Mineral and Phytochemical Profiles and Antioxidant Activity of Herbal Material from Two TemperateAstragalusSpecies

Abstract

Only a few species of the largeAstragalusgenus, widely used for medicinal purposes, have been thoroughly studied for phytochemical composition. The aim of our research was to investigate the rarely studied speciesA. glycyphyllosL. andA. cicerL. for the distribution of mineral elements and phytochemicals in whole plants at two growth stages and in morphological fractions. We also investigated the capacity of the plant extracts to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and to chelate ferrous ions. Chemical composition and antioxidant properties depended on species, maturity, and plant part. Herbal material ofA. glycyphylloswas richer in Fe, total phenolics, and flavonoids, whereas extracts ofA. cicershowed a higher antioxidant activity. Young plants had more isoflavones, showed greater quenching of DPPH radicals, and exhibited better mineral profiles than flowering plants. Among plant parts, leaves were the most valuable plant material according to most characteristics investigated. Isoflavone concentration in flowers was lower than in leaves and stems. None of theAstragalussamples contained detectable amounts of the alkaloid swainsonine. The study demonstrates the potential of plant material from twoAstragalusspecies as a valuable source of iron, phenolic substances including isoflavones, free-radical scavengers, and Fe2+chelators for pharmaceutical use.