Catalyzes the NADPH-dependent reduction of quinones (PubMed:19349281). Exhibits a low enzymatic activity with beta-naphthoquinones, with a strong preference for the ortho-quinone isomer (1,2-beta-naphthoquinone) over the para isomer (1,4-beta-naphthoquinone). Also displays a low reductase activity for non-quinone compounds such as diamine and 2,6-dichloroindophenol (in vitro) (PubMed:19349281). Involved in the generation of reactive oxygen species (ROS) (PubMed:19349281).
