Fruit Vinegars as Natural and Bioactive Chitosan Solvents in the Production of Chitosan-Based Films.

Natural fruit vinegars, derived from various fruits, enhance culinary experience and offer potential health benefits due to their bioactive compounds. In this study, fruit vinegars (apple, blackcurrant, and cherry) were used as natural solvents for producing chitosan films, introducing an environmentally friendly approach. Fruit vinegars and chitosan-based solutions were examined for their antioxidant and antimicrobial properties.

Synthesis, Hemolytic Activity, and In Silico Studies of New Bile Acid Dimers Connected with a 1,2,3-Triazole Ring.

The synthesis of bile acid conjugates plays a significant role in pharmacology and organic chemistry. These complex compounds are widely studied due to their potential therapeutic applications (e.g.

Novel C3-Methylene-Bridged Indole Derivatives with and without Substituents at N1: The Influence of Substituents on Their Hemolytic, Cytoprotective, and Antimicrobial Activity.

Alkaloids are natural compounds useful as scaffolds for discovering new bioactive molecules. This study utilized alkaloid gramine to synthesize two groups of C3-substituted indole derivatives, which were either functionalized at N1 or not. The compounds were characterized by spectroscopic methods.

Synthesis and Hemolytic Activity of Bile Acid-Indole Bioconjugates Linked by Triazole.

New formyl and acetyl derivatives of bile acid propargyl esters and their bioconjugates with modified gramine molecules have been obtained using the click chemistry method to study their hemolytic potency. The structures of all compounds were confirmed by spectral (H- and C NMR and FT-IR) analysis and mass spectrometry (ESI-MS) as well as PM5 semiempirical methods. According to the results, the structural modification of formyl and acetyl bile acid derivatives, leading to the formation of new propargyl esters and indole bioconjugates, reduces their hemolytic activity.

Novel gramine-based bioconjugates obtained by click chemistry as cytoprotective compounds and potent antibacterial and antifungal agents.

A series of indole-1,4-disubstituted-1,2,3-triazole conjugates were synthesised by click chemistry. The haemolytic properties and cytoprotective activity of all the newly synthesised indole-triazole conjugates were tested . In addition, molecular docking was performed for the selected conjugates to determine their antibacterial and antifungal properties.

Tetramethylalloxazines as efficient singlet oxygen photosensitizers and potential redox-sensitive agents.

Tetramethylalloxazines (TMeAll) have been found to have a high quantum yield of singlet oxygen generation when used as photosensitizers. Their electronic structure and transition energies (S → S, S → T, T → T) were calculated using DFT and TD-DFT methods and compared to experimental absorption spectra. Generally, TMeAll display an energy diagram similar to other derivatives belonging to the alloxazine class of compounds, namely π,π* transitions are accompanied by closely located n,π* transitions.

Artificial Intelligence in Decrypting Cytoprotective Activity under Oxidative Stress from Molecular Structure.

Artificial intelligence (AI) is widely explored nowadays, and it gives opportunities to enhance classical approaches in QSAR studies. The aim of this study was to investigate the cytoprotective activity parameter under oxidative stress conditions for indole-based structures, with the ultimate goal of developing AI models capable of predicting cytoprotective activity and generating novel indole-based compounds. We propose a new AI system capable of suggesting new chemical structures based on some known cytoprotective activity.

Characteristics of Chitosan Films with the Bioactive Substances-Caffeine and Propolis.

Chitosan is a natural and biodegradable polymer with promising potential for biomedical applications. This study concerns the production of chitosan-based materials for future use in the medical industry. Bioactive substances-caffeine and ethanolic propolis extract (EEP)-were incorporated into a chitosan matrix to increase the bioactivity of the obtained films and improve their mechanical properties.

Click chemistry as a method for the synthesis of steroid bioconjugates of bile acids derivatives and sterols.

Six steroid conjugates of bile acids and sterol derivatives have been synthesized using the click chemistry method. The azide-alkyne Huisgen cycloaddition of the propionyl ester of lithocholic, deoxycholic and cholic acid with azide derivatives of cholesterol and cholestanol gave new bile acid-sterol conjugates linked with a 1,2,3-triazole ring. Previously, sterols were converted to bromoacetate substituted derivatives by reaction with bromoacetic acid bromide in anhydrous dichloromethane.

