Table 2. Affinity for the Human H₃R of Photoswitchable Azobenzene-Derived H₃R Ligands.

^aPhotostationary state area percentages after illumination with 360 ± 20 nm at 1 mM in DMSO-d₆ and as determined by LCMS analysis at 254 nm.

^bMeasured by displacement of [³H]-N^α-methylhistamine on HEK293T cell homogenates transiently expressing the H₃R.

^cDefined as pK_i PSS cis – pK_itrans.

^dUnsubstituted phenyl.

^eTrans sample contained 3.9 area % cis compound.