The structure of the capsular polysaccharide from Escherichia coli O8:K87:H19 was investigated by methylation analysis and by one- and two-dimensional 1H- and 13C-n.m.r. spectroscopy. The repeating unit was shown to be a branched pentasaccharide with the structure (formula; see text).
E. coli O8:K87:H19
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6
6,3,4 bDGlcpA 104.67 74.17 77.00 77.52 78.38 ?
6,3,2 Ac 174.64-174.80 22.98
6,3,3 Ac 174.45 21.36
6,3 aLFucpN 97.85 47.88 71.22 77.69 67.00 16.05
6,2 Ac 174.64-174.80 22.98
6,4 bDGlcp 102.24 74.57 76.59 71.51 77.29 62.44
6 bDGlcpN 102.47 56.49 75.67 74.17 75.90 60.47
aDGalp 99.35 69.31 69.03 70.06 68.91 67.64
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6
6,3,4 bDGlcpA 4.417 3.483 3.746 3.848 3.675 -
6,3,2 Ac - 1.97-1.99
6,3,3 Ac - 2.09
6,3 aLFucpN 5.178 4.375 4.908 4.153 4.855 1.306
6,2 Ac - 1.97-1.99
6,4 bDGlcp 4.520 3.221 3.513 3.231 3.439 3.790-3.951
6 bDGlcpN 4.733 3.914 3.948 3.935 3.678 3.877-4.024
aDGalp 5.475 3.792 3.801 3.745 3.890 3.680-3.897
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6
6,3,4 bDGlcpA 104.67/4.417 74.17/3.483 77.00/3.746 77.52/3.848 78.38/3.675
6,3,2 Ac 22.98/1.97-1.99
6,3,3 Ac 21.36/2.09
6,3 aLFucpN 97.85/5.178 47.88/4.375 71.22/4.908 77.69/4.153 67.00/4.855 16.05/1.306
6,2 Ac 22.98/1.97-1.99
6,4 bDGlcp 102.24/4.520 74.57/3.221 76.59/3.513 71.51/3.231 77.29/3.439 62.44/3.790-3.951
6 bDGlcpN 102.47/4.733 56.49/3.914 75.67/3.948 74.17/3.935 75.90/3.678 60.47/3.877-4.024
aDGalp 99.35/5.475 69.31/3.792 69.03/3.801 70.06/3.745 68.91/3.890 67.64/3.680-3.897
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Found 1 record.
Displayed record 1
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