Phytochemical Constituent of Devil Weed (Chromolaena odorata), Concurrent with Its Antioxidant, α-Glucosidase Inhibitory, and Antibacterial Activity

This study aimed to investigate the phytochemical constituents of <i>C. odorata</i> leaves and stems and to evaluate their antioxidant, total phenol, α-glucosidase, and antibacterial activities. Furthermore, liquid chromatography-high-resolution mass spectrometry (LC-HRMS)-based metabolite profiling combined with principal component analysis (PCA) was applied to correlate metabolite composition with functional activities, providing comprehensive insights into the metabolomic diversity and bioactive differentiation between plant parts. The plant materials were extracted using 70% and 100% ethanol for 24 h. The leaf extract of ethanol 70% (EtOH 70) exhibited the highest antioxidant activity (IC₅₀ of 223.33 ± 9.20 µg/mL) and total phenolic content (113.15 mg GAE/g), while the stem EtOH 70% extract showed the strongest antidiabetic activity through α-glucosidase inhibitory activity (78.57%). Although appearing less potent, all extracts showed dose-dependent inhibitory activity, such as <i>Staphylococcus aureus</i> (highest value at 9.31 mm), <i>Escherichia coli</i> (highest value at 9.92 mm), and <i>Salmonella typhimurium</i> (highest value at 9.00 mm). Comparing the plant parts, leaf extracts generally showed more potent activity than stem extracts, particularly evident against <i>E. coli</i> (e.g., Leaf EtOH 70% at 5 mg/mL: 9.92 mm vs. Stem EtOH 70%: 7.97 mm). LC-HRMS analysis revealed the presence of phenolics, flavonoids, amino acids, organic acids, and alkaloids. Furthermore, the result indicates that <i>C. odorata</i> is a rich source of bioactive compounds with significant antioxidant, α-glucosidase inhibitory, and antibacterial potency. The findings advance existing knowledge beyond earlier phytochemical or single-activity studies, offering a more holistic understanding of <i>C. odorata</i>'s therapeutic potential and its relevance for natural product development.