The parent compounds are aromatic and have two double bonds; there are successively reduced analogs (azolines and azolidines) with fewer.
Imidazole and other five-membered aromatic heterocyclic systems with two nitrogens are extremely common in nature and form the core of many biomolecules, such as histidine.
The search for antifungal agents with acceptable toxicity profiles led first to the discovery of ketoconazole, the first azole-based oral treatment of systemic fungal infections, in the early 1980s.
Later, triazoles fluconazole and itraconazole, with a broader spectrum of antifungal activity and improved safety profile were developed.
Such azoles possess a good activity in solvents and water-based formulations, and are effective against wood-destroying, rot fungi.