FOCUSED PARALLEL SYNTHESIS OF DICATION ANTIFUNGAL AGENTS

所提出的研究源于我们之前对阳离子分子抗真菌活性的研究。这些初步的体外研究表明，先导化合物对白色念珠菌和新生隐球菌具抑制和杀菌作用，其MIC80S为0.09g/mg，MFCs为0.10g/ml。我们的研究还表明，这些化合物对烟曲霉、茄病镰刀菌、除白色念珠菌以外的念珠菌以及对氟康唑耐药的白色念珠菌和新生念珠菌都有活性。一家外部实验室证实了我们的体外数据，并显示先导化合物对烟曲霉菌的IC50值小于0.0050微克/毫升，与HeLa细胞相比，选择性指数超过2000。更重要的是，外部实验室证明，其中一种化合物在念珠菌病小鼠存活模型中的活性与氟康唑相同。上述发现以及我们对阳离子化合物的毒理学和药理学研究清楚地表明，这些分子在抗真菌方面具有很大的潜力。目前的提议将扩大这些初步研究，每年利用组合化学技术合成2400多个相关分子，并在体外模型中测试这些分子对白色念珠菌和烟曲霉菌的活性以及对THP-1细胞(人单核细胞)的毒性。由于抗真菌活性的确切机制尚不清楚，而且先前的结果表明，多种作用模式可能有助于它们的抗真菌活性，因此这些化合物将针对有机体而不是特定的目标进行筛选。抗真菌数据将受到详细的QSAR和建模研究的影响，这些结果将用于指导拟议文库的扩展、新文库的开发或相关分子的一小部分的树脂合成。最后，选定的分子将在真菌感染的动物模型中进行测试。这项提案汇集了一批经验丰富的研究人员，他们在抗菌研究方面进行了七年多的成功合作。利用组合化学方法建立有针对性的文库，结合高通量筛选和数据管理，将优化该小组实现该项目目标的机会；新抗真菌药物的发现。

The proposed studies stem from our previous research on the antifungal activity of dicationic molecules. These initial in vitro studies on over 300 dication molecules showed that leading compounds were both inhibitory and fungicidal against Candida albicans and Cryptococcus neoformans with MIC80S of <0.09 g/mg and MFCs of 0.10 g/ml against both organisms. Our studies also demonstrated that the compounds were active against Aspergillus fumigatus, Fusarium solani, Candida species other than C. albicans and fluconazole-resistant strains of C. albicans and C. neoformans. An outside laboratory confirmed our in vitro data and also showed that leading compounds against A. fumigatus had IC50 values that were less than 0.0050 mu g/ml and selectivity indices, when compared to HeLa cell, over 2000. More importantly, the outside laboratory demonstrated that one of the compounds was equally as active as fluconazole in a mouse survival model of candidiasis. The above findings along with our studies on the toxicology and pharmacology of dicationic compounds clearly show that these molecules have great potential as antifungal agents. The current proposal will expand these initial studies by synthesizing over 2,400 related molecules per year utilizing combinatorial chemistry technology and testing these molecules in an in vitro model for activity against C. albicans and A. fumigatus and toxcity in THP-1 cell (human monocytes). Since the exact mechanism of antifungal activity is not known, and previous results indicated that more than one mode of action may contribute to their antifungal activity the compounds will be screened against the organism rather than a specific target. The antifungal data will be subjected to detailed QSAR and modeling studies and these results will be used to guide either the expansion of proposed libraries, the development of new libraries, or off resin synthesis of a small subset of related molecules. Finally, selected molecules will be tested in animal models of fungal infections. This proposal brings together a seasoned group of investigators with over seven years of successful collaboration on antimicrobial research. Utilizing the combinatorial chemistry methodology to build focused libraries coupled with high-throughput screening and data management will optimize the groups chances of achieving the goal of this project; the discovery of new antifungal agents.