1种绿藻硫酸多糖的化学组成及其结构研究

目的 对1种绿藻硫酸多糖的化学组成及其结构特征进行研究。方法 通过热水提取法,从1种石莼属海藻中提取硫酸多糖,采用强阴离子交换色谱和凝胶渗透色谱对多糖进行分离纯化;采用高效凝胶渗透色谱(HPGPC)、高效液相色谱以及化学方法对多糖的纯度、分子量、单糖组成和化学成分进行分析测定;通过红外光谱和气质联用方法对多糖的结构进行表征。结果 多糖HP2S在HPGPC色谱图上呈单一对称峰,分子量为90.5 kDa,硫酸根和糖醛酸含量分别为32.1%和7.4%,HP2S主要由鼠李糖组成,含有少量葡萄糖、葡萄糖醛酸、半乳糖和木糖,HP2S糖链中鼠李糖主要存在形式为(1→2)-Rhap 、(1→3)-Rhap 和(1→2, 3)-Rhap,硫酸根位于(1→3)-Rhap 的C-2位或(1→2)-Rhap 的C-3位上。结论 水溶性多糖HP2S是1种结构新颖的主要由鼠李糖组成的硫酸化多糖。     

绿藻硫酸多糖UCS2的结构及抗凝血活性研究

目的 对绿藻多糖UCS2的结构特征和抗凝血活性进行研究。方法 通过冷水提取、强阴离子交换色谱和凝胶渗透色谱,从绿藻花石莼中提取分离得到硫酸多糖UCS2;采用高效凝胶渗透色谱（HPGPC）、高效液相色谱、红外光谱和气质联用色谱对多糖UCS2的结构进行表征;通过活化部分凝血活酶时间（APTT）、凝血酶时间、凝血酶原时间对多糖UCS2体外抗凝血活性进行研究。结果 绿藻多糖UCS2分子量为39.55kDa,硫酸根和糖醛酸含量分别为19.74%和18.66%;UCS2主要由鼠李糖组成,含有少量葡糖醛酸和木糖。糖链中含有→3,4)-α-L-Rhap-(1→, →4)-α-L-Rhap-(1→, →4)-β-D-Xylp-(1→和→4)-β-D-GlcAp-(1→,硫酸基位于→4)-α-L-Rhap-(1→的C-3位。多糖UCS2对APTT有显著延长作用,具有较高的抗凝活性。结论 绿藻多糖UCS2是1种抗凝活性的葡萄糖醛酸-木糖-鼠李糖型硫酸多糖。     

海藻多糖UH3的结构特征、抗凝和溶栓活性研究

目的 对海藻多糖UH3的结构特征、抗凝血和溶栓活性进行研究。方法 通过热水提取法，从海藻中提取硫酸多糖，采用强阴离子交换色谱和凝胶渗透色谱对多糖进行分离纯化；采用高效液相色谱、高效凝胶渗透色谱（HPGPC）、红外光谱及甲基化方法对多糖的结构进行表征；通过活化部分凝血活酶时间（APTT）、凝血酶时间（TT）、凝血酶原时间（PT）及血凝块溶解法研究多糖体外抗凝血和溶栓活性。结果 多糖UH3在HPGPC色谱图上呈单一对称峰，分子量为50.3 kDa，硫酸根和糖醛酸含量分别为12.27和12.85%；UH3主要由鼠李糖组成，含有少量葡萄糖醛酸和木糖；UH3糖链中鼠李糖主要以→4)-Rhap-(1→、 →3,4)-Rhap-(1→及少量的T-Rhap形式存在，木糖以→4)-Xylp-(1→和T-Xylp存在形式，糖醛酸以→4)-GlcAp-(1→和T-GlcAp形式存在；硫酸根主要位于→4)-Rhap-(1→的C-3位。多糖UH3对APTT和TT有显著延长作用，并能明显提高溶栓率。结论 海藻多糖UH3是一种结构新颖的具有抗凝和溶栓活性的硫酸多糖。     

