Lead identification of 1,4-benzoxazines as anti-tuberculosis agents

1,4-苯并嗪作为抗结核药物的初步鉴定

• 批准号: 7146363
• 负责人: Scott G. Franzblau
• 金额: $ 23.25万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-20 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7146363
• 关键词: binding proteins; cell line; cytotoxicity; heterocyclic polycyclic compound; lead; library; macrophage; pharmacokinetics; protein binding; tuberculosis

DESCRIPTION (provided by applicant): New classes of anti-tuberculosis agents are needed to combat resistance to existing agents and to shorten the duration of therapy. This revised proposal explores the potential of 1,4 benzoxazines as anti-tuberculosis agents. A screening program identified six 1,4 benzoxazines with sub-microgram/ml MICs against M. tuberculosis and no detectable mammalian cell cytotoxicity with resulting selectivity indices of >100. Several structure-activity relationships were also revealed. These compounds were also active at low microgram/ml levels against M. tuberculosis in murine macrophages. Polar surface area calculations predict good absorption when administered orally and preliminary results suggest low toxicity in mice upon oral administration. New preliminary data suggests a lack of formation of glutathione adducts, activity against drug-resistant strains and (via expression profiling) a mechanism of action not shared by existing agents. In order to identify a lead compound from this class a focused library of approximately one hundred and fifty new 1,4 benzoxazines will be synthesized using a strategy that covers substitution at all possible position with minimal synthetic effort. Both classical and parallel synthesis will be used to produce 4-dihydro-2H-1,4-benzoxazines via reaction of polycarbonyl compounds (2,4 diketo acids and tetraketones) with oaminophenols. Additional analogs will be produced by chlorination and then reaction with N, O- and S nucleophilic reagents resulting in the production of 3-vinyl-2H-1,4 benzoxazines. These compounds are predicted to be drug-like and orally available based on "Lipinski rules" in addition to low polar surface area and numbers of rotatable bonds. All compounds will be assessed for activity against both logarithmic phase M. tuberculosis as well as against non-replicating M. tuberculosis using low oxygen incubation. All compounds will also be assessed for toxicity to a mammalian cell line. Potent (MIC<1 ug/ml) and selective (selectivity indices>100) compounds will be assessed for anti-TB activity against drug-resistant strains, and activity in murine macrophages. Active compounds will be assessed for stability in the presence of human microsomes, P-450 mediated cytotoxicity and protein binding. Compounds with the best in vitro profiles will be evaluated for pharmacokinetic properties in mice including oral bioavailability and lung tissue concentrations. The best candidates will be assessed for comparative passage through CACO-2 cells vs. a bovine brain epithelial cell line, as well as for spectrum of activity and frequency of resistance. Mechanism of action will be investigated by transcriptional profiling as well as identification of gene mutations in resistant mutants using microarray-based screening and sequencing. This exploratory R21 proposal is expected to determine the potential of this class to yield a clinically useful agent for tuberculosis and to provide a lead compound(s) for further optimization and pre-clinical development.

描述（由申请人提供）：需要新的抗结核药物来对抗现有药物的抵抗力并缩短治疗持续时间。这项修订的建议探讨了1,4苯唑嗪作为抗结核药的潜力。一项筛选程序确定了六个1,4苯唑嗪，其亚微图/ML麦克风针对结核分枝杆菌，没有可检测的哺乳动物细胞毒性，因此选择性指数> 100> 100。还揭示了几种结构活动关系。这些化合物在低微克/mL水平上也与鼠巨噬细胞中的结核分枝杆菌相比活跃。极性表面积计算预测口服给药时的吸收良好，初步结果表明口服时小鼠的毒性低。新的初步数据表明，缺乏谷胱甘肽加合物的形成，对药物抗药性菌株的活性以及（通过表达分析）一种作用机理，一种无法共享的作用机理。为了确定该类A类的铅化合物，将使用大约150个新的1,4苯唑嗪的铅库使用策略来合成，该策略以最小的合成工作涵盖所有可能位置的替代位置。经典和平行的合成将用于通过聚碳苯甲化合物（2,4二烷酸酸和四甲酸酯）与肥皂酚的反应产生4-二氢-2H-1,4-苯并嗪。额外的类似物将通过氯化产生，然后与N，O-和S亲核试剂反应，从而产生3-乙烯基-2H-1,4苯唑嗪的产生。除了低极性表面积和可旋转键的数量外，这些化合物被预计将基于“ Lipinski规则”，基于“ Lipinski规则”。所有化合物都将均可评估与对数的结核病相对的活性，以及​​使用低氧气孵育的非重复结核分枝杆菌的活性。所有化合物还将评估对哺乳动物细胞系的毒性。将评估有效（MIC <1 ug/ml）和选择性（选择性指数> 100）化合物，以评估针对药物抗药性菌株的抗TB活性以及在鼠巨噬细胞中的活性。在人类微粒体，P-450介导的细胞毒性和蛋白质结合的情况下，将评估活性化合物的稳定性。将评估具有口服生物利用度和肺组织浓度在内的小鼠的药代动力学特性的最佳化合物。最好通过CACO-2细胞与牛脑上皮细胞系以及活性和耐药性频谱评估最佳候选者。通过基于微阵列的筛选和测序，将通过转录分析以及抗性突变体中基因突变的鉴定来研究作用机理。预计该探索性R21提案将确定该类别的潜力产生临床上有用的结核病药物，并提供铅化合物，以进一步优化和临床前发育。