Antibacterial xanthones from Kielmeyera variabilis mart. (Clusiaceae).
The bioassay-guided fractionation of stems from Kielmeyera variabilis, traditionally used in Brazilian folk medicine, yielded assiguxanthone-B (1), kielcorin (4), 2,5-dihydroxybenzoic acid (3), and a mixture of xanthones containing assiguxanthone-B (1) and 1,3,5,6-tetrahydroxy-2-prenylxanthone (2) (1:1 w/w). The xanthone mixture inhibited Staphylococcus aureus and Bacillus subtilis at a concentration of 6.25  g/ml. When tested alone, the minimal inhibitory concentration of assiguxanthone-B was 25  g/ml against B. subtilis. Kielcorin and 2,5-dihydroxybenzoic acid were inactive against both strains. None of the fractions was active against Escherichia coli or Pseudomonas aeruginosa. Viable cells of S. aureus were reduced by a 1-3 log CFU/ml within 12 h after exposure of one to eight times the MIC of the xanthone mixture. It is not known whether the tetrahydroxy-2-prenylxanthone or other components of the xanthone mixture are responsible for the main antibacterial activity or whether additive or synergistic action is involved
Pinheiro
Lucimar
L
Departamento de Farmácia e Farmacologia, Universidade Estadual de Maringá, Maringá, PR, Brasil.
Nakamura
Celso Vataru
CV
Dias Filho
Benedito Prado
BP
Ferreira
Antonio Gilberto
AG
Young
Maria Claudia Marx
MC
Cortez
Diógenes Aparicio Garcia
DA
D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D028084:Clusiaceae; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013997:Time Factors; D014966:Xanthenes / Q000302:isolation & purification / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D014966:Xanthenes