Background:
A significant number of antibiotics are known to inhibit peptidoglycan synthesis
in the cross-linking stage, while the drug fosfomycin is the only one known to inhibit MurA.
Escalated antibiotic resistance has had an impact on the efficacy of fosfomycin, thus demanding the
discovery of suitable substitutes with improved potential for MurA inhibition. The aim of this work
is to isolate antibacterial compounds from Sarang Semut (Myrmecodia pendans) and to evaluate their
antibacterial activity against pathogenic oral bacteria of Enterococcus faecalis ATCC 29212 and inhibitory
activity against MurA enzyme.
Methods:
The antibacterial compounds from Sarang Semut were isolated by a bioactivity-guided
separation method with various solvents and combination of column chromatography on normal and
reverse phases. The compounds with concentrations of 1000 and 5000 ppm were assessed against
E. faecalis ATCC 29212 by agar well diffusion method, with chlorhexidine and fosfomycin being
used as positive controls.
Results:
Two antibacterial compounds isolated from Sarang Semut were identified as two new flavonoids
derivates of 1 (10 mg) and 2 (4 mg). Both compounds were tested for antibacterial activities
against E. faecalis. MIC values of compounds 1 and 2 were 8.15 and 8.05 mm at 1000 ppm and 8.62
and 8.55 mm at 5000 ppm, respectively. MBC values were 156 and 625 ppm for 1 and 625 and 2500
ppm for 2, respectively. In an inhibitory murA enzyme activity assay, compounds 1 and 2 were
shown to inhibit the enzyme activity by IC50 values of 21.7 and 151.3 ppm.
Conclusion:
The study demonstrated that ethyl acetate fraction of Sarang Semut contained antibacterial
flavonoids as active constituents that showed activity against E. faecalis. These results showed
the plant’s potential in herbal medicine and the development of new antibacterial agent for pathogenic
dental caries.
