Nitraza-/Oxa-Propylene- and Hydrazonemethylene-Bridged 1,2,4-Nitraminotriazoles and Selected Salts

Two new bridged nitraminotriazoles with bridging oxapropylene and nitrazapropylene moieties were synthesized, and converted into several salts, as well as from the hydrazonemethylene bridged nitraminotriazole. All compounds were fully characterized by NMR and IR spectroscopy, elemental analysis as well as differential thermal analysis. The sensitivity towards friction and impact were determined according to BAM standard technics and the energetic properties were calculated by using the EXPLO5 computer code. The neutral compounds as well as the various salts were examined in terms of their physicochemical properties and detonation performance to each other and compared to the commonly used secondary explosive RDX.     

含嘧啶环的苯基磺酰脲、吡唑磺酰脲的合成及生物活性

磺酰脲衍生物;除草活性;含嘧啶环的苯基磺酰脲、吡唑磺酰脲的合成及生物活性     

烷基二茂铁的合成及性质

电化学性质;燃速催化性;烷基二茂铁的合成及性质     

系列甘露糖醛酸寡糖的制备与鉴定

用酸降解法制备了系列甘露糖醛酸寡糖(聚合度2～8),并分析测定了寡糖的结构. 褐藻胶经部分酸水解,于pH=2.85处分级获得聚甘露糖醛酸. 继续用酸降解法降解聚甘露糖醛酸,经凝胶柱层析分离纯化,获得系列甘露糖醛酸寡糖. 用荧光标记糖电泳(FACE)对寡糖进行了分析,并用电喷雾离子化质谱(ESI-MS)、 核磁共振波谱(NMR)及红外光谱(FTIR)进行了结构表征. 本研究用酸降解法制备饱和甘露糖醛酸寡糖,用凝胶柱层析法分离获得系列聚合度的寡糖,为褐藻胶大分子构效关系研究和药物的筛选与发现提供了重要的基础资料.     

Pd/ZnO和Ag/ZnO复合纳米粒子的制备、表征及光催化活性

 用焙烧前驱物碱式碳酸锌的方法制备了ZnO纳米粒子，采用光还原沉积贵金属的方法制备了Pd／ZnO和Ag／ZnO复合纳米粒子，并利用ICP，XRD，TEM和XPS等测试技术对样品进行了表征，初步探讨了贵金属在ZnO纳米粒子表面形成原子簇的原因．以光催化氧化气相正庚烷为模型反应，考察了样品的光催化活性以及贵金属沉积量对催化剂活性的影响．结果表明：沉积适量的贵金属，ZnO纳米粒子光催化剂的活性大幅度提高．同时，深入探讨了表面沉积贵金属的ZnO纳米粒子光催化剂活性有所提高的内在原因．     

Isolation and characterization of R-phycoerythrin subunits and enzymatic digests

Subunits and enzymatic digests of the highly fluorescent phycobiliprotein R-phycoerythrin (R-PE) were analyzed by several separation and detection techniques including HPLC, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), CE, and HPLC-electrospray ionization (ESI) MS. R-PE subunits were isolated by HPLC and detected as single molecules by total internal reflection fluorescence microscopy. The results show efficient absorption and fluorescence of the R-PE subunits and digest peptides, originating from the incorporation of phycoerythrobilin and phycourobilin chromophores in them. In addition, HPLC-ESI-MS and SDS-PAGE were optimized to determine the molecular masses of phycobiliprotein subunits and the chromophore-containing peptides, as well as the amino acid sequences of the latter. Favorable spectroscopic and structural properties of R-PE subunits and enzymatic digests, even under denaturing conditions, make these molecules suitable for use as fluorescence labels for biomolecules.     

Influence of heating and cooling rates on the glass transition temperature and the fragility parameter of sorbitol and fructose as measured by DSC

The glass transition temperatures of sorbitol and fructose were characterized by four points determined on DSC heating thermograms (onset, mid-point, peak and end-point), plus the limit fictive temperature. The variations of these temperature values, observed as functions of cooling and heating rates, were used to determine the fragility parameter, as defined by Angell [1] to characterize the temperature dependence of the dynamic behavior of glass-forming liquids in the temperature range above the glass transition. The apparent activation energy values, determined for the different temperatures studied, were similar for fructose and sorbitol. These values were compared to data obtained from other techniques, such as mechanical spectroscopy. The variations of the apparent activation values, observed in experiments involving cooling and heating at the same rate, slow cooling followed by rate-heating, or rate-cooling followed by fast heating, were explained by aging effects occurring during the heating step.     

