Background: Burn wound repair is driven by oxidative balance and keratinocyte regeneration. Polyphenol-rich botanicals are considered promising due to combined antioxidant and pro-regenerative properties. This study compares four ethnopharmacologically relevant species—Boswellia serrata (BS), Sambucus nigra (SN), Ocimum basilicum (OB), and Galium verum (GV)—to determine how their polyphenolic class profiles relate to in vitro regenerative activity. Methods: Ethanolic (E—99.5%) and hydroalcoholic (H—70%) extracts were profiled by LC–MS, total polyphenol content (TPC), and DPPH assays. Biological effects were assessed in HaCaT keratinocytes using Alamar Blue (24/48 h) and scratch wound closure (24 h), and results were correlated with chemical profiles. Results: The H extract of OB (OB-H) and of GV (GV-H) had the highest TPC (62.6 and 63.9 mg GAE/g) and lowest DPPH IC50 (18.7 and 17.1 μg/mL), aligning with the strongest biological responses—HaCaT viability up to 169.1% and wound closure up to 414%. SN extracts, dominated by rutin, promoted moderate migration with preserved viability, whereas BS produced modest viability gains. Conclusions: Polyphenolic composition—particularly the dominance of phenolic acids—correlates strongly with in vitro regenerative responses in HaCaT keratinocytes. O. basilicum and G. verum hydroalcoholic extracts displayed the most favorable profiles.

Thiophene derivatives are particularly attractive for application in drug development for their versatile pharmacological properties. We synthesized a series of four compounds with thiophene carboxamide as a scaffold. The structures were established based on HR-MS and 1D- and 2D-NMR. The purity of the compounds was established to be greater than 92% by thin-layer chromatography and NMR. The cytotoxic effects of the newly synthesized compounds were evaluated against the normal HaCaT cell line and A375, HT-29, and MCF-7 cancer cell lines. The cytotoxic assessment revealed that two compounds exhibit a significant cytotoxic effect on all cancer cell lines. To investigate their potential underlying mechanisms of action, several tests were performed: immunofluorescence imaging, caspase-3/7 assay, mitochondrial membrane potential (JC-1) assay, and 2′,7′–dichlorofluorescein diacetate (DCFDA) assay. MB-D2 proved to be the most cytotoxic and effective in terms of caspase 3/7 activation, mitochondrial depolarization and decrease in ROS production; these effects did not occur in normal HaCaT cells, revealing that MB-D2 has a high selectivity against A375 cancer cells.

This study evaluated the potential of silibinin linoleate (SL), a natural derivative of silibinin, as an antioxidant to improve the thermal stability of sunflower oil (SF). SL was synthesized through green technology by enzymatic esterification, using mild reaction conditions. SL was added to high-oleic SF samples at three concentrations (200, 400, and 600 ppm), and the oils were subjected to heating at 180 °C for 4 and 8 h. Oxidative stability, fatty acid composition, and nutritional indices were analyzed. The results showed that 600 ppm SL provided the strongest antioxidant effect, significantly reducing oxidation parameters after 8 h of heating, in addition to the following values: peroxide value (PV) 14.22 ± 0.31 meq O2/kg, p-anisidine value (p-AV) 22.85 ± 0.34, inhibition of oxidation (IO) 56.41 ± 0.31%, and total oxidation value (TOTOX) 51.30 ± 0.39. FTIR spectroscopy confirmed that SL effectively protected the triglyceride structure and limited the formation of oxidation by-products. SL demonstrated a protective effect against thermal oxidation in sunflower oil, with its efficacy being clearly dose-dependent. At 600 ppm, SL showed comparable or superior activity to BHT. However, this effect was specific to the highest tested concentration and does not indicate superiority across all concentrations. These findings suggest that SL has potential as a natural antioxidant for improving oil stability, but further studies are needed to validate SL as a practical and scalable alternative to synthetic antioxidants in the food industry.

