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991.
以天然樟脑为原料,经中间体樟脑肟和樟脑胺,以及樟脑胺与取代苯甲酰氯的N-酰化反应,合成得到9个樟脑基苯甲酰胺类化合物(3a~3i)。初步探索了合成条件,并通过FT IR、1H NMR、13C NMR、ESIMS和元素分析等多种手段对目标产物进行结构表征。生物活性测试表明,在50mg/L浓度下,所合成的化合物对5种植物病原菌均有一定的抑制作用,其中化合物3c(R=2-Cl)和3i(R=4-F)对苹果轮纹病菌的抑制率分别达97.5%和96.4%,化合物3i对小麦赤霉病菌的抑制率为95.7%。在100mg/L浓度下,化合物对油菜的胚根生长均显示良好的抑制活性,其中化合物3b(R=4-Cl)的抑制率达97.4%。 相似文献
992.
以脱除模板剂后的SBA-15为硅源和间接模板剂,在水热条件下制备多级孔SAPO-11分子筛,并通过XRD、SEM、红外光谱、氮气物理吸附-脱附等表征手段对样品的晶相、形貌、酸性和织构性质进行表征。结果表明,以焙烧后的SBA-15为硅源合成出纯相的SAPO-11分子筛,且SBA-15已完全转化。合成的SAPO-11样品呈空心的近方柱体形貌,由宽度为100 nm左右的细条聚集而成,晶粒粒径为1-3 μm。与白炭黑、硅溶胶合成的常规SAPO-11分子筛对比发现,添加SBA-15可在SAPO-11中引入介孔孔道,孔径为5-10 nm,且样品以中强度的Brønsted酸为主,弱Brønsted酸相对较少。以正十二烷为探针分子,考察Pt/SAPO-11催化剂的临氢异构化反应性能。结果表明,多级孔Pt/SAPO-11催化剂具有优良的异构化反应性能。催化剂的高活性和选择性与SAPO-11分子筛的酸性质和孔道结构密切相关,中强度的Brønsted酸量的增加有助于活性提高,同时介孔孔道有利于产物扩散,异构产物的选择性明显提高。 相似文献
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Enhanced Photodynamic Therapy by Reduced Levels of Intracellular Glutathione Obtained By Employing a Nano‐MOF with CuII as the Active Center 下载免费PDF全文
Dr. Wei Zhang Jun Lu Dr. Xiaonan Gao Dr. Ping Li Dr. Wen Zhang Dr. Yu Ma Dr. Hui Wang Prof. Bo Tang 《Angewandte Chemie (International ed. in English)》2018,57(18):4891-4896
In photodynamic therapy (PDT), the level of reactive oxygen species (ROS) produced in the cell directly determines the therapeutic effect. Improvement in ROS concentration can be realized by reducing the glutathione (GSH) level or increasing the amount of photosensitizer. However, excessive amounts photosensitizer may cause side effects. Therefore, the development of photosensitizers that reduce GSH levels through synergistically improving ROS concentration in order to strengthen the efficacy of PDT for tumor is important. We report a nano‐metal–organic framework (CuII‐metalated nano‐MOF {CuL‐[AlOH]2}n (MOF‐2, H6L=mesotetrakis(4‐carboxylphenyl)porphyrin)) based on CuII as the active center for PDT. This MOF‐2 is readily taken up by breast cancer cells, and high levels of ROS are generated under light irradiation. Meanwhile, intracellular GSH is considerably decreased owing to absorption on MOF‐2; this synergistically increases ROS concentration and accelerates apoptosis, thereby enhancing the effect of PDT. Notably, based on the direct adsorption of GSH, MOF‐2 showed a comparable effect with the commercial antitumor drug camptothecin in a mouse breast cancer model. This work provides strong evidence for MOF‐2 as a promising new PDT candidate and anticancer drug. 相似文献
997.
