Amine Type Research Articles

In-situ rapid construction of aliphatic amine combined polyamide seawater reverse osmosis membrane for efficient boron removal

Polyamide (PA) reverse osmosis membranes are commonly employed in seawater desalination owing to their effective salt rejection and water permeability; however, the elimination of small and neutral boron molecules from seawater remains a significant hurdle in energy-efficient and cost-effective desalination processes. In this work, a seawater reverse osmosis (SWRO) membrane with powerful boron removal competence was designed by adopting an in-situ rapid integration protocol, which utilized aliphatic amines as hydrophobic barriers by bonding the residual chloride groups upon the membrane surface and as molecular plugs by embedding in the PA networks. Consequently, it resulted in a notable improvement in the rejection of neutral boron molecules due to enhanced steric hindrance caused by immobilized amine plugs and synergistically tunned hydrophobic interactions. The permeability coefficient of boron decreased from 4.8 to 0.9 L m−2 h−1, and the boron rejection increased from 80.7 to 90.5% under the modification conditions with the optimal type and concentration of amines, while displaying a NaCl rejection of 99.8% and an acceptable water permeability of 0.55 L m−2 h−1 bar−1. Meanwhile, the alteration of membrane chemical compositions and structure properties was kept to a minimum. This study offers intuitive insights into the critical roles played by the aliphatic amines in the selective layer of the membrane for the removal of neutral boron molecules and salts, thereby enabling the fabrication of highly selective SWRO membranes, which may have significant implications for more efficient membrane-based seawater desalination and boron removal.

Direct air capture on amine-impregnated FAU zeolites: Exploring for high adsorption capacity and low-temperature regeneration

To develop an efficient adsorbent for direct air capture (DAC), capturing 400 ppm of CO2 in simulated air was investigated for amine-impregnated faujasite (FAU) zeolite. Six types of amines were used: monoethanolamine (MEA), diethylenetriamine (DETA), ethylenediamine (EDA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and polyethylenimine (PEI; average molecular weight = 600). To evaluate the Si/Al ratio, FAU zeolites with different Si/Al ratios (2.75–300) were prepared by dealumination and used for impregnation. The 400 ppm CO2 adsorption under dry conditions was performed using a thermogravimetric (TG) analyzer, while humid condition test was conducted using a breakthrough measurement instrument. Under dry conditions, 40 wt% of PEI-impregnated FAU zeolite showed high CO2 adsorption capacity of 0.64 mmol g−1 and an adsorption rate of 0.035 mmol g−1 min.−1. Additionally, the capacity of DETA-impregnated samples showed a relatively high capacity of 0.40 mmol g−1. With an increase in the Si/Al ratio of FAU zeolite, the adsorption capacity of the DETA-impregnated samples increased, whereas the PEI-impregnated samples retained an adsorption capacity of approximately 0.64 mmol g−1. Under humid conditions, an enhanced adsorption capacity (1.54 mmol g−1) was observed for the PEI-impregnated FAU samples. It is noteworthy that purging at 25 °C without additional heat treatment resulted in the release of CO2 from the DETA-impregnated samples after adsorption. The amount of released CO2 after purging the DETA-impregnated samples was up to 0.27 mmol g−1. PEI- and DETA-impregnated FAU zeolites showed excellent regeneration stability over 10 adsorption cycles under humid conditions.

Capture of CO2 Using Mixed Amines and Solvent Regeneration in a Lab-Scale Continuous Bubble-Column Scrubber

