1,3,8-trihydroxy-11H-[1]benzofuro[2,3-b]chromen-11-one 11H-benzofuro[2,3-b][1]benzopyran-11-one, 1,3,8-trihydroxy- InChI=1/C15H8O6/c16-6-1-2-8-10(4-6)20-15-12(8)14(19)13-9(18)3-7(17)5-11(13)21-15/h1-5,16-18