Phenolic profile and antimicrobial activity of leaf extracts from five Artemisia species (Asteraceae)

Abstract

This study aimed to analyse and evaluate the antimicrobial activity and phenolic compounds in the leaf extracts of five Artemisia species (A. alba, A. annua, A. campestris, A. pontica, and A. vulgaris), of which A. annua is of significant medical importance. Although many Artemisia plants are well known from ethnobotanical and phytochemical studies, the biological activity of Artemisia species against phytopathogenic strains is scarcely investigated. Therefore, the presence of phenolic compounds and the antimicrobial activity of dichloromethane-methanol (1:1) leaf extracts of five Artemisia species against phytopathogenic fungi and bacteria were analysed. The phenolic compounds were determined by liquid chromatography mass spectrometry (LC-MS). In total, 13 phenolic compounds and quinic acid were identified and quantified. Chlorogenic acid was the dominant compound in all the samples, while the second dominant compounds were rutin in the A. alba, A. campestris, and A. pontica extracts, vitexin in A. annua, and esculin in the A. vulgaris extracts. Antifungal activity was tested against 12 micromycetes a using mycelial growth assay and the microdilution method. Antibacterial activity was tested against 18 bacterial strains using the well diffusion and microdilution methods. In each test, the highest activity was shown for the extracts of different Artemisia species. The most sensitive micromycetes were Monillinia laxa, Penicillium citreonigrum, and Botrytis cinerea, while Fusarium graminearum B1 was the most resistant. The analysed extracts showed moderate antibacterial activity only against Xanthomonas campestris pv. campestris compared with all the other tested phytopathogens. The study shows that the leaf extracts of certain Artemisia species contain phenolic compounds and showed moderate antimicrobial activity against some species of fungi and bacteria.

Keywords

• antibacterial activity
• antifungal activity
• flavonoids
• phenolic acids