摘要
氮杂螺环酸毒素(azaspiracids,AZAs)隶属八大类海洋贝类毒素,为一类含氮且具独特螺环结构的聚醚类毒素。采用液相色谱-三重四级杆复合离子阱质谱,研究了分离自中国近海的1株氮杂螺环酸产毒藻腹孔环胺藻(Azadinium poporum,AZDY06)所产氮杂螺环酸毒素在栉孔扇贝体内的蓄积、分布和生物转化机制。通过将栉孔扇贝暴露产毒藻的方式,分析扇贝内脏团、裙边、闭壳肌和其他可食组织4个组织部位的AZAs及其代谢产物分布,研究栉孔扇贝对毒素的代谢机理。结果表明,AZDY06主要产生AZA2毒素,单细胞产毒能力最高为(7.05±0.52)fg/cell;扇贝12 h内摄食5×10~7个产毒藻细胞后,体内AZAs毒素含量已超欧盟安全限量,达165.3μg AZA1eq/kg,蓄积效率为78.2%。AZAs毒素在扇贝各组织间分布存在显著差异:内脏团>其他可食组织>外套膜>闭壳肌。AZA2在扇贝中潜在转化方式为羟基化、去羧基化和氧化,共生成4种代谢产物:AZA6、AZA12、AZA19和AZA23,其中AZA19为最主要代谢产物,约占总毒素40%,其他代谢产物含量较低。本研究证明中国近海分布氮杂螺环酸产毒藻毒性危害较强,建议有关部门加快制定AZAs限量标准。
Azaspiracids(AZAs)are a group of lipophilic polyether compounds first discovered in Ireland and have been implicated in shellfish poisoning incidents.Known toxin-producing genera have rapidly increased and now comprise six species,including Azadinium spinosum,A.obesum,A.poporum,A.polongum,A.caudatum,and A.dexteroporum.Approximately40different analogs have been reported to differ in structure and toxicity,of which AZA1,AZA2,and AZA3are the most important ones based on occurrence and toxicity.AZAs are a variety of nitrogen-containing polyether toxins,which include a unique spiral ring assembly,a heterocyclic amine,and an aliphatic carboxylic acid moiety.The consumption of polluted shellfish can cause human intoxication,with symptoms including nausea,vomiting,diarrhea and stomach cramps,which is similar to diarrhetic shellfish poisoning(DSP).Nowadays,in order to guarantee food security,the developed countries have begun to prioritize shellfish monitoring.A regulatory level of160μg AZA1eq/kg in the shellfish tissues is implemented in many countries all over the world,but our country does not have a regulation about this.Azadinium poporum is a small dinoflagellate member of the family Amphidomataceae,which is known for the production of AZAs.Twenty two out of25A.poporum strains isolated in China have proven to be AZA-producing strains,and show a large variability in the AZA profile among different strains.This status underlines the high-risk potential of A.poporum blooms with subsequent shellfish intoxication for the Asian Pacific Ocean.AZA accumulation by bivalve mollusks occurs frequently,while blue mussels were found to accumulate by far the highest concentration.Meanwhile,AZAs have been found in various species of bivalve mollusks such as oysters,mussels,scallops,and clams along Chinese coastline.As AZA is a recently discovered toxin,the bloom dynamics,transfer kinetics,and pathways of AZAs into bivalve mollusks are just beginning to be explored.Accumulation and distribution of AZA toxins in bivalve shellfish could be correlated in time and space to blooms of Azadinium species.Subsequent accumulation and trophic transfer can intoxicate higher trophic-level consumers and eventually pass into human beings.To investigate the hazard formation process,two transfer routes must be taken into consideration:AZAs could be accumulated by bivalve shellfish or plankton vectors from toxin producing algae.In conclusion,a direct link between AZA accumulation by bivalve shellfish and A.poporum must be investigated for food safety control and monitoring plans.Liquid chromatography coupled with quadrupole linear ion trap tandem mass spectrometry was established for the evaluation of AZA accumulation,distribution,and biotransformation in scallops.Toxin-producing alga A.poporum(AZDY06),isolated from China,was cultured and exposed to Chlamys farreri.The results showed that AZA2is the dominant toxin of AZDY06,with toxin production capacity up to(7.05±0.52)fg/cell.After12h exposure experiments with5′107cells AZDY06ingested by every C.farreri,AZAs in mussels reached the highest concentration and exceeded EU regulatory limits.The concentration was165.3μg AZA1eq/kg,while total accumulation efficiency reached78.2%.The distribution of AZA toxins showed significant differences between organs,with gill>viscera>pallium>muscle.Four AZA analogs including AZA19,AZA12,AZA6,and AZA23were found in all organs.AZA19was the main metabolite with a proportion of40%,while other metabolites were found more rarely.This study proved that the hazard of A.poporum(AZDY06)isolated from China is strong and underlined that AZA19was present at significant levels after only6h and until the end of the study.Therefore,this analog needs to be considered as the major metabolite that can affect human health.It is highly recommended to quickly formulate AZA limits,based on this analysis of raw bivalves by LC-MS/MS.
作者
吴海燕
李清云
邴晓菲
郭萌萌
顾海峰
翟毓秀
谭志军
WU Haiyan;LI Qingyun;BING Xiaofei;GUO Mengmeng;GU Haifeng;ZHAI Yuxiu;TAN Zhijun(Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture; Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071;College of Chemistry and Molecular Engineering, The Science and Technology University of Qingdao, Qingdao 206011, China;Third Institute of Oceanography, State Oceanic Administration, Xiamen 361000, China)
出处
《中国水产科学》
CAS
CSCD
北大核心
2017年第6期1298-1306,共9页
Journal of Fishery Sciences of China
基金
中国水产科学研究院基本科研业务费项目(2017HY-YJ0201
2017GH14)
山东省重点研发计划(2016GSF120018)项目
