嵊山岛海洋药用生物资源状况调查

对嵊山岛礁生物资源以及邻近海域的微藻资源调查,共发现121种潮间带生物,其中有28种海洋药用生物,包括红条毛肤石鳖(Acanthochiton rubrolineatus)、马粪海胆(Hem icentiotus pulcherrimus)、海萝(Gloiopeltis furcata)等,其中多数是海洋中药或可制成中成药,嵊山岛丰富的海绵资源具有筛选天然活性物质的潜力。嵊山岛邻近海域的产毒藻类包括产麻痹性贝毒(PSP)的链状亚历山大藻(Alexandrium catenatum)、塔玛亚历山大藻(Alexandrium tamarens),产腹泻性贝毒(DSP)的倒卵形鳍藻(D inophysis forti)、具尾鳍藻(D inophysis caudata);产记忆缺失性贝毒(ASP)的尖刺拟菱形藻(Pseudo-Nitzschia pungens)、多列拟菱形藻(Pseudo-Nitzschia multiseries)和多纹拟菱形藻(Pseudo-Nitzschia multistriata);产神经性贝毒(NSP)的短凯伦藻(Kerina breve)以及红色裸甲藻(Gymnodinium sangium)、米氏凯伦藻(Kerina m ikim oto)、环状异甲藻(Heterocapsa circularisqua-ma)等能产生生理活性物质的藻类,其中嵊山岛邻近海域产石房蛤毒素和神经毒素的有毒藻类可能具有药用开发价值。     

藻毒素的类型、危害和防治

介绍了赤潮藻毒素：麻痹性贝毒、短裸甲藻毒素、溶血性毒素、细胞性毒素和氨毒：水华藻毒素：肝毒素、神经毒素、脂多糖内毒素的化学结构、性质和毒害机理等,以及藻毒素的防治方法。     

海洋微生物生物活性物质的研究进展

海洋微生物是海洋生物的重要组成部分.研究结果表明,海洋微生物产生的生物活性物质种类丰富, 主要包括抗肿瘤抗病毒物质、抗生素、生物毒素、酶类、酶抑制剂、多糖、不饱和脂肪酸等等.对海洋细菌、海洋真菌和海洋放线菌所产生的抗菌活性物质和抗肿瘤活性物质进行了综述.     

水母毒素研究进展

水母毒素是一类结构独特而新颖的蛋白质,是一大类潜在的海洋药物先导化合物。该文概述了水母及其毒素的基本特征,详细阐述了水母毒素的结构特征、生理效应和生物活性,为以后研究水母毒素的生物活性和药理作用奠定基础,为充分利用其有效成份,开发新型的海洋生物药物提供更多的线索。     

海洋卡盾藻(香港株)溶血毒素的提取和分离

海洋卡盾藻(Chattonella marina)是我国南方沿海主要的鱼毒性赤潮生物,近年来由该藻形成的赤成已造成多起近岸养殖鱼类大量死亡的事件。为了弄清该藻毒素的基本成分特征,本文研究了室内培养条件下海洋卡盾藻(香港株)溶血毒素的提取方法,观察了溶血毒素对红细胞的溶血过程,采用薄层色谱法对溶血成分进行了初步分析。结果表明:海洋卡盾藻藻细胞的超声波破碎最适条件为功率400W,4℃下处理15min;通过显微镜观察,证实提取的毒素对血红细胞膜具破坏作用;海洋卡盾藻合成的溶血毒素至少含有4种组分,其中1种可能为为脂类,3种为糖脂类。该研究成果有助于我国今后进一步开展鱼毒性赤潮生物毒素的研究。     

海洋生物毒素的损伤机制

海洋生物毒素来源于有毒海洋生物，是一类具有高活性的特殊代谢成分。独特新颖的化学结构造就了其对生物体特殊的损伤机制和剧烈的毒性效应。目前，海洋生物毒素损伤机制的研究特别是靶向离子通道方面已经取得了一定的成果，但仍有许多机制尚不清楚。因此，进一步探索海洋生物毒素的损伤机制十分必要，既有助于防治海洋毒素中毒，又有望将其转化为新型“海洋药物”。本文综述了目前已有报道的海洋生物毒素对生物的损伤机制，包括直接影响细胞膜各类离子通道活性、干扰胞内蛋白磷酸化过程、扰乱线粒体功能、诱发炎症免疫反应，甚至造成细胞死亡等，为后续深入研究海洋生物毒素的其他损伤机制提供参考。     

