Narender T, Khaliq T
Medicinal and Process Chemistry Division, Central Drug Research Institute, Lucknow 226 001, U.P., India.
Nat Prod Res. 2008 Jun 15;22(9):763-800. doi: 10.1080/14786410701628812.
The modified limonoids isolated from the Meliaceae are too complex or obtained in too small quantities to determine their structures by chemical and spectroscopic means, including 1H NMR. One method of dealing with such problem is direct crystallographic analysis, without or having a heavy atom, which requires an able crystallographic collaborator. The determination of the structure Utilin is one example. The analysis of the 13C NMR spectral data for different compounds has been very useful for the identification of the various skeletal types of limonoids and also for the determination of the substitution pattern. Owing to the great utilities that these data could help the scientific community, who are working in the area of limonoids, we here describe the application of NMR spectroscopy in the structure elucidation of D and B, D-ring seco-limonoids and a collection of 177 compound's 13C NMR spectral data.
从楝科植物中分离出的改性柠檬苦素过于复杂，或者获取量太少，无法通过化学和光谱手段（包括1H NMR）来确定其结构。解决此类问题的一种方法是直接进行晶体学分析，无论是否含有重原子，这都需要有能力的晶体学合作者。Utilin结构的确定就是一个例子。对不同化合物的13C NMR光谱数据进行分析，对于识别柠檬苦素的各种骨架类型以及确定取代模式非常有用。由于这些数据对从事柠檬苦素领域研究的科学界有很大帮助，我们在此描述NMR光谱在D和B、D环裂环柠檬苦素结构解析中的应用，以及177种化合物的13C NMR光谱数据汇总。
