新型槲皮素衍生物的合成及其抗肿瘤活性研究

目的 设计并合成以槲皮素为母核,研究3′-位羟基引入芳香丙烯基槲皮素衍生物的体外抗肿瘤活性。方法 以槲皮素为原料,用不同取代的芳香丙烯酸与其3′-位羟基缩合成酯,得目标槲皮素衍生物,并通过核磁共振波谱仪(¹H-NMR)进行结构表征,同时用噻唑蓝比色法(MTT法)测试目标化合物对不同肿瘤细胞的抗肿瘤活性。结果 通过抗肿瘤活性测试显示,所合成的目标化合物对人结肠癌细胞和乳腺癌细胞表现出了较好的抗肿瘤活性,均达到了微摩尔级,其中化合物5C₁和5C₆对乳腺癌肿瘤细胞的细胞毒达到了10微摩尔级,半抑制浓度(IC₅₀)分别为10.59 μmol/L和10.31 μmol/L。结论 该系列槲皮素衍生物的合成为后续槲皮素衍生物的合成研究和获得具有潜在抗肿瘤活性的先导化合物奠定了基础。     

葡萄糖苯丙苷类化合物的合成及其抗肿瘤活性

目的设计合成葡萄糖苯丙苷衍生物，并寻求具有抗肿瘤活性的新化合物。方法四乙酰基溴代葡萄糖与醇经过成苷、脱保护、与苯甲醛缩合3步反应得到目标化合物。以A431（人表皮鳞癌细胞）、A549（人肺腺癌细胞）、7721（人肝癌细胞）3种肿瘤细胞为测试细胞株，采用M1vr法评价了目标化合物的抗肿瘤活性。结果与结论合成了19个糖苷衍生物，其结构均经。H—NMR确证。体外抗肿瘤活性实验表明，4，6-O-亚苄基β－D－吡喃葡萄糖－3－（4－甲氧基苯基）丙苷（1j）显示出较好的抗肿瘤活性。     

马蹄金素衍生物的合成及其抗HBV活性研究

目的对马蹄金素[N-(N-苯甲酰基-L-苯丙氨酰基)-O-乙酰基-L-苯丙氨醇,MTS]进行结构修饰,以期寻找到抗乙肝病毒(HBV)活性更强、毒性更低的马蹄金素衍生物。方法以马蹄金素为先导化合物进行结构优化,合成一系列不同取代基团的马蹄金素衍生物并对其进行抗HBV活性测试。结果合成了马蹄金素衍生物共计9个,经体外活性筛选结果显示有4个衍生物具有抗HBV活性,4a(IC50:24.20μmol·L-1,SI:3.69)、5f(IC50:252.60μmol·L-1,SI:>3.96)、5g(IC50:0.82μmol·L-1,SI:52.57)、5h(IC50:1.44μmol·L-1,SI:59.97)。结论化合物5g和5h显示较强的抗HBV活性,选择指数较高,具有进一步研究开发的价值。     

箭叶淫羊藿中化学成分及其体外抗肿瘤活性研究

目的 分离箭叶淫羊藿中的化学成分并对8-异戊烯基黄酮类化合物进行体外抗肿瘤活性筛选.方法 采用硅胶柱色谱、凝胶柱色谱和HPLC制备色谱方法分离纯化,根据理化性质和波谱分析方法鉴定其结构,利用MTT法对分离得到的异戊烯基黄酮类化合物进行体外抗肿瘤活性筛选.结果 分离得到7个黄酮类化合物,分别鉴定为淫羊藿苷(1)、淫羊藿素(2)、宝藿苷Ⅰ(3)、去甲淫羊藿素(4)、苜蓿素(5)、淫羊藿次苷Ⅰ(6)和朝藿定C(7).体外抗肿瘤结果表明,在0.5～1 00 μmol/L浓度,化合物2、3、4、6对人乳腺癌MDA-MB-231细胞增殖具有明显抑制作用,并随浓度的增加抑制作用更加明显,48 h的IC50分别为12.43、35.44、11.53、16.31 μmol/L,化合物1、7活性很弱.结论 化合物3、4为首次从箭叶淫羊藿植物分离得到,化合物3有望成为靶向抗乳腺癌的候选药物.     

