Synthesis of Conformationally Lockedl-Iduronic Acid Derivatives: Direct Evidence for a Critical Role of the Skew-Boat2S0 Conformer in the Activation of Antithrombin by Heparin
作者:Sanjoy K. Das、Jean-Maurice Mallet、Jacques Esnault、Pierre-Alexandre Driguez、Philippe Duchaussoy、Philippe Sizun、Jean-Pascal Herault、Jean-Marc Herbert、Maurice Petitou、Pierre Sinaÿ
DOI:10.1002/1521-3765(20011119)7:22<4821::aid-chem4821>3.0.co;2-n
日期:2001.11.19
of these three fixed conformations. A covalent two atom bridge between carbon atoms two and five of L-iduronic acid was first introduced to lock the pseudorotational itinerary of the pyranoid ring around the 2S0 form. A key compound to achieve this connection was the D-glucose derivative 5 in which the H-5 hydrogen atom has been replaced by a vinyl group, which is a progenitor of the carboxylic acid
我们已经使用有机合成来了解L-艾杜糖酸构象柔韧性在肝素激活抗凝血酶中的作用。在代表肝素抗凝血酶结合位点的真正五糖序列的已知合成类似物中,我们选择了甲基化抗因子Xa五糖1作为参考化合物。与真正的原始片段一样,该分子的单个L-艾杜糖醛酸部分存在于水溶液中作为三个构象异构体1C4、4C1和2S0之间的平衡。因此,我们合成了1的三个类似物,其中L-艾杜糖醛酸单元被锁定在这三个固定构象之一中。首先引入在L-艾杜糖醛酸的两个碳原子和五个碳原子之间的共价两个原子桥,以将吡喃环的假旋转路线锁定在2S0形式周围。实现这种连接的关键化合物是D-葡萄糖衍生物5,其中H-5氢原子已被乙烯基取代,乙烯基是羧酸的祖先。对该分子的选择性操纵产生2S0型五糖23。从D-葡萄糖衍生物28开始,现在在碳原子3和5之间建立了一个共价的两个原子桥,以将L-艾杜糖酸部分锁定在1C4椅子周围形成1C4型五糖43。最后,由于在第5位上