The molecule is a penicillinate anion. It is a conjugate base of a 6-aminopenicillanic acid zwitterion. It is a conjugate acid of a 6-aminopenicillanic acid.
(2S,5R,6R)-6-amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate