Metal Ion Chelating Research Articles

DL‐malic acid for inhibiting the re‐ignition of long‐flame coal and its micro‐reaction mechanism

AbstractTo study the metal ion chelating agent (DL‐malic acid) inhibiting oxidation characteristics of residual coal in goaf, the microscopic thermal transformation characteristics of the treated coal samples were obtained using apparent morphology, infrared spectroscopy, free radical testing, and thermal analysis. The results demonstrate that after the addition of malic acid, the sphericity and roundness of the coal samples decrease, and the small fractured particles accumulate in the pores of the oxidized coal samples and, thereby, reduce the number of coal–oxygen contact sites. The addition of 10% malic acid promotes the conversion of functional groups (FG) and free radicals in pre‐oxidized coal, inhibits the catalytic effect of metal ions, generates more active sites, and increases the total heat release during the combustion process. There are strong endothermic points in the malic acid‐treated coal samples, and the free water evaporation blocked by small particles in the holes delays the initial heat release temperature of the coal samples. Pre‐oxidation can promote changes in the valence state of metal ions in coal, increase the adhesion between broken pre‐oxidized coal particles via malic acid chelation, and lose the catalytic effect of metal ions; this inhibits the process of oxidative re‐ignition of coal samples.

Dual-use of sodium alginate to prepare sodium algenate -derived carbon dots sodium algenate hydrogel composite for Pb2+ removal

The effective mitigation of the environmental impact of heavy metal remains a significant scientific challenge. In this study, a novel and environmentally friendly approach has been proposed to fabricate three-dimensional (3D) functional composite materials for Pb(II) removal. The easy-to-recycle spherical adsorbent is prepared by the dual utilization of sodium alginate (SA) as a bio-source precursor for the synthesis of carbon dots (CDs) and as a natural framework for the formation of SA hydrogel. The abundant surface-active groups on the SA hydrogel not only provide additional adsorption sites for the aggregation of heavy metal ions but can also be readily cross-linked with CDs without chemical additives, and thereby offering a 3D porous structure for chelating metal ions. The resulting HL-5CDs adsorbent demonstrates an impressive adsorption capacity of 305.21 mg·g−1 for Pb(II). The adsorption mechanism involves both chemical reaction and diffusion, leveraging the porous structure and rich oxygen groups of the material. Notably, a pot experiment revealed that the as-prepared HL-5CDs could inhibit the bioavailability of Pb(II). This study introduces a green and straightforward method for creating high-performance adsorbents, showcasing potential applications in energy, cleaning, and the remediation of wastewater pollution.

Deactivation of porphyrin metal-organic framework in advanced oxidation process: Photobleaching and underlying mechanism

Porphyrin metal-organic frameworks (MOFs) are widely used in photocatalytic advanced oxidation processes (AOP). However, the stability and deactivation of MOFs, crucial for reusability, have been understudied compared to their catalytic activity. We investigated photobleaching in porphyrin MOFs PCN-224-M (M= H2, Fe, Co, Cu, Zn) under visible light and H2O2. The MOFs exhibited crystallinity loss, ring-opening cleavage, and linker degradation. Photobleaching resulted from direct redox reactions between porphyrin sites and H2O2. Metal-oxo-porphyrin intermediates played a key role in the "group effect," with different functional groups affecting the photobleaching rate: PCN-224-Fe ≈ PCN-224-Co > PCN-224-H2 > PCN-224-Cu ≈ PCN-224-Zn. This trend related to chelated metal ions' electronic structures and their propensity for metal-oxo intermediate formation, establishing a structure-stability relationship. Our study enhances understanding of deactivation mechanisms in porphyrin MOFs during AOP, aiding the design of resilient and efficient MOF catalysts for environmental applications.

Melanin-Inspired Composite Materials: From Nanoarchitectonics to Applications.

