海洋红藻鸭毛藻化学成分及抗氧化活性的研究

本论文采用DPPH（αα-二苯基-β-苦味酰自由基）自由基清除法和β-胡萝卜素-亚油酸氧化法对采自青岛沿海的28种海藻的粗提物进行了抗氧化活性筛选，以2,6-二叔丁基-4-甲基苯酚(BHT)、没食子酸(GA)和抗坏血酸(AscA)作为阳性对照。结果发现大多数海藻都表现了不同程度的抗氧化活性。其中，鸭毛藻Symphyocladia latiuscula的抗氧化活性最强。 鸭毛藻粗提物的乙酸乙酯相在两种方法中都表现了最强的抗氧化活性，乙酸乙酯相通过VLC被进一步分为7个组分(F1–F7)。其中F1对DPPH自由基的清除率最强，而在β-胡萝卜素-亚油酸实验中F4的抗氧化活性最强。 另外，还测定了粗提物、各相和各组分的总酚含量和还原能力。其中28种海藻粗提物的总酚含量变化范围为0.10到8.00 mg没食子酸/g海藻干重，还原能力变化范围为0.07到11.60mg抗坏血酸/g海藻干重。统计分析发现，对于粗提物和各相，抗氧化活性和总酚含量以及和还原能力都存在很强的正相关。这些结果将有助于进一步分析抗氧化活性强的海藻，从而确定活性原理。 由于鸭毛藻的抗氧化活性最强，所以对它的化学成分做进一步的调查。采用硅胶柱层析、制备薄层层析、凝胶Sephadex LH-20柱层析、反相硅胶柱层析、半制备HPLC及重结晶等手段分离得到19个化合物。运用各种现代波谱技术（IR、UV、ESI-MS、EI-MS、FAB-MS、HR-FAB-MS、1D-NMR、2D-NMR等）鉴定了它们的结构，其中包括4个新化合物：化合物S1 1-(2,3,6-三溴-4,5-二羟基苄基)-四氢吡咯-2-酮、化合物S2 1,2-双(2,3,6-三溴-4,5-二羟基苯基)乙烷、化合物S3 6-(2,3,6-三溴-4,5-二羟基苄基)-2,5-二溴-3,4-二羟基苄甲醚和化合物S4 2,3,6-三溴-4,5-二羟基苄甲砜，以及5个已知化合物和10个首次从鸭毛藻中报道的化合物。 分离到的溴酚化合物S1-S10具有显著的DPPH自由基清除活性，其IC50值在8.1-24.7 µM之间，且它们的活性是BHT（IC50 = 81.8 µM）的3.3到10倍左右。初步的构-效关系研究发现，分子中的羟基数目与活性有直接关系。

