Department of Chemistry, Materials and Chemical Engineering G. Natta, Politecnico di Milano via Mancinelli 7, 20131 Milan, Italy.
Molecules. 2012 Aug 17;17(8):9912-30. doi: 10.3390/molecules17089912.
This manuscript describes the preparation and the spectroscopic characterisation of semi-synthetic sulfated maltotriose C-C linked dimers (SMTCs) where the natural C-O-C anomeric bond was substituted by one direct central C-C bond. This C-C bond induces conformation and flexibility changes with respect to the usual anomeric bond. SMTCs neutral precursors came from maltotriosyl bromide electroreduction through maltotriosyl radical intermediate dimerisation. The new C-C bond configuration, named for convenience α,α, α,β and β,β as the natural anomeric bond, dictated the statistic ratio formation of three diastereoisomers. They were separated by silica gel flash chromatography followed by semi preparative HPLC chromatography. Each diastereoisomer was exhaustively sulfated to afford the corresponding SMTCs. SMTCs were huge characterised by NMR spectroscopy which provided the sulfation degree, too. α,α and α,β were found quite homogeneous samples with a high degree of sulfation (85-95%). β,β appeared a non-homogeneous sample whose average sulfation degree was evaluated at around 78%. Mass spectroscopy experiments confirmed the sulfation degree range. Some considerations were proposed about SMTCs structure-biological properties.
这篇手稿描述了半合成硫酸化麦芽三糖 C-C 连接二聚体 (SMTCs) 的制备和光谱特性，其中天然的 C-O-C 端基键被一个直接的中央 C-C 键取代。与通常的端基键相比，这个 C-C 键诱导了构象和灵活性的变化。SMTCs 的中性前体来自麦芽三溴化物的电化学还原，通过麦芽三糖自由基中间体的二聚化形成。新的 C-C 键构型，为方便起见命名为α,α,α,β和β,β，与天然的端基键相同，决定了三种非对映异构体的统计比率形成。它们通过硅胶快速色谱法分离，然后通过半制备高效液相色谱法进一步分离。每个非对映异构体都被充分硫酸化，得到相应的 SMTCs。SMTCs 通过 NMR 光谱得到了很好的表征，提供了硫酸化程度。α,α 和 α,β 是相当均一的样品，硫酸化程度很高 (85-95%)。β,β 似乎是一个不均匀的样品，其平均硫酸化程度约为 78%。质谱实验证实了硫酸化程度范围。对 SMTCs 的结构-生物学性质提出了一些考虑。
