Showing structure for [(1r,3r)-8-[(1r,3r)-3-(carboxymethyl)-4,6,9-trihydroxy-1-methyl-5,10-dioxo-1h,3h,4h-naphtho[2,3-c]pyran-8-yl]-4,6,9-trihydroxy-1-methyl-5,10-dioxo-1h,3h,4h-naphtho[2,3-c]pyran-3-yl]acetic acid