Inclusion complexes of V-amylose with undecanoic acid and dodecanol at atomic resolution: X-ray structures with cycloamylose containing 26 d-glucoses (cyclohexaicosaose) as host

V-amylose Structural Characteristics, Methods of Preparation, Significance, and Potential Applications

“…(11) , Godet et al, (5,31) using simulated molecular docking, pointed out that within the Vamylose helix, the H-5 atoms of the glycosyl residues in a six glycosyl residue ring could form van der Waals interactions with fatty acid methylene groups, hence also implying a hydrophobic internal environment. Rappenecker et al (4) and Nimz et al (32) described the intra and intermolecular contacts in V-amylose that are necessary for stability of polymeric and macrocycle 26-D-glucose cycloamylose V-amylose, respectively. They showed that the helical amylose structure and amylose-ligand interaction are stabilized by a series of molecular hydrogen bonds and van der Waals forces between the amylose glucose residues, water molecules and the ligand.…”

“…They showed that the helical amylose structure and amylose-ligand interaction are stabilized by a series of molecular hydrogen bonds and van der Waals forces between the amylose glucose residues, water molecules and the ligand. (4,32) Nimz et al (32) demonstrated that the intrahelical amylose-ligand interaction is dominated by hydrogen-to-hydrogen van der Waals forces between the hydrogens bonded to the 3 rd and 5 th carbon of glucose molecules with the hydrogen from the aliphatic chain C-H for the cycloamylose V-amylose helix. The formation of the inclusion complexes therefore involves hydrophobic forces that enable transfer of a hydrophobic ligand component, such as the aliphatic fatty acid chain from a 4 hydrophilic polar phase, into the hydrophobic environment within the amylose helix cavity.…”

“…The formation of the inclusion complexes therefore involves hydrophobic forces that enable transfer of a hydrophobic ligand component, such as the aliphatic fatty acid chain from a 4 hydrophilic polar phase, into the hydrophobic environment within the amylose helix cavity. (31,33,34) Along glucose residues in the amylose chain, the V-amylose is stabilized by intramolecular hydrogen bonds (H-O.…H-O) involving O2(1)…O3(2) (4,32) with an extra O2 (1)…O6(7) in polymeric V-amylose (4) (the number after O indicates the carbon number in D-glucose to which the oxygen is covalently bonded while the number in parenthesis indicates the glycosyl residue number/position in the amylose chain). The intrahelical channel may contain water molecules that are hydrogen bonded to each other but not to the amylose.…”

“…(4) Water mediated interhelical hydrogen bonding occurs in a bidentate mode (glycosyl-O…H-O-H…O-glycosyl) to glucosyl residues at O5 and O6 or at O2 and O3 in cycloamylose helices. (32) The interhelical hydrogen bonds have been shown to occur between water molecules and O2, O3, O5, and O6 of the glucosyl residues in polymeric V-amylose. (4) Interhelical space water-water hydrogen bonding further occurs between the water molecules linked to the helix, such as the O-W… W-O (W = H-O-H) bonds reported by Rapnecker et al (4) This leads to an extensive network of hydrogen bonds that can enable the build up of larger Vamylose structures or crystals.…”

“…The arrangements could probably be explained to result from the different ligand aliphatic chain stereo-conformations and head group sizes used since it was suggested that aliphatic chains in an all-trans conformation and alcohols with slim head groups can smoothly fit in the V-amylose channel. (32) The V-amylose helix diameter is controlled by the size of the complexing agent, leading to helices with 6, 7 or 8 glucosyl residues-per-turn. (4,13,(42)(43)(44) Six glycosyl residues per turn are for lipids or linear alcohols, 7 for branched chain alkyl compounds, while 8 residues are for more bulky compounds.…”