N-Acetylcysteine Amide(NACA) Reduces Cell Death after Oxidative Stress in a Porcine Embryonic Kidney Cell Line

Introduction: Oxidative stress may have detrimental effects on different structures of the cells, such as the DNA. Recently, we have published a study demonstrating that N-Acetylcysteine amide (NACA) displayed anti-inflammatory properties on the brain after exposure to oxidative stress in an established neonatal piglet model, imitating perinatal asphyxia. As different clinical studies have shown an association between the severity of hypoxic-ischemic encephalopathy and damage of the kidneys, we investigated a possible protective effect of NACA against H2O2-induced oxidative stress using a porcine epithelial-like embryonic kidney cell line (EFN-R). Objective: To investigate a potential protective effect of NACA on cells of a porcine embryonic kidney cell line exposed to H2O2. Methods: We subjected the cells to different concentrations of H2O2 for variable time periods, seeking the optimal dose-response for the experiments. Based on the results of these investigations, we exposed the cells to 100 μMol of H2O2 and/or 750 μM of NACA for 24 hours. Some of the cells would receive NACA either one hour before or one hour after exposure to H2O2. Results: The viability of the investigated EFN-R cells revealed that both, the group treated with NACA before exposure to H2O2 and the group treated with NACA after exposure to H2O2, exhibited significantly higher cell viability compared to the H2O2 group (p < 0.001 and p < 0.01, respectively). Discussion: The increased viability of the cells may indicate that NACA could play an important role in reducing oxidative stress. Taking the results from our previous study into consideration, our findings may strengthen the theory that NACA may have organ protective properties for neonates exposed to oxidative stress.

N-acetylcysteine amide protects against dexamethasone-induced cataract related changes in cultured rat lenses

Glucocorticoids (GCs) are one of the most widely used immunosuppressive and anti-inflammatory agents. However, their long term and systemic use is associated with adverse drug reactions including posterior subcapsular cataracts as one of its ocular complications. Balanced redox state is crucial for maintenance of lens transparency, and a high content of glutathione (GSH) in the lens is believed to play a key role in doing so. Depletion of GSH is implicated in the etiopathogenesis of dexamethasone-induced cataracts and, therefore, the present study was sought to evaluate the efficacy of a novel thiol antioxidant, N-acetylcysteine amide (NACA), in preventing dexamethasone-induced cataractogenesis. Cataract formation was induced by incubation of rat lenses with 5 μM dexamethasone. To assess whether NACA had a significant impact on dexamethasone-induced cataracts, the rat lenses were divided into four groups: 1) control group (Dulbecco’s Modified Eagle Medium (DMEM), 2) dexamethasone group (DMEM with 5 μM dexamethasone), 3) NACA-only group (50 μM NACA solution), and 4) NACA pretreatment group (50 μM NACA for 6 hours followed by 5 μM dexamethasone only for 18 hours). Lenses were cultured for 7 days at 37°C under 5% CO2. Lenses were evaluated daily using a dissecting microscope and photographed and graded for the development of opacity. The rat lenses in both the control and the NACA-only groups were clear, whereas all lenses within the dexamethasone-only group developed well-defined cataracts. Overall observations indicated that NACA inhibits cataract formation by limiting lipid peroxidation and increasing the ratio of GSH/GSSG in lens. Therefore, NACA can be developed into a potential adjunctive therapeutic option for patients undergoing therapy with GCs to inhibit glucocorticoid-induced cataracts.

Removal of Dye Using Lignin-Based Biochar/Poly(ester amide urethane)Nanocomposites from Contaminated Wastewater

The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discharge of synthetic dyes into wastewater has catalyzed the search for effective and sustainable treatment technologies.Among the various sorbent materials explored,biochar,being renewable,has gained prominence due to its excellent adsorption properties and environmental sustainability.It has also emerged as a focal point for its potential to replace other conventional reinforcing agents,viz.,fumed silica,aluminum oxide,treated clays,etc.This study introduces a novel class of polymer nanocomposites comprising of lignin-based biochar particles and poly(ester amide urethane)matrix via a feasible method.The structural evaluation of these nanocomposites was accomplished using Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,and powder X-ray diffraction.The polymer nanocomposites exhibited superior mechanical properties with an increment in tensile strength factor by 45%in comparison to its pristine matrix,along with an excellent toughness value of 90.22 MJm^(−3)at a low loading amount of only 1 wt%.The composites showed excellent improvement in thermal properties with a sharp rise in the glass transition temperature(Tg)value from−28.15℃to 84℃,while also championing sustainability through inherent biodegradability attributes.Beyond their structural prowess,these polymer nanocomposites demonstrated excellent potential as adsorbents,displaying efficient removal of malachite green and tartrazine dyes from aqueous systems with a removal efficiency of 87.25%and 73.98%,respectively.The kinetics study revealed the pseudo second order model to be the precision tool to assess the dye removal study.Complementing this,the Langmuir adsorption isotherm provided a framework to assess the sorption features of the polymer nanocomposites.Overall,these renewable biochar integrated polymer matrices boast remarkable recovery capabilities up to seven cycles of usage with an excellent dye recovery percentage of 95.21%for the last cycle,thereby defining sustainability as well as economic feasibility.