基于微波图像的辽东湾海冰典型要素信息提取

业务化海冰遥感监测的要素主要包括海冰类型、海冰厚度和海冰范围（冰缘线）。本文针对辽东湾海冰的特点，结合星载合成孔径雷达（SAR）、机载微波辐射计（ABMR）和星载微波辐射计遥感图像观测辽东湾海冰，发展海冰要素探测算法，提取海冰类型、海冰厚度和冰缘线信息。 海冰类型SAR信息提取方面，首先分析了双极化ENVISAT ASAR数据不同极化方式的海冰探测能力。然后利用SAR图像，结合同步TM数据和航空照片，开展辽东湾地区不同类型海冰的电磁特性研究。研究结果表明，SAR图像可较好地区分沿岸固定冰、平整冰和碎冰堆积区，但在探测初生冰方面并不可靠，探测结果与海冰生长阶段以及海冰周围环境条件有关。根据SAR图像中海冰类型的分析，将PCNN神经网络用于海冰SAR图像的分割和海冰分类，并对PCNN做了简化和改进。经SAR图像分类结果测试，简化和改进后的PCNN可较好地区分SAR图像中的海冰类型。通过分析了PCNN网络各参数对SAR图像分割结果的影响，指出了各参数的取值范围，并在此基础上建立了基于PCNN神经网络的海冰SAR图像半自动分类判读系统。 海冰厚度机载微波辐射计信息提取方面，推导了非相干模式的ABMR海冰厚度反演模型，并首次得到了模型中高阶亮温辐射项的计算表达式。通过对模型的分析，指出ABMR只能测量一定范围内的海冰厚度。其中，最大海冰探测厚度不仅决定于ABMR的波长，而且还受到仪器精度的限制；最小海冰探测厚度只与仪器的波长有关。在此基础上，定量计算了我国几种常用波长ABMR的海冰厚度探测范围。并结合辽东湾海冰冰情等级，指出适合不同海冰冰情等级的ABMR的选择。最后分析了海冰厚度反演模型的影响因素和模型的适应范围。 海冰边缘线星载微波辐射计信息提取方面，首次将PSSM算法用于AMSR数据，提取辽东湾海冰边缘线信息，可得到空间分辨率为2.5km、重复周期为1d的辽东湾海冰边缘线信息。通过提取结果与Jason-1高度计和SAR探测海冰边缘线的比较，验证了PSSM方法探测辽东湾海冰边缘线的有效性。 论文的最后对全文做了总结，并提出和讨论了需要进一步开展的工作。

调控文蛤幼虫变态的肾上腺素能受体类型及幼虫发育中神经和肌肉的变化

大部分贝类幼虫在发育过中要经历从浮游生活到底栖生活的变化过程，同时形态结构也要经历巨大的变化，这个过程称为变态。 变态是文蛤幼虫发育过程中非常重要的一个阶段。 药理学和细胞免疫学证据表明β肾上腺素样受体在文蛤幼虫变态过程中有重要作用。药理学实验分别采用了几种儿茶酚胺类受体的激动剂和抑制剂来处理幼虫，检验它们在幼虫变态过程中的作用。结果表明，在10μM和100μM的浓度下，肾上腺素(AD)和去甲肾上腺素(NA)中能够显著提高幼虫的变态率(p<0.05)。10μM和100μM浓度的AD能够提高幼虫变态率30%左右。10μM和100μM浓度的NA能分别提高幼虫变态率35.3%和27.6%。10μM的β受体激动剂－isoproterenol也能够显著的提高幼虫的变态率30%(p<0.05)，但是α受体激动剂－phenylephrine在0.1μM到100μM的浓度范围内不能显著提高幼虫的变态率(p>0.05)。而且，1μM的β受体抑制剂－propanolol能显著的抑制AD或NA提高幼虫变态率的作用(p<0.05)；但是α受体抑制剂－prazosin对AD或NA提高幼虫变态率没有显著性影响(p>0.05)。 此外本文还利用整装免疫细胞化学的方法进一步研究了文蛤幼虫不同发育阶段，神经系统和β肾上腺素样受体的发育情况。 幼虫的神经系统在担轮幼虫时期(受精后18h)开始发育，这时还不能检测到β肾上腺素受体。面盘幼虫时期(受精后1d)具备了顶神经节、脑神经节和脏神经节组成的中枢神经系统，在口附近有一些外周神经。β肾上腺素受体在受精后24h首次出现在面盘幼虫的顶神经节和脑神经节，分别命名为AR(apical receptor)和CR1(cerebral receptor 1)。 在受精后5d顶神经节已经检测不到。脑神经节和脏神经节由腹部向背部迁移，口的背腹两侧都出现了一些神经元。并且脏神经节周围也出现了一些神经细胞。AR在受精后3d就检测不到了。同时在CR1的后部新出现了一些β肾上腺素受体，命名为CR2。此后CR2发育迅速，在受精后5d就和CR1差不多大小。并且在CR1和CR2之间还出现了很多小的阳性信号。 变态过程中中枢神经系统中顶神经节消失了，并且出现了足神经节。另外，外套膜上出现了更多的外周神经。除了在稚贝的脑神经节和脏神经节外，在足、外套膜和水管上都有β肾上腺素受体存在。成体的鳃、足、心脏、水管、唇掰和外套膜上也有β肾上腺素受体分布。 变态信号传递到靶器官后，文蛤幼虫在形态结构和生态习性上开始了快速巨大的变化。其中幼虫的肌肉系统是变化最大的系统，并且直接与文蛤运动、摄食等习性转变相关。本文采用免疫组化的方法对文蛤幼虫肌肉系统的发育进行了研究。结果表明，文蛤幼虫具有由幼虫收缩肌、面盘收缩肌和闭壳肌组成的十分复杂的肌肉系统。幼虫收缩肌和前闭壳肌最早出现于担轮幼虫阶段(受精后18h)。孵化后幼虫的肌肉系统迅速发育，受精后22h幼虫的肌肉系统基本发育完全，并一直维持到变态前。变态过程中幼虫收缩肌和面盘收缩肌逐渐萎缩消失。同时，足收缩肌、后闭壳肌和外套膜肌肉等稚贝的肌肉系统快速形成。变态后稚贝幼虫收缩肌和面盘收缩肌完全消失，其肌肉系统由前后闭壳肌、足收缩肌和外套膜肌肉组成。

