A review of meroterpenoids and of their bioactivity from guava (Psidium guajava L.)

Psidium guajava Linn. (family Myrtaceae), is commonly known as guava. Guava is consumed in large quantities throughout the world due to its ease of cultivation and high nutritional value. As an important perennial fruit tree distributed around the world, guava has been widely used to manage various diseases in traditional medicine. Guava has been shown significant bioactivity such as antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, antidiabetic, and anticancer properties. A large number of studies indicated that guava contains various type of phytochemicals including monoterpenes, sesquiterpenes, triterpenes, phenolics, and meroterpenoids. Among them, meroterpenoids are characteristic components of guava, which are hybrid of acylphloroglucinol with terpenoids (monoterpenes, sesquiterpenes). Modern pharmacological investigations showed intricate Psidium meroterpenoids possess a wide range of bioactivities. Although a large and growing body of literatures have investigated the Psidium meroterpenoids isolated from guava, a comprehensive review of Psidium meroterpenoids and their bioactivities has not been conducted. Therefore, this review provides a comprehensive compile of 75 meroterpenoids isolated from guava and their bioactivities between 2007 and May 2022. Furthermore, the possible biosynthesis way and future directions of Psidium meroterpenoids have also been discussed.