Synthesis and biological evaluation of Nα-hydroxysulfonyl-[Nle28,31]-CCK26–33

Abstract Two analogues of [Nle 28,31 ]-CCK 26–33 containing an N-terminal acetyl or N-terminal hydroxysulfonyl moiety were prepared and characterized. Both analogues were equipotent to native CCK 26–33 in four bioassays, demonstrating that N-terminal sulfation of CCK 26–33 analogues is compatible with full biological activity.