Context: Okra, Abelmoschus esculentus (L.) (Malvaceae), is a medicinal plant widely used in Turkish traditional medicine for the treatment of various diseases such as ulcers and gastritis. Objective: In the present study, we evaluated the gastroprotective effect of okra against ethanol-induced acute gastric mucosal injury in animal models. Materials and methods: Wistar rats were treated with 500, 250 or 100 mg/kg okra; 20 mg/kg famotidine (Fam); and 75 mg/kg quercetin (Que). Following a 60 min period, all the rats were given 1 mL of ethanol (80%). One hour after the administration of ethanol, all groups were sacrificed. Results: At 5000 mg/kg, the extract produced (okra) no signs of toxicity in animals. Okra 500, 250, 100, Fam 20 and Que 75 inhibited ulcer formation by 81.0, 67.5, 67.0, 76.3 and 72.4%, respectively. Okra 500 significantly decreased edema, hemorrhage and inflammation scores compared with the ethanol group (p < 0.05). The oxidant levels decreased significantly in the all study groups compared within ethanol group (p < 0.001). Serum β-carotene and retinol levels significantly increased 40.2 and 45.4% in the okra 500 group. In okra 500, 250 and Fam 20 groups, apoptosis significantly decreased (p < 0.001), while okra 500, 250 and Fam 20 groups showed a higher percentage of cell proliferation compared with the ethanol group (p < 0.001). Discussion and conclusions: Our in vivo data indicate that okra has a gastroprotective effect against ethanol and could reduce the gastric ulcer as seen from biochemical and histopathological results. We suggest that okra could be a possible therapeutic antiulcer agent.

Here we determined the in vitro inhibitory effects of 5-(2-hydroxyethyl)-3,4-dimethylthiazolium iodide (1), 3-Benzyl-5-(2-hydroxyethyl)-4-methylthiazolium chloride (2) and thiamine (3) on human erythrocyte carbonic anhydrase I, II isozymes (hCA I and hCA II) and secreted isoenzyme CA VI. K_I values ranged from 0.38 to 2.27 µM for hCA I, 0.085 to 0.784 µM for hCA II and 0.062 to 0.593 µM for hCA VI, respectively. The compounds displayed relatively strong actions on hCA II, in the same range as the clinically used sulfonamidesethoxzolamide, zonisamide and acetazolamide.

The valorization of shrimp shell waste is crucial for promoting sustainability and a circular economy. This study aimed to extract chitin from the exoskeletal residues of deep-water rose shrimp (Parapenaeus longirostris) sourced from the Marmara Sea and synthesize low-molecular-weight chitosan (LMWC) via conventional, microwave-, and autoclave-assisted deacetylation pathways. The shell biomass was subjected to sequential demineralization (1 M HCl) and deproteinization (1 M NaOH), yielding 14.42% chitin. The extracted chitin was then converted to LMWC using the three methods, and the products were characterized using FT-IR spectroscopy, titration, viscometry, SEM, and TGA. The results demonstrated that the autoclave-assisted method achieved the highest degree of deacetylation (DD) at 95%, significantly outperforming the conventional method (81%) and the microwave-assisted method (67%). The autoclave-synthesized chitosan also exhibited the lowest viscosity (33 cP), confirming its low molecular weight. Morphological analysis showed that chitin exhibited a well-defined fibrous structure. After deacetylation, this structure transformed into a rough and porous surface morphology. Thermal analysis further demonstrated that the laboratory-synthesized chitosan exhibited higher thermal stability than the commercial chitosan sample. In conclusion, the autoclave-assisted method proved to be highly efficient for producing low-molecular-weight chitosan with a high degree of deacetylation. However, the conventional method remains the most practical option for scalable industrial production due to its simplicity and well-established infrastructure. Moreover, the laboratory-synthesized chitosan exhibited higher thermal stability, increased porosity, and a higher degree of deacetylation compared to commercially available chitosan, which may offer functional advantages in applications requiring enhanced reactivity, solubility, or thermal resistance. Overall, the findings provide valuable insights into selecting appropriate deacetylation strategies for producing low-molecular-weight chitosan with tailored properties, thereby bridging the gap between laboratory-scale synthesis and potential industrial applications.

