4U1 4u1 (6R)-5-(acetylamino)-3,5-dideoxy-6-[(1R,2R)-1,2,3-trihydroxypropyl]-beta-L-threo-hex-2-ulopyranonosyl-(2->6)-beta-D-gal actopyranosyl-(1->4)-2-(acetylamino)-2-deoxy-beta-D-glucopyranose 4U1