Chemical properties of marine terpenoids. 1. Some reactions of (6S,10R)-10-bromo-3,11,11-trimethyl-7-methylidenespiro[5,5]undec-2-en-4-one,a sesquiterpenoid from the sea hare Aplysia dactylomela

The structures of products obtained by reductive debromination and CF₃COOH- and KOH-induced transformations of natural chamigrane-type sesquiterpenoid (6S,10R)-10-bromo-3,11,11-trimethyl-7-methylidenespiro[5,5]undec-2-en-4-one (dactylone) isolated from the sea hare Aplysia dactylomela were analyzed. The absolute configurations of the reaction products were established by CD spectra taking into account the configuration of the starting dactylone.     

An unreported bis-abeo cembrane-type diterpenoid with antioxidative and anti-lipoxygenase activities from the muricid gastropod mollusc Chicoreus ramosus

Abstract

The chemical analyses of ethyl acetate-methanol (EtOAc-MeOH) extract of muricid gastropod mollusk, Chicoreus ramosus from the southeastern coast of Indian peninsular led to the identification of unprecedented cembrane-type diterpenoid, which was characterized as (3E, 6E, 10E)-8a-butoxy-17(15→14), 20(12→11)-bis-abeo-cembra-3,6,10,14(17),15-pentaene (1). The structure of the studied cembrane was unambiguously assigned through the extensive spectroscopic experimentations. The antioxidant potentials of the bis-abeo cembrane as determined by in vitro 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid diammonium salt radical quenching potentials were greater (IC₅₀?<?0.40?mg/mL) related to α-tocopherol (IC₅₀?>?0.60?mg/mL). The pro-inflammatory anti-5-lipoxygenase potential of studied cembrane was higher (IC₅₀?<?0.80?mg/mL) related to those demonstrated by ibuprofen and sodium salicylate (IC₅₀?>?0.90?mg/mL).     

庙子湖岛潮间带软体动物的群落特征

为研究舟山庙子湖岛潮间带软体动物的群落结构和生物多样性,于2010年4月至2011年4月对庙子湖岛潮间带进行了4个季节的采样.采用优势度指数、多样性指数、相似性聚类分析、MDS标序和ABC曲线等方法,分析了该岛屿潮间带软体动物的多样性和群落特征.结果表明:潮间带软体动物共计29种,优势种为条纹隔贻贝、粒结节滨螺、带偏顶蛤等.软体动物年平均生物量为1541.81g·m-2,平均栖息密度为925.19 ind·m-2.Margalef丰富度指数为0.72~2.65,以冬季低潮带最高;Pielou均匀度指数为0.26~0.90,以春季高潮带最高;Shannon-Wiener多样性指数为0.68~2.40,以秋季中潮带最高.聚类分析结果表明,不同潮带之间差异性显著,群落非相似性均高于75%;季节差异不明显.主要判别种基本一致,为条纹隔贻贝、带偏顶蛤、粒结节滨螺、短滨螺、覆瓦小蛇螺.ABC曲线分析显示庙子湖岛潮间带软体动物群落结构总体处于稳定状态,受干扰程度较轻.     

杭州湾南岸滩涂贝类养殖环境中污染物的调查

以底栖线虫/挠足类比值的季节变化,反映杭州湾南岸滩涂贝类养殖区的环境污染程度.在4月份中片滩涂上潮带污染较重;6月份东片滩涂下潮带污染较重;8月份东片滩涂上潮带污染较重;10月份东片滩涂污染较重.主要污染物检测结果表明：杭州湾南岸滩涂贝类养殖环境总体上符合国家海洋沉积物的第一类标准,除中部滩涂沉积物中Cu的含量在丰水期超标外,大部分滩涂并没有受到重金属的污染.但滩涂底质中PCB的含量超标严重.4种养殖贝类（泥螺、彩虹明樱哈、缢蛏、青蛤）体内油类和As的残留量均未超标,但Cd、Cr、Pb、Hg、Cu等重金属的残留量有不同程度地超标.这4种贝类生物对Hg的富集能力均很强,以青蛤最甚,其余依次为泥螺、缢蛏、彩虹明樱哈;对Cu的富集能力,泥螺比其他3种强;对Cd的富集能力,依次为青蛤、缢蛏、泥螺、彩虹明樱哈;对PCB的富集能力,以青蛤最强,其余依次为泥螺、彩虹明樱哈.