Synthesis and Purification of N-LfB6

Many pharmaceuticals have been rendered useless by growing antimicrobial resistance. As bacteria evolve and adjust to the drugs administered to fight them, it is increasingly difficult to find new working drugs. One potential solution to this is using non-natural antimicrobial mimics. I am developing and purifying such a mimic, a peptoid, to determine its effectiveness to that of the peptide counterpart. Peptoids are very similar in structure to peptides, though the key difference being the side chains are attached to the nitrogen, rather than the α-carbon. This difference removes backbone chirality from the peptoid, increases stability, and makes the compounds protease resistant. Protease resistance leads to higher bioavailability (uptake of the drug by the host), which is a problem in antimicrobial peptides. Thus, peptoids should retain toxicity to bacteria longer, remain effective in small doses, and thus lack many side effects that accompany large doses of other drugs. N-LfB6 is the peptoid mimic of an antimicrobial peptide Lactoferricin B6 (RRWQWR-NH₂). This peptoid was chosen because there is available data on the petptide counterpart LfB6 and its cytotoxicity. After synthesis and purification of the peptoid, the project will move forward with testing N-LfB6 against its peptide counterpart’s cytotoxicity. From there, the hemolytic ability of both compounds will be tested. If need be, the sequence of the peptoid will be altered to improve cytotoxicity and/or reduce hemolytic ability.