金属有机框架与新型载药体系

金属-有机骨架材料(MOFs)是一类由金属离子与有机配体之间的配位自组装形成的新型多孔复合材料。因其具有高比表面积、可调的尺寸、拓扑结构多样性、合成简便、有机基团易于功能化等优点使其在生物分析、成像、传感、催化、气体存储与分离以及药物运载等领域具有广泛的应用前景。这里通过简要介绍MOFs的研究背景,基于MOFs孔径的药物装载策略以及MOFs药物释放的刺激响应方式,阐述MOFs作为药物递送载体的最新进展,为后期药物载体的设计提供参考。     

MOF基水凝胶材料的制备及其应用

近年来,金属-有机骨架材料(MOFs)因为具有优异的骨架结构、丰富的孔隙度和多功能性,吸引了众多研究者的注意,各种各样的MOFs材料和MOF基复合材料被研制。但是由于MOFs大多以晶体和粉末的形式存在,其本身的刚性和易碎性限制了它的实际应用,同时MOFs在溶液中的不稳定性会导致材料的分解,一些高结晶度的MOFs还十分脆弱易碎且不易加工,因此有研究者将MOFs与水凝胶相结合,开发出许多具有优异性能的MOF基水凝胶材料。本文综述了MOF基水凝胶材料近年的研究进展,重点介绍了MOF基水凝胶的种类及其与其他材料的协同作用,讨论了MOF基水凝胶在传感、催化、水处理、伤口敷料和药物载体等方面的优势。MOF基水凝胶具有的可加工性、稳定性、易处理性为MOFs在实际应用中的研究具有指导意义。我们概述了纯MOF水凝胶、MOF@生物有机大分子水凝胶、MOF@生物相容性水凝胶,其他MOF基复合水凝胶的最新进展以及这些复合材料的应用。     

金属有机框架复合材料的合成及其在肿瘤诊疗领域中的应用

金属-有机框架(MOF)材料是指以有机配体为连接体和以金属离子簇为节点,通过配位键组装形成的具有周期性结构的配位化合物。该材料在气相传导、光学催化以及生物应用领域都有着应用潜力。不同形貌、大小和组分的MOF材料具有不同的物理化学性质。将金属纳米粒子和MOF材料的性能相结合,就能够有效地避免金属纳米粒子和MOF材料的相互凝聚。本文主要阐述了MOF材料的几种合成方法,包括气相法、液相法、固相法、模板法、微波法和电化学法,并对其优缺点进行了讨论。重点分析了其在肿瘤领域中的应用,包括药物负载、荧光标记和光动力学疗法等。最后指出今后其主要的研究方向是改善生物相容性、降低制备成本、扩展生物MOF及其负载药物的种类,使其应用到更多疾病的治疗上。     

纳米金属有机骨架材料及其载药应用

金属有机骨架材料(MOFs)是指由含氮、氧等多齿有机配体与金属离子通过自组装形成的配位聚合物。由于金属有机骨架材料的大比表面积和高孔隙率等优点使其在药物负载领域有广泛应用。近年来,纳米金属有机骨架材料(NMOFs)因既具有MOFs的特点,又具有纳米材料独特的理化性能,使其兼具药物负载量高、目标靶向性好、表面易改性和生物相容性优良等特点,已成为一种优异的纳米级载药系统。本文介绍了NMOFs的常用制备方法,主要包括溶剂热法、反相微乳液法与超声波法,并对其优缺点进行了讨论;详细阐述了载药NMOFs的特性及其不同类型对于各类药物的负载能力;指出今后其主要的研究方向是改善生物相容性、实现更有效的表面功能化、扩展生物NMOFs及其负载药物的种类,使其应用到更多疾病的治疗上。     

金属-有机框架材料在癌症诊疗中的应用

成像技术的迅速发展使科学家和临床医生能够准确地了解癌症的发病机制和病理过程, 并根据患者的情况制定个性化的治疗策略. 将各种成像与治疗试剂整合为一体的癌症诊疗平台, 可以同时用于癌症的诊断和治疗, 受到了广泛的关注. 金属-有机框架材料(MOFs)是由有机配体和金属离子/离子簇自组装而成的一种有趣而独特的多孔有机-无机杂化材料. 由于其易于后修饰、 孔隙和结构可设计、 功能可调等特点, 已被证明具有成为癌症诊疗药物负载平台的巨大潜力. 本文介绍了将诊疗药物负载到MOFs中的策略, 并综合评述了在磁共振成像、 计算机断层扫描成像、 正电子发射断层扫描成像、 光学成像和光声成像等多种成像技术指导下, MOFs作为癌症诊断和治疗平台的发展概况. 此外, 还讨论了MOFs在癌症诊疗和临床转化方面当前面临的挑战和发展前景.     

