AR-A 2 is a selective 5-HT1B receptor antagonist, with a high affinity to guinea pig cortex 5HT1B 1D and recombinant guinea pig 5-HT1B receptors (Ki: 0.24 and 0.47 nM) and with 10-fold lower affinity to guinea pig 5-HT1D receptor (Ki: 5 nM).
5-HT6 5-HT2AR antagonist-1 is a powerful and effective compound that acts as a dual antagonist for both the 5-HT6 and 5-HT2A receptors. It exhibits high potency with K i values of 11 nM and 39 nM for the respective receptors [1].