A chemical analysis of the Pelargonium species: P. odoratissimum, P. graveolens, and P. zonale identifies secondary metabolites with activity against gram-positive bacteria with multidrug-resistance

PLoS One. 2024 Jul 10;19(7):e0306637. doi: 10.1371/journal.pone.0306637. eCollection 2024.

Abstract

The Pelargonium genus encompasses around 280 species, most of which are used for medicinal purposes. While P. graveolens, P. odoratissimum, and P. zonale are known to exhibit antimicrobial activity, there is an evident absence of studies evaluating all three species to understand their chemical differences and biological effects. Through the analysis of the hydroalcoholic extracts of P. graveolens, P. odoratissimum, and P. zonale, using HPLC-DAD-MS/MS, quercetin and kaempferol derivatives were identified in these three species. Conversely, gallotannins and anthocyanins were uniquely detected in P. zonale. P. graveolens stood out due to the various types of myricetin derivatives that were not detected in P. odoratissimum and P. zonale extracts. Evaluation of their biological activities revealed that P. zonale displayed superior antibacterial and antibiofilm activities in comparison to the other two species. The antibacterial efficacy of P. zonale was observed towards the clinically relevant strains of Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus (MRSA) 333, Enterococcus faecalis ATCC 29212, and the Vancomycin-resistant E. faecalis INSPI 032. Fractionation analysis of P. zonale suggested that the antibacterial activity attributed to this plant is due to the presence of quercetin derivatives and kaempferol and its derivatives, alongside their synergistic interaction with gallotannins and anthocyanins. Lastly, the three Pelargonium species exhibited notable antioxidant activity, which may be attributed to their high content of total phenolic compounds.

MeSH terms

  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Antioxidants / chemistry
  • Antioxidants / pharmacology
  • Biofilms / drug effects
  • Chromatography, High Pressure Liquid
  • Drug Resistance, Multiple, Bacterial* / drug effects
  • Gram-Positive Bacteria / drug effects
  • Kaempferols / chemistry
  • Kaempferols / metabolism
  • Kaempferols / pharmacology
  • Microbial Sensitivity Tests
  • Pelargonium* / chemistry
  • Plant Extracts* / chemistry
  • Plant Extracts* / pharmacology
  • Quercetin / metabolism
  • Quercetin / pharmacology
  • Tandem Mass Spectrometry

Substances

  • Plant Extracts
  • Anti-Bacterial Agents
  • Kaempferols
  • Quercetin
  • Antioxidants
  • kaempferol

Grants and funding

Funding was provided by the Universidad de las Americas under the grant number MED.PFS.22.02. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.