Phenolic Groups Research Articles

A Systematic Study of the Structural Properties of Technical Lignins

Technical lignins are globally available and a sustainable feedstock. The unique properties of technical lignins suggest that these materials should have several industrial applications. The main proposal of this study is to evaluate the relationship between the structure and properties of two technical lignins. Morphological, chemical, physical, and thermal properties of sodium lignosulfonate (LGNa) and magnesium lignosulfonate (LGMg) were investigated. The results showed that a higher formation of intramolecular hydrogen bonds may occur in lignins with a higher content of phenolic hydroxyl groups, such as LGMg. As a result, an increase in the energy of hydrogen bonds in the lignosulfonate structure was observed, without significant change in the hydrogen bond distances. In addition, higher content of phenolic hydroxyl groups might also reduce lignosulfonates thermal stability. The combustion index value was three times higher for LGMg than for LGNa. The characterization study also revealed that phenolic hydroxyl groups influence the main properties of technical lignins and can be a determining factor when these lignosulfonates are used in industrial applications.

Organic Crosslinked Tin Oxide Mitigating Buried Interface Defects for Efficient and Stable Perovskite Solar Cells

AbstractTin dioxide (SnO2) stands as a promising material for the electron transport layer (ETL) in perovskite solar cells (PSCs) attributed to its superlative optoelectronic properties. The attainment of superior power conversion efficiency hinges critically on the preparation of high‐quality SnO2 thin films. However, conventional nanoparticle SnO2 colloids often suffer from inherent issues such as numerous oxygen vacancy defects and film non‐uniformity. In this study, we report a strategy to homogenize SnO2 with reduced defects for high‐performance PSCs. The commercial SnO2 colloid is modulated with bisphenol S (BPS) crosslinking to achieve a better annealing intermediate state. The phenolic hydroxyl groups on BPS bond with the hydroxyl groups on the SnO2 surface, passivating defects as well as promoting superb regularity of the films by forming a network of the SnO2 nanoparticles. Additionally, the sulfone groups on BPS coordinate with Pb2+, regulating the crystallization of PbI2 and FAPbI3, which leads to better interface contact at the buried interface. The FAPbI3 perovskite solar cells based on BPS‐crosslinked SnO2 layers achieved a champion efficiency of 24.87 % and retained 95 % of their initial PCE after 1000 hours of continuous light soaking under N2 atmosphere.

Molecular structure characteristic of coals of different rank.

Understanding the structural characteristics of coal at the molecular level is fundamental for its effective utilization. To explore the molecular structure characteristic, the long-flame coal from Daliuta (DLT), coking coal from Yaoqiao (YQ), and anthracite from Taixi (TX) were investigated using various techniques such as elemental analysis, Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy. Based on the structural parameters, the coal molecular model was constructed and optimized. The molecular formula of DLT was C193H178N2O47, that of YQ was C201H179N3O30S, and that of TX was C198H118N2O10. With an increase in the degree of metamorphism, the substitution of the benzene ring gradually shifted towards lower levels of substitution. The content of long chain in the aliphatic chain decreased while the content of branched chains kept increasing. The percentage of aromatic ether increased gradually, while the phenolic hydroxyl group initially decreased but then increased. The carboxyl group C = O decreased and eventually disappeared in anthracite coal. The proportion of pyrrole nitrogen gradually increased while that of pyridine nitrogen and protonated pyridine gradually decreased. The 2D planar structure of coal was constructed using ChemDraw, ACD/CNMR Predictor, and gNMR programs. The geometry optimization was performed using the COMPASS II force field within the Forcite module in Materials Studio 2020. The annealing process employed NVT ensemble at a simulation temperature of 298K. The Amorphous Cell module in Materials Studio was used to construct large-scale 3D molecular models, with the set parameters in this paper.

