ABSTRACT
The classical bio-assay guided approach is to screen extracts for biological activity and then use an iterative cycle of fractionation/assay/fractionation until the active compound is purified. This is time consuming, often requiring many cycles of fractionation before the compound of interest is purified and requires resources to run the assay after every chromatographic (fractionation) step. Structure elucidation occurs once the pure compound is obtained and, in many cases, known compounds are re-discovered. This project aims to apply 1H NMR in combination with multivariate statistical analysis (PCA) in order to achieve a metabolic profile for natural product fractions, that are active on TB targets. As NMR reveals all compounds containing hydrogen and is quantitative, it can be used to guarantee that all compounds within a fraction are isolated. TB is an infectious disease worldwide, causing death every 20 seconds, and a new drug is urgently needed because of the multi-drug resistance developed by Mycobacterium tuberculosis. The NMR approach is being used to analyse the results of a recent HTS screen against M. tuberculosis H37Rv and the recombinant mycobacterial lipoamide dehydrogenase (Lpd) enzyme, which is involved in M. tuberculosis defence against the host immune system.
