In Gram-negative bacteria, efflux pumps are able to prevent effective cellular concentrations from being achieved for a number of antibiotics. Small molecule adjuvants that act as efflux pump inhibitors (EPIs) have the potential to reinvigorate existing antibiotics that are currently ineffective due to efflux mechanisms. Through a combination of rigorous experimental screening and in silico virtual screening, we recently identified novel classes of EPIs that interact with the membrane fusion protein AcrA, a critical component of the AcrAB-TolC efflux pump in Escherichia coli. Herein, we present initial optimization efforts and structure–activity relationships around one of those previously described hits, NSC 60339 (1). From these efforts we identified two compounds, SLUPP-225 (17h) and SLUPP-417 (17o), which demonstrate favorable properties as potential EPIs in E. coli cells including the ability to penetrate the outer membrane, improved inhibition of efflux relative to 1, and potentiation of the activity of novobiocin and erythromycin.

中文翻译：

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新型化合物的鉴定和结构-活性关系增强了大肠杆菌中抗生素的活性

在革兰氏阴性细菌中，外排泵能够防止多种抗生素达到有效的细胞浓度。充当外排泵抑制剂（EPI）的小分子佐剂有可能使现有的由于外排机制无效的抗生素恢复活力。通过严格的实验筛选和计算机虚拟筛选的组合，我们最近确定了与膜融合蛋白AcrA相互作用的新型EPI，AcrA是大肠杆菌中AcrAB-TolC外排泵的关键组件。在本文中，我们介绍了围绕先前提到的命中之一NSC 60339（1）的初步优化工作以及结构与活性之间的关系。通过这些努力，我们确定了两种化合物，SLUPP - 225（17小时）和SLUPP - 417（170），它表现出良好的特性，如潜在环境绩效指标大肠杆菌细胞，包括渗透外膜的能力，改进的相对流出的抑制作用1新生霉素的活性的，和增强和红霉素。