Table 1.
Selected examples of wet-chemical techniques for ESI-MS detection of reactive species.
| Reactive species | Origin | Wet chemistry reagent | Intended use | Reference |
|---|---|---|---|---|
| Monophosphine norbornene complex | Ring-opening metathesis polymerization (ROMP) of norbornene | Norbornene-CH2P+Ph3Cl−; -CH2N+(CH3)2(CH2Ph) Cl− (as charge-tagged substrate) | Charge tag (+) | [53,72] |
| Pd-containing intermediates | Cu-free Sonogashira (Heck alkynylation) | [p-IC6H4CH2PPh3]+[PF6]− (as charge-tagged substrate) | Charge tag (+) | [100] |
| Organopalladium species | Pd-mediated (Heck) cross-coupling reactions | [p-IC6H4N(CH3)3]+[I]− (as charge-tagged substrate) | Charge tag (+) | [101] |
| Bis(phosphino) palladium species | Pd-catalysed (Sonogashira) cross-coupling reaction | [Na]+[PPh2(m-C6H4SO3)]− (as charge-tagged substrate) | Charge tag (−) | [102] |
| Palladium complex | Suzuki and Heck Phosphine-Free Reactions | Acetate anion bearing an imidazolium cation (ligands) | Charge tag (+) | [103] |
| Neutral radicals | Radical chain reactions | Lewis acids: Sc(Otf)3 | Cationization as [R∙Sc(Otf)2]+ | [12,104] |
| Ru-carbene species | Ru-carbene based olefin metathesis | Alkali-metal salts | Cationization as alkali adducts | [89] |
| Pd hydride; Neutral Pd(II) complex | Pd-catalyzed addition of allenes to organoboronic acids | CH3COOH | Facilitating ESI (–e and −H∙) to form cationic Pd complex | [97] |
| Hydroxyl-sulfonamide | Metabolic bioactivation of sulfonamide | Ascorbic acid | Stabilizer to inhibit oxidation | [99] |
| Reactive metabolites | Electrochemical simulation of oxidative metabolism | Ferrocenylpropionate (FP)-GSH | Trapping agent; Retention tag | [96] |
| Reactive drug metabolites | P450-mediated drug bioactivation | Deuterium labeled bis-methyl GSH esters (GSH(CD3)2) | Trapping agent; Ion-signal sensitizer | [80] |
| Bioactivated intermediates | Bioactivation of xenobiotics | D-Isomer of peptide: gly-tyr-pro-cys-pro-his-pro | Trapping agent | [105] |
| Radical intermediaries | (Glyco-)xidation of phosphatidylethanolamine | 5,5-dimethyl-pyrroline N-oxide (DMPO) | Spin trap | [106] |
| Electrophilic species | P450-mediated drug bioactivation | N-(2-bromocarbobenzyloxy)-GSH (GSH-Br) | Trapping agent | [95] |
| Epoxide metabolites | in vitro metabolic bioactivation | Cob(I)alamin | Trapping agent; Charge tag | [107] |
| Reactive metabolites | P450-mediated drug bioactivation | Stable isotope labeled GSH, KCN and semicarbazide | Trapping agents; Isotopic tagging | [108,109] |
| Reactive metabolites | UGT-mediated drug bioactivation | N-acetylcysteine (NAC) | Trapping agent | [110] |
| Reactive metabolites | P450-mediated drug bioactivation | quaternary ammonium GSH conjugating agent (QA-GSH) | Trapping agent; Semiquantitation tag | [93] |