Enantiomeric ratio of shikonin derivatives as a possible key for the determination of the origin of lithospermi radix.

An HPLC method was developed to resolve the enantiomers of shikonin derivatives of the Lithospermi Radix. The optimum mobile phase on a Chiracel AD column was 5% isopropanol in n-hexane with flow rate of 1 ml/min. Establishment of this method made possible to determine the ratios of shikonin/acetylshikonin or alkanin/acetylalkanin in the same root. The correlation of the ratios of these substance pairs appeared characteristic for the country where they were originated from. All of the Korean species showed significantly higher ratios of shikonin/acetylshikonin and alkanin/acetylalkanin than the Chinese ones. This method would be useful to determine the origin of Lithospermi Radix.