Chemistry, Volume 7, Issue 3 (June 2025) – 12 articles

Phlorotannins, bioactive compounds isolated from brown seaweeds, have garnered significant attention in recent years for their wide-ranging therapeutic properties, particularly their anti-inflammatory effects. Recent studies have identified phlorotannins as potent inhibitors of inflammatory pathways such as NF-κB, MAPK, JAK/STAT3, and NLRP3. Specifically, phlorotannins derived from seaweeds like Ecklonia cava, Ishige okamurae, and Sargassum horneri have been shown to inhibit the gene and protein expression of pro-inflammatory cytokines and other inflammatory mediators in both in vivo and in vitro conditions. Despite these promising findings, no commercial drugs derived from seaweed phlorotannins have yet been developed to treat inflammatory diseases, and reports of clinical trials remain rare, even in the context of functional food applications for chronic inflammatory conditions. To address this knowledge gap, the authors reviewed peer-reviewed research articles published in 2020 or later, focusing on the anti-inflammatory potential of phlorotannins. The insights provided in this review are expected to be valuable for industries such as functional food research groups and others involved in developing anti-inflammatory therapeutics. Full article

Direct Z-scheme heterojunctions are known for their unique carrier mobility mechanism, which significantly improves photocatalytic water splitting efficiency. In this study, we use first-principles simulations to determine the stability, electrical, and photocatalytic properties of a SnC/SnS₂ heterojunction. Analyses of the projected energy band and state density demonstrate that the SnC/SnS₂ heterojunction exhibits an indirect band gap of 0.80 eV and a type-II band alignment. Analysis of its work function shows that the SnC/SnS₂ heterojunction has a built-in electric field pointing from the SnC monolayer to the SnS₂ monolayer. The band edge position and the differential charge density indicate that the SnC/SnS₂ heterostructure exhibits a Z-scheme photocatalytic mechanism. Furthermore, the SnC/SnS₂ heterojunction exhibits excellent visible-light absorption and high solar-to-hydrogen efficiency of 32.8%. It is found that the band gap and light absorption of the heterojunction can be effectively tuned by biaxial strain. These results demonstrate that the fabricated SnC/SnS₂ heterojunction has significant photocatalysis potential. Full article

Zinc-halogen batteries are usually based on two-electron transfer reactions from X⁻ to X₂. However, the halogen is capable of being further oxidized to higher valence states, thereby achieving the higher capacity of zinc- halogen batteries. Here, a six-electron reaction based on I⁻/I⁺ and Br⁻/Br⁰ is activated successfully by introducing KI into the electrolyte. ZIF-8-derived porous carbon (ZPC), serving as the host of halogen, effectively suppresses polybromide/polyiodide shuttle owing to the chemisorption/physical adsorption. Additionally, the adsorption of I⁻ on the surface of the zinc anode effectively inhibits the growth of dendrites and the formation of by-products. Consequently, zinc-bromine batteries exhibit outstanding electrochemical performance, including a specific capacity of 345 mAh g⁻¹ at 1 A g⁻¹ and an excellent capacity retention of 80% after 3000 cycles at 2 A g⁻¹. This strategy provides a novel way for enhancing the electrochemical performance of zinc-halogen batteries. Full article

In this study, a statistical analysis of results reported in the literature was conducted through a 2ⁿ experimental design on the synthesis of bifunctional catalysts used in the production of lighter fuels, aiming for optimization while considering factors such as support (bentonite and vermiculite), acidity modifier (zirconium and cerium), metal (tungsten and molybdenum), metal content (5% and 10%), promoter (nickel and cobalt), and heteropolyacids (tungstophosphoric acid and molybdophosphoric acid), identifying their influence on textural properties and catalytic performance. Regarding the textural properties, vermiculite proved to be the most favorable support due to its high porosity. It was also established that the implemented metals impart positive characteristics to the catalysts due to their various properties; however, incorporating large amounts led to an adverse effect by clogging the pores. Catalytic performance was analyzed in isomerization and cracking reactions, which were enhanced by the use of cerium due to the presence of Brønsted acid sites and molybdenum for its stability. In this way, the statistical analysis conducted in this study was crucial for identifying the influence of key factors on the textural properties and catalytic performance of bifunctional catalysts. Using a 2ⁿ experimental design allowed for a systematic evaluation of variables reported in the literature, such as support, acidity modifiers, metals, metal content, promoters, and heteropolyacids. Full article

