Pyrimido[4,5-c]pyridazines. 3. Preferential formation of 8-amino-1H-pyrimido[4,5-c]-1,2-diazepin-6(7H)-ones by cyclizations with .alpha.,.gamma.-dioxo esters
This invention provides pyrimido (4,5-c)pyridazines, process for their preparation, veterinary compositions containing them and the preparation of such compositions. These pyrimido (4,5-c)pyridazines are useful in the treatment of coccidiosis.
The present invention provides pyrimido(4,5-c)pyridazines, to methods for preparing them, formulations containing them and the preparation of such formulation and the use of such compounds in human therapy. These pyrimido(4,5-c)pyridazines of this invention are useful due to their activity as inhibitors of dihydropteroic and biosynthesis.
molecular architectures with high potential for various applications in supramolecular chemistry. Their covalent synthesis, however, is often tedious and the structures obtained lack structural responsiveness beyond the limited conformational flexibility of the scaffold. Herein we present a proof-of-concept study on the design, synthesis, assembly, and transformations of a novelsupramolecular construct─a
分子镊子是开放式、具有空腔的 U 形分子结构,在超分子化学的各种应用中具有很高的潜力。然而,它们的共价合成通常是乏味的,并且获得的结构缺乏结构响应性,超出了支架有限的构象灵活性。在此,我们对一种新型超分子结构(一种完全非共价分子镊子)的设计、合成、组装和转化进行了概念验证研究。超分子镊子由一组四个构件组装而成,由两个相同的分子角条和两个扁平的芳香延伸翼组成,仅使用氢键。手性辅助聚集过程用于使用对映体纯双环角棒确保支架弯曲方向性。为了解决与平衡从循环聚集体中自互补角条的强合作自恋自分类向分子镊子中的综合自分类转变相关的挑战,应用了合理的去对称化策略。动态超分子镊子已显示出丰富的超分子化学,允许聚合拓扑结构的刺激响应变化和溶剂响应超分子聚合。
Toxoflavins and Deazaflavins as the First Reported Selective Small Molecule Inhibitors of Tyrosyl-DNA Phosphodiesterase II
作者:Ali Raoof、Paul Depledge、Niall M. Hamilton、Nicola S. Hamilton、James R. Hitchin、Gemma V. Hopkins、Allan M. Jordan、Laura A. Maguire、Alison E. McGonagle、Daniel P. Mould、Mathew Rushbrooke、Helen F. Small、Kate M. Smith、Graeme J. Thomson、Fabrice Turlais、Ian D. Waddell、Bohdan Waszkowycz、Amanda J. Watson、Donald J. Ogilvie
DOI:10.1021/jm400568p
日期:2013.8.22
The recently discovered enzyme tyrosyl-DNA phosphodiesterase 2 (TDP2) has been implicated in the topoisomerase-mediated repair of DNA damage. In the clinical setting, it has been hypothesized that TDP2 may mediate drug resistance to topoisomerase II (topo II) inhibition by etoposide. Therefore, selective pharmacological inhibition of TDP2 is proposed as a novel approach to overcome intrinsic or acquired resistance to topo II-targeted drug therapy. Following a high-throughput screening (HTS) campaign, toxoflavins and deazaflavins were identified as the first reported sub-micromolar and selective inhibitors of this enzyme. Toxoflavin derivatives appeared to exhibit a clear structure-activity relationship (SAP.) for TDP2 enzymatic inhibition. However, we observed a key redox liability of this series, and this, alongside early in vitro drug metabolism and pharmacokinetics (DMPK) issues, precluded further exploration. The deazaflavins were developed from a singleton HTS hit. This series showed distinct SAR and did not display redox activity; however low cell permeability proved to be a challenge.
Pyrimido[4,5-c]pyridazines. 5. Summary of cyclizations with vicinally functionalized reagents and studies of the reductive behavior of the ring system