Sulfonic acid-functionalized k-carrageenan/Cr-based metal-organic framework: An efficient and recyclable catalyst for fructose conversion to 5-hydroxymethylfurfural

A novel bio-based catalyst was developed by in-situ forming Chromium(III) (Cr)-based metal-organic framework, MIL-101(Cr), in the presence of k-carrageenan (k-Car) and followed by a post-synthetic modification to introduce additional -SO3H functional groups into the composite structure of k-Car/MIL-101(Cr). Different analyses were conducted to confirm the successful catalyst formation. The catalyst performance was evaluated in the solid acid catalyzed dehydration of fructose to 5-hydroxymethylfurfural. The Response Surface Method (RSM) optimization determined that employing 33 wt% of the catalyst at 105 °C for 40 min resulted in a remarkable 97.8 % yield. The catalyst demonstrated suitable recyclability, maintaining its catalytic efficiency over four cycles. Comparative studies with k-Car and the non-sulfonated composite highlighted the superior activity of the catalyst, emphasizing the synergy between the k-Car, MIL-101(Cr) and the influence of -SO3H post-functionalizing on the catalytic performance.

Sulfonic acid-functionalized chitosan-metal-organic framework composite for efficient and rapid conversion of fructose to 5-hydroxymethylfurfural

In pursuit of designing a bio-based catalyst for the dehydration of biomass (i.e., fructose) to 5-hydroxymethylfurfural, a novel catalytic composite was prepared by in-situ formation of an Al-based metal-organic framework in the presence of chitosan. To enhance the acidity of the as-prepared catalyst, it was sulfonated with chlorosulfonic acid. Various characterization techniques, including XRD, XPS, FTIR, SEM/EDX, TGA, and elemental mapping analysis were applied to validate the formation of the acidic composite. Fructose dehydration conditions were also optimized using Response Surface Method (RSM) and it was found that reaction in the presence of catalyst (23 wt%) in DMSO, at 110 °C for 40 min led to the formation of HMF in 97.1%. Noteworthy, the catalyst was recyclable and stable up to five runs with a minor reduction in its activity.

Cyclodextrin Host-Guest Recognition in Glucose-Monitoring Sensors

Diabetes mellitus is a prevalent chronic health condition that has caused millions of deaths worldwide. Monitoring blood glucose levels is crucial in diabetes management, aiding in clinical decision making and reducing the incidence of hypoglycemic episodes, thereby decreasing morbidity and mortality rates. Despite advancements in glucose monitoring (GM), the development of noninvasive, rapid, accurate, sensitive, selective, and stable systems for continuous monitoring remains a challenge. Addressing these challenges is critical to improving the clinical utility of GM technologies in diabetes management. In this concept, cyclodextrins (CDs) can be instrumental in the development of GM systems due to their high supramolecular recognition capabilities based on the host-guest interaction. The introduction of CDs into GM systems not only impacts the sensitivity, selectivity, and detection limit of the monitoring process but also improves biocompatibility and stability. These findings motivated the current review to provide a comprehensive summary of CD-based blood glucose sensors and their chemistry of glucose detection, efficiency, and accuracy. We categorize CD-based sensors into four groups based on their modification strategies, including CD-modified boronic acid, CD-modified mediators, CD-modified nanoparticles, and CD-modified functionalized polymers. These findings shed light on the potential of CD-based sensors as a promising tool for continuous GM in diabetes mellitus management.

Ultrasound-assisted synthesis of MIL-88(Fe) coordinated to carboxymethyl cellulose fibers: A safe carrier for highly sustained release of tetracycline

For stopping long-time harmful bacterial infection, designing a drug carrier with a highly prolonged release profile is a promising approach that is of interest to different biomedical areas. The subject of this work is to synthesis a novel carrier system through coordination of MIL-88(Fe) to carboxymethyl cellulose (CMC) for enhancing interaction between drug and carrier. We established an ultrasound-assisted synthetic method for in situ synthesis of MIL-88(Fe) in the presence of CMC resulting in CMC/MIL-88(Fe) composite. The CMC/MIL-88(Fe) was loaded with a high amount of Tetracycline (TC) by immersion of carrier to the TC aqueous solution. The release profile in the simulated physiological conditions, pH 7.4, revealed a low initial burst release followed by a sustained and prolonged release over 384 h. The in vitro cytotoxicity of CMC/MIL-88(Fe) against Human skin fibroblast (HFF-1) cells was calculated by MTT assay and showed a good cytocompatibility. The antibacterial activity was found for TC-loaded CMC/MIL-88(Fe) toward both E. coli and S. aureus with MIC 64 mg·ml^-1.

