The molecule is tetraanion of methanofuran arising from deprotonation of all five carboxy groups and protonation of the amino group; major species at pH 7.3. It is a conjugate base of a methanofuran.
(3R,4S)-7-[[(1S)-4-[[(1S)-4-[2-[4-[[5-(azaniumylmethyl)furan-3-yl]methoxy]phenyl]ethylamino]-1-carboxylato-4-oxobutyl]amino]-1-carboxylato-4-oxobutyl]amino]-7-oxoheptane-1,3,4-tricarboxylate