Essentials Oils from Brazilian Eugenia and Syzygium Species and Their Biological Activities

TheEugeniaandSyzygiumgenera include approximately 1000 and 1800 species, respectively, and both belong to the Myrtaceae. Their species present economic and medicinal importance and pharmacological properties. Due to their chemical diversity and biological activity, we are reporting the essential oils of 48 species of these two genera, which grow in South America and found mainly in Brazil. Chemically, a total of 127 oil samples have been described and displayed a higher intraspecific and interspecific diversity for bothEugeniaspp. andSyzygiumspp., according to the site of collection or seasonality. The main volatile compounds were sesquiterpene hydrocarbons and oxygenated sesquiterpenes, mainly with caryophyllane and germacrane skeletons and monoterpenes of mostly the pinane type. The oils presented many biological activities, especially antimicrobial (antifungal and antibacterial), anticholinesterase, anticancer (breast, gastric, melanoma, prostate), antiprotozoal (Leishmaniaspp.), antioxidant, acaricidal, antinociceptive and anti-inflammatory. These studies can contribute to the rational and economic exploration ofEugeniaandSyzygiumspecies once they have been identified as potent natural and alternative sources to the production of new herbal medicines.