Synthetic melanin is a mimic of natural melanin analogue with intriguing properties such as metal-ion chelation, redox activity, adhesion, and broadband absorption. Melanin-inspired composite materials are formulated by assembly of melanin with other types of inorganic and organic components to target, combine, and build up the functionality, far beyond their natural capabilities. Developing efficient and universal methodologies to prepare melanin-based composite materials with unique functionality is vital for their further applications. In this review, we summarize three types of synthetic approaches, predoping, surface engineering, and physical blending, to access various melanin-inspired composite materials with distinctive structure and properties. The applications of melanin-inspired composite materials in free radical scavenging, bioimaging, antifouling, and catalytic applications are also reviewed. This review also concludes current challenges that must be addressed and research opportunities in future studies.

Bioinspired phosphorus-free and halogen-free biomass coatings for durable flame retardant modification of regenerated cellulose fibers

Inspired by mussel adhesion and intrinsic flame retardant alginate fibers, a biomass flame retardant (PPCA) containing adhesive catechol and sodium carboxylate structure (-COO−Na+) based on biomass amino acids and protocatechualdehyde was designed to prepare flame retardant Lyocell fibers (Lyocell@PPCA@Na). Furthermore, through the substitution and chelation of metal ions by PPCA in the cellulose molecular chain, flame retardant Lyocell fibers chelating copper and iron ions (Lyocell@PPCA@Cu, Lyocell@PPCA@Fe) were prepared. Compared with the original sample, the peak heat release rate (PHRR) and total heat release (THR) for modified Lyocell fibers were significantly reduced. In addition, the modified sample exhibited a certain flame retardant durability. TG-FTIR analysis showed that the release of flammable gaseous substances was inhibited. The introduction of Schiff bases and aromatic structures in PPCA, as well as the decomposition of carboxylic metal salts were beneficial for the formation of char residue containing metal carbonates and metal oxides to play the condensed phase flame retardant effect. This work develops a new idea for the preparation of eco-friendly flame retardant Lyocell fibers without the traditional flame retardant elements such as P, Cl, and Br.

Antioxidant and antibrowning properties of Maillard reaction products in food and biological systems.

Oxidative damage refers to the harm caused to biological systems by reactive oxygen species such as free radicals. This damage can contribute to a range of diseases and aging processes in organisms. Moreover, oxidative deterioration of lipids is a serious problem because it reduces the shelf life of food products, degrades their nutritional value, and produces reaction products that could be toxic. Antioxidants are effective compounds for preventing lipid oxidation, and synthetic antioxidants are frequently added to foods due to their high effectiveness and low cost. However, the safety of these antioxidants is a subject that is being discussed in the public more and more. Synthetic antioxidants have been found to have potential negative effects on health due to their ability to accumulate in tissues and disrupt natural antioxidant systems. During thermal processing and storage, foods containing reducing sugars and amino compounds frequently produce Maillard reaction products (MRPs). Through the chelation of metal ions, scavenging of reactive oxygen species, destruction of hydrogen peroxide, and suppression of radical chain reaction, MRPs exhibit excellent antioxidant properties in a variety of food products and biological systems. Also, the capacity of MRPs to chelate metals makes them as a potential inhibitor of the enzymatic browning in fruits and vegetables. In this book chapter, the methods used for the evaluation of antioxidant activity of MRPs are provided. Moreover, the antioxidant and antibrowning activities of MRPs in food and biological systems is discussed. MRPs can generally be isolated and used as commercial preparations of natural antioxidants.

