Amylodextrins

Amylodextrins from waxy-maize starch (A type) and potato starch (B type) retain the same diffraction pattern as that of the parent starch. On separation of a starch to give an amylodextrin, the... 

It was Brown and Morris (15) in 1888 who employed Raoult s method. They reported a value of 30,000 for the molecular weight of amylodextrin, a degradation product of the hydrolysis of starch. Subsequently Lintner and Dull (16) also using cryoscopy reexamined amylodextrin, and reported the molecular weight as 17,500. In a third paper, Rodewald and Kattein (17) in 1900, measured the molecular weight of starch by osmotic pressure experiments carried out on aqueous solutions of starch iodide. They obtained somewhat higher molecular weights, 36,700 and 39,700. 

Donovan, J. W. and Mapes, C. J. (1980). Multiple phase transitions of starches and Nageli amylodextrins. Starch/Stdrke 32,190-193. 

Example 4 Using ACE to Observe the Complexation Behavior of Amylodextrin Oligomers and Selected Pharmaceuticals... 

Amylose and amylodextrins have been used in the food and pharmaceutical industries as excipients. Recently, they have been explored as chiral selec-... 

Fig. 13 Electropherograms of amylodextrins with different pharmaceuticals. (A) ibuprofen, (B) ketoprofen, (C) furosemide, (D) warfarin. Electrophoretic conditions 20 mM phosphate buffer, pH = 7.0, ionic strength 18.3 mM. Other conditions are the same as for Figure 12. (From Ref. 75.)...

M Hong, H Soini, A Baker, MV Nothy. Complexation between amylodextrin oligomers and selected pharmaceuticals measured through capillary electrophoresis. Anal Chem 70 7590-7597, 1998. 

Jane, J. L., Robyt, J. F. (1984). Structure studies of amylose V complexes and retrogradaded amylose by action of alpha amylase, a new method for preparing amylodextrins. Carbohydr. Res., 132, 105-110. 

Te Wierik GH, Eissens AC, Lerk CF. Preparation, characterization, and pharmaceutical application of lineardextrins. III. Drug release from fatty suppository bases containing amylodextrin. Pharm Res 1994 11(1) 108 110. 

Amylodextrin is an intermediate product of acid degradation(hydrolysis) of starch. It is... 

Figure 5.4 X-ray powder diffractogram recorded for (a) A-type amylodextrins and (b) B-type amylodextrins grown as spherulites. X-ray fiber diffraction patterns (fiber axis vertical) for (c) A-amylose (fiber spacing 1.04 nm) and (d) B-amylose (fiber spacing 1.05 nm). (Reproduced with permission from references 30 and 31). Microcrystal of (e) A-starch and (f) B-starch observed by low dose electron microscopy. Inset the electron diffraction diagrams recorded under frozen wet conditions (e). (Reproduced with permission from references 32 and 34)...

Amylodextrin is the homogeneous product of prolonged hydrolysis of starch below Tgz, terminating in the crystalline equivalent of Avicel and approximating 25 glucose monomers. The hydrolysis is normally at room temperature over intervals of months, wherein the amorphous regions are degraded and the starch crystallites are left intact. Unlike Avicel crystallites, starch crystallites may be disrupted by stress (Kerr, 1950). 

Szejtli, J. (1991). Biotechnology of Amylodextrin Oligosaccharides, ACS Symposium Series 458. Am. Chem. Soc., Washington, DC. 

Kainuma, K., and French, D. 1972. Naegeli amylodextrin and its relationships to starch granule structure. II. Role of water in crystallization of B-starch. Biopolymers 11, 2241. 

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