title: Antimicrobial structure activity relationship of five anthraquinones of emodine type isolated from Vismia laurentii.
abstract: BACKGROUND
  Antimicrobial activity of anthraquinone compounds of emodine type has been reported by many authors. These compounds are found in Vismia laurentii (Clusiaceae), a plant used in traditional pharmacopoeia for treatment of microbial infections among others affections. The continuous identification of new compounds has raised the problem of the relation between the structure and antimicrobial properties.
  
  
  RESULTS
  The yeast growth kinetics parameters were not influenced by the pH variation as it was the case for the other tested bacteria. Fungicidal activities were noted for all molecules while only few of them had bactericidal activities, mostly on Gram positive bacteria. Mathematical model establishing a quantitative relationship between physicochemical properties of molecules and their fungicidal activities were obtained for Candida albicans and showed that physicochemical properties impacting on antifungal activity were polarizability, partition coefficient, molecular weight and hydrogen bond acceptor.
  
  
  CONCLUSIONS
  This work demonstrated that the presence of a long aliphatic chain methoxy group substituted in position two of the emodine structure increased the antibacterial properties of the studied compounds. Moreover this antimicrobial property depends on the pH of the environment, and specifically on the polarizability and number of hydrogen bond acceptors of the compound.
authors.affiliation: Department of Microbiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
authors.forename: Gislaine Aurelie
authors.initials: GA
authors.lastname: Kemegne
authors.affiliation: Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
authors.forename: Pierre
authors.initials: P
authors.lastname: Mkounga
authors.affiliation: Department of Microbiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
authors.forename: Jean Justin
authors.initials: JJ
authors.lastname: Essia Ngang
authors.affiliation: Department of Microbiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon. sadosylvain@hotmail.com.
authors.forename: Sylvain Leroy
authors.initials: SL
authors.lastname: Sado Kamdem
authors.affiliation: Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
authors.forename: Augustin Ephrem
authors.initials: AE
authors.lastname: Nkengfack
mesh_terms: D000880:Anthraquinones / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D055598:Chemical Phenomena; D028084:Clusiaceae / Q000737:chemistry*; D005658:Fungi / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008826:Microbial Sensitivity Tests / Q000379:methods; D008962:Models, Theoretical; D015394:Molecular Structure; D008970:Molecular Weight; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D015003:Yeasts / Q000187:drug effects / Q000254:growth & development
chemical_list: D000880:Anthraquinones; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D010936:Plant Extracts
keywords: Anthraquinones; Antimicrobial activity; Emodine; Physicochemical property; Structure-activity relationship