Synonyms: BMY 46572;L-Valine,N-[(6-methoxy-2-quinoxalinyl)carbonyl]-D-seryl-L-trans-4-(acetyloxy)-2,3,4,5-tetrahydro-3-pyridazinecarbonylglycyl-N-methylglycyl-3-hydroxy-N-methyl-,cyclic (5®1'),(5'®1)-dilactone withN-[(6-methoxy-2-quinoxalinyl)carbonyl]-D-seryl-L-trans-2,3,4,5-tetrahydro-4-(2-methyl-1-oxopropoxy)-3-pyridazinecarbonylglycyl-N-methylglycyl-3-hydroxy-N-methyl-L-valine