Synthesis, Structure and Biological Activity of Indole-Imidazole Complexes with ZnCl: Can Coordination Enhance the Functionality of Bioactive Ligands?

The ability of the indole-imidazole hybrid ligands to coordinate with the Zn(II) ion and the resulting structures of this new class of coordination compounds were analyzed in order to determine their structural properties and biological functionalities. For this purpose, six novel Zn(II) complexes, [Zn(InIm)Cl] (), [Zn(InMeIm)Cl] (), [Zn(IniPrIm)Cl] (), [Zn(InEtMeIm)Cl] (), [Zn(InPhIm)Cl] () and [Zn(InBzIm)Cl] () (where InIm is 3-((1H-imidazol-1-yl)methyl)-1H-indole), were synthesized by the reactions of ZnCl and the corresponding ligand in a 1:2 molar ratio in methanol solvent at an ambient temperature. The structural and spectral characterization of these complexes was performed using NMR, FT-IR and ESI-MS spectrometry and elemental analysis, and the crystal structures of - were determined using single-crystal X-ray diffraction.

5-Deazaalloxazine as photosensitizer of singlet oxygen and potential redox-sensitive agent.

Flavins are a unique class of compounds that combine the features of singlet oxygen generators and redox-dependent fluorophores. From a broad family of flavin derivatives, deazaalloxazines are significantly underdeveloped from the point of view of photophysical properties. Herein, we report photophysics of 5-deazaalloxazine (1a) in water, acetonitrile, and some other solvents.

New C8-substituted caffeine derivatives as promising antioxidants and cytoprotective agents in human erythrocytes.

New structurally diverse groups of C8-substituted caffeine derivatives were synthesized and evaluated for their chemical and biological properties. Mass spectrometry, FT-IR, and NMR characterizations of these derivatives were performed. The cytotoxic activity of the derivatives was estimated in vitro using human red blood cells (RBC) and in silico pharmacokinetic studies.

Indole Derivatives Bearing Imidazole, Benzothiazole-2-Thione or Benzoxazole-2-Thione Moieties-Synthesis, Structure and Evaluation of Their Cytoprotective, Antioxidant, Antibacterial and Fungicidal Activities.

In the search for new bioactive compounds, a methodology based on combining two molecules with biological properties into a new hybrid molecule was used to design and synthesize of a series of ten indole derivatives bearing imidazole, benzothiazole-2-thione, or benzoxazole-2-thione moieties at the C-3 position. The compounds were spectroscopically characterized and tested for their antioxidant, antibacterial, and fungicidal activities. The crystal structures were determined for five of them.

Biological Activity and Chemical Composition of Propolis from Various Regions of Poland.

Propolis is one of the bee products, with multiple biological properties used in numerous applications. The research objective was to determine the chemical composition and biological properties (antibacterial, antifungal, antiviral, antioxidant, and cytoprotective activity) of propolis extracts collected from various regions of Poland. The results indicated that the total content of phenols (116.

Photophysical properties of alloxazine derivatives with extended aromaticity - Potential redox-sensitive fluorescent probe.

The spectral and photophysical properties of two four-ring alloxazine derivatives, naphtho[2,3-g]pteridine-2,4(1H,3H)-dione (1a) and 1,3-dimethylnaphtho[2,3-g]pteridine-2,4(1H,3H)-dione, (1b) were studied. The propensity of 1a for excited-state proton transfer reactions in the presence of acetic acid as a catalyst was also studied, showing no signature of the reaction occurring. In addition, quenching of 1a fluorescence by acetic acid was investigated.

Multifunctionality of Nanosized Calcium Apatite Dual-Doped with Li/Eu Ions Related to Cell Culture Studies and Cytotoxicity Evaluation In Vitro.

Li/Eu dual-doped calcium apatite analogues were fabricated using a microwave stimulated hydrothermal technique. XRPD, FT-IR, micro-Raman spectroscopy, TEM and SAED measurements indicated that obtained apatites are single-phased, crystallize with a hexagonal structure, have similar morphology and nanometric size as well as show red luminescence. Lithium effectively modifies the local symmetry of optical active sites and, thus, affects the emission efficiency.