Hyperuricemia, induced by monosodium urate (MSU) crystals that accumulate in articular joints and periarticular soft tissues, can impair macrophages. Possible causes of macrophage injury include uric acid-induced oxidative stress or inflammation. This study examined the dried fruits of guava (DFG) as a complementary medicine with urate-lowering properties, utilizing THP-1 macrophages to determine if high uric acid-induced cellular damage could be mitigated through the reduction of oxidative stress and inflammation via treatment with a phytochemical extract. The active extract was prescreened using a xanthine oxidase (XO) inhibition assay coupled with fractionation and component analysis. The DFG extracts were used to identify, through an in vitro study of THP-1 cells. The results indicated that the DFG extracts with the highest total flavonoids (12.08 ± 0.81 mg/g DW) exhibited the XO inhibition activity. High-performance liquid chromatography–tandem mass spectrometry analysis showed that DFG extract contained 85.32% flavonoids, including quercetin and kaempferol derivatives. Furthermore, fractionation results of DFG extracts indicated a significant reduction in MSU-induced cytotoxicity in THP-1 cells obtained from the 75% ethanol-eluted fraction (Fr-75). Additionally, kaempferol, an active compound in Fr-75, effectively mitigated MSU-induced NF-κB and NLRP3 gene overexpression. These findings suggest that the prepared Fr-75 is a promising hyperuricemia therapeutic candidate. Full article

A ligand exchange reaction between [Ru₂(npc)₂(O₂CMe)₂] (1; npc = 1,8-naphthyridine-2-carboxylate) and trifluoroacetic acid yielded the diruthenium naphthyridine complex with two trifluoroacetate ligands, [Ru₂(npc)₂(O₂CCF₃)₂] (2), which was structurally characterized by electrospray ionization mass spectrometry, elemental analysis, infrared spectrum, and synchrotron single-crystal X-ray diffraction. The crystal structure of 2 adopts a paddlewheel-type structure in which two npc and two O₂CCF₃ ligands are coordinated in a cis-2:2 arrangement around the Ru₂ core. The temperature-dependent magnetic susceptibility measurements indicated that 2 has (i) an S = 1 spin state for the Ru₂⁴⁺ core and (ii) a large D value of 243 cm⁻¹; characteristic of paddlewheel-type Ru₂ complexes. The cyclic voltammetry measurements indicated that 2 exhibited one reversible oxidation wave (E_1/2 = 0.72 V vs. SCE) and two reduction waves (E_1/2 = −0.67 and −1.10 V vs. SCE); which were clearly positively shifted when compared with those of 1. Additionally, the absorption spectrum of 2 displayed intense absorption bands in the visible region; attributed to metal-to-ligand charge transfer from the Ru₂ core to the npc ligands; which were blue-shifted by approximately 70–100 nm when compared with those of 1. These distinct shifts in redox potentials and absorption bands originated from the strong electron-withdrawing effect of the O₂CCF₃ ligands in 2. Full article

A series of 4-aminoquinoline derivatives were prepared using a microwave-assisted method. The reactions were initially carried out on a small scale and subsequently scaled up using a sealed tube. Heating the reactions to 90–150 °C for 90–120 minutes obtained products with up to 95% yields. Structural analysis and characterization were achieved using FT-IR, ¹H- and ¹³C-NMR spectroscopy and HR-MS. Four compounds displayed low-to-moderate antibacterial activity, with 6-chlorocyclopentaquinolinamine (7b) exhibiting potent inhibition against MRSA (MIC = 0.125 mM) and 2-fluorocycloheptaquinolinamine (9d) showing activity against S. pyogenes (MIC = 0.25 mM). Structure–activity relationship (SAR) docking studies within the Penicillin Binding Protein (PBP2a) binding site (PDB: 4DK1) showed that compounds 7b and 5b (7-chlorophenylquinolinamine) bind through hydrophobic interactions (ALA601, ILE614), hydrogen bonding (GLN521), and halogen contacts (TYR519, THR399). Compound 7b demonstrated enhanced MRSA inhibition due to additional π-alkyl interactions and optimal docking parameters. Conversely, the bulky structure of 9d may explain its weaker activity as it likely hindered binding to the target site. This paper highlights the role of structural features in antibacterial efficacy and guides the future optimization of 4-aminoquinoline derivatives. Full article

N-Benzylhydroxylamine hydrochloride serves as a critical intermediate in organic synthesis, yet traditional synthesis methods often face significant safety risks and high production costs. In this work, we developed a continuous synthesis process for N-benzylhydroxylamine hydrochloride, achieving an overall yield of 75% under mild and safe reaction conditions. Additionally, the implementation of solvent recovery and the recycling of hydroxylamine hydrochloride reduced the production cost to approximately $10 per kilogram. These advancements underscore the economic and practical viability of this method for large-scale industrial applications. Full article

