Use Of Thiourea Research Articles

Thiourea and arginine synergistically preserve redox homeostasis and ionic balance for alleviating salinity stress in wheat

Plant growth regulators are cost-effective and efficient methods for enhancing plant defenses under stress conditions. This study investigates the ability of two plant growth-regulating substances, thiourea (TU) and arginine (Arg), to mitigate salinity stress in wheat. The results show that both TU and Arg, particularly when used together, modify plant growth under salinity stress. Their application significantly increases the activities of antioxidant enzymes while decreasing the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and relative electrolyte leakage (REL) in wheat seedlings. Additionally, these treatments significantly reduce the concentrations of Na+ and Ca2+ and the Na+/K+ ratio, while significantly increasing K+ levels, thereby preserving ionic osmotic balance. Importantly, TU and Arg markedly enhance the chlorophyll content, net photosynthetic rate, and gas exchange rate in wheat seedlings under salinity stress. The use of TU and Arg, either individually or in combination, results in a 9.03–47.45% increase in dry matter accumulation, with the maximum increase observed when both are used together. Overall, this study highlights that maintaining redox homeostasis and ionic balance are crucial for enhancing plant tolerance to salinity stress. Furthermore, TU and Arg are recommended as potential plant growth regulators to boost wheat productivity under such conditions, especially when applied together.

Energy-efficient electrochemical recovery of gold enabled by a thiourea-based electrolyte system

The application of non-cyanide baths in electroplating for gold recovery has drawn significant attention due to their clear benefits on the environment and human health. Among these alternatives, thiourea has emerged as a promising non-cyanide bath, and yet high energy and reagent consumption has impeded its widespread adoption. Herein, an energy-efficient gold recovery process via electroplating was developed to reduce bath depletion. The redox potentials of gold deposition using thiourea electrolyte were examined through linear sweep voltammetry, and the consumed energy during the electrochemical plating of gold was quantified. The gold deposition was achieved in the two-electrode system enabling a 97% recovery under 0.3 V of the cell voltage. The proposed system exhibited a significant reduction in energy consumption to 0.129 kWh∙kg−1, implying that the oxidation of free thiourea on the anode mainly contributed to the decrease in the applied voltage and energy. Furthermore, the suppression of the bath consumption was evaluated compared with electroless plating, another reliable deposition process, throughout monitoring gold desorption and deposition efficiencies during the cyclic use of thiourea. The retardation of the sorbent consumption was observed in the electroplating during the consecutive cycles, which inferred that the reduction of its oxidized form, formamidine disulfide, led to the regeneration of the agent on the cathode. Thus, the suggested electroplating process with a gold-thiourea bath shows great potential as a workable means of gold recovery from an economic standpoint with its low energy and sorbent consumption to realize the commercialization of urban mining in the electronic industry.

The Origin of Antithyroid Drugs.

Background: When the antithyroid drugs were discovered in the early 1940s, they were immediately recognized as a revolutionary new treatment for hyperthyroidism. Although much has been learned about their mechanism of action and clinical utility, they continue to be used today in much the same way as they have been since their introduction. Summary: In 1995, Dr. Clark Sawin gave an address on the history of antithyroid drug development at the 11th International Thyroid Congress in Toronto, Ontario, Canada. In his review, Dr. Sawin recounted the original observations by Drs. Julia and Cosmo Mackenzie and Curt Richter at the Johns Hopkins University School of Medicine, and how their work ultimately led to Dr. Edwin (Ted) B. Astwood's seminal 1943 report on the use of thiourea and thiouracil in the Journal of the American Medical Association. He also described the development of propylthiouracil and methimazole as less toxic alternatives. He concluded his remarks by noting the often-serendipitous pathway of drug development and the role of pharmaceutical companies in the process. Conclusions: Antithyroid drugs remain a cornerstone of thyroid therapeutics. It is informative to review the process by which they came into use, as this is a seminal part of the history of thyroid disease in the 20th century. This knowledge may also spark additional research leading to new pharmacotherapies for patients with hyperthyroidism.

