4,6,8-trihydroxy-3a,12a-dihydroanthra[2,3-b]furo[3,2-d]furan-5,10-dione InChI=1/C18H10O7/c19-6-3-8-12(10(20)4-6)16(22)14-9(15(8)21)5-11-13(17(14)23)7-1-2-24-18(7)25-11/h1-5,7,18-20,23 anthra[2,3-b]furo[3,2-d]furan-5,10-dione, 3a,12a-dihydro-4,6,8-trihydroxy-