Photochemical decomposition of alkannin/shikonin enantiomers

Hui Wen Cheng, Fu An Chen, Hsing Chu Hsu, Chau Yang Chen

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Alkannin/shikonin ((±)-5,8-dihydroxy-2-(1-hydroxy-4-methyl-3-pentenyl)-1,4-naphthoquinone), isolated from Macrotomia euchroma, is sensitive to light exposure. A chloroform solution of alkannin/shikonin was exposed to sunlight for 1 month. The major photolytic product, a newly discovered naphthoquinone derivative, was isolated by adsorption chromatography. The chemical structure of the purified photolytic product was identified by NMR, MS and FTIR techniques to be (-)-5,8-dihydroxy-2-(1-hydroxy-3-oxo-4-methyl-4-pentenyl)-1,4-naphthoquinone, indicating that a photo-oxidation reaction had occurred.

Original languageEnglish
Pages (from-to)137-144
Number of pages8
JournalInternational Journal of Pharmaceutics
Issue number2
Publication statusPublished - Jun 30 1995


  • Alkannin/shikonin
  • Macrotomia euchroma
  • Photochemical decomposition
  • Photodegradation

ASJC Scopus subject areas

  • Pharmaceutical Science


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