Table 4.

Physiochemical properties of radiolabeled benzamide-based HDAC ligands.

Compound	MW	Log D	RCY	Target	IC50 for HDACs	In Vivo Properties in Rodents	Reference
[11C]22	375.42	1.8	25%	Class I	HDAC1: 60 nM HDAC2: 153 nM	Brain uptake: <0.10% ID/cm3 after 3 min Metabolism: 80% of radioactivity in the brain was unchanged [11C]22 (rat)	[101,105]
[11C]23	268.30	1.0	10–15%	Class I	HDAC1: 45 nM HDAC2: 31 nM HDAC3: 20 nM	–	[105]
[11C]24	344.45	2.1	40%	Class I	HDAC1: 10 nM HDAC2: 20 nM	–	[105]

MW: molecular weight; RCY: radiochemical yield (decay corrected).