Liquid crystalline glycosteroids and acyl steroid glycosides (ASG)
As part of our studies on glycolipidic liquid crystals, we have investigated some molecules comprising a steroid moiety. These systems can exhibit several types of structures depending on their polarity pattern based on the number of polar and non-polar moieties and their resulting molecular shape. Therefore, to aid describing such systems, we have proposed a specific classification based on this polarity pattern. Many compounds in this family are natural products, which possess important biological properties. Some of the compounds have bolaphilic structures, with both a steroid and a fatty alkyl chain attached to the carbohydrate moiety, such as either the β-galactoside BbGL-1 or the α-glucoside α-CAG that are found in the membranes of the pathogens Borrelia burgdorferi and Helicobacter pylori, respectively. In this account, after a brief introduction on liquid crystalline glycolipids, we focus on carbohydrate–steroid hybrids, summarising our previous work on glycosteroids prepared by the CMGL-synthon strategy, and reporting our preliminary results on the thermotropic behaviour of acyl steroid glycosides (ASG), namely cholesteryl 6-O-acyl-β-gluco- and -galacto-pyranosides.