Isolation and characterisation of disodium (4-amino-4-deoxy-beta-L- arabinopyranosyl)-(1-->8)-(D-glycero-alpha-D-talo-oct-2-ulopyranosylona te)- (2-->4)-(methyl 3-deoxy-D-manno-oct-2-ulopyranosid)onate from the lipopolysaccharide of Burkholderia cepacia.