Effect of N-Acetylcysteine Combined with Lung Rehabilitation Therapy on Exercise Endurance and Quality of Life of Patients with Rheumatoid Arthritis-Related Interstitial Lung Disease

Objective:To explore the effect of N-acetylcysteine combined with lung rehabilitation therapy on exercise endurance and quality of life in patients with rheumatoid arthritis-related interstitial lung disease(RA-ILD).Methods:Fifty-six patients with RA-ILD admitted to Xijing Hospital from May 2022 to January 2024 were randomly divided into two groups:a non-rehabilitation group and a pulmonary rehabilitation group,with 28 patients in each group.Both groups received routine treatment.Additionally,the non-rehabilitation group received N-acetylcysteine treatment,while the lung rehabilitation group received lung rehabilitation treatment in addition to N-acetylcysteine.The improvement in exercise endurance and dyspnea between the two groups after treatment was compared and the quality of life of the patients was observed.Results:After treatment,the exercise endurance score in the lung rehabilitation group(335.67±45.29)was higher than that in the non-rehabilitation group(P<0.05).The dyspnea score in the lung rehabilitation group(0.72±0.16)was lower than that in the non-rehabilitation group(P<0.05).Additionally,FVC(3.18±0.58 L),FEV1(2.28±0.56 L),FEV1/FVC(69.69±5.56),and DLCO(60.53±5.92 mL/mmHg/min)were higher in the lung rehabilitation group compared to the non-rehabilitation group after treatment(P<0.05).Conclusion:Lung rehabilitation therapy combined with N-acetylcysteine treatment can effectively improve dyspnea symptoms,lung function,and exercise endurance in patients with RA-ILD.This approach helps to improve patient’s quality of life and is beneficial for their prognosis.

Antagonistic Effects of N-acetylcysteine on Mitogen-activated Protein Kinase Pathway Activation, Oxidative Stress and Inflammatory Responses in Rats with PM2.5 Induced Lung Injuries

Objective To evaluate the antagonistic effects of N-acetylcysteine(NAC)on mitogen-activated protein kinases(MAPK)pathway activation,oxidative stress and inflammatory responses in rats with lung injury induced by fine particulate matter(PM2.5).Methods Forty eight male Wistar rats were randomly divided into six groups:blank control group(C1),water drip control group(C2),PM2.5 exposed group(P),low-dose NAC treated and PM2.5 exposed group(L),middle-dose NAC treated and PM2.5 exposed group(M),and high-dose NAC treated and PM2.5 exposed group(H).PM2.5 suspension(7.5 mg/kg)was administered tracheally once a week for four times.NAC of 125 mg/kg,250 mg/kg and 500 mg/kg was delivered intragastrically to L,M and H group respectively by gavage(10 ml/kg)for six days before PM2.5 exposure.The histopathological changes and human mucin 5 subtype AC(MUC5AC)content in lung tissue of rats were evaluated.We investigated IL-6 in serum and bronchoalveolar lavage fluid(BALF)by Enzyme-linked immunosorbent assay(ELISA),MUC5AC in lung tissue homogenate by ELISA,glutathione peroxidase(GSH-PX)in serum and BALF by spectrophotometry,and the expression of p-ERK1/2,p-JNK1/2 and p-p38 proteins by Western blot.All the measurements were analyzed and compared statistically.Results Lung tissue of rats exposed to PM2.5 showed histological destruction and increased mucus secretion of bronchial epithelial cells.Rats receiving NAC treatment showed less histological destruction and mucus secretion.Of P,L,M and H group,MUC5AC in lung tissue,IL-6 in serum and BALF were higher than controls(C1 and C2)(all P<0.05),with the highest levels found in the P group and a decreasing trend with increase of NAC dose.The activity of GSH-PX in serum and BALF of PM2.5 exposed rats(P,L,M and H)was lower than that of controls(all P<0.05),with higher activities found in NAC treated rats(L,M,and H),and an increasing trend with increase of NAC dose.The expressions of p-ERK1/2,p-JNK1/2 and p-p38 proteins in PM2.5 exposed lung tissue(P,L,M and H)was higher than controls(all P<0.05),with decreased levels and dose dependent downregulation found in NAC treated rats.Conclusion NAC can antagonize major MAPK pathway activation,lung oxidative stress and inflammatory injury induced by PM2.5 in rats.

