The molecule is a thiazolidinemonocarboxylate formed by proton loss from the carboxy group of amoxicilloyl-butylamine. It is a conjugate base of an amoxicilloyl-butylamine.
(2R,4S)-2-[(1R)-1-[[(2R)-2-amino-2-(4-hydroxyphenyl)acetyl]amino]-2-(butylamino)-2-oxoethyl]-5,5-dimethyl-1,3-thiazolidine-4-carboxylate