Document Type

Theses, Ph.D


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence


Organic Chemistry

Publication Details

A Thesis presented for the Award of Doctor of Philosophy, Technological University Dublin, November 2020.


Antimicrobial Resistance is a fundamental threat to global health and safety” (WHO, 2016). Nisin, a 34 amino acid lanthipeptide, is currently used as a food preservative worldwide and has been used for decades without significant bacterial resistance having developed. It is an extremely active molecule which kills a range of different bacterial species. However nisin, along with some other similar peptides, suffers from low stability and solubility at physiological pH, which severely restricts its possible use in human and veterinary medicine. This research is concerned with increasing the stability of nisin in physiological pH systems; the stability of the dehydroalanine (Dha) at position 33 was examined as one of the project aims, along with the generation of novel analogues of the nisin tail and also the incorporation of a cyclopropyl amino acid as a Dha bioisostere moiety conserving the native conformation. This derivatisation of the tail region of nisin may increase its stability while preserving its bioactivity.