Presence of Humic Acids in Landfill Leachate and Treatment by Flocculation at Low pH to Reduce High Pollution of This Liquid

Humic substances are abundant in landfill leachate, especially humic acids, which are insoluble at low pH in aqueous solutions. Focusing on the chemical properties of humic acids, we describe in this work a new method for a sustainable treatment of landfill leachate originated from solid wastes, which consists of the reduction of organic load (COD, chemical oxygen demand) and colour and is based in the gradual decrease in pH to the value in which HAs are insoluble in water solution. Zeta potential values mark the chemical stage of humic acids because of ionisation–protonation of the phenolic and carboxylic groups, and this parameter is monitored during flocculation, changing from −16.8 mV at pH 7.7 to 0.0068 mV at pH 2.0, when HAs precipitate. The final result is the reduction in the organic matter content (COD) and colour in the leachate, 86.1% and 84.7%, respectively. Solids produced by precipitation during the acidification treatment have been characterized by elemental chemical analysis and Fourier transform infrared spectrometry, concluding a high similarity in chemical composition with commercial and natural humic acids. Protonated humic acids at low pH can interact with other molecules by hydrogen bonds and form bigger molecular structures much more unstable in suspension, which conduct to precipitation. The mean diameter of the humic acids aggregates was measured, detecting the formation of big molecular structures at low pH. This process is analysed and compared economically with other processes proposed for landfill leachate treatment, resulting in a promising technique for the management of this residue.

A Complete Description of the Ultrafast Proton Transfer Dynamics in the Excited State of D-Luciferin.

Excited-state proton transfer (ESPT) in organic photoacids is a widely studied phenomenon in which D-luciferin is of special mention, considering the fact that apart from its phenolic OH group, the nitrogen atoms at either of the two thiazole moieties could also participate in hydrogen bonding interactions with a proton-donating solvent during ESPT. As a result, several transient species could appear during the ESPT process. We hereby deploy subpicosecond time-resolved fluorescence upconversion (FLUP) and transient absorption (TA) spectroscopic techniques to understand the detailed photophysics of D-luciferin in water as well as in dimethyl sulfoxide (DMSO) and ethanol. These transient-state spectroscopic studies reveal the population of two kinds of hydrogen-bonded (HB) complexes (HBCs) in the excited singlet (S1) state─HBC-I, which is formed at the OH site of the hydroxy benzothiazole moiety with a proton-accepting solvent, and the other one is HBC-II, which is formed at the N atom site of the thiazoline moiety with a proton-donating solvent. This study provides a complete description of the mechanism of the deprotonation process in HBC-I through distinct identification and characterization of the spectroscopic properties and temporal dynamics of those transient species associated with the four stages of the ESPT process as proposed by the Eigen-Weller model. This study also identifies and characterizes HBC-II, which, however, does not participate in the deprotonation process but provides an efficient nonradiative relaxation mechanism via geminate proton recombination.

Stable Antifouling and Antibacterial Coating Based on Assembly of Copper-Phenolic Networks.

Biofilm formation on medical devices has become a worldwide issue arising from its resistance to bactericidal agents and presenting challenges to eradicating biofouling adhesion, especially in biological fluids. Metal-phenolic networks have been demonstrated as a versatile and efficient strategy to prevent biofilm formation by endowing medical devices with prolonged antifouling and antibacterial activities in a one-step surface modification. In this study, we report a simple and environmentally friendly method using coordination chemistry between copper ions (Cu2+) and dopamine-containing copolymer to fabricate metal-phenolic network-based coatings. The phenolic groups also imparted the adhesion of glycopolymer-containing dopamine residues to inorganic and organic substrates, resulting in dual antifouling and bactericidal surfaces. 2-gluconamidoethyl methacrylamide monomer (GAEMA) was first copolymerized with dopamine methacrylamide (DMA) using a free-radical polymerization process. The resulting copolymer (GAEMA-DMA), denoted as GADMA, was then mixed with copper ions in a one-step process to form the GADMA-Cu coating. The GADMA-Cu coating was hydrophilic and significantly reduced the water contact angle (WCA) and adsorption of bovine serum albumin protein even after incubation in a bovine serum albumin solution for 30 h. Moreover, the coating exhibited strong antibacterial activity against Escherichia coli and Staphylococcus aureus and was biocompatible with 99% cell viability toward normal human fibroblast (HDFa) cells. Thus, our coating shows great potential for application in medical devices.

Enzymatic modification of dihydromyricetin by glucosylation and acylation, and its effect on the solubility and antioxidant activity.

