Figure 2. Section of the charge deconvoluted ESI-FT-ICR-MS spectra (acquired in positive ion mode) of 6a,b obtained after 2 d HF treatment of LTA of S. oralis Uo5∆cps and subsequent purification by HIC and GPC (P-10 pool 1 in Fig. S4).

Besides the major molecule 6b with a MW_found of 1030.408 Da (MW_calc: 1030.403 Da), a second compound with one hexose less (6a; MW_found: 868.356 Da; MW_calc: 868.353 Da) was observed in minor amounts as well. For both molecules, variants with a bound alanine or acetyl residue could be identified with very small signal intensity.