Dissolved Folin Phenol Active Substances (Tannin and Lignin) in the Seawater along the West Coast of India

Information on the distribution of dissolved Folin phenol active substances (FPAS) such as tannin and lignin in the seawater along the west coast of India is provided. Notable amounts of FPAS (surface concentrations: 80 g/l to 147 g/l and bottom concentrations: 80 g/l to 116 g/l) were detected in the seawater along the coast. The distribution pattern brings about a general depth-wise decrease. A seaward decrease was observed in the southern stations whereas reverse was the case in northern stations. A significant negative correlation was observed between FPAS concentration and dissolved oxygen in sub-surface samples. The appreciable amounts of FPAS detected in the coastal waters indicate the presence of organic matter principally originating from terrestrial (upland and coastal marsh) ecosystems in the marine environment. In this context, they may be used as tracers to determine the fate of coastalborn dissolved organic matter in the ocean and to determine directly the relationship between allochthonous and autochthonous organic matter.     

南海北部石油开发区海水中腐殖质和乙醇可溶物的分布

研究了南海北部近岸石油开发区海水的腐殖质(HS)和乙醇可溶物(ES)等有机物的分布行为及其与环境的关系。指出HS和ES的季节变化,平面和垂直分布状况以及它们与浮游动植物的关系等。它们浓度的变化范围为80—500μg/L之间。为海洋石油开采环境的质量监测和海洋生态环境提供数据。     

海洋心血管药物及活性物质的研究现状与展望

按照海洋心血管活性成分的化学分类，本文较系统地列举了该领域中的研究成果和动态，对有代表意义的重点药物作较详细的评述，并探讨了有关海洋心血管药物研究工作的特点及发展前景。     

Binding of thorium(IV) to carboxylate, phosphate and sulfate functional groups from marine exopolymeric substances (EPS)

Th(IV) isotopes are important proxies in oceanographic investigations, and are used as tracers of particle dynamics and particulate organic matter (POC) fluxes out of the euphotic zone through the use of ²³⁴Th/POC ratios. These approaches rely on empirically determined and variable POC to ²³⁴Th ratios, which might be controlled, in parts, by the abundance of exopolymeric substances (EPS). EPS contain acidic polysaccharides (APS) and are excreted by both phytoplankton and bacteria. To this end, radiotracer experiments with EPS from microbial cultures were conducted to determine the binding environment of ²³⁴Th(IV)-binding ligands in colloids and suspended particles in marine systems. In these experiments, the ²³⁴Th distribution during isoelectric focusing (IEF) and polyacrylamide gel electrophoresis (PAGE) was related to the functional group composition of EPS and of colloidal organic matter (COM) isolated from the Gulf of Mexico (GOM) using cross-flow ultrafiltration. EPS was extracted from phytoplankton (Emiliania huxleyi and Synechococcus elongatus) and bacteria (Sagittula stellata and Roseobacter gallaeciensis) cultures by repeated alcohol precipitation. Phosphate and sulfate concentrations were determined using ion chromatography (IC). IEF profiles indicated that 49% to 65% of the ²³⁴Th-labeled EPS from plankton and bacteria as well as COM samples from the GOM was found concentrated below pH of 4, near an isoelectric point, pH_IEP, of about 2. The carboxylic acid maxima for extracted EPS and COM samples appeared close to the pH_IEF of ²³⁴Th(IV). The phosphate maximum appeared at the same pH_IEF as ²³⁴Th(IV) for EPS from R. gallaeciensis and S. elongatus. The sulfate maximum was found at the same pH_IEF as ²³⁴Th(IV) for EPS from S. elongatus and COM. The molecular weight (MW) of the strongly Th(IV)-binding ligand varied from 1 to 14 kDa, depending on the species, but was about 10 kDa in COM. Thus, depending on the species of plankton or bacteria, the MW and specific functional group composition of the strongly ²³⁴Th(IV)-binding amphiphilic biomolecule can vary. Therefore, different acidic functional groups can, at times, contribute to the binding of Th(IV) to the EPS chelating ligand, which can also have different MWs. This implies that the binding environment for Th(IV), which is present at total concentrations at least a million times lower than the acid functional groups, consists of strong polydentate chelate complexes in clustered structures of carboxylate, sulfates and/or phosphates. The combination of strongly chelating groups and amphiphilicity gives this biomolecule the unique properties of a “sticky” ligand.     

褐藻中活性物质研究概况

对近年来从褐藻中发现的有活性的多糖类、脂类、含氮类、萜类、甾醇类、类胡萝卜素、酶类、激素及其他活性物质进行综述。     

Surface-active substances on rainwater and atmospheric particles

The surface tension lowering by surface-active substances has been measured on rainwater, melted snow, and dispersions of atmospheric particles in water, with a film balance and a tensiometer. The precipitation water was sampled during 1979, 1980, and 1981 in the city of Frankfurt/Main. From measurements with the film balance technique, normalized concentrations of insoluble and weakly soluble surface-active substances have been estimated. Soluble surface-active substances were determined from measurements with a tensiometer. It was found that the normalized concentration of theinsoluble and weakly soluble surface-active material on rainwater or melted snow shows a maximum during late spring of about 2.5 · 10⁻⁷ moles/l and a minimum during wintertime of about 5 · 10⁻⁸ moles/l. These concentrations are too low to influence significantly the condensation of water vapour on cloud droplets or the evaporation of water from them. Thesoluble surface-active material on rainwater or melted snow was found to have concentrations of the order of 2 · 10⁻⁶ moles/l. These concentrations are also too small to have a significant influence on cloud physical processes.     

Imposex levels in the dogwhelk Nucella lapillus (L.)—continuing improvement at high latitudes

In 1990, restrictions on the use of tributyltin (TBT)-based antifouling paints were implemented in Iceland. A previous study showed that the level of imposex in the dogwhelk, Nucella lapillus, in Icelandic waters had decreased significantly between 1992 and 1998. In this study, we repeated the survey on imposex in N. lapillus at 33 locations from the Icelandic coast in 2003. The results indicated that both Vas Deferens Sequence Index (VDSI) and Relative Penis Size Index (RPSI) had further declined in 13 locations since 1998. Among these 13 sites, RPSI was reduced to zero in five cases. While improvements from 1992/1993 to 1998 were seen in reduced levels of imposex near both large and small harbours, the pattern from 1998 to 2003 was somewhat different, with improvement mainly observed near smaller harbours. No significant changes in imposex levels near larger harbours occurred over this period. Although the imposex levels still remain high near the large harbour complexes in Reykjavík and Hafnarfjörður, it is evident that regulations, including the use of less toxic antifouling paints and community action, have lead to substantial improvements in the marine environment of Iceland. International Maritime Organisation’s ban on the application of TBT after 2003 is apparently necessary to allow further improvements in larger harbours. The environmental effects of new antifoulants replacing TBT need to be further evaluated.     

微波干燥法快速测定湖盐的水不溶物

简述了盐业生产过程中水不溶物检测方法对实现工业盐生产质量过程控制的影响,提出微波加热快速测定工业盐产品中的水不溶物的方法,通过实验证明,该方法简便迅速,具有很强的实用性。