The molecule is a penicillin in which the substituent at position 6 of the penam ring is a (2R)-2-amino-2-(cyclohexa-1,4-dien-1-yl)acetamido group. It is a penicillin and a penicillin allergen. It derives from an ampicillin.
(2S,5R,6R)-6-[[(2R)-2-amino-2-cyclohexa-1,4-dien-1-ylacetyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid