Elucidation of two O-chain structures from the lipopolysaccharide fraction of Agrobacterium tumefaciens F/1

Agrobacterium tumefaciens F/1 produces two different O-chains, both are constituted of rhamnose and glucosamine: the less abundant has a linear disaccharidic repeating unit 3)-α-l-Rhap-(1 → 3)-β-d-GlcpNAc-(1→ and the second one 4)-α-l-Rhap-(1 → 3)-β-d-GlcpNAc-(1→. The two intact antigenic moieties were studied in mixture by 2D NMR. Additional supporting data were obtained by periodate degradation, the major component was cleaved selectively, leading to a glucosamine glycoside, whereas the minor one was recovered unaffected.