The crystal structure of A-starch: is it double helical?

On Crystallinity in Cereal and Tuber Starches

“…The positions of the starch diffraction bands, as related to the zero diffraction angle thus determined, were measured on the intensity spectra by the use of the image analysis system, and also checked by hand, directly from the X-ray films, using a sliding calliper. The d-spacings obtained here agreed well with those reported in literature [4][5][6]. Hence, the attribution of the planes of reflection was based on these works, without further analysis.…”

Crystal Structure of B-Amylose

“…Many structural studies have been done on amylose so far. Wu and Sarko reported that, in forms A 1,2 and B, 5 the molecule assumes the right-handed double strand helix and packs in antiparallel manner, while Imberty et al reported that, in forms A 6,7 and B, 8 the molecule assumes the left-handed double strand helix and packs in parallel manner. On the other hand, in form V, the moelcule assumes left-handed single (6/1)helix.…”

“…Amylose is α-1,4- d -glucan: a linear polymer of α-1,4- d -glucose and a main component of starch. − The polymorphs in amylose are classified as A, B, C, and V in the same way as starch. Form A is found in corns and form B is found in potatoes.…”

Self-Association of Aromatic Oligoamide Foldamers into Double Helices in Water

“…The self-aggregation of organic oligomeric or polymeric molecular strands into multiple helices is a commonly observed phenomenon in nature . Chemists have mimicked this process in a variety of systems and shown that artificial organic oligomers are also able to associate into multistranded structures using original recognition motifs (a vast array of helicates involving metal coordination also exist and are not being considered here).…”