Exploration of secondary metabolites from green algae as antimicrobial agents: A comprehensive review

A number of advancements have been made in algal technology in different fields, such as medical, cosmetic, and pharmaceutical. Green algae (Chlorophyta) are a group of photosynthetic organisms which live in both aquatic and terrestrial environments. They are a potential source of bioactive compounds for the treatment and prevention of a wide range of infectious diseases caused by microorganisms. These compounds also possess anti-inflammatory, antioxidant, anticoagulant, antitumor, and immunomodulatory properties. A wide variety of bioactive compounds are produced, including polysaccharides, which exhibit antimicrobial properties capable of interfering with the cell walls, membranes, and nucleic acids of microorganisms. Membrane fluidity, permeability, or integrity can be affected by polyphenols and fatty acids which scavenge free radicals, chelate metal ions, or disrupt enzymes and membranes. Proteins and peptides form pores within the membranes which bind to specific receptors or inhibit enzymes. Adaptation to adverse environmental conditions, such as temperature extremes, photooxidation, salinity, or osmotic stress, results in the formation of bioactive compounds by altering the physiological and biochemical pathways of algae for the maintenance of cellular homeostasis. With changing consumer preferences and an increase in the number of resistant microorganisms, it is critical to seek novel antimicrobial compounds from green algae. The search for novel bioactive compounds with antimicrobial properties from green algae may serve as an alternative in the light of increased drug resistance in microorganisms. However, in vitro and in vivo evaluations of the safety, efficacy, and mechanism of action of the antimicrobial compounds from green algae require more research. Providing an overview of previous endeavours in this emerging field, this review provides perspectives and a summary of the bioactive compounds responsible for the antimicrobial properties of green algal extracts.

Multiple control of azoquinoline based molecular photoswitches.

Multi-addressable molecular switches with high sophistication are creating intensive interest, but are challenging to control. Herein, we incorporated ring-chain dynamic covalent sites into azoquinoline scaffolds for the construction of multi-responsive and multi-state switching systems. The manipulation of ring-chain equilibrium by acid/base and dynamic covalent reactions with primary/secondary amines allowed the regulation of E/Z photoisomerization. Moreover, the carboxyl and quinoline motifs provided recognition handles for the chelation of metal ions and turning off photoswitching, with otherwise inaccessible Z-isomer complexes obtained via the change of stimulation sequence. Particularly, the distinct metal binding behaviors of primary amine and secondary amine products offered a facile way for modulating E/Z switching and dynamic covalent reactivity. As a result, multiple control of azoarene photoswitches was accomplished, including light, pH, metal ions, and amine nucleophiles, with interplay between diverse stimuli further enabling addressable multi-state switching within reaction networks. The underlying structural and mechanistic insights were elucidated, paving the way for the creation of complex switching systems, molecular assemblies, and intelligent materials.

Synthesis and evaluation of butylphthalide-scutellarein hybrids as multifunctional agents for the treatment of Alzheimer's disease

A series of butylphthalide and scutellarein hybrids 3-(alkyl/alkenyl) hydroxyphthalide derivatives were designed, synthesized and evaluated as multifunctional agents against Alzheimer's disease. In vitro bioactivity assays indicated that most of the compounds displayed excellent antioxidant activity and moderate to good inhibition activities of self-induced Aβ1-42 aggregation. Among them, compound 7c was demonstrated as a potential and balanced multifunctional candidate displaying the best inhibitory effects on self- and Cu2+-induced Aβ1–42 aggregation (90.2 % and 35.4 %, respectively) and moderate activity for disaggregation of Aβ1-42 aggregation (42.5 %). In addition, 7c also displayed excellent antioxidant (2.42 Trolox equivalents), metal ions chelating, oxidative stress alleviation, neuroprotective and anti-neuroinflammatory activities. Furthermore, in vivo study demonstrated that 7c could ameliorate the learning and memory impairment induced by sodium nitrite and Aβ1-42 in the step-down passive avoidance test. These balanced multifunctional profiles supporting compound 7c as a novel potential candidate for the treatment of AD.

