tetrabenzyl (6S,11S,16S)-2,2-dimethyl-4,9,14-trioxo-3-oxa-5,10,15-triazaoctadecane-6,11,16,18-tetracarboxylate

(2S)-2-[[(4S)-4-carboxy-4-[[(4S)-4-carboxy-4-[[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methyl-methylamino]benzoyl]amino]butanoyl]amino]butanoyl]amino]butanoyl]amino]pentanedioic acid