两种红树林植物海漆和海桑化学成分研究

本论文对两种红树林植物海漆 (Excoecaria agallocha L.) 和海桑（Sonneratia caseolaris L.）的化学成分进行了系统研究。 采用常规的硅胶柱层析、制备薄层层析、凝胶 Sephadex LH-20 柱层析、MCI柱层析、反相硅胶柱层析、半制备型 HPLC 以及重结晶等手段，从海漆 (Excoecaria agalloch L. ) 中分离得到 40 个化合物，从海桑（Sonneratia caseolaris L.）中分离得到 30 个化合物。利用各种现代波谱技术 (IR、UV、ESI-MS、EI-MS、1D-NMR、2D-NMR等) 及其化学物理性质，确定了海漆中 32 个化合物的结构，其中包括 1 个新的三萜天然产物以及 15 个首次从海漆中报道的化合物；确定了海桑中 27 个化合物的结构，其中包括 1 个新化合物和一个首次报道其碳谱数据的化合物。本文为首次报道海桑的化学成分研究。 对海漆和海桑粗提物及分离得到的部分化合物进行了抗肝癌细胞毒活性筛选，化合物S22表现出较强活性，其IC50为2.8 μg/mL；海漆和海桑粗提物及其它部分单体化合物只表现出微弱活性；阳性对照丝裂霉素C的IC50为1.1 μg/mL。 对分离得到的部分样品还进行了抗菌活性测试，各样品在测试浓度下对测试菌均未表现出明显的抗菌活性。 首次研究了海漆挥发性成分及其季节性变化。利用水蒸汽法提取了不同季节海漆的挥发性成分，通过GC-MS鉴定其化学组成，发现脂肪酸、二萜和倍半萜是海漆挥发性成分的主要组成，不同季节的挥发性成分差异较大。

