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