(1,2,3,6,7,8-Hexahydroxy-10-oxo-9,10-dihydro-anthracen-9-yl)-acetic acid methyl ester 9-anthraceneacetic acid, 9,10-dihydro-1,2,3,6,7,8-hexahydroxy-10-oxo-, methyl ester InChI=1/C17H14O9/c1-26-10(20)4-5-11-6(2-8(18)14(22)16(11)24)13(21)7-3-9(19)15(23)17(25)12(5)7/h2-3,5,18-19,22-25H,4H2,1H Rubanthrone B methyl (1,2,3,6,7,8-hexahydroxy-10-oxo-9,10-dihydroanthracen-9-yl)acetate