A new metal ion chelator attenuates human tau accumulation-induced neurodegeneration and memory deficits in mice

Neuronal neurofibrillary tangles containing Tau hyperphosphorylation proteins are a typical pathological marker of Alzheimer's disease (AD). The level of tangles in neurons correlates positively with severe dementia. However, how Tau induces cognitive dysfunction is still unknown, which leads to a lack of effective treatments for AD. Metal ions deposition occurs with tangles in AD brain autopsy. Reduced metal ion can improve the pathology of AD. To explore whether abnormally phosphorylated Tau causes metal ion deposition, we overexpressed human full-length Tau (hTau) in the hippocampal CA3 area of mice and primary cultured hippocampal neurons (CPHN) and found that Tau accumulation induced iron deposition and activated calcineurin (CaN), which dephosphorylates glycogen synthase kinase 3 beta (GSK3β), mediating Tau hyperphosphorylation. Simultaneous activation of CaN dephosphorylates cyclic-AMP response binding protein (CREB), leading to synaptic deficits and memory impairment, as shown in our previous study; this seems to be a vicious cycle exacerbating tauopathy. In the current study, we developed a new metal ion chelator that displayed a significant inhibitory effect on Tau phosphorylation and memory impairment by chelating iron ions in vivo and in vitro. These findings provide new insight into the mechanism of memory impairment induced by Tau accumulation and develop a novel potential treatment for tauopathy in AD.

Extraction and determination of trace Pb(II) and Cd(II) from food and water samples using phosphorylated ceramic column

The consumption of water and food contaminated with potentially toxic metals causes serious health issues. It is beneficial to analyze the level of contamination of such water and food resources before supply for household utility. Here, we electrochemically prepared a porous aluminum oxide (AO) disk and studied for the micro-extraction analysis of Pb(II) and Cd(II) ions in food and water samples. The phosphorylated AO disk was characterized by SEM, EDX and XPS analysis for structural and functional group studies. The phosphorylation significantly increases the chelation of metal ions and enhances the hydrophilicity, leading to significantly shorter analysis time. The prepared material interestingly reduces the spectral interferences by sample cleanup and significantly increases the analyte concentration. Several experimental variables were optimized and the method shows a good detection limit of 0.02 ng mL−1 with RSD 3.52%. The enrichment factor for real samples was found to be 66.6. The presence of co-existing does not much affected and a good tolerance level for other co-existing ions was found for Pb(II) and Cd(II) analyses. The proposed method was validated for its accuracy by standard addition method and by analyzing certified reference materials (NIES 10c and SRM 1572b). The obtained results at 95% confidence level using the Student's t test, are below the critical Student's t value of 4.303, confirming the reliability of procedure. Furthermore, the method shows good precision, with RSD less than 5% for subsequent replicate measurements, reaffirming the consistency and robustness of the method.

Molecular dynamics, molecular docking, DFT, and ADMET investigations of the Co(II), Cu(II), and Zn(II) chelating on the antioxidant activity and SARS-CoV-2 main protease inhibition of quercetin

The natural flavonol quercetin (Q) is found in many vegetables, fruits, and beverages, and it is known as a strong antioxidant. Its metal ion chelation may increase its antioxidant activity. The present study aims to explore the Co(II), Cu(II), and Zn(II) chelating on the antioxidant effectiveness and severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) main protease (Mpro) inhibitory of quercetin using Density-functional theory (DFT), molecular docking, and molecular dynamics simulations (MD). DFT calculations at the B3LYP/LanL2DZ reveal that the high antioxidant activity of the metal-chelated quercetin complexes is mainly returned to their lower ionization potentials (IPs) compared with the one of the free quercetin. Molecular docking of quercetin and its Co(II), Cu(II), and Zn(II) chelates into the active binding sites of peroxiredoxin 5 and SARS-CoV-2 main protease (Mpro) were performed using Lamarckian Genetic Algorithm method. The docked quercetin and its metal chelates fit well into the binding site of the target proteins, and their binding affinity is strongly influenced by the type of the chelated metals Co(II), Cu(II), and Zn(II), and molar ratio metal: ligand, i.e. 1:2 and 2:1. Further, the binding stability of QZn2 and QCu2 in peroxiredoxin 5 and SARS-CoV-2 main protease targets is evaluated using MD simulation conducted for 100 ns simulations at natural room temperature conditions, and the obtained results showed that all chelates remain bound to the ligand binding groove of protein except for 1HD2_QZn2 complex. Finally, the adsorption, distribution, metabolism, excretion, and toxicity (ADMET) and drug-likeness properties of quercetin and cobalt(II)-quercetin (QCo2(II)) were investigated. Communicated by Ramaswamy H. Sarma

