Polyphenols and terpenes in Mediterranean plants: An overview of their roles and possible applications

The Mediterranean basin represents one of the key hotspots in terms of biodiversity and endemic floristic richness in the world (i.e., a reservoir of plant biodiversity). With ongoing climate change, the Mediterranean vegetation is increasingly exposed to different sources of environmental stresses, such as drought, heat, and solar irradiance. To cope with these severe abiotic stresses, beside morpho-anatomical traits, Mediterranean endemic species enhance the production of secondary metabolites, especially terpenes and polyphenols. These compounds have different roles in plants. Terpene and polyphenol compounds play a key antioxidant function (quenching Reactive Oxygen Species) thus improving ozone and drought tolerance, while also acting as pollinator attractors and repellents for dangerous herbivorous insects (contributing to the taste and odour of different plant tissues). In addition to their roles in plants, these bioactive compounds provide multiple health-promoting benefits for humans. Indeed, they can be used in different types of industries, such as pharmaceutical, nutraceutical, green (as supplements to fossil fuel and insecticides) and cosmetic industries. In conclusion, these compounds may be considered as key innovative components in different technological domains.