Azulene‐Based Systems of Biological Significance

Azulene is a non-alternant hydrocarbon, an isomer of naphthalene with a fused ring system of five and seven members. This aromatic organic compound has a blue color, a unique molecular structure, and biological properties. Some well-known azulene derivatives, such as guaiazulene and chamazulene, are found naturally in various plants and fungi. Azulene and its derivatives are potential candidates in technology, especially in devices that use light and electricity due to their fluorescence properties. They also have medicinal properties and have been used for centuries as ingredients of plants that can treat allergies, infections, and inflammation. This chapter discusses the various biological properties of azulenes and their related derivatives, which include antimicrobial, anti-inflammatory, anti-ulcer, antidiabetic, and antiviral activities, along with the challenges and opportunities in the development of novel derivatives of azulenes of biological importance.