We investigate two unusual phenomena in self-assembly of anisotropic molecules from isotropic (Iso) melt: a heat-capacity (Cp) maximum and spontaneous formation of the recently discovered chiral liquid (Iso*). Based on experiments on new nonchiral monomers, dimers, and polymers, we construct a statistical theory that shows why many complex meso-structures form in two stages: continuous equilibrium growth of nano-clusters in melt through strong interactions, causing the Cp-maximum, followed by establishment of positional long-range order (LRO) through a weak first-order transition. We also show why many achiral compounds additionally form an intermediate chiral Iso* liquid through what we find is a second-order transition. We propose that the first process is equivalent to "supramolecular polymerization" in solutions, where the lack of intercluster interaction rules out LRO. Furthermore, we argue that separation into a broad and a sharp transition is universal in condensed matter where strong interactions by themselves cannot lead to LRO, either because the clusters are 1D or due to strong frustration. Clusters must first grow to critical size when, at Tc, the combined weak interactions reach ∼kBTc, prompting LRO formation. A situation similar to that in soft self-assembly is seen in spin ordering in magnetic crystals, but only near 0 K.

A polysiloxane with tris-alkoxy-ended rod-like mesogenic side groups forms an unusually low-symmetry antiferrochiral liquid crystal, space group P1̅, consisting of distorted left- and right-handed double-helices containing alternating splay and twist sections. The unit cell contains two double-helical columns. On faster cooling, a closely related metastable orthorhombic structure is formed, symmetry Fddd, with 8 double helices per cell.

Among the intriguing bicontinuous self-assembled structures, the gyroid cubic is the most ubiquitous. It is found in block and star polymers, surfactants with or without solvent, in thermotropic liquid crystals with end- or side-chains, and in biosystems providing structural color and modelling cell mitosis. It contains two interpenetrating networks of opposite chirality and is thus achiral if, as usual, the content of the two nets is the same. However, we now find that this is not the case for strongly chiral compounds. While achiral molecules follow the opposite twists of nets 1 and 2, molecules with a chiral center in their rod-like core fail to follow the 70° twist between junctions in net 2 and instead wind against it by −110° to still match the junction orientation. The metastable chiral gyroid is a high-entropy high-heat-capacity mesophase. The homochirality of its nets makes the CD signal of the thienofluorenone compounds close to that in the stable I 23 phase with 3 isochiral nets.

The recently discovered orthorhombic liquid crystal (LC) phase of symmetry Fddd is proving to be widespread. In this work, a chiral hydroxybutyrate linkage is inserted into the molecular core of hexacatenar rodlike compounds, containing a thienylfluorenone fluorophore. In addition to more usual tools, the methods used include grazing-incidence X-ray scattering, modulated differential scanning calorimetry (DSC), flash DSC with rates up to 6000 K/s, and chiro-optical spectroscopies using Mueller matrix method, plus conformational mapping. Although pure R and S enantiomers form only a strongly chiral hexagonal columnar LC phase (Colh*), the racemic mixture forms a highly ordered Fddd phase with 4 right- and 4 left-handed twisted ribbon-like columns traversing its large unit cell. In that structure, the two enantiomers locally deracemize and self-sort into the columns of their preferred chirality. The twisted ribbons in Fddd, with a 7.54 nm pitch, consist of stacked rafts, each containing ∼2 side-by-side molecules, the successive rafts rotated by 17°. In contrast, an analogous achiral compound forms only the columnar phase. The multiple methods used gave a comprehensive picture and helped in-depth understanding not only of the Fddd phase but also of the "parachiral" Colh* in pure enantiomers with irregular helicity, whose chirality is compared to the magnetization of a paramagnet in a field. Unusual short-range ordering effects are also described. An explanation of these phenomena is proposed based on conformational analysis. Surprisingly, the isotropic–columnar transition is extremely fast, completing within ∼20 ms. A clear effect of phase on UV–vis absorption and emission is observed.

