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Journal of Inorganic Biochemistry Jun 2024Halogenation of aliphatic C-H bonds is a chemical transformation performed in nature by mononuclear nonheme iron dependent halogenases. The mechanism involves the...
Halogenation of aliphatic C-H bonds is a chemical transformation performed in nature by mononuclear nonheme iron dependent halogenases. The mechanism involves the formation of an iron(IV)-oxo-chloride species that abstracts the hydrogen atom from the reactive C-H bond to form a carbon-centered radical that selectively reacts with the bound chloride ligand, a process commonly referred to as halide rebound. The factors that determine the halide rebound, as opposed to the reaction with the incipient hydroxide ligand, are not clearly understood and examples of well-defined iron(IV)-oxo-halide compounds competent in C-H halogenation are scarce. In this work we have studied the reactivity of three well-defined iron(IV)-oxo complexes containing variants of the tetradentate 1-(2-pyridylmethyl)-1,4,7-triazacyclononane ligand (Pytacn). Interestingly, these compounds exhibit a change in their chemoselectivity towards the functionalization of C-H bonds under certain conditions: their reaction towards C-H bonds in the presence of a halide anionleads to exclusive oxygenation, while the addition of a superacid results in halogenation. Almost quantitative halogenation of ethylbenzene is observed when using the two systems with more sterically congested ligands and even the chlorination of strong C-H bonds such as those of cyclohexane is performed when a methyl group is present in the sixth position of the pyridine ring of the ligand. Mechanistic studies suggest that both reactions, oxygenation and halogenation, proceed through a common rate determining hydrogen atom transfer step and the presence of the acid dictates the fate of the resulting alkyl radical towards preferential halogenation over oxygenation.
PubMed: 38924872
DOI: 10.1016/j.jinorgbio.2024.112643 -
Iranian Journal of Public Health Mar 2024Multiple Myeloma (MM) is a neoplastic hematologic disorder caused by the excessive proliferation of plasma cells and leads to bone lesions, anemia, and kidney failure.... (Review)
Review
Multiple Myeloma (MM) is a neoplastic hematologic disorder caused by the excessive proliferation of plasma cells and leads to bone lesions, anemia, and kidney failure. No definite etiology has been proposed for MM, but several environmental and genetic risk factors have been implicated so far. Exposure to pesticides, benzene, and organic solvents like methyl chloride have been considered a potential risk factor. Asbestos, ionizing radiation, and wood dust exposure have also been associated with MM. As MM is a relatively rare condition, the number of studies is insufficient, and in many studies, only a few study participants recall exposure to any agents. Therefore, establishing a definite risk factor is cumbersome and further studies with large study samples are needed. By recognizing these occupational risk factors, clinicians can encourage employees to reduce their exposure as more as possible and implement precautionary measures. In this review, we highlighted the current research on the potential association between occupational exposures and MM. Because of these studies, new regulations with the goal of occupational exposure reduction are anticipated in the future.
PubMed: 38919290
DOI: 10.18502/ijph.v53i3.15137 -
International Journal of Biological... Jun 2024This work reports about the conjugation of glycine C-terminal ethyl and methyl ester peptides and L-tryptophan methyl ester with sodium hyaluronate in aqueous solutions...
This work reports about the conjugation of glycine C-terminal ethyl and methyl ester peptides and L-tryptophan methyl ester with sodium hyaluronate in aqueous solutions using the peptide coupling agent DMTMM (or short DMT, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride). Detailed infrared (IR) absorbance and H and C (2D) NMR studies (heteronuclear multi-bond correlation spectroscopy, HMBC) confirmed covalent and regioselective amide bonds with the D-glucuronate, but also proves the presence of DMT traces in all conjugates. The ethyl ester`s methyl protons on the peptides` C-terminal could be used to quantify the degree of substitution of the peptide on the hyaluronate scaffold by NMR. The ester group also proved stable during conjugation and work-up, and could in some cases be selectively cleaved in water whilst leaving the amide bond intact as shown by potentiometric charge titration, NMR and IR. The conjugates did not influence the capability of human umbilical vein endothelial cells (HUVECs) to reduce MTS (5-[3-(carboxymethoxy)phenyl]-3-(4,5-dimethyl-2-thiazolyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) to a formazan dye, which points towards a low cytotoxicity for the obtained products. The conjugation method and products could be tested for tissue engineering gels or drug delivery purposes with alternative, biologically active peptides.
PubMed: 38914403
DOI: 10.1016/j.ijbiomac.2024.133301 -
Acta Crystallographica. Section E,... May 2024The reaction of copper(II) oxalate and hexa-methyl-ene-tetra-mine in a deep eutectic solvent made of urea and choline chloride produced crystals of...
The reaction of copper(II) oxalate and hexa-methyl-ene-tetra-mine in a deep eutectic solvent made of urea and choline chloride produced crystals of penta-amine-copper(II) dichloride-urea (1/1), [Cu(NH)]Cl·CO(NH), which was characterized by single-crystal X-ray diffraction. The complex contains discrete penta-amine-copper(II) units in a square-based pyramidal geometry. The overall structure of the multi-component crystal is dictated by hydrogen bonding between urea mol-ecules and amine H atoms with chloride anions.
