other opioid agonists mimicked this ekc effect and the rank order of potency was dynorphin ( 1-13 ) = greater than ekc greater than levorphanol = morphine = b-endorphin = dihydromorphine greater than leu-enkephalin greater than ( d-ala ) 2- ( d-leu ) 5-enkephalin ( dadl ) = morphiceptin .
C0014294
leu-enkephalin
C0014298
enkephalin