This study used monoethanolamine (MEA) as an amine-based solvent, which was blended with secondary amines (DIPA), tertiary amines, stereo amines, and piperazine (PZ) to prepare mixed amines at the required concentrations, which were used as the test solvents. To search for the best-mixed amines, a continuous bubble-column scrubber was adopted to explore the performance of mixed solvents presented in this study. The solvent regeneration test was also carried out at different temperatures. The selected factors included the type of mixed amine (A), the ratio of mixed amines (B), the liquid feed flow (C), the gas flow rate (D), the concentration of mixed amines (E), and the liquid temperature (F), each having five levels. Using the Taguchi experimental design, the conventional experimental number could be reduced from 15,625 to 25, saving much time and cost. The absorption efficiency (EF), absorption rate (RA), overall mass-transfer coefficient (KGa), and absorption factor (ϕ) were estimated as the indicators. After the Taguchi analysis, E, D, and C were found to play important roles in the capture of CO2 gas. Verifications of optimum conditions were found to be 100%, 19.96 × 10−4 mole/s·L, 1.2312 1/s, and 0.6891 mol-CO2/L·mol-solvent for EF, RA, KGa, and ϕ, respectively. The evaluated indexes suggested that MEA + PZ was the best-mixed amine, followed by MEA and MEA + DIPA. The solvent regeneration tests for the scrubbed solutions performed at different optimum conditions showed that the heat of the regeneration sequence was in the order of MEA > MEA + PZ > MEA + DIPA with minimum energy required at 110 °C. The individual energy required was also analyzed here.

Comparison of characteristics and performance between PEI and DETA impregnated on SBA-15 for CO2 capture

Solid amine adsorbents have attracted much attention as a promising alternative to amine scrubbing. However, there have been few studies systematically comparing the differences between adsorbents modified with macromolecular amines and small molecular amines. This study selected polyethyleneimine (PEI) and diethylenetriamine (DETA) to impregnate into SBA-15 and set amine types (PEI and DETA), amine loadings (0%-50%), and temperatures (20–120 °C) as parameters, trying to provide advice for amine selection and practical application. The adsorbents modified with DETA had higher amine dispersion, while the adsorbents modified with PEI performed better at thermal stability, adsorption capacity, and adsorption kinetics. SBA-15 modified with 50% PEI could reach a CO2 uptake of 182.11 mg/g and an amine efficiency of 0.353. It also presented superior adsorption kinetics with a peak adsorption rate of 350 mg/(g · min) and could reach 90% CO2 adsorption capacity in 5 min, which controlled the activation energy below 7 kJ/mol. What’s more, the modified adsorbent had excellent cyclic stability, showing only 6.14% decay after 30 cycles. The double-exponential model was also investigated to explain the inherent properties. The 50%-PEI-modified SBA-15 proved to be a promising and efficient solid adsorbent for CO2 capture.

Cascade Transformation of the Ansamycin Benzoquinone Core into Benzoxazole Influencing Anticancer Activity and Selectivity.

The metal-free cascade transformation of geldanamycin benzoquinone core is proposed at relatively mild conditions. This approach yields new benzoxazole ansamycin antibiotics and enables their functionalization in an atom-economic manner, irrespective of the type of amine used. The analysis of the heterocyclization course reveals the dependence of its rate on the nature of the para-substituent within the benzylamine moiety (EDG/EWG) and the strength of the base. The reduction of the ansamycin core enables an increase in anticancer potency and selectivity.

Preparation of nitrogen-containing compounds and nitrogen-doped biochar via nitrogen-rich pyrolysis coupled with ammonia source impregnation

