含有芳基脲结构的4H-吡喃类化合物的设计、合成及抗肿瘤活性研究

目的 设计并合成一系列含有芳基脲结构的4H-吡喃类化合物，评价该类化合物的体外抗肿瘤活性。方法 以间硝基苯甲醛、丙二腈和丙酮二羧酸二甲酯为原料，通过“一锅法”合成含有硝基的吡喃中间体，该中间体的硝基经铁粉还原为氨基，再与取代异氰酸苯酯反应得到一系列目标化合物。以人大细胞肺癌细胞H460、人肺癌细胞A549和人结肠癌细胞HT-29 3种肿瘤细胞为测试细胞株，采用MTT法评价了目标化合物的抗肿瘤活性。结果 合成了11个含有芳基脲结构的4H-吡喃类化合物。体外抗肿瘤活性试验表明，11个化合物对3种肿瘤细胞株均具有很好的抑制活性。其中化合物7c活性突出，对H460和A549细胞的IC₅₀值分别为0.82，0.98 μmol·L^-1, 优于阳性对照药索拉非尼(IC₅₀=3.20， 2.83 μmol·L^-1)。结论 含有芳基脲结构的4H-吡喃类化合物具有很好的抗肿瘤活性，可作为抗肿瘤化合物的结构骨架进一步研究。     

13-酰胺基取代苦参碱衍生物的合成及抗肿瘤活性研究

目的 合成13-酰胺基取代苦参碱衍生物及研究该类化合物的体外抗肿瘤活性。方法 以槐果碱为原料,通过迈克尔加成（Michael addition）,叠氮还原酰化反应,制得系列13-位酰胺取代的衍生物,所有化合物结构均经¹H NMR等谱确证;选取人肝癌细胞（BEL-7404）和小鼠黑色素瘤细胞（K111）对所合成的目标化合物进行体外抗肿瘤药理活性筛选。结果 设计合成了9个新化合物,大多数化合物对两株肿瘤细胞都具有较强的抑制活性。结论 化合物4b和4e对人肝癌细胞（BEL-7404）有较强的抑制活性。     

虎杖苷及其衍生物抑制SGLT2降血糖活性研究

目的 揭示虎杖苷及其衍生物抑制钠-葡萄糖协同转运体2（sodium-glucose cotransporter 2,SGLT2）活性的构效关系。方法 以虎杖苷为起始物,经S_N2取代反应、催化氢化获得5个衍生物,以¹H-NMR和HR-ESI-MS进行结构表征。采用荧光标记的1-脱氧葡萄糖{1-[N-（7-nitrobenz-2-oxa-1,3-diazol-4-yl）amino]-1-deoxy-D-glucose,1-NBDG}作为底物对虎杖苷及其衍生物进行体外抑制SGLT2活性测试,对衍生物1b进行体内活性测试,大鼠口服糖耐量实验及促尿糖实验。结果 获得5个虎杖苷衍生物,¹H-NMR和HR-ESI-MS表征结构正确,体外实验显示虎杖苷及其衍生物能较好地抑制SGLT2活性,且化合物1b在10^-5 mol·L^-1时对SGLT2的抑制率达98.6%,但是大鼠体内实验显示1b在120 mg·kg^-1时抑糖率只有11%,尿糖量只有122 mg每200 g,其活性远远低于阳性对照药达格列净。结论 虎杖苷及其衍生物作为O-芳基糖苷化合物具有较弱的抑制SGLT2降血糖活性,其分子结构对后续设计新的C-芳基糖苷SGLT2抑制剂具有一定的指导意义。     

双分子γ-咔啉衍生物的合成及其对胆碱酯酶的抑制活性研究

目的 合成双分子γ-咔啉衍生物并研究其抑制乙酰胆碱酯酶的活性。方法 以N-乙酰基-3-溴-4-哌啶酮和苯肼为原料,经Fischer法一步合成关键中间体γ-咔啉,γ-咔啉在NaH作用下与二溴代物发生亲核取代反应生成双分子N₅-γ-咔啉系列衍生物,后者进一步在丙酮中经碘甲烷甲基化得到相应的季铵盐。用改良的Ellman法测定化合物的乙酰胆碱酯酶抑制活性。结果 合成了7个新的双分子γ-咔啉衍生物,其化学结构经IR、¹H-NMR、¹³C-NMR、ESI-MS确证。药理实验研究结果表明,所有目标化合物对乙酰胆碱酯酶均具有一定的抑制活性,化合物4g显示出与阳性对照多奈哌齐较为接近的抑制活性。结论 双分子γ-咔啉衍生物对乙酰胆碱酯酶具有抑制活性,连接链的长度对活性有影响,链长为8个碳原子时活性最佳,结构中的叔氮季铵化有利于提高活性。     

