1株链霉菌产胞外多糖ZS-11的结构表征及抗氧化活性研究

目的 对来源于南海深海海泥链霉菌Streptomyces pratensis OUCMDZ-3159所产胞外多糖的结构和抗氧活性进行研究。方法 利用醇沉法和柱色谱法对菌株所产胞外多糖进行分离纯化,利用多种仪器分析方法,包括PMP柱前衍生高效液相色谱法、红外光谱法和气相质谱联用法等分析了多糖的化学组成和结构,通过测定DPPH自由基清除活性、超氧阴离子自由基清除活性、羟基自由基清除活性和还原能力,对多糖的抗氧化活性进行评价。 结果 从链霉菌Streptomyces pratensis OUCMDZ-3159发酵液中得到了1种分子量为25.0 kDa的多糖组分ZS-11,它是由甘露糖和半乳糖以14.5:1的比例构成;糖链中包含(1→)-Manp,(1→2)-Manp,(1→3)-Manp,(1→6)-Manp,(1→2,3)-Galf和(1→2,6)-Manp连接方式;多糖ZS-11具有良好的抗氧化活性,在测定的4种活性指标中,清除DPPH自由基的能力最强。结论 首次从深海海泥放线菌Streptomyces pratensis OUCMDZ-3159中分离得到抗氧化活性显著的胞外多糖ZS-11,它是1种结构新颖的半乳甘露聚糖。     

红树林根泥真菌Aspergillus versicolor sp.PJX-9胞外多糖结构特征及抗氧化活性研究

目的对来源于红树林根泥真菌Aspergillus versicolor sp.PJX-9胞外多糖进行结构和抗氧化活性的研究。方法利用乙醇沉淀法、强阴离子交换色谱和凝胶渗透色谱对菌株发酵液中的胞外多糖进行分离纯化;通过高效凝胶渗透色谱(HPGPC)、PMP柱前衍生高效液相色谱(HPLC)、红外光谱(IR)及气质联用色谱(GC-MS)等方法,研究胞外多糖的化学组成和结构特征;通过测定DPPH、超氧阴离子和羟基自由基清除率,研究胞外多糖的抗氧化活性。结果从发酵液中分离得到的多糖组分Pw1-1的分子量为12.3kDa,其主要由甘露糖组成,少量葡萄糖和半乳糖;Pw1-1糖链中主要为(1→2)-Manp,还有少量(1→6)-Manp、(1→6)-Glcp和(1→2,6)-Manp及末端Manp和Gal f;Pw1-1具有良好的体外抗氧化活性,随着浓度的增加清除能力亦增强,对DPPH、超氧阴离子和羟基自由基清除的EC50分别为3.39、1.50和1.72mg/mL。结论首次从红树林根泥真菌Aspergillus versicolor sp.PJX-9中分离得到胞外多糖Pw1-1,它是1种具有良好体外抗氧化活性的结构新颖的杂多糖。     

红树林根泥放线菌Saccharopolyspora sp.胞外多糖的结构研究

目的 对源自红树林根泥放线菌Saccharopolyspora sp.的胞外多糖进行分离和结构研究。方法 通过乙醇沉淀、Q Sepharose Fast Flow阴离子交换层析柱和Sephacryl S-100凝胶层析柱对菌株发酵液中的胞外多糖进行分离纯化;采用HPGPC和PMP柱前衍生HPLC对多糖的纯度、分子量和单糖组成进行测定;通过IR、甲基化分析和NMR波谱对多糖的结构进行表征。结果 从放线菌Saccharopolyspora sp. 发酵液中分离得到两种多糖SSW1-1和SSW2-1,在HPGPC上均呈单一对称峰,分子量分别为17.0 kDa和12.7 kDa;SSW1-1和SSW2-1具有相似的单糖组成,主要由甘露糖组成;胞外多糖SSW1-1是以(1→2)-Manp和(1→6-Manp为主链的甘露聚糖,在(1→2)-Manp的C6位存在末端Manp、(1→3)-Manp和(1→2)-Manp的分支。结论 首次从红树林根泥放线菌Saccharopolyspora sp.发酵液中分离得到胞外多糖SSW1-1和SSW2-1,它们具有不同化学特征,SSW1-1是一种结构新颖的高分支的甘露聚糖。     

海洋真菌Cladosporium Sphaerospermum胞外多糖CS4-1结构特征和抗氧化活性

目的 对海洋真菌Cladosporium Sphaerospermum产生的胞外多糖CS4-1结构特征和抗氧化活性进行研究。方法 利用乙醇沉淀法、强阴离子交换色谱和凝胶渗透色谱对菌株所产胞外多糖进行分离纯化,运用PMP柱前衍生高效液相色谱法、高效凝胶渗透色谱法、气质联用色谱和化学方法分析多糖的结构特征,通过测定DPPH自由基、羟基自由基、ABTS自由基和超氧阴离子自由基清除活性以及还原能力评价多糖的抗氧化活性。结果 从海洋真菌Cladosporium Sphaerospermum发酵液中分离纯化得到胞外多糖CS4-1,其分子量为21.49 kDa;CS4-1含有甘露糖和半乳糖;糖链主要由Manp-(1→、→2)-Galp-(1→和→6)-Manp-(1→构成;CS4-1具有较好的抗氧化活性,在测定的5种活性指标中,清除超氧阴离子自由基的能力最强。结论 首次从海洋真菌Cladosporium Sphaerospermum分离得到抗氧化活性较好的多糖CS4-1,它是结构新颖的胞外多糖。     

北极海洋真菌Aspergillus jensenii胞外多糖的结构及抗氧化活性研究

目的 对北极海洋真菌Aspergillus jensenii胞外多糖的结构及抗氧化活性进行研究。方法 采用醇沉法提取、强阴离子交换色谱和凝胶渗透色谱对胞外多糖进行分离纯化;运用PMP柱前衍生高效液相色谱、高效凝胶渗透色谱、气相色谱-质谱和核磁共振波谱对多糖结构进行分析;通过测定ABTS自由基、DPPH自由基、羟基自由基和超氧阴离子自由基的清除能力评价多糖抗氧化活性。结果 分离得到1种多糖AJ1-1,其主要由甘露糖和少量半乳糖组成,糖链是以→2)-α-D-Manp-(1→和→6)-α-D-Manp-(1→为主,分支位于→2)-α-D-Manp-(1→的C-6位和→6)-α-D-Manp-(1→的C-2位,支链由Galf和Manp组成;AJ1-1具有较强的清除自由基能力（特别是对ABTS自由基、DPPH自由基和羟基自由基）。结论 首次从北极海洋真菌Aspergillus jensenii发酵液中分离得到含有呋喃型半乳糖分支的新颖半乳甘露聚糖,其是1种潜在的抗氧化多糖。     

南极海洋丝状真菌Lecanicillium kalimantanense HDN13-339 产生的胞外多糖结构表征及抗氧化活性研究D

目的 对来源于南极海洋丝状真菌Lecanicillium kalimantanense HDN13-339产生的胞外多糖的结构和抗氧化活性进行研究。方法 利用乙醇沉淀法、强阴离子交换色谱柱和凝胶渗透色谱柱对菌株所产胞外多糖进行分离纯化;通过PMP柱前衍生高效液相色谱法、红外光谱、气质联用色谱和核磁共振波谱对多糖的结构进行表征;通过测定DPPH自由基、超氧阴离子自由基、羟基自由基、ABTS自由基清除活性及Fe2+螯合能力研究胞外多糖的抗氧化活性。结果 从南极海洋丝状真菌Lecanicillium kalimantanense HDN13-339发酵产物中分离得到多糖HDN-51,其分子量为16.3 kDa,主要由甘露糖和半乳糖构成,糖链是由(1→)-Galf、(1→2)-Manp、(1→5)-Galf、(1→6)-Manp、(1→6)-Galf和(1→2,6)-Manp组成,HDN-51具有良好的抗氧化活性,特别是羟基自由基清除能力。结论　首次从南极海洋丝状真菌Lecanicillium kalimantanense HDN13-339中分离得到一种结构新颖的半乳甘露聚糖HDN-51,其具有一定的抗氧化活性。     

