单缺位Keggin型钨硅杂多酸盐结构、反应性和抗肿瘤活性

研究一缺位聚阴离子,SiW11O39^8-结构、反应性和抗肿瘤活性。用x-射线衍射、元素分析、UV光谱,结构表征研究SiW11O39^8-骨架的结构特点和与p2族金属离子Sn^4-和过渡金属离子Co^2＋、Cr^3＋的反应性。重点用小鼠移植性肿瘤S180、P388研究体内抗肿瘤作用。杂多酸盐K8[SiW11O39].13H2O（Ⅰ）为一缺位Keggin α-型结构;它在pH=4～4.5和一定温度下反应得到,六方晶系的饱和Keggin α-型三元杂多化合物α-K5SiSnW11O39（OH）.17H2O（Ⅱ）和α-K8[SiCrW11O39H2O].10H2O（Ⅳ）及四方晶系的饱和Keggin α-型化合物α-K6SiCoW11O39.14H2O（Ⅲ）。化合物（Ⅰ）对S180、P388有较强的抑瘤效果。化合物（Ⅰ）对S180抑瘤率峰值≥42.38%,荷瘤小鼠最大生命延长率≥36.94%;对P388生命延长率为37.5%。     

[CuI(2,2''-bipy)(4,4''-bipy)0.5]2[CuI(4,4''-bipy)]2[SiW12O40]的合成与晶体结构

文中利用水热技术,成功合成了有机-无机杂化材料:[CuI(2,2'-bipy)(4,4'-bipy)0.5]2[CuI(4,4'-bipy)]2[SiW12O40],并应用红外光谱、元素分析、单晶X-射线衍射等进行了表征.结果表明,标题化合物的基奉结构单元是由一个双支撑的经典的Keggin型[SiW12O40]4-多氧阴离子形成-维Z字形链,该一维链又通过|CuI(4,4'-bipy)|nn+单元形成三维骨架.该晶体属于三斜晶系:P-1空间群;晶胞参数a=10.930(2)A.b=13.550(3)A.c=13.729(3)A,α=109.80(3)°,β=103.46(3)°,γ=98.69(3)°,V=1800.83(60)A3,Z=2,R1=0.0697,ωR2=0.1576.     

Keggin型和Dawson型杂多酸的制备及其催化氧化性能比较研究

合成了10种杂多酸型催化剂,用红外（IR）等手段对其进行结构物相分析,一并将其应用于蒽氧化制蒽醌的反应,在同样的条件下比较了Dawson结构和Keggin结构系列杂多化合物的氧化催化性能,得到了一些有意义的结果。     

(MePh_3P)_n-Keggin结构多金属氧酸盐纳米材料的合成、表征及其催化性能

以Keggin结构杂多酸为原料,利用高效、环保的室温固相化学反应一步合成了有机-无机杂化多金属氧酸盐纳米材料(MePh_3P)_n-Keggin。通过TG-DSC、IR以及SEM对产物进行了表征。结果表明,杂多阴离子在有机-无机杂化结构中保持了其稳定的Keggin结构,SEM照片显示(MePh_3P)_3-PMo_(12)纳米颗粒粒径较均一、表面粗糙不平;而(MePh_3P)_4-SiW_(12)则是表面光滑的多面体结构。正丁醇的酯化催化实验表明,(MePh_3P)_3-PMo_(12)纳米颗粒的催化活性大于(MePh_3P)_4-SiW_(12)纳米多面体。从杂多酸的氧化能力和纳米结构的差异方面讨论了它们对催化性能的影响,为纳米功能材料提供了一条简单有效、绿色环保的合成路线,丰富了纳米材料的合成技术。     

HIV-1整合酶肽抑制剂的研究进展

目前治疗人类免疫缺陷Ⅰ型病毒(HIV-1)感染的方法主要是针对靶点逆转录酶(RT)和整合酶(IN)联合用药.联合治疗方法有很多的临床优势,但高抗药性的出现,迫切需要能研究抗HIV-1新药物.新药物需要能与病毒复制周期另外的一些步骤中关键蛋白发生作用,比如在宿主基因组中整合病毒DNA.基于这些考虑,目前国际上研究肽化合物药物成为一个热点,一些肽化合物在体内及体外实验中,对RT和IN均产生了很大的抑制活性.本文综述了随着最近一些新技术的出现而挑选出的对目标蛋白有强结合力的肽.这些新技术的出现为研究抗HIV-1药物提供了一种新方法.     

