Metacresol (m-cresol or 3-methylphenol) is colorless, yellowish liquid. It is used as a bactericide for control of crown gall and olive knot on certain fruit and nut trees and ornamentals and the genetic/physiological disorder burr knot on apples. Currently, one product is registered which contains both m-cresol and xylenol. Used as disinfectant/bacteriocide/germicide for animal pathogenic bacteria (G- and G+ vegetative) in households, sickrooms, hospitals, veterinary clinics, and veterinary hospitals; on surgical instruments, diagnostic instruments/equipment and on hospital critical rubber/plastic items. Used as an insecticide and miticide on dogs for treatment of lice and fleas. It is also used for making synthetic resins; in photographic developers, explosives. Additionally, m-cresol is chemical intermediate for thymol used in cough/cold medicinals, synthetic pyrethroid insecticides, 3-methyl-6-t-butylphenol, trinitro-m-cresol for explosives, and phenolic resins; disinfectant ingredient; ore flotation agent; solvent. m-Cresol, either pure or mixed with p-cresol, is important in the production of contact herbicides. m-Cresol is also a precursor to the pyrethroid insecticides. Furthermore, many flavor and fragrance compounds, such as (-)-methanol and musk ambrette, are derived from m-cresol. Several important antioxidants including synthetic vitamin E are produced from m-cresol. m-cresol is used as a topical dental antiseptic. m-cresol is an effective antimicrobial preservative and is used at low levels (0.3%) in multi-dose peptide and protein formulations. m-cresol has been shown to cause protein aggregation.

Thioguanine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute nonlymphocytic leukemia. Anti-metabolites masquerade as purine or pyrimidine - which become the building blocks of DNA. They prevent these substances becoming incorporated in to DNA during the "S" phase (of the cell cycle), stopping normal development and division. Thioguanine was first synthesized and entered into clinical trial more than 30 years ago. It is a 6-thiopurine analogue of the naturally occurring purine bases hypoxanthine and guanine. Intracellular activation results in incorporation into DNA as a false purine base. An additional cytotoxic effect is related to its incorporation into RNA. Thioguanine is cross-resistant with mercaptopurine. Cytotoxicity is cell cycle phase-specific (S-phase). Thioguanine competes with hypoxanthine and guanine for the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) and is itself converted to 6-thioguanilyic acid (TGMP), which reaches high intracellular concentrations at therapeutic doses. TGMP interferes with the synthesis of guanine nucleotides by its inhibition of purine biosynthesis by pseudofeedback inhibition of glutamine-5-phosphoribosylpyrophosphate amidotransferase, the first enzyme unique to the de novo pathway of purine ribonucleotide synthesis. TGMP also inhibits the conversion of inosinic acid (IMP) to xanthylic acid (XMP) by competition for the enzyme IMP dehydrogenase. Thioguanine nucleotides are incorporated into both the DNA and the RNA by phosphodiester linkages, and some studies have shown that incorporation of such false bases contributes to the cytotoxicity of thioguanine. Its tumor inhibitory properties may be due to one or more of its effects on feedback inhibition of de novo purine synthesis; inhibition of purine nucleotide interconversions; or incorporation into the DNA and RNA. The overall result of its action is a sequential blockade of the utilization and synthesis of the purine nucleotides. Thioguanine is used for remission induction and remission consolidation treatment of acute nonlymphocytic leukemias. It is marketed under the trade name Lanvis and Tabloid among others.