Photoswitchable Bis(amidopyrroles): Modulating Anion Transport Activity Independent of Binding Affinity

A photocaged, pH-sensitive anion transporter with AND logic dual-stimuli activation

A pH-switchable anion transporter 1 was photocaged with two photolabile groups to enhance spatiotemporal control over its chloride transport activity. Simultaneous application of light irradiation and acidic pH restores the activity of 1, while either stimulus alone results in no or very low activity. The double activation strategy described herein has potential to yield more selectively cytotoxic anionophores for future medical applications.

β-Carboline-based light and pH dual stimuli-responsive ion transporters induce cancer cell death

Light and pH dual-responsive ion transporters offer better applicability for cancer due to higher tunability and low cytotoxicity. Herein, we demonstrate the development of pH-responsive β-carboline-based ionophores and photocleavable-linker appended β-carboline-based proionophores to facilitate the controlled transport of Cl- across membranes, leading to apoptotic and autophagic cancer cell death.

Length dependent reversible off-on activation of photo-switchable relay anion transporters

A homologous series of azobenzene-derived photo-switchable ion relay transporters is reported. We reveal that both the length and geometry of the relay strongly affect transport rate, allowing the relative activity of the E and Z isomers to be reversed and hence the wavelengths of light used for on and off switching to be exchanged.

Switchable molecular tweezers: design and applications

Switchable molecular tweezers are a unique class of molecular switches that, like their macroscopic analogs, exhibit mechanical motion between an open and closed conformation in response to stimuli. Such systems constitute an essential component of artificial molecular machines. This review will present selected examples of switchable molecular tweezers and their potential applications. The first part will be devoted to chemically responsive tweezers, including stimuli such as pH, metal coordination, and anion binding. Then, redox-active and photochemical tweezers will be presented.

Molecular Machines For The Control Of Transmembrane Transport

Nature embeds some of its molecular machinery, including ion pumps, within lipid bilayer membranes. This has inspired chemists to attempt to develop synthetic analogues to exploit membrane confinement and transmembrane potential gradients, much like their biological cousins. In this perspective, we outline the various strategies by which molecular machines─molecular systems in which a nanomechanical motion is exploited for function─have been designed to be incorporated within lipid membranes and utilized to mediate transmembrane ion transport. We survey molecular machines spanning both switches and motors, those that act as mobile carriers or that are anchored within the membrane, mechanically interlocked molecules, and examples that are activated in response to external stimuli.