Bioautography with TLC-MS/NMR for Rapid Discovery of Anti-tuberculosis Lead Compounds from Natural Sources

Grzelak, Edyta M.; Hwang, Changhwa; Cai, Geping; Nam, Joo Won; Choules, Mary P.; Gao, Wei; Lankin, David C.; McAlpine, James B.; Mulugeta, Surafel; Napolitano, José G.; Suh, Joo Won; Yang, Seung Hwan; Cheng, Jinhua; Lee, Hanki; Kim, Jin Yong; Cho, Sang Hyun; Pauli, Guido F.; Franzblau, Scott G.; Jaki, Birgit U.

doi:10.1021/acsinfecdis.5b00150

Cited by 44 publications

(14 citation statements)

References 24 publications

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“…Moreover, using chemical methods to pursue biological targets creates incoherency between the methodology and the desired outcome. To overcome this disadvantage, a TLC-based bioautography was introduced [26,27]. The use of TLC in both the GUESS method and bioautography to visualize bioactivity creates seamless transition from chemical based fractionation to biological targets.…”

Section: Resultsmentioning

confidence: 99%

Sweet spot matching: A thin-layer chromatography-based countercurrent solvent system selection strategy

Liu

Friesen

Grzelak

et al. 2017

Journal of Chromatography A

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TLC-based strategies were proposed in 1979 (Hostettmann et al.) and 2005 (Friesen & Pauli; GUESS method) to minimize the number of partitioning experiments required for countercurrent separation (CCS) solvent system selection. As semi-empirical approaches, both proposed that the K values defining the sweet spot of optimal CCS corresponded to a matching Rf value range from the silica gel TLC plate developed in the organic phase of a biphasic or a corresponding monophasic solvent system. Despite their simplicity, there has been an absence of theoretical support and a deficiency of reported experimental evidence. The present study explores the theory required to develop correlations between Rf and K. All theoretical models surmise that the optimal Rf value range should be centered at 0.5. In order to validate the feasibility of the concept of matching Rf and K values, 43 natural products and six solvent system families were investigated. Out of 62 correlations, 45 resulted in matched Rf and K values. Based on this study, practical guidelines for the TLC-based prediction strategy are provided. These approaches will equip CCS users with an updated understanding of how to apply the TLC-based solvent system selection strategy to accelerate a targeted selection of CCS conditions.

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Section: Resultsmentioning

confidence: 99%

Sweet spot matching: A thin-layer chromatography-based countercurrent solvent system selection strategy

Liu

Friesen

Grzelak

et al. 2017

Journal of Chromatography A

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“…A recent report of RC by Grzelak et al may serve as a final example: two isoflavones that were isolated from an actinomycete extract showed >90% purity and MICs of 0.75 and 0.11 μg/mL against M. tb . 25 However, synthesized material of these compounds failed to demonstrate any anti- M. tb activity. TLC-bioautography in combination with MS and NMR confirmed that the isoflavone samples contained a potent cyclic heptapeptide, xylamycin, which had coeluted with the isoflavones in the initial isolation (manuscript in preparation).…”

Section: Discussionmentioning

confidence: 99%

Residual Complexity Does Impact Organic Chemistry and Drug Discovery: The Case of Rufomyazine and Rufomycin

et al. 2018

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Residual complexity (RC) involves the impact of subtle but critical structural and biological features on drug lead validation, including unexplained effects related to unidentified impurities. RC commonly plagues drug discovery efforts due to the inherent imperfections of chromatographic separation methods. The new diketopiperazine, rufomyazine (6), and the previously known antibiotic, rufomycin (7), represent a prototypical case of RC that (almost) resulted in the misassignment of biological activity. The case exemplifies that impurities well below the natural abundance of 13C (1.1%) can be highly relevant and calls for advanced analytical characterization of drug leads with extended molar dynamic ranges of >1:1,000 using qNMR and LC-MS. Isolated from an actinomycete strain, 6 was originally found to be active against Mycobacterium tuberculosis with a minimum inhibitory concentration (MIC) of 2 μg/mL and high selectivity. As a part of lead validation, the dipeptide was synthesized and surprisingly found to be inactive. The initially observed activity was eventually attributed to a very minor contamination (0.24% [m/m]) with a highly active cyclic peptide (MIC ∼ 0.02 μM), subsequently identified as an analogue of 7. This study illustrates the serious implications RC can exert on organic chemistry and drug discovery, and what efforts are vital to improve lead validation and efficiency, especially in NP-related drug discovery programs.

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“…In order to make the results easier to observe, it is sometimes necessary to add a certain amount of tetrazolium salt to the nutrient medium, such as MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), TTC (2,3,5,-Triphenyltetrazolium chloride) or INT (iodonitrotetrazolium chloride). Dehydrogenases of living microorganisms convert these salts into colored formazans, because MTT, INT and other tetrazolium salts are light in color and easy to be converted into darker compounds by bacterial metabolites, thus forming the background color, and, as a result, for MTT, yellow zones of inhibition are observed on a purple background [ 57 ].…”

Section: Biological Applicationsmentioning

confidence: 99%

An Evolving Technology That Integrates Classical Methods with Continuous Technological Developments: Thin-Layer Chromatography Bioautography

et al. 2021

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Thin-layer chromatography (TLC) bioautography is an evolving technology that integrates the separation and analysis technology of TLC with biological activity detection technology, which has shown a steep rise in popularity over the past few decades. It connects TLC with convenient, economic and intuitive features and bioautography with high levels of sensitivity and specificity. In this study, we discuss the research progress of TLC bioautography and then establish a definite timeline to introduce it. This review summarizes known TLC bioautography types and practical applications for determining antibacterial, antifungal, antitumor and antioxidant compounds and for inhibiting glucosidase, pancreatic lipase, tyrosinase and cholinesterase activity constitutes. Nowadays, especially during the COVID-19 pandemic, it is important to identify original, natural products with anti-COVID potential compounds from Chinese traditional medicine and natural medicinal plants. We also give an account of detection techniques, including in situ and ex situ techniques; even in situ ion sources represent a major reform. Considering the current technical innovations, we propose that the technology will make more progress in TLC plates with higher separation and detection technology with a more portable and extensive scope of application. We believe this technology will be diffusely applied in medicine, biology, agriculture, animal husbandry, garden forestry, environmental management and other fields in the future.

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Bioautography with TLC-MS/NMR for Rapid Discovery of Anti-tuberculosis Lead Compounds from Natural Sources

Cited by 44 publications

References 24 publications

Sweet spot matching: A thin-layer chromatography-based countercurrent solvent system selection strategy

Sweet spot matching: A thin-layer chromatography-based countercurrent solvent system selection strategy

Residual Complexity Does Impact Organic Chemistry and Drug Discovery: The Case of Rufomyazine and Rufomycin

An Evolving Technology That Integrates Classical Methods with Continuous Technological Developments: Thin-Layer Chromatography Bioautography

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