of lyophilized F.ceranoides that grew at low salinities was the most bioactive,i.e.DPPH(IC 50=50.39μg/mL)and ABTS(TEAC=2.42).The total phenolic content(Folin-Ciocalteu method)and the methanolic extract of the lyophilized F.ceranoides collected from a low salinity habitat exhibited the highest phenolic content(PGE=49.48μg/mg of lyophilized extract)amongst those sampled.Thin layer chromatography(TLC)and Fourier transform infrared spectroscopy(FTIR)were used for the identification of compounds in the extracts.This characterization allowed confirmation that the various extracts contained almost the same compounds but with notable quantitative differences.Based on these results,we conclude that there were differences in the quantity of the compounds due to the effect of salinity.The drying methods used were also found to have influenced the quality of the extracted compounds.
基金was supported by the National Natural Science Foundation of China(No.41371127)the Program for Innovative Research Teams of Fujian Normal University(No.IRTL1205)+1 种基金the Key Sciences and Technology Project of Fujian Province(No.2014R1034-1)the Graduate Innovation Project of the School of Geographical Sciences of Fujian Normal University(No.GY201501)
文摘尽管河口潮汐的沼泽地是到进空气的温室气体的排放的重要贡献者,在二氧化碳之间的关系(公司 <sub>2</sub>), 甲烷(关于河口沼泽地, CH <sub>4</sub>) 排放,和环境因素没彻底地被澄清。这研究调查了从一块淡水沼泽地和在东南的中国,以及他们的大小位于一个副热带的河口的一块略有盐味的沼泽地控制公司 <sub>2</sub> 和 CH <sub>4</sub> 的排放的关键因素。学习时期的持续时间是到 2014 年 10 月的 2013 年 11 月。与从二块沼泽地的 <sub>4</sub> 排出物显示出的实验, CO <sub>2</sub> 和 CH 读季节的领域和孵化相关变化。从两块沼泽地的公司<sub>2</sub>和 CH <sub>4</sub>排出物与空气/土壤温度表明了重要积极关联( p ?</sup>并且那么<sub>4</sub><sup>2?</sup>( p ?在在副热带的河口的淡水和略有盐味的沼泽地之间的 2 </sub>排出物,而在在二个地点之间的 CH <sub>4</sub>排出物有差别( p ?从河口淡水沼泽地的 4 </sub>排出物,这些因素关于 incr 在 CO <sub>2</sub>排出物上有小效果这研究的调查结果能为沿着不同咸度坡度估计河口沼泽地的全球温暖贡献有重要含意。
基金Supported by the East Asian Seas Time Series-1 (No. EAST-1), the Ministry of Oceans and Fisheries, Korea, the "'Development of Microbial Metagenomic Techniques for a Fine-Scale Seawater Mass Analysis" through the Ministry of Education of the Republic of Korea, and the National Research Foundation of Korea (No. NRF-2013R 1A 1 A2006915)
基金This work was supported by the National Natural Science Foundation of China (Nos. 21171171, 21434003, and 91427303), and the Key Research Program of the Chinese Academy of Sciences (No. KJZD-EW-M03).
基金supported by the National Natural Sciences Foundation of China (Nos. 31000185, 41076069)
the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA11020205).
文摘Spatial distribution and temporal dynamics of phytoplankton community and their relationships with environmentalfactors were studied in the Pearl River Estuary (PRE), South China, in three seasons. Salinity was considered as the key environ-mental variable controlling horizontal distributions of phytoplankton community composition. A transition from dominance offreshwater diatoms (Aulacoseira granulata and A. granulata v. angustissima) to estuarine species (Skeletonema costatum and Pseu-donitzschia delicatissima) was observed in the high flow season (summer) along the estuary gradient; in the low flow season (spring),the inner estuary was relatively homogeneous and some typical estuarine species could be found near the river mouth. In the normalflow season (autumn), a potentially toxic bluegreen species, Microcystis spp. was predominant in the middle reaches of the estuary,which should be seeded from upstream and transported downstream by river discharges. Phytoplankton abundance was negativelycorrelated with suspended solid content and nutrient concentration in the PRE, suggesting that turbidity and nutrient availability werethe crucial factors regulating the algal biomass. Phytoplankton abundance in the outer estuary was enhanced by increasing irradianceand continued to be enhanced until phosphorus-limitation.