Cheng Long, He Yan, Tian Yun, Liu Biyun, Zhang Yongyuan, Zhou Qiaohong, Wu Zhenbin
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Chemosphere. 2017 Jun;176:183-191. doi: 10.1016/j.chemosphere.2017.02.110. Epub 2017 Feb 24.
N-Phenyl-1-naphthylamine (PNA) and N-Phenyl-2-naphthylamine (PNA) are both widely used as antioxidant and plant secondary metabolites. In this study, growth, esterase, photosynthetic activity and cell membrane integrity were used as biomarkers to compare biotoxicity of PNA and PNA on Microcystis aeruginosa. According to the results, a dose-response relationship was observed only between PNA concentrations and growth inhibition. The EC (48 h) of PNA calculated from growth inhibition was 16.62 μM, while that of PNA was not detected. When the esterase and photosynthetic activity were applied to evaluate the biotoxicity, it was found that a concentration of 20 μM PNA, PNA caused reduction of esterase activity and Fv/Fm of M. aeruginosa to 22.2 and 3.3%, 97.5 and 92.1%, respectively, after 48 h exposure. The percentage of membrane-damaged cells was increased as PNA exposure concentration increased, but that was not detected when exposure to PNA. The difference substituted position in the molecular structure of PNA and PNA leads to different toxicological properties and only PNA was found highly toxic to M. aeruginosa. The toxicity is due to that only PNA can be biotransformed to 1,4-naphthoquinone, which could induce overproduction of intracellular ROS as well as result in oxidative damage and growth inhibition of test organism.
N-苯基-1-萘胺（PNA）和N-苯基-2-萘胺（PNA）均被广泛用作抗氧化剂和植物次生代谢产物。在本研究中，将生长、酯酶、光合活性和细胞膜完整性用作生物标志物，以比较PNA和PNA对铜绿微囊藻的生物毒性。根据结果，仅在PNA浓度与生长抑制之间观察到剂量-反应关系。由生长抑制计算得出的PNA的48小时半数效应浓度（EC）为16.62μM，而PNA的该值未检测到。当应用酯酶和光合活性来评估生物毒性时，发现20μM的PNA、PNA在暴露48小时后，分别使铜绿微囊藻的酯酶活性和Fv/Fm降低至22.2%和3.3%、97.5%和92.1%。膜受损细胞的百分比随PNA暴露浓度的增加而增加，但暴露于PNA时未检测到这种情况。PNA和PNA分子结构中的取代位置差异导致了不同的毒理学特性，并且仅发现PNA对铜绿微囊藻具有高毒性。毒性归因于只有PNA可以生物转化为1,4-萘醌，这会诱导细胞内活性氧的过量产生，并导致受试生物的氧化损伤和生长抑制。
