Xyloketal H from the mangrove endophytic fungus Xylaria sp. 2508

(3R*,3aR*,9aR*)-3,9a-Dimethyl-2,3,3a,9a-tetrahydro-4H-furo[2,3-b]chromene-5,7-diol (xyloketal H), a representative of a new family of xyloketals, was isolated from the marine-derived mangrove fungus Xylaria sp. 2508. Its structure was elucidated by spectroscopic data and single-crystal X-ray diffraction analysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1051–1052, June, 2006.     

Xyloketal G,a Novel Metabolite from the Mangrove Fungus <Emphasis Type="Italic">Xylaria sp.</Emphasis> 2508

A novel metabolite 1, named xyloketal G, was isolated from cultures of marine derived mangrove fungus Xylaria sp. 2508. Its structure was elucidated by analysis of spectroscopic data.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 22–23, January–February, 2005.     

红树林湿地土壤矿物的分析

以湛江湾南海堤典型红树林湿地土壤为研究对象,采用X射线衍射(XRD)和傅立叶变换红外光谱(FTIR)快速批量鉴定土壤中矿物成分,利用扫描电子显微镜(SEM)观察土壤颗粒形貌特征并获得化学成分组成信息;同时采集附近光滩土壤样品进行对比研究,以揭示红树林湿地土壤特殊的生态环境特征。结果表明,红树林湿地土壤矿物主要由高岭石、石英、白云母、埃洛石、地开石和蛇纹石等组成;与光滩土壤相比,红树林湿地土壤矿物类型多样,而光滩土壤矿物相对单一,主要为石英和高岭石;红树林湿地土壤颗粒以片状聚合体为主,主要元素组成为C、O、S、Al、Si、Mg、Fe等,常见含有Cu、Zn、Mo等重金属元素。同时发现红树林湿地土壤颗粒含有较丰富的硫化物;而光滩土壤未发现上述特征,表明红树林湿地处于一个特殊的生态环境,土壤沉积物中富含有机质、Fe、S等,比一般潮滩更易于富集硫化物或重金属。     

A new compound: Xyloketal H from mangrove fungus <Emphasis Type="Italic">Xylaria</Emphasis> sp. from the South China Sea coast

A new metabolite xyloketal H (1), was isolated from mangrove fungus Xylaria sp. (No.2508) obtained from the South China Sea. By spectroscopic analyses, primarily 2D NMR methods and X-ray diffraction experiments, its structure was elucidated. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 5–6, January–February, 2008.     

梯田式人工湿地出水致突变性研究

应用蚕豆根尖细胞微核技术对梯田式人工湿地出水进行致突变性研究，测定了生活污水、梯田式人工湿地出水、常规垂直流人工湿地出水及自来水的蚕豆根尖细胞微核千分率（MCN‰）及污染指数（PI），并对各水样的MCN‰进行了舱验．结果表明：梯田式人工湿地出水的致突变性（MCN％。为1.8‰）与生活污水（MCN‰为10．2‰）有显著差异，低于常规垂直流人工湿地（MCN‰为3．2‰），与自来水无明显差异（MCN‰为1．6‰），出水无致突变性，具有安全性．     

A new biphenyl derivative from an unidentified marine fungus E33

A new biphenyl derivative 3,5′-dihydroxy-4′,5-dimethoxy-2′-methyl-[1,1′-biphenyl]-2-carboxylic acid methyl ester (1), was isolated from the culture broth of a fungus isolated from the rhizosphere soil of mangrove root on the South China Sea. The structure of 1 was determined by comprehensive spectroscopic methods, primarily 2D NMR techniques. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 128–129, March–April, 2008.     

Thermodynamic Study of the Extraction of Inorganic Mercury Compounds in Fish Species of the International Anzali Wetland,Iran

Inorganic mercury concentration was measured in the muscle tissues of four types of fish in the aquatic international Anzali Wetland ecosystem in Guilan. In the same ecosystem, the northern pike is able to concentrate inorganic mercury in its body more than other fish. In each species, a fish with the highest amount of inorganic mercury was selected for determination of thermodynamic parameters of inorganic mercury extraction using calculation of the equilibrium constant and fitting of ln K_c versus inverse temperature at the atmospheric pressure. The origins of thermodynamic parameters were discussed. The extraction processes were done in the range of temperatures from 331.15 to 365.15 K and at atmospheric pressure. Results show that the extraction of mercury compounds from SH groups of sulfhydryl proteins in fish muscle tissue is an endothermic process with a positive value for entropy and Gibbs free energy changes at room temperature.     

