Direct Reductive Cyanation of A 2-Pyrrolidinone Chiral Building Block Bearing An Unprotected Hydroxyl Group: A Stereoselective Synthesis of N-Methyl-2-epi-bulgecinine

报道手性合成砌块(4S,5R)-N-芐氧基-5-羟甲基-2-吡咯烷酮(3a)的直接还原氰基化及产物的立体化学与转化研究.含未保护羟基的内酰胺用L; iAlH_4/KCN体系直接还原氰基化,生成比例为69:; 31的2,5-反式/顺式非对映立体异构体.与文献类似结果对比显示,氰基负离子对5-羟甲基-△-1-吡咯啉鎗中间体的加成主要受立体电子效应和C(5; )位取代基(羟甲基)与进攻试剂间烯丙型1,3-位阻控制.该混合物在碱性条件下水解,生成比例为10:; 90的2,5-反式/2,5-顺式-bulgecinine衍生物.这一结果表明氰基水解反应伴随着在C(2)位发生了有合成价值的串联差向异构化.由此; 建立了立体选择性地合成2,5-顺式(-)-N-甲基-2-别-bulgecinine的简便方法.The direct reductive cyanation of N-benzyl-4-benzyloxy-5-hydroxymethyl-2-pyrrolidinone (3a), a lactam bearing a free hydroxyl group, has been achieved with the LiAlH4/KCN combination. The reaction afforded 2,5-trans-2-cyano-5hydroxylmethyl-4-benzyloxy-pyrrolidine (5a) and its cis-diastereomer 5b in a ratio of 69: 31 with a combined yield of 63%. The observed 2,5-trans-stereoselectivity is suggested to be resulted from both stereoelectronic effect and allylic 1,3-strain between the hydroxymethyl group at C(5) and the incoming cyanide anion on the presumed Delta-1 pyrrolinium ion intermediate. The subsequent hydrolysis of the cyano group of the diastereomeric mixture 5a/5b (trans: cis=69: 31) under basic conditions afforded the corresponding 5-hydroxymethyl-4-benzyloxyproline with 2,5-cis-diastereomer as the major diastereomer (trans: cis= 10: 90). This result implies that a synthetically useful epimerization at C(2) has occurred concomitantly. This unexpected result afforded a concise and highly stereoselective synthesis of 2,5-cis-(-)-N-methyl-2-epi-bulgecinine.National Natural Science Foundation of China [21332007]; Program for; Changjiang Scholars and Innovative Research Team in University of; Ministry of Educatio

少穗竹和四季竹竹笋的营养成分分析

对福建省华安竹种园2种少穗竹属笋用竹少穗竹和四季竹竹笋的基本营养成分进行测定分析。结果表明:四季竹竹笋的含水量、灰分、脂肪含量高于少穗竹,但蛋白质含量低于少穗竹;而少穗竹竹笋氨基酸、必需及半必需氨基酸、呈味氨基酸总含量高于四季竹。厦门市科学技术局科研项目(编号:3502Z20102003和3502Z20144072

5种牡竹属笋用竹竹笋营养成分之比较

对福建省华安县竹种园5种牡竹属笋用竹云南甜龙竹、版纳甜龙竹、勃氏甜龙竹、马来甜龙竹和梁山慈竹竹笋营养进行成分比较。结果表明:5种笋用竹鲜竹笋含水量均接近或超过90%,口感较好;灰分含量勃氏甜龙竹竹笋的最高,达0.893%,版纳甜龙竹最低（0.340%）;蛋白质含量最高的是马来甜龙竹（1.717%）,最低的是版纳甜龙竹（1.260%）;勃氏甜龙竹（0.281%）和云南甜龙竹（0.292%）脂肪含量较低,马来甜龙竹（1.134%）和梁山慈竹（1.083%）脂肪含量较高;勃氏甜龙竹（0.655%）和云南甜龙竹（0.666%）粗纤维含量较低,而梁山慈竹、版纳甜龙竹和马来甜龙竹含量相近,达较高水平,分别达0.953%、0.894%和0.879%。5种竹笋均含有17种氨基酸,氨基酸总含量最高的是勃氏甜龙竹(227.64 mg·g-1),最低的是马来甜龙竹(120.43 mg·g-1);必需半必需氨基酸总含量最高的是勃氏甜龙竹（84.26%）,最低的是马来甜龙竹（50.67%）;呈味氨基酸总量最高的是勃氏甜龙竹,达212.79 mg·g-1,其次依次为梁山慈竹(164.71 mg·g-1)、版纳甜龙竹(156.35 mg·g-1)、云南甜龙竹(141.44 mg·g-1)和马来甜龙竹(115.83 mg·g-1)。厦门市科学技术局科研项目资助(3502Z20102003;3502Z20144072

