Nitroreductase (NTR) is a type of cytoplasmic enzyme that depends on flavin mononucleotide or flavin adenine dinucleotide, and that is widely present in tumor cells where it increases during hypoxia. NTR can effectively reduce aromatic nitro compounds to corresponding amino compounds, with the assistance of reduced nicotinamide adenine dinucleotide (NADH). In this study, a nitro-containing fluorescent turn-on probe, TP-NO, was synthesized and characterized. TP-NO exhibited a fast and selective response towards NTR (LOD = 1.96 ng/mL), and which reaction mechanism was proved through molecular docking. In addition, TP-NO has been successfully applied in imaging hypoxia levels in tumor cells, and zebrafish. This work provided a probe that can be applied to investigate NTR in biological systems.

硝基还原酶 (NTR) 是一种依赖于黄素单核苷酸或黄素腺嘌呤二核苷酸的细胞质酶，广泛存在于肿瘤细胞中，在缺氧时它会增加。NTR在还原型烟酰胺腺嘌呤二核苷酸（NADH）的帮助下，可以有效地将芳香族硝基化合物还原为相应的氨基化合物。在这项研究中，合成并表征了一种含硝基的荧光开启探针 TP-NO。TP-NO 对 NTR (LOD = 1.96 ng/mL) 表现出快速和选择性的响应，并且通过分子对接证明了其反应机制。此外，TP-NO 已成功应用于成像肿瘤细胞和斑马鱼的缺氧水平。这项工作提供了一种探针，可用于研究生物系统中的 NTR。