Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies
作者:Zaman Ashraf、Abdul Bais、Md. Maniruzzaman Manir、Umar Niazi
DOI:10.1371/journal.pone.0135293
日期:——
A number of penicillin derivatives (4a-h) were synthesized by the condensation of 6-amino penicillinic acid (6-APA) with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF) using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents.
通过将 6-氨基青霉素酸(6-APA)与非类固醇消炎药缩合,合成了一些青霉素衍生物(4a-h)作为抗菌剂。使用 AutoDock Tools 1.5.6 对这些类似物与青霉素结合蛋白(PDBID 1CEF)进行了硅对接研究,以便根据结构研究抗菌数据。青霉素结合蛋白在细菌中起着转肽酶或羧肽酶的作用,在少数情况下还具有转糖基化酶的活性。与标准阿莫西林相比,化合物 4c 和 4e 对大肠杆菌、表皮葡萄球菌和金黄色葡萄球菌具有出色的抗菌潜力。最强的青霉素衍生物 4e 对金黄色葡萄球菌的活性与标准阿莫西林相同。在酶抑制实验中,化合物 4e 抑制大肠杆菌 MurC 的 IC50 值为 12.5 μM。这些化合物 4c 和 4e 的对接得分也证实了它们具有更大的抗菌潜力。这些结果验证了侧链功能和中心五胺核存在的重要性。根据对接结果计算出的结合亲和力以结合能的形式表示,范围在 -7.8 至 -9.2kcal/mol 之间。在所有这些化合物中,五胺核的羧基与受体蛋白的结合力都很强,键长范围为 3.4 至 4.4 Ǻ。本研究的结果证明,衍生物 4c 和 4e 可作为设计和开发强效抗菌剂的结构模板。