从薄层层析到天然产物工业制备层析的理论与实践

基于分离理论的共性，通过薄层层析优化难分离物质对的最佳分离条件并直接放大到植物天然产物的工业制备分离。本文对实际应用中的溶剂组成、溶剂强度、溶剂用量及溶剂再利用等问题作了详细论述。最佳溶剂选择性可通过不同溶剂系统在薄层板上所给难分离物质对的最大Rf比值确定；在正相硅胶层析中，主要极性溶剂决定了物质的洗脱顺序；洗脱剂中极少量强极性溶剂(O．5％)或pH值的改变可显著改善拖尾现象；根据Rf值和容量因子(K)及洗脱体积三者之间的关系，Rf在0．1～0．3为用于柱层析的洗脱溶剂强度的最佳范围。

THEORY AND PRACTICE FROM TLC TO INDUSTRIAL PREPARATIVE CHROMATOGRAPHY(IPC)IN THE SEPARATION OF NATURAL PRODUCT

On the basis of the commonness theory of separation,optimum isolation conditions for components difficult to be separated are established by using thin layer chromatography (TLC),and directly scale up to industrial preparative chromatography (IPC) of plant-derived natural products. Solvent composition,solvent strength,solvent dosage and solvent re-utilization in the practical application are evaluated. The best solvent selectivity for IPC can be obtained by comparing the ratio of R f value of different solvent systems on TLC plate with compounds being isolated. The dominant polar solvent in eluent govern the peak sequence,and a little of more polar solvent or pH change can modify tailing peak. And according to the relationship between R f and capacity factor (K) and eluting volumes,the best range of solvent strength for IPC judged with R f value is confirmed from 0.1 to 0.3.