Development of novel proteins synthesis inhibitors for MDR tuberculosis

描述(申请人提供)：由于最近多重耐药生物的增加，我们调查了开发现有验证的天然产品支架以生产具有更强活性的新的半合成抗生素的可能性。我们专注于低分子氨基环磷胆醇壮观霉素，因为它：一直在研究中；具有安全的药理特性；靶标核糖体结合位点在细菌病原体中高度保守，但与其他氨基糖苷类药物分离；在无细胞分析中有效；结构易于处理，允许使用基于结构的药物设计技术进行先进的合成修饰；由于细菌渗透和吸收问题，限制了临床应用。产生了几个新的类似物，并对敏感和抗药性细菌的小组进行了筛选，以寻找具有更好的抗菌活性的化合物。从这些系列中，我们发现了一类新型的抗结核药物--壮观酰胺类药物。我们最有效的化合物显示：出色的抗结核活性；靶向抑制结核分枝杆菌的蛋白质合成；与现有抗结核药物，包括那些活跃在核糖体上的药物(链霉素、卡那霉素、卷曲霉素和利奈唑胺)没有交叉耐药性；良好的药代动力学特性，包括出色的血清和微球稳定性；以及体内抗结核活性。初步结果表明，壮观酰胺活性的提高部分是由于结核杆菌对壮观的摄取。我们相信，壮观酰胺是一种可用于治疗耐药结核分支杆菌感染的新化学类型的重要发现，我们计划通过这项合作研究提案在三个研究目标上扩大和进一步开发：(I)化合物开发-计算机辅助药物设计将用于迭代药物开发周期，以设计和合成具有高抗结核效力的壮观酰胺；(Ii)作用模式-分子技术，包括全基因组测序，将用于确定壮观胺抗结核活性和吸收增强的遗传基础；将使用生化分析来评估铅化合物在目标水平上的作用模式，以确保在我们的铅开发周期中取得进展的化合物仍然有效和选择性地抑制细菌蛋白质合成；(Iii)铅开发和表征-合成的化合物将经过三个阶段的测试，其中包括微生物评估、药代动力学测试、毒理学和体内疗效实验。在每个阶段之后，这些数据将用于目标1的进一步设计和合成周期，并将选择最佳化合物进入下一阶段，以便从这项研究中产生可行的、具有良好特征的候选药物。在这项研究中，我们建议开发一类新的蛋白质合成抑制剂来治疗有问题的耐多药结核病感染。这项研究中发现的化合物也可能治疗其他耐药细菌疾病。

DESCRIPTION (provided by applicant): Due to the recent rise in multi-drug resistant organisms, we investigated the potential for developing existing validated natural product scaffolds to produce new semi synthetic antibiotics with more potent activity. We focused on the low molecular weight aminocyclitol spectinomycin as it: has been under studied; has a safe pharmacological profile; targets a ribosomal binding site highly conserved across bacterial pathogens, but separate from other aminoglycosides; is potent in cell free assays; is structurally tractable, allowing for advanced synthetic modification using structure based drug design techniques; has limited clinical use due to bacterial penetration and uptake issues. Several novel analogs were generated and screened against panels of both sensitive and drug resistant bacteria to find compounds with improved anti-bacterial activity. From these series, we discovered a novel class of anti-tuberculosis agents, the spectinamides. The most potent of our compounds demonstrate: excellent anti-tuberculosis activity; on target inhibition of protein synthesis in M. tuberculosis; no cross resistance to existing anti-tuberculosis drugs including those active at the ribosome (Streptomycin, Kanamycin, Capreomycin and Linezolid); good pharmacokinetic profiles including excellent serum and microsomal stability; and anti- tuberculosis activity in vivo. Preliminary results show that improved activity of spectinamides results in part from superior uptake into TB bacilli. We believe the spectinamides are an important discovery of a new chemotype that can be used for the treatment of drug resistant M. tuberculosis infections which we plan to expand and further develop through this collaborative research proposal in three research aims: (i) Compound development - computer aided drug design will be used in an iterative drug development cycle for the design and synthesis of spectinamides with high anti-tubercular potency; (ii) Mode of action - Molecular techniques, including whole genome sequencing, will be used to determine the genetic basis for the improved activity and uptake of the spectinamides against TB; biochemical assays will be used evaluate mode of action of lead compounds at the target level to ensure compounds that progress in our lead development cycle remain potent and selective for inhibition of bacterial protein synthesis; (iii) Lead development and characterization - Compounds synthesized will progress through three stages of tests that include microbial assessment, pharmacokinetic testing, toxicologic and in vivo efficacy experiments. After each stage, the data will be used in further design and synthesis cycles in aim 1 and the best compounds will be selected to move on to the next stage such that viable, well characterized drug candidates will emerge from this study. In this study we propose to develop a novel class of protein synthesis inhibitors to treat problematic multi-drug resistant tuberculosis infections. Compounds discovered in this study may also have the potential to treat other drug resistant bacterial diseases.