大位阻氨基酸Fmoc-Arg(Pbf)-OH与Rink Amide-AM树脂的高效缩合

采用集自动搅拌、过滤、鼓泡等多重功能于一体的自制多肽固相合成反应器,以对称酸酐法、活化酯法、2,6-二氯苯甲酰氯(DCB)法研究了大位阻氨基酸Fmoc-Arg(Pbf)-OH与Rink Amide-AM树脂的连接反应工艺。探讨了催化体系、溶剂体系、反应时间、反应物配比以及搅拌方式对合成Fmoc-Arg(Pbf)-Rink Amide-AM树脂反应的影响。结果表明,采用活化酯法(DIC/HOBt/DMAP)时连接率最高,最佳反应条件为:在采用N2辅助磁力拌系统,以体积比为1∶1的DMA/DCM为反应溶剂,氨基酸与树脂物质的量的比为3∶1,反应时间为3 h时,连接率高达93%。

天然产物Trichodermamide类似物的合成

以8a-甲氧基-4,4a,5,8-四氢-1,2-苯并口恶嗪-3-羧酸乙酯(1a)为起始原料,经NaOH醇溶液和酸处理,在4-pyrrolidinopyridine和碳化双(环己基亚胺)(DCC)的存在下与3-氨基-7,8-二甲氧基香豆素(2)进行了酰胺化反应,合成了天然产物Trichodermamides的类似物T-1,总收率为61.6%,T-1通过了1HNMR,13CNMR,IR和元素分析等光谱学的结构表征;同时水解反应研究发现,含苯并口恶嗪双环结构的化合物1a可水解脱去酯基,而口恶嗪双环8a位上连有两个O的缩酮类似结构可稳定地保留。

Research Status of Amide Herbicides and Their Safeners

The widespread use of chemical herbicides especially amide herbicides has promoted the innovation of chemical weeding in farmland, but amide herbicides have brought invisible chemical injuries to crops in addition to weeding. Herbi-cidesafeners should be applied at the same time with herbicides to ensure herbi- cides will not injure crops while controlling weeds. The research and application of safeners is of great significance to resolving or alleviating the negative effects of herbicides on crop growth. The overview, mechanism, applied research progress and existing problems of amide herbicides and their safenars are summarized.

In situ Detection of Amide A Bands of Proteins in Water by Raman Ratio Spectrum

The amide A band of protein is sensitive to the hydrogen bands of amide groups of proteins. However, it is hard to distinguish the amide A band of aqueous protein in situ directly, since it overlaps with O-H stretching vibration of water. In this work, we presented a new analytical method of Raman ratio spectrum, which can extract the amide A band of proteins in water. To obtain the Raman ratio spectrum, the Raman spectrum of aqueous protein was divided by that of pure water. A mathematical simulation was employed to examine whether Raman ratio spectrum is effective. Two kinds of protein, lysozyme and （^-chymotrypsin were employed. The amide A bands of them in water were extracted from Raman ratio spectra. Additionally, the process of thermal denaturation of lysozyme was detected from Raman ratio spectrum. These results demonstrated the Raman ratio spectra could be employed to study the amide A modes of proteins in water.

