TABLE 5.

Mass peaks identified in the charge-deconvoluted ESI FT-ICR mass spectrum of the core oligosaccharide fraction isolated from the LPS of strain N28b4 after acetic acid hydrolysis and gel permeation chromatography^a

Peak no.	Mass (Da)		Proposed structure
	Identified	Calculated
1	2,021.67	2,021.65	Oligosaccharide 3
	2,003.66	2,003.63	Anhydro form
2	2,257.72	2,257.71	Oligosaccharide 3 plus one Ko residue
3	2,101.63	2,101.61	Oligosaccharide 3 plus one phosphate residue
	2,083.69	2,083.60	Anhydro form
4	1,813.56	1,813.55	KdoHep3HexA2Hex3HexN
	1,795.55	1,795.54	Anhydro form
5	2,197.70	2,197.68	KdoHep5HexA2Hex3HexN
	2,179.68	2,179.67	Anhydro form
6	1,893.43	1,893.52	KdoHep3HexA2Hex3HexNP
	1,875.51	1,875.51	Anhydro form
7	2,337.69	2,337.68	Oligosaccharide 3 plus 1 Ko residue and P residue

^aListed are monoisotopic masses of the neutral molecule. The peaks are given in descending order of intensity. The peak numbers are as depicted in Fig. 6. Additional sodium and potassium adducts (+22 and +38 Da, respectively) found in the spectrum are not listed.