For the charges obtained from α-1,4-D glucopyranose structures with attached side chains, only the 2-hydroxypropyl side chains and the connecting (ether like) oxygen atom had their charges fitted and the remaining charges of glucopyranose were fixed to their original GLY-CAM06 values. For the charges obtained from the 1-methoxypropan-2-ol model system, we fixed the partial charge on the carbon atom in the methyl group (Q meth , Figure ) to the GLYCAM06 value to +0.276 for R 1 (4GX), +0.272 for R 2 (4GY) and +0.264 for R 3 (4GZ)