Determination of the Ratio between Optical Isomers, Shikonin and Alkannin by High Performance Liquid Chromatography Analysis

The optical isomers, shikonin and alkannin, can be separated by chiral phase high performance liquid chromatography. The results of analysis have shown that the commercial standards of "shikonin" or "alkannin" as well as the red pigments extracted from the roots of some Boraginaceous plants contain both optical isomers in various proportions.