title: Antibacterial activities of the methanol extracts and compounds from Erythrina sigmoidea against Gram-negative multi-drug resistant phenotypes.
abstract: BACKGROUND
  In the present study, the methanol extracts from the leaves, as well as compounds namely sigmoidin I (1), atalantoflavone (2), bidwillon A (3), neocyclomorusin (4), 6α-hydroxyphaseollidin (5) and neobavaisoflavone (6) (from the bark extract) were tested for their activities against a panel of Gram-negative bacteria including multi-drug resistant (MDR) phenotypes.
  
  
  METHODS
  Broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the extracts as well as compounds 1-6.
  
  
  RESULTS
  The MIC results indicated that the crude extracts from the leaves and bark of this plant were able to inhibit the growth of 96.3 % of the 27 tested bacteria. Compounds 2-6 displayed selective activities, their inhibitory effects being obtained on 8.3 %, 41.7 %, 58.3 %, 58.3 % and 66.7 % of tested bacteria respectively for 2, 3, 5, 6 and 4. The lowest MIC value of 8 μg/mL was obtained with 6 against Escherichia coli ATCC8739, Enterobacter cloacae ECCI69, Klebsiella pneumoniae KP55, Providencia stuartii NAE16 and Pseudomonas aeruginosa PA01.
  
  
  CONCLUSIONS
  The present study demonstrates that Erythrina sigmoidea is a potential source of antibacterial drugs to fight against MDR bacteria. Neobavaisoflavone (6) is the main antibacterial consituents of the bark crude extract.
authors.affiliation: Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
authors.forename: Doriane E
authors.initials: DE
authors.lastname: Djeussi
authors.affiliation: Department of Pharmaceutical Sciences, CCS, Universidade Federal de Santa Catarina, Florianópolis, 88040-900, SC, Brazil.
authors.forename: Louis P
authors.initials: LP
authors.lastname: Sandjo
authors.affiliation: Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
authors.forename: Jaurès A K
authors.initials: JA
authors.lastname: Noumedem
authors.affiliation: Department of Chemistry, School of Physical Sciences, University of Nairobi, P. O. Box, 30197-00100, Nairobi, Kenya.
authors.forename: Leonidah K
authors.initials: LK
authors.lastname: Omosa
authors.affiliation: Department of Organic chemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon.
authors.forename: Bonaventure
authors.initials: B
authors.lastname: T Ngadjui
authors.affiliation: Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon. kuetevictor@yahoo.fr.
authors.forename: Victor
authors.initials: V
authors.lastname: Kuete
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D045424:Complex Mixtures / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D004895:Erythrina / Q000737:chemistry; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D007529:Isoflavones / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves
chemical_list: D000900:Anti-Bacterial Agents; D045424:Complex Mixtures; D007529:Isoflavones; D010936:Plant Extracts; C549830:neobavaisoflavone