Chlorogenic acid is a phenolic compound abundant in coffee beans, apples, pears, and other plants. It is formed by esterification of caffeic acid and quinic acid. This compound demonstrates strong antioxidant activity by scavenging free radicals and chelating metals. It has been researched for potential benefits in glucose metabolism, blood pressure regulation, and anti-inflammatory effects. In plants, it contributes to defense against pathogens and UV radiation. Chemically stable under acidic conditions but can degrade under alkaline or high-heat processing. It is a key bioactive in dietary sources with bioavailability influenced by gut microbiota metabolism.