Antibacterial Compounds Towards Staphylococcus aureus and Escherichia coli of the Stem Bark of Inocarpus Fagigerus FoSB

Abstract

This study aimed to screen the antibacterial compounds of S. aureus and E. coli on the stem bark of Inocarpus fagiferus Fosb. Extraction of active antibacterial compounds by maceration and partitioning, antibacterial tests were carried out by diffusion method, separation of compounds by column chromatography method, and identification of active fractions using LSMS/MS. The results of maceration of 350 g of Inocarpus fagiferus Fosb stem bark produced 22.97 g of methanol viscous extract which was able to strongly inhibit the growth of S. aureus bacteria (14.75mm) and medium inhibit (8.50 mm) towards E. coli. The partition results of the methanol concentrated extract respectively with n-hexane, chloroform, n-butanol, and water yielded 0.01; 0.01; 2.75, and 0.07 g extracts. Based on extract weight only n-butanol extract allows further separation. The result of antibacterial activity has shown a strong inhibition zone toward S. aureus and E. coli (16.50 mm) and with a minimum inhibitory concentration (MIC) of 5%. The result of separation n-butanol extract by gradient column chromatography (silica gel 60; methanol: chloroform (5:5; 6:4; 7:3; 8:4; 9:1; and 10:0)) yielded 4 fractions (FA, FB, FC, and FD) with FC the most active antibacterial toward S. aureus and E. coli with an inhibition zone 7.25 mm and 6.25 mm respectively at 5%. The results of LCMS/MS show 5 identified compounds known are maltol, nicotinamide, bioachanin A, L-proline, and 2,3-diamino propionic acid, as well as one unidentified compound with a molecular weight of 95.8066 g/mol. Maltol, nicotinamide, bioachanin A, and L-proline are compounds potents to inhibit the growth of S. aureus and E. coli bacteria.