2,3,5,6,8-Pentahydroxy-7-ethyl-1,4-naphthoquinone 2-Ethyl-2,5,6,7,8-pentahydroxy-1,4-naphthoquinone 2-Ethyl-3,6,7-trihydroxynaphthazarin 517-82-8 Echinochrom Echinochrome A