二氧化钛负载磷钨钒杂多酸的制备及其催化氧化脱硫性能研究

采用酸化-乙醚萃取法制备了Keggin结构的磷钨钒杂多酸,并分别采用浸渍法、溶胶-凝胶法制备了二氧化钛负载型杂多酸催化剂,采用紫外和红外光谱对催化剂进行表征.以H2 O2为氧化剂,以二苯并噻吩(DBT)的正辛烷溶液为模型柴油,对其氧化脱硫反应进行了研究,考察了催化剂对模拟油品中二苯并噻吩(DBT)的氧化脱硫反应性能研究,考察了不同制备方法、不同负载量对催化剂脱硫效率的影响.结果表明,溶胶凝胶法制备的负载型催化剂明显优于浸渍法制备的催化剂,在反应温度50℃,反应时间为4小时,n(H2 O2)/n(s)=4:1的优化条件下,DBT转化率达到89％.催化剂通过简单过滤法可分离回收,重复使用5次后DBT转化率为83％.     

嘧啶硫酮-姜黄素杂合体的合成及抗氧化活性研究

本文由姜黄素和硫脲两组分合成了一种新型的嘧啶硫酮化合物6-(4-羟基-3-甲氧基苯)-4-((1Z,3E)-羟基-4-(4-羟基-3-甲氧基苯)-1,3-丁二烯-1-基)嘧啶-2(1H)-硫酮(化合物3).利用核磁共振,红外光谱和质谱表征了化合物的结构.对化合物3进行DPPH自由基清除能力和高铁离子还原能力测试(FRAP),结果表明:化合物3具有一定的抗氧化活性.该新反应环境友好、无毒、无污染,操作简便、原子经济.     

几种Keggin型多金属氧酸盐的合成及性质研究

合成了几种缺位型(1:11及1:9)型多金属氧酸盐,利用IR、UV对其进行了表征,并且研究了其热稳定性,结果表明:所有的样品均具有keggin结构,且由于缺位结构的存在,热稳定性也下降.     

调控HIV-1转录和潜伏激活的机制及相关因子(英文)

(1)反式激活蛋白(Tat)是病毒复制的重要因子,正性转录延伸因子b(P-TEFb)是Tat反式激活HIV-1转录所必需的特异性宿主细胞因子,其活性与HIV-1的转录密切相关。(2)在细胞内,无活性7SK snRNP复合体是功能性有活性P-TEFb的贮存和来源。在特定条件下,7SK snRNP复合体发生解离并释放出P-TEFb,从而刺激转录延伸。可以说,P-TEFb的活性受到严格的调控,维持着一种动态的平衡。(3)同时,P-TEFb还存在于一个具有超高转录活性的超级延伸复合体(SEC)中。Tat能将含有两个延伸因子P-TEFb和ELL2的SEC复合体募集至HIV-1长末端结构域(LTR),然后众多因子协同作用有效地增强HIV-1的转录作用。(4)溴区包含蛋白4(Brd4)像Tat一样,将P-TEFb募集至众多细胞基因的启动子区域,促进转录。Brd4也可激活基础水平的HIV-1转录,却对依赖Tat的HIV-1转录具有抑制作用,因为Brd4和Tat竞争性地与P-TEFb结合。(5)鉴于Brd4对Tat依赖性HIV-1转录的抑制作用,寻找能够抑制Brd4的小分子药物,激活HIV-1潜伏,结合高效抗逆转录病毒治疗(HAART),使得彻底根除HIV-1变成可能。Brd4的抑制剂JQ1就是这样的一种小分子,并且已被证明可以在多种细胞模型中激活HIV-1潜伏。     

构树的化学特性和药理作用研究进展

综述了国内外对构树(Broussonetia papyrifera)化学成分和药理作用的研究进展,现代研究表明:从构树中分离得到的化合物对超氧化物歧化酶显示出较高的抑制活性,能够抑制酪氨酸酶的活性,具有强烈抑制类脂氧化作用,桦木醇和桦木酸对抗疼痛和抗炎效果较好,对凝血酶引起的血小板凝聚亦有强烈的抑制作用,具有很强的抗真菌作用,可显著抑制ⅡA和v型sPLA2s的活性,且对HepG2细胞有较高的细胞毒作用,还有些化合物对α-葡萄糖苷酶的抑制活性检测结果具有较好的α-葡萄糖苷酶抑制活性.该属植物中已发现的各类化学成分及其药理作用可为开发新药提供依据.     