A metallomesogen based on an Zn(II) coordination complex was employed as precursor to obtain a complex matrix nanoplatform for the fabrication of a high-performance electrochemical hybrid sensor. Three representative paste electrodes, which differ by the weight ratio between Zn(II) metallomesogen and carbon nanotubes (CNT), i.e., PE_01, PE_02 and PE_03, were obtained by mixing the materials in different amounts. The composition with the largest amount of CNT with respect to Zn complex, i.e., PE_03, gives the best electrochemical signal for uric acid detection by cyclic voltammetry in an alkaline medium. The amphiphilic structure of the Zn(II) coordination complex likely induces a regular separation between the metal centers favoring the redox system through their reduction, followed by stripping, and is characterized by enhanced electrocatalytic activity towards uric acid oxidation. The comparative detection of uric acid between the PE_03 paste electrode and the commercial zinc electrode demonstrated the superiority of the former, and its great potential for the development of advanced electrochemical detection of uric acid. Advanced electrochemical techniques, such as differential-pulsed voltammetry (DPV) and square-wave voltammetry (SWV), allowed for the highly sensitive detection of uric acid in aqueous alkaline solutions. In addition, a good and fast amperometric signal for uric acid detection was achieved by multiple-pulsed amperometry, which was validated by urine analysis.

On the >1 µm scale the morphology of semicrystalline plastics like polyethylene or Nylon features spherulites, “shish-kebabs”, cylinddrites and other crystalline aggregates which strongly affect mechanical and other material properties. Current imaging techniques give only a 2D picture of these objects. Here we show how they can be visualized in 3D using fluorescent labels and confocal microscopy. As a result, we see spherulites in 3D, both in neat polymers and their nanocomposites, and observe how unevenly nanoparticles and other additives are distributed in the material. Images of i-polypropylene and biodegradable poly(lactic acid) reveal previously unsuspected morphologies such as “vases” and “goblets”, nonspherical “spherulites” and, unexpectedly, “shish-kebabs” grown from quiescent melt. Also surprisingly, in nanocomposite sheets spherulite nucleation is seen to be copied from one surface to another, mediated by crystallization-induced pressure drop and local melt-flow. These first results reveal unfamiliar modes of self-assembly in familiar plastics and open fresh perspectives on polymer microstructure.

In the present study, new magnetic nanocomposites were successfully prepared by combustion method, characterized by X-ray diffraction, Fourier transform infrared spectroscopy, magnetic measurements, N2 adsorption–desorption thermal analysis, and scanning electron microscopy, and tested as adsorbents for the removal of anionic dyes (Acid Yellow 42 and Acid Red 213) from aqueous solutions. The influence of process variables solution pH, adsorbent dose, initial dye concentration and temperature on the adsorption was evaluated. The best kinetic model that fitted with experimental data was a pseudo-second order model, and the equilibrium data were correlated by Langmuir isotherm model for the investigated dyes. Maximum removal efficiencies of 98.54% and 97.58% was obtained for Acid Yellow 42 and Acid Red 213, respectively, indicating the superior adsorption capacity of the new synthesized magnetic nanocomposites. The thermodynamic parameters indicated the spontaneous and endothermic nature of the adsorption process.

The similarity between 2,6-Bis(2-hydroxyarylidene)cyclohexanones and 2′-hydroxychalcones in generating respectively styrylflavylium and flavylium cations was explored.

The distribution of additives and nanoparticles in a semicrystalline polymer is largely dependent on the complex hierarchical polymer morphology and the kinetics of its development. Here we show by in-situ fluorescence microscopy (FM), coupled with polarized optical and scanning electron microscopy, that a substantial fraction of the additive (Nile Red, NR) and even NR-labelled silica nanoparticles (NP) and quantum dots (QD) was pushed ahead of the growing spherulites during melt-crystallization. For the 35 and 200 nm NPs this was unexpected because their diffusion coefficient based on Stokes-Einstein equation should have been 2-3 orders of magnitude slower than the rate at which spherulites were growing. Another surprising finding was that much of the initially rejected NR and some QDs subsequently re-entered the spherulites through back-diffusion, posing the question why they were then rejected in the first place. The excessive initial rejection of NR and QDs and the unexpectedly rapid migration of NPs are both explained by the additive preferentially filling and being carried along by the polymer depletion zone in the melt ahead of the growing spherulite, and the high negative pressure in these zones. The effectiveness of FM in detecting minute cracks and cavities is also demonstrated. The results also show that the most severe clustering of additives occurs where spherulites did not nucleate, a problem preventable by the addition of nucleating agent.

