1 research outputs found
Molecular Dynamics Study of Anhydrous Lamellar Structures of Synthetic Glycolipids: Effects of Chain Branching and Disaccharide Headgroup
Glycolipids form materials of considerable potential
for a wide
range of surfactant and thin film applications. Understanding the
effect of glycolipid covalent structure on the properties of their
thermotropic and lyotropic assemblies is a key step toward rational
design of new glycolipid-based materials. Here, we perform molecular
dynamics simulations of anhydrous bilayers of dodecyl β-maltoside,
dodecyl β-cellobioside, dodecyl <i>β-</i>isomaltoside,
and a C<sub>12</sub>C<sub>10</sub> branched β-maltoside. Specifically,
we examine the consequences of chain branching and headgroup identity
on the structure and dynamics of the lamellar assemblies. Chain branching
of the glycolipid leads to measurable differences in the dimensions
and interactions of the lamellar assembly, as well as a more fluid-like
hydrophobic chain region. Substitution of the maltosyl headgroup of
βMal-C<sub>12</sub> by an isomaltosyl moiety leads to a significant
decrease in bilayer spacing as well as a markedly altered pattern
of inter-headgroup hydrogen bonding. The distinctive simulated structures
of the two regioisomers provide insight into the difference of ∼90
°C in their observed clearing temperatures. For all four simulated
glycolipid systems, with the exception of the <i>sn-</i>2 chain of the branched maltoside, the alkyl chains are ordered and
exhibit a distinct tilt, consistent with recent crystallographic analysis
of a branched chain Guerbet glycoside. These insights into structure–property
relationships from simulation provide an important molecular basis
for future design of synthetic glycolipid materials