7-Chloro-L-tryptophan oxidase (, RebO) is an enzyme with systematic name 7-chloro-L-tryptophan:oxygen oxidoreductase. This enzyme catalyses the following chemical reaction
The two substrates of this enzyme are 7-chloro-L-tryptophan and oxygen. Its products are 2-iminio-3-(7-chloroindol-3-yl)propionate and hydrogen peroxide. It contains a noncovalently bound flavin adenine dinucleotide. The rection is a step in the biosynthesis of rebeccamycin in the bacterium Lechevalieria aerocolonigenes.