(5R)-1-{[(1S,6aR)-5-({2-[(azanylidenemethyl)amino]ethyl}sulfanyl)-1-[(1R)-1-hydroxyethyl]-2-oxo-1,2,6,6a-tetrahydroazeto[1,2-a]pyrrol-4-yl]carbonyl}-3-({2-[(azanylidenemethyl)amino]ethyl}sulfanyl)-5-[(1S,2R)-1-carboxy-2-hydroxypropyl]-4,5-dihydro-1H-pyrrole-2-carboxylic acid