Frankincense, also known as olibanum, is the gum oleoresin found on the underside of the bark of Boswellia trees. The main chemical constituents isolated from frankincense are pentacyclic triterpenoids (e.g., β-boswellic acid), tetracyclic triterpenoids (e.g., elemolic acid), macrocyclic diterpenoids (e.g., incensole), and a variety of essential oils from α-pinene to limonene. The resin is thought to possess anti-inflammatory and analgesic properties.