论文部分内容阅读
报告从日本续断根部的乙醇提取物中分得二个新的五糖三萜皂甙，应用一维SEMDY和旋转坐标NOE差谱等NMR新技术互相配合的方法对它们的结构进行了研究，确定为：3－O－α－L－吡喃鼠李糖（1→3）－β－D－吡喃葡萄糖（1→3）－α－L－吡喃鼠李糖（→2）－α－L－吡喃阿拉伯糖－常春藤甙元－28－O－β－吡喃葡萄糖酯甙（1），和3－O－［β－D－吡喃葡萄糖（1→4）］[α－L－吡喃鼠李糖（1→3）］－β－D－吡喃葡萄糖（1→3）－α－L－吡喃鼠李糖（1→2）－α－L－吡喃阿拉伯糖－齐墩果酸（2）．结果表明，一维SEMDY和旋转坐标NOE差谱技术互相配合的方法测定寡糖链结构十分有效，高度重叠的糖基1H－NMR信号可按一定规律分离，容易鉴别，糖基之间的连接顺序和连接位置可以准确测定，不需要对化合物进行化学降解或衍生化。
Reported from the roots of the ethanol extract of New Zealand divided two new five sugar triterpenoid saponins, the application of one-dimensional SEMDY and NOEX NMR spin-point difference spectrum and other new technologies to their structure were studied to determine (1 → 3) -β-D-glucopyranose (1 → 3) -α-L-rhamnopyranosyl (→ 2) -α- L-arabinofuranosyl-28-O-β-glucopyranoside (1), and 3-O- [β-D-glucopyranose (1 → 4)] [α-L -pyranyl rhamnose (1 → 3)] - β-D-glucopyranose (1 → 3) -α-L-rhamnopyranose (1 → 2) Oleanolic acid (2). The results show that the synergistic method of one-dimensional SEMDY and rotary NOE differential spectroscopy is very effective for the determination of oligosaccharide chain structure. The highly overlapping glycan 1H-NMR signals can be separated by a certain rule and can be easily identified. The order of connection between glycosyl groups And the location of the attachment can be accurately determined without the need for chemical degradation or derivatisation of the compound.