Fig. 4. LC-ESI-MS traces for (A) translation, (B) elimination, (C) conjugate addition of 1-thio-β-d-glucose, (D) conjugate addition of 4-carboxybenzyl thiol, and (E) DSG cyclisation then conjugate addition of 1-thio-β-d-glucose, all with the test peptide K2,11-C6-TEV-GS (sequence as shown at top, with cysteine emphasised in bold and the lysines used for cyclisation in red). Traces are extracted ion chromatograms for the relevant [M + 2H]2+ species (1285.0–1286.5, 1268.0–1269.5, 1352.0–1353.5, 1366.0–1367.5, 1414.0–1415.5, respectively; TIC traces in ESI Fig. S10†). Inset: expansions of the partially-resolved peaks for conjugate addition product diastereomers.
