PHYTOCHEMICAL COMPOSITION AND IN VITRO BIOLOGICAL PROPERTIES OF SEVERAL RUDBECKIA HIRTA AND TAGETES ERECTA FLOWER EXTRACTS

The present research focuses on the investigation of the phytochemical profile and biological properties of two ornamental species from the Asteraceae family. Taking into consideration that certain compounds found in such plants can be used as valuable resource for the pharmaceutical and cosmetic industries, we chose to examine the chemical profile in correlation with the biological activities of Rudbeckia hirta and Tagetes erecta flower extracts. Three types of extracts were obtained for each plant product, using solvents with different polarities. Secondary metabolites found in the extracts, such as polyphenols and flavonoids (e.g., caffeic, chlorogenic and gentisic acids, patuletin, quercetin, quercetagetin, quercetagitrin) were quantitatively analysed using HPLC-MS methods. The studied compounds were found to be present in most of the analysed samples in variable quantities, with the highest quantities being found in the ethanolic plant extracts. Positive dose-related values revealed that the investigated extracts exhibit good antioxidant activity through the three investigated mechanisms (ferric reducing capacity, superoxide radical scavenging capacity, hydroxyl radical scavenging capacity). Furthermore, all extracts showed promising antifungal and antibacterial activities, with Tagetes erecta extracts exhibiting better pronounced antibacterial activity, while the most promising antifungal action was observed for Rudbeckia hirta extracts.