Comparative Phytoconstituent Profiling and Antioxidant Activity of Calendula aegyptiaca Hydroalcoholic Stems, Flowers, and Achenes Extracts

Over the last few years, a range of medicinal plants has been studied for their biological features and potential pharmaceutical applications. Phytochemical investigations were conducted on Calendula aegyptiaca stems, flowers, and achenes hydroalcoholic extracts to determine their chemical composition and antioxidant activity. Using liquid chromatography combined with negative electrospray ionization mass spectrometry we managed to identify around 90% of metabolites (78 compounds) with seven phenolic acids and six saponins were tentatively characterized and may represent previously unreported phytochemicals. However, further isolation and spectroscopic characterization are required to confirm their structures. We investigated the antioxidant activity of the extracts using three complementary tests (DPPH radical scavenging test, ferric reducing antioxidant power and total antioxidant capacity). The achenes extract exhibited the highest antioxidant activity across all assays. For DPPH assay, flower and achenes extracts showed radical scavenging activity comparable to vitamin C. In the FRAP assay, flowers and achenes extracts showed higher reducing power than stem extract. The TAC values ranged from 267 mg GAE/g DE to 362 mg GAE/g DE. Phenolic acids, flavonoids, and saponins made up the majority of the extracts. The abundance of phenolic compounds supported the potential antioxidant activity discussed in this study.