Isolation and Characterization of Antimicrobial Agents From Ipomoea carnea via Bioactivity-Guided Fractionation,...

Ipomoea carnea, "Bush Morning Glory," belongs to the family Convolvulaceae and is cultivated in Egypt as an ornamental plant. Traditionally, its juice is used topically as an antiseptic for skin lesions. This study aims to identify the most effective solvent fraction for extracting antimicrobial compounds from I. carnea. Leaf and stem extracts were fractionated and tested for activity against Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. Ultrahigh-performance liquid chromatograms (UHPLC)-HRMS analysis was conducted to profile metabolites of dichloromethane (DCM) extract of I. carnea stem. Isolated compounds from the same fraction were subsequently subjected to molecular docking with bacterial dihydrofolate reductase (DHFR) enzyme, and minimum inhibitory concentrations (MICs) were determined. DCM fraction of stem and butanol fractions of both leaf and stem demonstrated broad-spectrum antimicrobial activity. UHPLC-HRMS identified 21 metabolites, including coumarins, lactones, phenolic acid derivatives, and resin glycosides in stem DCM fraction. Three compounds-ethyl caffeate, scopoletin, and umbelliferone-were isolated. These compounds demonstrated significant binding to bacterial DHFR in molecular docking and showed confirmed antimicrobial activity via MIC testing. These encouraging results suggest that I. carnea has potential as a source of antimicrobial agents. However, further research is necessary to confirm its therapeutic applications against infectious diseases.