InChI=1S/C19H17NO7.2Na/c1-3-5-9-16-10(13(21)7-12(18(23)24)20(16)4-2)6-11-14(22)8-15(19(25)26)27-17(9)11;;/h6-8H,3-5H2,1-2H3,(H,23,24)(H,25,26);;/q;2*+1/p-2