TLC-bioautography linked with guess: A truely targeted active compound isolation process

In order to optimize the isolation procedure of anti-TB lead compounds, a truly targeted isolation approach was developed, which aligns (HP)TLC-bioautography with GUESS1 based countercurrent separation (CCS). (HP)TLC-bioautography was specifically developed for Mycobacterium tuberculosis, using the mc2 7000 lux ABCDE strain, while the GUESS method is used to rapidly determine the optimal CCS solvent system. Optimal CCS conditions target the separation of the inhibition zones within a range of optimal CCS partition coefficients referred to as the “CCS sweet spot”, with a corresponding TLC Rf-value ˜0.5. Hereby, the CCS solvent system is chosen on the basis of the Rf-value of the bioactive component(s) rather than the fraction as a whole. This approach accelerates the isolation process and prevents the isolation of non-active metabolites and byproducts. The new TLC-bioautography-GUESS-CCS workflow is demonstrated with the fractionation of an extract from an anti-TB active actinomycete strain. [Funding: NIH R21 AI093919 – 02] 1Friesen & Pauli, G.U.E.S.S. – A Generally Useful Estimate of Solvent Systems for CCC, Journal of Liquid Chromatography & Related Technologies, 2005, Volume 28, Issue17, 2777 – 2806 *Equal contributors