Pore-Environment-Dependent Photoresponsive Oxidase-Like Activity in Hydrogen-Bonded Organic Frameworks

Mimicking the bioactivity of native enzymes through synthetic chemistry is an efficient means to advance the biocatalysts in a cell-free environment, however, remains long-standing challenges. Herein, we utilize structurally explicit hydrogen-bonded organic frameworks (HOFs) to mimic photo-responsive oxidase, and uncover the important role of pore environments on mediating oxidase-like activity by means of constructing isostructural HOFs. We discover that the HOF pore with suitable geometry can stabilize and spatially organize the catalytic substrate into a favorable catalytic route, as with the function of the native enzyme pocket. Based on the desirable photo-responsive oxidase-like activity, a visual and sensitive HOFs biosensor is established for the detection of phosphatase, an important biomarker of skeletal and hepatobiliary diseases. This work demonstrates that the pore environments significantly influence the nanozymes’ activity in addition to the active center.     

Catalyst- and Oxidant-Free Electrochemical Regioselective Halogenation and Trifluoromethylation of 4H-Pyrido[1,2-a]pyrimidin-4-ones

The catalyst-free electrochemical halogenation and trifluoromethylation of 4H-pyrido[1,2-a]pyrimidin-4-ones was realized under external-oxidant-free conditions. This strategy provides an easy and green access to functionalized new 4H-pyrido[1,2-a]pyrimidin-4-one derivatives with broad scope, good functional group tolerance and high regioselectivity.     

Tailored Zwitterionic Hemicyanine Reporters for Early Diagnosis and Prognostic Assessment of Acute Renal Failure

Drug-induced renal failure (DIRF) poses a serious medical complication with high mortality risk. However, early diagnosis or prognosis of DIRF remain challenging, as current methods rely on detecting late-stage biomarkers. Herein we present a library of zwitterionic unimolecular hemicyanines (ZCs) available for constructing activatable reporters to detect DIRF since its initial stage. Zwitterionic properties of these probes are achieved through interspersedly integrating alkyl sulfonates and quaternary ammonium cations onto hemicyanine skeleton, which result in record low plasma protein binding (<5 %) and remarkable renal clearance efficiencies (≈96 %). An activatable reporter ZCRR is further developed by masking the optimal candidate ZC6 with a tetrapeptide specifically cleavable by caspase-8, an initiating indicator of apoptosis. In living mice with cisplatin-induced DIRF, systematically administered ZCRR efficiently accumulates in kidneys and responds to elevated caspase-8 for near-infrared fluorescence signals ‘turn-on’, enabling sensitive detection of intrarenal apoptosis 60 h earlier than clinical methods, and precise evaluation of apoptosis remediation effects by different medications on DIRF mice. As it's urinary excretable, ZCRR also allows for remote detection of DIRF and predicting renoprotective efficacy through in vitro optical urinalysis. This study thus presents unimolecular renal clearable scaffolds that are applicable to developing versatile activatable reporters for renal diseases management.     

Iodine(III)-Mediated Migratory gem-Difluorinations: Synthesis of β Transformable Functionality Substituted gem-Difluoroalkanes

Geminal-difluoroalkanes featuring intriguing steric and electronic properties are of great significance in medicinal chemistry, and great progresses have been achieved for their synthesis. In recent years, iodine(III) reagent-mediated migratory gem-difluorination of alkenes has proved to be an efficient and powerful strategy to access to diverse gem-difluoroalkanes, especially those bearing a readily transformable functionality (TF), which are important for rapid assembly of complex gem-difluorinated molecules in a modular and diverse manner. In this review, we systematically summarize the recent development of iodine(III)-mediated migratory gem-difluorination reactions for the synthesis of gem-difluoroalkanes bearing a synthetically versatile TF at the β position. The reaction mechanism and the utilities of the products are also discussed. This review is presented and grouped basically according to the types of transformable functionalities within the products.     

罗丹明B分子印迹固相萃取小柱的研制及应用

研制一种对罗丹明B具有特异性识别性能的分子印迹固相萃取小柱。用沉淀聚合法制备罗丹明B分子印迹聚合物,通过静态平衡吸附实验及固相萃取实验表征其性能,并对市售辣椒样品中的罗丹明B进行测量。罗丹明B模板聚合物的吸附能力明显优于空白聚合物;印迹固相萃取小柱对罗丹明B标准溶液(0.05 mmol/L)一次性萃取率为98.24%,实际样品测量的回收率为90.0%~95.0%,测定结果的相对标准偏差为0.9%~1.7%(n=3)。罗丹明B分子印迹固相萃取小柱选择性好、萃取率高,可应用于食品、化妆品检测等相关领域。     

1,3,5-苯三甲醛的合成与应用研究进展

介绍了1,3,5-苯三甲醛的合成与应用。在1,3,5-苯三甲醛的众多合成方法中,以氧化还原方法最常见,此外水解、聚合等方法各具优点,在满足高产率和绿色化学方面有了更多选择。1,3,5-苯三甲醛是一种具有广泛开发应用前景的化学合成中间体,以其为原料合成的大分子物质具有优异的化学、物理特性和生物活性,在催化、光电、抗病毒,以及分子吸附和药物包材等方面具有广泛的应用。     

羧基亚胺配体的合成及其促进Suzuki偶联反应的研究

合成了4种羧基亚胺配体并将其用于促进Suzuki偶联反应。通过考察配体结构、溶剂极性、碱强度和温度等因素对反应产率的影响,确定了羧基亚胺配体参与的钯催化Suzuki偶联反应的最佳条件为:催化剂的量为0.001(mol)%的Pd Cl2和0.002(mol)%的配体,以碳酸钾作碱,4m L乙醇水溶液(1∶1,体积比)作溶剂,反应温度为60℃,在空气条件下反应。结果表明,羧基亚胺配体能够有效促进Suzuki偶联反应;在合成的配体L1~L4中,具有适当的位阻和给电子基团的L2的催化活性最高,能够高效催化合成一系列联芳类化合物。     

脂肪酶Lipozyme 435催化合成海藻糖脂肪酸单酯

本文通过对溶剂系统的优化,以脂肪酶Lipozyme 435为催化剂,叔了醇/吡啶为溶剂,由海藻糖与脂肪酸的酯化反应可高选择性地合成海藻糖单脂肪酸酯.海藻糖单脂肪酸酯的溶解性能和临界胶束浓度(CMC)均随着脂肪链长度的增加而降低.预期具有合适的溶解性和CMC具有可作为安全、高效的新型增溶剂.