Table 4.
The top 25 ranked chemicals for inhibition of deiodinase type 2 (DIO2), based on absolute IC50, with activity across the deiodinases (DIOs) indicating which chemicals produced 50% inhibition or greater in each of the deiodinase assays in single-point testing.
| DIO2 |
Across DIOs |
||||||
|---|---|---|---|---|---|---|---|
| Rank | Chemical | CASRN | Max Tested Conc., μM |
% Inhibition at Max Conc.a |
IC20 (μM) |
IC50 (μM) |
≥ 50% Inhibition |
| 1 | Fluazinam | 79622-59-6 | 180 | 100 | 0.5 | 2.2 | DIO 1, 2, 3 |
| 2 | Triflumizole | 68694-11-1 | 200 | 98 | 0.7 | 2.9 | DIO 1, 2, 3 |
| 3 | Bisphenol A diglycidyl ether | 1675-54-3 | 200 | 101 | 1.2 | 3.7 | DIO 1, 2, 3 |
| 4 | Octhilinone | 26530-20-1 | 200 | 79 | 3.4 | 12.2 | DIO 1, 2, 3 |
| 5 | Zoxamide | 156052-68-5 | 200 | 95 | 3.1 | 12.9 | DIO 1, 2, 3 |
| 6 | Chlorhexidine diacetate | 56-95-1 | 200 | 99 | 5.7 | 13.1 | DIO 1, 2, 3 |
| 7 | SSR69071 | 344930-95-6 | 50 | 77 | 4.5 | 13.8 | DIO 2, 3 |
| 8 | 4,5-Dichloro-3H-1,2-dithiol-3-one | 1192-52-5 | 200 | 92 | 3.0 | 15.6 | DIO 1, 2, 3 |
| 9 | 4,5-Dichloro-2-octyl-3(2H)-isothiazolone | 64359-81-5 | 200 | 95 | 2.4 | 16.9 | DIO 1, 2, 3 |
| 10 | Tributyltetradecylphosphonium chloride | 81741-28-8 | 200 | 97 | 9.0 | 17.8 | DIO 1, 2, 3 |
| 11 | Dinocap | 39300-45-3 | 200 | 93 | 3.2 | 18.2 | DIO 1, 2, 3 |
| 12 | (Dicyclopentadienyloxy)ethyl methacrylate | 68169-03-9 | 200 | 83 | 4.4 | 18.4 | DIO 2, 3 |
| 13 | Isooctyl acrylate | 29590-42-9 | 200 | 96 | 4.6 | 18.7 | DIO 1, 2, 3 |
| 14 | Quinoxyfen | 124495-18-7 | 200 | 63 | 4.9 | 18.7 | DIO 2, 3 |
| 15 | Hydramethylnon | 67485-29-4 | 200 | 86 | 16.3 | 19.8 | DIO 2 |
| 16 | Hexadecyltrimethylammonium bromide | 57-09-0 | 200 | 101 | 16.6 | 19.9 | DIO 1, 2, 3 |
| 17 | 2-Ethylhexyl acrylate | 103-11-7 | 200 | 88 | 3.0 | 20.1 | DIO 1, 2, 3 |
| 18 | Methyltrioctylammonium chloride | 5137-55-3 | 200 | 99 | 12.4 | 20.8 | DIO 1, 2, 3 |
| 19 | 6-Hydroxy-2-naphthyl disulfide | 6088-51-3 | 200 | 85 | 2.7 | 21.1 | DIO 1, 2, 3 |
| 20 | Benzalkonium chloride | 8001-54-5 | 200 | 100 | 16.7 | 22.5 | DIO 1, 2, 3 |
| 21 | Dichlone | 117-80-6 | 200 | 94 | 4.0 | 22.6 | DIO 1, 2, 3 |
| 22 | AVE5638 | 725228-45-5 | 200 | 96 | 5.0 | 22.8 | DIO 1, 2, 3 |
| 23 | Hexachlorocyclopentadiene | 77-47-4 | 200 | 87 | 6.0 | 25.5 | DIO 1, 2, 3 |
| 24 | Calcium dodecylbenzene sulfonate | 26264-06-2 | 200 | 94 | 16.5 | 25.6 | DIO 1, 2, 3 |
| 25 | Ascorbyl palmitate | 137-66-6 | 200 | 97 | 6.9 | 26.4 | DIO 1, 2, 3 |
a
Median of three replicates at maximum concentration of chemical in concentration-response testing; inhibition in single-point results differed by 12% or less, except for dinocap, which produced 49.4% inhibition.