InChI=1S/C18H22O8P2/c1-3-17(13-5-9-15(10-6-13)25-27(19,20)21)18(4-2)14-7-11-16(12-8-14)26-28(22,23)24/h5-12H,3-4H2,1-2H3,(H2,19,20,21)(H2,22,23,24)/b18-17+