Methyl (4-bromobenzoyl)-L-cysteinate is a chemoselective thiol probe for detection of electrophilic metabolites. As it is often difficult to isolate low-abundance natural products from extracts, metabolities with bioactivity or therapeutic potential may be missed. Castro-Falcón, et al developed a reactivity-guided approach using thiolate probes to discover electrophilic natural products - a cysteine-based probe and thiophenol-based probe. Both consist of
- A chemoselective reagent for covalent reactivity with a pharmacophore,
- A conspicuous UV/VIS or mass spectrometric (MS) tag,
- A linker between the tag and reagent. Methyl (4-bromobenzoyl)-L-cysteinate contains a bromine MS tag and phenyl bromide UV tag that was demonstrated to chemoselectively label enone-, β-lactam-, and β-lactone-based natural products.
Complementarily, a thiophenol probe (cat#
125237) with a chlorine MS tag and phenyl chloride UV tag labeled epoxide-based natural products. These probes can be used in diverse extracts (bacterial, fungal, plant) to chemically faciliate access to high-value metabolites.
