黄海绿潮浒苔提取物的化感效应及化感物质的分离鉴定

化感作用是浒苔绿潮暴发的重要原因之一，目前，对于浒苔产生化感物质的结构、种类以及产量的研究鲜有报道。本文针对黄海浒苔绿潮致灾藻种，利用毒性鉴别程序（TIE）对其体内的化感物质进行分离提取及结构鉴定，明确了浒苔产生化感物质的主要成分。首先用石油醚、乙酸乙酯和甲醇3种有机溶剂分别对新鲜浒苔进行提取，得到3种不同溶剂粗提物，其中乙酸乙酯粗提物的抑藻活性最强，对测试物种中肋骨条藻的半数有效浓度（96h-EC₅₀）值为22.25 mg/L；其次对乙酸乙酯粗提物进行萃取分离得到初步提纯物，其对中肋骨条藻的96h-EC₅₀值为21.12 mg/L；然后用硅胶层析柱对上述初步提纯物进行分离，共得到6种组分，其中抑藻活性最强的组分对中肋骨条藻的96h-EC₅₀值为10.57 mg/L；最后，对新鲜浒苔提取物用红外光谱和气相色谱-质谱联用仪进行检测，实验结果表明主要化感物质为:4，7，10，13，16，19-二十二碳六烯酸、2-十六碳烯酸、棕榈酸、5，8，11，14，17-二十碳五烯酸、9，12-十八碳二烯酸、9，12，15-十六碳三烯酸、花生四烯酸、13-二十二碳烯酸等8种脂肪酸。研究结果对于系统阐释浒苔绿潮暴发机制具有重要意义。

Allelopathy of extracts of Ulva prolifera on green tides in the Yellow Sea and the identification of the allelochemicals

Allelopathy is one of the important factors of green tide, while the studies of structure, category and yield of allelochemicals released by Ulva prolifera are lacking. Based on the procedure of toxicity identification evaluation(TIE), this study was carried to extract and identify the allelochemicals from the disaster-causing algaes on green tides in the yellow sea, so that we can confirm the main components of allelochemicals realeased by U. prolifer. Firstly, U. prolifera was extracted with three different organic solvents, which include petroleum ether, ethyl acetate and methanol. Three different solvents crude extracts were obtained and the ethyl acetate extract has the stongest effect on anti-algal activity, the 96h-EC₅₀ value against S. costatum was 22.25 mg/L. Next, the primary extracts were obtained by isolating ethyl acetate extract, the 96h-EC₅₀ value against S. costatum was 21.12 mg/L. Then, chromatography column was used to purify the above primary extracts and six components were certained, the 96h-EC₅₀ value of the most toxic component against S. costatum was 10.57 mg/L. Finally, the possible allelochemicals of U. prolifera dry tissues were detected using Gas chromatography-mass spectrometry (GC-MS) and infrared spectroscopy (IR) analysis. Eight fatty acids were identified for both species:4,7,10,13,16,19-docosahexaenoic acid, 2-Hexadecenoic acid,Hexadecanoic acid, 5,8,11,14,17-eicosapentaenoate, 9,12-octadecadienoic acid, 9,12,15-octadecatrienoic acid, arachidonic acid, 13-docosenoic acid. The results of the study play a significant role in systematically illustrating the mechanism of the outbreak of green tides.