The molecule is a dicarboxylic acid dianion that is the major structure of isonocardicin A at pH 7.3 (according to Marvin v 6.2.0.). It is a conjugate base of a nocardicin A(1-) and a nocardicin A.
(2R)-2-azaniumyl-4-[4-[(Z)-C-[[(3S)-1-[(R)-carboxylato-(4-hydroxyphenyl)methyl]-2-oxoazetidin-3-yl]carbamoyl]-N-oxidocarbonimidoyl]phenoxy]butanoate