海鞘类天然产物的临床研究进展

综述目前已进入临床研究阶段的海鞘类天然化合物ET-743．Didemnin B，Aplidine的研究进展。     

两株海鞘来源放线菌 Streptomyces coelicoflavus和 Nocardiopsis dassonvillei的次级代谢产物及其生物活性研究

目的 从采自中国黄海的威海海域的柄海鞘来源放线菌Streptomyces coelicoflavus(HQA809) 和史氏菊海鞘来源放线菌Nocardiopsis dassonvillei(HQA404) 中分离、鉴定具有生物活性的次级代谢产物。方法 运用硅胶柱层析、Sephadex LH-20凝胶柱层析和半制备HPLC等方法分离化合物,运用核磁、质谱等现代波谱分析方法对化合物进行结构鉴定,并对化合物进行抗菌、卤虫致死、α-糖苷酶抑制活性和细胞毒活性评价。结果 从 Streptomyces coelicoflavus(HQA809) 中分离鉴定了2个吡喃酮类化合物 (1,2),从 Nocardiopsis dassonvillei(HQA404) 中分离鉴定了1个吩嗪类化合物 (3) 和1个苯酚类化合物 (4);化合物3对鳗弧菌 (Vibrio anguillarum) 和副溶血弧菌 (Vibrio parahaemolyticus) 显示出较强的抑菌活性,其MIC值分别为50 μmol/L和25 μmol/L。结论 海鞘来源放线菌可以作为发现新颖的生物活性物质的潜在来源。     

Occurrence and Seasonal Monitoring of Domoic Acid in Three Shellfish Species from the Northern Adriatic Sea

As filter feeders, bivalves and ascidians can accumulate contaminants present in the environment and pass them on to higher food chain levels as vectors. The consumption of bivalves contaminated with the potent neurotoxin domoic acid (DA) can cause amnesic shellfish poisoning in humans. The aim of this study was to determine seasonal differences in occurrence and accumulation of this phycotoxin in European oysters (Ostrea edulis Linnaeus, 1758) (n = 46), Queen scallops (Aequipecten opercularis Linnaeus, 1758) (n = 53), and edible ascidians of the Microcosmus spp. (n = 107), originating from the same harvesting area in the Northern Adriatic Sea. The quantification was performed using ultra-performance liquid chromatography–tandem mass spectrometry (LC-MS/MS) preceded by derivatization with dansyl chloride. DA was found in very low concentrations throughout the year, with a maximum value of 810 μg/kg in Queen scallops. This study reveals differences in the occurrence and accumulation of DA between Queen scallops and the other two investigated species (oysters and ascidians) and the highest concentrations during the colder part of the year. Even though DA was detected in all of them, Queen scallops showed higher DA accumulation compared to the other two (p < 0.001), hence representing a sentinel species suitable for the monitoring of DA level in seafood.     

Immune roles of a rhamnose-binding lectin in the colonial ascidian Botryllus schlosseri

The present paper describes the immune role played by a recently identified (Gasparini et al. 2008) member of the rhamnose-binding lectin (RBL) family from the colonial ascidian Botryllus schlosseri.B. schlosseri RBL (BsRBL) can activate phagocytes through: (i) induction of their directional movement towards the source of the molecule; (ii) modification of cytoskeleton, required for shape changes; (iii) stimulation of the respiratory burst, and consequent production of reactive oxygen species (ROS) with microbicidal activity, including superoxide anions and peroxides; and (iv) increase in the ability to phagocytose foreign particles. RBL also induces the synthesis and release, by cytotoxic morula cells (MCs), of cytokines recognised by anti-IL1α and anti-TNFα antibodies. At high concentrations, BsRBL induces degranulation of MCs and the consequent release of the cytotoxic enzyme phenoloxidase into the medium. Results are consistent with the existence of cross-talk between B. schlosseri immunocytes (phagocytes and MCs). In addition, a three-dimensional model for BsRBL is presented.