. "3-[14,17-Dibenzyl-2-isobutyl-5-(2-methylsulfanyl-ethyl)-3,6,9,12,15,18,23-heptaoxo-1,4,7,10,13,16,19-heptaaza-bicyclo[18.2.1]tricos-21-en-11-yl]-propionamide" . "XI" . . . .