Chemically, it is a derivative of naphthoquinone, related to vitamin K. Plumbagin is a yellow dye, formally derived from naphthoquinone. Lapachol, a yellow, skin-irritating naphthoquinone, is often found in the wood. Diazonaphthoquinone (DNQ) is a diazo derivative of naphthoquinone. The chemical structure as a naphthoquinone derivative was first determined by Brockmann in 1936. "C. edulis" also contains a naphthoquinone, cordeauxione (cordeauxiaquinone). It also contains the naphthoquinone malvone A, which is also a phytoalaxin. Naphthoquinone is a class of organic compounds structurally related to naphthalene. Naphthoquinone functions as a ligand through its electrophilic carbon-carbon double bonds. Naphthoquinone forms the central chemical structure of many natural compounds, most notably the K vitamins.