1H,6H-naphtho[1,8-cd]pyran-1,6-dione, 5-hydroxy-7-phenyl- 5-hydroxy-7-phenyl-1H,6H-benzo[de]isochromene-1,6-dione InChI=1/C18H10O4/c19-14-8-11-9-22-18(21)13-7-6-12(10-4-2-1-3-5-10)16(15(11)13)17(14)20/h1-9,19