Abstract：
Cyanobacterial blooms, a natural phenomenon in freshwater ecosystems, have increased in frequency and severity due to climate change and eutrophication. Some cyanobacteria are able to produce harmful substances called cyanotoxins. These metabolites possess different chemical structures and action mechanisms representing a serious concern for human health and the environment. The most studied cyanotoxins belong to the group of microcystins which are potent hepatotoxins. Anabaenopeptins are another class of cyclic peptides produced by certain species of cyanobacteria, including Planktothrix spp. Despite limited knowledge regarding individual effects of anabaenopeptins on freshwater organisms, reports have identified in vivo toxicity in representatives of freshwater zooplankton by cyanobacterial extracts or mixtures containing anabaenopeptins. This study focused on the isolation and toxicity evaluation of the cyanotoxins produced in the 2022 Planktothrix rubescens bloom in Averno lake, Italy. The three main cyclic peptides have been isolated and identified by nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS) and optical analyses as anabaenopeptins A and B, and oscillamide Y. Ecotoxicological tests on the aquatic model organisms Daphnia magna (crustacean), Raphidocelis subcapitata (algae), and Aliivibrio fischeri (bacterium) revealed that anabaenopeptins A and B do not generate significant toxicity at environmentally relevant concentrations, being also found a stimulatory effect on R. subcapitata in the case of anabaenopeptin A. By contrast, oscillamide Y displayed toxicity. Ecological implications based on ECOSAR predictions align with experimental data. Moreover, long-term exposure bioassays on different green unicellular algae species showed that R. subcapitata was not significantly affected, while Scenedesmus obliquus and Chlorella vulgaris exhibited altered growth patterns. These results, together with the already-known background in literature, highlight the complexity of interactions between organisms and the tested compounds, which may be influenced by species-specific sensitivities, physiological differences, and modes of action, possibly affected by parameters like lipophilicity.
摘要：
蓝细菌水华,淡水生态系统中的一种自然现象，由于气候变化和富营养化，频率和严重程度都有所增加。一些蓝细菌能够产生称为蓝藻毒素的有害物质。这些代谢物具有不同的化学结构和作用机制,代表了对人类健康和环境的严重关注。研究最多的氰基毒素属于微囊藻毒素组，它们是有效的肝毒素。Anabaenoptins是由某些蓝细菌产生的另一类环肽，包括Planktothrixspp。尽管关于anabaenoptins对淡水生物的个体影响的知识有限，报告已经确定了蓝细菌提取物或含有anabaenoptin的混合物对淡水浮游动物的代表的体内毒性。这项研究的重点是在Averno湖中2022年浮游白质花中产生的氰基毒素的分离和毒性评估，意大利。已通过核磁共振（NMR）光谱分离和鉴定了三种主要的环肽，质谱（MS）和光学分析作为anabaenoptinsA和B，和振荡酰胺Y。对水生模式生物Daphniamagna（甲壳类）的生态毒理学测试，头状花序(藻类)，和费氏弧菌（细菌）表明，anabaenoptinsA和B在环境相关浓度下不会产生明显的毒性，在AnabaenopeptinA的情况下，还发现对R.capitulata有刺激作用。振荡酰胺Y显示毒性。基于ECOSAR预测的生态含义与实验数据一致。此外，对不同的绿色单细胞藻类物种的长期暴露生物测定表明，头下绿藻没有受到显著影响，而斜生栅藻和小球藻表现出改变的生长方式。这些结果,加上已知的文学背景，强调生物体和测试化合物之间相互作用的复杂性，这可能会受到特定物种敏感性的影响，生理差异，和行动模式，可能受到亲脂性等参数的影响。
