A Biocompatible Surfactant with Folded Hydrophilic Head Group:  Enhancing the Stability of Self-Inclusion Complexes of Ferrocenyl in a β-Cyclodextrin Unit by Bond Rigidity

Abstract

This work reports a new biocompatible surfactant structure, of which the hydrophilic head group is composed of a folded, stable self-inclusion complex of a ferrocenyl substituted beta-cyclodextrin (betaCD). While multiple intra- or intermolecular complexes can exist for this amphiphile, the molecule folds into a unique intramolecular complex with well-defined conformation, in which part of the aliphatic chain and the ferrocene group are both included in the annular cavity of betaCD. Study of different isosteric covalent linkages indicates that this folded structure is stable against displacement by the presence of other small guest molecules. Furthermore, in contrast to ferrocene-CD conjugates that are without the aliphatic chain, the presence of small guest molecules in solution does not influence at all the induced circular dichroism signal of this amphiphile, indicating a sterically congested, but stable, folded conformation of the inclusion complex. This new amphiphile is surface active and, more importantly, does not denature the membrane protein bacteriorhodopsin. Finally, because this surfactant forms self-assembled aggregates, this work introduces a folded structure into soft matters formed by amphiphiles in water.

Noncovalent Polymerization of Mesogens Crystallizes Lysozyme: Correlation between Nonamphiphilic Lyotropic Liquid Crystal Phase and Protein Crystal Formation

“…For this reason, we are studying the phase separation between these nonamphiphilic mesogens and surfactants, and exploring their ability to crystallize surfactant-protected membrane proteins. 64 …”

Ferrocene–β‐Cyclodextrin Conjugates: Synthesis, Supramolecular Behavior, and Use as Electrochemical Sensors

“…IR spectra were recorded by using a Mattson Genesis II FTIR instrument. 1 H, 13 C, selective 1D (gTOCSY) and 2D (gCOSY, gHMQC, gHMBC and gROESY) NMR spectra were recorded by using Bruker Avance DPX300 and Bruker Avance 500 Ultrashield spectrometers equipped with QNP 1 H/ 13 C/ 19 F/ 31 P and inverse TBI 1 H/ 31 P/BB probes, respectively. Standard Bruker software was used for acquisition and processing routines.…”

“…[10b,c] In addition to sensing purposes, Fc-CD conjugates have been used as artificial redox enzymes, [11] as mediators of enzyme-based biosensors, [12] and as redox-controllable amphiphilic molecules. [13] The b-CD has been grafted with a ferrocenedimethylsilyl group on one of the secondary hydroxyl groups of the wider rim after formation of a complex between the ferrocenylsilyl derivative reagent and the macrocycle. [14] To the best of our knowledge, only a Fc-bridged bisA C H T U N G T R E N N U N G (b-CD) has been reported.…”

“…Fc appended to β‐CD through an amide linkage has been used to build a rotaxane with an azobenzene‐containing thread bound to a Au electrode surface 10b,c. In addition to sensing purposes, Fc–CD conjugates have been used as artificial redox enzymes,11 as mediators of enzyme‐based biosensors,12 and as redox‐controllable amphiphilic molecules 13. The β‐CD has been grafted with a ferrocenedimethylsilyl group on one of the secondary hydroxyl groups of the wider rim after formation of a complex between the ferrocenylsilyl derivative reagent and the macrocycle 14.…”

Cu(II)-triggered release of paclitaxel from a supramolecular complex

“…2D ROSEY NMR, as a strong tool in realising the interactions within a distance of 5 Å (17,18), was used to study the mechanism of the 1/PTX binding. The 2D ROSEY NMR result of 1/PTX provides rich information about the precise position of PTX locating inside the molecule of 1.…”