Although dihydromyricetin exhibits strong potential for pharmaceutical applications, its limited aqueous solubility, permeability and stability restrict its use. In this work, we have synthesized a series of glucosides and acyl-glucosides of dihydromyricetin that could increase the bioavailability of this molecule. First, the R134A variant of sucrose phosphorylase from Thermoanaerobacterium thermosaccharolyticum catalyzed the formation of three monoglucosides, and the major one was identified as dihydromyricetin 4'-O-α-D-glucopyranoside (>75% conversion yield). The molecular features that define this specificity for the 4'-OH phenolic group were investigated through induced-fit docking analysis of each potential derivative. Furthermore, the acylation of the 4'-monoglucoside with fatty acid vinyl esters (C8, C12, and C16) was performed with high efficiency using the lipase from Thermomyces lanuginosus. Three novel acyl derivatives of dihydromyricetin were characterized. Furthermore, the water solubility and antioxidant activity (ABTS, DPPH) of the synthesized compounds were measured, concluding that the location of the glucosyl moiety may affect their physicochemical properties and, as a result, their bioactivity.

Pyrolysis of sawdust in a horizontal tube furnace: Effects of temperature and heating rate on product composition

The abundant sawdust waste from the timber production industries in Malaysia can be a potential biomass feedstock for pyrolysis process. However, the understanding of product composition and bio-oil quality from sawdust pyrolysis remains limited in Malaysian’s context. In this study, pyrolysis of sawdust was conducted in a horizontal tube furnace to investigate the effects of temperatures (400-550 °C) and heating rates (10-20 °C/min) on the composition of products, quality and properties of bio-oil. According to Gas chromatography (GC) analysis, phenol group appears to be the major compound in the bio-oil. The chemical components of bio-oil were found to be richer at lower reaction temperatures (400-450 °C), where it showcased the presence of phenols, ketones, carboxylic acids, furans, aldehydes, alkenes, alcohols, ether and amine. At increased reaction temperatures (500–550 °C), the process favoured the production of catechol (17%). The yield of bio-char decreased with increasing temperatures and heating rates due to the loss of volatile matter, and 400 °C proved to be the optimum temperature for maximum biochar yield. The biochar also displays porous structure, with increased adsorption capacity. Since the pyrolysis of sawdust could produce phenolic compounds, it appears to be a potential feedstock for biomass pyrolysis.

Enhanced removal of phenolic contaminants with permanganate oxidation mediated by SiO2@TEMPO: Performance, transformation pathway, and selectivity

The core bottleneck in water decontamination lies in trigging the selective removal of trace contaminants in the presence of complex water matrices, overcoming the inevitable consumption of oxidants and energy input by the water matrix. Here, the selective removal of phenolic contaminants with permanganate (PM) oxidation mediated by 2,2,6,6-tetramethylpiperidinooxy (TEMPO)-functionalized silica (SiO2@TEMPO) was firstly reported. SiO2@TEMPO was synthesized by covalently bonding 4-oxo-2,2,6,6-tetramethylpiperidinooxy onto SiO2 through a 3-aminopropyltriethoxysilane bridge. The loading capacity of Wt% for nitrogen element in SiO2@TEMPO are 1.01–1.27 %. The degradation rate of tetracycline (around 1.50 min−1) with SiO2@TEMPO/PM are around 15 folds higher than that with PM, attributed to the formation of the reactive N-oxoammonium cation via single-electron transfer during PM oxidation. SiO2@TEMPO exhibited excellent stability and recyclability after five consecutive cycles of tetracycline degradation. Three transformation pathways (hydroxylation, demethylation, and dehydration) for tetracycline degradation by SiO2@TEMPO/PM were proposed based on the identification of 36 transformation products using HPLC/Q-Orbitrap HRMS. Thereinto, the attack of the N-oxoammonium cation in SiO2@TEMPO on the phenolic hydroxyl group to form corresponding hydroxylation and quinylation products accounted for the dominant degradation pathway. SiO2@TEMPO/PM also demonstrated remarkable adaptability across a wide pH range of 5.0–9.0, indicating its potential for practical applications. The significant resistance to the inhibitory effects of co-existing water matrix components (humic acid, cations and anions), along with the marked differences in degradation efficiency between phenolic and non-phenolic contaminants, demonstrate the selectivity of SiO2@TEMPO/PM towards phenolic contaminants. These results offer new insights into the selective removal of phenolic contaminants and pave the way for the development of efficient and sustainable strategies for water remediation.

Removal of tetracycline by biochar synergistic with ferrate: Influencing mechanism on precursor biomass components.