陈征经济学思想述评

本文评述了陈征在几十年的学术生涯中,始终如一地坚持运用《资本论》的立场、观点和方法,研究中国社会主义经济所取得的主要学术成果和严谨的治学精神。文章特别着重从以下几个方面分析评价了陈征的经济思想:1.紧密结合新的历史条件,坚持与发展马克思的劳动价值学说;2.对社会主义地租理论的探索与创新;3.关于《资本论》与社会主义市场经济的理论探索

Distribution and Species of Mercury in Water and Sediments from Huangpu River

黄浦江江水的总汞、溶解态汞和颗粒汞含量变化较大,其平均值分别为(0.4±0.44)ng/mL、(0.27±0.42)ng/mL和(0.13±0.10)ng/mL,江水中汞以溶解态汞为主.黄浦江沉积物的总汞含量为70.52ng/g~387.30ng/g,平均汞含量为(204.03±97.41)ng/g.江水和沉积物中汞的沿江分布具有中游高,上游和下游低的特征,西渡—南浦大桥江段汞含量为整个黄浦江最高的江段,汞的分布特征与两岸工农业布局相一致.沉积物总汞与有机质显著相关,沉积物中高汞含量的地点都在高水汞点的下游,与河流的动力沉积特点一致.沉积物中汞以可交换态、腐殖酸结合态、残渣态为主,少量为碳酸盐结合态.从上游到下游,沉积物中可交换态汞具有两端高中间低的特点,而残渣态汞与此相反.在剖面方向上,沉积物中的汞主要集中在残渣态,少量为腐殖酸结合态,可交换态及碳酸盐结合态,随着深度增加残渣态所占比例不规则增加.愈接近长江口,沉积物中的重金属愈容易被重新激活.Levels of total mercury, soluble mercury and particle mercury in water of Huangpu River change greatly, their average values are (0.40.44)ng/mL, (0.270.42)ng/mL, (0.130.10)ng/mL respectively. Mercury in water is mainly in the form of soluble mercury. Average mercury content in sediment of Huangpu River is relative high and up to (204.0397.41)ng/g, with a range of 70.52ng/g387.30ng/g. Mercury content is high in the middle reach of Huangpu River, especially in section of Xidu-Nanpu Bridge, and low in upstream and downstream. Distribution of mercury is hightly related with distribution of industry plants and farming. Locations with high mercury content in sediment are in the downstream of locations with high mercury content in water. Mercury (in sediments) is mainly in the form of residue, exchangeable ions, and humics-bound, seldom is in the form of carbonate-bound. Contrary to residue-bound mercury, exchangeable mercury is low in the middle reach, and high in upstream and downstream. There mainly are residue-bound mercury and little humics-bound mercury, exchangeable mercury, and carbonate-bound mercury in sediment in profile, and the residue-bound mercury increases irregularly with depth. Nearing the Mouth of Yangtze River, mercury in sediment becomes more active.国家自然科学基金资助项目(20077016);; 中国博士后基金项目(2002032148);; 厦门大学行动计划联合资助项目(0660-X01114

