Design of chiral Co(<scp>ii</scp>)-MOFs and their application in environmental remediation and waste water treatment
作者:Sudeshna Bhattacharya、Sukhen Bala、Raju Mondal
DOI:10.1039/c5ra26154f
日期:——
The present work reports the construction of new Co-MOFs based on an amide based bispyrazole ligand and different carboxylic acids with potential applications in the sphere of CO2 adsorption and photocatalytic wastewatertreatment. Four multifunctional MOFs, with a wide variety of dimensionality, porosity and surface characteristics were exploited for this purpose. The unique bis-bidentate nature
Active substances for the treatment, diagnosis and prophylaxis of diseases in which abnormal protein structures occur
申请人:Schrader Thomas
公开号:US20050239808A1
公开(公告)日:2005-10-27
The invention on hand refers to diseases associated with abnormal protein structures, including Alzheimer's disease, Creutzfeldt-Jakob's disease, BSE and other prion-associated diseases. It is the task of the invention on hand to provide new active agents preventing the formation of amyloid plaques and to dissolve existing plaques, such agents being convenient for therapy, diagnosis and prophylaxis of diseases that are associated with abnormal protein structures. This task is performed in terms of the current invention by heterocyclic or aromatic agents with a rigid structure and a donor-acceptor-donor pattern (DAD), the latter being formed by donors and acceptors of hydrogen bridge linkages which comply with the β-sheet structure of the peptide or protein and thus fit as binding partners. The heterocyclic or aromatic agents are available at least as dimers. They recognise peptides and proteins with a β-sheet structure, form stable complexes with them and inhibit their aggregation to β-amyloid plaques. Furthermore, the new active agents are able to dissolve β-amyloid plaques that already exist. Another task of the current invention is to provide methods for the synthesis of said heterocyclic or aromatic compounds.
A general concept for the stabilization of β-sheetsby designed artificial ligands is introduced. The ligands have twokey features: they contain acylated 3-aminopyrazoles with a DAD hydrogenbond donor and acceptor pattern, and they were synthesized as oligomersin order to multiply their hydrogen bond interactions with peptidesin the β-sheet conformation. Dimeric aminopyrazoles wereaccessible by reaction of the N1-Boc-protectedaminopyrazole derivative 1 with severalacid dichlorides followed by a standard deprotection procedure withtrifluoroacetic acid. For the oligomers, N1-PMBprotection of new pyrazole amino acids followed by an iterativeextension protocol with peptide coupling using PyClop or Mukaiyama’sreagent led to the target compounds. All protecting groups weresubsequently removed in a final deprotection step with warm trifluoroaceticacid. Two dimeric key compounds 3b and 3f were examined by NMR at various temperatures,in NOESY experiments as well as by X-ray crystallography in orderto elucidate their conformational preference in solution and thesolid state. The emerging picture was the same for all methods: bothligands adopt a flat conformation with a high degree of pre-orientationand the correct DAD pattern for optimal interaction with peptidesin their extended conformation. Aggregation assays with the Prionprotein and the Alzheimer’s peptide Aβ (1-40)show highly promising results for some of the dimeric and oligomericligands at very low concentrations.
本文介绍了利用设计的人工配体稳定δ-片材的一般概念。这些配体有两个主要特征:它们含有酰化的 3-氨基吡唑,具有 DAD 氢键供体和受体模式;它们被合成为低聚物,以增加它们与δ-片构象中的肽的氢键相互作用。二聚氨基吡唑可通过 N1-Boc 保护的氨基吡唑衍生物 1 与几种二氯酸反应,然后用三氟乙酸进行标准脱保护处理而获得。对于低聚物,对新的吡唑氨基酸进行 N1-PMB 保护,然后使用 PyClop 或 Mukaiyama 试剂与肽偶联进行迭代扩展,最终得到目标化合物。随后,所有的保护基团都在最后一步用温三氟乙酸进行脱保护。对两个二聚关键化合物 3b 和 3f 进行了不同温度下的核磁共振、NOESY 实验和 X 射线晶体学研究,以阐明它们在溶液和固体状态下的构象偏好。所有方法得出的结果都是一样的:两种配体都采用具有高度预取向性的扁平构象和正确的 DAD 模式,以便与扩展构象中的肽发生最佳相互作用。用朊病毒蛋白和阿尔茨海默氏症肽 Aβ (1-40) 进行的聚合试验表明,一些二聚体和寡聚体配体在极低浓度下就能产生很好的效果。