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Chitosan (CH) exhibits low antimicrobial activity. This study addresses this issue by modifying the chitosan with a sulfonamide derivative, 3-(4-(N,N-dimethylsulfonyl)phenyl)acrylic acid. The structure of the sulfonamide-chitosan derivative (DMS-CH) was confirmed using Fourier transform infrared spectroscopy and Nuclear magnetic resonance. The results of scanning electron microscopy, thermal gravimetric analysis, and X-ray diffraction indicated that the morphology changed to a porous nature, the thermal stability decreased, and the crystallinity increased in the DMS-CH derivative compared to chitosan, respectively. The degree of substitution was calculated from the elemental analysis data and was found to be moderate (42%). The modified chitosan exhibited enhanced antimicrobial properties at low concentrations, with a minimum inhibitory concentration (MIC) of 50 µg/mL observed for B. subtilis and P. aeruginosa , and a value of 25 µg/mL for S. aureus , E. coli , and C. albicans . In the case of native chitosan, the MIC values doubled or more, with 50 µg/mL recorded for E. coli and C. albicans and 100 μg/mL recorded for B. subtilis , S. aureus , and P. aeruginosa . Furthermore, toxicological examinations conducted on MCF-7 (breast adenocarcinoma) cell lines demonstrated that DMS-CH exhibited greater toxicity (IC50 = 225.47 μg/mL) than pure CH, while still maintaining significant safety limits against normal lung fibroblasts (WI-38). Collectively, these results suggest the potential use of the newly modified chitosan in biomedical applications.

This study aims to synthesize and evaluate the corrosion inhibition properties of three newly prepared organic compounds based on benzo[h]quinoline hydrazone derivatives. The compounds structure were characterised using FTIR, 1H-NMR, 13C-NMR and Mass spectroscopy. Electrochemical methods, including Potentiodynamic Polarization (PP), Electrochemical Frequency Modulation (EFM), and Electrochemical Impedance Spectroscopy (EIS) were employed to evaluate the compounds as corrosion inhibitors in HCl (1.0 M) for carbon steel (CS). Additionally, surface examination techniques such as scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to investigate the surface morphology and elemental composition of the CS before and after exposure to the synthesized compounds. The electrochemical measurements showed that compound VII achieved corrosion inhibition efficiency. SEM and EDX analysis further confirmed the creation of a passive film on the CS surface. These findings demonstrated the potential of benzo[h]quinoline hydrazone derivatives as effective organic corrosion inhibitors for CS in aggressive solution.

The emergence of multidrug-resistant microbes and the propagation of cancer cells are global health issues. The unique properties of chitosan and its derivatives make it an important candidate for therapeutic applications. Herein, a new thiadiazole derivative, 4-((5-(butylthio)-1,3,4-thiadiazol-2-yl) amino)-4-oxo butanoic acid (BuTD-COOH) was synthesized and used to modify the chitosan through amide linkages, forming a new thiadiazole chitosan derivative (BuTD-CH). The formation of thiadiazole and the chitosan derivative was confirmed by FT-IR, 1 H/ 13 C-NMR, GC–MS, TGA, Elemental analysis, and XPS. The BuTD-CH showed a high antimicrobial effect against human pathogens Escherichia coli , Pseudomonas aeruginosa , Bacillus subtilis , Staphylococcus aureus , and Candida albicans with low MIC values of 25–50 μg ml −1 compared to unmodified chitosan. The in-vitro cytotoxicity of BuTD-CH was evaluated against two cancer cell lines (MCF-7 and HepG2) and one normal cell (HFB4) using the MTT method. The newly synthesized derivatives showed high efficacy against cancerous cells and targeted them at low concentrations (IC 50 was 178.9 ± 9.1 and 147.8 ± 10.5 μg ml −1 for MCF-7 and HepG2, respectively) compared with normal HFB4 cells (IC 50 was 335.7 ± 11.4 μg ml −1 ). Thus, low concentrations of newly synthesized BuTD-CH could be safely used as an antimicrobial and pharmacological agent for inhibiting the growth of human pathogenic microbes and hepatocellular and adenocarcinoma therapy.

Novel azo dyes containing a hydrazide-hydrazone moiety linked to the benzothiazole nucleus are synthesized effectively in this study. The primary purpose of the study was to identify the best dyeing parameters, such as shade, temperature, pH, and time, in order to better understand the behaviour of dispersed dyes during polyester dyeing. To achieve excellent colour strength in value (K/S = 26), the ideal dyeing conditions for disperse dye 4 were 30 min, pH of 8, and 110 °C at shade 3%. While the ideal dyeing conditions for disperse dyes dye 10 and dye 11 were 30 min, pH of 2, and 130 °C at a shade of 3%. Depending on the coupler moieties, the coloured polyester samples ranged in hue from beige to dark brown. Furthermore, the impact of substituent’s was examined in relation to colour strength (K/S) measures and colourimetric coordinates (CIEL*a*b*) of dyed polyester fabrics. The synthesized dispersed dyes are good options for giving polyester textiles a variety of stable hues and very good colour strength as well as exceptional fastness to light, washing, and crocking.

