title: Erylivingstone A-C with antioxidant and antibacterial activities from Erythrina livingstoniana.
abstract: The chemical study of Erythrina livingstoniana has led to the isolation of three new flavanones namely 5,7,3'-trihydroxy-4'-methoxy-5'-formylflavanone (erylivingstone A) (1), 5,7,3'-trihydroxy-5'-(2-hydroxy-3-methylbut-3-enyl)-4'-methoxyflavanone (erylivingstone B) (2) and 5,7,3'-trihydroxy-5'-(3-hydroxy-3-methyl-trans-but-1-enyl)-4'-methoxyflavanone (erylivingstone C) (3) together with three known compounds (4-6). Their structures were elucidated on the basis of NMR data, HRMS(n) fragmentation pathway and by comparison with literature data. We evaluated the antibacterial efficacies and free-radical scavenging potential of the isolated compounds (1-6). The typical environmental strains of Gram-positive Bacillus subtilis, Gram-negative Escherichia coli, as well as against the clinically important Staphylococcus aureus, Streptococcus pyogenes and E. coli (risk-group 2) were used for the antibacterial assay. Compounds 5 and 6 exhibited the most pronounced efficacy against tested environmental bacteria as well as against the pathogenic strain of E. coli. Compound 3 was also quite active against these three bacterial strains. The isolated compounds showed weak radical scavenging properties with compound 6 being the most active, followed by compounds 2, 3 and 5.
authors.affiliation: Department of Chemistry, University of Botswana, Private Bag 0022, Gaborone, Botswana.
authors.forename: Kibrom Gebreheiwot
authors.initials: KG
authors.lastname: Bedane
authors.affiliation: Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Str.6, 44221 Dortmund, Germany.
authors.forename: Souvik
authors.initials: S
authors.lastname: Kusari
authors.affiliation: Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Str.6, 44221 Dortmund, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Eckelmann
authors.affiliation: Department of Chemistry, University of Botswana, Private Bag 0022, Gaborone, Botswana.
authors.forename: Ishmael B
authors.initials: IB
authors.lastname: Masesane
authors.affiliation: Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Str.6, 44221 Dortmund, Germany. Electronic address: m.spiteller@infu.tu-dortmund.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
authors.affiliation: Department of Chemistry, University of Botswana, Private Bag 0022, Gaborone, Botswana. Electronic address: majindar@mopipi.ub.bw.
authors.forename: Runner R T
authors.initials: RR
authors.lastname: Majinda
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D001412:Bacillus subtilis / Q000187:drug effects; D004895:Erythrina / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects; D044950:Flavanones / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects; D013297:Streptococcus pyogenes / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D044950:Flavanones; C000603147:erylivingstone B; C000603148:erylivingstone C
keywords: Antibacterial; Antioxidant; Erylivingstone A–C; Erythrina livingstoniana; Fabaceae; Flavanone; HRMS(n); NMR