Prospects for thiourea as a leaching agent in Colombian gold small-scale mining: A comprehensive review

Thiourea, as an alternative medium, is one of the most promising leaching agents for gold recovery by its commercial benefits and research challenges associated with performance and environmental impacts. This review article describes the operational conditions for the use of Thiourea vs cyanide, its chemistry, limitations, toxicity factors, environment, and recovery processes. Although thiourea gold extraction processes have not been applied on a large scale due to the instability of the reagent, its potential to overcome the limitations of cyanide is attractive to the process; with pH, potential, oxidant dosage, and temperature control, solubilized gold thiourea species are achieved. These can be recovered from the pregnant leach solution through methods such as activated carbon absorption and adsorption, polyurethane foams, ion exchange, and electrodeposition.

Membrane electrolysis for recovering Sb and Bi from elution solutions of ion-exchange resins used in copper electrorefining: A cyclic voltammetric study

• A membrane electrolysis system was proposed to recover Sb-Bi from HCl solution. • The effects of several parameters on the process were studied by cyclic voltammetry. • The reactions of electrodeposition of Sb-Bi are not electrochemically reversible. • The diffusion control for Bi is greater than for Sb. • The use of thiourea as a complexing agent must be avoided. Antimony (Sb) and bismuth (Bi), which have been considered critical raw materials by the European Commission, cause inconveniences to copper production when they are present as impurities in copper electrorefining solutions. Therefore, ion-exchange resins to extract Sb and Bi from copper-containing electrolytes have typically been applied; after the adsorption of the metals, the elution step is conducted with an HCl solution to desorb them. In the present study, a novel membrane electrolysis system with a cation-exchange membrane was proposed to extract Sb and Bi ions from the elution solution, and a cyclic voltammetric study was carried out to evaluate the influence of the most important operating parameters on the process performance, such as Sb, Bi and HCl concentration, dilution factor of the solution, the presence of thiourea as a complexing agent, the presence of iron as an impurity, and temperature. The obtained voltammograms indicated that the simultaneous presence of the metals in solution alters considerably their electrodeposition and oxidation pattern when compared to the solutions with pure metals. The reactions of electrodeposition of both metals are not electrochemically reversible and the diffusion control for bismuth is greater than that for antimony. The increase in the concentration of Sb affects its electrodeposition kinetically, whereas that of Bi is affected both kinetically and thermodynamically. The increase in HCl concentration disfavors the electrodeposition of both metals. Diluting the solution reduces the energy consumption and prolongs the membrane lifespan. Increasing the temperature reduces the cathodic potential to deposit the metals but favors the hydrogen evolution reaction. The presence of iron as an impurity does not affect the electrodeposition of both metals, whereas the use of thiourea as a complexing agent must be avoided because it impairs their electrodeposition.

Microwave treatment for gold minerals used in small-scale mining

Gold mining in Colombia has produced wealth that has helped the social and economic development of the country. Studying its extraction process offers artisanal mining broad alternatives that are more profitable for its small-scale production. Through this research, the possibility is offered of extracting 93.10% of gold in 180 minutes from a refractory mineral of pyritic origin with economic and environmentally friendly techniques such as the use of pretreatment with microwave waves, exposing the mineral to 637ºC for a maximum time of 4 minutes, and the use of thiourea as leaching agent at concentrations of 0.1 M. When comparing gold extraction with thiourea without pretreatment, a low extraction percentage is shown, 19.98%. This microwave pretreatment process was carried out on a nickeliferous laterite mineral, however, the results were not as effective for the extraction of nickel, only 40.8% was obtained in 420 minutes, because the pretreatment with its exposure Microwaving was not efficient.

Facile One Pot Synthesis of Thiocarbamoyl Chitosan for the Adsorptive Elimination of Hexavalent Cr (VI) Ions

The industrial effluents include heavy metals such as Cr, Pb, Hg,Cu, Ni etc. which are affecting ecosystem and have harmful effects on mankind. Biopolymers like chitosan have been extensively applied for waste water treatment. Use of thio urea and glutaraldehyde to make thiocarbamoyl chitosan was investigated for removal of chromium ion from aqueous solution. TC-CS was characterized by various spectrometric techniques such as FTIR, SEM, EDX, BET and pHzpc. It was observed that 94% of metal ions have been removed within the first 2 hrs after contact with bio-sorbent. The adsorption study indicates that the removal rate of Cr (VI) ions from aqueous solution by TC-CS sorbent was excellent and up to 1.06 mmol/gm (56.18 mg/gm). The removal efficiency was dependent on solution-pH, contact time, adsorbent dose and initial metal concentration. The highest adsorption was found at pH 6 at 100 mg of adsorbent. Adsorption kinetics data followed pseudo second order kinetic model with linear coefficient of 0.9997. The adsorption process could be described well by Langmuir isotherm (R2=0.9860) suggesting favourable adsorption through homogeneous monolayer adsorption.

Alleviation of drought stress by root-applied thiourea is related to elevated photosynthetic pigments, osmoprotectants, antioxidant enzymes, and tubers yield and suppressed oxidative stress in potatoes cultivars.

The growth and productivity of plants are enhanced by the use of thiourea (TU) under stressful conditions. When TU is applied as a rooting medium, it improves plant growth characteristics and other physiological parameters in stressed environment. A pot experiment was conducted in the botanical garden of the Government College University, Faisalabad 38000, Pakistan to examine the TU-mediated fluctuations in some crucial physio-biochemical parameters and the oxidative defense of potatoes under a restricted water supply. For this purpose, two potato cultivars (potato-SH-5 and potato-FD-73) were sown in pots containing 10 kg of soil. Water was regularly applied to the pots until germination. After 2 weeks of germination, drought stress with 65% field capacity was imposed, while the control was subjected to 100% field capacity. TU, as a rooting medium, was applied at the vegetative stage (0 (no application), 0.5, 0.75 mM). A substantial reduction in the total number of leaves, leaf area, tuber biomass (fresh and dry weight), photosynthetic pigments, membrane permeability, and leaf relative water content (RWC) was recorded in plants under drought stress conditions as compared to control plants. The damaging effects of water stress were more critical for cv. potato-FD-73 as compared to cv. potato-SH-5. In contrast, drought stress enhanced the malondialdehyde (MDA) and hydrogen peroxide (H2O2) content while also increased antioxidant enzyme activities (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and triggered the accumulation of soluble proteins, soluble sugars, proline, and phenolic and anthocyanin contents. However, TU applied as rooting medium at 0.5 and 0.75 mM was effective in reducing the detrimental effects of water stress in both cultivars. Furthermore, increasing levels of TU enhanced chlorophyll pigments, dissolved proteins, complete dissolved sugars, and enzymatic capabilities of POD, SOD, and CAT, while reducing the MDA and H2O2 in both cultivars under stress conditions. In conclusion, TU improved the yield and chlorophyll pigments of potato plants by mitigating the adverse effects of drought stress through reduced EL, MDA, and H2O2 contents and improved activities of enzymatic and non-enzymatic antioxidants and osmoprotectants.

Application of sewage sludge combined with thiourea improves the growth and yield attributes of wheat (Triticum aestivum L.) genotypes under arsenic-contaminated soil.

Arsenic (As) contamination is a serious threat to agriculture and human health worldwide. It can adversely affect the growth attributes of food crops. On the other hand, using thiourea (TU) to ameliorate As stress is an economically consistent approach. However, there is a knowledge gap regarding the combined use of TU and Sewage sludge (SS). SS is considered important, unutilized biomass. It can be used as a fertilizer that has high organic matter and nutrients. Therefore, the current study was performed to evaluate TU and SS sole and combined responses under As toxicity on two wheat genotypes (Markaz 19 and Ujala 16). There were four treatments control (As 50 mg kg-1), SS (30 g kg−1)+TU (6.5 mM)+As, TU+As and SS+As applied with four replications. Results revealed that SS+TU performed significantly better over SS, TU and control for improvement in root and shoot fresh and dry weight of wheat varieties Markaz 19 and Ujala 16 under As toxicity. A significant decrease in POD, SOD and APX of Markaz 19 and Ujala 16 also validated the effective functioning of SS+TU over control. The maximum increase of 71 and 77% was noted in phosphorus, where SS+TU was applied over control in Markaz 19 and Ujala 16, respectively. In conclusion, SS+TU is a better approach than the sole application of SS and TU under As contamination for improvement in wheat growth attributes. More investigations are recommended at the field level under different As contamination and agro-climatic zones to declare SS+TU an effective amendment to mitigate As toxicity in wheat.

Oxalic acid modified hexagonal ZnIn2S4 combined with bismuth oxychloride to fabricate a hierarchical dual Z-scheme heterojunction: Accelerating charge transfer to improve photocatalytic activity

Multivariate organic acids can modify the structure and morphology of materials to some extent. In this work, the addition of oxalic acid can make the morphology of ZnIn2S4 become uniform, the crystal structure of ZnIn2S4 can change from cubic to hexagonal, and the photocatalytic activity was improved. The dual Z-scheme ZnIn2S4/BiOCl heterojunction was successfully fabricated by a two-step hydrothermal-hydrolytic method. The concept of green chemistry was used to make full use of thiourea, and the rapid decomposition of Rh B and TC was realized by ZIS/BOC-8 under visible light in a shorter period time than other photocatalysts in this system. In order to investigate the relationship between the structure and properties of the catalyst, XRD, FT-IR, SEM, HRTEM, UV–vis DRS, XPS and other characterization technologies were used to analyze the structure, morphology, optical properties of the samples, showing that ZnIn2S4/BiOCl have been successfully synthesized indicates the existence of Z-scheme heterojunction structure. PL, TRPL and EIS analysis showed that the Z-scheme heterostructures could rapidly promote the separation of holes and photo-induced electron carriers, enhancing the photocatalytic performance and stability. The photocatalytic degradation results showed that the degradation rate of Rh B and TC by ZIS/BOC-8 were more than 92% within 30 min, comparing with other catalyst, ZIS/BOC-8 showed preferable visible light catalytic degradation activity, and the order of catalytic activity was as follows: ZIS/BOC-8 > BiOCl-S > BiOCl, ZnIn2S4. Moreover, the degradation pathway of Rh B was discussed by 3D-EEM and LC-MS, and the photocatalytic mechanism of the system was proposed, especially the mechanism of photocatalytic degradation of Rh B by ZIS/BOC under visible light.

Cuprous or cupric? How substrate polarity can select for different phases of copper sulfide films in chemical bath deposition.

Copper sulfides have many applications from thermoelectrics to biotechnology. While the properties of different copper sulfide phases are well understood, controlling the deposited copper sulfide stoichiometry remains a significant challenge, especially in solution-phase synthesis techniques. In this work, we investigate the chemical bath deposition of CuxS on functionalized self-assembled monolayers (SAMs). Time-of-flight mass spectrometry, Raman spectroscopy, and x-ray photoelectron spectroscopy are employed to analyze the deposited films. We show that the use of thiourea as a sulfur source leads to the deposition of different copper sulfide phases and is controlled by the interaction of sulfur-containing ions in solution with the functionalized SAMs. For -COOH terminated SAMs, copper sulfide deposition is controlled by the surface polarity of the substrate. At the bath pH used in these experiments, the -COOH terminal groups are deprotonated. The resulting -COO- terminated SAM surface repels negatively charged sulfur-containing ions, leading to the deposition of Cu2S. For -CH3 terminated SAMs, which are non-polar, there is no specific interaction between the SAM terminal group and sulfur-containing ions and CuS is deposited. For -OH terminated SAMs, which have a polar terminal group, there are two competing effects: the repulsion of S-containing ions by the small negative charge of the terminal -OH group and the increase in the concentration of sulfur-containing ions in solution as the bath pH increases. This competition leads to the deposit stoichiometry changing from Cu2S at pH 9 to CuS at pH 12.

Response of paddy (Oryza sativa) to exogenous application of bio-regulators in soils irrigated with alkali groundwater

Exogenous applications of plant bio-regulators (PBRs) were evaluated during kharif of 2017 and 2018 for their efficiency to facilitate growth and production processes in paddy (Oryza sativa L.) grown in loam soils undergoing sodification (pHs 8.5 & 8.3; ESP 37 & 13) with alkali groundwater irrigation (RSC 3.4 meq L-1 at site-I during both the years and RSC 4.4 & 3.7 meq l-1 at site-II during 2017 and 2018, respectively). The PBRs included gibberellic acid (GA, 25 ppm), potassium nitrate (PN, 15 g l-1), salicylic acid (SA, 10uM), sodium benzoate (SB, 150 mg l-1; 2017 only) and thio-urea (TU, 500 ppm). These were sprayed at three stages, i.e. seedling establishment and tillering (30-40 days after transplanting), booting and maximum growth (50-60 DAT) and flowering and grain formation (80-90 DAT). PBRs promoted growth and improved yields and contributing attributes like tillers, panicle length and filled grains. The increase in grain yield equaled 20, 16, 2, 16 and 24% with application of GA, PN, SA, SB and TU, respectively at Site-I during 2017 and the counter values at Site-II were 4, 24, 2, 17 and 21%. Similarly, during 2018, the improvements in yield equaled 3, 15, 4 and 20% with GA, PN, SA and TU at Site-I and nil, 14, 8 and 7% at Site- II, respectively. The Na:K ratio was lower especially with PN while grain quality monitored in terms of protein and gluten contents remained unaffected. On the basis of consistency, it emerges that the use of thio-urea and potassium nitrate is a viable option for alleviating sodicity stress in paddy under alkali groundwater irrigated conditions.

Synthesis, Molecular Docking, and Preliminary Evaluation of 2-(1,2,3-Triazoyl)benzaldehydes As Multifunctional Agents for the Treatment of Alzheimer's Disease.

We described here our results on the use of thiourea as a ligand in the copper catalysed azide-alkyne cycloaddition (CuAAC) of 2-azidobenzaldehyde with alkynes. Reactions were performed reacting 2-azidobenzaldehyde with a range of terminal alkynes using 10 mol % of copper iodide as a catalyst, 20 mol % of thiourea as a ligand, triethylamine as base, DMSO as solvent at 100 °C under nitrogen atmosphere. The corresponding 2-(1H-1,2,3-triazoyl)-benzaldehydes (2-TBH) were obtained in moderated to excellent yields and according our experiments, the use of thiourea decreases the formation of side products. The obtained compounds were screened for their binding affinity with multiple therapeutic targets of AD by molecular docking: β-secretase (BACE), glycogen synthase kinase (GSK-3β) and acetylcholinesterase (AChE). The three compounds with highest affinity, 5 a (2-(4-phenyl-1H-1,2,3-triazol-1-yl)benzaldehyde), 5 b (2-(4-(p-tolyl)-1H-1,2,3-triazol-1-yl)benzaldehyde), and 5 d (2-(4-(4-(tert-butyl)phenyl)-1H-1,2,3-triazol-1-yl)benzaldehyde) were selected and evaluated on its antioxidant effect, in view of select the most promising one to perform the in vivo validation. Due the antioxidant potential ally to the affinity with BACE, GSK-3β and AChE, compound 5 b was evaluated in a mouse model of AD induced by intracerebroventricular injection of streptozotocin (STZ). Our results indicate that 5 b (1 mg/kg) treatment during 20 days is able to reverse the cognitive and memory impairment induced by STZ trough the modulation of AChE activity, amyloid cascade and GSK-3β expression.

New catalytic effect of thiourea on the oxidative cyanation of N-aryltetrahydroisoquinolines

Thiourea itself has been introduced as a mild and efficient organocatalyst for the oxidative α -cyanation of N-aryltetrahydroisoquinolines (THIQs) with trimethylsilyl cyanide (TMSCN), giving the corresponding products in good to excellent yields. Experimental investigations demonstrated that thiourea acts as a radical initiator by abstracting hydroxyl radical (OH) from tert-butyl hydroperoxide (TBHP) directly instead of non-covalent hydrogen bondings (H-bondings) activation. The use of thiourea as a radical initiator offers a new avenue for innovative chemical transformations in organocatalyzed radical chemistry.

Effect of an organic additive in the electrolyte on suppressing the growth of Li dendrites in Li metal-based batteries

Lithium metal has attracted much attention as an anode material for high-performance batteries owing to its high specific capacity and electrode potential. However, the Li metal electrode could suffer from the dendritic growth of Li during the cell operation due to the high reactivity of Li with organic electrolytes. To address this issue, we propose the use of thiourea as an electrolyte additive for Li metal-based batteries. The thiourea additive in LiTFSI/TEGDME electrolyte allowed the formation of a stable and uniform solid electrolyte interface layer on the Li electrode, thereby aiding the suppression of dendritic growth of Li and further electrolyte decomposition. Accordingly, a Li symmetric cell containing the thiourea additive exhibited six-times longer cycle life than a cell without the additive. Further, the electrolyte additive was also successfully employed in a Li-O2 cell to improve its cyclability.

Chiral ligand-exchange separation and determination of malic acid enantiomers in apple juice by open-tubular capillary electrochromatography

This study describes the application of an open tubular capillary column for chiral ligand-exchange separation and determination of malic acid enantiomers in apple juice by open-tubular capillary electrochromatography (OT-CEC). The open tubular column was prepared by in-situ grafting polymerization of 3-chloro-2-hydroxypropyl methacrylate (HPMA-Cl) and followed by l-Histidine (l-His) modification. l-His was used as a chiral ligand-exchange selector and copper (II) as a central ion. The electrochromatographic characterization of the open tubular column was performed with the use of thiourea as an electroosmotic flow (EOF) marker. Factors affecting electrochromatographic enantioseparation of malic acid were also studied. The running buffer conditions for optimum enantioseparation of malic acid were found to be ACN/5.0mM CuSO4, 20.0mM (NH4)2SO4 (60/40%, v/v) adjusted to pH 3.0. The separation and determination of the enantiomers of malic acid in the apple juice solution diluted 10- to 40-folds were successfully achieved.

Effect of application of SH-compounds on yield, protein and economics of summer green gram [Vigna radiata(L.) WILCZEK] under moisture stress in north Gujarat conditions

A quadreplicated split plot design field experiment with two main plot treatments and weight subplot treatments were conducted during summer 2011. Both the SH compounds and water was sprayed twice i.e., 25 and 45 DAS. Seed yield was not influenced but stover yield was significantly reduced due to moisture stress at vegetative stage (M2). Moisture stress did not influence protein content and protein yield. Crop without moisture stress (M1) produced higher net return and cost benefit ratio (CBR). Use of Thiourea 500 ppm (S4) increased seed and stover yield by 58 and 84% respectively over control (S1). Protein content and yield also increased with thiourea application @ 500 ppm (S4) over the SH compounds. Net return and CBR was highest with Thiourea 500 ppm. Use of thiourea @ 500 ppm without moisture stress earned maximum while moisture stress with control recorded the lowest net return and CBR. Foliar spray of thiourea@ 500 ppm twice at 25 and 45 DAS proved most effective to get higher yield and net return from summer greengram.

ChemInform Abstract: Thioureas as Ligands in Organometallic Reactions

AbstractReview: [56 refs.

Thiourea-based fluorescent chemosensors for aqueous metal ion detection and cellular imaging.

We describe three significant advances in the use of thioureas as reporting elements for metal-responsive fluorescent chemosensors. First, on the basis of the crystal structure of a chemosensor analogue, we provide a deeper understanding of the details of the thiourea coordination environment. Second, we describe a new generation of chemosensors with higher affinities for Zn(2+) and Cd(2+) than were observed for earlier probes, expanding the scope of this type of probe beyond Hg(2+) detection. Third, we show that a thiourea-based chemosensor can be employed for fluorescence microscopy imaging of Hg(2+) ion concentrations in living mammalian cells.

Thioureas as Ligands in Organometallic Reactions

Thioureas are air and moisture stable, and they can coordinate to various metal centers, making their derivatives versatile ligands for transition-metal-catalyzed reactions. This account provides an overview of recent developments in the use of thioureas as ligands in organometallic-catalyzed reactions, with particular emphasis on their application to the total synthesis of natural products. 1 Introduction 2 Development of Thioureas as Ligands in Transition-Metal-Catalyzed Reactions 2.1 Carbonylative Annulation 2.2 Pauson–Khand Reaction (Intramolecular and Intermolecular) 2.3 Thiourea–Palladium-Catalyzed Carbonylation of Terminal Olefins 2.4 Thiourea–Palladium-Catalyzed Heck Coupling Reaction 2.5 Suzuki Coupling and Suzuki Carbonylative Reaction 2.6 Negishi Coupling 2.7 Other Reactions 3 Applications in Total Synthesis of Natural Products 3.1 (±)-Schindilactone A 3.2 Crisamicin A 4 Conclusion and Outlook