Get C43 H45 CL N3 O13 1+ = rom = c-1027 aromatized chromophore Get C53 H53 CL2 N8 O17 1+ = vag = vancomycin aglycon Get C66 H77 CL2 N9 O24 2+ = van = vancomycin Get C73 H91 CL2 N10 O26 3+ = vax = 4-epi-vancosaminyl derivative of vancomycin