Phytochemical profile, antioxidant properties and protein contents of Astragalus tenuifoliosus seeds

Fabaceae seeds are reported to be used for varying medicinal and pharmaceutical purposes. However, knowledge of the nutritive value of Astragalus tenuifoliosus seeds is largely based on very limited data and remains unexplored, we report here the protein content, phenolics as well as the antioxidant potential of plant seeds to give adequate information on its suitability as a new source of natural bioactive compounds. The protein content was determined using the Kjeldahl and Bradford assays. The phytochemical contents were evaluated, and the extracts were further subjected to high-performance liquid chromatography-electrospray ionization - mass spectrometry (HPLC-ESI-MS) analysis. The antioxidant potential was evaluated using the total antioxidant capacity and the free DPPH radical scavenging activity. The results obtained from the protein analysis showed that the total content was 59.43 % of the dry matter basis. The globulins constituted the dominant fraction and followed by albumins, glutelins, and prolamins. The phytochemical investigation showed considerable amounts of polyphenol, flavonoid and condensed tannin amounts. The LC-ESI/MS analysis revealed the presence of 18 phenolics including 8 phenolic acids and 10 flavonoids mostly predominated by quinic acid (255.4 mu g g-1 DW),p-coumaric acid (65.39 mu g g-1 DW), quercetin (97.21 mu g g-1 DW), and cirsiliol (29 mu g g-1 DW). The seeds possessed strong antioxidant potential evidenced by their DPPH radical scavenging activities and total antioxidant capacity. The obtained findings contribute to the limited bibliographic information concerning A. tenuifoliosus seeds and represent a starting point to evaluate its potential as a valuable source of proteins, natural antioxidants, and safe bioactive compounds.

Automated summary

This study investigates the protein content, phenolics, and antioxidant potential of Astragalus tenuifoliosus seeds. The results show that the seeds contain high levels of protein and phenolic compounds, and exhibit strong antioxidant activity.