Experimental design to extract natural compounds from Calendula flowers

The genus Calendula grows along the coasts of the Mediterranean Sea, including Calendula officinalis (Linn.), Calendula arvensis (Linn.), and Calendula maritima (Guss). Among these species, only the first one is studied in detail for bioactive molecules, pharmacological properties, and it is therefore considered for commercial product as medicines and cosmetics. In this study, ultrasound-assisted extraction (UAE) of C. maritima flowers has been designed, using a hydro-alcoholic mixture at different time points. The extracts were solvent partitioned and partially purified by chromatographic separation. A bioassay-guided separation was performed, using thin-layer chromatography (TLC), allowing the identification of the main bioactive classes present: phenolics and saponins. These results underline C. maritima as a potential and valuable reservoir of bioactive molecules for human benefit. In addition, they contribute to a sustainable model for the conservation of the biodiversity of this species.