Date of Award
Doctor of Philosophy (PhD)
Michio Kurosu, Ph.D.
Scott G. Franzblau, Ph.D. Richard E. Lee, Ph.D. Bernd Meibohm, Ph.D. Duane D. Miller, Ph.D.
MenA inhibitors, Mycobacterium tuberculosis, mycolyl arabinogalactan, Phosphotransferase inhibitors, Pleuromutilin analogs, WecA and MurX inhibitors
New antimycobacterial molecules that kill non-replicating Mycobacterium tuberculosis (Mtb) were identified by screening libraries of synthetic natural products. De novo screening of a 400-membered library of aurachin RE analogs resulted in discovery of UT-317 ((R)-20). UT-317 is a selective vitamin K2 biosynthesis (MenA) inhibitor that killed replicating and non-replicating Mtb at 2.31 μg/mL (MIC) and 0.85 μg/mL, respectively. A 50-membered library of capuramycin analogs was evaluated in their enzymatic inhibitory activities against translocase I (MraY/MurX) and prenyl-phosphate-GlcNAc-1-phosphate transferase (WecA). UT-01320 (45) is identified as a selective WecA inhibitor that kills both replicating and non-replicating Mtb at 1.50 μg/mL (MIC) and 2.58 μg/mL, respectively. UT-01320 killed the intracellular Mtb much faster than the first-line TB drugs such as isoniazid and rifampicin. A strong antimycobacterial agent, UT-800 (64) was identified by screening of a 50-membered library of pleuromutilin derivatives. UT-800 is a protein biosynthesis (50s ribosome) inhibitor which has activity focused against Mtb. UT-800 killed replicating and non-replicating Mtb at 0.83 μg/mL (MIC) and 1.20 μg/mL, respectively. In the course of these works, fluorescent probes, Park’s nucleotide-Nε-C6-FITC (32, for MraY/MurX) and UDP-glucosamine-C6-FITC (46, for WecA) were developed. These fluorescent probes enable us to screen the polyprenyl-phosphate N-acetylhexosamine 1-phosphate transferase enzyme superfamily (e.g. MraY/MurX, WecA, AlgH, and DPAGT1) in high-throughput manner.
Siricilla, Shajila (http://orcid.org/0000-0003-3243-2812), "Discovery of Natural Product-based Antimycobacterial Agents Effective against Non-replicating Bacilli" (2017). Theses and Dissertations (ETD). Paper 434. http://dx.doi.org/10.21007/etd.cghs.2017.0434.