Propagation of Enzyme‐Induced Surface Events inside Polymer Nanoassemblies for a Fast and Tunable Response 下载免费PDF全文
Dr. Jiaming Zhuang Dr. Hatice Seçinti Bo Zhao Prof. Dr. S. Thayumanavan 《Angewandte Chemie (International ed. in English)》2018,57(24):7111-7115
We report a new molecular design strategy that allows for the propagation of surface enzymatic events inside a supramolecular assembly for accelerated molecular release. The approach addresses a key shortcoming encountered with many of the currently available enzyme‐induced disassembly strategies, which rely on the unimer–aggregate equilibria of amphiphilic assemblies. The enzymatic response of the host to predictably tune the kinetics of guest‐molecule release can be programmed by controlling substrate accessibility through electrostatic complexation with a complementary polymer. Accelerated guest release in response to the enzyme is shown to be accomplished by a cooperative mechanism of enzyme‐triggered supramolecular host disassembly and host reorganization. 相似文献
998.
A Bio‐inspired Cu4O4 Cubane: Effective Molecular Catalysts for Electrocatalytic Water Oxidation in Aqueous Solution 下载免费PDF全文
Xin Jiang Jian Li Bing Yang Xiang‐Zhu Wei Bo‐Wei Dong Yi Kao Mao‐Yong Huang Prof. Chen‐Ho Tung Prof. Li‐Zhu Wu 《Angewandte Chemie (International ed. in English)》2018,57(26):7850-7854
Inspired by the cubic Mn4CaO5 cluster of natural oxygen‐evolving complex in Photosystem II, tetrametallic molecular water oxidation catalysts, especially M4O4 cubane‐like clusters (M=transition metals), have aroused great interest in developing highly active and robust catalysts for water oxidation. Among these M4O4 clusters, however, copper‐based molecular catalysts are poorly understood. Now, bio‐inspired Cu4O4 cubanes are presented as effective molecular catalysts for electrocatalytic water oxidation in aqueous solution (pH 12). The exceptional catalytic activity is manifested with a turnover frequency (TOF) of 267 s?1 for [(LGly‐Cu)4] at 1.70 V and 105 s?1 for [(LGlu‐Cu)4] at 1.56 V. Electrochemical and spectroscopic study revealed a successive two‐electron transfer process in the Cu4O4 cubanes to form high‐valent CuIII and CuIIIO. intermediates during the catalysis. 相似文献
999.
Yong Li Yingzheng Shu Muwen Liang Dr. Xilei Xie Dr. Xiaoyun Jiao Prof. Xu Wang Prof. Bo Tang 《Angewandte Chemie (International ed. in English)》2018,57(38):12415-12419
Carbon monoxide (CO) is proposed as an active pharmaceutical agent with promising pharmaceutical prospects, as it has been involved in multifaceted modulation of diverse physiological and pathological processes. However, questions remain for therapeutic application of inhaled CO attributed to the inherent great affinity between CO and hemoglobin. Therefore, a robust platform with the function of CO transport and controllable release, depending on the local status of an organism, is of prominent significance for effectively avoiding the side effects of CO inhalation and optimizing the biological regulation function of CO. Utilizing the oxidative stress biomarker H2O2 as a trigger and combining with photo‐control, a two‐photon H2O2‐activated CO photoreleaser, FB, featuring highly sensitive and specific H2O2 sensing and photocontrollable CO release, was developed and the vasodilation effect of CO against angiotensin II was demonstrated. 相似文献
1000.
以丹皮酚为原料,与乙酸在N,N-二甲基乙酰胺(DMAc)和SOCl2作用下反应制得乙酰丹皮酚酯(1); 1中酮羰基与盐酸羟胺反应生成相应的丹皮酚肟(2);在DMAc和CH2Cl2体系中,取代羧酸(3a~3l)与SOCl2反应生成酰氯后随即与2反应合成了系列新型丹皮酚肟酯(4a~4l),产率80.9%~95.5%,其结构经1H NMR、13C NMR、IR和MS表征。以苯甲酰丹皮酚肟酯(4a)的合成为例,对反应条件进了优化。最优反应条件为:以DMAc(2 mL)为催化剂,酰氯化反应时间为20 min,酯化反应时间为3 h,产率95.1%。并对DMAc促进丹皮酚肟酯合成反应的可能机理进行了探讨。 相似文献