A structure-activity relationship (SAR) study of NOSO-95179, a nonapeptide from the Odilorhabdin class of antibacterials, was performed by systematic variations of amino acids in positions 2 and 5 of the peptide. A series of non-proteinogenic amino acids was synthesized in high enantiomeric purity from Williams' chiral diphenyloxazinone by highly diastereoselective alkylation or by aldol-type reaction. NOSO-95179 analogues for SAR studies were prepared using solid-phase peptide synthesis. Inhibition of bacterial translation by each of the synthesized Odilorhabdin analogues was measured using an in vitro test. For the most efficient analogues, antibacterial efficacy was measured against two wild-type Enterobacteriaceae (Escherichia coli and Klebsiella pneumoniae) and against an efflux defective E. coli strain (ΔtolC) to evaluate the impact of efflux on the antibacterial activity.

中文翻译：

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构效关系研究抑制新型Odilorhabdins类似物的细菌翻译。

通过对肽第2位和第5位的氨基酸进行系统性变异，对NOSO-95179（一种来自Odilorhabdin类抗菌剂的九肽）进行了结构活性关系（SAR）研究。通过高度非对映选择性烷基化或醛醇型反应，从威廉姆斯的手性二苯基恶嗪酮合成了一系列非对映体高纯度氨基酸。使用固相肽合成方法制备了用于SAR研究的NOSO-95179类似物。使用体外测试来测量每种合成的奥地洛滨类似物对细菌翻译的抑制作用。对于最有效的类似物，测定了对两种野生型肠杆菌科细菌（大肠杆菌和肺炎克雷伯菌）的抗菌效果以及对流出缺陷型大肠杆菌的抗菌效果。