浒苔多糖的分级纯化及体外抗氧化活性研究

目的研究浒苔多糖及其分级组分的抗氧化活性。方法使用DEAE-Sepharose FF离子交换凝胶层析柱对浒苔多糖进行分级纯化,利用HPLC色谱分析了单糖组成,并研究了其对超氧阴离子、羟自由基、1,1-二苯基苦基苯肼(DPPH)的清除作用和还原能力。结果浒苔多糖主要由鼠李糖和木糖组成,硫酸根主要连接在鼠李糖上。未分级多糖的抗氧化活性要高于其分级纯化组分。当浓度为10.3μg·mL-1时,未分级多糖对超氧阴离子的抑制率为49.8%。结论浒苔多糖具有显著的抗氧化活性。     

褐藻来源硫酸岩藻聚糖的化学组成与结构的研究进展

褐藻硫酸岩藻聚糖是来源于褐藻的结构复杂的一类海洋硫酸多糖,主要由岩藻糖、半乳糖、甘露糖和葡萄糖醛酸组成,并含有少量的木糖、葡萄糖、鼠李糖、阿拉伯糖和氨基葡萄糖。研究表明,褐藻硫酸岩藻聚糖的主链是由 α (1→3) 或 α (1→3)、α (1→4) 交替连接的硫酸化L-岩藻糖构成,还嵌有半乳糖、葡萄糖醛酸等,而厚叶解曼藻和羊栖菜等褐藻硫酸岩藻聚糖的主链是由1→2甘露糖和1→4葡萄糖醛酸构成二糖重复单元。褐藻硫酸岩藻聚糖的主链上普遍存在岩藻糖、半乳糖、甘露糖或葡萄糖醛酸等寡糖的支链,因此糖链结构复杂。硫酸岩藻聚糖的硫酸根位于L-岩藻糖的C-2、C-3或C-4位,也存在C-2,4双硫取代。目前,褐藻硫酸岩藻聚糖结构的分析技术主要为甲基化法分析、核磁共振、二维核磁共振技术和串联质谱分析技术等。本文对褐藻来源硫酸岩藻聚糖的化学组成和结构以及常用分析技术进行了总结,为褐藻硫酸岩藻聚糖的结构分析以及构效关系研究提供依据。     

爆发期条浒苔多糖的提取分离及其理化性质研究

目的从爆发期条浒苔中提取、分离多糖并对其理化性质进行研究。方法对干燥后的条浒苔乙醇脱脂后采用热水和热碱提取,得到了两种条浒苔粗多糖ECP1和ECP2,通过Q-Sepharose FF阴离子交换柱进一步分级,分别从ECP1和ECP2中得到ECP1A～F和ECP2A～F共12种多糖组分。采用高效凝胶渗透色谱法(HPGPC)分析多糖相对分子质量,并用高效离子色谱(HPIC)法分析各组分单糖组成。结果热水和热碱提取粗多糖得率分别为34.87%和14.77%,粗蛋白含量分别为0.39%和1.17%。单糖组成分析表明,多数组分中有高含量的鼠李糖以及不同含量的岩藻糖,葡萄糖,木糖,半乳糖和糖醛酸。ECP1E～F和ECP2E～F中含有较多的葡萄糖醛酸,而ECP1B～D及ECP2D中则含有较多的艾杜糖醛酸。ECP1A、ECP1E和ECP1F以及ECP2A、ECP2E和ECP2F的相对分子质量分别为604、311、45、274、106和277kD;硫酸基含量分别为3.67%、30.39%、17.11%、0.3%、27.63%和15.89%。结论爆发期条浒苔中多糖含量高、蛋白含量低,除了含有鼠李糖和葡萄糖醛酸外,还含有少见的艾杜糖醛酸,尤其不含甘露糖,表明其与常规条浒苔多糖明显不同,是一类值得开发的新多糖资源。     

