a-Sulfobenzylpenicillin

6α-[(R)-Phenyl(sulfo)acetylamino]penicillanic acid

(2S,5β)-3,3-Dimethyl-7-oxo-6α-[[(R)-phenyl(sulfo)acetyl]amino]-4-thia-1-azabicyclo[3.2.0]heptane-2β-carboxylic acid

(2S,5R,6R)-3,3-dimethyl-7-oxo-6-[(2-phenyl-2-sulfoacetyl)amino]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid