Identification of the toxic compounds produced by Sargassum thunbergii to red tide microalgae

The inhibitory effects of methanol extracts from the tissues of three macroalgal species on the growths of three marine red tide microalgae were assessed under laboratory conditions.Extracts of Sargassum thunbergii(Mertens ex Roth) Kuntz tissue had stronger inhibitory effects than those of either Sargassum pallidum(Turner) C.Agardh or Sargassum kjellmanianum Yendo on the growths of Heterosigma akashiwo(Hada) Hada,Skeletonema costatum(Grev.) Grev,and Prorocentrum micans Ehrenberg.Methanol extracts of S.thunbergii were further divided into petroleum ether,ethyl acetate,butanol,and distilled water phases by liquid-liquid fractionation.The petroleum ether and ethyl acetate fractions had strong algicidal effects on the microalgae.Gas chromatography-mass spectrometry analyses of these two phases identified nine fatty acids,most of which were unsaturated fatty acids.In addition,pure compounds of four of the nine unsaturated fatty acids had effective concentrations below 5 mg/L.Therefore,unsaturated fatty acids are a component of the allelochemicals in S.thunbergii tissue.

海洋脂溶性藻毒素虾夷扇贝毒素产毒来源、毒性效应和检测技术研究进展

海洋藻毒素是由海洋有毒微藻分泌产生的有毒物质,可通过食物链传递,导致养殖海产品染毒或者死亡,对人类消费者的健康造成威胁。近年来有毒赤潮频发,海洋藻毒素对海产品的食用安全影响备受关注。虾夷扇贝毒素是一种脂溶性的藻毒素,在世界范围内广有分布。近年来,随着分析化学检测技术被逐渐应用于我国海产品的藻毒素检测和质量监控,虾夷扇贝毒素在我国近海多个海域的贝类样品中被检测出来,但是我国对于该类毒素的毒性作用研究相对较少。本文综述了虾夷扇贝毒素的生物来源、地理分布、化学结构、毒性作用机制及检测方法的研究进展,结合我国国内的调查研究现状,为海洋生态环境监控提出新的建议,即目前除了对常规浮游植物类群进行监控以外,还应加强有毒甲藻孢囊多样性监测,同时,基于虾夷扇贝毒素的毒性作用机制,为海洋药物活性开发和利用提供了新思路。