Antimicrobial activity of Dalbergia melanoxylon extracts.

The antibacterial and antifungal properties of the methanol, citric acid, aqueous, dichloromethane and petroleum ether extracts from the bark of Dalbergia melanoxylon were determined by using seeded agar plates with wells into which were placed the extract, and flasks of yeast extract and sucrose broth for mycelial growth of the fungi. After incubation for 24 h, the diameter of the inhibition zone was measured for the antibacterial tests and after 7 days, the dry weight of the mycelia was measured and a percentage of inhibition calculated using controls where no extracts were added. The results obtained showed that the citric acid extract exhibited strongest antimicrobial activity. The ethanol fraction showed significant antibacterial activity but was not significantly active against fungi. The dichloromethane extract exhibited no activity against bacteria but showed notable activity against fungi. The petroleum ether fraction showed no antimicrobial activity.