Synthesis and Liquid Crystalline Properties of Mono‐, Di‐ and Tri‐O‐alkyl Pentaerythritol Derivatives Bearing Tri‐, Di‐ or Monogalactosyl Heads: The Effects of Curvature of Molecular Packing on Mesophase Formation

Abstract

Self-organisation and self-assembly are critical to the stability of synthetic and biological membranes. Of particular importance is consideration of the packing arrangements of the various molecular species. Both phospho- and glycolipids can pack in ways in which curvature can be introduced into self-organised or self-assembled systems. For instance, it is known that the degree of curvature can affect the structures of any condensed phases that are formed. In this article we report on a systematic study in which we have varied the shapes of glycolipids and examined the condensed phases that they form. In doing so, we have also unified the shape dependency of lyotropic liquid crystals with those of thermotropic liquid crystals. In order to undertake this systematic study a range of different pentaerythritol derivatives was synthesized, which covers combinations of one to three alkyl chains of different lengths (6,7,9,10,11,12,14,16 carbon atoms) and three to one galactosyl heads. Mono- and di-O-galactosyl derivatives were prepared directly by glycosylation of the corresponding alcohols using 2,3,4,6-tetra-O-benzoyl or acetyl-alpha-D-galactopyranosyl trichloroacetimidate or bromide as the donors; the tri-O-galactosyl derivatives were synthesized from O-alkyl-O-benzyl di-O-galactosyl pentaerythritol intermediates, followed by de-O-benzylation and glycosylation steps. All of the fully deprotected products were obtained by standard methods, and their self-organising and self-assembling properties examined.

Supramolecular organization of dendritic supermolecules into liquid crystalline mesophases

“…silylated spacers [16]) or at the periphery (e.g. carbohydrate groups [17], fluorinated chains [18]), induction of stable mesophases (enantiotropic phases) is nevertheless observed. This core was considered as a potential source for the fabrication of non-symmetrical segmented dendrimers (Fig.…”

A Family of Hydrogels Based on Ureido‐Linked Aminopolyol‐Derived Amphiphiles and Bolaamphiphiles: Synthesis, Gelation under Thermal and Sonochemical Stimuli, and Mesomorphic Characterization

“…As expected, the driving force for the formation of the liquid-crystal phase is the generation of intermolecular hydrogenbonding between hydroxy groups and the segregation of hydrophobic chains and sugar head groups. [30] Table 2 summarizes the type of phase formed for each compound and the temperature at which it is formed. Ureas derived from aminopolyol 3 showed in general little or no activity.…”

Design and Synthesis of Lipidic Organoalkoxysilanes for the Self‐Assembly of Liposomal Nanohybrid Cerasomes with Controlled Drug Release Properties

“…Materials : Pentaerythritol, glycerol, dibutyltin dilaurate, 3‐isocyanatopropyltriethoxysilane (IPTS), 1‐bromohexadecane, succinic anhydride, triethylamine, tetrabutylammonium bromide, aminopropyltriethoxysilane, N , N ‐dimethyl formamide (DMF), N ‐(3‐dimethylaminopropyl)‐ N ′‐ethylcarbodiimide hydrochloride (EDC ⋅ HCl, 99 %), and 4‐dimethylaminopyridine (DMAP) were commercially available and were utilized as received. N ‐[ N ‐(3‐triethoxysilyl)propylsuccinamoyl]dihexadecylamine (lipid A),32 4‐(dihexadecylamino)‐4‐oxobutanoic acid ( 1 ),32 and 3‐(hexadecyloxy)‐2,2‐bis(hexadecyloxymethyl)propan‐1‐ol ( 4 )40 were synthesized according to the literature procedures. 1 H NMR and mass spectra of the synthetic compounds are shown in the Supporting Information.…”