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: 7295692
• 负责人: Scott G. Franzblau
• 金额: $ 18.81万
• 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 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7295692
• 关键词: Acids; Antitubercular Agents; Area; Benzoxazines; Biological Availability; Blood - brain barrier anatomy; Bos taurus; Brain; Caco-2 Cells; Cattle; Cell Line; Chemicals; Class; Data; Development; Drug Kinetics; Drug resistance; Epithelial Cells; Frequencies; Gene Mutation; Glutathione; Human; In Vitro; Lead; Libraries; Mammalian Cell; Mediating; Metabolic; Microsomes; Molecular Profiling; Mus; Mycobacterium tuberculosis; Numbers; Object Attachment; Oral; Oral Administration; Oxygen; Pharmaceutical Preparations; Phase; Phenotype; Positioning Attribute; Production; Property; Protein Binding; Reaction; Reagent; Resistance; Screening procedure; Structure of parenchyma of lung; Structure-Activity Relationship; Surface; Toxic effect; Tuberculosis; absorption; adduct; analog; base; chlorination; comparative; cytotoxicity; indexing; intestinal epithelium; macrophage; mutant; pre-clinical; programs; therapy duration

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对现有药物的耐药性，并缩短治疗时间。这项修订后的提案探讨了1，4苯并恶嗪作为抗结核药物的潜力。筛选程序鉴定出6种1，4苯并恶嗪对结核分枝杆菌的最低抑菌浓度为亚微克/毫升，没有检测到哺乳动物细胞的细胞毒性，其选择性指数为&gt；100。还揭示了几种构效关系。这些化合物对小鼠巨噬细胞中的结核分枝杆菌也具有低水平的抗结核活性。极表面积计算预测口服给药时吸收良好，初步结果表明口服给药对小鼠的毒性较低。新的初步数据表明，缺乏谷胱甘肽加合物的形成，对耐药菌株的活性，以及(通过表达谱)现有药物不具有的作用机制。为了从这类化合物中识别出一种先导化合物，将使用一种策略来合成大约150个新的1，4苯并恶嗪的重点文库，该策略包括以最小的合成工作量在所有可能的位置进行取代。通过多酮化合物(2，4二酮酸和四酮)与邻氨基苯酚的反应合成4-二氢-2H-1，4-苯并恶嗪。更多的类似物将通过氯化产生，然后与N，O-和S亲核试剂反应，生成3-乙烯-2H-1，4苯并恶嗪。除了低极性表面积和可旋转键的数量外，根据“利平斯基规则”，这些化合物预计将是类药物和口服可用化合物。将使用低氧培养法评估所有化合物对对数期结核分枝杆菌和非复制型结核分枝杆菌的活性。所有化合物还将被评估对哺乳动物细胞系的毒性。强效(MIC&lt；1ug/ml)和选择性(选择性指数&gt；100)化合物将被评估对耐药菌株的抗结核活性，以及在小鼠巨噬细胞中的活性。活性化合物将在人类微体存在、P-450介导的细胞毒性和蛋白质结合的情况下进行稳定性评估。具有最佳体外曲线的化合物将被评估在小鼠身上的药代动力学特性，包括口服生物利用度和肺组织浓度。最好的候选者将被评估通过CACO-2细胞与牛脑上皮细胞系的比较传代，以及活动谱和耐药频率。作用机制将通过转录图谱以及利用基于微阵列的筛选和测序鉴定耐药突变体的基因突变来研究。这一探索性的R21提案有望确定这类药物产生临床有用结核病药物的潜力，并为进一步的优化和临床前开发提供先导化合物(S)。