Figure 4

Negative ESI LC–MS monitoring relative conversion to the PseB and PseC products in deuterated buffer with UDP-GlcNAc 4 (a) after 10 min with equal concentrations of PseB and PseC, (b) after 10 min with a PseB:PseC concentration of 1:5, (c) after 2 h with equal concentrations of PseB and PseC or (d) after 2 h with a PseB:PseC concentration of 1:5.