Amide-AlCl_(3)类离子液体催化苯与苯酐酰基化反应

采用催化剂筛选和单因素实验及红外光谱、紫外光谱、拉曼光谱等表征手段,对Amide-AlCl_(3)类离子液体催化苯与苯酐(PHA)酰基化合成邻苯甲酰苯甲酸(BBA)的反应性能及机理进行了研究。结果表明,类离子液体N,N-二甲基乙酰胺-2AlCl_(3)(DMA-2AlCl_(3))为苯与苯酐酰基化反应的较优催化剂,其制备条件为n(AlCl_(3))∶n(DMA)=2∶1、100℃下反应3 h。DMA-2AlCl_(3)催化合成BBA反应的较优条件为n(Benzene)∶n(DMA-2AlCl_(3))∶n(PHA)=10∶2∶1、40℃、反应5 h,该条件下BBA收率达98.2%。DMA-2AlCl_(3)催化苯与苯酐酰基化反应机理为:DMA-2AlCl_(3)中的Al_(2)Cl_(7)^(-)进攻苯酐中的醚键氧及一个羰基氧得到酰基正离子;DMA-2AlCl_(3)中的[AlCl_(2)·n(DMA)]^(+)与苯环的π-环电子相互作用,使苯环上的π电子活化;酰基正离子作为亲电试剂进攻活化的苯环大π键,从而完成亲电取代反应生成BBA。

L-theanine: A potential multifaceted natural bioactive amide as health supplement

Natural bioactive compounds from plants are of great importance in modern therapeutics,which are used to prepare antibiotics, growth supplements or some other therapeutics. Ltheanine is such a bioactive amide amino acid presented in different plants and fungi,especially in tea. Theanine has influential effects on lifestyle associated diseases, such as diabetes, cardiovascular disorders, hypertension, stress relief, tumor suppression,menstruation and liver injury. This amino acid can maintain normal sleep and improve memory function and nullify effect of the neurotoxins. The rate of bioavailability and its medium of ingestion in the body is one of the great concerns for its additional antioxidant properties. Pharmacokinetics of the bioactive compound and its mode of action are described herewith. The biosynthesis and industrial synthesis are also reviewed to promote accelerated production of this bioactive compound in the pharmaceutical industries.

Synthesis and Anti-tumor Activity of Novel Amide Derivatives of Ursolic Acid

Ursolic acid was modified at C3 and C28 position to obtain fourteen derivatives including twelve novel compounds, and their chemical structures were characterized by IR, ^1H NMR and MS. Cell growth inhibitory effects of the derivatives against Hela cell were evaluated by MTT assay. All these derivatives were found to have stronger cell growth inhibitory than their parent compound, ursolic acid. The derivatives with a substituted acetyl group at C3 hydroxyl group show better activities than those with an unsubstituted hydroxyl group.

Synthesis of 2, 6-(substituded)pyridine Derivatives Using Amide and Imine Groups

A new wo-armed?acyclic diamide Ia 2, 6-bis(1-ethanecarbozamido-2-amino)pyridine, and a new series of aromatic aldehyde schiff bases containing pyridine ring and amide bridge, IIa-f, were prepared. The compounds were characterized by elemental analysis, IR, 1HNMR and MS. The bioactivity half inhibitory concentration C1/2 is given.

Premedication with pronase or N-acetylcysteine improves visibility during gastroendoscopy: An endoscopist-blinded, prospective, randomized study

AIM： To assess the efficacy of premedicaton with pronase or N-acetylcysteine （NAC） at 20 min before upper gastrointestinal （UGI） endoscopy and to determine whether pronase or NAC pretreatment influences the reliability of the rapid urease test. METHODS： A total of 146 patients were prospectively and randomly assigned into the study groups according to different premedications before endoscopy. One endoscopist assessed mucosal visibility （MV） with scores ranged from 1 to 4 at four sites in the stomach. The sum of the MV scores from these four locations was defined as the total mucosal visibility （TMV） score. Identification of Hpylori was performed using CLO test, histology, and serology. RESULTS： The Group with pronase premedication had a significantly lower TMV score than did the groups with gascon and gascon water （P 〈 0.001 and P 〈 0.01, respectively）. The group with NAC had a significantly lower TMV score than the group with gascon （P 〈 0.01） and a trend of a lower MV score than the group with gascon water （P = 0.06）. The THV score did not significantly differ between the group with pronase and the group with NAC （P = 0.39 and P = 0.14, respectively）. The sensitivity and specifidty of the CLO test were 92.5% and 93.9%, respectively, in groups premedicated with pronase and NAC together.CONCLUSION： Premedication with pronase or NAC at 20 min before UGI endoscopy improves the mucosal visibility of the stomach. Neither pronase nor NAC produces any obvious interference with the CLO test for the identification of H pylori infection.

