Showing structure for (3r)-8-[(3r)-9,10-dihydroxy-3-methyl-1,6,7-trioxo-3h,4h-naphtho[2,3-c]pyran-8-yl]-9,10-dihydroxy-3-methyl-3h,4h-naphtho[2,3-c]pyran-1,6,7-trione