Quinone reductase that provides resistance to thiol-specific stress caused by electrophilic quinones. Also exhibits azoreductase activity. Catalyzes the reductive cleavage of the azo bond in aromatic azo compounds to the corresponding amines. Requires NADH, but not NADPH, as an electron donor for its activity. The enzyme can also reduce a wide range of sulfonated azo dyes. The substrate preference order is methyl Red > Orange II > Ponceau BS > Ponceau S > Orange G > Amaranth. 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. Homodimer. Belongs to the azoreductase type 1 family.