The genus Calendula belongs to the family Asteraceae. There are about 20 species that are native to the Mediterranean region and have been used by the Greeks, Indians, and Arabs.

Nowadays, Calendula is a plant cultivated all over the world for its ornamental, therapeutic, and health-promoting properties. In Italy, C. officinalis, C. arvensis, and C. maritima are the most widespread species along the coast. C. officinalis is the most used for medicinal, pharmacological, and wellness purposes, possessing a wide range of biological properties: antioxidant, antibacterial, antifungal, and antiviral. All these activities, which are usually extracted from the flowers, are related to the secondary metabolites. These mainly belong to the large classes of polyphenols and terpenes.

In this study, an ultrasound-assisted extraction (UAE) method was carried out on C. maritima flowers, using a hydro-alcoholic mixture (ethanol/water, 60/40 v/v) at various times in the dark. Afterwards, extracts were partitioned with solvents at increasing polarity (petroleum ether, dichloromethane, and butanol). Here, we report the chromatographic separation of butanolic extract, using a Sephadex LH-20 column, whose elution profile was monitored by means of thin-layer chromatography (TLC). The bioassay-guided separation was performed, allowing the identification of the main bioactive classes of compounds: saponins and phenolics. Further investigations for comprehensive chemical and biological activities are needed on C. maritima flowers to identify and characterize the complex system of phytochemicals.

To the best of our knowledge, this is the first time that a chemical and biological screening has been carried out on C. maritima using safe solvents. This is in response to the growing demand for natural products in the context of green and sustainable lifestyles.