Final Report

1. Project objective:

A continuation of screening project S2020-231, the main objective of this project S2022-231 was to search for novel natural products that can inhibit Mycobacterium tuberculosis (M tb) by inhibiting Mtb RNA Polymerase (RNA-P) which could ultimately lead to a novel TB treatment. More specifically, we search for new natural products related to pseudouridimycin by selecting the assay conditions for RNA-P enzyme assay and by preselecting the producing microorganisms having a gene cluster related to the biosynthesis of pseudouridimycin.

2. Project design:

While Daiichi Sankyo RD Novare provided selection of microorganisms and preparation of fermentation extracts, TB Alliance coordinated with its academic collaborators at the University of Illinois Chicago and Texas A&M University to test these extracts and the fractions in Mtb whole-cell MIC assay and testing extracts and the fractions in RNA-P enzyme assays, respectively. Any hits would be purified and active components would be identified using LC-MS analysis.

3. Results, lessons learned:

Of 134 extracts that were analyzed in both assays, 3 extracts exhibited some activity in both assays. Of those 3 extracts, 72 fractionated samples were shipped for reanalysis in both assays. Some fractions showed activity in both assays; however, after LC-MS analysis they were determined to be analogs of known compounds that could not progress beyond this stage due to established safety concerns. Other fractions did not show strong efficacy in one or both assays. Unfortunately, after careful analysis, we were unable to identify a promising fractionated sample that met the objectives of the project.