Biochar can serve as an activator for potassium ferrate, significantly enhancing the treatment efficiency to antibiotics. However, the mechanism by which biochar activated potassium ferrate remained unclear, necessitating further investigation. Cellulose biochar (CBC) and lignin biochar (LBC) derived by two model compounds which were the highest proportion of content in biomass were adopted to be study object, to investigate the removal efficiency of tetracycline (TC) by ferrate synergetic with CBC and LBC, respectively for the first time, and thoroughly analyzed the adsorption and degradation processes within the reaction system. It is noteworthy that CBC contributed to this synergy primarily through the phenolic hydroxyl groups which facilitated the decomposition of ferrate and increase the generation of intermediate valence iron species, thereby improving removal rates. Whereas, LBC enhanced removal rates of TC mainly across its own adsorption capabilities. This also resulted in LBC manifesting excellent synergistic effects under various pH environments, while the CBC system was primarily suited for alkaline conditions. This study provided new theoretical support for the efficient utilization of ferrate in organic wastewater treatment and offered a novel perspective on the precise control of structure in the process of biochar material prepared by agricultural and forestry solid waste biomass.

ADSORPTION PROCESS OF PESTICIDE ON SWCNT FUNCTIONALIZED AND CROSSLINKED WITH CHITOSAN USING PM3 SEMI-EMPIRICAL METHOD AND MONTE CARLO SIMULATION

In this work, using the PM3 semi-empirical method, the oxidation of the single-walled carbon nanotube (SWCNT) was studied by sulfuric and nitric acid for the incorporation of carbonyl (C=O), phenol (OH) and carboxylic (COOH) groups in the C=C bonds present on the surface of the nanotube. Subsequently, the crosslinking of the oxidized SWCNT (SWCNTox) and chitosan (Q) was observed through hydrogen bonds of the C=O and OH bonds with 2.34 Å, the process was endothermic and soluble in polar solvents due to the presence of OH and NH groups in the structure of SWCNTox/Q. The Monte Carlo modeling allowed to study the adsorption of pesticides in the SWCNTox/Q at different temperatures, where the QSAR (quantitative structure activity relationship) properties allowed predicting the behavior of the pesticides, that is, the degree of hydrophobicity (log P) and accessible surface area (ASA) were important parameters in the evaluation of SWCNTox/Q as an adsorbent and surface interacting with pesticides respectively. Finally, the adsorption was a physisorption process due to the electronegativity of the CO, OH, NH2, NH and C=O bonds.

Evaluating the Effectiveness, Safety, and Satisfaction Rates of Phenol 90%, Trichloroacetic Acid 100%, and Radiofrequency in Lateral Matricectomy for the Treatment of Ingrown Toenails: A Triple-Arm Clinical Trial.

This study aimed to evaluate the effectiveness, safety, and satisfaction rates of three different lateral matricectomy methods for treating ingrown toenails: 90% phenol, 100% trichloroacetic acid (TCA), and radiofrequency (RF) ablation. Our objective was to identify which method offers superior outcomes regarding postoperative pain, healing time, aesthetic results, and complication rates. Conducted between August 2022 and June 2023, the study included 12 eligible patients divided into three groups: Group 1 underwent lateral matricectomy with 90% phenol, Group 2 with 100% TCA, and Group 3 with RF treatment. Preoperative assessments were conducted, and patients were followed up on the day after surgery and at Weeks 1, 2, and 3, as well as at Months 1, 2, 6, and 9 postoperatively (totaling nine assessments). Pain levels were measured using the Visual Analog Scale (VAS), while wound discharge and bleeding were rated on specified scales. Mean pre- and postoperative (second day) pain scores were 6.0 ± 3.3 and 0.75 ± 0.67 for Group 1, 6.25 ± 4.92 and 1.75 ± 0.58 for Group 2, and 6.25 ± 2.25 and 3.50 ± 0.50 for Group 3, with significant differences observed. RF treatment showed higher moderate postoperative pain compared to mild pain in the phenol and TCA groups. Average healing time was 22.75 ± 3.50 days (phenol), 40 ± 12.91 days (TCA), and 26.25 ± 6.70 days (RF), with phenol demonstrating faster healing, although differences were statistically insignificant. The median aesthetic outcomes favored phenol with a score of 5.0. Lateral matricectomy with 90% phenol, 100% TCA, and RF all provide unique advantages for ingrown toenail treatment. Phenol exhibited high success rates, minimal complications, faster healing, and excellent aesthetic outcomes. IRCT, IRCT20220228054152N1. Registered 03 January 2023, https://www.irct.behdasht.gov.ir/trial/65907.

