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在生物活性指导下,从一株来源于药用红树尖瓣海莲的内生真菌Penicillium sp.(J41221)中分离鉴定了6个化合物,包括4个四环三萜类化合物和2个甾醇类化合物,结构分别为:11-羰基-12α-乙酰氧基-4,4-二甲基-24-甲烯基-5α-胆甾-8,14-二烯-2α,3β-二醇(1),12α-乙酰氧基-4,4-二甲基-24-甲烯基-5α-胆甾-8-单烯-3β,11β-二醇(2),12α-乙酰氧基-4,4-二甲基-24-甲烯基-5α-胆甾-8,14-二烯-3β,11β-二醇(3),12α-乙酰氧基-4,4-二甲基-24-甲烯基-5α-胆甾-8,14-二烯-2α,3β,11β-三醇(4),啤酒甾醇(5)和(3β,5α,6β,22E)-6-甲氧基麦角甾-7,22-二烯-3,5-二醇(6).其中化合物1为首次从生物中获得,且1和2的波谱数据迄今未见任何报道.抗菌活性结果表明,化合物2和4对金黄色葡萄球菌、大肠杆菌和四联球菌均显示一定的抑制活性,最小抑菌浓度(MIC)分别为5和4.86μmol/L. 相似文献
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肉芝软珊瑚Sarcophyton sp中次生代谢产物的研究 总被引:2,自引:0,他引:2
从中国海南岛三亚附近海域采集的肉芝软珊瑚Sarcophyton sp中,分离得5个结晶化合物。通过化学和波谱方法鉴定出他们的结构分别是:24亚甲基胆甾-1α,3β,5α,6β-四醇(1);24-亚甲基胆甾14-烯-3β,6β-二醇(2);2.十六碳酰胺基-十八-4(E),8(E)-二烯-1,3-二醇(3);(2S,3S,5R)-2-十六碳酰胺基-十八-1,3,5-三醇(4);柳珊瑚甾醇(5)。生理活性试验表明,化合物1对人体鼻咽癌(CNE2)和胃癌(NGC-803)细胞有强抑制活性;化合物2对P-388肿瘤细胞有强抑制活性;柳珊瑚甾醇(5)有明显的抗心律失常和减慢心率等作用。 相似文献
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Nephthea属软珊瑚中19-羟基甾醇Nephalsterol A及B的结构测定 总被引:3,自引:0,他引:3
从南海软珊瑚Nephthea albida及N.tiexieral verseveldt中分离到2个含19-羟基的多羟基甾醇Nephalsterol A(1)及 B(2),通过波谱方法测定了1及2的结构依次为:24-亚甲基-胆甾-3β,5α,6β,19-四醇及24-亚甲基-胆甾-5-烯-3β,7β,19-三醇。 相似文献
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南海短足软珊瑚Cladiella sp.中两个新孕甾醇苷的分离 总被引:2,自引:0,他引:2
从短足软珊瑚Cladiella sp.中,分离得到3个甾类化合物:孕甾-5,20-二烯-3β-醇-3-O-α-L-吡喃岩藻糖苷(1)、孕甾-5,20-二烯-3β-醇-3-O-β-D-吡喃木糖苷(2)和(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(3),其中1和2为新化合物.孕甾醇苷具有抗早孕和抑制肿瘤细胞生长活性. 相似文献
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豆荚软珊瑚Lobophytum sp. 的次生代谢产物研究 总被引:4,自引:0,他引:4
从海南岛三亚海域采集的软珊瑚Labophytumsp.中分离得五个甾醇苷(1)~(5)。通过波谱分析,确定它们的化学结构依次为3'-O-乙酰基-4-O-[β-D-吡喃木糖苷]-孕甾-20-烯-3β,4α-二醇(1),4-O-[β-D-吡喃木糖苷]-孕甾-20-烯-3β,4α-二醇(2),4'-O-乙酰基-4-O-[β-D-吡喃木糖苷]-孕甾-20-烯-3β,4α-二醇(3),4'-O-乙酰基-4-O-[β-D-吡喃阿拉伯糖苷]-孕甾-20-烯-3β,4α-二醇(4)和4-O-[β-D-吡喃阿拉伯糖苷]-孕甾-20-烯-3β,4α-二醇(5),其中1为新化合物。体外细胞毒性实验表明:化合物(1),(2)和(5)对SKMG-4,Hep-G2和CNE2三种人体癌细胞具有抑制作用。 相似文献
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HEPT类化合物的QSAR研究 总被引:3,自引:0,他引:3
为定量结构/活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法(Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物(1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构/活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。 相似文献
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Emma Hocker 《Macromolecular Symposia》2006,238(1):16-21
Sweden's famous warship, Vasa, sank on her maiden voyage in August 1628, and remained on the bottom of Stockholm harbour for 333 years. Raised in 1961, she became the first large-scale wooden object to be treated with polyethylene glycol (PEG). In the summer of 2000 a number of acidic salt precipitations were noticed on the surface of the ship and on wooden artefacts in the storerooms. An international research project has been established to look into the causes of this problem and suggest possible re-treatments. Meanwhile projects are underway to monitor movements in the ship, to build a better support system, and to replace the thousands of iron bolts holding the structure together, while a sophisticated new climate system has recently been installed in the museum. 相似文献
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通过在LS55型荧光-磷光-发光分光光度计上加装液滴产生及调节附件,采用计算机采集与分析处理数据,成功地研制了双通道液滴光化学传感装置.利用葡聚糖凝胶对复合维生素B中不同组分的选择性吸附来达到分离与同时检测的目的,并将其用于复合维生素B药片的分析,取得了满意的结果. 相似文献
