Glycosidase-catalysed synthesis of oligosaccharides: trisaccharides with the α- D -gal-(1 → 3)- D -gal terminus responsible for the hyperacute rejection response in cross-species transplant rejection from pigs to man

α-Galactosidases from Coffea arabica, Aspergillus niger and A. oryzae catalyse the transfer of α-galactosyl residues on to lactose thioglycosides to give 1 → 3 and 1 → 6 linked trisaccharides, including an unusual branched trisaccharide 11 and the isoglobotriose glycoside 4, which, as ‘linear B type 6’, has been recognised as of the type responsible for the hyperacute rejection response in pig-to-man xenotransplantation.