两株海藻内生真菌次生代谢产物及其生物活性研究

海洋微生物拥有丰富多样的次生代谢途径，其中海洋生物内生真菌次生代谢产物研究日益受到天然产物化学界的重视。本论文以菌丝体生物量、发酵产物重量、抗菌与细胞毒活性、薄层色谱分析结果以及高效液相色谱分析结果等为评价依据对采自青岛沿海的13株海藻内生真菌在四种液体培养基上的静置发酵产物进行了综合评价，并从中选择了黑曲霉Aspergillus niger EN-13（分离自褐藻囊藻Colpomenia sinuosa）和杂色曲霉A. versicolor EN-7（分离自褐藻鼠尾藻Sargassum thunbergii）两株真菌进行了30升规模发酵（分别采用GPYM培养基和PDB培养）和化学成分的研究，对分离得到的大部分化合物进行了初步的生物活性筛选。 发酵提取物采用常规的硅胶柱层析、反相硅胶柱层析，凝胶Sephadex LH-20柱层析、制备薄层层析、半制备高效液相色谱以及重结晶等分离手段，得到单体化合物。利用各种现代波谱技术(IR、UV、EI-MS、FAB-MS、HR-ESI-MS、1H-NMR、13C-NMR、DEPT、1H-1H COSY、HSQC、HMBC等)并结合化学方法从两种菌株发酵提取物中鉴定了55个化合物的结构。其中从菌株A. niger EN-13分离鉴定了31个化合物，发现9个新化合物，包括2个鞘酯类化合物（AN-1~2）、3个萘并-γ-吡喃酮类化合物（AN-3~5）、3个苯乙基取代的α-吡喃酮类化合物（AN-17, AN-19~20）和1个甾体Diels-Alder加成产物（AN-21），另有1个新的天然环二肽（AN-27）被分离鉴定；从菌株A. versicolor EN-7分离鉴定了24个化合物，发现2个新化合物，为蒽醌AV-12与AV-17，另外，从前一菌株（A. niger EN-13）中鉴定的2个新鞘酯类化合物（AN-1~2）在A. versicolor EN-7中也被再次分离到。 对大部分单体化合物进行了抗菌活性、DPPH自由基清除活性和细胞毒活性测试。结果显示新化合物AN-1、AN-5和AN-20具有弱或中等强度的抑制白色念珠菌生长的活性，AN-4、AN-5、AN-21显示了弱或中等强度的抑制黑曲霉生长的活性，AV-12、AV-17显示了弱的抑制大肠杆菌生长的活性。在DPPH自由基清除活性筛选中，AN-5显示了中等强度的活性，其EC50为109.3 mM，与阳性对照BHT相近（EC50为81.8 mM）。其它部分已知化合物在抗菌和DPPH自由基清除活性的筛选中也显示了弱或中等强度的活性。在针对人肝癌细胞株SMMC-7721和人肺腺癌细胞株A549的体外细胞毒活性筛选中，所测样品均未显示显著活性。

Bromophenols from the red alga Rhodomela confervoides

Six new bromophenols, 3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)pyrocatechol (1), 2,2',3-tribromo-3',4,4',5-tetrahydroxy-6'-hydroxymethyldiphenylmethane (2), 2,2',3-tribromo-3',4,4',5-tetrahydroxy-6'-ethyloxymethyldiphenylmethane (3),(+/-)-2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde (4), (+/-)-2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde dimethyl acetal (5), and 3-bromo-4,5-dihydroxybenzoic acid methyl ester (6), together with eight known bromophenols, 3-bromo-4,5-dihydroxybenzaldehyde (7), 2,3-dibromo-4,5-dihydroxybenzyl alcohol (lanosol, 8), 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (9), 2,3-dibromo-4,5-dihydroxybenzyl ethyl ether (10), 2,3-dibromo-4,5-dihydroxybenzylaldehyde (11), bis(2,3-dibromo-4,5-dihydroxybenzyl) ether (12), 3-bromo-4-(2,3-dibromo-4,5-dihydroxybenzyl)-5-methoxymethylpyrocatechol (13), and 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxydiphenyl methane (14), were isolated from the red alga Rhodomela confervoides. Their structures were elucidated by chemical and spectroscopic methods including IR, HRFABMS, and 1D and 2D NMR techniques.

