Naturally occurring and synthetic imidazoles: Their chemistry and their biological activities

Imidazoles are an important class of heterocycles and include many substances of both biological and chemical interest. They are part of a large number of highly significant biomolecules such as the essential amino acid histidine and related compounds, biotin, and the imidazole alkaloids. Insertion of the imidazole nucleus is an important synthetic strategy in drug discovery. Imidazole drugs have broad applications in many areas of clinical medicine. The imidazoles are a class of antifungal azole derivatives and have a broad spectrum of activities both in vitro and in vivo. The imidazole moiety is also contained in many histaminergic ligands for histamine H-1, H-2, and H-3 receptors. These are currently used as tools in pharmacological studies. The important therapeutic properties of imidazole related drugs have encouraged the medicinal chemists to synthesize and test a large number of novel molecules. Some of these have chemotherapeutic properties, such as for example several FTase inhibitors with an imidazole moiety. Imidazole derivatives have also been shown to have antibacterial activity and recently several P38 MAP Kinase inhibitors and 5-Lipoxygenase inhibitors containing the imidazole moiety have been synthesized. This review reports current progress in the area of new biologically active imidazoles and recently discovered naturally occurring imidazole.