6H-benzofuro[3,2-c][1]benzopyran-6-one, 8,9-dihydroxy- 8,9-dihydroxy-6H-[1]benzofuro[3,2-c]chromen-6-one InChI=1/C15H8O5/c16-9-5-8-12(6-10(9)17)19-14-7-3-1-2-4-11(7)20-15(18)13(8)14/h1-6,16-17