海洋微生物多样性的研究进展

海洋微生物多样性（marine microorganisms diversity)是指所有海洋微生物种类、种内遗传变异和它们的生存环境的总称。本文介绍了海洋微生物多样性方面的研究和利用进展,包括研究微生物多样性方法的改进,有价值的海洋微生物功能性产品的开发;关于海洋微生物抗肿瘤、抗病毒药物的研究等。     

大田软海绵酸对人胚胎羊膜细胞FL凋亡的影响

大田软海绵酸（Okadaic acid,OA）是一种C38的长链脂肪酸,属聚醚类海洋毒素,是腹泻性贝毒（Diarrhetic shellfish poisoning,DSP）的主要成分,化学结构见下图。最初从大田软海绵（Halichondria Okadai）和隐瓜海绵（H．melanodocia）中分离得到,后发现实际上是由共生于上述两种海绵的利马原甲藻（Prorocentrum lima）所产生。     

我国常见的几种脂溶性贝毒的研究进展

近年我国沿海有毒赤潮的发生频次和规模呈明显的上升趋势,产生的藻毒素沿食物链传递并在贝类体内累积转化生成更为复杂的贝毒素,威胁贝类水产品食用安全和消费者健康。其中大部分贝毒的极性较低,易溶于脂类化合物,被称为脂溶性贝毒(lipophilic shellfish toxins,LST)。目前我国的养殖贝类正面临多种脂溶性贝毒的污染,主要包括大田软海绵酸(okadaic acid,OA)、蛤毒素(pectenotoxin,PTX)、虾夷扇贝毒素(yessotoxin,YTX)、氮杂螺环酸(azaspiracid,AZA)及环亚胺类毒素(cyclic imine,CI)中的gymnodimine(GYM)等几大类毒素。现就这些脂溶性贝毒的化学结构、来源、毒理学特征、食用安全限量及检/监测方法等内容做了系统总结,同时,对我国脂溶性贝毒的来源与贝类染毒状况做了简要概括,并对今后我国脂溶性贝毒的研究方向提出了建议。     

海洋生理活性物质的研究及发展趋势

本文概述海洋生理活性物质特有的特异结构和药理作用,对研究治疗心脑血管疾病、癌症和艾滋病等方面的意义及发展前景。阐述我国近年来从海洋生物活性物质中发现如三丙酮胺、喹啉酮、柳珊瑚酸及其衍生物等观种显著生理活性新化合物及１６种海洋生理活性物质;８种已投入市场的海洋药物及保健品。提出对海洋生理活性物质研制成新药的可行途径及应采取的决策和有效措施;提出应用如基因工程、细胞工程、发酵工程和酶学工程等生物技术来研制、生产出纯度高、质量高、成本低的海洋药物资源物质。海洋生物技术领域的迅速发展,对海洋生物活性物质的研究及开发海洋药物具有广阔的应用前景。     

Biotechnological significance of toxic marine dinoflagellates

Dinoflagellates are microalgae that are associated with the production of many marine toxins. These toxins poison fish, other wildlife and humans. Dinoflagellate-associated human poisonings include paralytic shellfish poisoning, diarrhetic shellfish poisoning, neurotoxic shellfish poisoning, and ciguatera fish poisoning. Dinoflagellate toxins and bioactives are of increasing interest because of their commercial impact, influence on safety of seafood, and potential medical and other applications. This review discusses biotechnological methods of identifying toxic dinoflagellates and detecting their toxins. Potential applications of the toxins are discussed. A lack of sufficient quantities of toxins for investigational purposes remains a significant limitation. Producing quantities of dinoflagellate bioactives requires an ability to mass culture them. Considerations relating to bioreactor culture of generally fragile and slow-growing dinoflagellates are discussed. Production and processing of dinoflagellates to extract bioactives, require attention to biosafety considerations as outlined in this review.     

Assessment of sodium channel mutations in Makah tribal members of the U.S. Pacific Northwest as a potential mechanism of resistance to paralytic shellfish poisoning

The Makah Tribe of Neah Bay, Washington, has historically relied on the subsistence harvest of coastal seafood, including shellfish, which remains an important cultural and ceremonial resource. Tribal legend describes visitors from other tribes that died from eating shellfish collected on Makah lands. These deaths were believed to be caused by paralytic shellfish poisoning, a human illness caused by ingestion of shellfish contaminated with saxitoxins, which are produced by toxin-producing marine dinoflagellates on which the shellfish feed. These paralytic shellfish toxins include saxitoxin, a potent Na⁺ channel antagonist that binds to the pore region of voltage gated Na⁺ channels. Amino acid mutations in the Na⁺ channel pore have been demonstrated to confer resistance to saxitoxin in softshell clam populations exposed to paralytic shellfish toxins present in their environment. Because of the notion of resistance to paralytic shellfish toxins, the study aimed to determine if a resistance strategy was possible in humans with historical exposure to toxins in shellfish. We collected, extracted and purified DNA from buccal swabs of 83 volunteer Makah tribal members and sequenced the skeletal muscle Na⁺ channel (Nav1.4) at nine loci to characterize potential mutations in the relevant saxitoxin binding regions. No mutations of these specific regions were identified after comparison to a reference sequence. This study suggests that any resistance of Makah tribal members to saxitoxin, if present, is not a function of Nav1.4 modification, but may be due to mutations in neuronal or cardiac sodium channels, or some other mechanism unrelated to sodium channel function.     

