FIG. 3.

NMR spectra. (A) gHSQC spectrum of psicose-borate complex in D₂O. (B) gHSQC spectrum of psicose in D₂O. Chemical shifts are expressed relative to the 4,4-dimethyl-4-silapentane-1-sulfonate signal in D₂O at 0 ppm. αF, α-d-psicofuranose; βF, β-d-psicofuranose; αP, α-d-psicopyranose; βP, β-d-psicopyranose. (C) gCOSY spectrum of the psicose-borate complex in DMSO. Chemical shifts were referenced to tetramethylsilane at 0 ppm. The OH groups at C-3 and C-4 of the psicose-borate complex were absent in the gCOSY spectrum.