In this study, we aim to explore the allelochemicals of marine brown algae Sargassum fusiforme and the mechanism of allelopathy effect on Heterosigma akashiwo. Six potential allelopathic substances, palmitic acid, arachidonic acid, α-linolenic acid (ALA), fucosterol, 24-hydroperoxy-24-vinylcholesterol, and saringosterowere, were isolated and identified from S. fusiforme by column chromatography, NMR, TOF-MS and GC‐MS analyses. The ALA and 24-hydroperoxy-24-vinylcholesterol showed remarkable inhibitory activities on H. akashiwo growth. Besides, the allelopathic mechanism between the ALA and H. akashiwo was preliminarily investigated. The results indicated that the activities of SOD and POD of H. akashiwo gradually decreased under high ALA concentration. The reduction of photosynthetic pigments and chlorophyll fluorescence parameters, as well as apparent electron transport rate in H. akashiwo cells, aggravated gradually with increasing the concentration of the ALA. In summary, this study revealed the responses of morphology and physiology of H. akashiwo when exposed by ALA, while revealing the potential of macroalgae in red tide control.

本研究旨在探讨海洋褐藻马尾藻的化感物质及其对赤潮异藻的化感作用机制。通过柱色谱、NMR、TOF-MS 和质谱分析从S. fusiforme中分离和鉴定了六种潜在的化感物质：棕榈酸、花生四烯酸、α-亚麻酸 (ALA)、岩藻甾醇、24-氢过氧-24-乙烯基胆固醇和沙林甾醇。 GC-MS 分析。 ALA和24-氢过氧-24-乙烯基胆固醇对赤潮红藻的生长具有显着的抑制活性。此外，还初步探讨了ALA与赤潮红藻之间的化感作用机制。结果表明，在高ALA浓度下，赤潮鱼的SOD和POD活性逐渐降低。赤潮红藻细胞内光合色素和叶绿素荧光参数以及表观电子传递速率的降低随着ALA浓度的增加而逐渐加剧。总之，本研究揭示了赤潮红藻在ALA暴露下的形态和生理反应，同时揭示了大型藻类在赤潮控制中的潜力。