Quantitation of diarrhetic shellfish poisoning toxins in Chilean mussel using pyrenyldiazomethane as fluorescent labeling reagent

Diarrhetic shellfish poisoning (DSP) is a gastrointestinal disease caused by lipid soluble polyether toxins produced by dinoflagellates and accumulated in shellfish. Diarrhetic shellfish poisoning is a worldwide threat to public health and the shellfish industry. To date, only four lipid soluble polyethers have been known as diarrhetic shellfish toxins. Among them, Okadaic acid (OA), Dinophysistoxin 1 (DTX-1, 35-methyl OA), Dinophysistoxin 2 (DTX-2, OA isomers) and Dinophysistoxin 3 (DTX-3, 7-O-acyl-35-methyl OA), all of which have free carboxilic groups. To perform quantitative analysis of DSP toxins in shellfish samples is a requirement, because DSP toxins are endemic in the Chilean mollusks of the southern regions, and although human symptoms of DSP appear relatively mild in comparison with the Paralytic Shellfish Poisoning (PSP), the necessity of monitoring the chronic effects of continued uptake of low doses of DSP toxins more closely is imperative, since DSP toxins have been described as potent tumor promoters. This paper shows the synthesis pathway of a chromophore, 1-pyrenyldiazomethane (PDAM), a fluorescent labeling reagent for determination of carboxilic acids, using High Performance Liquid Chromatography with fluorescence on-line detection. This procedure was developed in order to have a quantitative method for DSP toxins analysis that would be useful for health public services and private shellfish industries. The features of this labeling reagent are compared against ADAM and used for quantitative analysis of DSP toxins in Chilean mussels and cultured dinoflagellates samples.     

Copepods induce paralytic shellfish toxin production in marine dinoflagellates

Among the thousands of unicellular phytoplankton species described in the sea, some frequently occurring and bloom-forming marine dinoflagellates are known to produce the potent neurotoxins causing paralytic shellfish poisoning. The natural function of these toxins is not clear, although they have been hypothesized to act as a chemical defence towards grazers. Here, we show that waterborne cues from the copepod Acartia tonsa induce paralytic shellfish toxin (PST) production in the harmful algal bloom-forming dinoflagellate Alexandrium minutum. Induced A. minutum contained up to 2.5 times more toxins than controls and was more resistant to further copepod grazing. Ingestion of non-toxic alternative prey was not affected by the presence of induced A. minutum. The ability of A. minutum to sense and respond to the presence of grazers by increased PST production and increased resistance to grazing may facilitate the formation of harmful algal blooms in the sea.     

Variability of paralytic shellfish toxin occurrence and profiles in bivalve molluscs from Great Britain from official control monitoring as determined by pre-column oxidation liquid chromatography and implications for applying immunochemical tests

As the official control monitoring laboratory in Great Britain for the analysis of marine biotoxins in shellfish, Cefas have for the past five years conducted routine monitoring for paralytic shellfish poisoning toxins (PST) using a non-animal alternative method to the mouse bioassay reference method; a refined version of the AOAC 2005.06 pre-column oxidation liquid chromatography method. Application of this instrumental methodology has enabled the generation of data not only on the occurrence and magnitude of PST events, but also the quantitation and assessment of different PST profiles. Since implementation of the method in 2008, results have shown huge variabilities in the occurrence of PSTs, with large spatial and temporal variabilities around the coastline. Mean PST profiles were not found to correlate either with total PST content of the shellfish, the year of sampling or with a few notable exceptions, the shellfish species. Toxin profiles were found to fall into one of four distinct profile types, with one relating solely to the exclusive presence of decarbamoyl toxins in surf clams. The other profile types contained variable proportions of gonyautoxins, N-sulfocarbamoyl toxins, neosaxitoxin and saxitoxin. While some indications of geographical repeatability were noted, this was not observed for all profile types. Consequently, the application of rapid immunochemical testing methods to end product testing would need to be considered carefully given the large differences in PST congener cross-reactivities.     

