Unlocking the Functional Value of European-Originated Chrysanthemum Hybrids: Phytochemical and Bioactivity Assessment

Chrysanthemums are appreciated not only for their ornamental and medicinal attributes but also as edible plants long incorporated into teas, infusions, and culinary traditions. Yet, hybrid cultivars specifically adapted to European growing conditions remain poorly characterized with respect to their medicinal potential. In this study, we investigated the phytochemical composition, antioxidant properties, and enzyme-inhibitory activities of inflorescences of four field-grown Chrysanthemum × morifolium ‘Donna’ × C. rubellum ‘Clara Curtis’ hybrids of European origin (CD 7, DC 19, DC 26, CD 46). Their profiles were compared with those of a Chinese tea cultivar (C. morifolium CHR18) and a commercial herbal product (CH B). Chemical constituents were analyzed using GC–MS and LC–MS, while antioxidant activity was evaluated by FRAP, CUPRAC, DPPH, ABTS, and iron-chelating assays; hyaluronidase (HYAL) and butyrylcholinesterase (BChE) inhibition were also assessed. A total of 61 volatile compounds were identified, with several terpenoids—such as chrysanthenone and verbenone—occurring exclusively in the European hybrids. CHR 18 possessed the highest flavonoid and phenolic acid levels, whereas hybrid CD 46 exhibited the most pronounced overall antioxidant performance. Hyaluronidase inhibition was strongest in DC 26 and CD 46 (60–62%), surpassing both reference samples, while BChE inhibition remained generally low. Overall, the results highlight that C. morifolium × C. rubellum hybrids developed for cultivation in the temperate European climate offer a unique combination of phytochemical richness, robust antioxidant activity, and noteworthy enzyme inhibition. These traits underscore their promise as emerging functional chrysanthemum resources and support future applications in European herbal products, nutraceutical development, and region-specific functional food innovation.