海鞘提取物2-(4-甲氧基苯基)-2-氧代乙酸甲酯的合成

目的合成从太平洋海鞘Polycarpa aurata中提取的天然产物2-(4-甲氧基苯基)-2-氧代乙酸甲酯。方法采取实验的方法,即以苯甲醚为起始原料,经溴化制成Grignard试剂后,和草酸二甲酯在-40℃至室温反应2 h。结果得到2-(4-甲氧基苯基)-2-氧代乙酸甲酯,产率71.1%,并用IR,MS,1H NMR以及元素分析进行了表征。结论所用实验方法,原料易得,和其他合成方法相比产率较高。     

长纹海鞘(Ascidia longistriara)的化学成分研究

从长纹海鞘（Ａｓｃｉｄｉａｌｏｎｇｉｓｔｒｉａｒａ）的氯仿提取物中分离得到２个化合物，经ＩＲ，ＭＳ和ＮＭＲ等波谱方法鉴定，这２个化合物为胆甾７烯３β醇和神经酰胺十八碳酰基鞘氨醇     

Effects of tri‐n‐butyltin (IV) chloride on neurulation of Ciona intestinalis (Tunicata,Ascidiacea): an ultrastructural study

This paper reports the cytotoxic effects of tri‐n‐butyltin (IV) chloride, TBTCl, on the neurulation process of the ascidian Ciona intestinalis. Exposure of the embryos at early neurula stage in 10^?5 and 10^?7 M TBT (IV) chloride solutions for 1–2 h provoked the irreversible arrest of their development. Morphological and ultrastructural observations suggested that most probably there are two principal causes determining the neurulation process block. The first is due to the TBT effects of inhibiting the polymerization and/or degradation of microfilaments and microtubules, proteins that constitute the cytoskeleton. The lack of orientation and extension of both microtubules and microfilaments of actin prevent the shape changes and mobility of neural plate blastomeres indispensable to the neurulation process. The second cause is certainly determined by the ultrastructural modification which mitochondria undergo. The ultrastructural anomalies showed by these organules are so serious as to impede their proper functionality with consequent inhibition of oxidative phosphorylation and ATP synthesis, remarkable metabolic processes that occur during ascidian neurulation. Copyright © 2005 John Wiley & Sons, Ltd.     

In vitro effects of methylmercury on ascidian (Styela plicata) immunocyte responses

This study shows that high methylmercury concentrations are cytotoxic for Styela plicata hemocytes, whereas sublethal concentrations affect immunocyte responses. Moreover, hemocytes exposed to the xenobiotic present a significantly enhanced phenoloxidase activity as revealed in the hemocyte lysate supernatant compared with the control. Although the cytotoxic activity of S. plicata hemocytes toward rabbit erythrocytes is a PO‐dependent cell‐target reaction due to quinone products, it was significantly decreased by suitable methylmercury concentrations in the medium. The same xenobiotic concentrations decreased the hemocyte phagocytic activity toward yeast. In both the responses cell‐target contacts could be affected by methylmercury, whereas the releasing capacity appeared to be unchanged, as indicated by hemocyte PO‐release in the medium. Finally, changes in hemocyte shape and spreading capacity were shown. On the basis of the present results, Styela plicata hemocyte responses could be an additional immunotoxicology test using a microplate method that reveals cell morphological changes and spreading capacity. Copyright © 2007 John Wiley & Sons, Ltd.     

丹参酮类化合物对海鞘油脂氧化稳定性影响

分别用乙酸乙酯和超临界CO2提取柄海鞘和玻璃海鞘中的油脂,得到了多不饱和脂肪酸含量很高的海鞘油脂,即柄海鞘含有89.84%(超临界CO2提取)和75.78%(乙酸乙酯提取)的多不饱和脂肪酸,玻璃海鞘含有69.77%(超临界CO2提取)和61.11%(乙酸乙酯提取)的多不饱和脂肪酸.对丹参进行系统的化学成分研究,从中分离并鉴定出7个化合物,即丹参酮I、丹参酮IIA、隐丹参酮、二氢丹参酮、丹参酮IIB、紫丹参酮甲素和齐墩果酸.以海鞘油脂为底物,用OSI仪测定了几种丹参酮类化合物的抗氧化活性,结果表明二氢丹参酮和丹参酮I是很好的油脂抗氧化剂,添加量为0.01%时,就可使油脂的氧化稳定性提高3~4倍.     

Prepatellamide A, a new cyclic peptide from the ascidian Lissoclinum patella

A new cyclic peptide, prepatellamide A (1), along with three known cyclic peptides (2)-(4), was isolated from the ascidian Lissodinum patella. The structure of prepatellamide A was determined from one- and two-dimensional H and 13C NMR spectra. The known cyclic peptides were identified as patellamides A (2), B (3) and C (4).     

Prepatellamide A, a new cyclic peptide from the ascidian Lissoclinum patella

A new cyclic peptide, prepatellamide A (1), along with three known cyclic peptides (2)— (4), was isolated from the ascidianLissoclinum patella. The structure of prepatellamide A was determined from one- and two-dimensional¹H and¹³C NMR spectra. The known cyclic peptides were identified as patellamides A (2), B (3) and C (4).     

Distomadines A and B, novel 6-hydroxyquinoline alkaloids from the New Zealand ascidian, Pseudodistoma aureum

Distomadines A and B, novel tetracyclic guanidine-containing 6-hydroxyquinoline alkaloids were isolated from the New Zealand ascidian Pseudodistoma aureum and characterised by interpretation of spectroscopic data and chemical derivatisation. Distomadine A exhibited mild antifungal activity but failed to exhibit any biological activity in a range of antitumour, cytotoxicity, anti-inflammatory, and antimycobacterial tests. The known methyl esters of fatty acids eicosapentaenoic acid (EPA), docosahexaenoic acid and eicosatetraenoic acid were also identified in the extract with EPA methyl ester exhibiting mild cytotoxicity to a non-malignant cell line.     

Lissoclinotoxins E and F, novel cytotoxic alkaloids from a Philippine didemnid ascidian

Bioassay-guided fractionation of the MeOH extract from a Philippine didemnid ascidian resulted in the isolation of two new dimeric alkaloids, lissoclinotoxins E (1) and F (2). The polysulfide structures for compounds 1 and 2 were determined by interpretation of spectroscopic data and chemical degradation. Computational chemistry studies suggested that the N-alkyl chains about the tricyclic systems of lissoclinotoxins E and F had trans and cis orientations, respectively. Alkaloids 1 and 2 displayed IC₅₀ values of 2.3 and 1.5 μg/mL, respectively, towards the PTEN-deficient human breast carcinoma cell line, MDA-MB-468.