The method of Soxhlet extraction is used to extract gromwell pigment from lithospermum.Three compounds are produced by applying techniques of column chromatography and recrystallization.

• 本文利用索氏提取法从紫草中提取了紫草色素，利用柱层分析和重结晶技术进行了分离纯化，得到了三种化合物。