2,5-二芳基-1,3-氧硫戊环化合物的合成及iNOS/PAF双重抑制活性的研究

目的寻找既能抑制iNOS又能拮抗PAF受体的化合物.方法以具有PAF受体拮抗活性的2,4-二芳基-1,3-二硫戊环为先导物,合成其生物电子等排体氧硫戊环化合物,并在其2位芳环上引入具有iNOS抑制活性的基团,测定目标化合物的iNOS抑制活性和PAF受体拮抗活性.结果合成了25个未见文献报道的目标物,其中9个化合物(I2～I7、I10、Ⅱ5、Ⅱ6)的iNOs抑制活性强于正在Ⅲ期临床的iNOS抑制剂氨基胍.PAF受体拮抗活性测试表明,I4活性高于阳性对照药ZH-2,I5活性与ZH-2相当,I 2、I6、I8、I10和Ⅱ5、Ⅱ6活性稍低于ZH-2.结论 I4、I5具有较高的iNOS/PAF双重抑制活性,值得进一步研究.     

木酚素二硫戊环类似物抑制γ-干扰素和脂多糖在巨噬细胞中诱生一氧化氮(英文)

目的:研究木酚素二硫戊环类似物及血小板活化因子(PAF)受体拮抗剂L-659,989对PAF-受体结合,对γ-干扰素和脂多糖诱导的一氧化氮(NO)生成,以及对iNOS mRNA表达的影响.方法:通过对兔血小板膜中~3H标记的PAF-受体竞争结合试验来研究对PAF-受体的拮抗作用;测定NO的氧化产物亚硝酸盐来定量NO的生成.用RNA印迹分析来研究对iNOS mRNA表达的影响.结果:二硫戊环类似物抑制NO的生成,减少iNOS mRNA的表达,拮抗~3HPAF受体.L-659,989对NO生成和iNOS mRNA表达没有影响.受试物的PAF受体拮抗活性和iNOS抑制活性之间无简单关联.结论:木酚素二硫戊环类似物是iNOS表达的新型调控剂,具有抑制iNOS,诱导和拮抗PAF受体的双重活性.     

2-正丁基-1,3-二氮杂螺[4,4]壬-1-烯-4-酮的合成

目的：合成2－正丁基－1，3－二氮杂螺[4,4]-壬－1－烯－4－酮。方法：以环戊酮合成的1－氨基环戊酸为起始原料。结果：1－氨基环戊酸经过酯化，与戊亚氨酸乙酯缩合得目标化合物。结论：该合成工艺有一定改进。     

N-芳甲酰基-N’-取代嘧啶基硫脲类 化合物的合成与初步活性研究

目的 合成N-芳甲酰基-N’-取代嘧啶基硫脲类化合物,并初步测试其对血管平滑肌细胞增殖的抑制活性。方法　以2-氨基-5-溴-4-取代嘧啶与芳甲酰基异硫氰酸酯反应,得到一系列N-芳甲酰基-N’-取代嘧啶基硫脲类化合物;采用MTT法测定目标化合物对血清诱导的血管平滑肌细胞增殖的抑制活性。结果与结论　合成的10个目标化合物,均未见文献报道,所有目标化合物结构经1H-NMR及MS确证;活性测试结果表明,化合物6b、6c、6g、6j 具有一定的血管平滑肌细胞增殖抑制活性。     

高圣草素-7-O-β-D-葡萄糖苷抑制血小板活化因子诱导血小板聚集的机理探讨(英文)

高圣草素-7-O-β-D-葡萄糖苷是从中草药槲寄生中提取分离的一种黄酮类化合物。已证实该化合物在体内外对血小板活化因子（PAF）诱导的人及兔血小板聚集有明显的抑制作用。本研究应用放射配体[3H]PAF与受体结合的抑制实验证实该化合物是在受体水平上阻断了PAF对血小板的活化作用。抑制呈剂量效应关系,化合物浓度的负对数与抑制率明显相关γ=0.985,P<0.05）。在浓度大于1×10~-5 mol·L~-1时,增加浓度,不能提高抑制率,提示抑制的饱和。抑制的IC50为8×10~-7 mol·L~-1。首次发现,高圣草素-7-O-β-D-葡萄糖苷通过阻断PAF受体而抑制PAF诱导的血小板聚集。     

4-苯基-2-氨基嘧啶类化合物的设计合成及其抗肿瘤活性

目的设计合成一系列4-苯基-2-氨基嘧啶类新型化合物,并测定其对前列腺癌细胞(PC-3)的生长抑制活性。方法以硝基苯乙酮为起始原料,通过嘧啶环合、酰胺缩合、硝基还原、氨基保护及脱保护反应合成目标化合物。采用MTT法测试化合物对前列腺癌PC-3细胞的生长抑制活性;采用均相时间分辨荧光法测定化合物对激酶AKT1的抑制活性。结果与结论合成了9个未见文献报道的4-苯基-2-氨基嘧啶类化合物,其结构经1H-NMR、MS谱确证。化合物9a-1、9a-3、9b-1(5μmol·L-1)对激酶AKT1的抑制率大于60%。     

