title: Polymorphism of monolayer lipid membrane structures made from unsymmetrical bolaamphiphiles.
abstract: The crystal structures of synthetic unsymmetrical 1-glucosamide- and 1-galactosamide bolaamphiphiles, 13-[(beta-d-glucopyranosyl)carbamoyl]tridecanoic acid (1) and 15-[(beta-d-galactopyranosyl)carbamoyl]pentadecanoic acid (2), respectively, were elucidated by single-crystal X-ray analysis. The space group for 1 is P2(1), Z=2 with cell dimensions: a=8.6816(9), b=4.8578(5), c=26.250(3)A, beta=91.460(2) degrees ; that for 2P2(1), Z=2 with cell dimensions: a=4.90(1), b=40.139(1), 6.289(1)A, beta=106.48(1) degrees . The glucopyranosyl and galactopyranosyl rings in 1 and 2, respectively, take a (4)C(1) chair conformation. In the crystal lattice, the 1-glucosamide 1 forms a symmetrical monolayer lipid membrane (MLM) structure in which the molecules are packed in an antiparallel fashion, while 1-galactosamide 2 has an unsymmetrical MLM with parallel molecular packing. The stereochemistry of the sugar hydroxy group proved to affect their hydrogen-bonding networks and induce the polymorphism of the MLM.
authors.affiliation: Nanoarchitectonics Research Center (NARC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan. m-masuda@aist.go.jp
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Masuda
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoza
authors.forename: Toshimi
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D000577:Amides / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D005690:Galactose / Q000737:chemistry* / Q000378:metabolism; D005947:Glucose / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D008563:Membrane Lipids / Q000737:chemistry*; D008956:Models, Chemical; D008968:Molecular Conformation; D015394:Molecular Structure; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000577:Amides; D008563:Membrane Lipids; D013501:Surface-Active Agents; D005947:Glucose; D005690:Galactose