Water-soluble platinum and palladium porphyrins with peripheral ethyl phosphonic acid substituents: synthesis, aggregation in solution, and photocatalytic properties.

Water-soluble porphyrins have garnered significant attention due to their broad range of applications in biomedicine, catalysis, and material chemistry. In this work, water-soluble platinum(II) and palladium(II) complexes with porphyrins bearing ethyl phosphonate substituents, namely, Pt/Pd 10-(ethoxyhydroxyphosphoryl)-5,15-di(-carboxyphenyl)porphyrins (M3m, M = Pt(II), Pd(II)) and Pt/Pd 5,10-bis(ethoxyhydroxyphosphoryl)-10,20-diarylporphyrins (M1d-M3d; aryl = -tolyl (1), mesityl (2), -carboxyphenyl (3)), were synthesized by alkaline hydrolysis of the corresponding diethyl phosphonates M6m and M4d-M6d. NMR, UV-vis, and fluorescence spectroscopy revealed that the mono-phosphonates M3m tend to form aggregates in aqueous media, while the bis-phosphonates M3d exist predominantly as monomeric species across a wide range of concentrations (10-10 M), ionic strengths (0-0.

Preparation of Langmuir-Blodgett Films from Quinoxalines Exhibiting Aggregation-Induced Emission and Their Acidochromism.

The development of aggregation-induced emission (AIE)-exhibiting compounds heavily relies on our evolving comprehension of their behavior at interfaces, an understanding that still remains notably limited. In this study, we explored the preparation of two-dimensional (2D) sensing films from 2,3-diphenylquinoxaline-based diazapolyoxa- and polyazamacrocycles displaying AIE the Langmuir-Blodgett (LB) technique. This systematic investigation highlights the key role of the heteroatom-containing tether of 2,3-diphenylquinoxalines in the successful fabrication of Langmuir layers at the air-water interface and the transfer of AIE-emitting supramolecular aggregates onto solid supports.

Quinoxaline-based azamacrocycles: synthesis, AIE behavior and acidochromism.

The development of luminescent molecular materials has advanced rapidly in recent decades, primarily driven by the synthesis of novel emissive compounds and a deeper understanding of excited-state mechanisms. Herein, we report a streamlined synthetic approach to light-emitting diazapolyoxa- and polyazamacrocycles NCOQ and NCQ ( = 3-10; = 2, 3; = 2-5), incorporating a 2,3-diphenylquinoxaline residue (DPQ). This synthetic strategy based on macrocyclization through Pd-catalyzed amination reaction yields the target macrocycles in good or high yields (46-92%), enabling precise control over their structural parameters.

Implications of high homocysteine levels in migraine pain: An experimental study of the excitability of peripheral meningeal afferents in rats with hyperhomocysteinemia.

Objectives: Investigation of chronic homocysteine action on the excitability and N-methyl-D-aspartate (NMDA) sensitivity of the peripheral trigeminovascular system of rats.

Background: Migraine is a neurological disease that affects 15%-20% of the general population. Epidemiological observations show that an increase of the sulfur-containing amino acid homocysteine in plasma-called hyperhomocysteinemia-is associated with a high risk of migraine, especially migraine with aura.

Dual-Responsive and Reusable Optical Sensors Based on 2,3-Diaminoquinoxalines for Acidity Measurements in Low-pH Aqueous Solutions.

This work is focused on the age-old challenge of developing optical sensors for acidity measurements in low-pH aqueous solutions (pH < 5). We prepared halochromic (3-aminopropyl)amino-substituted quinoxalines and possessing different hydrophilic-lipophilic balance (HLB) and investigated them as molecular components of pH sensors. Embedding the hydrophilic quinoxaline into the agarose matrix by sol-gel process allows for fabrication of pH responsive polymers and paper test strips.

On the relationship between the properties of planar structures of non-ionic surfactants and their vesicular analogues - Niosomes.