A novel sulfamoylphenyl-dihydro-thiadiazole derivative (compound 14 ) has been designed and synthesized as a dual inhibitor targeting EGFR and human carbonic anhydrases (hCA_IX and hCA_XII). Computational studies, including density functional theory (DFT), molecular docking, and molecular dynamics simulations, confirmed its stability, favorable binding interactions, and reactivity profiles. Compound 14 showed potent inhibition of EGFR (IC₅₀ = 10.12 ± 0.29 nM), hCA_IX and hCA_XII (IC₅₀ = 79 ± 1.2 nM and 58 ± 0.9 nM, respectively). Cytotoxicity assays demonstrated selective activity against cancer cells, with IC₅₀ values of 16.13 µM in MDA-MB-231 and 22.57 µM in MCF-7 cells, compared to 148.32 µM in non-cancerous Vero cells. Compared to acetazolamide, compound 14 exhibited improved selectivity for cancer cells. Apoptosis studies revealed significant cell death in MDA-MB-231 cells, with early and late apoptosis rates of 22.50% and 58.27%, respectively, alongside a marked G1-phase cell cycle arrest (49.10% in treated cells vs. 44.98% in controls). In silico toxicological evaluations indicated a favorable safety profile, with low irritancy and acceptable rat oral LD₅₀ (15.81 mg/kg) and carcinogenic potency (TD₅₀ = 36.95). Compound 14 ’s potent dual inhibition and selective cytotoxicity make it a promising candidate for further optimization and in vivo studies.

Cancer poses a significant therapeutic challenge due to its multifactorial origin and resistance to conventional remedies. Our previous efforts identified N -sulfonylpiperidine derivatives as potent VEGFR-2 inhibitors (Compound A). Herein, we report a rational design, synthesis, and biological assessment of a new series of analogs to enhance anticancer efficacy through scaffold optimization and multi-target engagement. Strategic modifications on A included group repositioning, diversifying the terminal aromatic substituents, and linker replacement. Among the synthesized derivatives, compound 16 exhibited promising cytotoxic activities across three cell lines, in comparison with the lead compound A and vinblastine. Preliminary mechanistic studies confirmed that 16 induced G0/G1 cell cycle arrest and promoted early apoptosis in MCF-7 cells. Enzyme inhibition assays further revealed that our derivative acts as a dual inhibitor of VEGFR-2 and EGFR versus moderate activity against topoisomerase II. Molecular docking studies supported these findings by showing favorable binding orientations and interactions within the VEGFR-2 active site. The binding pattern of 16 showed key hydrogen bonding and hydrophobic contacts that enhance ligand affinity. Altogether, this work highlights the impact of these modifications and introduces 16 as a promising lead to develop multitargeted anticancer therapeutics that inhibit tyrosine kinases and DNA-processing enzymes.

Herein, two new polymers designated as Cs-EATT and Cs-BATT have been synthesized via linking the chitosan with the synthesized 1,3,4-thiadiazole compounds. They were characterized using 1 H, 13 C-NMR, FT-IR, TGA, Elemental analysis, Mass spectrum, and UV–vis spectrophotometer. The synthesized polymers exhibit high activity to control the growth of pathogenic bacteria ( S. aureus , B. subtilis , E. coli, and P. aeruginosa ), and unicellular fungi ( C. albicans ). The MIC values were in the range of 25–100 µg mL –1 for Cs-EATT and 25–200 µg mL –1 for Cs-BATT with varied clear zones. The new polymers were mixed with three film-forming agents: polyvinyl alcohol, hydroxyethyl cellulose, and carboxymethyl cellulose to form six film dressings designated as E1, E2, and E3 for Cs-EATT, and B1, B2, and B3 for Cs-BATT, respectively. The evaluation of film dressings showed that the formed films had transparency, uniformity, homogeneity, elasticity, and non-irritation pH values for skin within the normal range. The maximum percentages of Cs-E/B-ATT content were recorded for film dressings E2 and B2, with values of 92.5% and 94.9%, respectively. Also, the release percentages varied according to film dressing formulation, with values in the ranges of 83.88–93.2% for Cs-EATT and (87.7–97.35%) for Cs-EATT after 9 h.

