A molecular anion pump.

Pumping ions against a concentration gradient through protein-based transporters is a cornerstone of numerous biological processes. Mimicking this function by using artificial receptors remains a daunting challenge, mainly because of the difficulties in balancing between the requirement for high binding affinities and precise and on-demand ion capture and release properties. We report a trimeric hydrazone photoswitch-based receptor that converts light energy into work by actively transporting chloride anion against a gradient through a dichloromethane liquid membrane, functioning as a molecular pump.

A small-molecule self-assembled nanodrug for combination therapy of photothermal-differentiation-chemotherapy of breast cancer stem cells.

The combination therapy with different treatment modalities has been widely applied in the clinical applications of cancer treatment. However, it stills a considerable challenge to achieve co-delivery of different drugs because of distinct drug encapsulation mechanisms, low drug loading, and high excipient-related toxicity. Cancer stem cells (CSCs) are closely related to tumor metastasis and recurrence due to high chemoresistance.

A biomimetic nanodrug self-assembled from small molecules for enhanced ferroptosis therapy.

Ferroptosis drugs often induce oxidative damage or block antioxidant defense due to the key mechanism of ferroptosis involved in cancer treatment, regulating the intracellular redox balance. However, these ferroptosis drugs are unstable during systemic circulation, and they lack tumor-targeting capability. Herein, we developed a stimuli-responsive and cell membrane-coated nanodrug for the simultaneous delivery of two ferroptosis drugs, an iron-chelating drug as a ROS inducer and sorafenib as an antioxidase inhibitor.

A Heteromeric Carboxylic Acid Based Single-Crystalline Crosslinked Organic Framework.

The development of large pore single-crystalline covalently linked organic frameworks is critical in revealing the detailed structure-property relationship with substrates. One emergent approach is to photo-crosslink hydrogen-bonded molecular crystals. Introducing complementary hydrogen-bonded carboxylic acid building blocks is promising to construct large pore networks, but these molecules often form interpenetrated networks or non-porous solids.

Controlled Polymerization of Norbornene Cycloparaphenylenes Expands Carbon Nanomaterials Design Space.

Carbon-based materials-such as graphene nanoribbons, fullerenes, and carbon nanotubes-elicit significant excitement due to their wide-ranging properties and many possible applications. However, the lack of methods for precise synthesis, functionalization, and assembly of complex carbon materials has hindered efforts to define structure-property relationships and develop new carbon materials with unique properties. To overcome this challenge, we employed a combination of bottom-up organic synthesis and controlled polymer synthesis.

Visualizing intracellular particles and precise control of drug release using an emissive hydrazone photochrome.

The spatiotemporal control over the structure of nanoparticles while monitoring their localization in tumor cells can improve the precision of controlled drug release, thus enhancing the efficiency of drug delivery. Here, we report on a photochromic nanoparticle system (), assembled from fluorescent bistable hydrazone photoswitch-modified amphiphilic copolymers. The intrinsic emission of the hydrazone switch allows for the visualization of particle uptake, as well as their intracellular distribution.

Planarization-Induced Activation Wavelength Red-Shift and Thermal Half-Life Acceleration in Hydrazone Photoswitches.

The optimization and modulation of the properties of photochromic compounds, such as their activation wavelengths and thermal relaxation half-lives (), are essential for their adaptation in various applications. In this work, we studied the effect of co-planarization of the rotary fragment of two photochromic hydrazones with the core of the molecule on their switching properties. The and isomers of both compounds exhibit red-shifted absorption bands relative to their twisted versions, allowing for their photoswitching using longer wavelengths of light.

Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone.

In this work we apply a combination of steady state and time resolved luminescence and absorption spectroscopies to investigate the excited-state dynamics of a recently developed molecular photoswitch, belonging to the hydrazone family. The outstanding properties of this molecule, involving fluorescence toggling, bistability, high isomerization quantum yield and non-negligible two-photon absorption cross section, make it very promising for numerous applications. Here we show that the light induced isomerization occurs on a fast <1 ps timescale in both toluene and acetonitrile, while the excited state lifetime of the -form depends on solvent polarity, suggesting a partial charge transfer nature of its low lying excited state.

White-light emission from a structurally simple hydrazone.

Two hydrazones featuring a unique excitation wavelength-dependent dual fluorescence emission have been developed. The mixing extent of the two emission bands can be modulated by tuning the excitation wavelength, resulting in multicolor and even white light emission from structurally simple hydrazones.

Structure Property Analysis of the Solution and Solid-State Properties of Bistable Photochromic Hydrazones.

The development of new photochromic compounds and the optimization of their photophysical and switching properties are prerequisites for accessing new functions and opportunities that are not possible with currently available systems. To this end we recently developed a new bistable hydrazone switch that undergoes efficient photoswitching and emission ON/OFF toggling in both solution and solid-state. Here, we present a systematic structure-property analysis using a family of hydrazones and show how their properties, including activation wavelengths, photostationary states (PSSs), photoisomerization quantum yields, thermal half-lives (τ), and solution/solid-state fluorescence characteristics vary as a function of electron donating (EDG) and/or withdrawing (EWG) substituents.

Building Strain with Large Macrocycles and Using It To Tune the Thermal Half-Lives of Hydrazone Photochromes.

Strain has been used as a tool to modulate the reactivity (e.g., mechanochemistry) and thermal isomerization kinetics of photochromic compounds.

Eight new cycloartane triterpenoids from Beesia calthifolia with hepatoprotective effects against D-galactosamine induced L02 cell damage.

Fourteen 20,24-epoxy-cycloartane triterpenoids, including eight new ones (1-8), were isolated from 95% ethanol extract of the rhizomes of Beesia calthifolia. Their structures were determined by spectroscopic and chemical methods, especially 2D NMR and HRMS techniques. Among them, four new compounds (1-4) possess carbonyl groups at C-16, which were rarely found in cycloartane triterpenoids from this genus.

Five new cycloartane triterpenoids from Beesia calthifolia.

Phytochemical study on rhizomes of Beesia calthifolia resulted in the isolation of five new (1-5) and three known (6-8) cycloartane triterpenoids possessing a hemiketal or ketal group at C-24 from the EtOAc fraction of 95% ethanol extract. Their structures were determined by spectroscopic and chemical methods, especially HRMS and 2D NMR techniques. Compounds 3 and 4 showed potential hepatoprotective activities against D-galactosamine induced human hepatic L02 cell damage.