Cadinane Sesquiterpenes from the brown alga Dictyopteris divaricata

Seven new cadinane sesquiterpenes, (-)-(1R,6S,7S,10R)-1-hydroxycadinan-3-en-5-one (1), (+)-(1R,5S,6R,7S, 10R)-cadinan-3-ene-1,5-diol (2), (+)-(1R,5R,6R,7S,10R)-cadinan-3-ene-1,5-diol (3), (+)-(1R,5S,6R,7S,10R)-cadinan-4(11)-ene-1,5-diol (4), (+)-(1R,5R,6R,7R,10R)-cadinan-4(11)-ene-1,5,12-triol (5), (-)-(1R,4R,5S,6R,7S, 10R)-cadinan-1,4,5-triol (6), and (-)-(1R,6R,7S,10R)-11-oxocadinan-4-en-1-ol (7), together with nine known compounds were isolated from the brown alga Dictyopteris divaricata. The structures of the new natural products, as well as their absolute configuration, were established by means of spectroscopic data including IR, HRMS, 1D and 2D NMR, single-crystal X-ray diffraction, and CD. All compounds were inactive against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), breast cancer (MCF-7), hepatoma (Bel7402), and colon cancer (HCT-8) cell lines.

Minor sesquiterpenes with new carbon skeletons from the brown alga Dictyopteris divaricata

Five minor sesquiterpenes (1-5) with two novel carbon skeletons, together with a minor new oplopane sesquiterpene ( 6), have been isolated from the brown alga Dictyopteris divaricata. By means of spectroscopic data including IR, HRMS, 1D and 2D NMR, and CD, their structures including absolute configurations were assigned as (+)-(1R, 5S, 6S, 9R)3- acetyl-1-hydroxy-6-isopropyl-9-methylbicyclo[4.3.0] non-3-ene ( 1), (+)-(1R, 3S, 4S, 5R, 6S, 9R)-3-acetyl-1,4-dihydroxy-6- isopropyl-9-methylbicyclo[4.3.0] nonane (2), (+)-(1R, 3R, 4R, 5R, 6S, 9R)-3-acetyl-1,4-dihydroxy-6-isopropyl-9-methylbicyclo[ ;4.3.0] nonane ( 3), (+)-(1S, 2R, 6S, 9R)-1-hydroxy-2-(1-hydroxyethyl)-6-isopropyl-9-methylbicyclo[4.3.0] non-4-en-3-one (4), (-)-( 5S, 6R, 9S)-2-acetyl-5-hydroxy-6-isopropyl-9-methylbicyclo[4.3.0] non-1-en-3-one ( 5), and (-)-( 1S, 6S, 9R)- 4-acetyl- 1-hydroxy-6-isopropyl-9-methylbicyclo[ 4.3.0] non-4-en-3-one ( 6). Biogenetically, the carbon skeletons of 1-6 may be derived from the co-occurring cadinane skeleton by different ring contraction rearrangements. Compounds 1-6 were inactive (IC50 > 10 mu g/mL) against several human cancer cell lines.

Norsesquiterpenes from the brown alga Dictyopteris divaricata

Three bisnorsesquiterpenes (1-3) with novel carbon skeletons and a norsesquiterpene (4) have been isolated from the brown alga Dictyopteris divaricata. By means of spectroscopic data including IR, HRMS, 1D and 2D NMR techniques, single-crystal X-ray diffraction, and CD, their structures including absolute configurations were proposed as (+)-1R,6S,9R)-1-hydroxyl-6-isopropyl-9-methylbicyclo[4.3.0]non-4-en3-one (1), (-)-(1S,6S,9R)-1-hydroxyl-6-isopropyl-9-methylbicyclo[4.3.0] non-4-en-3-one (2), (+)-(5S,6R,9S)5-hydroxyl-6-isopropyl-9-methylbicyclo [4.3.01 non-1-en-3-one (3), and (-)-(1R,7S,10R)-1-hydroxy-1lnorcadinan-5-en-4-one (4). Biogenetically, the carbon skeleton of 1-3 may be derived from the co-occurring cadinane skeleton by ring contraction and loss of two carbon units, and compound 4 from the oxidation of cadinane derivatives. Compounds 1-4 were inactive (IC50 > 10 mu g/mL) against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), breast cancer (MCF-7), hepatoma (Bel7402), and colon cancer (HCT-8) cell lines.

