Quinone reductase that provides resistance to thiol-specific stress caused by electrophilic quinones. Can reduce several benzo-, naphtho-, and anthraquinone compounds. Also exhibits azoreductase activity (PubMed:11583992, PubMed:18337254). Catalyzes the reductive cleavage of the azo bond in aromatic azo compounds to the corresponding amines (PubMed:11583992, PubMed:18337254). Can reduce ethyl red, methyl red and p-methyl red, but is not able to convert sulfonated azo dyes (PubMed:11583992, PubMed:18337254, PubMed:23795903). The stoichiometry implies that 2 cycles of the ping-pong mechanism are required for the cleavage of the azo bond (PubMed:11583992). Can also act as a nitroreductase and is able to reduce nitro compounds such as 7-nitrocoumarin-3-carboxylic acid (7NCCA) (PubMed:23795903). 2 a quinone + H(+) + NADH = 2 a 1,4-benzosemiquinone + NAD(+) anthranilate + N,N-dimethyl-1,4-phenylenediamine + 2 NAD(+) = 2-(4-dimethylaminophenyl)diazenylbenzoate + 2 H(+) + 2 NADH Binds 1 FMN per subunit. The azo reduction activity is inhibited by dicoumarol. kcat is 1.1 sec(-1) with anthaquinone-2-sulfonate as substrate. kcat is 2.6 sec(-1) with antraquinone-2,6-disulfonate as substrate. kcat is 5.8 sec(-1) with 2-hydroxy-1,4-naphthoquinone as substrate. kcat is 72.0 sec(-1) with 2-methyl-1,4-benzoquinone as substrate. Homodimer. Expression is induced by electrophiles, including 2-methylhydroquinone, catechol, menadione, and diamide. Deletion mutant displays reduced viability when exposed to electrophilic quinones. NADH cannot be replaced with NADPH for both reductase activities (PubMed:11583992, PubMed:19666717). Quinone compounds are better substrates than the model azo substrate methyl red (PubMed:19666717). AzoR probably does not contribute to dye reduction in vivo (PubMed:19666717). Belongs to the azoreductase type 1 family. Was originally thought to be an ACP phosphodiesterase, but ACP phosphodiesterase activity was not detected in vivo or in vitro in further analysis.