菲并咪唑衍生物的体外抗肿瘤活性及其对斑马鱼胚胎发育的毒性效应研究

目的 设计合成菲并咪唑衍生物L271,并研究其外抗肿瘤活性,及其对斑马鱼胚胎发育的毒性效应.方法 以1,10-邻菲啰啉-5,6-二酮和2-甲基苯甲醛为原料,运用微波辅助合成技术制备了菲并咪唑衍生L271.采用噻唑蓝(MTT)比色法研究菲并咪唑衍生物L271对人宫颈癌细胞Hela和人肺腺癌细胞A549在体外生长的抑制作用.以斑马鱼为模型,研究L271对斑马鱼胚胎发育的形态、孵化率、死亡率和畸形率的影响,评价L271对斑马鱼胚胎发育的毒性效应.结果 经电喷雾质谱技术(ESI-MS)表征确证成功合成了目标化合物L271.新合成的菲并咪唑衍生物L271对人宫颈癌细胞Hela和人肺腺癌细胞A549均有增殖抑制作用,尤其对人宫颈癌细胞Hela的IC50值达到(8.38±0.09)μmol/L,与同等条件下吡柔比星的抗肿瘤活性相当[IC50=(6.97±0.07)μmol/L].与对照组相比,L271浓度≥15μmol/L暴露组能够引起斑马鱼出现尾鳍萎缩、脊柱弯曲、卵黄囊水肿和心包囊水肿等畸形现象;L271浓度≥30μmol/L可显著降低斑马鱼的孵化率和提高死亡率(P＜0.05);在48、72、96 hpf时,L271对斑马鱼胚胎半致死浓度LC5o分别是37.331μmol/L(95％CI:35.535-39.301)、34.911μmol/L(95％CI:33.213-36.729)、30.283μmol/L(95％CI:29.590-30.980);在L271浓度≥15μmol/L时,随着L271浓度的逐渐增加,各暴露组正常胚胎百分率渐下降,胚胎死亡率逐渐上升,而胚胎畸形率先升后降.结论 L271对人宫颈癌细胞Hela具有良好的抗肿瘤活性,且与吡柔比星的相当;L271浓度≤10μmol/L对斑马鱼胚胎发育无明显毒性效应.     

美法仑衍生物的合成及其抗肿瘤活性研究

目的以苦参碱和18α-甘草次酸作为载体对美法仑进行结构拼合,并对其体内外抗肿瘤活性进行研究。方法以槐果碱和美法仑为原料,经过加成、酰化反应合成了美法仑衍生物2;以18α-甘草次酸和美法仑为原料,经酯化和酰化反应合成了美法仑衍生物5,目标化合物的结构经元素分析、MS、1H-NMR确证,并采用MTT法对其进行体外抗肿瘤活性研究,对体外活性较为显著的化合物2进行小鼠体内试验。结果目标化合物2和5的合成总收率分别为21.3%、18.1%。目标化合物2的体外抗肿瘤活性明显高于化合物5、18α-甘草次酸、苦参碱和美法仑。体内活性试验中,目标化合物2给药剂量为6、9μmol/kg时对Hep A肿瘤的抑瘤率分别为52.00%、62.12%,而6μmol/kg美法仑的抑制率为39.93%,化合物2的抑瘤效果优于美法仑,尤以高剂量效果最为明显。结论化合物2表现出体外、体内较高的抗肿瘤活性,值得进一步研究。     