In this study, a new modified chitosan conjugate (Chito-TZ) was developed via amide coupling between the acid chloride derivative of the methylthio-thidiazole compound and the free primary amino groups of chitosan. The product was characterized using several instrumental investigations, including Fourier-transform infrared spectroscopy (FT-IR), 1H-Nuclear magnetic resonance, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). XRD indicated that the crystalline pattern of chitosan was interrupted after chemical modification with the thiadiazole derivative. Broido’s model was used to determine the thermal activation energy Ea, and the results showed that the Ea for the first decomposition region of Chito-TZ is 24.70 KJ mol−1 lower than that required for chitosan (95.57 KJ mol−1), indicating the accelerating effect of the thiadiazole derivative on the thermal decomposition of Chito-TZ. The modified chitosan showed better antibacterial and antifungal activities than the non-modified chitosan; except for seed germination, chitosan was better. The Chito-TZ showed a low MIC value (25–50 µg mL−1) compared to Chito (50–100 µg mL−1). Moreover, the maximum inhibition percentages for plant-pathogenic fungi, Aspergillus niger, Fusarium oxysporum, and Fusarium solani, were attained at a concentration of 300 µg mL−1 with values of 35.4 ± 0.9–39.4 ± 1.7% for Chito and 45.2 ± 1.6–52.1 ± 1.3% for Chito-TZ. The highest germination percentages (%) of broad bean, shoot and root length and weight, and seed vigor index were obtained after Chito treatment with a concentration of 200 µg mL−1 compared to Chito-TZ.

Recently, chitosan derivatives, as eco-sustainable and renewable products, have been recorded to be highly effective toward cosmetics with potent biological activity. The main core of this research is to develop an organic hair conditioner (OHC) based on two chitosan-thiadiazole conjugates, chitosan-(ethylthio‑thiadiazole) (CH-ETD) and chitosan-(benzylthio‑thiadiazole) (CH-BTD), with natural fragrances. A series of nine OHC formulae were prepared (CH1-CH3 for chitosan based OHC, E1-E3 for CH-ETD based OHC, and B1-B3 for CH-BTD based OHC) and characterized based on their visual examination, pH, thermal stability, dirt dispersion, moisturizing time , percentage of solid content, hair irritation, rinsing, combing, and the luster. The results showed that the pH values of all OHC formulae were 4.2–4.7 which is considered acceptable to avoid skin irritation. A distinctive film surrounds each individual hair shaft in the CH-ETD and CH-BTD treated groups when compared to control hair without the application of hair conditioner under a scanning electron microscope SEM with a magnification power of 100 μm. Additionally, every single hair shaft is clearly covered, and the control group exhibited noticeable hair issues that were not observed in the treated groups, which showed no signs of tangling. Due to the end-use performance properties of the formulated hair conditioner products, it can be concluded that the formulas of (CH, E2, and B2) were the best efficacy; hair easier to style, detangle the hair, retain moisture, not be very thick, not cause irritation or inflammation, minimize frizz, and create a protective barrier on the hair. These findings collectively validate the potential of CH-ETD and CH-BTD based formulations coupled with natural perfumery as a transformative approach to hair care, aligning with consumer preferences for both efficacy and environmental sustainability. Furthermore, in this work, docking studies have been conducted to provide theoretical proof about the significant roles of chitosan and keratin in hair growth and cosmetic applications (skin). Graphical Abstract

This study presents the synthesis and characterization of novel lanthanide complexes, specifically La (III) and Gd (III), designed as flame-retardant additives for paint formulations. The complexes were synthesized and thoroughly characterized using different spectroscopic techniques, complemented by density functional theory computational calculation insights. The resulting La (III) and Gd (III) complexes were then incorporated into paint formulations, and the physical properties of the modified coatings were systematically evaluated. Ignitability and the minimum oxygen percentage required for sustained combustion were quantified according to standardized procedures. The modified coatings demonstrated enhanced mechanical and ignition properties in comparison to blank samples. The limiting oxygen index (LOI) values were notably higher, underscoring the efficacy of the lanthanide complexes as flame retardant additives. La complex led to an ignition time of 850 s and an LOI of 40, while Gd complex resulted in the same ignition time of 850 s and LOI of 50 compared to the uncoated sample of 550 s and an LOI of 16. The mechanical properties of the painted samples, engineered with the inclusion of these prepared metal complexes, exhibited a significant improvement. This comprehensive investigation provides valuable insights into the potential application of lanthanide complexes as effective flame-retardant additives in coatings, offering a promising avenue for enhancing the safety and performance of various materials.