Preferential eradication of gram-negative bacteria using peptide surrogates: cisions & reflections

Short surrogates of the pentapeptide K-A-A-A-K, centered on Freidinger’s lactam, were applied to eradicate E.coli (Gram-negative bacteria) and S. Aureus (Gram-positive microbe). It was found that it was easier to eliminate the gram-positive bacteria, which was influenced by the N-methylation of the amide nitrogen of 30 →31 (Table). However, The N-methylated surrogates were more efficient in eradicating the E. coli than the S. Aureus samples. We were able (Figure 14) to show that one structural change could make a remarkable difference in the eradication (MIC) of the different bacteria