Table 2. Tolerance of the condensation to biological interfering agents.
| |||
| Entry | Additive (conc) | Normalized 2a integral b (%) | Significance |
| 1 | None | 100 | — |
| 2 | Glutathione (5 mM) | 98 | Biothiols do not interfere |
| 3 | Sucrose (100 µM & 5 mM) | 106/92 c | Boron chelators do not interfere |
| 4 | Lysozyme (100 µM) | 105 | Amino acid side-chains cannot compete with O-alkylhydroxylamine for 2-FPBA |
| 5 | Human serum (20% v/v) | 80 d | Reaction is compatible with complex media |
aTime is approximate since samples are injected directly after mixing.
bDetermined by reverse phase HPLC analysis under neutral conditions.
cThis reaction was also performed by pre-mixing the boronic acid with the sucrose, with no measurable change in conjugation efficiency.
dHuman serum leads to oxidation of the boronic acid to a phenol by a Baeyer–Villiger type reaction. The 80% number represents only the measurement of 2a, when the phenol is included nearly complete mass balance is observed. KPi = potassium phosphate buffer.