Self-Assembled Nanostructures of a Cholesterol-Saccharide Conjugate which Acts as an Amphiphilic Gelator of Organic Solvents

New cholesterol-saccharide conjugate gelator N-cholesteryl succinyl glucosamine (1) was synthesized and its gelation ability was evaluated in organic solvents in this study. It could gelate 1-butanol, iso-butanol, 4-heptanol, cyclohexanol and 1-octanol under the concentration of 5.0 mg/mL. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), circular dichroism (CD) and small-angle X-ray diffraction (SAXRD) were used to analyze the aggregation mode of 1 in the organogel phase. 1 exhibited a fibrous structure composed of thin micellar fibrils with ca.9∼10 nm diameters and these fibrils were packed into a disordered hexagonal mesophase structure with an interlayer distance of 8.01 nm. CD spectra showed that 1 adopted the helical arrangement in the aggregation. A hierarchical self-assembly model was proposed to explain the transition from molecular to primary and secondary structure. Moreover, sol-gel polymerization of tetraethoxysilane (TEOS) was carried out using 1 in the gel phase. The silica obtained from the 1 + 1-butanol gel showed the tubular structure with ca. 100 nm outer diameter.