preferred_name: 1,21-DIMETHYL (3S,6S,7S,15S,16S,19S)-3,19-BIS(1,1-DIMETHYLETHYL)-7,15-DIHYDROXY-4,11,18-TRIOXO-6,16-BIS(PHENYLMETHYL)-9,13-BIS((4-(2-PYRIDINYL)PHENYL)METHYL)-2,5,9,10,12,13,17,20-OCTAAZAHENEICOSANEDIOATE