Quinone reductase that provides resistance to thiol-specific stress caused by electrophilic quinones (PubMed:24915188). Shows a preference for naphthoquinones such as plumbagin (PubMed:24915188). Also exhibits azoreductase activity. Catalyzes the reductive cleavage of the azo bond in aromatic azo compounds to the corresponding amines (PubMed:20417637). Preferred substrates are methyl red, amaranth and p-aminoazobenzene sulfonamide (PAABSA) (PubMed:20417637). 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. Rate of quinone reduction is higher than reduction of azo substrates, suggesting the enzyme is better suited for carrying out quinone rather than azo reduction. Belongs to the azoreductase type 1 family.