Isolation of Natural Products by Low-Pressure Column Chromatography

This chapter deals with the isolation of natural products using low-pressure liquid column chromatography (LPLC). A brief summary of the adsorption and size-exclusion processes involved in the LPLC is presented. Different types of stationary phases used in both adsorption and size-exclusion LPLC are described along with examples of each type used in LPLC. Operational parameters are also discussed in detail in relation to column packing (both wet and dry), column equilibration, sample application, and column development. An outline of generic procedures for adsorption and size-exclusion LPLC is provided. Sixty-one specific examples of the use of LPLC for the isolation of various natural products, including flavones, coumarins, alkaloids, and triterpenoid saponins from various plants are given. Many of these examples incorporate a combination of adsorption and size-exclusion chromatography to obtain specific compounds.