缢蛏多糖的提取、分离和结构分析

目的从缢蛏中提取和分离纯化多糖,对其基本理化性质和结构组成进行分析。方法依次采用100℃热水提和碱提方法从缢蛏中提取粗多糖,采用Q Sepharose Fast Flow强阴离子交换柱层析和Sephacryl S-300凝胶柱层析对粗多糖进行分离纯化,并对其总糖、蛋白含量,相对分子质量和单糖组成进行分析。对多糖纯化组分采用甲基化、气质联用(GC-MS)、红外光谱(IR)和核磁共振波谱(NMR)进行化学结构解析。结果从缢蛏中经热水提粗多糖(YC-S)和碱提粗多糖(YC-J)均为葡聚糖,进一步分离纯化得到了4种水溶性多糖组分。对其中1种热水提多糖纯化组分YC-S2采用高效液相凝胶色谱法测得其相对分子质量为482kD,且色谱峰单一对称,表明其具有较高的纯度。结构分析表明,YC-S2是1种以α-(1→4)Glc为主链,含有少量的β-(1→3,4)和β-(1→4)分支的D-吡喃型葡聚糖。结论从缢蛏中提取分离得到了4种多糖组分,并初步确定了1种水溶性葡聚糖的结构,为缢蛏多糖结构和活性的深入研究提供了基础。     

一种 β-葡聚糖的结构表征及其体外免疫活性研究

目的 从海茸(Durvillaea antarctica)中提取、分离和纯化β-葡聚糖,并对其结构和体外免疫活性进行研究。方法 将干燥海茸粉碎,经水提取和Q-Sepharose Fast Flow离子交换层析分离得到β-葡聚糖(DAC)。采用硫酸-苯酚法、Folin-酚法、柱前衍生高效液相色谱法和多角度高效凝胶渗透色谱与多角度激光光散射器联用(HPGPC-MALLS)法对DAC的总糖含量、蛋白含量、单糖组成和分子量进行分析,并通过甲基化和气质联用(GC-MS)、傅里叶变换红外光谱(FTIR)和核磁共振波谱(NMR)对其结构进行表征。采用中性红法对DAC的体外免疫活性进行评价。结果 从海茸中分离纯化得到一种总糖含量达97.5%的β-葡聚糖,其蛋白含量和分子量分别为2.0 %和18.3 kDa。经甲基化和NMR分析结果表明,DAC是以→3)Glc(β1→为主链,并含有少量→6)Glc(α/β1→分支的葡聚糖。体外免疫活性结果显示,在浓度为50 μg.mL-1时, DAC对巨噬细胞的吞噬能力达到最大值。结论 海茸β-葡聚糖能显著增强巨噬细胞的吞噬能力,是一种潜在的免疫增强剂。     

红树林内生真菌Trichodermasp.多糖的化学组成和结构表征

目的 对红树林内生真菌Trichoderma sp.菌丝体多糖进行研究。方法 将菌丝体干燥粉碎后,依次采用冷水、热水和热碱提取粗多糖,并采用离子交换柱层析和凝胶渗透柱层析对粗多糖进行分离纯化;通过高效液相色谱(HPLC)、高效凝胶渗透色谱(HPGPC)、红外光谱(IR)以及气质联用色谱(GC-MS)等方法对多糖进行化学组成分析和结构表征。结果 从菌丝体中分离纯化获得5个多糖LPC2-1、LPC3-1、LPR2-1、LPA2-1和LPA3-1,它们的得率分别为32%、41%、28%、36%和47%,分子量分别为15.3, 74.6, 9.5, 19.4和35.2 kDa;这5种多糖均由不同比例的甘露糖、葡萄糖和半乳糖组成,LPR2-1还含有少量的葡萄糖胺;5种多糖的糖链中均含有末端Man、(1,2)-Man、(1,6)-Man、(1,2,6)-Man、(1,2)-Galf和(1,6)-Galf;此外,每种多糖含有其它不同的糖基连接方式。结论 首次从红树林内生真菌Trichoderma sp.菌丝体中分离纯化获得了5种多糖组分,它们的化学组成和结构特征不同,均含有少见的(1,2)-Galf和(1,6)-Galf的连接方式。     