金属有机框架抗菌材料的研究进展

细菌耐药问题已经成为了中国乃至全球的重大公共健康威胁,设计合成新型抗菌材料以减少抗生素依赖成为当前化学化工、材料和生物医学领域中的重要研究课题.金属有机框架(Metal-organic frameworks, MOFs)材料是由有机配体和金属离子或团簇通过配位键自组装形成的多孔晶态材料,在气体吸附与分离、传感和催化等领域都扮演着重要角色.为了寻求更好应对细菌威胁的方式方法,国内外研究者们纷纷构建出不同结构的MOFs材料,并将其应用于抗菌领域.本综述从细菌耐药性的产生和MOFs抗菌机理等方面出发,分类概述了不同金属中心和配体MOFs材料、MOFs包覆金属纳米粒子材料和药物缓释MOFs材料等在抗菌、促进伤口愈合等方面的应用,归纳概括了MOFs材料在抗菌领域应用中仍需解决的科学问题,并对该领域的发展趋势进行了展望.     

金属有机骨架复合材料生物传感器检测肿瘤标志物的应用进展

生物传感器是传统肿瘤标志物检测方法的有效替代方法,而基于金属有机骨架(MOF)复合材料的生物传感器在肿瘤标志物检测方面具有速度快、灵敏度高、检出限低、成本低等优点.综述了MOF及其复合材料的分类,介绍了基于MOF复合材料的生物传感器在检测肿瘤标志物方面的应用进展,并对基于MOF复合材料的生物传感器未来发展趋势进行了展望...     

水滑石(LDHs)及其衍生物在生物医药领域的研究进展

生物医学涉及到人类健康相关的多个领域:临床医疗、公共卫生、医药研发等多个方面.其中在医药研发领域,基于插层结构的纳米药物载体的研发已经成为重要发展方向之一.水滑石(LDHs)及其衍生物具有成本低、合成简单、载药高效、细胞膜透过率高、生物相容性好、易降解等优点,在生物医药领域得到了广泛关注.本文主要介绍了LDHs及其衍生物的制备方法,以及在抗菌治疗、生物成像和肿瘤治疗等方面的应用.此外,还简述了LDHs材料的规模化生产方法和现状,进一步分析了LDHs的实际应用前景.最后,对LDHs材料在生物医药领域的未来发展方向进行了展望.     

金属有机框架材料在光催化中的应用

金属-有机框架材料(metal-organic frameworks,MOFs)是一类基于金属离子与有机配体组装而成的配位多孔材料,具有高比表面积、多活性位点、结构可剪裁、易功能化等特征.相当一部分MOFs能够表现出类半导体的行为,其有序结构不利于光生电子-空穴复合中心的产生,同时其多孔特性更是便于光生载流子的快速/高效利用.因此,近年来MOFs材料在光催化领域受到越来越广泛的关注与研究.本文从光催化反应类型出发,包括光催化染料降解、光催化有机物转化、光催化裂解水产氢、光催化水氧化、光催化二氧化碳还原反应等,总结了近年来MOFs及其复合催化剂设计合成及在光催化领域的应用研究进展,同时简要介绍了部分MOF衍生材料在光催化领域的应用,并对MOFs材料在光催化领域的应用前景进行了展望.     

金属-有机框架材料在液相催化化学制氢中的研究进展

金属-有机框架(MOFs)材料是由金属簇节点或金属离子与有机配体连接而成的典型的无机-有机杂合物, 作为一类新兴的无机多孔晶态材料, MOFs因具有高度有序的多孔性、 结构可裁剪性、 高比表面积及灵活多变的骨架类型等优点而在工业合成、 能源开发、 环境治理和生物制药等领域展现出广阔的应用前景. 本文从氢能源的开发利用出发, 总结了近年来MOFs基纳米复合材料在催化化学制氢方面的研究进展. 讨论了常见的含氢量高的化学储氢材料, 包括氨硼烷、 甲酸和水合肼等; 催化材料主要有单一MOFs、 MOF基贵金属和非贵金属复合材料及MOF基衍生材料等. 最后, 对MOF基复合材料在液相催化化学储氢中的应用前景进行了展望.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.