Abstract
An improved procedure for the isolation of suprasterol2 I and II from a photochemical reaction mixture of ergocalciferol (vitamin D2) and their spectral data are described in this paper, when a solution of ergocalciferol in ethanol was irradiated by UV light from a high-pressure mercury lamp, the reaction mixture gave six spots, including suprasterol2 I and II, on the thin-layer chromatogram, while the peaks corresponding to pyro-D2, isopyro-D2, 5, 6-trrans-D2, suprasterol2 I and II were observed in the gas chromatogram obtained from a capillary column GLC (Supra-sterol2 I and II were main peaks). After purifying the mixture by column chromatography on silica gel containing 12% alumina as an adsorbent, two main fractions were isolated. The data of their spectra, TLC and GLC showed that the former fraction was suprasterol2 II while the latter was suprasterol2 I and that the both fractions contained the respective compound only. Both suprasterol2 were crystallized as the 3, 5-dinitro-benzoates.
