中国软珊瑚化学成分的研究（二十五）：一种新的二萜甙Lemnabourside的结构

从中国软珊瑚Lemnalia bournei中分离到一种新的二萜甙类化合物,命名为波伦鳞花甙(Lemnabourside)。它是二萜与葡萄糖以一种新型甙链相连的化合物。通过波谱数据、化学降解和萜类的生源规则推导出它的化学结构。     

软珊瑚化学成分及其生理活性研究

就中国南海处于亚热带地区的软珊瑚的化学成分(包括萜类、甾醇类、鲨肝醇、嘧啶类和含氮化合物等生理活性物质)作了详细的介绍,并对其相应结构的抗菌、抗炎、抗肿瘤、抗癌以及明显的抗心律失常和心肌缺血作用作了论述。     

中国南海软珊瑚Sinularia inexplicita化学成分研究(Ⅰ)羟基化合物的结构研究

对采自我国南海软珊瑚Ｓｉｎｕｌａｒｉａｉｎｅｘｐｌｉｃｉｔａ的化学成分进行了系统的研究，利用柱层析分离得到３个次生代谢产物Ⅰ，Ⅱ和Ⅲ．经元素分析和波谱分析确定它们的结构分别为柳珊瑚甾醇，鲨肝醇和长链十六碳酸酯．     

Sinularia sp.中化学成分的分离与结构鉴定

利用硅胶色谱、凝胶色谱等分离方法从软珊瑚Sinularia sp.中分离得到6种化学成分.通过一维核磁共振波谱、二维核磁共振波谱和质谱等分析方法对化合物进行结构解析,确定为西松烷二萜类成分:lobocrassolide,lobo-hedleolide,(7Z)-lobohedleolide和2-epi-11Z-lobohedleolide;邻笨二甲酸酯类成分:1,2-benzenedicarboxylic acid di-isobutyl ester;甾醇类成分:ergosta-5-en-3β-ol.其中4种西松烷二萜类化合物为首次从该样品中获得.     

南海疣状柳珊瑚中八放二萜类化学成分研究

【目的】为了证明疣状柳珊瑚(Verrucella umbraculum)中的主要化学成分是八放二萜类化合物,并获得结构新颖的八放二萜类化合物。【方法】采用硅胶柱色谱、Sephadex LH-20和反相半制备HPLC等方法分离化合物,根据波谱数据以及文献对照方法,确定其结构。【结果】从疣状柳珊瑚分离得到10个八放二萜类化合物,鉴定为junceellin A(1)、renillafoulin A(2)、praelolide(3)、(-)-11α,20α?epoxy-4-deacetyljunceellolide(4)、umbraculolide A(5)、umbraculolide C(6)、junceellolide A(7)、13-deacetylnui-inoalide A(8)、erythrolide T(9)、erythrolide U(10)。【结论】化合物3~10为首次从疣状柳珊瑚中分离得到,丰富了该属柳珊瑚中的化学成分类型。     

南海豆荚软珊瑚Lobophytum sp.化学成分研究基金项目:国家自然科学基金资助项目(29802010);广东省博士启动基金资助项目(984147)

从广西省北海水域采集的未定名豆荚软珊瑚（Ｌｏｂｏｐｈｙｔｕｍ ｓｐ．）乙酸乙酯提取物中,分离得到３个化合物;经ＩＲ,ＭＳ,ＮＭＲ和２Ｄ－ＮＭＲ等波谱方法,鉴定出１种化合物为已知物鲨肝醇,另２种化合物为ｇｕａｎｉｄｉｎｅ类生物碱化合物,这是首次从软珊瑚中分离到这一类生物碱。     

中国软珊瑚化学成分的研究(十七)——戚氏豆荚珊瑚(Lobophyfum chevalieri)的研究

从中国软珊瑚Lobophytum chevalieri分离出15个结晶化合物,本文对四羟基甾单酯和柳珊瑚甾醇二个甾醇化合物,进行了波谱数据和化学分析,并推导出它们的结构.     

中国南海软珊瑚Sinularia inexplicita化学成分研究

对采自我国南海软珊瑚Ｓｉｎｕｌａｒｉａ ｉｎｅｘｐｌｉｃｉｔａ的化学成分进行了系统的研究，利用柱层析分离得到了３个次生代谢产物Ⅰ，Ⅱ和Ⅲ，经元素分析和波谱分析确定它们的结构分别为柳珊瑚甾醇，鲨肝醇和长锭十六碳酸酯。     

丛柳珊瑚Euplexaura rhipidalis中细胞毒活性二萜成分分析

为了寻找结构新颖的海洋活性成分,对一种采自中国西沙海域丛柳珊瑚Euplexaura rhipidalis进行分离和纯化,并对获得的西松烷二菇化合物的抗肿瘤活性进行筛选,以探明该种丛柳珊瑚的活性组成成分.先利用正反相硅胶柱层析、Sephadex LH-20凝胶柱层析和半制备HPLC等方法进行分离和纯化,再利用NMR、MS等波谱方法,并与文献对照确定了3个高氧化度的西松烷二萜类化合物,分别为eorulloidolide A（1）,（1R,3S,4S,7E,11E）-3,4-epoxycembra-7,11,15-triene（2）,（-）-corulloidolide E（3）;细胞毒活性模型评价结果发现,化合物3表现了较强的细胞毒活性,对5种癌细胞肝癌HepG2,Hep3B,乳腺癌阿霉素耐药株MCF-7/ADR,前列腺癌PC-3he,结肠癌HT-116的IC50值都低于10 μg/mL.表明西松烷二萜类化合物是该丛柳珊瑚E.rhipidalis的主要活性化合物类型之一.     

