Triterpenoid Saponins and Flavonoid Glycosides from the Flower of Camellia flavida and Their Cytotoxic and α-Glycosidase Inhibitory Activities

Camellia flavida var. flavida, commonly known as “Jinhua Tea”, has its flowers and leaves traditionally utilized as tea and functional food sources. However, there is limited knowledge about its bioactive components and their biological activities. This study isolated ten previously unidentified glycoside compounds from the flowers of Camellia flavida, including three oleanane-type triterpenoid saponins (compounds 1–3) and seven flavonoid glycosides (compounds 4–10), collectively named flavidosides A–J. This study assessed the cytotoxicity of these compounds against a panel of human cancer cell lines and their α-glucosidase inhibitory activities. Notably, flavidoside C showed significant cytotoxicity against BEL-7402 and MCF-7 cell lines, with IC50 values of 4.94 ± 0.41 and 1.65 ± 0.39 μM, respectively. Flavidoside H exhibited potent α-glucosidase inhibitory activity, with an IC50 value of 1.17 ± 0.30 mM. These findings underscore the potential of Camellia flavida in the development of functional foods.