ABSTRACTPeptide deformylase (PDF), a metallohydrolase essential for bacterial growth, is an attractive target for use in the discovery of novel antibiotics. Focused chelator-based chemical libraries were constructed and screened for inhibition of enzymatic activity, inhibition ofStaphylococcus aureusgrowth, and cytotoxicity. Positive compounds were selected based on the results of all three assays. VRC3375 [N-hydroxy-3-R-butyl-3-(2-S-(tert-butoxycarbonyl)-pyrrolidin-1-ylcarbonyl)propionamide] was identified as having the most favorable properties through an integrated combinatorial and medicinal chemistry effort. This compound is a potent PDF inhibitor with aKiof 0.24 nM against theEscherichia coliNi2+enzyme, possesses activity against gram-positive and gram-negative bacterial pathogens, and has a low cytotoxicity. Mechanistic experiments demonstrate that the compound inhibits bacterial growth through PDF inhibition. Pharmacokinetic studies of this drug in mice indicate that VRC3375 is orally bioavailable and rapidly distributed among various tissues. VRC3375 has in vivo activity againstS. aureusin a murine septicemia model, with 50% effective doses of 32, 17, and 21 mg/kg of body weight after dosing by intravenous (i.v.), subcutaneous (s.c.), and oral (p.o.) administration, respectively. In murine single-dose toxicity studies, no adverse effects were observed after dosing with more than 400 mg of VRC3375 per kg by i.v., p.o., or s.c. administration. The in vivo efficacy and low toxicity of VRC3375 suggest the potential for developing this class of compounds to be used in future antibacterial drugs.
摘要肽变形酶(PDF)是细菌生长所必需的一种金属水解酶,是发现新型抗生素的一个有吸引力的目标。我们构建了基于螯合剂的化学库,并对其酶活性抑制、金黄色葡萄球菌生长抑制和细胞毒性进行了筛选。根据所有三项检测的结果筛选出阳性化合物。VRC3375 [N-羟基-3-R-丁基-3-(2-S-(叔丁氧羰基)-吡咯烷-1-基羰基)丙酰胺] 通过组合化学和药物化学的综合努力被鉴定为具有最有利的特性。该化合物是一种强效的 PDF 抑制剂,对大肠杆菌 Ni2+ 酶的 Kio 值为 0.24 nM,对革兰氏阳性和革兰氏阴性细菌病原体均有活性,而且细胞毒性低。机理实验证明,该化合物通过 PDF 抑制作用抑制细菌生长。该药物在小鼠体内的药代动力学研究表明,VRC3375 具有口服生物利用度,并能迅速分布于各种组织。在小鼠败血症模型中,VRC3375 对金黄色葡萄球菌具有体内活性,静脉注射、皮下注射和口服给药的 50%有效剂量分别为 32、17 和 21 毫克/千克体重。在小鼠单剂量毒性研究中,通过静脉注射、皮下注射或口服给药,每公斤剂量超过 400 毫克 VRC3375 后,未观察到任何不良反应。VRC3375 的体内疗效和低毒性表明,这类化合物具有开发潜力,可用于未来的抗菌药物中。