三维荧光光谱-平行因子法解析再生水补给人工湿地DOM的光谱特征

采用三维荧光光谱技术和平行因子分析,对北方某潜流-表流复合人工湿地水体中溶解性有机质（DOM）的光谱特征、演变过程及其来源进行研究,以期为深入理解人工湿地的作用机理和污染物溯源提供科学依据。结果表明,人工湿地中各阶段的出水呈现相似的三维荧光特性,均出现明显的类腐殖质尖峰和类蛋白峰,但强度有所不同。混凝沉淀对类蛋白和类腐殖质两种DOM的荧光强度均有一定的削减作用;潜流湿地出水的荧光图谱显示,微生物代谢副产物和类色氨酸等类蛋白峰强度明显降低,而类腐殖质峰强度无明显变化,这表明潜流湿地对再生水中的类蛋白物质具有明显的降解作用,而对类腐殖质物质降解效果较弱;相反,在表流湿地出水的荧光图谱中发现类蛋白峰和类腐殖质峰的强度均削弱,而且在表流湿地下游3 km处的强度达到最低。这一趋势归因于潜流湿地中滤料表面生物膜对DOM的生物降解以及表流湿地内部活跃的微生物活动和水生植物的根系对DOM的吸附作用。平行因子分析结果显示,该湿地水体DOM中包含5个荧光组分,分别为类富里酸组分C1（240, 330/430 nm）、微生物活动相关的类腐殖质组分C2（285, 330/380 nm）、类色氨酸C3（230/350 nm）、微生物代谢副产物C4（280/320 nm）和陆源类腐殖质C5（270, 380/470 nm）。采用多种荧光光谱指数对湿地中DOM的来源进行解析,荧光指数和自生源指数均表明该湿地中DOM的来源以生物代谢输入为主,而陆源输入的影响较小;腐殖化因子则表明该湿地存在弱腐殖化的特征且生物来源占主导地位。斯皮尔曼相关性分析表明5个荧光组分具有同源性,而且与水中氮元素的迁移转化密切相关。     

复合垂直流构建湿地中生物膜的空间分布、特性和降解性能

对复合垂直流构建湿地基质不同层次进行采样，测定了生物膜的空间分布、脱氢酶活性、呼吸强度、间隙水总有机碳、发育时间及五氯酚的去除率等指标．结果表明，基质生物膜发育良好，可挥发性固体均值达到0．0218．从下行池整体看，生物膜生物量、呼吸强度、脱氢酶活性及有机污染物去除能力都较上行池高，下行池为污水中有机物的主要降解空间．不同层次生物膜的空间分布存在着差别，生物膜主要积累在0～10cm表层，其脱氢酶活性、呼吸强度高于其他各层次，各指标在变化趋势上存在明显的一致性．生物膜的发育时间直接影响着其对有机碳的降解能力，从10天到70天，降解率提高了5倍．其生物膜基质对五氯酚的去除率是无生物膜基质的1．5倍．     

Degradation of medium-chain-length polyhydroxyalkanoates in tropical forest and mangrove soils

Bacterial polyhydroxyalkanoates (PHAs) are perceived to be a suitable alternative to petrochemical plastics because they have similar material properties, are environmentally degradable, and are produced from renewable resources. In this study, the in situ degradation of medium-chain-length PHA (PHA_MCL) films in tropical forest and mangrove soils was assessed. The PHA_MCL was produced by Pseudomonas putida PGA1 using saponified palm kernel oil (SPKO) as the carbon source. After 112 d of burial, there was 16.7% reduction in gross weight of the films buried in acidic forest soil (FS), 3.0% in the ones buried in alkaline forest soil by the side of a stream (FSst) and 4.5% in those buried in mangrove soil (MS). There was a slight decrease in molecular weight for the films buried in FS but not for the films buried in FSst and in MS. However, no changes were observed for the melting temperature, glass transition temperature, monomer compositions, structure, and functional group analyses of the films from any of the burial sites during the test period. This means that the integral properties of the films were maintained during that period and degradation was by surface erosion. Scanning electron microscopy of the films from the three sites revealed holes on the film surfaces which could be attributed to attack by microorganisms and bigger organisms such as detritivores. For comparison purposes, films of polyhydroxybutyrate (PHB), a short-chain-length PHA, and polyethylene (PE) were buried together with the PHA_MCL films in all three sites. The PHB films disintegrated completely in MS and lost 73.5% of their initial weight in FSst, but only 4.6% in FS suggesting that water movement played a major role in breaking up the brittle PHB films. The PE films did not register any weight loss in any of the test sites.