(5R)-3-{[(3S,5S)-1-{[(4R,5S)-3-{[(3S,5S)-5-[(dimethylamino)carbonyl]pyrrolidin-3-yl]sulfanyl}-5-[(1S,2R)-1-carboxy-2-hydroxypropyl]-4-methyl-4,5-dihydro-1H-pyrrol-2-yl]carbonyl}-5-[(dimethylamino)carbonyl]pyrrolidin-3-yl]sulfanyl}-5-[(1S,2R)-1-carboxy-2-hydroxypropyl]-4-methyl-4,5-dihydro-1H-pyrrole-2-carboxylic acid