新型二芳基三嗪类抗锥体虫病化合物的三维定量构效关系研究

目的 建立具有预测能力的新型二芳基三嗪类抗锥体虫病化合物三维定量构效关系（3D-QSAR）模型。方法 通过对具有抗锥体虫活性的二芳基三嗪类化合物库进行结构分析,利用比较分子场分析法（CoMFA）和比较分子相似性指数分析法（CoMSIA）,建立3D-QSAR模型。结果 模型具有较高q²（q_CoMFA²=0.697,q_CoMSIA²=0.561）和r²（r_CoMFA²=0.998,r_CoMSIA²=0.966）值,表明2组模型具有较高的拟和能力及预测能力。结论 建立的CoMFA和CoMSIA模型均具有良好的预测能力,为设计更高活性的新型二芳基三嗪类抗锥体虫病化合物提供了理论依据和研究方向。     

3-芳基-5-三氮唑基-噁二唑衍生物HIF-1抑制剂的设计、合成与构效关系研究

目的 设计、合成3-芳基-5-三氮唑基-噁二唑类缺氧诱导因子-1(hypoxia-inducible factor 1，HIF-1)抑制剂。方法 以化合物8为先导，将吡唑基替换为1,2,3-三氮唑基，并对噁二唑和苯环取代基等进行改造，获得全新的3-芳基-5-三氮唑基-噁二唑衍生物。结果 所合成的大部分化合物均显示出较优的HIF-1抑制活性，化合物10n活性最强，IC₅₀值为0.59 μmol·L^-1，其作用机制是抑制HIF-1α蛋白表达，且能显著抑制SKOV3细胞的侵袭和迁移。结论 设计、合成的3-芳基-5-三氮唑基-噁二唑类衍生物是全新的HIF-1抑制剂，显示出抑制肿瘤迁移的效应。     

苯氧基磷酰氮芥取代的槐定碱衍生物的合成及其抗肿瘤活性研究

目的 设计合成苯氧基磷酰氮芥取代的槐定碱衍生物,并对其进行体外抗肿瘤活性研究。方法 以槐定碱为起始原料,经开环、酯化、磷酰化等反应合成目标化合物2a ～2e ,采用MTT法测定其对S180、H22、K562、MCF-7、SMMC-7721、LoVo肿瘤细胞的抑制活性。结果 设计并合成了5个目标化合物,其结构经¹H-NMR和ESI-MS确证。体外细胞测试结果显示所有化合物对S180和H22细胞株活性较强,且对正常细胞L929毒性小,部分化合物活性高于阳性对照药多柔比星。结论 目标化合物具有较强的抗肿瘤活性,化合物2b 为有潜力的候选化合物。     

苄基膦酸二乙酯乙酰胺类熊果酸衍生物的合成及其体外抗肝癌活性研究

目的 考察新型熊果酸衍生物的体外抗肝癌活性及其作用机制。方法 依据"Topliss决策法"将熊果酸与不同取代的苄基膦酸二乙酯片段通过取代反应得到目标化合物,并采用MTT法考察其体外抗肝癌活性;通过分子对接试验分析化合物可能的作用靶点并通过Western blotting试验加以验证。结果 目标化合物4a~4e的化学结构经过¹H-NMR﹑ ¹³C-NMR以及HRMS的联合确证;化合物4b及4e对BEL-7402及HepG2 2种肝癌细胞株的抑制活性优于熊果酸及阳性对照药5-氟尿嘧啶,同时对正常肝细胞L02的毒性显著降低;化合物4e呈浓度依赖性下调p-AKT蛋白的表达。结论 化合物4e的体外抗肝癌活性最为理想(针对HepG2的IC₅₀值为2.69 μmol·L^-1),可作为AKT蛋白抑制剂进行深入研究。     

氨基噻唑(噁唑)类化合物的合成及抗K562细胞活性研究

目的 设计、合成一系氨基噻唑（噁唑）类似物,并测试新衍生物对人类慢性粒细胞白血病细胞系K562的体外抑制作用。方法 以dasatinib为先导化合物设计新衍生物,通过亲核取代和关环缩合得到目标化合物,其结构通过¹H-NMR、¹³C-NMR、IR和MS测定。结果 发现5个目标化合物抑制活性高于对照药伊马替尼。4个化合物抗K562细胞活性高于dasatinib。结论 保持药效基团不变,用五元噻唑环取代芳香苯环,活性能得以改善。     

紫罗兰酮生物碱异噁唑衍生物的合成及其抗肿瘤转移活性研究

目的 设计并合成紫罗兰酮生物碱异噁唑类衍生物,结合活性筛选,发现具有活性的新型紫罗兰酮生物碱衍生物。方法 制备（R）-紫罗兰酮,在此基础上经过11步有机合成反应制备紫罗兰酮生物碱异噁唑衍生物。目标衍生物经核磁共振波谱和高分辨质谱表征其化学结构。通过乳腺癌细胞趋化迁移实验筛选衍生物的抗肿瘤转移活性。结果 共制备8个目标衍生物,经抗肿瘤转移活性筛选发现,化合物12c活性同Ion-31a相当,强于阳性对照化合物PI3K抑制剂LY294002。结论 所有目标衍生物均为新化合物,其中苯甲腈取代异噁唑化合物12c具有显著抗肿瘤转移活性。     

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.