中国南海软珊瑚Cladiella densa的化学成分研究

本文报道从软珊瑚Ｃｌａｄｉｅｌｌａｄｅｎｓａ中分离出正三十一碳醇，鲨肝醇和柳珊瑚甾醇３个化合物，正三十一碳醇是在软珊瑚中首次发现。     

High-precision U-series dating of Holocene corals from South China Sea by thermal ionization mass spectrometry (TIMS)

Using the isotopic diluting and thermal ionization mass spectrometric (TIMS) technique, the U-series dating procedure was established on the basis of measurement of national standard GBW04412. With this highly precise technique the Holocene corals from the South China Sea were dated. Comparison between this method and α-spectrometry was made. The results show that a thriving period of corals in the South China Sea appeared at 6 800-5 800 a BP, during which the paleosea level was the higher than at present in the Holocene.     

Long-chain branched/cyclic alkanes in recent sediment of Lake Fuxian and their environmental implications

Lake Fuxian is a large, deep, and oligotrophic freshwater lake. In recent sediment of this lake, a series of branched and cyclic alkanes, including branched alkanes with one or two quaternary carbon atoms （C2n compounds）, alkylcycloheptane, and alkylcyclohexane, were detected in high abundance. For each homolog of long-chain branched/ cyclic alkanes, molecules with only an odd or even carbon number were present in the sediment. The abundance vari- ation of each compound homolog corresponded to those of other compound homolog in the section, indicating the same origin of these compounds. The concentrations of long-chain branched/cyclic alkanes in the sediment profile exhibited variations similar to those of phytoplankton biomarkers, such as 3-methylJalkanes, short-chain odd carbon n-alkanes, hopene, polyunsaturated fatty acids, phytol, sterols, and long-chain alkyl diols, but slightly different from those of long-chain odd carbon n-alkanes, which are ubiquitous biomarkers for higher plants. Therefore, the Can compounds and long-chain cyclic alkanes in the lake sediment were most likely produced by algae and bacteria in the water, primarily, by the heterotrophic bacteria in the moderately oxygenated waters, which flourishing might be the results of specific water environments in Lake Fuxian.     

由担子菌产生的芳香物质及特性

通过担子菌的生物合成可产生许多芳香物质，其化学结构主要是芳香族化合物，萜烯类化合物，γ或δ－内酯以及脂肪醇、脂肪酮和脂肪酸酯。     

塔里木盆地煤显微组分显微傅里叶红外光谱特征及意义

应用显微红外光谱技术,对塔里木盆地侏罗纪煤中有代表性的3种组分角质体,镜质体、丝质体在不同热模拟温度下的结构组成变化特征进行了研究,结果表明：角质体结构组成中含有较丰富的长链脂族结构,而芳香结构和含氧官能团的含量则相对减少;与此相反,丝质体结构组成中芳香烃占绝对优势,而脂族结构含量则很少,镜质体结构组成介入体和丝质体之间,含有较多的短链脂族结构和芳香结构。据此推断,角质体具有高的生烃潜力,是一种倾油组分;镜质体生烃潜力中等,是一种倾气组分,但也可以生成一定数量的液态烃;丝质体生烃潜力很小,对煤成烃的贡献微不足道,另外,随热模拟温度的升高,3种组分中的脂族结构和含氧官能团都呈现明显的由强到弱的变化,而芳香结构比较稳定,在整个生烃热演化过程中则呈现芳环缩合度增加芳烃相对富集的趋势。由此说明,煤生烃过程主要是一种脂族结构和含氧基团不断脱落,芳香结构不断缩聚的过程。     

Interspecies and spatial diversity in the symbiotic zooxanthellae density in corals from northern South China Sea and its relationship to coral reef bleaching

