UHPLC-HRMS/MS Based Profiling of Algerian Lichens and Their Antimicrobial Activities

Chem Biodivers. 2018 Apr;15(4):e1800031. doi: 10.1002/cbdv.201800031. Epub 2018 Apr 16.

Abstract

Lichens are complex symbiotic organisms able to produce a vast array of compounds. The Algerian lichen diversity has only prompted little interest even given the 1085 species listed. Herein, the chemodiversity of four Algerian lichens including Cladonia rangiformis, Ramalina farinaceae, R. fastigiata, and Roccella phycopsis was investigated. A dereplication strategy, using ultra high performance liquid chromatography-high resolution-electrospray ionization-mass spectrometry (UHPLC-HRMS/MS), was carried out for a comprehensive characterization of their substances including phenolics, depsides, depsidones, depsones, dibenzofurans, and aliphatic acids. Some known compounds were identified for the first time in some species. Additionally, the lichenic extracts were evaluated for their antifungal and antimicrobial activities on human pathogenic strains (Candida albicans, C. glabrata, Aspergillus fumigatus, Staphylococcus aureus, and Escherichia coli). Cyclohexane extracts were found particularly active against human pathogenic fungi with MIC80 values ranging from 8 to 62.5 μg/mL, without cytotoxicity. This study highlights the therapeutic and prophylactic potential of lichenic extracts as antibacterial and antifungal agents.

Keywords: UHPLC-HRMS; algerian lichens; antibacterial activity; antifungal activity; dereplication.

MeSH terms

  • Algeria
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Antifungal Agents / chemistry
  • Antifungal Agents / isolation & purification
  • Antifungal Agents / pharmacology*
  • Aspergillus fumigatus / drug effects
  • Candida / drug effects
  • Chromatography, High Pressure Liquid
  • Dose-Response Relationship, Drug
  • Escherichia coli / drug effects
  • Lichens / chemistry*
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Plant Extracts / chemistry
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology*
  • Staphylococcus aureus / drug effects
  • Structure-Activity Relationship
  • Tandem Mass Spectrometry

Substances

  • Anti-Bacterial Agents
  • Antifungal Agents
  • Plant Extracts