Thermocontrolling ion permeation through binary component membrane composed of crown ether liquid crystal/PVC

In view of the nature of orderness in structure and the mesomorphism in property of liquid crystal, the function of which is further exploited by integrating it with the feature of crown ether. The monoarmed crown ether liquid crystals are successfully applied to the imitation of biomembrane transport. Binary component membrane composed of crown ether liquid crystal and PVC was first developed. Such a novel model of biomimetic membrane is capable of imitating ingeniously the thermocontrolling transport of biomembrane, thus the essential function of liquid crystal in membane transport is more fully exploited. It was suggested, consequently, that the molecules of the crown ether liquid crystal could assemble themselves to form ionic channels, as they exist in mesophase.Of still more significance is that the thermocontrolling transport of ions through the membrane is found to be operative selectively and the permeation of ion is under the direct influence of the thermal turmoil of the crown ether liquid cr     

Biomimetic Synthesis of Ag2Se Quantum Dots with Enhanced Photothermal Properties and as “Gatekeepers” to Cap Mesoporous Silica Nanoparticles for Chemo–Photothermal Therapy

Ag₂Se quantum dots (QDs) with near‐infrared (NIR) fluorescence have been widely utilized in NIR fluorescence imaging in vivo because of their narrow bulk band gap and excellent biocompatibility. However, most of synthesis methods for Ag₂Se QDs are expensive and the reactants are toxic. Herein, a new protein‐templated biomimetic synthesis approach is proposed for the preparation of Ag₂Se QDs by employing bovine serum albumin (BSA) as a template and dispersant. The BSA‐templated Ag₂Se QDs (Ag₂Se@BSA QDs) showed NIR fluorescence with high fluorescence quantum yield (≈21.2 %), excellent biocompatibility and good dispersibility in different media. Moreover, the obtained Ag₂Se@BSA QDs exhibited remarkable photothermal conversion (≈27.8 %), which could be used in photothermal therapy. As a model application in biomedicine, the Ag₂Se@BSA QDs were used as “gatekeepers” to cap mesoporous silica nanoparticles (MSNs) by means of electrostatic interaction. By taking the advantages of NIR fluorescence and photothermal property of Ag₂Se@BSA QDs, the obtained MSN‐DOX‐Ag₂Se nanoparticles (MDA NPs) were employed as a nanoplatform for combined chemo‐photothermal therapy. Compared with free DOX and MDA NPs without NIR laser, the laser‐treated MDA NPs exhibited lower cell viability in vitro, implying that Ag₂Se@BSA QDs are highly promising photothermal agents and the MDA NPs are potential carriers for chemo–photothermal therapy.     

化学基元组学与药物创新

化学基元组学（chemomics）是与化学信息学、生物信息学、合成化学等学科相关的交叉学科．生物系统从内源性小分子（天然砌块）出发,通过酶催化的化学反应序列制造天然产物．生物系统通过化学反应和天然砌块向目标天然产物“砌入”一组原子,这样的一组原子称为化学基元（chemoyl）．化学基元组（chemome）是生物组织中所含有的化学基元的全体．化学基元组学研究各种化学基元的结构、组装与演化的基本规律．在生存压力和繁衍需求的驱动下,生物系统已经进化出有效手段来合成天然产物以应付环境的变化,并产生了丰富多彩的生物和化学多样性．近年来,人们意识到药物创新的瓶颈之一是药物筛选资源的日益枯竭．化学基元组学可以解决这个瓶颈问题,它通过揭示生物系统制备化学多样性的规律,发展仿生合成方法制备类天然化合物库（quasi natural product libraries）以供药物筛选．本文综述了化学基元组学的主要研究内容及其在药物创新各领域中的潜在应用．     

Bio‐Inspired Formal Synthesis of Hirsutellones A–C Featuring an Electrophilic Cyclization Triggered by Remote Lewis Acid‐Activation

A bio‐inspired strategy was used to complete the formal synthesis of the antitubercular hirsutellone B and congeners A and C, through construction of its decahydrofluorene core from a linear polyene strand activated at both ends by a silyl enol ether and an allyl acetate. Our synthesis features a key electrophilic cyclization, starting with the remote activation (by [Yb(OTf)₃] or BF₃ ? OEt₂) of the allyl acetate and stereoselectively affording the C ring. This was followed by an intramolecular Diels–Alder reaction to get the tricyclic core of the natural product. The stereoselective reduction of the resulting ketone towards the formal intermediate was critical to the success of this strategy.