Abstract Hibiscus rosa-sinensis L. flower has been known to contain polyphenolic compounds, so the current study focuses on the isolation, identification, characterization, and biological applications of flavonoid compounds from H. rosa-sinensis flower, with an emphasis on antioxidant and antibacterial activities. Flavonoid was extracted from flower extract in ethyl acetate and characterized using chemical tests, TLC, UV, HPLC, FTIR, 1 H-NMR, and 13 C-NMR. Azaleatin-3,7-di-O-glucoside, a quercetin derivative, was found to effectively scavenge DPPH, ABTS, and Nitric oxide (IC 50 = 24.61, 22.38, and 39.79 μg/mL) and antioxidant activity index (AAI) determined to be 1.015, indicating a strong level of antioxidant activity, while PASS prediction revealed the higher antioxidant (Pa = 0.786). Furthermore, Azaleatin-3,7-di-O-glucoside demonstrated greater antibacterial activity against Staphylococcus aureus, a gram-positive bacteria, than against gram-negative bacteria such as Escherichia coli . The study concluded that flavonoid compounds can be used as antibacterial and antioxidant agents, as well as has powerful free-radical scavenging properties, which may be mediated by their phenolic and flavonoid concentrations, and are an excellent source for the medical and pharmaceutical industries and human society.
Kesavan et al. (Thu,) studied this question.