Sixteen new Ciprofloxacin derivatives were designed and successfully synthesized. In an in silico experiment, lipophilicity was established for obtained compounds. All compounds were screened for antimicrobial activity using standard and clinical strains. As for Gram-positive hospital microorganisms, all tested derivatives were active. Measured MICs were in the range 1–16 µg/mL, confirming high antimicrobial potency. Derivative 12 demonstrated activity against all standard Gram-positive Staphylococci, within the range of 0.8–1.6 µg/mL and was confirmed as the leading structure with MICs 1 µg/mL for S. pasteuri KR 4358 and S. aureus T 5591 (clinical strains). All compounds were screened for their in vitro cytotoxic properties via the MTT method. Three of the examined compounds (3, 11 and 16) showed good activity against cancer cells, and in parallel were found not to be cytotoxic toward normal cells. Doxorubicin SI ranged 0.14–1.11 while the mentioned three ranged 1.9–3.4. Selected Ciprofloxacin derivatives were docked into the crystal structure of topoisomerase II (DNA gyrase) in complex with DNA (PDB ID: 5BTC). In summary, leading structures were established (3, 11, 12 and 16). We have observed poor results in preformed studies for disubstituted derivatives, suggesting that 3-oxo-4-carboxylic acid core is the active DNA-gyrase binding site, and when structural changes were made in this fragment, there was an observed decrease in antibacterial potency.
我们设计并成功合成了十六种新的环丙沙星衍生物。在一项硅学实验中,确定了所获化合物的亲脂性。利用标准菌株和临床菌株对所有化合物进行了抗菌活性筛选。对于革兰氏阳性医院微生物,所有测试的衍生物都具有活性。测得的 MIC 在 1-16 µg/mL 范围内,证实了很高的抗菌效力。衍生物 12 对所有标准革兰氏阳性金黄色葡萄球菌都有活性,范围在 0.8-1.6 µg/mL 之间,并被确认为主要结构,对巴氏杆菌 KR 4358 和金黄色葡萄球菌 T 5591(临床菌株)的 MIC 为 1 µg/mL。所有化合物都通过 MTT 法进行了体外细胞毒性筛选。其中三种化合物(3、11 和 16)对癌细胞表现出良好的活性,同时发现它们对正常细胞没有细胞毒性。多柔比星的 SI 值为 0.14-1.11,而上述三种化合物的 SI 值为 1.9-3.4。选定的环丙沙星衍生物与拓扑异构酶 II(DNA 回旋酶)与 DNA 复合物的晶体结构对接(PDB ID:5BTC)。总之,建立了主要结构(3、11、12 和 16)。我们观察到二取代衍生物的预成型研究结果不佳,这表明 3-氧代-4-羧酸核心是 DNA-gyrase 的活性结合位点,当对该片段进行结构改变时,抗菌效力会下降。