Abstract
Hydroxyaldoxypropyl (HAP) Sephadex column chromatographic separation of photoisomers from an irradiated mixture of 7-dehydrocholesterol (7-DHC) was investigated and the following satisfactory results were obtained. (1) When the reaction mixtrue of 7-DHC irradiated with the monochromatic light of 295 nm was applied to the HAP Sephadex column chromatography, four separatable peaks were observed on the chromatogram. The data of UV spectra, TLC, GLC and HPLC showed that each peak contained previtamin D_3,vitamin D_3,tachysterol_3 and 7-DHC according to the order of elution from the column, respectively. (2) Since the irradiation with the light of 295 nm produced little amounts of lumisterol_3,the light of 320 nm known to produce comparatively large amounts of lumisterol_3 was chosen for the irradiation. When the irradiated mixture was applied to the column chromatography, lumisterol_3 was not separated from previtamin D_3. However, since previtamin D_3 is easily isomerized to vitamin D_3 by heating, the identification of lumisterol_3 will be possible by applying the thermal isomerized mixture to the column chromatography.
