Synonyms: Cyclo(L-isoleucyl-D-2,3,4,5-tetrahydro-3-pyridazinecarbonyl-L-2,3,4,5-tetrahydro-3-pyridazinecarbonyl-N-methyl-D-phenylalanyl-L-prolyl-D-phenylalanyl);2H,12H-Dipyridazino[1,6-a:1',6'-d]pyrrolo[1,2-j][1,4,7,10,13,16]hexaazacyclooctadecine,cyclic peptide deriv.; L 365209