Chiral amplification of disodium cromoglycate chromonics induced by a codeine derivative

Abstract

Chromonic liquid crystals (CLC) are lyotropic phases formed by discotic mesogens in water. Simple chiral dopants such as amino acids have been reported to turn chromonic liquid crystals into their cholesteric counterparts. Here we report a chirality amplification effect in the nematic phase of a 9 wt% disodium cromoglycate (DSCG) lyotropic liquid crystal (LLC) upon doping with a water-soluble codeine derivative. The transition on cooling the isotropic to the nematic phase showed the presence of homochiral spindle-shaped droplets (tactoids). NMR DOSY experiments on a triple gradient probe revealed a small degree of diffusion anisotropy for the alkaloid embedded in the liquid crystal structure. These results in combination with XRD, CD and POM experiments agree with a supramolecular aggregation model based on simple columnar stacks.

Chiral Amplification by L‐Cysteine‐Capped Gold Nanoparticles in Lyotropic Chromonic Liquid Crystals

“…Overall, the current data clearly show that chiral amplification by metal NPs with a chiral ligand shell consisting of biologically relevant amino acids, and chiral surfaces as a result thereof, can be detected with LCLCs, similar to other chiral drug or biological relevant molecules . This chiral amplification, suggested earlier for cholesterol and chiral binaphthyl ligand‐capped Au NPs in thermotropic N‐LCs, is here several orders of magnitude more intense.…”

Thermotropic Liquid Crystal-Assisted Chemical and Biological Sensors

“…This is a critical requirement for the applications mentioned above to mitigate the occurrence of false optical signal. Berride et al reported that addition of small chiral organic molecules—such as amino acids—to achiral disodium chromo glycate (DSCG) phases induces a chiral phase through the formation of tactoids at the interface between isotropic and nematic phases [ 39 ]. This interesting effect on the LC director configuration can be used in enantio-selective detection or chirality discrimination.…”

Cromoglycate mesogen forms isodesmic assemblies promoted by peptides and induces aggregation of a range of proteins

“…Additives such as ions and water-soluble organic molecules can have an impact on the transition concentration of 5 0 DSCG from isotropic solutions to nematic liquid crystal phases. 13,17,23,[30][31][32] The isodesmic assembly formation is predicted to be a step towards the formation of the LC phase as these isodesmic assemblies align in solution. 13,14,27 However, the extensive studies and characterization of these isodesmic assemblies are lacking.…”