4-((4-((2-取代苯氧基)乙基)-1-哌嗪)-甲基)-1,2-二氢喹啉-2-酮类化合物的合成及体外α-受体拮抗活性

目的研究DDPH类似物1,2-二氢喹啉-2-酮类化合物的合成及其体外α-受体拮抗活性。方法通过酰化、溴代、环合和取代反应等合成目的物;推测了异常中间体3-溴-4-溴甲基-1,2-二氢喹啉-2-酮(5)和3-溴-4-甲基-1,2-二氢喹啉-2-酮(6)的生成机理;测定目的物的体外α-受体拮抗活性。 结果设计、合成了12个新化合物II_1～6和IV_1～6,其中6个目的物1,2-二氢喹啉-2-酮类(IV_1～6)的结构经IR,¹HNMR,MS和HRMS确证;IV₃,IV₄和IV₆对兔主动脉环抑制作用较明显。结论化合物IV₃,IV₄和IV₆显示了一定的抑制活性,值得进一步研究。     

RGDS的抗血小板聚集及舒血管效应

血小板聚集是正常止血的要素,并依赖于膜糖蛋白Ⅱ_b/Ⅲ_a(GPⅡ_a/Ⅲ_a)复合物与血浆粘附糖蛋白(包括纤维蛋白原 von Willebrand 因子和 fibronectin)的相互作用。研究 GPⅡ_b/Ⅲ_a 受体与纤维蛋白结合确定了在介导其自身与 GP Ⅱ_b/Ⅲ_a 接触的纤维蛋白分子中存在两种不同的氨基酸序列。其中一种序列是 Arg-Gly-Asp(RGD),该序列不仅出现在纤维蛋白 Aα链中,也出现在 fibronectin 和 von Willebrand 因子中。为了阐明其生物学效应本文合成了RGDS,并进行了与抗栓有关的生物学评价。本研究提供的数据证实 RGDS 明显抑制 PAF或 ADP 诱发的血栓形成(对 PAF 诱导的血小板聚集抑制率为67%,RGDS 浓度为9.6×10~(-7)mol/L;对 ADP 诱导的血小板聚集抑制率为87%,RGDS 浓度为9.6×10~(-7)mol/L)。该观察与 RGDS 延缓血栓形成的发现相符。虽然 RGDS 对 ADP 比对 PAF 更敏感但它对 PAF 的抑制仍十分明显这些结果均属首次报道。本研究进一步揭示了 RGDS 有舒血管作用,而且它对大鼠主动脉肌条的舒张作用不可忽视(与对照相比1×10~(-5)mol/L 的 RGDS 在 NE 处理的鼠动脉肌条上的舒张幅度为8.08±5.0%,P<0.05)。对组织内 cGMP 的累积水平(与对照相比1±10~(-5)mol/L 的RGDS 引起 cGMP 水平增高4.68±1.9pmol/mg,P<0.05)研究结果表明,提高体内 cGMP 的水平可能是 RGDS 发挥生物学作用的机制之一。RGDS 的舒血管和抗血小板聚集两种作用均可作为设计与合成新型抗栓剂的实验依据。     

芳氧基-芳酰基哌嗪取代乙胺丙醇类α,β受体双阻滞剂的合成

目的 设计合成具有α、β受体双阻滞作用的系列化合物，并进行活性的初步筛选。方法 运用系列化电子等排原理，设计合成了系列1-芳氧基—3—[2-(4—芳酰基哌嗪)乙氨基]—2—丙醇衍生物，并经MS、^1H—NMR、IR确证其结构。结果 与结论合成了15个目标化合物，其中12个为新化合物，初步活性测定结果显示：所合成的化合物均具有α、β多受体双阻滞作用。     

N-[4-(苯并咪唑-2-硫基)苯基]-N'-烷基胍类衍生物的合成和生物活性

为了寻找对诱生型一氧化氮合酶(inducible nitric oxide synthase，iNOS)有抑制活性的新型化合物，设计合成了一系列N-［4-(苯并咪唑-2-硫基)苯基］-N′-烷基胍类衍生物(I₁～I₁₂)。以2-巯基苯并咪唑(1)为原料，经缩合和还原得到2-(4-氨基苯硫基)苯并咪唑(3)，再与异硫氰酸苯甲酰酯反应得双取代硫脲(4)，4经水解和S-烷基化得到关键中间体S-乙基-n-［4-(苯并咪唑-2-硫基)苯基］异硫脲氢碘酸盐(6)，6与伯胺或仲胺反应得目标化合物I₁～I₁₂。这些化合物的结构经IR，¹H NMR，MS和元素分析得到确证。初步的iNOS抑制活性测定结果显示，3个化合物(I₁，I₈和I₁₀)的活性强于阳性对照药氨基胍，其中化合物I₁的活性是氨基胍的5.5倍。     

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.     

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.     

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.