Synthesis, antioxidant and cytoprotective activity evaluation of C-3 substituted indole derivatives.

A series of fifteen indole derivatives substituted at the C-3 position were synthesized and characterized. The antioxidant activity of all derivatives was investigated by three in vitro antioxidant assays, and the derivative with pyrrolidinedithiocarbamate moiety was the most active as a radical scavenger and Fe-Fe reducer. It can be stated that possible hydrogen and electron transfer mechanism is suggested for the quenching of the free radical.

Ligand-Sensitised LaF :Eu and SrF :Eu Nanoparticles and in Vitro Haemocompatiblity Studies.

Luminescent Ln -doped nanoparticles (NPs) functionalised with the desired organic ligand molecules for haemocompatibility studies were obtained in a one-pot synthesis. Chelated aromatic organic ligands such as isophthalic acid, terephthalic acid, ibuprofen, aspirin, 1,2,4,5-benzenetetracarboxylic acid, 2,6-pyridine dicarboxylic acid and adenosine were applied for surface functionalisation. The modification of the nanoparticles is based on the donor-acceptor character of the ligand-nanoparticle system, which is an alternative to covalent functionalisation by peptide bonding as presented in our recent report.

Effect of the Solvent on Propolis Phenolic Profile and its Antifungal, Antioxidant, and In Vitro Cytoprotective Activity in Human Erythrocytes Under Oxidative Stress.

Propolis is a natural bee product with various beneficial biological effects. The health-promoting properties of propolis depend on its chemical composition, particularly the presence of phenolic compounds. The aim of this study was to evaluate the relationship between extraction solvent (acetone 100%, ethanol 70% and 96%) and the antifungal, antioxidant, and cytoprotective activity of the extracts obtained from propolis.

Surface Modification of Luminescent Ln Fluoride Core-Shell Nanoparticles with Acetylsalicylic acid (Aspirin): Synthesis, Spectroscopic and in Vitro Hemocompatibility Studies.

Luminescent lanthanide fluoride core-shell (LaF :Tb ,Ce @SiO -NH ) nanoparticles, with acetylsalicylic acid (aspirin) coated on the surface have been obtained. The synthesized products, which combine the potential located in the silica shell with the luminescent activity of the core, were characterized in detail with the use of luminescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) methods. The in vitro effects of the modified luminescent nanoparticles on human red blood cell (RBC) membrane permeability, RBC shape, and sedimentation rate were investigated to assess the hemocompatibility of the obtained compounds.

Preparation and preliminary evaluation of bio-nanocomposites based on hydroxyapatites with antibacterial properties against anaerobic bacteria.

Hexagonal nanocrystalline powders of the non-doped Ca(PO)(OH) as well as activated with Ag and Eu ions were synthesized by using different wet chemistry methods. Moreover, the obtained hydroxyapatite was loaded with Ag, as well as nitroimidazole antimicrobials: metronidazole and tinidazole. The structural properties of the products were analyzed by X-ray diffraction (XRD), scanning (SEM) and transmission (TEM) electron microscopy as well as infrared (IR) and Raman spectroscopy.

Non-cytotoxic hydroxyl-functionalized exfoliated boron nitride nanoflakes impair the immunological function of insect haemocytes in vivo.

To induce the water solubility of hexagonal boron nitride (h-BN), we exfoliated and functionalized bulk h-BN with hydroxyl groups (h-BN-OH-n). Short-term studies showed that h-BN-OH-n induced low cytotoxicity in different models: insect haemocytes (in vivo), human erythrocytes and mouse fibroblasts (in vitro). We also demonstrated that Alexa Fluor 647-h-BN-OH-n administered topically to the insects passed through the cuticle barrier and was phagocytosed by haemocytes.

Antioxidant and cytotoxic activity of new di- and polyamine caffeine analogues.

A series of new di- and polyamine-caffeine analogues were synthesised and characterised by NMR, FT-IR, and MS spectroscopic methods. To access the stability of the investigated caffeine analogues, molecular dynamic simulations were performed in NAMD 2.9 assuming CHARMM36 force field.