Syntheses and aggregation properties of new squalene receptors bearing open chain ligands

New squalene receptors bearing open-chain polyether ligands (SQ-diEG, SQ-triEG, SQ-tetraEG) were synthesised. The stoichiometries and association constants (K-a) for the interactions between these squalene receptors and representative alkaline earth metal ions (Mg2+, Ca2+, and Ba2+) were determined in solution. Fluorescence spectral studies revealed that the squalene receptors self-associate with critical vesicle concentrations at 25 degrees C of 2.2 x 10(-5) M for SQ-diEG, 2.3 x 10(-5) M for SQ-triEG, and 2.5 x 10(-5) M for SQ-tetraEG. The self-assembly behaviour was probed using laser diffraction particle size-based analyses and scanning electron microscopy. A decrease in the SQ-tetraEG vesicle size was readily induced by the addition of alkaline earth metal ions, confirmed by cryogenic transmission electron microscopy.

Automated summary

New squalene receptors with open-chain polyether ligands were synthesized and found to interact with alkaline earth metal ions. Self-assembly behavior of the receptors at 25 degrees C was studied using fluorescence spectral analysis and microscopy, showing vesicle size changes induced by the metal ions. Cryogenic transmission electron microscopy confirmed the decrease in vesicle size of SQ-tetraEG upon addition of the metal ions.