太平洋牡蛎多糖的提取、分离和结构分析

目的　从太平洋牡蛎(Crassostrea gigas)肉中提取和分离纯化多糖,并对其基本理化性质和结构组成进行分析。方法　将牡蛎鲜肉制成丙酮粉,依次采用室温水,60 ℃热水和稀碱提取牡蛎粗多糖,对其总糖含量、蛋白含量和单糖组成进行分析。采用DEAE Sepharose FF阴离子交换和Sephacryl S-400凝胶柱层析对粗多糖进行分离纯化,并对获得的纯化组分采用红外光谱 (IR)、甲基化、气质联用 (GC-MS)、电喷雾质谱 (ESI-MS) 和核磁共振波谱 (NMR) 等方法进行化学结构分析。结果　从牡蛎肉中提取得到了3种牡蛎粗多糖,单糖组成都只含有葡萄糖 (Glc)。对粗多糖进一步分离,得到了5种多糖纯化组分。对水溶性多糖纯化组分 MC-11 的结构进行了分析,表明其是以 →4)-α-D-Glc-(1→ 为主链,含有 →3,4)- β-D-Glc-(1→和 →2,4)- β-D-Glc-(1→ 分支的 D-吡喃型葡聚糖,相对分子质量为1299 kDa。结论　从太平洋牡蛎肉中分离纯化得到了5种多糖组分,并采用多种方法确定了1种纯化组分 MC-11 的结构,为牡蛎多糖结构与活性关系的深入研究提供了基础。     

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。     

海茸多糖的分离纯化与结构表征

目的从海茸(Durvillaea antarctica)中提取分离多糖并对其结构进行表征。方法采用冷水提取,然后用离子交换色谱柱分离纯化得到多糖HRC0和HRC1,用高效凝胶渗透色谱法(HPGPC)测定相对分子质量,用高效液相色谱法(HPLC)测定单糖组成,红外光谱(IR)和核磁共振波谱法(~1H-NMR,~(13)C-NMR)对其化学结构进行表征。结果 HRC0是一种相对分子质量为127.9 kD的线型β-1,3-葡聚糖;HRC1是一种相对分子质量为208.1 kD,且甘露糖醛酸含量高达83%的褐藻胶。结论海茸冷水提取物中主要是β-1,3-葡聚糖和高甘露糖醛酸含量的褐藻胶。     

扁玉螺多糖的提取、分离和结构分析

目的从扁玉螺(Neverita didyma)中提取和分离纯化多糖,并对其基本理化性质和结构组成进行分析。方法依次采用水提和碱提方法从扁玉螺中提取粗多糖,采用DEAE Sepharose FF阴离子交换和Sephacryl S-300凝胶柱层析对粗多糖进行分离纯化,并对其总糖、蛋白、氨基糖、糖醛酸和硫酸根含量,相对分子质量和单糖组成进行分析。对多糖纯化组分采用甲基化、气质联用(GC-MS)、红外光谱(IR)、电喷雾质谱(ESI-MS)和核磁共振波谱(NMR)对其化学结构进行分析。结果扁玉螺水提粗多糖(BYL-S)中不含有糖醛酸和硫酸基,其单糖组成只含Glc,进一步分离得到了4种水溶性多糖组分。碱提粗多糖(BYL-J)单糖组成相对复杂,除含有Glc外,还含有Man、GlcN、GalN、Gal和Fuc,其摩尔比为Glc∶Man∶GlcN∶GalN∶Gal∶Fuc=78.9∶1.7∶3.4∶2.2∶5.2∶5.6,进一步分离得到了3种多糖组分。对水提多糖纯化组分BYL-S2的结构分析表明其是以α-(1→4)为主链,含有少量β-(1→3,4)和β-(1→3)分支的D-吡喃型葡聚糖。结论从扁玉螺中提取分离得到了7种多糖组分,并确定了一种水溶性葡聚糖的结构,为扁玉螺多糖结构和活性的深入研究提供了基础。     

