the rank order of potency of the agonists was ( - ) -n6- ( r-phenylisopropyl ) -adenosine ( r-pia ) congruent to 5'-n-ethylcarboxamidoadenosine ( neca ) greater than ( + ) -n6- ( s-phenylisopropyl ) -adenosine ( s-pia ) greater than adenosine .
C0050789
n-ethylcarboxamidoadenosine
C0001443
adenosine