Hierarchical Preferences of Hydroxylated Oxanorbornane-Based Achiral Amphiphiles

Abstract

Achiral amphiphiles with hydroxylated oxanorbornane headgroups showed specific morphological characteristics and hierarchical preferences depending upon the nature of lipophilic units. Detailed scanning electron microscopic (SEM) studies showed that twisted ribbonlike aggregates are characteristic of monoalkoxyaryl lipids with hydrocarbon chain length in the range C10-C13; these systems also had a preference toward lamellar arrangement. Asymmetric packing of these lipids is a unique occurrence and shows that the presence of molecular chirality is not an absolute requirement for curvature effects in their supramolecular assemblies. Aryl units in these systems were found to be important for the observed morphological preferences, which became evident from comparative studies involving simple long chain esters without this moiety. Single-crystal X-ray diffraction analysis of one of the lipids from the latter group gave finer details of strong and weak secondary interactions, which operate during their assembly process. Introduction of more than one alkyl chain on the aromatic ring caused a notable shift in the packing propensity toward columnar arrangement. Most of these cone-shaped molecules were found to give doughnut-shaped aggregates from acetone solution through the intermediary of fibrous structures, which was confirmed through SEM, transmission electron microscopic, and atomic force microscopic studies.

Smart Materials for Environmental Remediation Based on Two-Component Gels: Room-Temperature-Phase-Selective Gelation for the Removal of Organic Pollutants Including Nitrobenzene/O-Dichlorobenzene, and Dye Molecules from the Wastewater

“…The XRD patterns of G1-A16 nitrobenzene xerogel showed d spacing values of 1.25, 0.64, 0.43, and 0.32 nm (Fig. 5e) in a ratio of 1:1/2:1/3:1/4, indicating the lamellar arrangements [46, 47]. Similarly, the XRD patterns of G1-A16 /water xerogel and G1-A16 powder suggested the lamellar arrangements.…”

Exploring the Physical Properties of Lipid Membranes with Polyhydroxy Oxanorbornane Head Group Using NBD-Conjugated and DPH Fluorescent Probes

“…Additionally, the aggregation behavior of amphiphiles based on the polyhydroxy-ONB headgroup with the different lipophilic units was investigated. 14 We observed that the polyhydroxy-ONB-based amphiphiles form structures such as twisted ribbons and doughnut-shaped assemblies depending upon the nature of lipophilic units. Furthermore, the polyhydroxy-ONB headgroup was modified to achieve dimensionally controlled nanostructures.…”

“…This investigation highlighted the similarities in material properties between these polyhydroxy ONB-based amphiphiles and glycolipids. Additionally, the aggregation behavior of amphiphiles based on the polyhydroxy-ONB headgroup with the different lipophilic units was investigated . We observed that the polyhydroxy-ONB-based amphiphiles form structures such as twisted ribbons and doughnut-shaped assemblies depending upon the nature of lipophilic units.…”

1‐Hydroxymethyl‐7‐oxabicyclo[2.2.1]hept‐2‐ene skeleton in enantiopure form through enzymatic kinetic resolution

“…[48][49][50][51][52][53][54][55][56][57][58][59] Several strategies have been attempted to overcome this, such as the use of chiral or sterically demanding acyl donors, 56,60 optimization of solvation conditions, 61 or through sequential resolutions. [62][63][64][65] Since access to this skeleton in enantio-pure form would allow us to make comparative assessment of properties, we set out to investigate the lipase catalysed enantioselective acylation of 6 as shown in Scheme 1. Our group has been working on new functional mimics of glycolipids based on hydroxylated oxanorbornane head group, for use in drug delivery.…”

“…Our group has been working on new functional mimics of glycolipids based on hydroxylated oxanorbornane head group, for use in drug delivery. [62][63][64][65] Since access to this skeleton in enantio-pure form would allow us to make comparative assessment of properties, we set out to investigate the lipase catalysed enantioselective acylation of 6 as shown in Scheme 1.…”