Chemical Profiles and Biological Effects of Polyphenols in Eucalyptus Genus: A Comprehensive Review on Their Applications in Human Health and the Food Industry

The genus Eucalyptus is an important member of the family Myrtaceae. Eucalyptus plants contain unique and diverse phytochemicals, contributing to their remarkable ecological and economic values. Although the chemical components of several Eucalyptus food products (e.g., essential oil, honey, and wax) have been studied, research efforts are directed to other less characterized Eucalyptus phytochemicals, particularly polyphenols. Notably, some Eucalyptus polyphenols, such as formyl phloroglucinol meroterpenoids, have unique chemical structures with promising health-promoting effects. Thus, chemical characterization and biological evaluation of Eucalyptus polyphenols are critical to promoting their applications. Herein, this review provides a comprehensive summary of the phytochemical studies of Eucalyptus polyphenols and their biological activities, including antimicrobial, antiviral, anticancer, antioxidant, and anti-inflammatory effects. Eucalyptus polyphenols' structure-activity relationship is analyzed in the context of the development of their biological applications. In addition, the utilization of polyphenols from Eucalyptus plants in food preservation and production is summarized.