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. Author manuscript; available in PMC: 2021 Jan 1.
Published in final edited form as: Med Res Rev. 2019 Jun 13;40(1):158–189. doi: 10.1002/med.21599

Table 1.

Summary of NOS inhibition for relevant compounds


Inhibition (μM)
Compound

iNOS eNOS nNOS Reference Notes

1 1.4 (human, Ki) 0.06 (human, Ki) 0.09 (human, Ki) 123 For the acid form, L-NAME is only a weak inhibitor
2 2.6 (human, Ki) 0.7 (human, Ki) 1.7 (human, Ki) 123 Values for competitive inhibition
3 2.2 (murine, IC50)
3.9 (murine, Ki)
3.9 (bovine, Ki) 3.9 (rat, IC50)
1.7 (rat, Ki)
123, 128 Values for competitive inhibition; also a mechanism-based inactivator
4 54±58 (murine, IC50) Not reported; in vivo results suggest selectivity 160 (rat, IC50) 131,132 Little selectivity later reported
5 3.3 (murine, IC50)
0.9 (human, Ki)
16 (human, Ki) 92 (rat, IC50)
10 (human, Ki)
128, 123 Values for competitive inhibition
6 >1850 (human, IC50) 2420 (human, IC50) >1850 (human, IC50) 138 Is a prodrug; hydrolyzes to 5, little inhibitory activity
7 2.19±0.23 (human, IC50)
<40 nM (human, Kd)
554±61 (human, IC50) 177±44 (human, IC50) 7 Time and NADPH-dependent competitive inhibitors
8 9.03±0.85 (human, IC50)
<90 nM (human, Kd)
>1000 (human, IC50) 719±179 (human, IC50) 7 Time and NADPH-dependent competitive inhibitors
9 2.9 (human, IC50) Exact value not reported; around 25-fold weaker Exact value not reported; around 5-fold weaker 144 Time-dependent, irreversible inhibitor
10 100 (species not specified, IC50) Exact value not reported; in vivo assays suggest no eNOS inhibition Exact value not reported; selectivity is reported to be 8-fold 149
11 130 (species not specified, IC50) Exact value not reported; in vivo assays suggest no eNOS inhibition 180 (species not specified, IC50) 148 Molecular modeling suggests competitive inhibition.
12 0.047 (human, Ki) 9.0 (human, Ki) 0.25 (human, Ki) 150 Proposed to be a competitive inhibitor
13 0.007 (human, Kd) 50 (human, Ki) 2.0 (human, Ki) 151 Originally proposed to be irreversible or a very slow reversible inhibitor
14 0.20±0.03 (presumably human, IC50) 350±70 (presumably human, IC50) Not reported 154 Competitive inhibitor
15 1.0 (human, IC50) 4.7 (human, IC50) 1.1 (human, IC50) 155 Competitive inhibitor
16 0.0019 (human, Ki) 0.018 (human, Ki) 0.0037 (human, Ki) 156, 157 Competitive inhibitor like 15.
17 0.25 (human, IC50) 226 (human, IC50) 3.2 (human, IC50) 160
18 0.78 (human, IC50) 1980 (human, IC50) 27 (human, IC50) 161
19 0.16 (human, IC50)
No significant effect at 100 μM (human)
16 (rat, IC50) 162
20 0.037 (human, IC50) >100 (human, IC50) 1 (human, IC50) 163 Competitive inhibitors.
21 0.4 (human, IC50) 50 (human, IC50) 1 (human, IC50) 166 X-ray crystallography indicates competitive inhibitors.
22 0.17 (human, IC50) 0.072 (human, IC50) 0.074 (human, IC50) 167
23 0.028 (human, IC50) 0.15 (human, IC50) 0.10 (human, IC50) 167
24 0.071 (human, IC50) >100 (human, IC50) 6.6 (human, IC50) 169
25 0.086 (human, IC50) 162 (human, IC50) 17 (human, IC50) 170, 171 Competitive, time-dependent, irreversible inhibitor.
26 7.3±1 (possibly murine, spectral binding constant for iNOS monomer) Not reported Not reported 174 Dimerization inhibitor
27 0.028 (human, IC50, cell lysate)
0.0022 (human, Ki, purified iNOS monomer)
32 (human, IC50, cell lysate) 0.140 (human, IC50, cell lysate) 175 Dimerization inhibitor
28 0.00029 (human, IC50, A172 cell lysate) Selectivity reported to be >5000-fold (vaccinia-transfected cell lysate Selectivity reported to be 62-fold (vaccinia-transfected cell lysate 178 Different selectivity values depending on whether vaccinia transfection or tetracycline induction is used
29 1.3 (human, EC50, cell-based)
46 (murine, EC50, cell-based)
>100 (human, EC50, cell-based) >10 (human, EC50, cell-based) 179 Dimerization inhibitor
30 0.011 (human, EC50, cell-based)
0.12 (murine, EC50, cell-based)
26 (human, EC50, cell-based) 2.3 (human, EC50, cell-based) 179 Dimerization inhibitor
31 0.009 (human, EC50, cell-based)
0.034 (murine, EC50, cell-based)
6.1 (human, EC50, cell-based) 0.36 (human, EC50, cell-based) 179 Dimerization inhibitor
32 0.091 (human, EC50, cell-based) 16.5 (human, EC50, cell-based) 0.30 (human, EC50, cell-based) 181 Dimerization inhibitor
33 ~0.003 (species not specified, IC50) >30 (species not specified, IC50) ~2.4 (species not specified, IC50) 182 Dimerization inhibitor
34 Not reported, but lowers iNOS expression in PC12 cell cultures Not reported Not reported 56 Exact mechanism of action unknown; possibly multiple targets
35 Inhibits NO production in LPS-stimulated macrophages at 20 μM Not reported Not reported 200 Exact mechanism of action unknown; proposed to be a competitive inhibitor