Synthesis and application of EDTA grafed metal-organic frameworks (MOFs) and graphene composite for the electrochemical detection of lead(II)

ABSTRACTThe rapid and sensitive detection of heavy metal ion concentrations in water holds significant importance for water resource quality control and protection. In this study, we developed a novel electrochemical sensor utilising a composite material consisting of ethylene diamine tetraacetic acid (EDTA) grafted metal-organic frameworks (MOFs NH2-UiO-66) and graphene to detect Pb2+ in water. The NH2-UiO-66 material exhibited a large specific surface area and porous structure, which was advantageous for the pre-enrichment of the heavy meatal ions. EDTA contained abundant – COOH groups, enabling it to chelate metal ions and increase the reaction sites of redox reactions. The introduction of graphene improved the conductivity of the composite, facilitating electron transfer and enhancing the sensitivity of the electrochemical sensor. Under optimal conditions, the linear range for Pb2+ detection was 0.1 μM–50 μM, and the limit of detection was achieved at 0.052 μM. Furthermore, simultaneous detection of Pb2+ and Cd2+ was successfully accomplished. The fabricated sensor also exhibited excellent selectivity, reproducibility and stability.

Protection of navy-bean bioactive peptides within nanoliposomes: morphological, structural and biological changes

This study aimed to produce bioactive peptides from navy-bean protein with alcalase and pepsin enzymes (30–300 min) and to load them into a nanoliposome system to stabilize and improve their bioavailability. The degree of hydrolysis and biological activities (scavenging of DPPH, OH, and ABTS free radicals, reducing power, and chelating metal ions) of navy-bean protein were affected by the type of enzyme and hydrolysis time. The average particle size (83–116 nm), PDI (0.23–0.39), zeta potential (− 13 to − 20 mV), and encapsulation efficiency (80–91%) of nanoliposomes were influenced by the type and charge of peptides. The storage temperature and the type of loaded peptide greatly affected the physical stability of nanocarriers and maintaining EE during storage. The FTIR results suggested the effect of enzymatic hydrolysis on the secondary structures of protein and the effective placement of peptides inside polar-regions and the phospholipid monolayer membrane. SEM images showed relatively uniform-sized particles with irregular structures, which confirmed the results of DLS. The antioxidant activity of primary peptides affected the free radical scavenging of loaded nanoliposomes. Liposomes loaded with navy-bean peptides can be used as a health-giving formula in enriching all kinds of drinks, desserts, confectionery products, etc.Graphical

Amadori compounds (N-(1-Deoxy-D-fructos-1-yl)-amino acid): The natural transition metal ions (Cu2+, Fe2+, Zn2+) chelators formed during food processing

The Maillard initial products, Amadori compounds (N-(1-Deoxy-D-fructos-1-yl)-amino acid), are considered as the beneficial component with various physiological functions. This study systematically demonstrated that 12 Amadori compounds have effective chelating effect of Cu2+, Fe2+ and Zn2+, and the chelating effect of Cu2+ and Fe2+ is better than that of Zn2+. The chelating strength of Amadori compounds is positively correlated with their concentration. Among them, N-(1-Deoxy-D-fructos-1-yl)-histidine (Fru-His) has the strongest chelating ability. UV spectrum and SEM demonstrated the formation of chelates and the change of surface structure after the chelation reaction. In addition, Amadori compounds have obvious inhibitory effect on the formation of oxidative free radicals caused by metal ions, which can effectively inhibit the oxidative damage of DNA caused by Cu2+ ion and Fenton reaction caused by Fe2+ ion, and reduce Fe3+ ion. Therefore, the Amadori compounds can be applied as a potent metal ion chelator in the development of functional foods.

