CHIR-090 is a very potent and selective LpxC inhibitor with antibiotic activity.

LpxC:4.0 nM. (Ki)

CHIR-090是一种针对超好热菌Aquifex aeolicus中LpxC去乙酰酶的强效、缓慢、紧密结合抑制剂，具有出色的对P. aeruginosa和E. coli的抗生素活性，通过圆盘扩散实验评估。CHIR-090还是对大肠杆菌Escherichia coli LpxC的两步缓慢、紧密结合抑制剂，其Ki值为4 nM。在低纳摩尔水平下，CHIR-090能抑制多种革兰氏阴性病原体的LpxC同源体，包括铜绿假单胞菌Pseudomonas aeruginosa、脑膜炎奈瑟菌Neisseria meningitidis和幽门螺杆菌Helicobacter pylori。相反，CHIR-090对来自根瘤菌Rhizobium leguminosarum的LpxC是一个相对较弱的竞争性和常规抑制剂（缺乏缓慢、紧密结合动力学），其Ki值为340 nM，这是一种对该化合物有抗性的革兰氏阴性植物共生体。当用R. leguminosarum的lpxC基因替换大肠杆菌染色体上的lpxC基因时，构建的E. coli对CHIR-090的抗性高达100 μg/mL，是野生型E. coli最小抑制浓度的400倍。CHIR-090是Aquifex aeolicus LpxC的一种非常强效的慢性、紧密结合抑制剂，其序列与E. coli LpxC有31%的同源性。CHIR-090对E. coli和P. aeruginosa表现出与环丙沙星相当的显著抗生素活性，通过圆盘扩散实验评估。

CHIR-090是一种针对大肠杆菌(E. coli)的强效抗生素，具有在低nM范围内抑制大肠杆菌LpxC的体外活性。未经化学诱变的大肠杆菌W3110菌株在含有1μg/mL CHIR-090的条件下未观察到耐药菌落。大肠杆菌W3110的一株能在含有1至10μg/mL CHIR-090的LB琼脂平板上生长，这是我们条件下野生型大肠杆菌W3110的最低抑菌浓度(MIC)0.25μg/mL的4至40倍。在1μg/mL CHIR-090存在下，W3110RL的倍增时间为40分钟，与无抑制剂的野生型的生长率完全相同。在含有1μg/mL CHIR-090的情况下，野生型细胞在大约2小时后停止生长[1]。

Disk diffusion is conducted, except that 10 μg of each antibiotic compound is used per filter. Growth in liquid medium in the presence of CHIR-090 is evaluated as follows: cells from overnight cultures are inoculated into 50 mL portions of LB broth at an A600 of 0.02 and grown with shaking at 30°C. When the A600 reaches 0.15, parallel cultures are treated with either 6 μL of 500 μg/mL CHIR-090 in DMSO or 6 μL of DMSO. To assess cumulative growth, cultures are maintained in log phase growth by 10-fold dilution into pre-warmed medium, containing the same concentrations of DMSO or DMSO/CHIR-090, whenever the A600 reaches 0.4. The minimal inhibitory concentration is defined as the lowest antibiotic concentration at which no measurable bacterial growth is observed in LB medium containing 1% DMSO (v/v), when inoculated at a starting density of A600=0.01. Cultures are incubated with shaking for 24 h at 30°C in the presence of CHIR-090. Experiments are performed in triplicate[1].