Showing structure for 5-{4,10-dihydroxy-7,9-dimethoxy-3-methyl-1h,3h,4h-naphtho[2,3-c]pyran-5-yl}-10-hydroxy-7,9-dimethoxy-3-methyl-1h,3h,4h-naphtho[2,3-c]pyran-4-yl acetate