PubMed: 38845712
DOI: 10.1107/S2056989024004298 -
Archives of Razi Institute Dec 2023Cloves possess antimicrobial and antioxidant activities, among other roles, they can play. This study investigated the effect of clove oil (CLO) on testicular and...
Cloves possess antimicrobial and antioxidant activities, among other roles, they can play. This study investigated the effect of clove oil (CLO) on testicular and epididymal changes induced by cadmium chloride (CdCl). A total of 25 rats were randomly assigned to five groups of five rats. Group A was allowed feed and water . Group B was given 20mg/kg of CdCl, group C was given 20mg/kg of CdCl and 10mg/kg of CLO, group D was given 20mg/kg of CdCl and 20mg/kg of CLO, and group E was given 20mg/kg of CdCl and 20mg/kg of Di Methyl Sulphur Oxide. After the experiment, the animals were sacrificed by cervical dislocation after 24 hours of fasting. The testes and epididymis were harvested, while the right epididymis was homogenized for sperm analysis. The results revealed a significant decrease in progressive motility in group B, while a significant increase was observed in CLO-treated groups (P<0.05). In addition, group B showed a significant reduction in percentage progressive, an increase in percentage non-motile, and a decrease in sperm count. The histological studies showed that the control group displayed normal testicular and epididymal histo-architecture, while the Cadmium group (B) showed a progressive degeneration of the cells and tissues, alleviated by the high dose of CLO in both the testes and epididymis. In conclusion, the current research demonstrated that testicular and epididymal damage induced by Cadmium could decrease fertility, and CLO may be used in alleviating the deleterious effects of CdCl.
Topics: Animals; Male; Epididymis; Rats; Testis; Rats, Wistar; Clove Oil; Cadmium Chloride; Dimethyl Sulfoxide; Random Allocation; Cadmium
PubMed: 38828169
DOI: 10.32592/ARI.2023.78.6.1728 -
Gels (Basel, Switzerland) May 2024Over the years, the concentration of cadmium in soil has increased due to industrialization. Cadmium in the soil enters the human body through plant accumulation,...
Over the years, the concentration of cadmium in soil has increased due to industrialization. Cadmium in the soil enters the human body through plant accumulation, seriously endangering human health. In the current study, two types of hydrogels were successfully synthesized using a free radical polymerization method: an ion-type hydrogel referred to as DMAPAA (-(3-(Dimethyl amino) propyl) acrylamide)/DMAPAAQ (,-Dimethyl amino propyl acrylamide, methyl chloride quaternary) and a non-ion-type hydrogel known as DMAA (,-Dimethylacrylamide). In the experiment carried out in this study, the ion-type hydrogel DMAPAA/DMAPAAQ was introduced to cadmium-contaminated soil for vegetable cultivation. The study found that at cadmium levels of 0 and 2 mg/kg in soil, when exposed to a pH 2 solution, cadmium wasn't detected in the filtrate using ICP. As the amount of cadmium increased to 500 mg/kg, hydrogel addition gradually reduced the filtrate cadmium concentration. Notably, the use of the 4% hydrogel resulted in 0 mg/L of cadmium. For the 0% hydrogel, vegetable cadmium absorption was determined to be 0.07 mg/g, contrasting with 0.03 mg/g for the 4% hydrogel. The DMAPAA/DMAPAAQ hydrogel significantly boosts vegetable growth by efficiently absorbing nitrate ions through ion exchange, releasing them for plant uptake. In contrast, the DMAA hydrogel, used as a control, does not enhance plant growth despite its water absorption properties. In summary, the composite hydrogel shows great potential for enhancing vegetable yield and immobilizing heavy metals in soil.
PubMed: 38786265
DOI: 10.3390/gels10050348 -
Heliyon May 2024Seaweeds have become the focus of experts in recent years due to their biological characteristics and the variety of uses they have for both humans and animals....
Seaweeds have become the focus of experts in recent years due to their biological characteristics and the variety of uses they have for both humans and animals. Biochemical composition, amino acids, fatty acids, and phenolic components were analyzed to explore the nutritive value of , , and from the Bay of Bengal, Bangladesh coast. Proximate composition and mineral content were determined according to the AOAC method. The high-performance liquid chromatography amino acid analysis system was used for the amino acid analysis and the fatty acid profile of the extracted oils was assessed as their methyl esters. The Folin-Ciocalteu technique was used to estimate the phenolic content and the aluminum chloride colorimetric technique was used to calculate the total flavonoid content. The three different species of seaweed had significantly different proximate compositions (P < 0.05), with having the highest protein content. Except for sulfur, the mineral contents were likewise considerably higher (P < 0.05) in . Although the amounts of the essential amino acids were greater than 50 % of the total amino acids in the three studied seaweed species, the total amino acid composition of these three species differed significantly (P < 0.05). The findings indicated that lipid levels were low in all the assessed species, but unsaturated fatty acid levels were high, with exhibiting the highest amounts. The results showed that, compared to the other species, had a substantially higher (P < 0.05) level of total phenolic and flavonoid content. The three studied seaweed appear to be excellent for nutrition based on their overall nutritional profiles. However, due to high protein, unsaturated fatty acid, essential amino acid, and total phenolic and flavonoid content, is the most promising seaweed that will be helpful for pharmaceutical and multifunctional food applications.