Screening the active constituents of Chinese medicinal herbs as potent inhibitors of Cdc25 tyrosine phosphatase, an activator of the mitosis-inducing p34cdc2 kinase

Objective: To screen and evaluate the active constituents of Chinese medicinal herbs as potent inhibitors of Cdc25 phosphatase. Methods: The affinity chromatography purified glutashione-S-transferase/Cdc25A phosphatase fusion protein and Cdc2/cyclin B from the extracts of starfish M phase oocytes are used as the cell cycle-specific targets for screening the antimitotic constituents. We tested 9 extracts isolated from the Chinese medicinal herbs and vegetables including the agents currently used in cancer treatment by measuring the inhibition of Cdc25A phosphatase and Cdc2 kinase activity. The antitumor activity of the extracts was also evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and flow cytometry. Results: Cdc25A inhibitory activity and antitumor activity are detected in the extracts isolated from three Chinese medicinal herbs Agrimona pilosa; Herba solani lyrati; Galla chinesis. Conclusion: We found three extracts isolated from Chinese medicinal herbs have potential inhibitory activity of Cdc25 phosphatase using a highly specific mechanism-based screen assay for antimitotic drug discovery.     

Chemical composition and antibacterial activity of <Emphasis Type="Italic">Gongronema latifolium</Emphasis>

Chemical composition of Gongronema latifolium leaves was determined using standard methods. Aqueous and methanol G. latifolium extracts were tested against thirteen pathogenic bacterial isolates. Crude protein, lipid extract, ash, crude fibre and nitrogen flee extractives obtained are： 27.2%, 6.07%, 11.6%, 10.8% and 44.3% dry matter respectively. Potassium, sodium, calcium, phosphorus and cobalt contents are 332, 110, 115, 125 and 116 mg/kg respectively. Dominant essential amino acids are leucine, valine and phenylalanine. Aspartic acid, glutamic acid and glycine are 13.8%, 11,9% and 10.3% respectively of total amino acid. Saturated and unsaturated fatty acids are 50.2% and 39.4% of the oil respectively. Palmitic acid makes up 36% of the total fatty acid. Extracts show no activity against E. faecalis, Y. enterolytica, E. aerogenes, B. cereus and E. agglomerans. Methanol extracts were active against S, enteritidis, S. cholerasius ser typhimurium and P. aeruginosa （minimum inhibitory concentration （MIC） 1 mg; zone of growth inhibition 7, 6.5 and 7 mm respectively）. Aqueous extracts show activity against E. coli （MIC 5 mg） and P. aeruginosa （MIC 1 mg） while methanol extracts are active against P. aeruginosa and L. monocytogenes. G. lafifolium has potential food and antibacterial uses.     

Antibacterial and antifungal activities of different parts of Tribulus terrestris L. growing in Iraq

Antimicrobial activity of organic and aqueous extracts from fruits, leaves and roots of Tribulus terrestris L., an Iraqi medicinal plant used as urinary anti-infective in folk medicine, was examined against 11 species of pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Corynebacterium diphtheriae, Escherichia coli,Proteus vulgaris, Serratia marcescens, Salmonella typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans using microdilution method in 96 multiwell microtiter plates. All the extracts from the different parts of the plant showed antimicrobial activity against most tested microorganisms. The most active extract against both Gram-negative and Gram-positive bacteria was ethanol extract from the fruits with a minimal inhibitory concentration (MIC) value of 0.15 mg/ml against B. subtilis,B. cereus, P. vulgaris and C. diphtheriae. In addition, the same extract from the same plant part demonstrated the strongest antifungal activity against C. albicans with an MIC value of 0.15 mg/ml.     

熊果酸和齐墩果酸 D-苯甘氨酸缀合物的合成、表征及抗癌活性研究

熊果酸和齐墩果酸为同分异构体,同属五环三萜类化合物,具有多种生物活性,如抗肿瘤、抗HIV、抗炎、降糖、保肝、抗疟等生物活性。本文以具有一定生物活性的熊果酸和齐墩果酸为先导化合物,通过对它们C．28位甲酯化及C．3位导入D-苯甘氨酸,共设计合成了4种未见报道的熊果酸、齐墩果酸衍生物,利用IR和1HNMR波谱技术对其结构进行了表征。然后对目标产物进行了人神经胶质瘤U87AGEFR细胞和人肺癌细胞PC9／G体外抗癌活性测试。结果表明U-3对两种癌细胞的抑制作用明显优于熊果酸和齐墩果酸。     