Bromophenol derivatives from the red alga Rhodomela confervoides

Eight new bromophenol derivatives, 2,3-dibromo-4,5-dihydroxybenzyl methyl sulfoxide (1), 4-(2,3-dibromo-4,5-dihydroxyphenyl)-3-butene-2-one (2), 2-(3-bromo-5-hydroxy-4-methoxyphenyl)-3-(2,3-dibromo-4,5-dihydroxyphenyl)propionic acid (3), 2-(3-bromo-5-hydroxy-4-methoxyphenyl)-3-(2,3-dibromo-4,5-dihydroxyphenyl)propionic acid methyl ester (4), 2-phenyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propionic acid (5), 4'-methoxy-2",3',3"-tribromo-4",5',5"-trihydroxydiphenylacetic acid (6), and 3-bromo-5-hydroxy-4-methoxyphenylacetic acid (7) and its methyl ester (8), together with a known bromophenol, 3-bromo-5-hydroxy4-methoxybenzoic acid (9), were isolated from the red alga Rhodomela confervoides. Their structures were elucidated by spectroscopic methods including IR, EIMS, FABMS, ESIMS, HRFABMS, HRESIMS, 1D and 2D NMR, and single-crystal X-ray structure analysis. Compounds 1-4, 8, and 9 were found inactive against several human cancer cell lines and microorganisms.

Sesquiterpenes from the Marine Red Alga Laurencia saitoi

Together with five known sesquiterpenes, EtOH extraction of Laurencia saitoi yielded four new compounds, including three sesquiterpenes and one norsesquiterpene derivative. Their structures and relative configurations were elucidated by spectroscopic methods, including 1D- and 2D-NMR (H-1,H-1-COSY, HMQC, HMBC, and NOESY), as well as low- and high-resolution mass-spectrometric analyses.

Two new bromoindoles from red alga Laurencia similis

Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis. On the basis of chemical and spectroscopic methods (including 1D and 2D NMR technique), their structures have been elucidated as 2,2',5,5',6,6'-sixibromo-3, 3'-bi-1H-indole and 3, 5-dibromo-1-methylindole, respectively. (C) 2008 Xiao Bin Zhu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

A novel polyhydroxyl sterol from Asterina pectinifera

A novel polyhydroxyl sterol ( 1) along with one known polyhydroxyl sterol (2), and two known monoglycosides, asterosaponin P-1 (3) and its desulfated monoglycoside (4), have been isolated from the whole bodies of a common Pacific starfish Asterina pectinifera. The structure of the new polyhydroxyl sterol was determined as 15beta, 16beta-isopropylidenedioxy-5alpha-cholestane-3beta, 4beta, 6alpha, 7alpha, 8,26-hexaol by spectroscopic methods, including FABMS, HR-FABMS, 1D and 2D NMR techniques.

A new sesquiterpene-substituted benzoic acid from the brown alga Dictyopteris divaricata.

A new sesquiterpene-substituted benzoic acid has been isolated from the brown Alga Dictyopteris divaricata Okam.. Its structure was elucidated as 3-[(2-hydroxy-2,5,5,8a-tetramethyldecahydro-1-naphthalenyl)methyl]-4-hydroxybenzoic acid, named dictyvaric acid on the basis of spectroscopic methods including IR, HRFABMS, 1D and 2D NMR techniques.

Two new bromophenols from red alga Rhodomela confervoides

Two new bromophenols were isolated from Rhodomela confervoides. Their structures were elucidated as 2, 2', 3-tribromo-3', 4, 4', 5-tetrahydroxy-6'-hydroxymethyldiphenylmethane and 2, 2', 3-tribromo-3', 4, 4', 5-tetrahydroxy-6'-ethyloxymethyldiphenylmethane by spectroscopic methods including IR, HREIMS, 1D and 2D NMR techniques.