UPLC-ESI-MS/MS Profiling, Antihaemolysin and Anti-Biofilm Activities of the Underground Parts of Common Iris Specie ^†

Abstract

Microbial resistance inhibition is increasingly focused on the use of plant extracts and their phytochemicals as candidates for targeting virulence factors. Here, we report on the chemical composition and virulence inhibition potential of both polar (PF) and non-polar fractions (NPF) of the underground parts of three common Iris species (I. confusa, I. pseudacorus and I. germanica). The anti-haemolytic and biofilm inhibition potential of the aforementioned Iris species against methicillin-resistant and -sensitive (MRSA and MSSA) S. aureus bacterial strains was explored. I. pseudacorus PF exhibited the most potent effect against S. aureus haemolytic activity. Intriguingly, all the tested fractions from all the species, except I. pseudacorus NPF, had no significant inhibition on the biofilm formation of MRSA and MSSA. Metabolite profiling of the investigated species revealed ninety and forty-five metabolites detected in the PFs and NPFs, respectively. Nigricin-type, tectorigenin-type isoflavonids and xanthones allowed the discrimination of I. pseudacorus PF underground parts from the other species, highlighting the importance of these metabolites in exerting its promising activity. On the other hand, triterpene acids, iridals, triacylglycerols, ceramides, and acid were the metabolites detected in the highest abundance in I. pseudacorus NPF.