抗凝血活性海洋硫酸多糖HP1-1的结构研究

目的 对抗凝血活性海洋硫酸多糖HP1-1的结构进行研究。方法 通过高效液相色谱(HPLC)、高效凝胶渗透色谱(HPGPC)、傅里叶变换红外光谱(IR)以及气质联用色谱(GC-MS)和核磁共振波谱(NMR)方法,对抗凝血活性海洋硫酸多糖HP1-1的结构进行解析。结果 海洋硫酸多糖HP1-1的分子量为297 kDa,总糖和硫酸基含量分别为78.1%和12.3%;HP1-1主要由葡萄糖组成,含有少量半乳糖、阿拉伯糖和甘露糖;HP1-1糖链中含有→4)-Glcp-(1→、→3)-Glcp-(1→、→3,4)-Glcp-(1→、→4)-Arap-(1→、→3,4)-Galp-(1→和→3)-Galp-(1→,硫酸基位于→4)-Glcp-(1→的C-3位和→3)-Galp-(1→的C-4位。 结论 海洋多糖HP1-1是主要由葡萄糖组成的硫酸多糖,含有多种糖基连接方式,为独特结构序列的新颖海洋硫酸甘露阿拉伯半乳葡聚糖。     

钝顶螺旋藻酸性多糖的分离纯化和结构分析

本研究从钝顶螺旋藻中分离纯化了酸性多糖,并进行了结构分析.多糖经DEAE-纤维素柱和Sephadex-200凝胶柱纯化得到螺旋藻酸性多糖纯品,HPLC检测纯度达96.7%,分子量均一,约1.62×10~5.TLC和GC分析表明该多糖主要由D-鼠李糖、D-木糖、D-葡萄糖和D-甘露糖醛酸构成,摩尔比为65.5:19.5:9:6.经IR、~(13)C NMR和甲基化分析,推测该多糖可能以1,3-连接的鼠李糖为主链.其中木糖为β构型,鼠李糖、葡萄糖和甘露糖醛酸均为α构型,所有糖基均呈吡喃型.     

绿藻硫酸多糖SHW及其低分子量片段的结构及抗凝活性研究*

目的 对绿藻多糖SHW及其低分子量片段的结构及抗凝活性进行研究。方法 通过热水提取、强阴离子交换色谱和凝胶渗透色谱,从绿藻硬毛藻中提取分离得到硫酸多糖SHW;通过可控酸解方法制备SHW低分子量片段;采用高效凝胶渗透色谱、高效液相色谱、红外光谱及甲基化方法对多糖结构进行表征;通过活化部分凝血活酶时间、凝血酶时间、凝血酶原时间研究多糖SHW及其低分子量片段体外抗凝血活性。结果 多糖SHW及其低分子量片段主要由阿拉伯糖组成,含有少量半乳糖和氨基葡萄糖;糖链中阿拉伯糖主要以→4)-Arap-(1→和→3,4)Arap-(1→的形式存在,半乳糖以→4)-Galp-(1→存在形式,硫酸根主要位于→4)-Arap-(1→的C-3位。SHW及其低分子量片段A1～A6的分子量分别为492 kDa、200 kDa、170kDa、100kDa、26kDa、14kDa 和10 kDa。SHW 具有较高的抗凝血活性,且其抗凝活性随着其分子量的减少而降低。结论 海藻多糖SHW是一种具有抗凝活性的新颖硫酸多糖,其抗凝活性与分子量密切相关。     

从棕色海藻中得到的抗病毒多糖硫酸酯

许多多糖硫酸酯如葡聚糖硫酸酯、肝素、戊聚糖多硫酸酯对HIV培养物都有较强的选择抑制活性。它们可抑制细胞匀浆中的HIV逆转录酶,故其抗病毒活性基本可以肯定是由于阻断了病毒吸附于细胞表面而导致的。作者从黄墨角藻Ascophyllum nodosum(即岩藻)中分出两个岩藻聚糖硫酸酯GXF和Asco。GXF为由葡萄糖醛酸、木糖和岩藻糖组成,分子量约30000,而Asco为一杂多糖混     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.