2-Thiouracil

2-Thiouracil (Thiouracil) is a selective neuronal nitric oxide synthase (nNOS) inhibitor with a K_i value of 20 μM. 2-Thiouracil antagonizes BH4-induced nNOS dimerization. 2-Thiouracil is also an antithyroid compound and a highly specific melanoma detector. 2-Thiouracil stimulates the growth of pea and corn root segments^[1][2][3]. IC50 & Target:Ki: 20 μM (nNOS)^[1] In Vitro:2-Thiouracil (500 μM) significantly reduced the number of nNOS dimers formed in the presence of BH4 (1 μM)^[1].
In the synthetic melanin experiment, 2-Thiouracil (molar ratio to substrate not greater than 0.5) reduced the A₃₅₀ value of the synthetic melanin, and the yield of PTCA and PDCA varied with the pigment precursor, and the melanin yield also varied^[2].
In the DHI oxidative polymerization experiment, 2-Thiouracil (2 mol equivalent) inhibited the conventional oligomerization mode of indole and generated new major products, including 1:1 DHI-TU adduct and its dimers and trimers^[2].
2-Thiouracil (1-5 mM) stimulates root growth in pea and corn roots, and this stimulatory effect varies among treatments and root regions^[3].
In Vivo:2-Thiouracil (2-¹⁴C labeled; 10 μCi; i.v.; single dose) rapidly incorporates tumor pigment and significantly reduces A₃₅₀ and PTCA production in melanoma-bearing mice^[2].