SUPPORTING EXPERIMENTAL PROCEDURES
Methods S1: NMR spectroscopy
The glycosides were freeze dried and solved in D2O (99.996% D%; Sigma-Aldrich Austria,
Vienna, Austria) to concentrations of ~120 µg 600 µL-1. Solutions were transferred into 5 mm
NMR sample tubes (Promochem, Wesel, Germany) and the spectra have been recorded on a
Bruker DRX-600 AVANCE spectrometer (Bruker, Rheinstetten, Germany) at 600.13 MHz
(1H) using the Bruker Topspin 2.1 software. The 1H NMR spectra were measured with
presaturation, acquisition of 32k data points and a relaxation delay of 1.0 s resulting in spectra
with a range of 7200 Hz. 2D Homonuclear COSY, TOCSY (100 ms mixing time), and
ROESY (400 ms mixing time) spectra were measured by 384 experiments with 2048 data
points and appropriate number of scans using standard Bruker programs. Linear forward
prediction, sinusoidal multiplication in both dimensions and Fourier transformation lead to
2D-spectra with a range of 7200 Hz in both dimensions. All samples have been measured at
298.1 K and the chemical shifts were referenced to external acetone (δH 2.225 ppm).
Methods S2: Chemical derivatization for GC-MS analysis
Deuteropermethylation of the freeze-dried side chain A enriched fraction was performed
using iodomethane-D3 (Aldrich) according to the procedure developed by Ciucanu and Kerek
(1984). The methylated glycan was purified on a C18 Sep-Pak as previously described
(Morelle and Michalski, 2007) and carboxylreduced at room temperature overnight by adding
500 µL of 1 M lithium triethylborohydride in tetrahydrofuran (Super-hydride solution,
Aldrich). The carboxylreduction was terminated by adding acetic acid and borates were
eliminated under a stream of nitrogen in presence of methanol containing 5% v/v acetic acid.
After Sep-Pak purification, the sample was remethylated using iodomethane-D3 and purified
on a C18 Sep-Pak. The sample was then submitted to hydrolysis using trifluoroacetic acid,
NaBD4 reduction, and acetylation before analysis of the partially methylated alditol acetates
as previously described (Morelle and Michalski, 2007).