Metabolic profiling of Brachychiton rupestris (T.Mitch. ex Lindl.) K. Schum. leaves using UPLC-ESI-MS and their antimicrobial potential

Abstract

Globally, the number of multi-drug resistant microbes increases critically and the search for novel antimicrobial agents from medicinal plants becomes necessary to overcome such serious problem. The antimicrobial activity of the methanol extract of Brachychiton rupestris leaves and its fractions was assessed against six pathogens through two in-vitro assays: Agar well diffusion and broth microdilution. UPLC-ESI-MS analysis of these samples was also performed. Mucor circinelloides was resistant to the tested samples. The inhibition zone of the samples ranged between 10 and 23 mm while the minimum inhibitory values ranged between 31.25 and 1000 µg/mL. The samples produced significant antimicrobial potential. Based on the UPLC-ESI-MS analysis, the phytochemical profile of both the methanol extract and the ethyl acetate fraction comprise a variety of phenolic compounds and hydroxy fatty acids while that of the n-butanol fraction composed of phenolic compounds mainly flavonoids. B. rupestris could be considered a promising source of natural antimicrobials.