Table 2.
MICs and MBCs in µg/mL of fractions and compounds isolated from the leaf (APL) of Acacia polyacantha and chloramphenicol against a panel of selected Gram-negative bacteria.
| Bacterial strains | Tested samples MIC and MBC (in bracket) values (µg/mL) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Fractions from APL | Isolated compounds | Reference antibiotic | |||||||
| APLa | APLb | APLd | 4 | 5 | 6 | 7 | 8 | chloramphenicol | |
| Escherichia coli | |||||||||
| ATCC8739 | - | 16 (-) | 16 (-) | - | - | - | - | 32 (-) | 2 (64) |
| AG102 | - | 128 (-) | 64 (-) | 256 (-) | - | 128 (-) | - | 32 (-) | 32 (256) |
| Enterobacter aerogenes | |||||||||
| ATCC13048 | - | 256 (-) | 8 (-) | 128 (-) | 64 (-) | - | - | 32 (-) | 16 (128) |
| EA27 | - | - | 128 (-) | 256 (-) | 256 (-) | - | - | - | 32 (256) |
| Klebsiella pneumoniae | |||||||||
| ATCC11229 | 16 (-) | 64 (-) | 16 (-) | 64 (-) | 32 (-) | - | - | 32 (-) | 32 (256) |
| KP55 | - | 16 (-) | 64 (-) | 128 (-) | 256 (-) | - | 128 (-) | 32 (-) | 64 (256) |
| Pseudomonas aeruginosa | |||||||||
| PA01 | - | 128 (-) | 64 (-) | - | - | - | - | - | 64 (-) |
| PA124 | - | 256 (-) | 64 (-) | 256 (-) | 128 (-) | - | - | 32 (-) | 256 (-) |
| Providencia stuartii | |||||||||
| ATCC29916 | - | 128 (-) | - | - | - | - | - | 64 (-) | 64 (256) |
(-): > 512 µg/ml for fractions or > 256 µg/ml for compounds; APL: leaf extract; APLa, APLb, and APLd are fractions from APL; 1: stigmasterol, 2: β-amyrin, 3: 3-O-β-D-glucopyranosylstigmasterol, 4: 3-O-methyl-D-chiro-inositol, 5: epicatechin, 6: quercetin-3-O-glucoside, 7: 3-O-[β-D-xylopyranosyl-(1→4)-β-D-galactopyranosyl]-oleanolic acid, 8: 3-O-[β-galactopyranosyl-(1→4)-β-D-galactopyranosyl]-oleanolic acid; MIC values in bold: significant antibacterial effect [18]. Notes: MICs of fraction APLc > 512 µg/ml and MIC of compounds 1, 2, 3 were > 256 µg/ml in all tested bacteria.