Acetalin-1 (Ac-RFMWMK-NH2), a hexapeptide, is a μ opioid receptor antagonist with high affinity for μ and κ3 opioid receptor, weak affinity for κ1 receptors and no affinity for κ2 receptors.

Used as pharmaceutical intermediates.

TASP 0277308 is a potent and selective sphingosine 1-phosphate 1 (S1P1) receptor antagonist (IC50 = 7.8 nM). TASP 0277308 inhibits S1P-induced chemotaxis (IC50 = 1.1-1.6 nM), HUVEC cell proliferation (IC50 = 3-3.6 nM) and suppresses angiogenesisin vivo.