title: [Isolation and structure identification of the main photolysis product in vitamin K1].
abstract: OBJECTIVE
  To isolate and identify an unknown photolysis product in Vitamin K1.
  
  
  METHODS
  A column chromatography method was used to prepare the impurity, and spectrometric analyses of ultraviolet spectrum, infrared spectrum, mass spectrum and nuclear magnetic resonance spectrum were carried out to identify its structure.
  
  
  RESULTS
  Its structure is 2-methyl-3-(3-hydroxy-3, 7, 11, 15-tetramethyl-1-hexadecenyl)-1, 4-naphthoquinone.
  
  
  CONCLUSIONS
  The structure of the photolysis product has been identified.
authors.affiliation: Department of Pharmaceutical Analysis, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zheng
authors.forename: Ruo-Bing
authors.initials: RB
authors.lastname: Chao
mesh_terms: D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry* / Q000302:isolation & purification; D010782:Photolysis; D013056:Spectrophotometry, Ultraviolet; D010837:Vitamin K 1 / Q000032:analysis / Q000737:chemistry*
chemical_list: C513395:2-methyl-3-(3-hydroxy-3,7,11,15-tetramethyl-1-hexadecenyl)-1,4-naphthoquinone; D009285:Naphthoquinones; D010837:Vitamin K 1