抄録
Vitamin K_1 and its alcohol solution were irradiated with ultraviolet light and their photolytic products were subjected to thin layer chromatography using silica gel and chloroform as solvent. The chromatogram of them were nearly the same as of benzene solution, but the area of spot 5 (Rf 0.21) was much larger than spot 5 of benzene solution. These substances were isolated from the degradation products by chromatographic technique and it was elucidated that these substances were K_1-hydroperoxide, K_1-hydroxide, phthiocol, 5-hydroxy-4-methyl-6,7-benzocoumaran-3-one, phytone and polymer.