云雾绿茶多糖提取方法的优化及Sevage法除蛋白的工艺研究

目的研究云雾绿茶多糖提取方法的优化以及Sevage法除蛋白的最佳工艺。方法采用两因素优化提取工艺,正交设计优化除蛋白工艺。结果云雾绿茶多糖提取方法的优化中,温度和溶剂对实验结果有影响,最佳条件:溶剂为蒸馏水,温度为85℃。Sevage法除蛋白工艺中除蛋白次数和试剂添加量有显著影响,V_(氯仿):V_(正丁醇)影响较小,最佳工艺:V_(试剂添加量):V_(茶多糖溶液)=1/5,V_(氯仿):V_(正丁醇)=4:1,除蛋白时间为20min。结论优化了云雾绿茶多糖的提取和除蛋白的工艺,为下一步实验奠定了基础。     

人参花蕾中6个新的具氢过氧化物结构的达玛烷型三萜皂苷

人参花蕾曾被用作兴奋剂,从该部位分离出6个新的(1~6)和7个已知的(7~13)达玛烷型三萜皂苷。将干燥的人参花蕾以甲醇回流提取4次,共3h,回收溶剂得甲醇提取物,该提取物用醋酸乙酯-水(1∶1)分配,水相用正丁醇进一步提取。正丁醇溶部位减压浓缩后经硅胶柱色谱分离,氯仿-甲醇-水梯度     

南瓜多糖的提取与分离工艺的优化

目的 研究南瓜多糖的提取与分离工艺的优化。方法 采用正交实验L9(3^4)对南瓜多糖的水提取工艺进行优化设计，通过单因素实验确定南瓜多糖分离的最佳工艺．结果 南瓜多糖提取工艺各因素的最佳水平为A3B2C1D3(料液比1：3，在70℃下提取3次，每次4小时)。南瓜多糖提取工艺各因素中因素D(提取次数)和因素A(料液比)的差异对多糖得率有显著性影响，而因素B(提取时间)与因素C(提取温度)的差异无显著性影响。以乙醇沉淀多糖(终浓度70％)Sevag试剂去除游离蛋白(多糖溶液与Sevag试剂的体积比2t1，反复脱蛋白7次，每次30min)；H2O2溶液脱色(终浓度4％，50℃保温2h)能达到良好的效果。粗多糖得率为1．92％；总糖含量为79．3％。结论 本文建立的优化工艺可为南瓜多糖的分离制备提供参考．根据正交实验统计分析结果，为了省时节水节能，采用少量短时多次提取工艺(料液比1：2，在70℃下提取3次，每次3小时)较为合理。     

槐耳菌丝体多糖的分离和分析

由固体培养法得到的槐耳菌丝体,经沸水提取,氯仿-正丁醇除蛋白、乙醇沉淀,分离制备的多糖具有明显提高机体免疫功能的作用,组成分析表明槐耳多糖为蛋白结合多糖,组成单糖为L-岩藻糖、L-阿拉伯糖、D-木糖、D-甘露糖、D-葡萄糖、D-半乳糖。     

家兔肝脏中锌-金属硫蛋白提取工艺的优化

用正交试验法对硫酸锌诱导的兔肝锌-金属硫蛋白(Zn-MT)的提取工艺进行优选，以原子吸收法测得锌提取量和差示紫外分光光度法测得巯基活性为评价指标，选用L9(3^4)正交表进行正交实验。考察影响提取Zr-MT的四个因素分别为：pH值8．6的Tris-HCl缓冲溶液浓度、温度、用量和-20℃预冷乙醇-氯仿(1：0．08)混合液与缓冲溶液体积比。所得最佳方案为：每克兔肝加3ml 80℃，pH值8．6的0．05mol／L Tris-HCl缓冲溶液，匀浆，再按每克兔肝加2ml乙醇氯仿(1：0．08)混合液，摇匀，提取。最佳方案所得提取液经凝胶色谱法初步分离得Zn-MT收率约为4．2mg／g肝。     

正交试验优选铁皮石斛类原球茎多糖的提取纯化工艺

目的:优选铁皮石斛类原球茎多糖提取纯化工艺。方法:采用正交试验,以多糖含量为评价指标,以液固比、浸提时间、提取次数为考察因素优选提取工艺;以样品溶液与Sevage试剂体积比、氯仿与正丁醇的体积比、反应时间为考察因素优选纯化工艺。结果:多糖最佳提取纯化工艺为80℃热水浸提多糖,液固比为20倍,提取时间2h,提取次数3次,80%乙醇沉淀,样品溶液与Sevage试剂体积比为4∶1,氯仿与正丁醇的体积比为5∶2,反应时间为5min。结论:所建方法简便、可靠、重现性好,可供本品质量控制。     

超滤提取香菇多糖的研究

目的：探讨超滤提纯香菇多糖的可行性及工艺。方法：采用螺旋卷式超滤器对香菇多糖进行提取研究。结果：在此实验范围内,用微滤作预处理较离心法效果好,超滤温度为25℃,pH值接近浸提介质的pH,超滤压力为0．15～0．18MPa,制得香菇多糖的纯度为74．4％,回收率79.6％,是以D-葡聚糖为主的混和多糖。结论：超滤提纯香菇多糖是一种可行的方法。     

不同生长年限泰山四叶参中多糖的含量测定

目的:从栽培的不同生长年限的泰山四叶参中提取多糖并测定其含量。方法:四叶参粗粉经脱脂、醇提后用水提醇沉法提取粗多糖,氯仿-正丁醇(4∶1)脱蛋白,苯酚-硫酸法测定其含量。结果:2年、3年和4年生泰山四叶参中多糖的含量依次为8.82%、10.47%和11.32%;平均回收率为96.09%,RSD=1.25%(n=6)。结论:4年生泰山四叶参中多糖含量最高。本法简便、准确,可为确定泰山四叶参的合理采收时间奠定科学基础。     

咳尔康口服液中多糖脱蛋白方法研究

目的研究咳尔康口服液中多糖脱蛋白的方法。方法以糖保留率和蛋白去除率为指标,对氯化钙法、盐酸法、三氯乙酸法、Sevag法4种脱蛋白方法进行比较。结果通过正交试验确定了Sevag法的最佳条件为：样品：（氯仿-正丁醇）=3：1,氯仿：正丁醇=3：1,振荡30min,添加试剂2次。结论 Sevag法脱蛋白效果最好。     

香菇多糖构效关系、抗肿瘤作用机制及药代动力学研究进展

香菇多糖(lentinan, LNT)是从香菇子实体中提取纯化的最主要生物活性成分，主要为C6分支的β-(1→3)-D-吡喃葡聚糖主链结构。LNT具有显著的免疫调节及抑制肿瘤生长作用，广泛用于临床抗肿瘤辅助治疗，能有效改善肿瘤患者的生活质量。然而，由于其提取纯化工艺繁琐，构象信息和构效关系缺乏，直接抗肿瘤作用机制尚无定论，体内代谢过程不明确，极大限制了LNT的临床应用。该文主要对香菇多糖的提取方法、构效关系、抗肿瘤作用机制及药动学进行综述，以期为香菇多糖的临床合理应用提供参考。     

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.