Bifunctional backbone modified squaramide dipeptides as amyloid beta (Aβ) aggregation inhibitors

Alzheimer's disease (AD) is a devastating neurodegenerative condition with complex pathophysiology. Aggregated amyloid beta (Aβ) peptide plaques and higher concentrations of bio-metals such as copper (Cu), zinc (Zn), and iron (Fe) are the most significant hallmarks of AD observed in the brains of AD patients. Therefore simultaneous inhibition of Aβ peptide aggregation and reduction of metal stress may serve as an effective therapeutic approach for treating Alzheimer's disease. A series of bifunctional dipeptides bearing squaramide backbone were synthesized and investigated for their ability to chelate metal ions and prevent Aβ peptide aggregation. Dipeptides with Valine (V) and Threonine (T) substitutions at the C-terminus exhibited preferential chelation with Cu(II), Zn(II), and Fe(III) metal ions in the presence of other metal ions. They were also found to inhibit the aggregation of Aβ peptide in-vitro. A further molecular dynamics (MD) simulation study demonstrated that these two dipeptides interact with the Aβ peptide in the hydrophobic core (KLVFF) region. Circular dichroism (CD) study revealed slight conformational change in the Aβ peptide upon the interactions with dipeptides. Apart from metal chelation and inhibition of Aβ peptide aggregation, the selected dipeptides were found to possess anti-oxidant properties. Therefore, the squaramide backbone-modified dipeptides may serve as an active bifunctional scaffold towards the development of new chemical entities for the treatment of Alzheimer's disease.

A poly-histidine motif of HOXA1 is involved in regulatory interactions with cysteine-rich proteins

Homopolymeric amino acid repeats are found in about 24 % of human proteins and are over-represented in transcriptions factors and kinases. Although relatively rare, homopolymeric histidine repeats (polyH) are more significantly found in proteins involved in the regulation of embryonic development. To gain a better understanding of the role of polyH in these proteins, we used a bioinformatic approach to search for shared features in the interactomes of polyH-containing proteins in human. Our analysis revealed that polyH protein interactomes are enriched in cysteine-rich proteins and in proteins containing (a) cysteine repeat(s). Focusing on HOXA1, a HOX transcription factor displaying one long polyH motif, we identified that the polyH motif is required for the HOXA1 interaction with such cysteine-rich proteins. We observed a correlation between the length of the polyH repeat and the strength of the HOXA1 interaction with one Cys-rich protein, MDFI. We also found that metal ion chelators disrupt the HOXA1-MDFI interaction supporting that such metal ions are required for the interaction. Furthermore, we identified three polyH interactors which down-regulate the transcriptional activity of HOXA1. Taken together, our data point towards the involvement of polyH and cysteines in regulatory interactions between proteins, notably transcription factors like HOXA1.

A comprehensive evaluation of the effect of key parameters on the performance of DTPA chelating agent in modifying sandstone surface charge

Despite the positive aspects of low salinity water (LSW), this technique is relatively expensive and unavailable in some countries. Furthermore, potential problems associated with LSW such as scale precipitation in carbonate reservoirs and fine migration in sandstone reservoirs raise concerns. Chelating agents have the ability to chelate metal ions from solution, effectively reducing the salinity of seawater (SW) and mimicking the behavior of LSW. However, they mitigate the challenges associated with LSW injection. This study focuses on how the Diethylenetriaminepentaacetic acid (DTPA) chelating agent performs in modifying rock surface charge. The impact of concentration, brine salinity, potential determining ions (PDIs), oil presence, Fe3+ ions, and solution pH on the effectiveness of DTPA in altering rock surface charge was evaluated. Furthermore, wettability alteration and sand pack flooding tests were conducted to study the effect of DTPA on rock wettability and oil recovery. Results of wettability alteration, zeta potential, sand pack flooding experiments and ion concentration analysis are reported in this paper. The results showed that reducing salinity, increasing DTPA concentration, and raising solution pH changed rock wettability from oil-wetness towards water-wetness. The presence or absence of PDIs in the solution did not affect the performance of DTPA. However, by tripling the concentration of these ions in the solution, the performance of DTPA in changing rock surface charge was impaired. Based on the wettability alteration and zeta potential experiments, 5 wt% DTPA was determined as the optimum concentration. Subsequent flooding experiments revealed that injecting 5 wt% DTPA chelating agents into the sandstone sand pack after SW injection increased oil recovery from 48 % to 68.3 %. The analysis of ion concentrations also revealed a significant increase in the amount of calcium ions during the DTPA flooding, indicating the chelation of metal ions from both rock and solution and improving the wettability conditions.