芙蓉菊多糖体外抗氧化活性研究

目的研究芙蓉菊多糖的体外抗氧化活性。方法采用1,1-二苯基苦基苯肼(DPPH)自由基、还原力、超氧阴离子、羟自由基4种体外抗氧化模型研究芙蓉菊多糖的抗氧化活性,用维生素C作对照。结果芙蓉菊粗多糖对DPPH自由基、还原力、超氧阴离子、羟自由基均有明显的清除能力,其中DPPH、超氧阴离子、羟自由基的EC50值分别为0.273、0.669、0.594mg/mL,对羟自由基清除能力强于维生素C。芙蓉菊多糖对自由基清除率与其质量浓度存在着明显的量效关系。结论芙蓉菊多糖具有良好的体外抗氧化活性,作为天然抗氧化剂和自由基清除剂有进一步研究的价值。     

5,7,4’-三羟基异黄酮基-8-对偶氮苯磺酸的合成及其抗氧化活性研究

目的合成未见文献报道的化合物5,7,4’-三羟基异黄酮基-8-对偶氮苯磺酸,并探讨其抗氧化活性。方法采用IR、1H-NMR、元素分析对其结构进行表征。利用荧光光谱法研究目标物对羟基自由基的清除活性,采用紫外光谱法研究目标物对超氧阴离子自由基和1,1-二苯基-2-苦肼基自由基(DPPH·)的清除活性。结果与结论目标化合物对1,1-二苯基-2-苦肼基自由基、羟基自由基和超氧阴离子自由基都有良好的清除活性,而且对羟基自由基的清除活性远高于对超氧阴离子自由基和1,1-二苯基-2-苦肼基自由基的清除活性。     

老龙皮多糖及水提物体外抗氧化活性比较

摘 要 目的：比较老龙皮水提物及老龙皮多糖的体外抗氧化活性。方法: 在体外化学模拟的条件下,采用比色法测定并比较老龙皮多糖及老龙皮水提物对Fe3+的还原能力,对羟基自由基、DPPH自由基、超氧阴离子自由基的清除能力以及对脂质过氧化的影响。结果: 老龙皮多糖及水提物能还原Fe3+,清除DPPH自由基及抗脂质过氧化反应,且老龙皮多糖优于水提物(P<0.05);同时两者还具有清除羟基自由基及超氧阴离子的作用,老龙皮多糖优于水提物,两者差异无统计学意义(P>0.05)。结论: 老龙皮多糖以及水提物具有一定的体外抗氧化活性,且老龙皮多糖的抗氧化活性优于老龙皮水提物,老龙皮多糖为老龙皮主要活性物质。     

松花粉抗氧化活性与主要成分的关联分析

目的:研究松花粉的抗氧化活性及其主要有效部位.方法:采用紫外分光光度法测定不同来源松花粉清除DPPH和羟基自由基的能力,及其总黄酮、总甾醇和总多糖的含量,并进行多元相关分析.结果:松花粉提取液对DPPH与羟基自由基均有清除作用,且都呈明显的量效关系;松花粉与破壁松花粉清除DPPH的平均IC50分别为14.86 g·L-1、12.95 g·L-1,清除羟基自由基的平均IC50分别为20.31 g·L-1、3.45 g·L-1;松花粉总黄酮、总甾醇的含量与清除DPPH自由基、羟基自由基的IC50呈负相关,并以总黄酮的相关性最为突出,而总多糖的含量则与其关联性不显著.结论:松花粉具有一定的抗氧化活性,其有效部位为黄酮和甾醇;松花粉破壁能有效提高其清除自由基的能力及总黄酮、总甾醇的含量.     

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.     

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.