Action of Nitrofuran Derivatives on the Chloroplast System of Euglena gracilis: Effect of Light

SYNOPSIS. When cultures of Euglena are exposed to nitro‐furantoin in the light, there is extensive bleaching and, at higher concentrations, killing. In the dark the same concentrations have essentially no effect. The enhanced activity in light is a consequence of the rapid photolysis of nitrofurantoin to yield 5‐nitro‐2‐furaldehyde which is, in turn, destroyed by light. Nitrofuraldehyde and several other nitrofuran derivatives bleach at low concentrations in the dark. Of 14 nitrofuran derivatives tested, only 4 Schiff's bases which were readily decomposed to nitrofuraldehyde in light were more active in the light than in the dark.