Figure 5. Biochemical analysis of products B and C from the PMM126:pPET1 mutant.

(A) MALDI-TOF mass spectra of purified product B (left panel) and of purified product C (right panel) from the PMM126:pPET1 mutant strain. (B) NMR analysis of products B and C. 1D ¹H-NMR spectra (1.8–5.6 ppm) of native (bottom) or per-O-acetylated (upper) glycolipid B (600 MHz, in CDCl₃). The structures of the analyzed compounds are shown below the spectrum and the protons corresponding to the main signals are indicated. The tables summarize the assignments of resonances on the basis of chemical shift correlations deduced from the 2D-COSY spectra of native and per-O-acetylated compounds B and C. Proton resonances shifted by acetylation are written in bold (grey cells). The first column of each table indicates the sugar residue: I, first rhamnosyl residue; II, second rhamnosyl residue; III, terminal fucosyl residue.