in contrast , the preferential delta-agonists leu-enkephalin , met-enkephalin , and d-ala2-d-leu5-enkephalin ( dadle ) as well as the mu-agonists morphine , normorphine , d-ala2-gly-ol5-enkephalin ( dago ) , and beta-casomorphin 1-4 amide ( morphiceptin ) were much less potent .
C0014298
enkephalin
C0525773
dago