Capsular polysaccharides (CPSs) were isolated from O-polysaccharide deficient strains of Burkholderia mallei and Burkholderia pseudomallei using a modified hot phenol/water extraction procedure. Glycosyl composition, methylation, MALDI-TOF MS analyses as well as (1)H NMR spectroscopy including COSY, TOCSY, NOESY, HMBC and HSQC experiments identified the presence of two distinct CPS antigens in the samples exhibiting the following structures: This study confirms the ability of B. mallei to express a 6-deoxy-heptan CPS and represents the first report of a mannan CPS being expressed by these bacterial pathogens.

structure, capsular polysaccharide, Burkholderia pseudomallei, Burkholderia mallei, protective antigen NMR

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
	aDManp	104.8	72.4	80.9	68.9	76.2	63.8


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
	aDManp	5.13	4.22	4.00	3.77	3.82	3.77-3.89


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
	aDManp	104.8/5.13	72.4/4.22	80.9/4.00	68.9/3.77	76.2/3.82	63.8/3.77-3.89

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@H]1[C@H](O)[C@@H](CO)O[C@H](*)[C@H]1O

162.141 g/mol (C₆H₁₀R₂O₅, R = next and previous repeats, not counted in mol weight)