An economic point of view of secondary compounds in halophytes

Salt tolerance of halophytes relies on several strategies, among them, the production of species-specific secondary metabolites. Chemically, a broad variety of secondary compounds of economic interest is present in halophytes. Several of these secondary compounds are restricted to halophytic species or are found in higher concentrations than in glycophytes. For their exploitation, optimal plant cultivation conditions and extraction, fractionation and isolation processes need to be identified. On the one hand, the function of single compounds can be more precisely determined and controlled; on the other hand the mixture of compounds in crude extracts might have synergistic effects. Also, different plant organs and plants in different developmental stages contain highly varying amounts and compositions of secondary compounds. Secondary compounds from halophytes have potential uses in various fields such as pharmacognosy, functional foods, nutraceuticals and technical implementations. Many of the potential applications are still in the research and development phase; some products are already on the market. We describe and evaluate the economic potential of several halophytes such as Salicornia spp. and Crithmum maritimum containing valuable compounds used in different applications.