壳聚糖改性及用其整理纺织品抗菌性能的研究

用羟甲基化和醚化等方法制备了改性壳聚糖羟甲基壳聚糖和羟乙基乙基醚壳聚糖。在中性条件下它们溶解于水。实验显示，改性壳聚糖具有较好的抑菌作用和吸湿保湿性能。对织物进行的后整理实验发现，羟乙基乙基醚壳聚糖适用于对棉布的整理加工，羟甲基壳聚糖适用于对真丝绸的整理加工。经整理后的织物具有较好的抗菌性，且吸湿、透湿、染色性能较优。研究表明改性壳聚糖可作为优良的功能性天然“绿色”纺织品整理剂。     

选矿流程样品中铌和钍的X射线荧光光谱法测定

采用Ｘ射线荧光光谱法，以铑靶的康普顿散射线强度为内标，测定了铁矿石选矿流程样品中的铌和钍。方法简便、快速、准确，完全能够满足选矿工艺研究和日常生产对样品中铌和钍分析的要求。     

Asymmetric synthesis of highly functionalized tyrosine derivatives for the construction of bistetrahydroisoquinoline alkaloids

A novel and facile synthesis of l-5-hydroxy-2,4-methoxy-3-methylphenylalanine derivatives, which are the key coupling partners for the asymmetric total synthesis of natural bistetrahydroisoquinoline alkaloids, is realized starting from l-tyrosine with 17% overall yield. The synthesis has been carried out on a multigram scale featuring the following key steps: (a) transformation of phenol to dihydroquinone via salcomine-catalyzed oxidation followed by zinc-acetic acid reduction; (b) single TBS-protection of dihydroquinone; (c) Mitsunobu methylation of the newly generated phenolic hydroxyl group.     

Photocatalytic anion oxidation achieves direct aerobic difunctionalization of alkenes leading to β-thiocyanato alcohols

A novel visible light-driven oxidative cascade reaction for the synthesis of β-thiocyanato alcohols via difunctionalization of alkenes is described for the first time. In this protocol inorganic ion thiocyanate was successfully converted into radical through photocatalysis by employing Rose Bengal as a photocatalyst to mediate the single-electron transfer. This hydroxylation process did not need extra reducing agent and the new CS and CO bonds could be constructed in one pot. Molecular oxygen not only was used as an excellent terminal oxidant, but also served as a green oxygen source, which is one of the most ideal processes to realize CH bond oxidation functionalization. Moreover, the reaction also proceeded very well under irradiation of sunlight.     

Molecular dynamics study of salt effects on micellization of N-dodecyl-N,N-dimethyl-3-ammonio-1-propane-sulfonate

In this paper, molecular dynamics simulation methods were used to investigate salt effects on micellization of N-Dodecyl-N,N-Dimethyl-3-Ammonio-1-Propane-sulfonate (SB12-3) in aqueous solution. It is proved that micelle shapes transform from spherical to prolate spherical shape after 30.0?ns simulation with different NaCl and CaCl₂ concentration. By comparison with the eccentricity value without salt addition, SB12-3 shows salt tolerance behaviors due to its unique “inner salt” structure of amphiphilic surfactant. Radial distribution function (RDF), hydrophobic groups solvent accessible surface area (SASA), hydrogen bond, and the deuterium order parameter (S_CD) are to elucidate salt effects on SB12-3 micelle formation. The radius of micelle is achieved by the related RDF value and in accordance with other researches. The addition of NaCl and CaCl₂ didn’t change the structure of micelle significantly and have little effects on the interactions between SB12-3 and water molecule. By comparison with the results without salt system, SASA of hydrophobic groups is almost the same, and SASA of hydrophilic groups and total molecule fluctuates only slightly. This further indicates that the surface of micelles is more hydrophilic due to the strong interactions between SB12-3 and water molecules. The existence of NaCl and CaCl₂ will enhance the hydrophilic interactions.     

Intermolecular [2+2] photocycloaddition of chalcones with 2,3-dimethyl-1,3-butadiene under neat reaction conditions

The intermolecular [2 + 2] photocycloaddition of chalcones with 2,3-dimethyl-1,3-butadiene under visible-light irradiation for the synthesis of cyclobutane derivatives has been developed. Without using any photosensitizer, metallic catalyst and solvent, the reaction proceeded with high regioselectivity and moderate to high stereoselectivity. Mild reaction conditions and no additives make the reaction easy to operate. Control experiments and density functional theory (DFT) computations demonstrated that the reaction takes place via visible-light activation of chalcones, which is different from the previously reported [2 + 2] cycloaddition of chalcones.     

Design,synthesis, and fungicidal activity of novel 1,3,4-oxadiazole derivatives

Employing the intermediate derivatization method (IDM), a series of 1,3,4-oxadiazole derivatives containing arylpyrazoloxyl moiety were designed and synthesized. In vitro bioassays showed that these compounds have moderate to significant fungicidal activity against rice sheath blight and sorghum anthracnose. Furthermore, compound 20 is a promising fungicide for further development.     

Effects of degree of substitution on stearic acid-modified Bletilla striata polysaccharides nanoparticles and interactions between nanoparticles and bovine serum albumin

A stearic acid-modified Bletilla striata polysaccharides nanoparticle was fabricated. The effects of degree of substitution on its characteristic properties, the interactions of nanoparticles with bovine serum albumin and cell toxicity were assessed.