海胆黄多糖的分离、纯化及免疫活性测定

目的从光棘球海胆中分离纯化海胆黄多糖(polysaccharidefromtheeggsofStrongylocentrotusnu-dus,简称SEP),确定其纯度和分子量,并现察其免疫活性。方法海胆黄先经丙酮脱脂,根据正交实验和活性分析确定最佳热水提取条件,然后热水提取、去蛋白、醇沉得海胆黄粗多糖。粗多糖经超滤、DEAESepharoseFastFlow及SephacrylS-400柱层析纯化得多糖精品SEP。经高效液相色谱、聚丙烯酰胺凝胶电泳及纸层析鉴定其纯度。高效凝胶渗透色谱法(HPGPC)测定其分子量。体外脾淋巴细胞增殖实验测定其免疫活性。结果从海胆黄中分离纯化得到的均一多糖组分SEP,经检测其分子量为1950KD左右。脾淋巴细胞增殖实验表明SEP可显著促进脾淋巴细胞的增殖。结论从海胆黄中分离纯化得到的均一多糖组分SEP具有较强的体外免疫活性。     

海洋硫酸多糖PAE的结构和抗病毒活性研究

目的 对肠浒苔来源的硫酸多糖的结构和抗病毒活性进行研究。 方法 通过稀碱提取法,从肠浒苔中提取硫酸多糖,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(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)方法对多糖的结构进行表征;采用细胞病变效应测定PAE对不同病毒的抑制率。 结果 从肠浒苔中分离得到多糖PAE,其分子量为13.98 kDa,主要由鼠李糖、葡萄糖醛酸和木糖构成,糖链主要由(1→4)-Rhap,(1→3,4)-Rhap,(1→2,4)-Rhap,Xylp(1→和(1→4)-Glcp组成,硫酸根主要位于(1→4)-Rhap 的C-2或C-3位以及Xylp(1→的C-4位上,PAE具有良好的抗病毒活性,特别是对呼吸道合胞体病毒的抑制率较高。 结论 海洋多糖PAE是一种结构新颖的由鼠李糖、葡萄糖醛酸和木糖组成的硫酸多糖,具有良好的抗病毒活性。     

平颏海蛇皮中新型硫酸皮肤素的分离纯化和结构表征

目的 从平颏海蛇皮中提取分离糖胺聚糖(GAGs),并对其结构进行初步表征。方法 对海蛇皮进行脱脂处理后,采用木瓜蛋白酶和胰蛋白酶联合酶解提取粗多糖,采用氯代十六烷基吡啶(CPC)沉淀和Q-Sepharose Fast Flow离子交换树脂对粗多糖进行分离纯化。运用醋酸纤维素薄膜电泳分析其GAGs种类,采用1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生高效液相色谱(HPLC)法分析其单糖组成,利用硫酸软骨素酶降解结合质谱和强阴离子交换色谱(SAX-HPLC)法分析其2糖组成。结果 获得了2种GAGs纯化组分,并对其中1种含量较高的纯化组分(HSAP-2)进行了初步结构表征。HSAP-2中含有4种2糖,主要为单硫酸化2糖(4S和6S)和少量2硫酸化2糖(46S)、非硫酸化2糖(0S);单糖组成中含有葡萄糖醛酸(GlcA)和乙酰氨基半乳糖(GalNAc);是1种高度杂合的新型硫酸皮肤素(DS)。结论 从平颏海蛇皮中分离纯化获得了1种结构新颖的DS,为平颏海蛇多糖结构与生物活性的深入研究提供了基础。     

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.     

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.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

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.