title: Anadenanthera colubrina (Vell.) Brenan produces steroidal substances that are active against Alternaria alternata (Fr.) Keissler and that may bind to oxysterol-binding proteins.
abstract: BACKGROUND
  In previous studies, the extract from Anadenanthera colubrina was active against Alternaria alternata in vitro and reduced the disease caused by this fungus on Murcott tangor fruits to levels that have been obtained using commercial fungicides. Therefore, the goal of the present work was to isolate and identify the active substances in this extract and identify in silico their protein target in the fungus.
  
  
  RESULTS
  The bioguided fractionation of the methanol extract from the fruits of A. colubrina resulted in the isolation of β-sitosterol and β-sitosteryl linoleate, which had minimal inhibitory concentrations (MICs) of 250 and 500 µg mL(-1) , respectively, against A. alternata. Under the same conditions, the MICs for two commercial fungicides were 1250 and 19 µg mL(-1) . In silico studies showed that these steroidal substances bind well to oxysterol-binding proteins from Saccharomyces cerevisiae.
  
  
  CONCLUSIONS
  β-Sitosterol and β-sitosteryl linoleate, produced by A. colubrina, are active against A. alternata. In silico studies suggest that these substances may act by binding to oxysterol-binding proteins. Therefore, both substances and these proteins have potential use in the development of new steroidal structures and analogues to control the disease caused by A. alternata.
authors.affiliation: Departamento de Química, Universidade Federal de Lavras, Lavras, MG, Brasil.
authors.forename: Viviane Ac
authors.initials: VA
authors.lastname: Campos
authors.forename: Fabiano J
authors.initials: FJ
authors.lastname: Perina
authors.forename: Eduardo
authors.initials: E
authors.lastname: Alves
authors.forename: Jaqueline
authors.initials: J
authors.lastname: Sartorelli
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Moura
authors.forename: Denilson F
authors.initials: DF
authors.lastname: Oliveira
mesh_terms: D000528:Alternaria / Q000187:drug effects* / Q000254:growth & development* / Q000648:ultrastructure; D002957:Citrus / Q000382:microbiology; D003198:Computer Simulation; D007887:Fabaceae / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000494:pharmacology*; D010935:Plant Diseases / Q000517:prevention & control*; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D011987:Receptors, Steroid / Q000378:metabolism; D012855:Sitosterols / Q000302:isolation & purification / Q000494:pharmacology*; D000098825:Oxysterol Binding Proteins
chemical_list: D005659:Fungicides, Industrial; D010936:Plant Extracts; D011987:Receptors, Steroid; D012855:Sitosterols; D000098825:Oxysterol Binding Proteins
keywords: Alternaria alternata; Anadenanthera colubrina; docking; fungicide; oxysterol-binding protein; sitosterol