Theoretical study of hyaluronan disaccharides


The aim of our study is to determine the characteristic structures of hyaluronan disaccharides and their stabilizing factors. Two types of disaccharides were examined, the β-D-glucuronic acid-(1->3)-β-D-N-acetylglucosamine (further acid-amin) and β-D-N-acetylglucosamine-(1->4)-β-D-glucuronic acid (further amin-acid) where both the free acids and anions, all together four different constitutional isomers, were modeled. These disaccharides can exist in numerous conformations determined by the hydrogen bonds formed. We searched for the most stable conformers, which are shown in the tables below. These computations have been done at the B3LYP/6-31G** level of theory. The hydrogen bond lengths are given in angstroms, while the relative energies in kJ.mol-1.


Amin-Acid structures

Anion form

0,00 kJ.mol-1

4,45 kJ.mol-1

13,97 kJ.mol-1

18,19 kJ.mol-1

92,92 kJ.mol-1

97,42 kJ.mol-1


Free Acid form

0,00 kJ.mol-1

4,64 kJ.mol-1

5,58 kJ.mol-1

5,96 kJ.mol-1

7,07 kJ.mol-1

9,36 kJ.mol-1

12,17 kJ.mol-1

16,50 kJ.mol-1

20,50 kJ.mol-1

22,30 kJ.mol-1

30,17 kJ.mol-1

42,76 kJ.mol-1


47,25 kJ.mol-1



Acid-Amin structures


Anion form

0,00 kJ.mol-1

5,45 kJ.mol-1

14,51 kJ.mol-1

22,20 kJ.mol-1

27,14 kJ.mol-1

37,00 kJ.mol-1

41,26 kJ.mol-1

42,51 kJ.mol-1


62,58 kJ.mol-1



Free Acid form


0,00 kJ.mol-1

3,91 kJ.mol-1

6,56 kJ.mol-1

10,65 kJ.mol-1

11,65 kJ.mol-1

23,92 kJ.mol-1

32,29 kJ.mol-1

42,82 kJ.mol-1

45,07 kJ.mol-1

47,69 kJ.mol-1