2,3,6,7,10,11,14,15,18,19,22,23-Dodecaazapentacosanedioic acid,8,20-dimethyl-4,16-bis(1-methylethyl)-12,24-bis(2-methylpropyl)-5,9,13,17,21-pentaoxo-3,7,11,15,19,23-hexakis(phenylmethyl)-,1-(1,1-dimethylethyl) 25-methyl ester, (4S,8S,12S,16S,20S,24S)-