Synthesis and antibacterial activity of brominated 2′(4′)-nitro-3-hydroxy diphenyl ethers

Eight new brominated 2＇（4＇）-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by ^1H NMR, IR and HRMS. The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria. These new compounds cannot be transformed into dioxins when they were manufactured and used.

Asymmetric synthesis of syn-aryl-(2S,3R)-2-chloro-3-hydroxy esters via an engineered ketoreductase-catalyzed dynamic reductive kinetic resolution

We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kinetic resolution of racemic arylα–chloroβ-keto esters(2)catalyzed by an engineered ketoreductase which was obtained via ep PCR-based directed evolution.The hectogram scale synthesis of syn-(2S,3R)-1b at a substrate concentration of 120 g/L showcased the application potential of the biocatalytic method developed presently.

Properties of a New Dental Photocurable Matrix Resin with Low Shrinkage

In order to reduce the amount of volumetric shrinkage that occurs in dental composites as a result of curing,a new kind of dental matrix resin combining bisphenol-S-bis（3-meth acry late-2-hydroxy propyl）ether（BisS-GMA） with the expanding monomer unsaturated spiro orthoesters 2-methylene-1,4,6-trispiro[4,4] nonane （SOE） was prepared,with triethylene glycol dimethacrylate （TEGDMA） as diluent.CQ （camphorquinone） of 1wt% and DMAEMA （2-（dimethylamino） ethyl meth acrylate） of 2wt% were used as photoinitiation system to initiate the copolymerization of the matrix resins.The performance including volumetric shrinkage,degree of conversion and condition of the ring-opening reaction of SOE,as well as curing time and the tensile bond strength were investigated respectively by the dilatometer,Fourier transfer infrared,the universal testing machine,and so on.The ring-opening polymerization of SOE occurred.Meanwhile,the obtain copolymers were crosslinked.The matrix resin containing BisS-GMA and SOE showed a reduced amount of volumetric shrinkage at 1.52%,which is a promising strategy for obtaining a polymer with a low amount of volumetric shrinkage.Furthermore,the other properties were not compromised.

披针叶茴香果实的化学成分研究

目的研究八角科（Illiciaceae）植物披针叶茴香（Illicium lanceolatum）果实的化学成分。方法应用硅胶、Sephadex LH-20、MCI等各种色谱技术进行分离纯化，根据化合物的理化常数和波谱数据鉴定其结构。结果从披针叶茴香果实的体积分数95％乙醇提取物中分离得到12个化合物，通过渡谱数据和理化常数分别鉴定为2，4-dihydroxy—allylbenzene-2-O-β-D—glucopyranoside（1），（＋）-儿茶素（2），槲皮素-3-O-β-L-鼠李糖苷（3），芦丁（4），异鼠李素-3-D-β-D-芸香糖苷（5），6-deoxy-1-hy—droxy neoanisatin（6），莽草毒素（7），icarisideE3（8），（75，8R）-urolignoside（9），对羟基苯甲酸（10），莽草酸（11），β-谷甾醇（12）。结论化合物1，4～6，8～10为首次从该植物中分离得到。