LC-MS detection of the SqoD reaction product 6-dehydroglucose
(A) HPLC elution profiles of the DNPH derivatized products of the SqoD reaction, monitoring the absorbance at 360 nm, showing product peaks for 1 and 2 in the full assay, corresponding to two stereoisomers of DNPH-6-dehydroglucose.
(B) Extracted ion chromatograms (m/z (−) 356.9, the predicted mass of the DNPH-6-dehydroglucose monoanion), showing the same two product peaks 1 and 2.
(C–E) The ESI m/z (−) spectrum of the region spanned by three peaks in Figure 3B, showing a species with m/z (−) 356.9 corresponding to different isomers of DNPH-6-dehydroglucose (two possible isomers are depicted). See also Figure S5.