Guaiacol [90-05-1]

Guaiacol is a precursor to various flavorants, such as eugenol and vanillin. Its derivatives are used medicinally as an expectorant, antiseptic, and local anesthetic. It also can be used as an indicator in chemical reactions that produce oxygen. When oxygen binds to it, the complex turns yellowish brown and absorbs light maximally at about 470 nm.(In Vitro):Guaiacol inhibits LPS-stimulated nuclear factor kappa B (NF-κB) activation and cyclooxygenase (COX)-2 gene expression in cells of the RAW 264.7 murine macrophage cell line. Phenolic compounds such as Phenol, Eugenol, Guaiacol and Vanillin inhibit sheep vesicular gland prostaglandin cyclooxygenase, as indicated by their 50% inhibition concentrations, which decline in the following order: Phenol (1600 μM) > Vanillin (>500 μM) > Guaiacol (72 μM) > Eugenol (12 μM).