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The content of the fine and ultrafine particles in the raw material results in difficulty of the separation, the loss of the valuable components and ecological contamination. Secondary using of the fine particles is impossible without their granulation. This problem has been solved by the agglomeration-in-liquid method.An agglomeration-in-liquid method is a process to produce agglomerates in a liquid phase from solid particles suspended in the liquid. The surface of solid particles and the binding liquid must be of identical polarity, but the continuous phase must be of the opposite polarity. The water solutions of the surfactant are the binding liquids or the organic liquids. 相似文献
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《Physics and Chemistry of Liquids》2012,50(5):671-677
Similarity of the extrusion curves of non-wetting liquid in a nanoporous medium with different initial fill volume fractions is observed experimentally. The similarity can be explained by the scaling of the interface energy and the self-similarity of the infinite percolation cluster of fluid-filled pores. Understanding the physical processes leading to the observed phenomena is a foundation for the development of high-performance devices for damping and energy storage on the basis of such heterogeneous systems. 相似文献
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Joaquin Barbera Mercedes Marcos Ana Omenat Jose-Luis Serrano Jesus I. Martinez Pablo J. Alonso 《Liquid crystals》2013,40(2):255-262
The synthesis and liquid crystalline behaviour of the first and second generations of a dendrimeric structure based on poly(propyleneimine)(DAB-dendr(NH2)x) are reported. 4-(4-n-Alkoxybenzoyloxy)salicylaldehydes are used as mesogenic moieties attached at the peripheral amino groups of the dendrimers giving rise to dendromesogens with four and eight mesogenic branches. From these dendromesogens, considered as organic ligands, were prepared six metal-containing dendrimers which incorporate two or four copper atoms in their structures. All the dendrimeric ligands and three of the metal-containing dendrimers exhibit liquid crystalline properties which were studied by optical microscopy, DSC, X-ray diffraction and EPR spectroscopy. 相似文献
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Torrent-Sucarrat M Salvador P Geerlings P Solà M 《Journal of computational chemistry》2007,28(2):574-583
An approximated hardness kernel, which includes the second derivative with respect to the density of the kinetic energy, the electron-electron coulomb repulsion, and the exchange density functionals, has been tested for the calculation of the global hardness. The results obtained for a series of 40 cations and neutral systems and 16 anions represent in most cases an improvement of the results obtained using the HOMO-LUMO gap approach and indicate the viability of this approach to evaluate global hardness. In addition, the relevance of the Fukui function approximation and the role of the three components of the hardness kernel in the evaluation of the global hardness have been analyzed. 相似文献
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David Briers Lieven De Cremer Guy Koeckelberghs Stijn Foerier Thierry Verbiest Celest Samyn 《Macromolecular rapid communications》2007,28(8):942-947
A new chromophore, C1 , based on a similar DπA‐structure as in the FTC ‐chromophore but with a hydroxyalkyl spacer perpendicular to the direction of the dipole moment was synthesized. Both chromophores and the CLD ‐chromophore were used to prepare high Tg nonlinear optical vinyl polymers. The influence of the position of the spacer on the DπA‐system on the NLO response of the resulting polymers was investigated.