Application of Oil Extracted from Cashew Nut Peel (Anacardium occidentale) as an Antioxidant for Biodiesel

The present work aims to extract and test cashew nut peel oil as a natural antioxidant in the oxidative stabilization of biodiesel. Therefore, determinations of the ideal time of Soxhlet and thermal extractions, Fourier transform infrared spectroscopy (FTIR) analyses, and evaluation of the oxidative stability by Rancimat method were carried out. FTIR analyses revealed that the 3rd cycle of extraction was sufficient to extract all the oil, with an average yield of 30.0%. For the thermal extraction of the laboratory technical cashew nut peel oil, the best extraction, based on statistical analysis, was 60 min, yielding 20.0%. The FTIR analysis of the extracted cashew nut peel oil showed characteristic peaks of phenolic groups and organic acids, showing differences in the intensities of the absorption bands. The oxidative stability showed induction period of 8 h 40 min for the hydraulic press extraction, 10 h 35 min for the Soxhlet extraction, and 10 h 65 min for the industrial technical extraction of the cashew nut peel oil. All values were below the 12-h limit established by the National Agency for Petroleum, Natural Gas and Biofuels (ANP). The technical cashew nut peel oil extracted in the laboratory presented an induction period of 11 h 12 min, close to that recommended by ANP, proving to be a promising natural antioxidant. Cardanol presented satisfactory results with 25 h 22 min, double that suggested by ANP. Thus, cashew nut peel oil showed important and promising results as a natural antioxidant for biodiesel.

Self-assembled water soluble and bone-targeting phosphorylated quercetin ameliorates postmenopausal osteoporosis in ovariectomy mice.

Natural compounds have shown promising application prospects in preventing or treating various diseases, including osteoporosis on account of their abundant sources, low price, multi-targeting and multiple biological effects. As a bioactive natural product, quercetin (Que) has previously demonstrated to ameliorate osteoporosis (OP), however, its poor bioavailability resulting from low water solubility, poor stability and lack of bone-targeting largely restricted its efficacy and clinical applications. Inspired by the bone-targeting capability of phosphate compounds, we reported a one-step procedure for synthesis of phosphorylated Que (p-Que) by direct phosphorylating phenol groups of Que for the first time. The phosphate groups on p-Que could not only improve the water dispersibility of Que, but also endow p-Que desirable bioavailability and bone-targeting feature. The results from biological assays suggested that p-Que could inhibit osteoclastogenesis and bone resorption and alleviate trabeculae loss in osteoporotic mice. In conclusion, this work demonstrated that phosphorylation strategy can effectively solve low water solubility, lack of bone-targeting capability and poor bioavailability of natural compounds, providing a novel and efficient approach for development of OP nanomedicines.

Expose the bioactive properties of Picrorhiza kurroa root extract oil (PKEO): phytochemical composition and therapeutic activities

Background: The present study aims to explore the bioactive properties of essential Oil (PKEO) derived from Picrorhiza kurroa (commonly known as kutki), a medicinal plant known for its therapeutic potential. Picrorhiza kurroa essential oil has a distinct chemical profile, which sets it apart from other essential oils. The bioactive compounds present in Picrorhiza kurroa essential oil may lead to the development of new drugs, particularly for treating inflammatory and oxidative stress-related disorders. The research aims to study the extraction, phytochemical composition, and various biological activities of PKEO. Methodology: Oil obtained through hydro-distillation contains various phytochemical compounds, including steroids, triterpenoids, alkaloids, phenols, proteins, flavonoids, and tannins. Its bioactivity and aroma are attributed to its phenolic and sesquiterpene esters. Results and Discussion: The total phenolic content is 250.47 μg GAE/g, and the total flavonoid content is 245.26 μg QE/g. UV-visible and IR spectroscopic analyses confirm the presence of phenolic and terpenoid ester functional groups. PKEO has moderate antioxidant activity, with IC50 values of 98.19 µg/mL in DPPH scavenging and 42.72% inhibition in the ABTS assay. It also exhibits dose-dependent inhibition of protein denaturation and HRBC stabilizing activity. Antimicrobial tests show PKEO inhibits E. coli growth, indicating potential antibacterial properties. Conclusion: These findings highlight PKEO's promising bioactive profile, suggesting potential therapeutic and cosmetic formulation applications. The antifungal activity also shows the potential antifungal effects of the PKEO.

