title: Antifungal activity of altenusin isolated from the endophytic fungus Alternaria sp. against the pathogenic fungus Paracoccidioides brasiliensis.
abstract: BACKGROUND
  Altenusin is a biphenyl derivative isolated from different species of fungi, which presents several biological activities.
  
  
  OBJECTIVE
  We report the antifungal activity of the altenusin isolated from the endophytic fungus Alternaria sp., against clinical isolates of Paracoccidioides brasiliensis, and its action on cell walls of P. brasiliensis and the nonpathogenic yeast Schizosaccharomyces pombe.
  
  
  METHODS
  In vitro antifungal activity of altenusin was evaluated using the broth microdilution method against 11 strains of P. brasiliensis and one strain of S. pombe. The effects of the altenusin on the cell wall were estimated using the sorbitol protection assay.
  
  
  RESULTS
  The altenusin presented strong activity against P. brasiliensis with MIC values ranging between 1.9 and 31.2 μg/ml, and 62.5 μg/ml for S. pombe. Our results demonstrated that the MIC values for altenusin were increased for P. brasiliensis Pb18 and for S. pombe when the medium was supplemented with sorbitol. Additionally, S. pombe cells treated with altenusin were more rounded in shape than untreated cells.
  
  
  CONCLUSIONS
  Altenusin showed activity against clinical strains of P. brasiliensis at the concentration tested, and this compound probably affects fungal cell walls. These findings suggest that altenusin could act through the inhibition of cell wall synthesis or assembly in P. brasiliensis and S. pombe, and could be considered as a lead compound for the design of new antifungals.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. susjohann@yahoo.com.br
authors.forename: Susana
authors.initials: S
authors.lastname: Johann
authors.forename: Luiz H
authors.initials: LH
authors.lastname: Rosa
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Rosa
authors.forename: Pilar
authors.initials: P
authors.lastname: Perez
authors.forename: Patrícia S
authors.initials: PS
authors.lastname: Cisalpino
authors.forename: Carlos L
authors.initials: CL
authors.lastname: Zani
authors.forename: Betania B
authors.initials: BB
authors.lastname: Cota
mesh_terms: D000528:Alternaria / Q000737:chemistry*; D000935:Antifungal Agents / Q000302:isolation & purification* / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D010228:Paracoccidioides / Q000187:drug effects*
chemical_list: D000935:Antifungal Agents; D001713:Biphenyl Compounds; C095643:altenusin