Using lignocellulose to produce nitrogen-rich bio-oil and nitrogen-doped biochar in the presence of nitrogen-carrying bodies has become a research hotspot in recent years for high-value conversion and utilization of biomass. Different nitrogen carriers significantly influence biomass pyrolysis and conversion process and products. In this study, a new strategy for the preparation of both nitrogen-rich bio-oil (high-value N-containing compounds (NCCs)) and N-doped biochar by ammonia impregnation treatment coupled with Zeolite Socony Mobil Five (HZSM-5) via N-enriched pyrolysis was proposed. The influence of amine type (formamide, urea, melamine and dicyandiamide) and concentration on the product content, distribution, properties and evolution mechanism was also explored. The results showed that the amine treatment significantly reduced the activation energy (from 23.71 kJ/mol to 12.35–20.82 kJ/mol) and N content (from 7.42% to 6.05–7.29%) due to destruction of the crystalline phase and amine volatilization but increased the amount of char formed (from 18.15% to 21.47–24.06%). The amino groups derived from four different ammonia sources (formamide, urea, melamine and dicyandiamide) reacted with biomass-derived O-containing compounds to form pyridinic- and graphitic-like biochar due to NH3 etching and activation, and the enhanced adsorption capacities decreased in the order melamine (107.95 m2/g) > urea (96.84 m2/g) > dicyandiamide (79.46 m2/g) > formamide (74.12 m2/g) > biochar (35.63 m2/g)) due to the higher specific surface areas, pore volumes, graphitization degrees and enrichment of the O/N-containing functional groups. Additionally, higher concentrations of formamide coupled with the HZSM-5 catalyst noticeably boosted the NCCs content and pyrrole selectivity. The maximum NCCs content and pyrrole selectivity were 82.97% and 52.45%, respectively, and these were obtained via catalytic pyrolysis with HZSM-5 when the formamide concentration was 15%. Furthermore, formamide preferentially generated NCCSs and pyrroles via the Maillard reaction, and urea facilitated amine formation. This research provides useful background knowledge and a novel process for transformation and recovering high value-added NCCs products by N-rich pyrolysis of ammonia impregnated biomass.

Technical performance and environmental assessment of an ionic liquid-based CCS process for hydrogen production

Hydrogen (H2) production combined with carbon capture and storage (CCS) is anticipated to be an important technology contributing to reduce the carbon footprint of current fossil-based H2 production systems. This work addresses for the first time the techno-environmental assessment of a CCS process based on the ionic liquid [Bmim][Acetate] for H2 production by steam methane reforming (SMR) and the comparison to conventional amine-based systems. Two different SMR plants using MDEA or [Bmim][Acetate] for CO2 capture were rigorously modelled using Aspen Plus to compute material and energy needs and emissions. Literature and simulation results were then used to perform a life cycle impact assessment (LCIA) of these processes based on the ReCiPe model. Solvent synthesis, CCS process and hydrogen production stages were considered for the cradle-to-gate analysis. Results showed that although [Bmim][Acetate] is a priori more harmful to the environment than amines (in a kg-to-kg comparison), LCIAs carried out for both CCS processes showed from 5 to 17 % lower environmental impacts values for all estimated categories when using [Bmim][Acetate] due to a 9.4 % more energy-efficient performance than MDEA, which also reduced a 17.4 % the total utility cost. Indeed, if a typical amine loss rate of 1.6 kg/tCO2 is assumed, the values of the environmental impacts increase up to 14 % for the IL-based CCS plant, but still maintaining its favorable results over MDEA. As consequence, the SMR plant with the IL-based CCS system exhibited 3–20 % lower values for most of the studied impact categories. These results contribute to shed some light on evaluating the sustainability of ILs with respect to conventional solvents for CO2 capture and to guide the synthesis of new more sustainable ILs but also, they would be used to compare the environmental burdens from the synthesis and process performance of other promising ILs for CO2 capture that are not environmentally assed yet.

Mannich Reaction: Review of Amine‐Functionalized Lignin Derivatives and Their Applications

AbstractIn recent years naturally resourced materials have played a significant role in many applications ranging from biomedical to automotive applications. Among them, lignin has received much attention towards these applications owing to its abundance and readily modified chemical structures. Recent research studies have focused on various chemical modifications of lignin, including the increasingly popular Mannich reaction that aminates the lignin structure to expand the applicability of lignin in advanced fields. This article reviews the recent Mannich reaction‐based lignin developments with different types of amines used in lignin modifications and discusses how the reaction enhances functionality in engineering, biomedical and environmental technology applications.

A Bioactive Synthetic Outer-Core Oligosaccharide Derived from a Klebsiella pneumonia Lipopolysaccharide for Bacteria Recognition.

