Inulin

(→2)-ß-D-fructan(1→). The chain is terminated by a (1→2)-linked α-D-glucopyranosyl unit [2].

Flexible molecule, tend to be a right-hand twist [4]. ¹H NMR experiments has shown inulin to form a 5-fold helix at DP>8. Below 8, does not adopt this conformation [1]. ¹³C NMR experiments has not been able to show this conformation [1]. Conformational analysis, X-ray and electron diffraction has suggested both left and right handed five-fold helices [1]. Hydrated and semihydrated inulin has been shown to adopt a six-fold helix conformation [1].