Bioactive phytochemicals from Angelica glauca Edgew: a step toward novel therapeutics for respiratory tract...

Due to their vast chemical diversity, natural products derived from medicinal plants, whether as standardized extracts or isolated compounds, hold significant promise for new drug discovery. This study focused on the application of various analytical techniques, including phytochemical screening, extraction, isolation, and characterization of bioactive constituents from Angelica glauca extracts. The antibacterial properties of these isolated compounds were evaluated using the disk diffusion method against respiratory pathogens such as Staphylococcus aureus (MTCC 1144), Streptococcus pneumoniae (MTCC 655), Streptococcus pyogenes (MTCC 442), Pseudomonas aeruginosa (MTCC 2474), and Klebsiella pneumoniae (MTCC 4030). Findings revealed that the methanolic extract of A. glauca contains three primary bioactive compounds: n-hexacosane, stigmasterol, and 6,7-dimethoxycoumarin. Additionally, the extract was rich in alkaloids, flavonoids, glycosides, steroids, saponins, and tannins. Among the isolated compounds, 6,7-dimethoxycoumarin demonstrated the strongest antibacterial activity against S. aureus (17.0 ± 0.97 mm), outperforming n-hexacosane and stigmasterol. These results highlight the therapeutic potential of these compounds in treating respiratory infections and suggest their suitability as candidates for developing new antimicrobial agents. Future research will aim to formulate novel drugs based on these promising bioactive molecules.