COMPLEXES OF STARCHY MATERIALS WITH ORGANIC COMPOUNDS .3. X-RAY STUDIES ON AMYLOSE AND CYCLODEXTRIN COMPLEXES

X-Ray analyses of the complexes of amylose with various organic compounds were carried out. Only two kinds of diffraction patterns were observed in the dried state. The first one corresponds to the helix of amylose consisting of six glucose residues per helical turn (61-helix) and the second to that consisting of seven glucose residues (71-helix). The 71-helix was obtained with a relatively wide range of the size of the complexing agents, 4.5˜6.0 Å in diameter of cross section. Mutual transitions between both helices were made possible by displacing the contained agent with one of the other kinds. During the transition courses, the helix with a fractional number of glucose residues could not be seen. It is, hence, infered that the helix is stabilized by hydrogen bonds between individual helical loops. The diffraction patterns of cyclodextrin complexes were also examined. Under suitable conditions α- and β-dextrins can produce complexes having analogous crystalline structures of 61-helix and 71-helix amyloses, respectively. This is confirmatory evidence for the helical structure of amylose. © 1969 Taylor and Francis Group LLC.