Phenolic compounds,antioxidant activity and Cu,Zn, Cd and Pb content in wild and cultivated cranberries and blueberries

The aim of this study was to determine the content of Cu, Zn, Cd and Pb and the total polyphenol (TP) content as well as the total antioxidant capacity (TAC) in wild cranberries and blueberries collected from different localities of the Slovakia and to compare them with properties of six cranberry and six highbush blueberry cultivars obtained from the research centre. Compared with cultivated cranberries (Cu, Zn, Cd and Pb content: 0.642, 1.496, 0.015 and 0.050 mg/kg FM) in wild fruits, higher Cu (by 37%) and lower Zn, Cd and Pb (by 8%, 7% and 44% respectively) were determined using atomic absorption spectrometry method. In wild blueberries, higher Cu, Zn and Pb (by 16%, 209% and 80% respectively) and similar Cd contents were determined compared with cultivated fruits (Cu, Zn, Cd and Pb content: 0.483, 0.541, 0.003 and 0.055 mg/kg FM). The TP contents estimated by spectrophotometry using Folin–Ciocalteau reagent were in intervals 1405–3161 (cranberries) and 1300–3077 (blueberries) expressed as mg GAE/kg FM. While the average TP content determined in wild cranberries was by 31% lower than that in cultivated cranberries, in wild blueberries it was by 97% higher compared with highbush blueberry cultivars. The values of TAC determined by spectrophotometry method using 2,2-diphenyl-1-picrylhydrazyl were in range 20.67–22.22 (cranberries) and 14.03–24.79 (blueberries) expressed as mmol TE/kg FM. In wild cranberries and blueberries, the lower average TAC values compared with cultivated berries were determined (by 1% and 28%, respectively).     

Syntheses and reactions of porphyrin and metalloporphyrin polymers

Various porphyrin functions such as protoporphyrin IX and chlorin a as well as metalloporphyrin functions such as Mg(II)– and Cu(II)–chlorophyllin a and Fe(III)– and Co(II)–protoporphyrin IX were incorporated into vinyl polymers by preparation and polymerization of their p-vinylbenzyl esters. The porphyrin function was also incorporated by reaction of poly-p-chloromethylstyrene with porphyrins or metalloporphyrins or by the reaction of p-aminostyrene polymers with chlorophyll b through Schiff-base formation. Mg(II)–porphyrin polymers were found to be remarkably effective as catalysts in photoredox systems; porphyrin polymers without central metal atoms were also effective to a lesser extent.     

Synthesis and Characterization of Star-branched Polyisobutylene by Combination of Anionic Polymerization and Cationic Polymerization

The construction of polymer materials with controlled compositions, topologies, and functionalities has been the enduring focus in current research1,2. Among them, star polymers have been extensively studied for a long time, due to their markedly lower so…     

Ionization and Tautomerism of Hydroxyxanthenes and Some Other Dyes in Ethanol

Protolytic equilibria of hydroxyxanthene dyes, Fluorescein, Eosin, as well as of some relatedcompounds, in ethanol were studied by spectrophotometry. Stepwise ionization and tautomeric equilibriumconstants were determined.     

Inhibition and labeling of enzymes and abzymes by phosphonate diesters

Reactive phosphonate diesters were designed and prepared as inhibitors of serine proteases and esterases. Inactivation of trypsin, chymotrypsin, and butyrylcholinesterase was determined by residual enzymaticactivity as well as by the release of a chromogenic or fluorogenic product of the inhibition reaction. Second-order rate constants were determined from rates of nitrophenol formation. Application of the reaction for active-site titration of enzyme preparations is demonstrated. A basic functional group present in the nitrophenyl tropane phosphonate diester was shown to confer selectivity for inactivation of try psin and chymotrypsin. Biotinylated derivatives of the phosphonate diesters were prepared to permitanalysis of proteins modified in the inhibition reaction. Labeled polypeptides were resolved by SDSPAGE, electroblotted, and detected by streptavidin-peroxidase staining. A detection limit of less than 4 ng, corresponding to 20 nM of trypsin, was demonstrated. Pretretment of enzymes with DFP or nonbiotinylated phosphonates specifically blocks the labeling. This technique permits identification of serine proteases in complex mixtures with good sensitivity and specificity.     

