The antimicrobial activity of 3,5,7-trihydroxyflavone isolated from the shoots of Helichrysum aureonitens.
Extracts from Helichrysum aureonitens are used topically by the indigenous people of South Africa against infections. The antimicrobial activity-guided fractionation by bioautography of the acetone extract from the aerial parts of H. aureonitens led to the isolation of 3,5,7-trihydroxyflavone (galangin). Evaluation of the antibacterial activity of the compound against ten randomly selected bacteria indicated significant activity against all the Gram-positive bacteria tested with the minimum inhibitory concentration (MIC) ranging from 0.1 to 0.5 mg/ml. The compound was not active on Gram-negative bacteria except for Enterobacter cloacae which was significantly inhibited at an MIC of 0.1 mg/ml. Galangin indicated considerable activity against the fungi tested with the exception of Cladosporium herbarum. Penicillium digitatum and P. italicum appeared to be particularly susceptible at a concentration of 0.01 mg/ml.
Afolayan
A J
AJ
Department of Botany, University of Pretoria, South Africa.
Meyer
J J
JJ
D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D013019:South Africa
D000900:Anti-Bacterial Agents; D005419:Flavonoids; D010936:Plant Extracts; C037032:galangin