New N -4 piperazinyl derivatives of norfloxacin: design, synthesis, and correlation of calculated physicochemical parameters with antibacterial activity
作者:Gamal El-Din ABUO-RAHMA、Samar ABBAS、Mai SHOMAN、Ebtihal SAMIR、Rehab ABDEL-BAKY
DOI:10.3906/kim-1706-16
日期:——
A group of $N-$4 piperazinyl derivatives of norfloxacin was synthesized and identified by different spectroscopic techniques. The $N-$4 piperazinyl substituent in target compounds 2a-2k, 3a-3c, and 4a and 4b was designed to have different electronic, steric, and physicochemical properties. The antibacterial activity of the newly synthesized compounds was evaluated against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus strains using norfloxacin as a reference. Results showed that most of the tested compounds had higher activity against E. coli and K. pneumoniae than norfloxacin, whereas only five derivatives were more active against P. aeruginosa. On the other hand, all derivatives were less active than norfloxacin against S. aureus. The biological activity of the target compounds, expressed in log MIC, is correlated with lipophilicity, polarizability, and topology parameters. Results showed that none of the calculated parameters could determine the biological activity. Consequently, the total volume of the molecule, bulkiness at C-7, electronic factors, and lipophilicity are important factors that should be considered in the design of new fluoroquinolones.
合成了一组$N$-4哌嗪基诺氟沙星衍生物,并通过不同的光谱技术进行鉴定。目标化合物2a-2k、3a-3c、4a和4b中的$N$-4哌嗪基取代基被设计为具有不同的电子、立体和物理化学性质。评估了新合成化合物对铜绿假单胞菌、大肠杆菌、肺炎克雷伯菌和金黄色葡萄球菌菌株的抗菌活性,以诺氟沙星为参照。结果显示,大多数被测化合物对大肠杆菌和肺炎克雷伯菌的活性高于诺氟沙星,而只有五种衍生物对铜绿假单胞菌的活性更高。另一方面,所有衍生物对金黄色葡萄球菌的活性都低于诺氟沙星。目标化合物的生物活性(以对数最低抑菌浓度表示)与亲脂性、极化率和拓扑参数相关。结果表明,计算的参数均不能确定生物活性。因此,分子的总体积、C-7处的体积、电子因素和亲脂性是设计新型氟喹诺酮时应考虑的重要因素。