. Author manuscript; available in PMC: 2016 Aug 23.

Published in final edited form as: J Med Chem. 2010 Dec 28;54(2):495–509. doi: 10.1021/jm100842v

Table 5.

PDE Isozyme Selectivity of the Most Active Tetrahydro-β-carboline-hydantoins and Piperazinedione Derivatives

compd	PDE5A inhibition IC₅₀ (μM, cGMP)^b and CI at p < 0.05	PDE3B inhibition IC₅₀ (μM, cAMP)^b	PDE3B inhibition IC₅₀ (μM, cGMP)^b and CI at p < 0.05	PDE4B inhibition IC₅₀ (μM, cAMP)^b and CI at p < 0.05	PDE11A inhibition IC (μM, cAMP)^b and CI₅₀ at p < 0.05	PDE11A inhibition IC₅₀, (μM, (cGMP)^b and CI at p < 0.05	selectivity index^a
11	0.010 (0.007–0.013)	>50	>50	34 (24.8–47.1)	2.00 (1.4–2.90)	0.31 (0.25–0.38)	31.0
14	0.007 (0.005–0.011)	>50	>50	3.60 (2.80–4.60)	13.00 (10.9–15.6)	1.50 (1.28–1.80)	208.3
45	0.002 (0.0009–0.006)	>50	>50	>50	0.104 (0.09–0.14)	0.011 (0.008–0.015)	5.50
tadalafil	0.003 (0.0007–0.005)	>50	>50	>50	0.30 (0.23–0.38)	0.05 (0.044–0.055)	16.60

IC₅₀ of PDE11A (cGMP)/IC₅₀ of PDE5A (cGMP).

Calculated from at least 8 concentrations, each with quadruple replicates, p < 0.05.