In recent years, the study of niosomes as nanocarriers alternative to liposomes has received increasing attention. In contrast to well-studied liposome membranes, many aspects of the behavior of analogous niosome bilayers have not been studied. This paper considers one of these aspects related to the communication between the physicochemical properties of planar and vesicular objects.

Synthesis and Self-Assembly of β-Octa[(4-Diethoxyphosphoryl)phenyl]porphyrins.

The β-substituted porphyrinoids commonly used to form functional assembled systems in nature yet are still scarcely used in material chemistry probably due to the laborious synthesis of these compounds. In this work, β-octa[(4-diethoxyphosphoryl)phenyl]porphyrin () and its metal (Zn(II), Cd(II), Cu(II), and Ni(II)) complexes were prepared in good yields. These highly soluble chromophores were characterized in solution using spectroscopic (NMR, UV-vis, fluorescence), electrochemical, and spectroelectrochemical methods.

Testing the Role of Glutamate NMDA Receptors in Peripheral Trigeminal Nociception Implicated in Migraine Pain.

The pro-nociceptive role of glutamate in the CNS in migraine pathophysiology is well established. Glutamate, released from trigeminal afferents, activates second order nociceptive neurons in the brainstem. However, the function of peripheral glutamate receptors in the trigeminovascular system suggested as the origin site for migraine pain, is less known.

Alcohol metabolite acetic acid activates BK channels in a pH-dependent manner and decreases calcium oscillations and exocytosis of secretory granules in rat pituitary GH3 cells.

Acetaldehyde and acetic acid/acetate, the active metabolites of alcohol (ethanol, EtOH), generate actions of their own ranging from behavioral, physiological, to pathological/cancerogenic effects. EtOH and acetaldehyde have been studied to some depth, whereas the effects of acetic acid have been less well explored. In this study, we investigated the effect of acetic acid on big conductance calcium-activated potassium (BK) channels present in GH3 rat pituitary tumor cells in more detail.

Protective Effects of Hydrogen Sulfide Against the ATP-Induced Meningeal Nociception.

We previously showed that extracellular ATP and hydrogen sulfide (HS), a recently discovered gasotransmitter, are both triggering the nociceptive firing in trigeminal nociceptors implicated in migraine pain. ATP contributes to meningeal nociception by activating the P2X3 subunit-containing receptors whereas HS operates mainly TRP receptors. However, HS was also proposed as a neuroprotective and anti-nociceptive agent.

Interfacial self-assembly of functional bilayer templates comprising porphyrin arrays and graphene oxide.

Fabricating of solid-supported hybrid nanostructures remains a challenging problem because it is difficult to control all interfacial interactions influencing the structure and stability of these systems. The most widely used approach to solving this problem is a bottom-up assembly on the surface templates such as self-assembled monolayers (SAMs). Herein we suggest an alternative approach to tailoring solid surfaces by a formation of an interlayer anchoring the nanostructured film to the solid substrate.

A metal-responsive interdigitated bilayer for selective quantification of mercury(ii) traces by surface plasmon resonance.

Reusable surface plasmon resonance chips allowing the quantitative and selective detection of mercury(ii) ions in water at the 0.01 nM level are reported. The surface-modified gold sensor consists of a rarefied self-assembled monolayer of octanethiol topped with a Langmuir-Blodgett monolayer of an amphiphilic and highly-specific chelator.

Colorimetric Hg2+ sensing in water: from molecules toward low-cost solid devices.

A new colorimetric molecular sensor allowing for cheap, fast, sensitive, and highly selective naked-eye detection of Hg(2+) in water is described. This molecule combines a 1,8-diaminoanthraquinone signaling subunit and phosphonic acid esters that confer the water solubility to the dye (R = H). A ready-to-use colorimetric solid sensor was obtained by incorporating an amphiphilic analog (R = OC(12)H(25)) exhibiting similar binding properties and optical responses in an agarose film.