Bertermann R, Kröger N, Tacke R
Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Anal Bioanal Chem. 2003 Mar;375(5):630-4. doi: 10.1007/s00216-003-1769-5. Epub 2003 Mar 13.
Four different diatom species (Chaetoceros debilis, Chaetoceros didymum, Cylindrotheca fusiformis, Nitzschia angularis) were studied by solid-state (29)Si MAS NMR spectroscopy. To determine the Q(2):Q(3):Q(4) ratios in the biosilica deposits of the diatoms, quantitative (29)Si MAS NMR experiments were performed. This analysis did not reveal any differences regarding the molecular architecture of the silica (i.e. the degree of condensation of the SiOH units (2 identical with SiOH --> identical with Si-O-Si identical with + H(2)O)) from the different diatom species. However, complete cells showed significantly smaller Q(4):Q(3) ratios (1.8-1.9) than extracted cell walls (2.5-2.8), indicating the existence of intracellular pools of less condensed silica.
通过固态（29）Si 核磁共振光谱法研究了四种不同的硅藻物种（柔弱角毛藻、双角角毛藻、梭形筒柱藻、角状菱形藻）。为了确定硅藻生物硅沉积物中的 Q(2):Q(3):Q(4) 比率，进行了定量（29）Si 核磁共振实验。该分析未揭示不同硅藻物种的二氧化硅分子结构（即 SiOH 单元的缩合程度（2 个 SiOH → Si-O-Si + H₂O））存在任何差异。然而，完整细胞的 Q(4):Q(3) 比率（1.8 - 1.9）明显小于提取的细胞壁（2.5 - 2.8），这表明存在缩合程度较低的细胞内二氧化硅池。
