Monoterpenes and Sesquiterpenes of Essential Oils from Psidium Species and Their Biological Properties

<i>Psidium</i> (Myrtaceae) comprises approximately 266 species, distributed in tropical and subtropical regions of the world. <i>Psidium</i> taxa have great ecological, economic, and medicinal relevance due to their essential oils' chemical diversity and biological potential. This review reports 18 <i>Psidium</i> species growing around the world and the chemical and biological properties of their essential oils. Chemically, 110 oil records are reported with significant variability of volatile constituents, according to their seasonality and collection sites. Monoterpenes and sesquiterpenes with acyclic (C₁₀ and C₁₅), <i>p</i>-menthane, pinane, bisabolane, germacrane, caryophyllane, cadinane, and aromadendrane skeleton-types, were the primary constituents. The essential oils showed various biological activities, including antioxidant, antifungal, antibacterial, phytotoxic, larvicidal, anti-inflammatory, and cytotoxic properties. This review contributes to the <i>Psidium</i> species rational and economic exploration as natural sources to produce new drugs.