Chemical profiling and clustering of Piperaceae revealed by volatilomics analysis

The Piperaceae family is one of the aromatic plants that have a distinctive odor and is known to have tremendous benefits in human life. Piperaceae is used as raw material for medicines, spices, antibacterial, antiviral, and insecticides. Research on the composition of volatile chemical compounds in Piperaceae members is still limited. This study aims to extract volatile chemical compounds in the Piperaceae family and classify Piperaceae members based on their volatile compounds. The type of research is laboratory research. The research samples were leaves of ten species of Piperaceae members, namely Piper cubeba, P. nigrum, P. betle, P. ornatum, P. retrofractum, P. sarmentosum, Peperomia pellucida, Peperomia scandens, Peperomia caperata, and Peperomia maculosa. The research instrument was an observation sheet of SPME-GCMS analysis results. Data in the form of metabo-analysis was obtained from laboratory analysis using SPME-GCMS by producing a comprehensive volatile compound profile of the Piperaceae family and revealing differences between species. The results of SPME-GCMS analysis on the Piperaceae family obtained 197 identified volatile chemical compounds. The largest group of chemical compounds in 10 species of the family consists of sesquiterpene (16.2%), monoterpene (11.7%), sesquiterpenoid (7.1%), alcohol (6.1%), aldehyde (4.6%), terpene (4.1%), terpenoid (4.1%), alkene (3%), fatty acid (2.5%), ketone (2.5%), phenol (2.5%), alkane (2%) and other groups less than 2%. Characteristics of typical compounds in the genus Peperomia amounted to 10, namely Alpha-pinene, (-)-; Camphene; 2-beta-pinene; l-Limonene; Nonanal; (-)-.beta.-Elemene; alpha.-Copaene; Germacrene D; cis-caryophyllene; Bicycloelemene. In the genus Piper, the variation in the character of volatile chemical compounds is very large, typical characteristics possessed by 6 Piper species are alpha-pinene, (-)-; alpha.-Copaene; alpha.-Humulene; (-)-beta.-Elemene; and trans-Caryophyllene. The study concluded that 197 volatile compounds from 10 Piperaceae species had been identified. The results of this study can be recommended that the Piperaceae family can be optimized for public health.

Extraction and chemical characterization of humic acid produced from lignite coals of arid region of Gujarat, Western India

In the current study, extraction of humic acid (HAs) from lignite fines of kutch basin of Gujarat (western India) were reported. The extraction was done by International Humic Substances Society (IHSS) method. Several analytical and spectroscopic techniques were used to characterize of extracted HAs. The gravimetric analysis showed (28.5% and 26.4%) of humic acid extraction from panandhro mines (PM) and mata-No-Madh mines (MNMM) respectively. UV–Vis spectroscopy revealed a high degree of humification, higher stability and aromatic nature. FTIR peaks demonstrated the presence of carboxylic, alcoholic, and phenolic functional groups. SEM/EDX analysis revealed that surface were smooth, non-porous and like loose sponge that showed the presence of major elements like C, O, F, Al, Na, S, Si, Ca, Ti and Fe. The combination of results gives a better and improved understanding of the nature of lignite coals of western India. It may be helpful in choosing suitable coals for the extraction of humic acid and using it for enhancing plant growth condition, soil enrichment and creating green energy solution. This study not only helps in the research related to extraction of humic acid from lignite but also creates a new avenue for the efficient and clean use of lignite.

Cationized Cellulose Materials: Enhancing Surface Adsorption Properties Towards Synthetic and Natural Dyes.

Cellulose is a homopolymer composed of β-glucose units linked by 1,4-beta linkages in a linear arrangement, providing its structure with intermolecular H-bonding networking and crystallinity. The participation of hydroxy groups in the H-bonding network results in a low-to-average nucleophilicity of cellulose, which is insufficient for executing a nucleophilic reaction. Importantly, as a polyhydroxy biopolymer, cellulose has a high proportion of hydroxy groups in secondary and primary forms, providing it with limited aqueous solubility, highly dependent on its form, size, and other materialistic properties. Therefore, cellulose materials are generally known for their low reactivity and limited aqueous solubility and usually undergo aqueous medium-assisted pretreatment methods. The cationization of cellulose materials is one such example of pretreatment, which introduces a positive charge over its surface, improving its accessibility towards anionic group-containing molecules or application-targeted functionalization. The chemistry of cationization of cellulose has been widely explored, leading to the development of various building blocks for different material-based applications. Specifically, in coloration applications, cationized cellulose materials have been extensively studied, as the dyeing process benefits from the enhanced ionic interactions with anionic groups (such as sulfate, carboxylic groups, or phenolic groups), minimizing/eliminating the need for chemical auxiliaries. This study provides insights into the chemistry of cellulose cationization, which can benefit the material, polymer, textile, and color chemist. This paper deals with the chemistry information of cationization and how it enhances the reactivity of cellulose fibers towards its processing.

