Phenol itself – simply a benzene ring with an “OH” attached – was first isolated from coal tars, and under its common name carbolic acid sold for wound cleaning and sterilization. This was commonplace in the early 1900s, before the many side effects of phenol overexposure (skin burns, CNS depression, respiratory distress, or coma) were fully realized.
You may already be familiar with many common phenols as components of flavorings and herbal medicines: vanillin, eugenol (clove oil), and guaiacol, a dark note produced from roasting beans or nuts. In fact, thymol, a prominent flavor of the herb thyme, synergizes the activity of the fungicide itraconazole against several common pathogenic fungi. It’s thought that this synergy occurs through disruption of the MAPK signaling pathway in the fungus, or by oxidative stress.