EHNA HCl, the hydrochloride salt of EHNA, is a novel and potent inhibitor of adenosine deaminase, also an inhibitor of cGMP-stimulated phosphodiesterase (PDE2) with IC50 of 0.8 – 4 μM.

BAY 73-6691 [(R)-BAY 73-6691] is a novel, potent, selective, and brain penetrant PDE9A (Phosphodiesterase 9) inhibitor.

Nortadalafil (Demethyl Tadalafil) is the demethylated metabolite/impurity of Tadalafil, which is a potent PDE5 inhibitor approved as an oral drug for treating erectile dysfunction (ED).

PF-04447943 (PF04447943) is a novel and potent inhibitor of human recombinant PDE9A with the potential for the treatment of cognitive disorders.

HA130 (HA-130) is a novel, potent and selective inhibitor of autotaxin (ATX, IC50 = 28 nM) with anticancer activity.

BW-A 78U is a novel and potent PDE4 (phosphodiesterase 4) inhibitor with an IC50 of 3 μM.

PF-05180999 is a phosphodiesterase 2A (PDE2A) inhibitor, with an IC50 of 1.6 nM.

CP671305 is a novel, potent, orally bioavailable, and selective inhibitor of phosphodiesterase-4-D with good giological activities.

BRL-50481 is a novel, potent and selective inhibitor of phosphodiesterase 7 (PDE7) with IC50s of 0.15, 12.1, 62 and 490 μM for PDE7A, PDE7B, PDE4 and PDE3, respectively.

Zaprinast is a potent phosphodiesterase (PDE) inhibitor with selectivity for PDE5, PDE6, PDE9 and PDE11 and IC₅₀ values of 0.76, 0.15, 29.0, and 12.0 μM, respectively.