title: Antimicrobial activities of methanol extract and compounds from stem bark of Vismia rubescens.
abstract: BACKGROUND
  The plant, Vismia rubescens (Guttiferae) is popularly used in Cameroon and in several parts of Africa as febrifugal and for the treatment of various microbial infections (skin diseases, diarrhoea and venereal diseases).
  
  
  OBJECTIVE
  This study was mapped out to evaluate the antimicrobial activities of the methanol extract and compounds from the stem bark of Vismia rubescens.
  
  
  METHODS
  Structures of the compounds obtained after column chromatography of the methanol-soluble fraction were determined by spectroscopy and in comparison with published data. The broth micro-dilution method was used to evaluate the antimicrobial activities against three bacteria species (Salmonella typhi, Staphylococcus aureus and Pseudomonas aeruginosa) and four yeast species (Candida albicans, Candida tropicalis, Candida parapsilosis and Cryptococcus neoformans).
  
  
  RESULTS
  Chemical analysis of the methanol extract from the stem bark of Vismia rubescens yielded five known compounds 1,4,8-trihydroxyxanthone (1), 1,7-dihydroxyxanthone (2), physcion (3), friedelin (4) and friedelanol (5). The crude extract and compounds 1, 2 and 3 exhibited both antibacterial and antifungal activities that varied between the microbial species (MIC=3.12-1000 microg/ml). Compounds 2 and 3 were the most active (MIC=3.12-100 microg/ml) while Staphylococcus aureus and Pseudomonas aeruginosa were sensitive to all the tested compounds. The antimicrobial activity of this plant as well as that of compounds 1 and 2 is being reported here for the first time.
  
  
  CONCLUSIONS
  These results provide promising baseline information for the potential use of this plant as well as some of the isolated compounds in the treatment of skin diseases and diarrhoea.
authors.affiliation: Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67 Dschang, Cameroon.
authors.forename: Jean De Dieu
authors.initials: Jde D
authors.lastname: Tamokou
authors.forename: Michel F
authors.initials: MF
authors.lastname: Tala
authors.forename: Hippolyte K
authors.initials: HK
authors.lastname: Wabo
authors.forename: Jules Roger
authors.initials: JR
authors.lastname: Kuiate
authors.forename: Pierre
authors.initials: P
authors.lastname: Tane
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002163:Cameroon; D002855:Chromatography, Thin Layer; D028084:Clusiaceae / Q000737:chemistry*; D005658:Fungi / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology; D018547:Plant Stems / Q000737:chemistry; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000890:Anti-Infective Agents; D010936:Plant Extracts; D012997:Solvents; D000432:Methanol