襄麦冬粗提物抗菌活性初步研究

以蒸馏水、甲醇、乙酸乙酯为溶剂,提取襄麦冬活性物质,并分别测定提取物对以下5种病原真菌：立枯丝核菌Rhizoctonia solani,灰葡萄孢菌Botrytis cinerea,齐整小核菌Sclerotium rolfsii,终极腐霉Pythium ultimum,尖镰孢菌黄瓜转化型Fusarium oxysporum f.sp cucumber菌丝生长和孢子萌发的抑制作用.结果表明襄麦冬的三种溶剂提取物对灰葡萄孢菌、终极腐霉、立枯丝核菌的菌丝生长均具有较强的抑制作用,而上述相同浓度的提取物对齐整小核菌、尖镰孢菌黄瓜转化型的生长未表现出明显的抑制效果.同时,三种溶剂提取物对立枯丝核菌、灰葡萄孢菌、齐整小核菌、终极腐霉、尖镰孢菌黄瓜转化型的孢子萌发均表现出一定的抑制作用.其中,襄麦冬乙酸乙酯提取物较蒸馏水和甲醇提取物对病原真菌的生长和孢子萌发的抑制效果明显.乙酸乙酯提取物相对于蒸馏水、甲醇提取物有较好的抑菌效果.襄麦冬提取物对灰葡萄孢菌、终极腐霉、立枯丝核菌的菌丝生长和立枯丝核菌、灰葡萄孢菌、齐整小核菌、终极腐霉、尖镰孢菌黄瓜转化型的孢子萌发有良好的抑制作用.     

nm23在食道癌、胃肠癌组织中的表达及其意义

目的:探讨nm23在食道癌、胃肠癌发展中的作用及其意义。方法:应用S-P免疫组织化学方法检测nm23基因在39例食道癌、39例胃癌、42例肠癌标本中的表达。结果:无淋巴结转移组nm23阳性表达率显著高于淋巴结转移组,且nm23低表达与癌的浸润深度有关;与患者的性别、癌的分化程度等生物学行为无关。结论:食道癌、胃肠癌nm23低表达者具有较强的浸润转移能力,nm23可作为预测食道癌、胃肠癌转移及预后的临床指标。     

Dielectric Properties of ZnTiO3 Microwave Ceramics Consolidated with MgTiO3

STABILIZED ZNTIO, WAS PREPARED BY DOPING MAGNESIUM OXIDE THROUGH TRADITIONAL SOLID-STATE REACTION. THE EXPERIMENTAL RESULTS INDICATE THAT ZINC TITANATE CRYSTALS DOPED WITH MAGNESIUM OXIDE GROW WELL AND THE DECOMPOSITION INTO ZN2TIO4 AND TIO2 IS RESTRAINED THROUGH TRADITIONAL SOLID STATE REACTION. BY ADJUSTING MOLAR RATIO OF MGO, BETTER PROPERTIES CAN BE OBTAINED. THE DIELECTRIC PROPERTIES OF THE CERAMICS DOPED WITH 30% MGO( MOLAR PERCENTAGE) SINTERED AT 1 060 ℃ ARE AS FOLLOWS:THE VALUE OF QUALITY FACTOR IS GREATER THAN 20 000(6. 5 GHZ), THE TEMPERATURE COEFFICIENT OF RESONANCE FREQUENCY IS ABOUT 2 × 10-6/℃, THE DIELECTRIC CONSTANT RANGES FROM 18 TO 22. BESIDES, IT IS PROVED THAT HEAT TREATMENT CAN OPTIMIZE MICROSTRUCTURE AND THE VALUE OF QUALITY FACTOR, WHICH INCREASES FROM 23 833.93 TO 47 584.00 AFTER 2 H OF HEAT TREATMENT AT 1 040 ℃.     

Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

三种常见植物体外抑菌活性的初步研究

以金黄色葡萄球菌、大肠埃希氏菌和沙门氏菌为检测菌,考察爵床、仙鹤草和鸡矢藤的水提物的体外抗菌活性。结果表明,以上三种植物水提物对所测病原菌都具有一定的抑菌效果,其中爵床对金黄色葡萄球菌抑菌活性最强,鸡矢藤对沙门氏菌抑菌活性最强,两者的最小抑菌浓度均为0.0625g·mL-1。而且各植物水提物在酸性环境等条件下不影响其抑菌活性。     

Application of Box-Behnken design in optimization of allelopathic effects of Potamogeton pectinatus against Microcystis aeruginosa

Allelopathic effects of submerged macrophytes against algae are affected by many environmental factors which can only be measured one by one by traditional methods. Box-Behnken design of response surface methodology was used to optimize three environmental factors(temperature, light intensity and total dissolved solids) of allelopathic effects of Potamogeton pectinatus against Microcystis aeruginosa at the same time. By solving the regression equation and analyzing the response surface contour plots, the optimal conditions of the relatively inhibitory rate of Microcystis aeruginosa were that the temperature was 23℃, the light intensity was 2,700,lx and the total dissolved solids were 4,415,mg/L. Under these conditions, the optimal value of relatively inhibitory rate of Microcystis aeruginosa was 81.9%. According to validation experiments, the results of analysis indicated that the experimental values fitted well with the predicted ones.