Coral reef bleaching is usually characterized by expulsion of symbiotic zooxanthellae, loss of zooxanthellae pigmentation, or both. We collected 128 samples comprising 39 species of 21 genera of reef-building corals from Luhuitou and Xiaodonghai in Sanya of Hainan Island and Daya Bay of Guangdong Province, respectively, and analyzed the symbiotic zooxanthellae population density. The results show that： （1） the symbiotic zooxanthella density varies from 0.67×10^6 to 8.48×10^6 cell/cm^2, displaying significant interspecies variability, with branch corals usually having relatively less zooxanthellae （ranging from 0.67×10^6 to 2.47×10^6 cell/cm^2） than massive species （from 1.0×10^6 to 8.48×10^6 cell/cm^2）; （2） corals inhabiting within 4 m water depth have higher levels of symbiotic zooxanthellae than those living at the bottom （-7 m depth） of the reef area; （3） there is no discernable difference in the zooxanthellae density between corals from relatively high latitude Daya Bay （-22°N） and those from relatively low latitude Sanya （-18°N） at comparable sea surface temperatures （SST）; （4） in partially-bleached corals, the density of zooxanthellae shows the following order： healthy-looking part〉 semi-bleached part 〉 bleached part. Based on the above results, we suggest that （1） the zooxanthellae density difference between branching and massive coral species is the main cause that branching corals are more vulnerable to bleaching than massive corals. For example, symbiotic zooxanthellae levels are low in branching Acropora and Pocillopora corals and thus these corals are more susceptible to bleaching and mortality; （2） symbiotic zooxanthellae density can also be affected by environmental conditions, such as sediment loads, diving-related turbidity, and aquaculture-related nitrate and phosphate input, and their increase may reduce symbiotic zooxanthellae density in corals.     

Gemini表面活性剂的合成及性能

以二苯乙烷和长碳链脂肪酰氯为原料合成出Gemini磺酸表面活性剂,通过核磁氢谱和红外光谱对化合物的结构进行表征,测定了其水溶液的表面张力,得出其表面张力曲线,进而算出其他相关参数.3种Gemini表面活性剂的临界胶束浓度(CMC)值随烷基疏水碳链的增长而降低.与线性十二烷基苯磺酸钠(SDBS)相比,Gemini表面活性剂G12-2-12的C20值降低94.4%,CMC值降低91.3%.G12-2-12的饱和吸附面积(Amin)比对应单基表面活性剂的2倍降低27%,且Gemini表面活性剂在气液界面上排列更加紧密.     

Using the Acropora digitifera genome to understand coral responses to environmental change

Despite the enormous ecological and economic importance of coral reefs, the keystone organisms in their establishment, the scleractinian corals, increasingly face a range of anthropogenic challenges including ocean acidification and seawater temperature rise. To understand better the molecular mechanisms underlying coral biology, here we decoded the approximately 420-megabase genome of Acropora digitifera using next-generation sequencing technology. This genome contains approximately 23,700 gene models. Molecular phylogenetics indicate that the coral and the sea anemone Nematostella vectensis diverged approximately 500 million years ago, considerably earlier than the time over which modern corals are represented in the fossil record (～240 million years ago). Despite the long evolutionary history of the endosymbiosis, no evidence was found for horizontal transfer of genes from symbiont to host. However, unlike several other corals, Acropora seems to lack an enzyme essential for cysteine biosynthesis, implying dependency of this coral on its symbionts for this amino acid. Corals inhabit environments where they are frequently exposed to high levels of solar radiation, and analysis of the Acropora genome data indicates that the coral host can independently carry out de novo synthesis of mycosporine-like amino acids, which are potent ultraviolet-protective compounds. In addition, the coral innate immunity repertoire is notably more complex than that of the sea anemone, indicating that some of these genes may have roles in symbiosis or coloniality. A number of genes with putative roles in calcification were identified, and several of these are restricted to corals. The coral genome provides a platform for understanding the molecular basis of symbiosis and responses to environmental changes.     

红外光谱法研究油页岩及干酪根的生油能力

采用Lorentzian分峰拟合,A-C因子和含100%脂肪链的微晶石蜡为标准物质的方法对油页岩及去矿物油页岩干酪根红外吸收光谱进行了研究,分析了干酪根中各种烃的成分和含量.结果表明:油页岩及去矿物油页岩中有机质均为Ⅱ型干酪根;去矿物能使支链从干酪根主链上脱落,但去矿物程度不宜过大.随着去矿物程度加深,干酪根脂肪链含量、红外谱图中CH2与CH3吸收峰面积的比值和脂氢/芳氢面积比值先增大,后减小;油页岩经酸碱处理后,干酪根中脂肪链的含量可达到54.06%,CH2与CH3吸收峰面积的比值为7.11,脂氢和芳氢的面积比值为2.73.无机矿物质的去除使干酪根的生油潜力得到提高.     

α-羟基次膦酸酯的合成与性质

在碱催化的条件下，通过二甲基次膦酸酯与多种脂肪醛以及取代（非取代）芳香醛的加成反应，合成了９种标题化合物，其中８种为新化合物，通过ＩＲ，ＭＳ及＾１Ｈ ＮＭＲ等确认了它们的结构，并探讨了它们的波谱性质。     

有机化合物结构性能关系研究的新方法

根据分子拓扑学原理，用距离矩阵描述分子结构，用不同的因子标识分子中的原子种类，发展了一种适用于含杂原子分子体系结构性能关系研究的新方法．据此探讨了脂肪醚沸点与分子结构之间的关系，提出一个既能合理表征脂肪醚结构性能关系、又能预测沸点的定量关系式．