Grazing pressure of microzooplankton on phytoplankton in Xiamen Waters

应用稀释法对厦门海域浮游植物生长率(k)和微型浮游动物的摄食率(g)进行了估算。结果显示:5月,西海域18测站k、g分别为2.41、0.78d 1;南部海域27测站分别为2.43、1.32d 1。8月18测站k、g分别为3.00、2.90d 1;27测站分别为1.94、0.91d 1。说明厦门海域作为典型的亚热带港湾,具有高的k、g值。分粒级研究结果显示:8月,18测站微型浮游动物对微型浮游植物(Micro)具摄食偏好;而27测站微型浮游动物对Micro和Nano级的摄食率相近。应用流式细胞技术研究18测站微微型真核浮游植物的k、g,结果表明:春季,生长率和摄食率分别为2.00、1.02d 1;夏季分别为1.52、0.96d 1。Phytoplankton growth rate and microzooplankton grazing rate were estimated in Xiamen Waters using dilution method. In spring, phytoplankton growth rate (k) and microzooplankton grazing rate (g) were 2.41d~(-1)0.78 d~(-1), respectively, at station 18, Western Xiamen Waters, and kg were 2.43 d~(-1)1.32 d~(-1), respectively, at station 27 which represents Southern Xiamen Waters. In spring, kg were 3.00 d~(-1)2.90 d~(-1), respectively, at station 18, kg were 1.94 d~(-1)0.91d~(-1), respectively, at station 27.It shown that Xiamen Waters is the typical subtrophical water with high kg values. Size-fractionated results show that in summer microzooplankton have a preferential grazing on microphytoplankton at station 18, but was not at station 27. Picoeukaryotes were counted by a flow cytometry before and after dilution incubation and kg values at station 18 were estimated (2.00) d~(-1)1.02 d~(-1) for spring and 1.52 d~(-1)0.96 d~(-1) for summer.国家重点基础研究发展规划(973)资助项目(G1999043706

Distribution Features and Speciation of Heavy Metals in Surface Sediments of Main Mangrove of China

利用ICP-MS分析了我国红树林主要分布区表层沉积物的As含量和形态,阐明As的分布及其形态特征.结果表明,表层沉积物中w(As)为3.14～19.16mg/g,平均值为8.14mg/g.表层沉积物中w(As)与w(Fe),w(Mn),pH,w(有机质),粉粒和黏粒所占比例呈显著或极显著正相关.表层沉积物中的As主要以残渣态存在,其次为有机质-硫化物结合态.在整个研究区域,As的5种形态在总量中的所占比例:可交换离子态为14.40%,碳酸盐结合态为1.41%,铁锰氧化物结合态为2.16%,有机质-硫化物结合态为30.40%,残渣态为50.65%.可交换离子态所占比例与w(有机质)和pH呈极显著正相关.有机质-硫化物结合态所占比例与盐度、黏粒和粉粒所占比例呈显著或极显著正相关.残渣态所占比例与盐度、粉粒和黏粒所占比例呈极显著正相关.Arsenic contents in surface sediments collected from mangrove were analyzed with a PE DRC-e ICP-MS,and the distribution and species of As were identified.The results showed that As content ranged from 3.14～19.16 mg/g,with an average content of 8.14 mg/g.As content correlated well and positively with the contents of Fe and Mn,pH,organic content,silt and clay.Residual As was the primary species,and organic and sulfide As were the secondary species in the surface sediments.Among five As species,the exchangeable As accounted for 14.40%,carbonate As accounted for 1.41%,Fe-Mn oxides As accounted for 2.16%,organic-sulphide As accounted for 30.40%,and residual As accounted for 50.65%.Exchangeable As positively correlated with organic content and pH significantly.Organic-sulfide As and residual As positively correlated with salinity,silt and clay significantly.国家自然科学基金项目(40676064,30530150

Preliminary Study on the Distribution and Impact Factors of Methylmercury in Surficial Sediments from Main Mangrove Wetlands of China

