Phytochemical Composition of the Alien Invasive Species Amorpha fruticosa at the Northern Edge of Its Secondary Distribution Range—In the Arboretum of the Main Botanical Garden of the Russian Academy of Sciences

The studied introduction population of the alien North American species Amorpha fruticosa L. was formed in the Main Botanical Garden of the Russian Academy of Sciences (Moscow) 80 years ago from seeds of different geographical origin. Currently, this population consists of individuals of the second and third generations, which arose as a result of the spontaneous pollination of parental plants. It is the northernmost site of A. fruticosa growth in the secondary distribution range; in southern regions, it usually behaves like an aggressive invasive species and invades natural plant communities. A. fruticosa is known to contain a number of bioactive compounds with valuable pharmacological properties, and the aim of this study was to evaluate the biochemical composition of leaves and fruits at the northern limit of the species’ growth, since stress conditions promote active accumulation of secondary metabolites. The data on the composition of secondary metabolites, on the mineral composition, phenolic compounds, and flavonoids in the leaves and fruits of A. fruticosa, and on the amount and composition of essential oil in the extract from fruits are presented. High levels of adonitol, which is used as a sweetener in products for diabetic patients, have been reported in the fruits of A. fruticosa. α-Copaene, α-pinene, δ-cadinene, α-muurolene, and β- and α-caryophyllene predominate in the essential oil of the fruit, providing its antimicrobial activity. The phytochemical analysis of A. fruticosa from the secondary distribution range confirms the potential of this species as a valuable resource for the pharmacopoeia industry.