PubMed: 38778999
DOI: 10.1016/j.heliyon.2024.e31128 -
Polymers Apr 2024Diacylhydrazine is thermally and chemically stable, and it remains inert to oxygen even at high temperatures. However, it is rapidly oxidized by sodium hypochlorite,...
Diacylhydrazine is thermally and chemically stable, and it remains inert to oxygen even at high temperatures. However, it is rapidly oxidized by sodium hypochlorite, leading to its decomposition into carboxylic acid and nitrogen gas. In the synthesis of a novel poly(diacylhydrazine) as an oxidatively degradable polymer, L-leucine methyl ester is acylated by terephthaloyl chloride. Subsequent hydrazination yields a bishydrazide monomer. The oxidative coupling polymerization of this monomer produces poly(diacylhydrazine). The molecular structures of the products are confirmed by an H NMR analysis. A polymodal molecular weight distribution and a large polydispersity index are observed by GPC in all cases. A 10% weight loss temperature is noted at 286 °C in air by TGA. The obtained polymer is not oxidized by oxygen. No glass transition is observed below the decomposition temperature. Upon the treatment of the poly(diacylhydrazine) with sodium hypochlorite solution, decomposition occurs rapidly, resulting in monomeric carboxylic acid and nitrogen gas. The L-leucine-based poly(diacylhydrazine) serves as a novel on-demand degradable polymer with high levels of thermal and chemical stability during usage.
PubMed: 38732691
DOI: 10.3390/polym16091222 -
Molecules (Basel, Switzerland) May 2024We modified -symmetric benzene-1,3,5--amide (BTA) by introducing flexible linkers in order to generate an N-centered BTA (N-BTA) molecule. The N-BTA compound formed gels...
We modified -symmetric benzene-1,3,5--amide (BTA) by introducing flexible linkers in order to generate an N-centered BTA (N-BTA) molecule. The N-BTA compound formed gels in alcohols and aqueous mixtures of high-polar solvents. Rheological studies showed that the DMSO/water (1:1, /) gels were mechanically stronger compared to other gels, and a similar trend was observed for thermal stability. Powder X-ray analysis of the xerogel obtained from various aqueous gels revealed that the packing modes of the gelators in these systems were similar. The stimuli-responsive properties of the N-BTA towards sodium/potassium salts indicated that the gel network collapsed in the presence of more nucleophilic anions such as cyanide, fluoride, and chloride salts at the MGC, but the gel network was intact when in contact with nitrate, sulphate, acetate, bromide, and iodide salts, indicating the anion-responsive properties of N-BTA gels. Anion-induced gel formation was observed for less nucleophilic anions below the MGC of N-BTA. The ability of N-BTA gels to act as an adsorbent for hazardous anionic and cationic dyes in water was evaluated. The results indicated that the ethanolic gels of N-BTA successfully absorbed methylene blue and methyl orange dyes from water. This work demonstrates the potential of the N-BTA gelator to act as a stimuli-responsive material and a promising candidate for water purification.
PubMed: 38731640
DOI: 10.3390/molecules29092149 -
Scientific Reports May 2024The results revealed the significant effect of NaCl, KCl, CaCl, MgCl, CaSO, MgSO, and NaSO and pH values of 3.5-11 on the interfacial tension (IFT) reduction using three...
The results revealed the significant effect of NaCl, KCl, CaCl, MgCl, CaSO, MgSO, and NaSO and pH values of 3.5-11 on the interfacial tension (IFT) reduction using three types of neutral, acidic, and basic crude oils, especially for acidic crude oil (crude oil II) as the pH was changed from 3.5 to 11 (due to saponification process). The findings showed the highest impact of pH on the IFT of crude oil II with a reducing trend, especially for the pH 11 when no salts exist. The results revealed that the salts except MgCl and CaCl led to a similar IFT variation trend for the case of distilled water/crude oil II. For the MgCl and CaCl solutions, a shifting point for IFT values was inevitable. Besides, the dissolution of 1-dodecyl-3-methyl imidazolium chloride ([Cmim][Cl]) with a concentration of 100-1000 ppm eliminates the effect of pH on IFT which leads to a reducing trend for all the examined crude oils with minimum IFT of 0.08 mN/m. Finally, the [Cmim][Cl] adsorption (under pH values) for crude oils using only NaSO was measured and the minimum adsorption of 0.41 mg surfactant/g Rock under the light of saponification process was obtained.
PubMed: 38729971
DOI: 10.1038/s41598-024-58458-0