Uramustine (INN) or uracil mustard is a chemotherapy drug which belongs to the class of alkylating agents. It is used in lymphatic malignancies such as non-Hodgkin's lymphoma. Uracil Mustard selectively inhibits the synthesis of deoxyribonucleic acid (DNA). The guanine and cytosine content correlates with the degree of Uracil Mustard-induced cross-linking. At high concentrations of the drug, cellular RNA and protein synthesis are also suppressed. After activation, it binds preferentially to the guanine and cytosine moieties of DNA, leading to cross-linking of DNA, thus inhibiting DNA synthesis and function. The DNA damage leads to apoptosis of the affected cells. Chemically it is a derivative of nitrogen mustard and uracil.

Thiouracil or 2-thiouracil was introduced in 1943 as the first thionamide anti-thyroid drug. Owing to a high frequency of adverse reactions, especially agranulocytosis, use of thiouracil was abandoned in favor of other, less toxic drugs. Thiouracil is not currently used as a thyrostatic drug in humans. Thiouracil inhibits thyroid activity by blocking the enzyme thyroid peroxidase. It is also it is a highly selective inhibitor of neuronal nitric oxide synthase, by interfering with the substrate- and tetrahydrobiopterin (BH(4))-binding to the enzyme. Due to its ability selectively accumulating in de novo-synthesized melanin in overactive melanin-producing cells and thus providing a means to localize melanoma cells, thiouracil can represent a useful new tool to identify modulators of human hair pigmentation.

Allyl isothiocyanate (AITC), also known as mustard oil, is one of the most common naturally occurring isothiocyanates, which occurs in many common cruciferous vegetables. Besides antimicrobial activity against a wide spectrum of pathogens, it showed anticancer activity in both cultured cancer cells and animal models, although the underlining mechanisms remain largely undefined. Allyl isothiocyanate is a TRPA1 and TRPV1 agonist and pungency and lachrymatory effects of Allyl isothiocyanate are mediated through the TRPA1 and TRPV1 ion channels. Allyl isothiocyanate irritates the mucous membranes and induces eczematous or vesicular skin reactions.

Orotic acid is a minor dietary constituent. Historically it was believed to be part of the vitamin B complex and was called vitamin B13, but it is now known that it is not a vitamin and is synthesized in the body, where it arises as an intermediate in the pathway for the synthesis of pyrimidine nucleotides. Orotic acid is converted to UMP by UMP synthase, a multifunctional protein with both orotate phosphoribosyl transferase and orotidylate decarboxylase activity. The most frequently observed inborn error of pyrimidine nucleotide synthesis is a mutation of the multifunctional protein UMP synthase. As a result, plasma orotic acid accumulates to high concentrations, and increased quantities appear in the urine. Orotic acid levels are elevated in the urea cycle defects ornithine transcarbamylase (OTC) deficiency, citrullinemia and argininosuccinic acidemia, as well as the mitochondrial transport disorder hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome. Orotic acid is also elevated in hereditary orotic aciduria, or uridine monophosphate synthase deficiency, an autosomal recessive disorder characterized by megaloblastic anemia and crystalluria. In addition, orotic acid in combination with leflunomide is in the phase II of clinical trial to evaluate the clinical efficacy and safety of a combination in kidney transplant patients with high levels of Polyoma BK viruria for the purpose of preventing polyoma BK viremia and nephropathy, that could lead to kidney transplant loss from viral damage, acute rejection or both.