海鞘素简易结构类似物GJ7-1和GJ7-2的抗肿瘤活性及分子靶向研究

目的:研究依照特有DNA靶向性的抗肿瘤海洋天然产物海鞘素(Ecteinascidins,ETs)合成的简易结构类似物GJ7-1和GJ7-2的抗肿瘤活性及分子靶向。方法:MTT法检测0.012 5¹.6μmol/L的GJ7-1、GJ7-2作用72 h对10种体外培养的肿瘤细胞的增殖抑制作用;荧光结合竞争法测定0.011.6μmol/L的GJ7-1、GJ7-2作用72 h对10种体外培养的肿瘤细胞的增殖抑制作用;荧光结合竞争法测定0.01¹00μmol/L的GJ7-1、GJ7-2与DNA的结合情况;流式细胞仪检测0.01、0.1、1μmol/L的GJ7-1、GJ7-2对A549细胞周期(作用24、48 h)的影响;Hochest33342染色和AnnexinⅤ/PI双染检测0.01、0.1、1μmol/L的GJ7-1、GJ7-2对A549细胞凋亡(作用24、48、72 h)的影响。结果:GJ7-1和GJ7-2对10种肿瘤细胞均有增殖抑制作用,但无明显肿瘤类型选择性;浓度增加到100μmol/L时也与DNA无明显结合;仅1μmol/L的GJ7-1、GJ7-2对A549细胞周期有一定的影响,但均不能诱导其明显凋亡。结论:GJ7-1和GJ7-2虽有一定的抗肿瘤活性,但较ETs大幅降低,部分原因是其完全丧失了与DNA的结合活性。     

杨梅素糖苷衍生物的合成及其抗菌活性研究

摘要：目的 设计合成杨梅素类糖苷衍生物,并进行抗菌活性研究。方法 以天然产物杨梅苷为起始原料,经过保护基策略、糖苷化反应、酯化反应制备得到一系列新型半乳糖苷衍生物,对杨梅素类衍生物进行了抑菌活性研究。结果 以杨梅苷为原料,设计合成了14个杨梅素类衍生物,其中包含有8个未见文献报道的新型糖苷化合物,其结构经核磁、ESI-MS进行了确证。体外抗菌活性结果显示,8个杨梅素衍生物具有较杨梅素和杨梅苷更强的抗菌活性,其中,化合物9a-1~9a-4对金黄色葡萄球菌和表皮葡萄球菌的抗菌活性MIC值为1~8 μg/mL。结论 本研究首次以杨梅苷作为原料,设计了新的合成路线,并对合成中的关键反应条件进行了优化,构建了一条高效快捷的杨梅素衍生物的制备方法。化合物的初步活性结果显示,黄酮醇3位羟基半乳糖修饰可以显著提高杨梅素的抗菌活性,为杨梅素的进一步抗菌化合物的寻找提供了新的线索。     

薯蓣皂苷元衍生物的抗肿瘤活性研究

目的研究薯蓣皂苷元衍生物在体外的抗肿瘤活性。方法采用MTT法对人恶性黑色素瘤细胞A375、人肺腺癌细胞A549、人肝癌细胞HepG-2及人慢性髓原白血病细胞株K562进行体外抗肿瘤活性试验。结果薯蓣皂苷元衍生物对4个肿瘤细胞株A375、A549、K562、HepG-2具有不同程度的抗肿瘤活性。结论绝大部分薯蓣皂苷元衍生物对4个肿瘤细胞株有较好的抗肿瘤活性,IC50值都低于30μmol.L-1。化合物22对细胞株A375的IC50=4.48μmol.L-1,化合物9、10对细胞株K562的IC50分别为2.51、2.38μmol.L-1;显示其抗肿瘤活性与对照化合物1-(3β-薯蓣皂苷元)-3-苄基咪唑溴盐相当。     

沙蟾毒精酯类衍生物的合成和抗肿瘤活性研究

目的基于活性天然产物沙蟾毒精骨架设计3-酯类衍生物,并测试其抗肿瘤活性。方法通过缩合剂催化下将酸和沙蟾毒精进行酯化反应,得到3-酯类沙蟾毒精衍生物,采用Cell Titer法测试体外抗肿瘤活性。结果3-沙蟾毒精酯类衍生物对所有的肿瘤细胞株显示出优异的体外抗肿瘤活性,其IC50值均在1μmol/L以下。结论化合物2a活性最好,对3种肿瘤细胞株的IC50值为4.0~91.7 nmol/L,可作为抗肿瘤候选化合物进行进一步研究。     

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.