9-hydroxy-3-(hydroxymethyl)furo[3,2-b]naphtho[2,3-d]furan-5,10-dione InChI=1/C15H8O6/c16-4-6-5-20-15-10-12(19)9-7(2-1-3-8(9)17)11(18)14(10)21-13(6)15/h1-3,5,16-17H,4H furo[3,2-b]naphtho[2,3-d]furan-5,10-dione, 9-hydroxy-3-(hydroxymethyl)-