Phenolic acids and flavonoids remain attractive redox-active scaffolds in medicinal chemistry, where they are widely used for early-stage prioritization and intrinsic reactivity ranking. However, direct comparisons under harmonized conditions remain scarce, limiting structure-based assessment. Here, a structurally diverse panel of hydroxybenzoic acids, hydroxycinnamic acids, flavonoids, a flavanone, and synthetic comparators was profiled using Folin–Ciocalteu response, ABTS radical cation scavenging, DPPH radical scavenging, and reducing power assays. The data reveal pronounced assay dependence alongside clear structure–activity trends. Gallic acid showed the strongest DPPH scavenging (half-maximal inhibitory concentration, IC₅₀ = 4.45 µmol/L) and reducing power (17.26 µmol TE/mg), while quercetin was consistently active across all four endpoints. Eriocitrin (IC₅₀ = 2.47 µmol/L) and rutin (IC₅₀ = 2.66 µmol/L) were particularly effective in the ABTS assay, showing that glycosylation does not abolish cation-radical scavenging. Lipinski’s Rule of Five and Veber oral-bioavailability criteria place these findings within a drug-likeness context. The results also highlight the limitations of the Folin–Ciocalteu assay as a standalone measure of total phenolic content, since its response depends strongly on hydroxylation density. Rather than asserting therapeutic efficacy, this work provides a harmonized comparative dataset identifying phenolic substructures with the strongest and most consistent redox activity, together with the structural drivers underlying these patterns.

Microwave irradiation has become a routine technique in homogeneous and effective heating in organic synthesis. However, its application in enzyme-containing reactions is limited since it can cause denaturation of the enzyme. In this study, we have briefly investigated the effect of microwave heating on the conjugation reaction of horseradish peroxidase (HRP) with aldehyde derivative of dextran (D-CHO). The reaction was irradiated by microwave at 50 °C for 5 min. The conjugate was confirmed via GPC, in which the conjugates of HRP and D-CHO coexist with free unbound HRP molecules. Activity studies of HRP revealed that there is a small decrease in conjugate activity relative to the free enzyme after a short bioconjugation reaction with microwave irradiation. In decolorization studies of the textile dye Reactive Blue 19 (RB19), 99% of RB19 was decolorized through the free enzyme at 35 °C while the decolorization of the dye was 96% at 25?35 °C by the conjugate, which is a critical result showing clearly that the HRP conjugated via D-CHO is not denatured and still active after microwave-assisted reaction. This phenomenon is due to the multiple point conjugation of D-CHO on the surface of HRP and locking the 3D structure which may prevent changes in the secondary or tertiary structure of the enzyme. The results reveal that microwave irradiation can be used in production of covalently modified enzymes.

Equisetum telmateia Ehrh. (great horsetail) belongs to the Equisetaceae family and its aerial parts have been traditionally used for skin conditions and to achieve healthy and resilient skin, nails, and hair. This study aimed to evaluate the inhibition of skin-related enzymes by, the antioxidant capacity of, and the phytochemical composition of E. telmateia. Additionally, a novel emulgel was formulated from the main methanolic extract and characterized in terms of pH, viscosity, determination of content quantification, textural profile analysis, and spreadability. After the characterization studies, in vitro release and ex vivo permeation and penetration studies were performed. Firstly, the dried aerial parts of E. telmateia were macerated in methanol, followed by partitioning with solvents of increasing polarity: n-hexane, chloroform, ethyl acetate, and n-butanol. Antioxidant activity was assessed using DPPH, FRAP, CUPRAC, and TOAC assays, while enzyme inhibition was analyzed for collagenase, elastase, hyaluronidase, and tyrosinase. LC-MS/MS analysis identified 53 phytochemical compounds. Protocatechuic acid, the main phenolic compound, was quantitatively analyzed in each subfraction by HPTLC. The in vitro release studies showed sustained release of the reference substance (protocatechuic acid) and the kinetic modeling of the release was fitted to the Higuchi model. The ex vivo permeation and penetration studies showed that the formulation exhibited a retention of 3.06 ± 0.21 µg.cm⁻² after 24 h, whereas the suspended extract demonstrated a skin retention of 1.28 ± 0.47 µg.cm⁻². Both the extracts and the formulated emulgel exhibited inhibitory effects on skin-related enzymes. Our finding suggested that E. telmateia might be a valuable ingredient for wrinkle care and skin-regenerating cosmetics.