Antibacterial Flavonoids against Oral Bacteria of Enterococcus faecalis ATCC 29212 from Sarang Semut (Myrmecodia pendans) and its Inhibitor Activity against Enzyme MurA.

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. 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 fosfomicyn being used as positive controls. Two antibacterial compounds isolated from Sarang Semut were identified as two new flavonoids derivates of 1 (10 mg) and 2 (4 mg). Then, both compounds were tested for antibacterial activities against E. faecalis to find inhibition zones, MIC and MBC values, and it was found that their inhibition zones 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, while their MIC and MBC were 156 and 625 ppm for 1 and 625 and 2500 ppm for 2, respectively. In inhibitory murA enzyme activity assay, compounds 1 and 2 were shown to inhibit the enzyme activity by IC50 values of 21.7 and151.3 ppm. The study demonstrated that ethyl acetate fraction of Sarang Semut contained antibacterial flavonoids as active constituents that showed activity against E. faecalis. These results proved the plant's potential in herbal medicine and the development of new antibacterial agent for pathogenic dental caries.