label: 4-NITROBENZYL (R)-2-DIAZO-4-((2R,3S)-3-((R)-1-HYDROXYETHYL)-4-OXOAZETIDIN-2-YL)-3-OXOPENTANOATE-2-14C
label_lc: 4-nitrobenzyl (r)-2-diazo-4-((2r,3s)-3-((r)-1-hydroxyethyl)-4-oxoazetidin-2-yl)-3-oxopentanoate-2-14c