Preparation of mussel-inspired polydopamine-functionalized TEMPO-oxidized cellulose nanofiber-based composite aerogel as reusable adsorbent for water treatment

Water pollution is an ongoing trouble that is of significant urgency to resolve worldwide. However, traditional materials used in the process of water purification are costly and energy intensive. The preparation of low-cost, green and sustainable aerogels with low density, high porosity and high specific surface area (SSA) is a great challenge. In this paper, a mussel-inspired, low-cost, polydopamine (PDA)-functionalized TEMPO-oxidized cellulose nanofiber (TOCNF) PDA/TOCNF composite aerogel has been rationally designed and fabricated with low-density, high porosity and high SSA. The PDA/TOCNF composite aerogel shows low density (18.2 mg/cm3), high porosity (98.7 %), and large surface areas (41.3 m2/g). The resulting PDA/TOCNF composite aerogel could adsorb a maximum of 314.6 mg/g of methylene blue (MB). The recycle experiment for reusing of adsorbent showed that after five consecutive cycles, the removal ability of MB by the PDA/TOCNF composite aerogel still maintained higher than 90 %. In addition, the PDA/TOCNF composite aerogel also had a high adsorption capacity of heavy metal ions, for example, it adsorbs 446.0 mg/g of Cu2+, 222.0 mg/g of Pb2+, 267.0 mg/g of Cd2+, and 600.0 mg/g of Fe3+, respectively. The possible adsorption mechanisms imply that the PDA/TOCNF composite aerogel adsorbs MB due to the synergistic binding interactions, such as electrostatic attraction, π-π stacking interaction, Vander waals force, and hydrogen bonding. Similarly, the PDA/TOCNF composite aerogel adsorbs metal ions due to the electrostatic attraction and chelation of metal ions with the PDA/TOCNF aerogel. Therefore, PDA/TOCNF composite aerogels may have potential applications in wastewater treatment because of their sustainability and low energy consumption.

Antioxidant, Antimicrobial and Spectroscopic Discussion of Guanine Azo Ligand with Cu(II) and Ag (I) Complexes

In this paper, we have provided a very thorough analysis of a new novel chelate metal ion complex of [Cu(II),Ag(I)] prepared via the interaction with the ligand{ 2-amino-8-((4-chloro-3-hydroxyphenyl) diazenyl)azo]guanine} [LAAG], which is synthesized by diazo coupling of the 5-amino-2-chlorophenol with amino acid guanine. The ligand and its complexes are identified by a variety of techniques, like [HNMR, FTIR, and Uv-vis] spectral, thermal analysis (TGA), and element analyses (CHN). The molar ratio was achieved so that the Cu(II) complex has (1:2) (M:L) with octahedral geometry; however, the Ag(I) complex has (1:1) (M:L) with tetrahedral geometry, and the ligand acts as neutral N,N-bidentate; as well as the ligand (LAAG) and its complexes were assessed against the two types of bacteria (Klebsiella pneumonia, Staphylococcus aureus,antifungal (Candida), and antioxidant This study showed that all compounds (the ligand and its complexes) had antimicrobial activity and more biological activity.