Antibacterial activities of the methanol extracts and compounds from Uapaca togoensis against Gram-negative multi-drug resistant phenotypes

• The antibacterial activity of parts and compounds of Uapaca togoensis was evaluated.
• Crude extracts from the fruits extract displayed the best antibacterial spectrum.
• Pomolic acid is the major antibacterial constituents of the fruits of Uapaca togoensis

Uapaca togoensis is a medicinal plant used in sub-Saharan Africa to treat various ailments including bacterial infections. In the present study, the methanol extracts from the fruits (UTF), bark (UTB) and leaves (UTL) of this plant as well as six compounds previously isolated from UTF were tested for their antimicrobial activities against a panel of Gram-negative bacteria including multidrug resistant (MDR) phenotypes.As results of the minimal inhibitory concentration (MIC) determinations, the fruit extract displayed the best activity, the MIC values below 100 μg/mL being recorded on 25.0% of the 28 tested bacteria. The lowest MIC value of 8 μg/mL with this extract against Providencia stuartii PS2636. Pomolic acid (4) inhibited the growth of 100% of the tested bacteria with MICs ranged from 32 to 256 μg/mL. The present study demonstrates that U. togoensis can be explored more for the development of herbal drugs to tackle MDR bacterial infections. Compound 4 is the main antibacterial constituent of the fruit of the plant.