. "2-[1-(2-amino-thiazol-4-yl)-1-((2S,3S)-2-methyl-4-oxo-1-sulfo-azetidin-3-ylcarbamoyl)-meth-(Z)-ylideneaminooxy]-2-methyl-propionic acid" . "aztreonam" . . . . . . . . . . . . . . . . . .