Chemical characterization and antibacterial activity of Mallotus nanus Airy Shaw (Euphorbiaceae)

Abstract

This study characterizes the phytochemical profile and antibacterial activity of ethanolic leaf, stem, and root extracts of Mallotus nanus (M. nanus), a traditional medicinal plant endemic to Vietnam’s Central Highlands. Leaf extract showed the highest total phenolic content (239.00 ± 0.94 mg GAE/g) and total flavonoid content (72.01 ± 0.13 mg QE/g), followed by stem and root extracts. UHPLC analysis identified eleven bioactive constituents (eight flavonoids and three phenolic acids) with organspecific distribution, with leaves enriched in phenolic acids and stems, and roots richer in flavonoids. All extracts inhibited Staphylococcus aureus and Escherichia coli in a concentration dependent manner, with leaf extract producing the largest inhibition zones at 100 mg/mL (21.00 ± 0.00 mm and 22.25 ± 0.35 mm, respectively). Leaf extract also exhibited the strongest MIC/MBC values (6.25/25.00 mg/mL for both strains), exceeding the activities reported previously for other Mallotus species. These findings provide the first UHPLC based profiling of M. nanus and support its leaves as a promising source of phenolic and flavonoidrich extracts for development of plantderived antibacterial agents.