The network of chemical reactions of 2, 6-bis(5-bromo-2-hydroxybenzylidene)cyclohexanone (BHBC) when subjected to light and different pH values has been investigated. The pH dependent species involved in the chemical network have been identified and characterized by NMR and UV-VIS spectroscopy. Direct pH jumps were carried out by adding a strong acid to equilibrated solutions of trans -chalcone (Ct) forming the flavylium cation which was stable only under extremely acidic conditions (pH < 0.5). The single crystal X-ray study and NMR analysis has confirmed the structure of the new flavylium cation. In the case of a reverse pH jump, the Ct species interconverted instantaneously into deprotonated trans -chalcone (Ct^2−) around pH 12. A new colorless compound 3, 11-dibromo-7, 8-dihydro-6 H -chromeno[3, 2- d ]xanthene (B–B) isolated from the equilibrated solution of trans -chalcone species in methanol after long periods of time (100 h) under dark conditions has been isolated and fully characterized by NMR and X-ray diffraction. The rate of the reaction increased when the solution of trans -chalcone was exposed to light and the total conversion of Ct into the spiropyran-like compound (B–B) was achieved in about 30 minutes. The B–B form was stable under neutral and basic conditions, while at low pH values it converts into a cationic AH^+ form.

A series of homologous Schiff bases N,N′-bis[(4-decyloxy-salicylideneamino)-n-propyl]-piperazine] (ZOPPH2), and N,N′-bis[(4-dodecyloxy-benzylideneamino)-n-propyl]-piperazine (DBPP)(1), based on 1,4-bis(3-amino-propyl)-piperazine (APPZ), were designed and synthesized, with APPZ serving as the piperazine core, bilaterally flanked by extended alkyl chain-containing antennae. Driven by the pursuit of metallomesogenic materials bearing liquid crystalline state properties, chemical reactivity toward divalent metals Co(II) and Cu(II), in alcoholic or tetrahydrofuran/dimethylsulfoxide media, led to compounds [{Co(ZOPP)}(ClO4)]2.(CH3OH).2(CH3)2SO(2) and [Cu(APPZ)Cl]Cl(3). All materials were characterized by elemental analysis, spectroscopic techniques (UV–Visible, FT-IR, NMR where appropriate), molar conductivity, and X-ray crystallography. Physicochemical characterization emphasizes the a) importance of N,O-containing Schiff anchors in metal ion binding, b) significance of the phenolic moiety, on the flanks of the Schiff ligands, in promoting either metal ion complexation or dissociation of the Schiff base at the azomethine moiety junction, thereby altering metal ion chemical reactivity, and c) observed oxidation of Co(II) to Co(III) upon mononuclear complex formation. Hybrid DFT calculations on DBPP and ZOPPH2 suggest increased reactivity of the Schiff CHN moiety, in the absence of the phenolic moiety, and concurrent metal ion presence, thereby lending credence to the notion of metal-assisted rupture of the specific bond in DBPP and the emergence of specific metal-ligand product(s). Collectively, the data denote the significance of structural features of piperazine-core Schiff antennae ligands in a) promoting chemical reactivity toward transition metals, b) defining metal-ligand complexation and lattice architecture, and c) parameterizing such chemical reactivity into synthetic advances toward new materials with well-defined solid-state architecture, lattice and physicochemical properties.

Wedge-shaped molecules, such as dendrons, are among the most important building blocks for directed supramolecular self-assembly. Here we present a new approach aimed at widening the range and complexity of potential mesophases by introducing double-tapered mesogens. Two series of compounds are presented, both alkali metal salts (Li, Na, Cs) of 3,4,5-tris-alkoxybenzoic acid with a second tapered tris-alkoxyaryl group attached at the end of an alkoxy chain. The double-tapered compounds all display an unusual hexagonal columnar phase consisting of one ionic and three non-ionic columns per unit cell. The cation size has an unexpectedly drastic effect on unit cell size. Unlike most columnar phases, the current phases show unusually high dimensional stability on heating, and high stiffness in spite of being 80-85 % aliphatic, attributed to their molecular topology. The described approach may lead to co-assemblies of multifunctional materials, for example, parallel p- and n-semiconducting nanowires or parallel ionic and electronic conductors.

