Reduction of Menadione in Hexane by Chlorophyll a under Ultra-violet Irradiation

WE have found that chlorophyll can reduce vitamin K upon illumination. This reaction can be followed by the loss of fluorescence induced by exposure of chlorophyll to light in the presence of vitamin K. This loss of fluorescence occurs at concentrations and intensities of illumination at which the fluorescence of chlorophyll alone does not vanish. The reduction of vitamin K to the hydroquinone form can be shown by reduction of 2,6-dichlorophenol-indophenol.