Three series of azole piperazine derivatives that mimic dicyclotyrosine (cYY), the natural substrate of the essential Mycobacterium tuberculosis cytochrome P450 CYP121A1, were prepared and evaluated for binding affinity and inhibitory activity (MIC) against M. tuberculosis. Series A replaces one phenol group of cYY with a C3-imidazole moiety, series B includes a keto group on the hydrocarbon chain preceding the series A imidazole, whilst series C explores replacing the keto group of the piperidone ring of cYY with a CH₂-imidazole or CH₂-triazole moiety to enhance binding interaction with the heme of CYP121A1. The series displayed moderate to weak type II binding affinity for CYP121A1, with the exception of series B 10a, which displayed mixed type I binding. Of the three series, series C imidazole derivatives showed the best, although modest, inhibitory activity against M. tuberculosis (17d MIC = 12.5 μg/mL, 17a 50 μg/mL). Crystal structures were determined for CYP121A1 bound to series A compounds 6a and 6b that show the imidazole groups positioned directly above the haem iron with binding between the haem iron and imidazole nitrogen of both compounds at a distance of 2.2 Å. A model generated from a 1.5 Å crystal structure of CYP121A1 in complex with compound 10a showed different binding modes in agreement with the heterogeneous binding observed. Although the crystal structures of 6a and 6b would indicate binding with CYP121A1, the binding assays themselves did not allow confirmation of CYP121A1 as the target.

三个系列唑哌嗪衍生物的模拟dicyclotyrosine（CYY），必需的天然底物的结核分枝杆菌的细胞色素P450 CYP121A1，制备并评价针对结合亲和力和抑制活性（MIC）的结核分枝杆菌。系列A替代了一个酚基团CYY的与C3-咪唑部分，系列B包括在系列A咪唑之前的烃链上的酮基，而C系列探索用CH替换CYY的哌啶酮环的酮基₂ -咪唑或CH _2-三唑部分，以增强与CYP121A1血红素的结合相互作用。除B 10a系列外，该系列对CYP121A1显示中等至弱II型结合亲和力，其中显示了混合的I型绑定。在这三个系列中，系列C咪唑衍生物显示出对结核分枝杆菌的最佳抑制作用，尽管抑制作用适中（17d MIC = 12.5μg/ mL，17a 50μg/ mL）。确定了与系列A化合物6a和6b结合的CYP121A1的晶体结构，这些化合物显示，咪唑基团位于血红素铁的正上方，并且两个化合物的血红素铁和咪唑氮之间的键合距离为2.2。由CYP121A1的1.5晶体结构与化合物10a配合生成的模型显示出不同的结合模式，与观察到的异质结合相符。虽然6a的晶体结构6b和6b表示与CYP121A1结合，结合试验本身不允许确认CYP121A1为靶标。