通过对海南、广东、广西、福建的8个主要红树林地区沉积物中甲基汞以及环境因子的研究,分析了红树林生态系统中甲基汞的分布及其汞的甲基化作用.结果表明:1沉积物中总汞和甲基汞的含量分布并不一致.中国主要红树林区海南(三亚、东寨港)、广东(特呈岛、雷州、高桥、福田)、广西(大冠沙)、福建(浮宫)表层沉积物中甲基汞含量分别为(0.24±0.04)、(0.58±0.27)、(0.52±0.23)、(1.56±0.49)、(0.50±0.25)、(1.21±0.36)、(1.86±1.04)和(0.47±0.16)ng.g-1.甲基汞含量有很明显的地域区别,其含量顺序为大冠沙>雷州>福田>东寨港>特呈岛>高桥>浮宫>三亚.工业和养殖业输入的汞和有机质显著增加了沉积物中甲基汞水平.对比世界其他河口湿地,我国红树林湿地沉积物中的甲基汞污染较为严重.2红树林沉积物的甲基化比率介于0.11%~7.13%.甲基化比率顺序由大到小为大冠沙>特呈岛>雷州>福田>高桥>东寨港>三亚>浮宫.甲基化比率与砂粒显著正相关(P三亚>高桥>东寨>福田>大冠沙.各环境因子对微生物数量的影响无显著差异.沉积物中Srb的含量介于1.73x104~4.92x106Cfu/g,福田>浮宫>东寨港>三亚>高桥>大冠沙.高有机废水是导致沉积物中Srb含量增高的主要原因.沉积物类型对Srb在沉积物表层的分布也有较大影响.甲基汞和环境因子之间并没有明显的相关性,外源输入是我国红树林湿地沉积物中的甲基汞污染的主要原因.Total mercury(THg),methylmercury(MeHg) and environmental factors were determined to study distributions of MeHg and Hg methylation in the sediments from 8 main mangrove areas of China.The results showed that it was not consistent for distributions of THg and MeHg in sediments.Concentrations of MeHg in sediments from Sanya,Dongzhaigang(Hainan Province),Techengdao,Leizhou,Gaoqiao,Futian(Guangdong Province),Daguansha(Guangxi Autonomous Region),Fugong(Fujian Province) were(0.24 ± 0.04),(0.58 ± 0.27),(0.52 ± 0.23),(1.56 ± 0.49),(0.50 ± 0.25),(1.21 ± 0.36),(1.86 ± 1.04),(0.47 ± 0.16) ng.g-1 respectively.There were regional difference in MeHg contents which decreased in the order of Daguansha > Leizhou > Futian > Dongzhaigang > Techengdao > Gaoqiao > Fugong > Sanya.Input of Hg and organic matter from industry and aquiculture may lead to high level of MeHg.Compared with sediments from other estuaries of the world,serious pollution of MeHg was found in mangrove sediments of China.② % MeHg in mangrove sediments ranged from 0.11% to 7.13%,which decreased in the order of Daguansha > Techengdao > Leizhou > Futian > Gaoqiao > Dongzhaigang > Sanya > Fugong.There was significantly positive correlation between % MeHg and sandy fraction(p Sanya > Gaoqiao > Dongzhaigang > Futian > Daguansha.Sulfate-reducing bacterium(SRB) ranged from 1.73 × 104 to 4.92 × 106 CFU/g,SRB decreased in the order of Futian > Fugong > Dongzhaigang > Sanya > Gaoqiao > Daguansha.Wastewater with high organic matters leads to high SRB.The types of surface sediments also had a great impact on the amount of SRB.There was no significant correlation among MeHg and environmental factors,which indicated that exogenous input is the main cause of MeHg pollution in mangrove sediments.国家自然科学基金项目(40676064;30530150);中国科学院地球化学研究所环境地球化学国家重点实验室项

Heavy metals contamination in fish from coral reef ecosystem and ecology risk evaluation

为研究海南珊瑚礁区重金属的污染现状,选择鱼类为污染指示物,测定珊瑚礁区的5种鱼体中Cr、Mn、Cu、zn、AS、Pb和Hg 7种重金属的含量,并采用单因子污染指数法(PI)对重金属的污染状况进行了风险评价。研究结果显示,不同鱼类对同种重金属元素的富集能力存在较大差异,同种鱼对不同重金属元素的富集能力也存在差异。珊瑚礁区鱼类重金属的污染程度由强到弱的顺序为:Cr>AS>Mn>Hg>zn>Cu>Pb;鱼类的鳃和内脏器官比肌肉更容易蓄积重金属。珊瑚礁区生物富集作用最明显的为Cr和AS。PI结果表明海南珊瑚礁区鱼体重金属Cr的污染严重,AS中度污染,其他重金属基本无污染或轻度污染。To study the pollution status quo of heavy metals in coral reef ecosystem in Hainan Island,concentrations of heavy metals including Cr,Mn,Cu,Zn,As,Pb,and Hg in wild fish were determined.Single factor pollution index(Pi) was employed to evaluate the heavy metal pollution level.The results showed that enriched degree of the heavy metals in fish can be ranked from high to low as Cr>As>Mn>Hg>Zn>Cu>Pb;heavy metals prefer to be accumulated in gill and viscera.Obvious bioaccumulation of Cr and As in fish of coral reef ecosystem was observed.Pi indicated that coral reef ecosystem in Hainan Island has been heavily polluted by Cr and moderately polluted by As.Other metals have shown no pollution or slight pollution.中国博士后科学基金(2012M510201); 中国科学院百人计划资助项目(2060299); 中国科学院南海海洋研究所知识创新工程领域前沿项目(50601-31); 王宽诚教育基金会对本工作的资