There is an urgent need for new treatment options for carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae), which is a common cause of life-threatening hospital- and community-acquired infections. Prophylactic or therapeutic vaccination may offer an approach to control these infections, however, none has yet been approved for human use. Here, we report the chemical synthesis of an outer core tetra- and pentasaccharide derived from the lipopolysaccharide of K. pneumoniae. The oligosaccharides were equipped with an aminopentyl linker, which facilitated conjugation to the carrier proteins CRM197 and BSA. Mice immunized with the glycoconjugate vaccine candidates elicited antibodies that recognized isolated LPS as well as various strains of K. pneumoniae. The successful preparation of the oligosaccharides relied on the selection of monosaccharide building blocks equipped with orthogonal hydroxyl and amino protecting groups. It allowed the differentiation of three types of amines of the target compounds and the installation of a crowded 4,5-branched Kdo moiety.

In-situ preparation of Cu-BTC modified with organic amines for H2S removal under ambient conditions

Amine modification is an effective strategy to improve the H2S removal performance of Cu-BTC. In order to avoid the problem of pore blockage after amine modification in post synthesis impregnation, herein a series of Cu-BTC modified with organic amine adsorbents were prepared via an in-situ one-pot method and the H2S removal performance under ambient conditions was tested. It is found that the introduced organic amines, depending on the types of amine selected, have a significant influence on the growth of Cu-BTC and its textural properties. The H2S removal performance on the as-prepared materials suggested that the amine modified samples remarkably improved the H2S removal capacities with an order of BA-Cu-BTC > TEA-Cu-BTC > TEOA-Cu-BTC > Cu-BTC. Besides the enlarged surface area and the increased mesopores volumes, BA has the advantages of smaller steric hindrance and –NH2 groups, among which the former increased the accessibility of Cu active sites while the latter acted as additional active sites for H2S capturing, thus affording BA-Cu-BTC highest breakthrough capacity of 77.3 mg S/g. Overall, this study elaborates the effect of organic amines in-situ modification on the Cu-BTC structure and desulfurization.

The Structural Characteristics of Compounds Interacting with the Amantadine-Sensitive Drug Transport System at the Inner Blood–Retinal Barrier

Blood-to-retina transport across the inner blood-retinal barrier (BRB) is a key determinant of retinal drug concentration and pharmacological effect. Recently, we reported on the amantadine-sensitive drug transport system, which is different from well-characterized transporters, at the inner BRB. Since amantadine and its derivatives exhibit neuroprotective effects, it is expected that a detailed understanding of this transport system would lead to the efficient retinal delivery of these potential neuroprotective agents for the treatment of retinal diseases. The objective of this study was to characterize the structural features of compounds for the amantadine-sensitive transport system. Inhibition analysis conducted on a rat inner BRB model cell line indicated that the transport system strongly interacts with lipophilic amines, especially primary amines. In addition, lipophilic primary amines that have polar groups, such as hydroxy and carboxy groups, did not inhibit the amantadine transport system. Furthermore, certain types of primary amines with an adamantane skeleton or linear alkyl chain exhibited a competitive inhibition of amantadine uptake, suggesting that these compounds are potential substrates for the amantadine-sensitive drug transport system at the inner BRB. These results are helpful for producing the appropriate drug design to improve the blood-to-retina delivery of neuroprotective drugs.

Synthesis and characterization of N-acyl alkanolamide surfactant from fatty acids and alcohol amines using sodium methoxide catalyst

Surfactant is a substance added to the liquid that improves the spread's properties by weakening the liquid's surface voltage. Surfactants have a molecular structure consisting of hydrophilic groups and hydrophobic groups. Surfactant needs in Indonesia continue to increase along with the development of industries in Indonesia. This study will be synthesized by the N-acyl surfactant alkanolamide using one type of alcohol amine, namely diethanolamine, through a reaction of amidation between fatty acids and using organic solvents tert-amyl alcohol. The catalyst used is a chemical catalyst, namely sodium methoxide. Furthermore, the purpose of this research is to determine the effect of reaction variables and determine the characteristics of the N-acyl alkanolamide surfactant in the form of acidic numbers and spreading numbers. This study showed for lauric acid, palmitate acid, and the best stearate acid at 90 oC reaction temperatures and 2-hour reaction times, while the best succinic acid at 100 oC and a reaction time of 2 hours. The relationship between reaction rate and time is directly proportional; the longer the reaction time, the higher the rate. The conversion relationship with reaction time is directly proportional, where conversion will increase with the increase in reaction time. However, this does not happen to all fatty acids. Due to the increase in reaction time, it will not provide significant results on surfactant products. The relation between the reaction temperature and the conversion acquisition at the time obtained decreased along with the increase in reaction temperatures. The acid numbers in the best conditions in a row are 40.67 for N-palmitoyl diethanolamine, 47.41 for N-lauroyl diethanolamine, 63.11 for N-succinyl diethanolamine, and 22.44 for N-stearoyl diethanolamine. The saponification number in the best conditions in a row is 36.47 for N-palmitoyl diethanolamine, 23.84 for N-lauroyl diethanolamine, 57.50 for N-succinoyl diethanolamine, and 7.01 for N-stearoyl diethanolamine.

Contributions of CH4-amine interactions by primary, secondary, and tertiary amines on CO2/CH4 separation efficiency

In designing amine-incorporated adsorbents for CO2/CH4 separation, it is essential to understand the individual effects amine moieties have on the separation of CO2/CH4 mixtures. In this work, primary, secondary, and tertiary amines are moderately grafted on SBA-15 to examine factors affecting adsorption of CO2 and CH4. Materials were characterised by thermogravimetric and elemental analysis, and their performance was measured by volumetric and gravimetric gas adsorption. An amine density of 1.6–1.7 mmol/g in secondary and tertiary amines showed an equivalent CH4 uptake of <0.04 mmol/g at 25 °C, while primary amines adsorbed 0.05 mmol/g, indicating stronger interaction forces with CH4. In terms of selectivity, primary and secondary amines grafted at 1.3–1.4 mmol/g had similar values, unaffected by amine type. Adsorption results cross analysed with DFT simulations indicate similar binding energies for CH4 by both amine moieties, concluding the facilitated access of gas molecules to primary amine moieties is the primary factor dictating degree of adsorption. At an amine density of ∼ 1.7 mmol/g for both primary and secondary amines, an increase in temperature from 25 to 40 °C at a CO2 partial pressure of 40 kPa showed a decrease in CO2/CH4 selectivity of only primary amines. Secondary amines are thus more selective amine moieties at these conditions. Furthermore, in isothermal adsorption–desorption conditions, moderately grafted secondary amines have an equal working capacity to primary amines. Both these qualities support secondary amines at moderate densities as candidates for adsorbent development in CO2/CH4 separations.

Determination of Anthraquinone-Tagged Amines Using High-Performance Liquid Chromatography with Online UV Irradiation and Luminol Chemiluminescence Detection

Quinones are frequently used as derivatization reagents in HPLC analysis to improve detection sensitivity. In the present study, a simple, sensitive, and selective chemiluminescence (CL) derivatization strategy for biogenic amines, prior to their HPLC-CL analysis, was developed. The novel CL derivatization strategy was established based on using anthraquinone-2-carbonyl chloride as derivatizing agent for amines and then using the unique property of the quinones' moiety to generate reactive oxygen species (ROS) in response to UV irradiation. Typical amines such as tryptamine and phenethylamine were derivatized with anthraquinone-2-carbonyl chloride and then injected into an HPLC system equipped with an online photoreactor. The anthraquinone-tagged amines are separated and then UV-irradiated when they pass through a photoreactor to generate ROS from the quinone moiety of the derivative. Tryptamine and phenethylamine can be determined by measuring the chemiluminescence intensity produced by the reaction of the generated ROS with luminol. The chemiluminescence disappears when the photoreactor is turned off, suggesting that ROS are no longer generated from the quinone moiety in the absence of UV irradiation. This result indicates that the generation of ROS could be controlled by turning the photoreactor on and off. Under the optimized conditions, the limits of detection for tryptamine and phenethylamine were 124 and 84 nM, respectively. The developed method is successfully applied to determine the concentrations of tryptamine and phenethylamine in wine samples.

An approach for the synthesis of carboxylic acid via phenacyl bromides and diethylamine by oxidative C–C bond cleavage

An approach for the synthesis of carboxylic acid was achieved via oxidative C–C bond cleavage. Oxygen in the air participates in the reaction as an oxidant. It's found that many types of amines can promote this type reaction.

Readily regenerable amine-free CO2 sorbent based on a solid-supported carboxylate ionic liquid

Accumulation of anthropogenic CO2 is undoubtedly the major cause of global warming. In addition to reducing emissions, minimising the threatening effects of climate change in the near future might also require the capture of enormous amounts of CO2 from point sources or from the atmosphere. In this regard, the development of novel affordable and energetically attainable capture technologies is greatly needed. In this work, we report rapid and greatly facilitated CO2 desorption for amine-free carboxylate ionic liquid hydrates as compared to a benchmark amine-based sorbent. Complete regeneration was achieved at moderate temperature (60 °C) over short capture-release cycles using model flue gas on a silica-supported tetrabutylphosphonium acetate ionic liquid hydrate (IL/SiO2), whereas the polyethyleneimine counterpart (PEI/SiO2) only recovered half its capacity after the first cycle in a rather sluggish release process under the same conditions. The IL/SiO2 sorbent achieved a slightly superior working CO2 capacity than PEI/SiO2. The easier regeneration of carboxylate ionic liquid hydrates, which behave as chemical CO2 sorbents leading to bicarbonate in a 1:1 stoichiometry, is due to their relatively low sorption enthalpies (≈40 kJ mol−1). The faster and more efficient desorption from IL/SiO2 fits a first-order kinetic model (k = 0.73 min−1), whereas a more complex process was observed for PEI/SiO2 (pseudo-first order initially, k = 0.11 min−1, pseudo-zero order at later stages). The remarkably low regeneration temperature, the absence of amines and the non-volatility of the IL sorbent are favourable assets to minimise gaseous stream contamination. Importantly, regeneration heats —a crucial parameter for practical application— are advantageous for IL/SiO2 (4.3 kJ g (CO2)−1) vs. PEI/SiO2, and fall within the range of typical amine sorbents indicating a remarkable performance at this proof-of-concept stage. Further structural design will enhance the viability of amine-free ionic liquid hydrates for carbon capture technologies.

Zinc Promoted Urea Synthesis Using Carbonyldiimidazole as Carbonyl Source and Its Application for the Synthesis of Cariprazine

AbstractA convenient method has been developed for symmetrical and un‐symmetrical urea synthesis by using Carbonyldiimidazole (CDI) and recyclable activated zinc metal. This reaction is suitable for all types of amines and gives the desired urea products with good to excellent yield. The developed synthetic approach was employed for the synthesis of the Cariprazine drug.

Investigation of CO2 adsorption performance of amine impregnated adsorbents using amine-support matching strategies

Supports and the organic amine type are the main factors affecting the performance of adsorbents. Currently, researchers are focusing on the development of supports, but their high cost limits the applications. In addition, there is a lack of studies on the mechanism of matching organic amines to supports. This paper presents a feasible strategy including the preparation of low-cost mesoporous nano-SiO2 (B-SiO2) support from blast furnace slag (BFS). A series of adsorbents were obtained by impregnating with different organic amines on the B-SiO2 support to identify the most suitable amine type for B-SiO2. The results showed that the matching degree four amines with B-SiO2 was TETA > TEPA > PEHA > PEI in order. TETA at 35 wt.% was the best matched amine for B-SiO2, exhibiting the highest CO2 adsorption capacity of 112.89 mg/g and the best adsorption energy Eads = −87.21 kJ/mol at 80 ℃. This is mainly due to two reasons. On the one hand, TETA is easily dispersed in the pores of the support, which not only effectively prevents the agglomeration effect and improves the accessibility of the active site, but also facilitates the inhibition of amine leaching. On the other hand, TETA has the least steric hindrance and the highest affinity for CO2, thus reducing the mass transfer resistance and improving the adsorption performance. In addition, four adsorption kinetic models were developed. The Avrami model was the best fit for four adsorbents. It indicates that the adsorption mechanism of this type of adsorbent is a combination of physical and chemical adsorption. This study reveals the matching rules between amine species and supports, and provides theoretical guidance for the preparation of solid amine-based adsorbents.

Acylated anthocyanin inhibited the formation of heterocyclic amines in hybrid chemical model system and its underlying mechanism

Enzymatic acylation was employed to synthesize acylated anthocyanin, and a hybrid chemical model system was used for the formation of heterocyclic amines. And the inhibition effect and underline mechanism were investigated by analyzing the variations in important precursors and intermediates. Results confirmed that cyanidin-3-(6-cinnamoyl) -glycosidase (C3(6C)G) with a purity of 98.9% was obtained. HPLC identified seven types of heterocyclic amines (IQ, MeIQx, 4,8-DimeiqX, Norharman, Harman, PhIP, and AαC) generated in the chemical model. (C3(6C)G) showed a good concentration-dependent manner for the inhibition effect on most HCAs except for MeIQx and PhIP. It also suppressed the glucose content, showed a dose-dependent manner in creatine/creatinine inhibition, and could scavenge formaldehyde, acetaldehyde, and phenylacetaldehyde. Two potential pathways might be involved: 1. by inhibiting the content of precursors (glucose and creatinine), competing with the formation of amino acids, to suppress HCAs generation; 2 through the removal of reactive carbonyl, reducing its reaction with creatinine.

The protective and therapeutic effects of agmatine on isoproterenol-induced myocardial injury in rats

Chronic inflammation and oxidative stress can contribute to the development of cardiovascular diseases. Isoproterenol (ISO), a synthetic catecholamine, is used to study the effects of drugs on cardiotoxicity. Agmatine (AGM) is a type of biogenic amine produced through the decarboxylation of arginine. The purpose of the current study was to evaluate the effects of AGM against ISO-induced cardiotoxicity due to the described roles of AGM in cardiovascular disease. Four groups of thirty-two Wistar Albino rats were divided equally as control, ISO, AGM+ISO, and ISO+AGM. ISO was administered intraperitoneally (i.p.) twice at a dose of 150 mg/kg, at 24-hour intervals. Prior to and after ISO injection, 20 mg/kg of AGM was injected i.p. Hemodynamic measurements and serum and tissue biochemical analyses were evaluated at the end of the experiment. The levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) in the tissue were measured. In the ISO group, levels of lactate dehydrogenase (LDH) and creatine kinase (CK) were increased significantly (p&lt;0.05). Co-administration of ISO and AGM significantly reduced CK and LDH levels (p&lt;0.05). MDA levels increased in the ISO-treated group but decreased in the AGM-treated groups (p&lt;0.05). Notably, there was a reduction in the CAT level in the ISO treatment group (p&lt;0.05). CAT was found to be significantly increased (p&lt;0.05) in the groups that received AGM compared to the ISO group. AGM+ISO group had a reduced density of degenerated cardiomyocytes and granulation tissue compared to the ISO group (p&lt;0.05). Although granulation tissue demonstrated a significant reduction in the ISO+AGM group in comparison to the ISO group (p&lt;0.05). In this study, the results indicate that AGM treatment can potentially inhibit ISO-induced myocardial injury and vascular dysfunction by preserving vascular integrity. Notably, the protective effects of AGM on cardiac damage appear to outweigh its therapeutic benefits, as shown by histopathological analysis