Preparation and characterization of phenyl and undecyl oxazoline block copolymers

Undecyl and phenyl oxazolines were synthesized. They were copolymerized in different mole ratios using methyl nosylate as initiator. A series of di- and triblock copolymers with narrow molecular weight distributions as indicated by GPC were obtained. A three-armed block copolymer was also obtained by using 1,3,5-tris(bromomethyl)benzene as initiator. When the nonpolar undecyl block crystallized as a coating, the critical surface energy approached 21.0 dyn/cm, and the contact angle of water on the surface could be higher than 107°. The melting point increased as the chain length of crystallizable undecyl block increased, and the melting peak on DSC was very sharp when the length was equal to or longer than 25 monomer units. When these copolymers were coated on substrates, the work of adhesion with pressure sensitive adhesives was greatly reduced.     

Three-dimensional structural features and the toxicity of aminobenzenes and phenols

There are many organic pollutants in the environment, such as polychlorinated biphenyl, polycyclic aromatic hydrocarbons, dichlorodiphenyl-trichloroethane (DDT), and polychlorinated naphthalene. These organic pollutants are persistent,liposoluble and easily cumulated in organism; consequently, the potential toxicity will be high. Risk assessment of industrial chemicals is currently carried out using scanty experimental data, because many of these chemicals have very little or no test data. S…     

Synthesis and properties of new polyazines—I

New polyazines were synthesized by the polycondensation of hydrazine with acenaphthenequinone, 5-chloroacenaphthenequinone, 5-nitroacenaphthenequinone and 5,6-dinitroacenaphthenequinone. The influences of the catalyst and quinone/hydrazine mole ratio on the yield of soluble and insoluble compounds, as well as on the viscosity of a solution of the polymer in DMF, were studied. Some electrophysical properties as well as the polyazine behaviour under heating were also studied by thermogravimetrical analysis.     

General Discussion on Thermal and Photodegradation and Stabilization

Indole-containing bifunctional monomers (diacids, dialcohols, and dialdehydes) were synthesized by using as the basic nucleus two indoles attached by a tetraethylene glycol chain. These monomers were used for the preparation of polyesters, poly-amides, and polyazomethines.     

Tuning size and catalytic activity of nano-clusters of cobalt oxide

Cobalt oxides were prepared by three different methods: (1) by reacting cobalt nitrate with oxalic acid, (2) co-precipitating cobalt nitrate with sodium carbonate, and (3) using sodium dodecyl sulphate as organic surfactant. All three samples were characterized before and after calcination by solvent extraction and the resulting products examined by IR spectroscopy. In the case of method 3, the removal of surfactant was followed by TGA studies. Products from all three methods were identified by XRD. Peaks in low angle XRD indicate the porous nature of the oxides. The morphology of the pores was studied by transmission electron microscopy. Some irregular pore structures were obtained for samples from methods 1 and 2, with an average size of 4–6 nm. Only the product from method 3 using SDS as template showed ordered structure and optimum size, and Brunauer-Emmet-Teller surface areas of the as-prepared, as well as the treated samples, exhibited H3 type hysteresis. The samples from the three methods were used as catalysts in the oxidation reaction of cyclohexane under mild conditions and the catalytic efficiency of the cobalt oxide was comparable with mesoporous cobalt oxides.     

光致变色微胶囊的制备与性能

以蜜胺树脂为壁材、光致变色材料为芯材,采用原位聚合法制备了具有光致变色性能的微胶囊.研究了三聚氰胺/甲醛摩尔比、壁材与芯材的用量比、乳化剂浓度等因素对微胶囊形貌及性能的影响.在最佳工艺条件下制备的变色微胶囊,在日光和紫外光下具有快速、可逆的光致变色性能.     

柔红霉素和阿霉素自旋标记衍生物的合成与抗肿瘤活性

合成了5个新的柔红霉素及阿霉素的氮氧自由基自旋标记衍生物(5_9),经元素分析,IR,MS和ESR分析确证了其组成和结构,并对它们进行了抑制小鼠白血病P388、小鼠黑色素癌B16、人胃腺癌MGC和人肝癌SMMC7721细胞的体外筛选.初步药理试验表明,化合物5_9对4种瘤株均有一定的抑制活性,其中化合物9的活性与阿霉素相当.     

环状多聚二硫醚化合物的合成及初步生物活性研究

通过二硫醇化合物氧化的方法合成了8个具有环状结构的多聚二硫醚化合物. 得到的化合物经IR, ¹H NMR, ¹³C NMR和HREIMS确证其结构, 部分化合物还经晶体X衍射方法验证. 通过对II型糖尿病靶标蛋白酪氨酸磷酸酯酶(PTP1B)抑制活性的分析, 发现一些化合物具有一定的PTP1B抑制活性.