The influence of sodium 4-vinylbenzenesulfonate on the electrooxidation of phenols and naphthols was studied in dimethylformamide (DMF). The usually observed deactivation of phenol in non-aqueous environments was suppressed upon addition of sodium 4-vinylbenzenesulfonate, and signals of all studied compounds were highlighted due to the diminished background current. As in other cases, the latter is attributable to the solvent. The 4-vinylbenzenesulfonate salt underwent electroinitiated polymerization close to the electrode surface excluding all other compounds from it within the timescale of the measurements. The polymeric products were partially removed by dissolution; therefore, improved signal reproducibilities could be reached. The investigation was extended to pulsed voltammetric techniques widely used in analytical chemistry (differential pulse, normal pulse, square wave voltammetry). Among these techniques, differential pulse voltammetry showed the best performance. Therefore, during its use, the analytical usefulness of adding the unsaturated additive in optimal concentration was estimated in the case of some phenols and naphthols. Successful calibration for picric acid was attained in DMF. Full article

This study aims to evaluate the therapeutic potential of phloretin–chitosan nanoparticles (Ph-ChNPs), alone and in combination with the anticancer drug tamoxifen, in modulating breast cancer markers and improving in vivo treatment outcomes. Ph-ChNPs were prepared by ionic gelation in the presence of Tripolyphosphate (TPP) solution as a crosslinker agent. The nanoparticles were characterized using DLS, TEM, UV-VIS and FT-IR spectroscopy. In vitro cytotoxic assay of Ph-ChNPs on MCF-7 breast cancer cell lines revealed anticancer activity with an IC₅₀ value of 32.12 ± 1.63 µg/mL. In vivo studies were carried out on mice, treated with DMBA to induce breast cancer and followed the effect of the prepared nanoparticle, either alone or with combination with tamoxifen, on mice health. The biochemical parameters measured after treatment with Ph-ChNPs alone showed an improvement in lipid profile with decreased total cholesterol (TC) and Triglyceride (TG) levels and increased HDL-c levels. Ph-ChNPs significantly reduced IL-6 and cyclin D1 levels, with a slight increase in cyclin E2 levels. Antioxidant enzyme levels were improved, and oxidative stress markers were reduced. The combination treatment showed a synergistic effect in reducing inflammation and cell proliferation. DMBA-injected mice had substantially increased BRCA1 and BRCA2 gene expression. Ph-ChNP-treated mice showed well-organized mammary gland structures, while DMBA-injected mice displayed dense tumor cell aggregations. Ph-ChNPs and tamoxifen treatments improved histopathological variations, with the combination treatment showing significant apoptosis of tumor cells. This study demonstrates the significant potential of Ph-ChNPs combined with tamoxifen in breast cancer treatment. The combination therapy effectively reduces tumor growth, induces apoptosis and modulates critical breast cancer markers, offering a promising therapeutic strategy. Full article

Degenerate third-order nonlinear optical (NLO) responses of organic molecules have a wide range of applications in science and engineering because they relate to the intensity-dependent refractive index (IDRI) and nonlinear absorption (NLA), such as two-photon absorption (TPA). Among the many molecular systems, open-shell molecular species such as intermediate singlet diradicaloids have attracted considerable attention because of their enhanced response, predicted theoretically by Nakano et al. Experimental studies for proofing and evaluating the enhanced nonlinearities play an important role in the development of the field. This tutorial review provides the solid fundamentals of the NLO processes of open-shell molecular species even to those who are not familiar with the experimental works. Its scope ranges from the basics of NLO responses, definitions, and interrelations of the key parameters of the responses, such as hyperpolarizability and TPA cross-section, to the experimental techniques used to evaluate them. Including the recent achievements, the evolution of experimental works on the TPA properties of singlet diradicaloids is also reviewed according to families of molecular structures. Full article

Nitric oxide (NO) is an important messenger molecule in almost all organisms. The diverse biological activities of NO have initiated in-depth research on the development of exogenous NO donors. Light-controlled NO donor can transport NO to specific areas to treat various diseases; thus, light–triggered NO donors are rapidly becoming an important class of compounds for the design of novel potential drugs. This review highlights the recent development of organic small molecule-based light-triggered NO donors and focuses on visible/red/NIR light-mediated NO donors. It contains rational designs of NO donor, NO releasing mechanism and detection, as well as its biological applications. Finally, the advantages, drawbacks, and challenges of this strategy are discussed in view of practical applications. Full article