The photochromic compound 2,6-bis(2-hydroxybenzilidene)cyclohexanone (PC) has been dissolved in some selected liquid amphiphiles: dibutyl, tributyl, bis-2-ethylhexyl, tris-2-ethylhexyl phosphate and bis-2-ethylhexyl amine. The aim was to explore its photophysical properties when embedded in the novel chemical environment provided by the amphiphilic solvents. UV-Vis spectra revealed different features depending on the solvent thus highlighting specific solvent-solute interactions and different chemical environments. All the alkylphosphate-based systems were found to be unstable; slow (days) changes in the absorption features due to the slow change in populations of the various species present in solution. Interestingly, the dissolution of PC into bis-2-ethylhexyl amine leads to stable solutions most probably due to the basic character of the solvent stabilising as major specie chalcone forms. Fluorescence spectra suggested the equilibrium between two species with different absorption and fluorescence properties.

As in supramolecular chemistry, complexity could also be achieved through a bottom-up approach. Anthocyanins and related compounds such as the compound (E)-6-(dimethylamino)-4-(4-(dimethylamino)-2-hydroxybenzylidene)-1,2,3,4-tetrahydroxanthylium chloride (1), here reported, exhibit this type of complexity. The thermodynamics and kinetics of the complex multistate of species of compound 1 were studied by conventional and stopped-flow UV-visible spectrophotometry as well as by NMR. The system follows the same multistate of species of anthocyanins, except for the presence at moderately basic pH values of a species possessing a spiro carbon. The introduction of two dimethylamino substituents in positions 4' and 7, modulates deeply the thermodynamic and kinetics of the system. A beautiful pH-dependent palette of colors is obtained, including a blue flavylium cation at unusually high pH values. The protonation of the dimethylamino substituents is the key aspect for explaining the details of the spiro opening kinetics. The system was fully characterized by representing the mole fraction distribution and the relative energy level diagram of all multistate species as a function of pH.

New thermotropic ionic liquid crystalline (ILCs) salts of nicotinic acid with different counterions have been synthesized and characterized by spectral (AAS, IR, UV-Vis and H-1 NMR) methods and molar conductivity. Their thermal behaviour was investigated by thermal analysis. The liquid crystalline properties were evidenced by polarized optical microscopy (POM). The mesomorphic behaviour of ILCs is influenced by the nature of anionic species and/or presence of metal ion. The synthesized compounds exhibit fluorescence at room temperature in solution.

Two new mononuclear complexes [MnL](ClO4) (1) and [CoL](NO3)center dot 2CH(3)OH (2) containing N,N'-bis[(2-hydroxybenzilideneamino)propyl]-piperazine (H2L) have been synthesized and structurally characterized. Complex 1 crystallizes in the monoclinic space group P2(1)/c, with cell dimensions a = 11.5180(6), b = 15.7885(8), c = 13.2207(7) angstrom,beta = 90.162(4)degrees, complex 2 in the trigonal space group, with cell dimensions a = 17.4723(3), b = 17.4723(3), c = 47.655(1) angstrom, gamma = 120 degrees. X-ray structure determinations of 1 and 2 revealed that both compounds consist of mononuclear complex cations containing trivalent metal centers, Mn-III or Co-III. The metal ions are coordinated in a distorted octahedral fashion by the N-4 donor set of the ligand in basal and the two phenoxo oxygen atoms in apical positions. Spectral properties are consistent with the crystallographic results. The electrochemical properties of the complexes have been investigated by cyclic voltammetry. The reversible behavior of the Mn system was slightly affected by the changes in the coordination environment during the overall redox process, while the Co-III/Co-III system exhibited an irreversible behavior.