海洋浮游植物分解和代谢产物中高分子有机物的紫外、红外和~1H-核磁共振光谱特征

用GDX 102树脂从海洋浮游植物三角褐指藻(Phaeodactylum tricornutum)的分解产物和代谢产物中分离提取腐植类物质(DHS,EHS)及乙醇可溶物(DES,EES),用~1H-NMR,IR和UV光谱进行结构分析,并同海水中腐植质(HS)和乙醇可溶物(ES)做了比较。结果表明,DHS,EHS和HS都以高支链烷烃、碳水化合物和氨基酸结构为主要组分,另有少量芳烃和杂环化合物。它们的化学结构很相似,说明DHS和EHS是海水腐植质的重要来源。

~1H-NMR, IR AND UV SPECTROSCOPIC CHARACTER OF HIGH MOLECULAR WEIGHT COMPOUNDS FROM DEGRATION AND EXCRETION PRODUCTS FROM MARINE PHYTOPLANKTON

Marine humic materials have significance in aquatic ecosystem, participating in many biological, chemical and physical processes occured in ocean. There is an extensive relationship between the properties of humic materials and their precursors. The investigation of structral character of the humic precursors leads to the further knowledge of the function of humic material in aquatic ecosystem. The work has firstly isolated humic precursors (DHS, EHS) and ethanol-soluble substances (DES, EES) from degradation and excretion products from the diatom Phaeodactylum tricornutum by GDX-102 resin. The structure of the compounds isolated has been investigated by 1H-NMR, IR and UV spectroscopy, comparison with marine humic materials (HS) and ethanol-soluble substance (ES) being made. The results indicate the similarity of chemical structure of HS, DHS and EHS. Alkyl chains, carbohydrates and amino acid derivatives and to a lesser extent aromatic, heterocyclic materials are important contributors to the structure of HS, DHS and EHS. Many low molecular weight compounds (such as formate, methanol and acetic acid) were released from macromolecular network of humic material after basic hydrolysis, forming many discrete signals in 1H-NMR spectroscopy. The presence of many active groups in EHS and DHS, such as nitriles (probably they are degradation products from proteins, nucleic acids and porphrin), indicates that EHS and DHS are still in the processes of humification. There are structral differences among ES, EES and DES. Alkyl chains (probably from lipids in algae) are present in greater proportion in ES and DES than in EES. There appears to be different types of carbonyl groups occurred in ES, EES and DES (the carbonyl-group absorbance of ,ES, EES and DES in IR spectra are 1 720 cm-1, 1 750 cm-1 and 1 680 cm-1, respectively). Active components are present in EES and DES, indicating their potential instability.