Production and excretion of okadaic acid,pectenotoxin-2 and a novel dinophysistoxin from the DSP-causing marine dinoflagellate Dinophysis acuta – Effects of light,food availability and growth phase

Diarrhetic shellfish poisoning (DSP) toxins constitute a severe economic threat to shellfish industries and a major food safety issue for shellfish consumers. The prime producers of the DSP toxins that end up in filter feeding shellfish are species of the marine mixotrophic dinoflagellate genus Dinophysis. Intraspecific toxin contents of Dinophysis spp. vary a lot, but the regulating factors of toxin content are still poorly understood. Dinophysis spp. have been shown to sequester and use chloroplasts from their ciliate prey, and with this rare mode of nutrition, irradiance and food availability could play a key role in the regulation of toxins contents and production. We investigated toxin contents, production and excretion of a Dinophysis acuta culture under different irradiances, food availabilities and growth phases. The newly isolated strain of D. acuta contained okadaic acid (OA), pectenotoxins-2 (PTX-2) and a novel dinophysistoxin (DTX) that we tentatively describe as DTX-1b isomer. We found that all three toxins were excreted to the surrounding seawater, and for OA and DTX-1b as much as 90% could be found in extracellular toxin pools. For PTX-2 somewhat less was excreted, but often >50% was found extracellularly. This was the case both in steady-state exponential growth and in food limited, stationary growth, and we emphasize the need to include extracellular toxins in future studies of DSP toxins. Cellular toxin contents were largely unaffected by irradiance, but toxins accumulated both intra- and extracellularly when starvation reduced growth rates of D. acuta. Toxin production rates were highest during exponential growth, but continued at decreased rates when cell division ceased, indicating that toxin production is not directly associated with ingestion of prey. Finally, we explore the potential of these new discoveries to shed light on the ecological role of DSP toxins.     

Recent advances in analytical procedures for the detection of diarrhetic phycotoxins: a review

Okadaic acid and dinophysistoxins are produced by some marine unicellular algae from the plankton and also benthic microalgae and may accumulate in shellfish. These phycotoxins are involved in a gastrointestinal syndrome called diarrhetic shellfish poisoning (DSP), which occurs in humans after consumption of bivalve molluscs. Thousands cases of human poisonings in Europe were caused by consumption of toxic shellfish during the past decade. The rapid detection and the reliable determination of the main phycotoxins implicated in DSP are a major concern for governmental institutions in charge of the sanitary control of seafood safety. Analytical procedures for the detection and determination of DSP toxins can be classified as: bioassays, biochemical methods including immunoassays, or physicochemical methods. Although a large number of methods have been developed, none have been officially validated. A complete panel of tools for DSP toxin analysis should include screening, investigation, and confirmation methods. This paper presents a compilation of recent developments and optimisations of these methods. This revised version was published online in June 2006 with corrections to the Cover Date.     

Harmful algal blooms and eutrophication: Examining linkages from selected coastal regions of the United States

Coastal waters of the United States (U.S.) are subject to many of the major harmful algal bloom (HAB) poisoning syndromes and impacts. These include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera fish poisoning (CFP) and various other HAB phenomena such as fish kills, loss of submerged vegetation, shellfish mortalities, and widespread marine mammal mortalities. Here, the occurrences of selected HABs in a selected set of regions are described in terms of their relationship to eutrophication, illustrating a range of responses. Evidence suggestive of changes in the frequency, extent or magnitude of HABs in these areas is explored in the context of the nutrient sources underlying those blooms, both natural and anthropogenic. In some regions of the U.S., the linkages between HABs and eutrophication are clear and well documented, whereas in others, information is limited, thereby highlighting important areas for further research.     

Winter accumulation of paralytic shellfish toxins in digestive glands of mussels from Arcachon and Toulon (France) without detectable toxic plankton species revealed by interference in the mouse bioassay for lipophilic toxins

Since January 1993, neurological symptoms and rapid deaths (5 to 10 min) were typically observed in the mouse bioassay of acetone extracts of digestive glands from Arcachon and Toulon (France) during the winter season. It was assumed initially that a new lipophilic toxin was present because tests using the AOAC mouse bioassay for paralytic shellfish toxins on acid extracts of whole shellfish meat were negative, no known lipophilic toxins were detected and no toxic phytoplankton species were observed in the area during the poisoning events. In this study, however, preparative isolation of the toxic factor from toxic mussel digestive glands has revealed the presence of paralytic shellfish toxins, the principal ones being gonyautoxins-2 and -3 at Arcachon and gonyautoxins-1, -4, -2 and -3 at Toulon. The toxin concentrations recorded were below levels harmful to consumers and therefore represent a false positive in the mouse bioassay for lipophilic toxins based upon acetone extraction. The origin of the toxins remains to be determined.