Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, China; Dalian University of Technology, School of Food and Environment, Dagong Road, Panjin 124221, China.
Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, China.
Sci Total Environ. 2019 Apr 10;660:269-276. doi: 10.1016/j.scitotenv.2019.01.056. Epub 2019 Jan 7.
Allelopathy has been regarded as chemical weapons for marine phytoplankton that enhanced competition ability in stressful conditions, especially during blooms. In a previous study, Chaetoceros curvisetus achieved growth advantage to Skeletonema costatum by producing allelochemicals. However, C. curvisetus allelochemicals have never been isolated and characterized until now. In this study the extraction and purification conditions were systematically optimized and C. curvisetus filtrate extracts were used to assess bioactive effects on the growth of S. costatum. The preliminary results showed that filtrates of C. curvisetus in exponential phase extracted under a temperature lower than 50°C could ensure a stronger activity of allelochemicals. Ethyl acetate extraction showed significant allelopathic effect and the wavelength of characteristic absorption was 255-260nm. Then C. curvisetus allelochemicals were isolated by Si-SPE, Sephadex-25 columns and C18 column and identified by HPLC-electrospray time-of-flight mass spectrometry (ESI TOFMS). It was found that the molecular weight of C. curvisetus allelochemicals was 314 and the allelochemical was supposed to be 2- ((2-cyanophenyl) amino)-2-oxoethyl,3-cyclohexyl propanoate.
化感作用被认为是海洋浮游植物的化学武器，使它们在压力条件下，尤其是在水华期间，增强竞争能力。在之前的研究中，角毛藻通过产生化感物质对中肋骨条藻取得了生长优势。然而，直到现在，角毛藻的化感物质还从未被分离和表征过。在这项研究中，我们系统地优化了提取和纯化条件，并使用角毛藻滤液提取物来评估其对中肋骨条藻生长的生物活性影响。初步结果表明，在低于 50°C 的温度下提取处于指数生长期的角毛藻滤液，可以确保化感物质具有更强的活性。乙酸乙酯萃取显示出显著的化感效应，特征吸收波长为 255-260nm。然后，通过 Si-SPE、Sephadex-25 柱和 C18 柱对角毛藻化感物质进行分离，并通过高效液相色谱-电喷雾飞行时间质谱（ESI-TOFMS）进行鉴定。发现角毛藻化感物质的分子量为 314，化感物质可能是 2-（（2-氰基苯基）氨基）-2-氧代乙基、3-环己基丙酸酯。
