Correlation between antibacterial activity and compound composition of Ardisia mamillata Hance extract

This study investigates the antibacterial potential of extracts from the two different varieties of Ardisia mamillata Hance, a plant known for its medicinal value and natural adaptation to damp, fungal-prone environments. Although widely appreciated for its ornamental and traditional therapeutic uses, its antimicrobial activity remains underexplored. Extracts were prepared from red-leaf (Am_red) and green-leaf (Am_green) variants and tested against two phytopathogenic fungi: Fusarium and Botrytis cinerea. Both variants exhibited antifungal activity, with Am_red extracts showing superior efficacy—achieving a 33.4 % higher average inhibition rate compared to Am_green. In particular, Am_red extracts demonstrated strong inhibition against B. cinerea, with an average inhibition rate of 87.23 %.

UPLC-MS/MS analysis revealed that the dominant chemical classes in both extract types were flavonoids, lipids, amino acids and derivatives, alkaloids, phenolic acids, and organic acids—comprising 86.32 % in Am_red and 85.56 % in Am_green. Several bioactive compounds were identified, including petunidin-3-O-glucoside, calycosin, hispidulin, vanillic acid, and syringic acid. The preliminary data suggests that flavonoids, phenolic acids, and alkaloids are the key contributors to the antibacterial properties observed. The findings highlight the potential of A. mamillata Hance, particularly its red-leaf form, as a source of natural antimicrobial agents for sustainable applications in plant protection and phytopathogen control.