(1S,5R,6S)-2-(1-Carbamoylmethyl-3-pyridinio)thiomethyl-6-<(R)-1-hydroxyethyl>-1-methylcarbapen-2-em-3-carboxylate

(1S,5R,6S)-6-<(R)-1-Hydroxyethyl>-1-methyl-2-<1-(2-pyridyl)methyl-3-pyridinio>thiomethylcarbapen-2-em-3-carboxylate

(1S,5R,6S)-6-<(R)-1-Hydroxyethyl>-1-methyl-2-(1-methyl-6-chloro-3-pyridinio)thiomethylcarbapen-2-em-3-carboxylate