Production of drinking water from raw water containing cyanobacteria--pilot plant studies for assessing the risk of microcystin breakthrough

Toxins in cyanobacteria are a recognized risk in the treatment of drinking-water treatment. Cyanotoxins can occur in two modifications: cell bound and dissolved in water. The process of toxin release may occur naturally, but it also may be induced through the processes of drinking-water treatment. Both causes of release are relevant to the safety of drinking water. This study investigated cyanotoxin release and elimination through different treatment trains in systematic pilot-scale studies with water from the Weida Reservoir, in Thuringia, Germany. The Weida Reservoir is a dimictic mesoeutrophic reservoir typical for a number of mountainous areas in Europe, with Planktothrix rubescens as the dominant phytoplankton species, and shows a characteristic seasonal pattern of population development and microcystin occurrence. To assess the risk of microcystin breakthrough, the pilot-scale results as well as results of laboratory-scale experiments were used for developing a kinetic model of toxin release in relation to elimination. By calculating removal efficiency of total microcystins (cell bound and dissolved) for different treatment trains, raw water quality was related to the quality targets for finished water, and breakthrough risks could be calculated for given treatment trains and varying cyanobacterial population densities in the reservoir.     

Conformation and complexation with metal ions of cyclic hexapeptides: cyclo (l-Leu-l-Phe-l-Pro)2 and cyclo (l-Cys(Acm)-l-Phe-l-Pro]2

Cyclic hexapeptides, cyclo (l -Leu-l -Phe-l -Pro)₂ and cyclo[l -Cys(Acm)-l -Phe-l -Pro]₂, in which Acm represents an acetoamide-methyl group, were synthesized, and the conformation and complexation with metal ions were investigated. Cooperation of the carbonyl groups of the Cys(Acm) side chains with those of the cyclic skeleton in complexation was especially examined. Cyclo(l -Leu-l -Phe-l -Pro)₂, which possesses no functional groups on side chains, was taken as the reference compound. ¹³C- and two-dimensional n.m.r. measurements revealed that cyclo(l -Leu-l -Phe-l -Pro)₂ and cyclo[l -Cys(Acm)-l -Phe-l -Pro]₂ took a C₂-symmetric conformation contaIntng cisl -Phe-l -Pro bonds in chloroform and acetonitrile. Both cyclic hexapeptides were found to complex selectively with Ba²⁺ and Ca²⁺ in acetonitrile. On complexation the conformation of either cyclic hexapeptide changed into a similar one. However, the binding constant of cyclo[l -Cys(Acm)-l -Phe-l -Pro]₂ was higher than that of cyclo(l -Leu-l -Phe-l -Pro)₂. The n.m.r. measurements showed that the amide carbonyl groups of Cys(Acm) side chains as well as those of cyclic skeleton in cyclo[l -Cys(Acm)-l -Phe-l -Pro], cooperatively bound the cations.     

五味子科植物三萜类化学成分研究进展

对近几年来从五味子科植物中分离到的三萜类成分及药理作用等方面的研究进行综述,并根据萜类成分的结构按其所属的基本骨架进行了分类整理,为五味子科植物的研究提供帮助.     

A new morphospecies of Microcystis sp. forming bloom in the Cheffia dam (Algeria): seasonal variation of microcystin concentrations in raw water and their removal in a full-scale treatment plant

Toxic cyanobacterial blooms are an increasing problem in Algeria. The production of cyanotoxins (microcystins) and their presence in drinking water represent growing hazards to human health. In this study, seasonal variations in the concentrations of total microcystins and physicochemical parameters (pH, temperature, dissolved oxygen, nitrate, orthophosphate, and chlorophyll-a) were analyzed in the Cheffia dam (Algeria), mainly used to supply drinking water. The removal of cyanobacterial cells and microcystins was also evaluated in full-scale plant associated with the Cheffia reservoir. The levels of microcystins (MCYSTs) in both raw and drinking water were evaluated using the protein phosphatase type 2A (PP2A) inhibition test as MCYST-LR equivalents. Identification of microcystin variants was achieved by LC/MS/MS. During the period of study (March-December 2004), microscopic observation showed the dominance in the autumn months (September-November) of a new morphospecies of Microcystis sp. The MCYST-LR equivalent concentrations in raw water varied between 50.8 and 28,886 ng L(-1). The highest level of toxins was observed in October 2004 and was significantly correlated with the chlorophyll-a. Three variants of microcystins assigned as microcystin-YR (MCYST-YR), microcystin-LR (MCYST-LR), and 6Z-Adda stereoisomer of MCYST-LR were observed in the crude extract of the Microcystis sp. bloom sample. During the bloom period, total elimination of Microcystis sp. and toxins were achieved through a classical treatment plant comprised of coagulation and flocculation, powdered activated carbon at 15 mg L(-1), slow sand filtration and chlorination before storage.     

Interaction Between Ciprofloxacin and Metal Cations: Its Influence on Physicochemical Characteristics and Antibacterial Activity

Pharmaceutical Research -     

羊胎免疫调节因子生物活性的研究

目的探讨不同相对分子质量 (Mr)及不同工艺方法获得的山羊羊胎免疫调节因子 (GEIF)生物活性效果。方法运用Ea玫瑰花环试验和T淋巴细胞转化试验进行对比分析。结果超滤法提取GEIF ,不同Mr(30 0 0、5 0 0 0和 10 0 0 0 )Ea玫瑰花环恢复率和T淋巴细胞转化率之间没有明显差异 ;超滤法提取GEIF ,Ea玫瑰花环恢复率和T淋巴细胞转化率均高于透析法。结论采用超滤法提取GEIF生物活性优于透析法 ,不同Mr 提取GEIF生物活性无明显差异。     

2-位取代苯并呋喃类化合物的生物活性及合成研究进展

苯并呋喃衍生物是当前研究杂环芳香族化合物的热点之一。据文献报道该类化合物具有抗肿瘤,抗氧化,钙内流阻滞,血管紧张素II受体拮抗,腺苷A1受体拮抗,抗真菌、抗菌活性和血小板聚集拮抗等药理作用。由于苯并呋喃具有广泛活性,因此吸引很多学者对其进行研究。为了更好地研究该类化合物的合成和生物活性,本文对近几年来文献报道的具有良好生物活性的2-位取代苯并呋喃衍生物进行综述,并对它们的合成方法进行概括,为开发新型2-取代苯并呋喃类化合物提供参考。     

Conformational properties and metal ion transport by synthetic cyclic octapeptide cyclo(D-Leu-L-Pro)4

Cyclo(D-LeU-L-PrO)₄ was synthesized and investigated on conformation, complexation with cations, and cation transport through liquid membrane. Cyclo(D-Leu-L-Pro)₄ was found to take a C₂-symmetric conformation in CDCl₃ solution. However, the intramolecular transformation of conformation was so rapid on n.m.r. time scale that it appeared to take a C₄-symmetric conformation in n.m.r. spectrum. Cyclo(D-Leu-L-Pro)₄ formed a complex selectively with Ba²⁺, and the binding constant was estimated to be similar to that of its diastereomer, cyclo(L-Leu-L-Pro)₄. However, the rate of complex formation in solution of CyClO(D-Leu-L-Pro)₄ with Ba²⁺ was much faster than that of cyclo (L-Leu-L-Pro)₄. This is because cyclo(D-Leu-L-Pro)₄ forms the complex without accompanying the isomerization of peptide bonds. The efficiency of cation transport through a CHCl₃ liquid membrane by Cyclo(D-LeU-L-PrO)₄ was similar to that by cyclo(L-Leu-L-Pro)₄, indicating that the rate-determining step of transport should be the diffusion of the complex across the boundary layer between aqueous phase and organic phase.     

甲基丁香酚的生物学活性及其作用机制的研究进展

甲基丁香酚是一种广泛存在的苯丙素类天然化合物,具有镇痛、麻醉、抗过敏、抗炎、抗氧化和抗肿瘤等多种生物学活性,可能在促进细胞再生、抗衰老和炎症、肿瘤相关性疾病的防治中具有重要研究价值.充分了解甲基丁香酚的结构和作用特点,避免不必要的毒副作用发生,对其开发利用具有重要意义.综述了甲基丁香酚的生物学活性及其作用机制,以期为甲...     

Influence of methylation of the histidine ring of [Sar1]angiotensin II on conformation and biological activity

[Sar¹His(1-Me)⁶]ANG II and [Sar¹His(3–Me)⁶]ANG II were synthesized by the solid-phase method and purified by reversed-phase HPLC. ¹H-NMR spectroscopy at 400 MHz demonstrated the presence of two major conformers for both peptides in DMSO, representing cis and trans isomers (ratio 1:3 and 1:4, respectively) due to restricted rotation at the His-Pro bond. The contractile activities of these peptides in the rat isolated uterus assay were <0.1 and 27% of that of ANG II, respectively. The bioactivities of these analogues were mirrored in their NMR spectra: the inactive analogue [Sar¹His(1-Me)⁶]ANG II showed perturbations of the Sar and His residues which were not present for [Sar¹His(3-Me)⁶]ANG II and the reference agonist [Sar¹] ANG II. The high activity of the analogue methylated at His N₃ suggests that an ionizable imidazole proton is not an absolute requirement for expression of biological activity by angotensin ligands, and that the imidazole group in the molecule may function in an ion dipole-based mechanism when an intramolecular proton transfer (charge relay) mechanism is not available. The biological activity of the ligand appears to depend on the degree of proton transfer from Tyr-OH to the imidazole acceptor, wherein complete (formal) proton transfer represents 100%, activity.     

Synthesis and biological evaluation of resveratrol derivatives with anti-breast cancer activity

Resveratrol is a natural phytoestrogen produced by plants to protect themselves from injury, UV irradiation, and fungal attack. The main active structure is E-resveratrol, which has many pharmacological activities. As the structure of resveratrol is similar to the natural estrogen 17β-estradiol and the synthetic estrogen E-diethylstilbestrol, resveratrol is used in reducing the incidence of breast cancer. However, the therapeutic application of resveratrol is limited due to its low bioavailability. To improve its bioavailability and pharmacological activity, some resveratrol derivatives have been designed and synthesized by substitutions of methoxy, hydroxyl, and other functional groups or heterocyclic esterification either on the “A” or “B” ring, and double bonds were replaced by imine bonds and isometric heterocycles such as naphthyl and imidazole, or synthetic resveratrol oligomers. The structures, synthetic routes, and evaluation of the biological activities of these compounds are discussed. These are aimed at providing some references for the study of resveratrol derivatives in anti-breast cancer treatment.     

重组人白细胞介素11生物学活性测定方法研究

目的建立重组人白细胞介素 11(rhIL 11)生物活性测定方法。方法运用单克隆方法筛选出rhIL 11敏感细胞株T 10 ,采用溴化四唑蓝比色法进行rhIL 11生物活性测定 ,采用四参数方程对测定结果进行计算。结果以世界卫生组织国际标准品作为参照品 ,与美国Genetics公司rhIL 11上市产品NeumegaTM进行测定比较 ,结果显示国内同类产品与其生物活性一致 ,RSD均小于 10 %。结论此方法可用于rhIL 11生物活性测定     

Effect of irrigation with lake water containing microcystins on microcystin content and growth of ryegrass, clover, rape, and lettuce

The effect of irrigation with lake water containing a variety of microcystins on accumulation of toxins, or toxin metabolites, and plant growth in ryegrass, clover, rape, and lettuce, was investigated in a glasshouse experiment. The plants were grown in sand culture and received either three or six applications of lake water, which was applied either directly to the sand surface or to the plant shoots. As determined by LC-MS, each plant received 170 mug of a mixture of 10 different microcystins per application. Microcystins in plant samples were extracted with 70% methanol and analyzed by Adda-specific ELISA. For the shoot application treatment, microcystins were not present at measurable levels in shoots of ryegrass or rape, but were present in lettuce [0.79 mg/kg dry weight (DW)] and clover (0.20 mg/kg DW). Total microcystin concentration in roots did not vary greatly depending on whether treatment water was applied directly to the sand, or reached the roots via run-off from the shoots. Microcystins in roots were highest in clover (1.45 mg/kg DW), intermediate in lettuce (0.68 mg/kg DW) and low in ryegrass (0.20 mg/kg DW), and rape (0.12 mg/kg DW). There was no evidence for root-to-shoot translocation of microcystins. Three applications of microcystins reduced shoot DW of ryegrass, rape and lettuce, and increased root DW of ryegrass and lettuce. Clover DW was not changed by treatment with microcystins. The results show that irrigation with water containing microcystins has the potential to move microcystins into farm animal and human food chains at concentrations that can exceed recommended tolerable limits.     

3-DG生物活性及其与临床疾病关系研究进展

3-脱氧葡糖醛酮（3-Deoxyglucosone,3-DG）是～种高反应性毒性2一羰基醛化合物,能通过非酶糖基化（Maillard反应）、果糖胺-3-激酶（Fructoseamine-3-kinase,F3K）途径及多元醇通路形成,同时能脱毒代谢成3-脱氧果糖和3-脱氧葡萄糖醛酸（2-keto-3-deoxyglucosonicacid,3-DGA）。近年来研究报导,3-DG在衰老、糖尿病、尿毒症等许多临床疾病的发生、发展中起着重要作用。本文从3-DG的生成代谢过程、生物活性及其与临床疾病的关系等方面作一综述。     

两色金鸡菊化学成分及生物活性研究进展

目的综述两色金鸡菊化学成分及相关生物活性的研究进展。方法系统查阅国内外相关两色金鸡菊的研究文献,进行综合分析。结果两色金鸡菊富含多种对人体有益的化学成分,并具有多样的生物学活性。结论两色金鸡菊具有潜在的药用和食用开发价值,值得更进一步研究。     

BMP调控成骨细胞生物活性的实验研究

目的 探讨骨形态发生蛋白（bone morphogenetic protein,BMP）对培养的正常人成骨细胞主要生物学行为的影响。方法分别以0．02、0．1、1μg/m3种浓度的BMP作用于成骨细胞,通过MTY法了解BMP的效应。以0．1μg/ml浓度的BMP作用于成骨细胞,测定BMP对成骨细胞碱性磷酸酶（alkaline phospbatase,ALP）活性及骨钙素（bone gla protein,BGP）合成等主要生物学特性的影响。结果BMP作用于成骨细胞,能促进ALP活性及BGP的合成。结论BMP能促进成骨细胞活性,并且其促进成骨增殖的效能具有浓度依赖性。     

1H-吡咯-2(5H)-酮类化合物的合成及生物活性

目的研究5位连有取代苯基的1H-吡咯-2(5H)-酮类化合物生物活性。方法在吡咯酮的5位引入各种取代苯基,合成出目标化合物,所有化合物1H NMR和MS等谱确证;通过荧光偏振法测定化合物对蛋白的抑制常数Ki。结果所有13个目标化合物都能抑制蛋白的结合,其中化合物4e的Ki达到阳性对照药的5倍。结论 5位苯环的取代基团对活性影响很大,吸电子基团取代活性高于亲电子基团,其中硝基取代活性最强。     

Influence of the cyanotoxin microcystin-LR on tocopherol in Alfalfa seedlings (Medicago sativa)

Spray irrigation of crop plants can represent a risk if the water is contaminated with cyanotoxins. These secondary metabolites produced by many cyanobacteria can have adverse effects on organisms, among others the induction of excess oxygen radicals, so-called oxidative stress. Thereby tocopherol as a lipid antioxidant is essential to maintain membrane integrity. In this study the effects of the cyanotoxin microcystin-LR (MC-LR), and a Microcystis crude extract (Mic-CE) containing MC-LR on tocopherol content and gene expression of Homogentisate phytyltransferase (HPT), involved in tocopherol synthesis, were investigated in seedlings of the crop plant Medicago sativa.Exposures to environmental relevant concentrations showed that Mic-CE affects the tocopherols at a lower concentration than the pure toxin. Changes during a 3-day exposure using 0.5 μg L⁻¹ MC-LR and Mic-CE revealed strong increases of α- and β-tocopherol content, whereas the influence on β-tocopherol was far stronger than on α-tocopherol. The HPT mRNA was elevated after 24 and 72 h exposure to MC-LR.These results show that also low concentrations of cyanobacterial toxins in the water have strong influence on tocopherol in M. sativa seedlings and therefore represent a stress for the plants.