This study investigated the secondary metabolites and antimicrobial properties of three varieties of Hibiscus rosa-sinensis. Methanolic extracts from each variety were obtained using a rotary evaporator to ensure the efficient concentration of bioactive compounds. The antimicrobial activity was tested against Staphylococcus aureus using the disc diffusion method. Sterile disc papers were soaked in the methanolic extracts of the three varieties and placed on nutrient agar plates inoculated with the test organism. The plates were incubated for 24 hours, after which the presence of zones of inhibition was recorded. Results revealed that all three varieties exhibited varying degrees of antimicrobial activity, as indicated by the formation of inhibition zones around the discs. Among them, variety two showed the largest zone of inhibition, suggesting a higher antimicrobial potential compared to varieties one and three. Phytochemical screening further confirmed the presence and absence of specific secondary metabolites in each variety. The superior activity of variety two was attributed to its higher alkaloid content, which is known for its antimicrobial effects. Overall, the findings indicate that Hibiscus rosa-sinensis possesses compounds with inhibitory effects against Staphylococcus aureus, supporting its potential as a natural source of antimicrobial agents. Differences among the three varieties highlight the influence of phytochemical composition on antimicrobial efficacy. Further studies are recommended to isolate and characterize the specific bioactive compounds responsible for the observed activity and to evaluate their potential applications in pharmaceutical formulations.
Lilliy et al. (Sun,) studied this question.