Synonyms: Serine,3-hydroxy-N-[2-hydroxy-1-oxo-2-[tetrahydro-2-hydroxy-6-methyl-5-(2-methylbutyl)-2H-pyran-2-yl]propyl]leucylhexahydro-3-pyridazinecarbonyl-N-hydroxyalanyl-N-methylphenylalanylhexahydro-3-pyridazinecarbonyl-,r-lactone;13H,22H-Dipyridazino[6,1-f:6',1'-o][1,4,7,10,13,16]oxapentaazacyclononadecine,cyclic peptide deriv.; Serine, tetrahydro-a,2-dihydroxy-a,6-dimethyl-5-(2-methylbutyl)-2H-pyran-2-acetyl-3-hydroxyleucylhexahydro-3-pyridazinecarbonyl-N-hydroxyalanyl-N-methylphenylalanylhexahydro-3-pyridazinecarbonyl-,(7®2)-lactone