Iridoid glycosides are a class of monoterpenoid compounds characterized by a cyclopentane ring and a glycosidic bond. They are widely distributed in the plant kingdom, particularly in the families Scrophulariaceae, Lamiaceae, and Rubiaceae. These compounds play significant roles in plant defense against herbivores and pathogens, and they contribute to the sensory characteristics of various herbs and spices. Iridoid glycosides are known for their potential health benefits, including anti-inflammatory, antioxidant, and antimicrobial properties. They are often studied for their pharmacological effects and are considered important in traditional medicine.