title: Acetan:glucomannan interactions--a molecular modeling study.
abstract: X-ray fiber diffraction patterns from deacylated acetan and glucomannan (konjac mannan) blends are diagnostic of good orientation and modest polycrystallinity. The meridional reflection on the sixth layer line suggests that the binary complex is a 6-fold helix of pitch 55.4 A. A molecular modeling study incorporating this information reveals that a double helix in which one strand is acetan and the other glucomannan is stereochemically feasible. While the backbone and side groups are sufficiently flexible to allow the chains to associate with the same or opposite polarity, the parallel model is superior in terms of unit cell packing. The results are compatible with the observed synergy; namely the weak gelation behavior of the complex. The molecular model can be generalized for the binary system when acetan is replaced by xanthan or glucomannan by galactomannan.
authors.affiliation: Whistler Center for Carbohydrate Research, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN 47907-2009, USA. chandra@purdue.edu
authors.forename: Rengaswami
authors.initials: R
authors.lastname: Chandrasekaran
authors.forename: Srinivas
authors.initials: S
authors.lastname: Janaswamy
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Morris
mesh_terms: D000107:Acetylation; D000465:Algorithms; D001665:Binding Sites; D002236:Carbohydrate Conformation; D003198:Computer Simulation; D005936:Glucans / Q000737:chemistry; D006860:Hydrogen Bonding; D016018:Least-Squares Analysis; D008351:Mannans / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification; D014961:X-Ray Diffraction
chemical_list: D005936:Glucans; D008351:Mannans; D011135:Polysaccharides, Bacterial; C068545:acetan; C022901:(1-6)-alpha-glucomannan