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. Author manuscript; available in PMC: 2022 Mar 1.
Published in final edited form as: Toxicol In Vitro. 2020 Dec 29;71:105073. doi: 10.1016/j.tiv.2020.105073

Table 1.

Pilot Set of Chemicals used in Assay Development and Initial Testing for Inhibition of Iodotyrosine Deiodinase (IYD) Activity in Concentration-Response Mode, with Chemical Source, Reported Purity, Maximum Tested Concentration, Median Percent Inhibition (n=3) Produced at Maximum Concentration, and Absolute IC20 and IC50.

Information from the Literature Chemical Sourceg CASRN Chemicalh Purity, % Max Tested Conc., μM Median % Inhibition at Max Conc. IC20 (μM) IC50 (μM)

Known or suspected inhibitors 3-Nitro-L-tyrosine (MNT) a, b, c AA 621-44-3 99.2 200 100 0.01 0.04
3,5-L-Dibromotyrosine (DBT) a, d,e TCI 300-38-9 96.9 200 93 6.72 15.58
3,5-L-Dinitrotyrosine (DNT) a, d TCI 502481-30-3 99.8 200 82 8.73 26.44
Phloxine B f SA 18472-87-2 NA 200 88 17.27 28.70
Triclosan f SA 3380-34-5 99.8 200 64 68.36 133.27
Bromoxynil f ToxCast 1689-84-5 98.2 200 −5 --i --

Non-inhibitors Bisphenol A e SA 80-05-7 99.9 200 4 -- --
Dibutyl phthalate e SA 84-74-2 99.6 200 −6 -- --
Genistein e RPI 446-72-0 NA 200 −12 -- --
g

Chemicals used for development of the screening assay from stocks on hand at EPA/ORD/CCTE/GLTED, sources: AA = Alfa Aesar, TCI=TCI America, SA = Sigma-Aldrich, RPI=Research Products International, ToxCast = received on previous chemical source plate of ToxCast chemicals;

h

Purity of chemical as reported by the vendor. Not available (NA) for phloxine B or genistein.

i

--The chemical did not produce an inhibition curve, or it was not possible to calculate an IC20 or IC50 because the curve did not reach 20% or 50% inhibition.