Synthesis, characterization and measurement of antimicrobial activity of (6Z,15Z)-4,18-dioxa-9,13-dithia-7,15-diaza-1,2(1,4),5,8,11,14,17(1,2)- heptabenzenecyclononadecaphan-6,15-diliene and its palladium(II) chloride complex

To synthesize the Schiff base with the desired properties, a transition from a monomeric molecule to a macrocyclic structure was made. For this purpose; (oxy)-dibenzaldehyde dibenzaldehyde derivative, (oxy)bis(N-prop)-1-en-2-yl-aniline derivative, (oxy)-dianiline derivative and (sulfanediyl)-dianiline compounds were obtained at the end of four different reaction processes. In the last step of these reactions, a macrocyclic compound (6Z,15Z)-4,18-dioxa-9,13-dithia-7,15-diaza-1,2(1,4),5,8,11,14,17(1,2)-heptabenzenecyclononadecaphan- 6,15-diene Schiff base was obtained by condensation method. As a result of the reaction of this product with PdCl2, (6Z,15Z)-4,18-dioxa-9,13-dithia-7,15-diaza-1,2(1,4),5,8,11,14,17(1,2)-heptabenzenecyclononadecaphan-6,15-dylene palladium(II) chloride product was obtained and a new biologically active metal complex was synthesized. Their structures were identified by characterizing them according to elemental analysis (CHN), thermal analysis, PXRD, conductivity measurements, FT-IR, and UV-vis spectra. Spectral data confirmed the structure of azomethine (-C=N-) and phenolic OH groups with a nitrogen atom of the metal-coordinated ligand and the presence of metal ions. As a result of this information, a tetrahedral geometry was suggested for the Pd(II) complex. Antimicrobial activities of the synthesized metal complex were tested. Pd(II) complex showed the highest cytotoxicity (MIC value 11.25±0.14 µg/mL) effect, comparable to other cis-platinum-based drugs.

The Combination of Aligned PDA‐Fe@PLCL Conduit with Aligned GelMA Hydrogel Promotes Peripheral Nerve Regeneration

AbstractBiomaterial‐assisted therapeutic strategies enable precise modulation to direct endogenous cellular responses and harness regenerative capabilities for nerve repair. However, achieving effective cellular engagement during nerve remodeling remains challenging. Herein, a novel composite nerve guidance conduit (NGC), the GelMA/PLys@PDA‐Fe@PLCL conduit is developed by combining aligned poly(l‐lactide‐co‐caprolactone) (PLCL) nanofibers modified with polydopamine (PDA), ferrous iron (Fe3⁺), and polylysine (PLys) with aligned methacrylate‐anhydride gelatin (GelMA) hydrogel nanofibers. PDA films exhibit strong adhesion and metal coordination properties, allowing Fe3⁺ irons to chelate with phenolic hydroxyl groups of dopamine derivatives, forming a metal‐phenolic network on PLCL. PLys molecules are then grafted onto PDA‐Fe3⁺ coating via Schiff base and Michael addition reactions. This multifunctional coating enhances surface roughness and zeta potential of PLCL nanofibers, imparts superhydrophilicity with anisotropic wetting behavior, and maintains wet tensile properties of substrates. In vitro studies show that the PLys@PDA‐Fe coating significantly promotes aligned distribution of Schwann cells, improves cell adhesion and differentiation, and demonstrates notable antioxidant and anti‐inflammatory properties. When implanted into nerve defects in rats, the multifunctional coating conduit combined with aligned GelMA hydrogel effectively accelerates axonal regeneration, remyelination, and angiogenesis, leading to enhanced motor function recovery. Overall, the GelMA/PLys@PDA‐Fe@PLCL conduit presents a promising strategy for advancing peripheral nerve repair.