Synbiotic Supplementation Improves Metabolic Factors and Obesity Values in Women with Polycystic Ovary Syndrome Independent of Affecting Apelin Levels: A Randomized Double-Blind Placebo - Controlled Clinical Trial

Background

This research investigated the symbiotic supplement influences on serum glycemic indices and lipids as well as apelin rates and obesity values in polycystic ovary syndrome (PCOS) patients.

Materials and Methods

A total of 68 obese or overweight patients (20-44 years old) with PCOS were enrolled to conduct a randomized double-blinded placebo-controlled clinical trial. A total of 34 people in the synbiotic group received a synbiotic supplement and 34 people in the placebo group received placebo, daily for 8 weeks. Fasting blood specimens, anthropometric measurements and dietary intake data were gathered three times during the study. The information was analyzed by independent t test, paired t test, analysis of covariance and chi-square test.

Results

Synbiotic supplementation significantly decreased serum fasting glucose (P=0.02), insulin (P=0.001), homeostatic model assessment for insulin resistance (IR, P=0.001), weight (P=0.02), body mass index (BMI, P=0.02), waist circumference (WC, P=0.01), hip circumference (HC, P=0.02), and waist-to-height ratio (WHtR, P=0.02) but significantly increased high-density lipoprotein (HDL) cholesterol (P=0.02) compared to the placebo. At the end of the trial, no significant differences were seen in serum total cholesterol, triglyceride (TG), low-density lipoprotein (LDL) cholesterol, or apelin levels as well as waist-to-hip ratio (WHR) between the two groups.

Conclusion

Synbiotic supplementation improved glycemic indices, lipid profile and obesity values in women with PCOS. These beneficial effects were not related with alterations in serum apelin levels (Registration number: IRCT20100408003664N19).

Spectroscopic and molecular docking investigation of polynucleotides and DNA binding affinity to Nile blue dye

We used UV-vis absorption spectroscopy, fluorescence spectrophotometry and molecular docking calculations to investigate intermolecular interaction between the cationic dye, Nile blue (NB), and synthetic polynucleotides, poly(A-T), poly(G-C) and calf thymus DNA (Ct-DNA) at physiological pH. Strong hypsochromic absorbance and fluorescence quenching were observed that showed strong binding of NB to these polynucleotides and DNA. The binding affinity values derived from maximum absorption of the spectra of NB bound to various polynucleotides and Ct-DNA concentrations suggests that NB exhibits greater binding affinity to poly(G-C) than to poly(A-T). The thermodynamic parameters suggested that hydrogen bonds and van der Waals forces might play a major role in the binding of NB to DNA. The molecular docking results suggested that NB was an intercalator of the stacked base pairs of Ct-DNA.

Direct C–S bond formation via C–O bond activation of phenols in a crossover Pd/Cu dual-metal catalysis system

A highly effective synthesis of unsymmetrical aryl sulfides was introduced under a dual-metal (Pd/Cu) catalysis system with a high turn-over number.

Immunomodulatory efficacy of ethanol extract of propolis on tumor-bearing mice with disseminated candidiasis

OBJECTIVE

This study was aimed at investigating the effect of propolis on immunosurveillance by measuring the levels of serum interleukin (IL)-4, IL-10, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-γ in tumor-bearing mice with disseminated candidiasis.

METHODS

The ethanol extract of propolis was selected for this study. Balb/C female mice were infected with Candida albicans (C. albicans) and inoculated with spontaneous mouse mammary tumor (SMMT). The serum levels of tissue inhibitor of metalloproteinase-1(TIMP-1) were assessed by enzyme- linked immunosorbent assay (ELISA). Mice were treated daily with propolis solution (100mg/kg, 0.1 mL, orally) for 3 days before IV challenge with C. albicans and SC challenge with SMMT and continued for 10 days. The rates of survival and tumor growth of understudy mice were investigated as well. The levels of TNF-α, IFN-γ, IL-4, IL-10 and IL-17 cytokines in culture supernatants were determined by ELISA.

RESULTS

The mean tumor size was significantly increased in tumor-bearing mice infected with C. albicans (16.98 ± 0.49 mm(2)) as compared to other mice groups (P<0.05). The results showed a significant decline of IL-4 and IL-10 levels after propolis administration to tumor-bearing mice infected with C. albicans (53.41 pg/mL, 156.81 pg/mL and 63.45 pg/mL) (P < 0.05). The increment of TNF-α (433.85 pg/mL) and IFN-γ (120.43 pg/mL) levels were also observed.

CONCLUSION

Data revealed that propolis has remarkable immunomodulatory effect, which provides a scientific validation for the popular use of this natural substance, and further investigation will help to understand propolis usefulness during immunosuppressive conditions.