Nathane Nunes de Freitas Paloma, Kinoshita Teramoto Kazumi, Ossanes de Souza Alexander, Pinto Ernani
Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, Brazil.
Nuclear Energy in Agriculture Center, University of São Paulo, Piracicaba 13416-000, Brazil.
Toxics. 2023 Jan 29;11(2):128. doi: 10.3390/toxics11020128.
The genus of cyanobacteria is one of the most recurrent in blooms and is associated with the hepatotoxin microcystin production. In addition to cyanotoxins, these bacteria produce a wide range of secondary metabolites with a wide repertoire of activities. The co-occurrence of cyanotoxins and other cyanopeptides during blooming is quite common, and the negative effects are not always limited to one class of toxins, which makes it essential to investigate the toxicity of the other compounds individually. The objective of this study was to isolate the cyanopeptide microcyclamide produced by the strain LTPNA 08 by liquid chromatography coupled to high-resolution mass spectrometry with a quadrupole-time-of-flight analyzer (LC-HR-QTOF-MS/MS) and to evaluate its acute toxicity in embryos of through the Fish Embryo Acute Toxicity (FET) assay. The fraction containing microcyclamide (95% purity) caused lethality in 62% of the embryos after 96 h exposure (50 µg mL), with evidence of cardiotoxicity (cardiac edema). The calculated LC value was 42.98 µg mL (with a concentration range of 37.79-48.89 µg mL). The characterization of the secondary metabolites produced by cyanobacteria and the investigation of the toxicity of these compounds individually are essential for the identification of the substances responsible for negative effects on living organisms and on the ecosystem, in addition to assisting in the development of risk management policies.
蓝藻属是水华中最常见的属之一，与肝毒素微囊藻毒素的产生有关。除了蓝藻毒素外，这些细菌还产生具有广泛活性的多种次生代谢产物。在水华期间蓝藻毒素和其他蓝藻肽同时出现的情况相当普遍，其负面影响并不总是局限于一类毒素，这使得单独研究其他化合物的毒性至关重要。本研究的目的是通过液相色谱-四极杆-飞行时间高分辨质谱联用仪（LC-HR-QTOF-MS/MS）分离菌株LTPNA 08产生的蓝藻肽微环酰胺，并通过鱼类胚胎急性毒性（FET）试验评估其对斑马鱼胚胎的急性毒性。含有微环酰胺（纯度95%）的馏分在暴露96小时（50μg/mL）后导致62%的胚胎死亡，有心脏毒性（心脏水肿）的证据。计算得出的LC50值为42.98μg/mL（浓度范围为37.79-48.89μg/mL）。对蓝藻产生的次生代谢产物进行表征并单独研究这些化合物的毒性，对于确定对生物体和生态系统产生负面影响的物质至关重要，此外还有助于制定风险管理政策。