Efficacy of premedication with activated Dimethicone or N-acetylcysteine in improving visibility during upper endoscopy

AIM:To assess the efficacy of N-acetylcysteine(NAC) and activated Dimethicone in improving endoscopic mucosal visibility.METHODS:A total of 148 patients were randomly allocated into four groups to receive one of the following premedications:group A:100 mL water alone;group B:activated Dimethicone plus water(up to 100 mL);group C:NAC plus water(up to 100 mL);and group D:activated Dimethicone and NAC plus water(up to 100 mL).A single endoscopist blinded to the patients group assessed the gastric mucosal visibility scores(range 1-4) at four sites.The sum of the scores from the four sites was considered as the total mucosal visibility score(TMVS).RESULTS:The patients in group B showed a significantly lower TMVS than those of groups A and C(P < 0.001).The TMVS in patients of group D was significantly lower than that of groups A and C(P < 0.001).The TMVS did not significantly differ between groups B and D(P > 0.05).The difference between TMVS of groups C and A was not significant(P > 0.05).CONCLUSION:Premedication with activated Dimethicone 20 min prior to the upper endoscopy leads to the best visibility.NAC does not improve visualization by itself.

N-acetylcysteine inhibits activation of toll-like receptor 2 and 4 gene expression in the liver and lung after partial hepatic ischemia-reperfusion injury in mice

BACKGROUND: Toll-like receptor 2 and 4 (TLR2/4) may play important roles in ischemia-reperfusion (I/R) injury, and N-acetylcysteine (NAC) can prevent the generation of reactive oxygen species (ROS) induced by I/R injury. This study aimed to investigate the changes in TLR2/4 gene expression in the liver and lung after I/R injury with or without NAC pretreatment. METHODS: BALB/c mice were used in a model of partial hepatic I/R injury and randomly assigned to a sham-operated control group (SH), a hepatic ischemia/reperfusion group (I/R) or a NAC pretreated, hepatic I/R group (I/R-NAC). The levels of TNF-alpha in the portal vein and plasma alanine aminotransferase (ALT) were measured at 1 and 3 hours after reperfusion. The lung wet-to-dry ratio was measured, and the expression of TLR2/4 mRNA and protein in the liver and lung were assessed with RT-PCR and Western blotting at the same time points. RESULTS: Compared with the I/R group, the expression of TLR2/4 mRNA and protein in the liver and lung in the I/R-NAC group was decreased at the same time point (P<0.05). The levels of portal vein TNF-a and plasma ALT increased continuously in the l/R group at I and 3 hours of reperfusion compared with the SH group; however, they declined significantly in the group pretreated with NAC (P<0.05). The extent of lung edema was relieved in the I/R-NAC group compared with the I/R group (P<0.05). CONCLUSIONS: TLR2/4 was activated in the liver and lung in the process of partial hepatic I/R injury. NAC inhibited the activation of TLR2/4 and the induction of TNF-alpha resulting from I/R injury via modulating the redox state, thus it may mitigate liver and lung injury following partial hepatic I/R in mice.

N-acetylcysteine does not prevent post-endoscopic retrograde cholangiopancreatography hyperamylasemia and acute pancreatitis

AIM： Acute pancreatitis （AP） is the most common and often severe complication of endoscopic retrograde cholangiopancreatography （ERCP）. The early step in the pathogenesis of acute pancreatitis is probably the capillary endothelial injury mediated by oxygen-derived free radicals. N-acetylcysteine - a free radical scavenger may be potentially effective in preventing post-ERCP acute pancreatitis and it is also known that N-acetylcysteine （ACC） can reduce the severity of disease in experimental model of AP. METHODS： One hundred and six patients were randomly allocated to two groups. Fifty-five patients were given N-acetylcysteine （two 600 mg doses orally 24 and 12 h before ERCP and 600 mg was given iv, twice a day for two days after the ERCP）. The control group consisted of 51 patients who were given iv. isotonic saline twice a day for two days after the ERCP. Serum and urine amylase activities were measured before ERCP and 8 and 24 h after the procedure. The primary outcome parameter was post-ERCP acute pancreatitis and the secondary outcome parameters were differences between groups in serum and urine amylase activity. RESULTS： There were no significant differences in the rate of post-ERCP pancreatitis between two groups （10 patients overall, 4 in the ACC group and 6 in the controlgroup）. There were also no significant differences in baseline and post-ERCP serum and urine amylase activity between ACC group and control group. CONCLUSION： N-acetylcysteine fails to demonstrate any significant preventive effect on post-ERCP pancreatitis, as well as on serum and urine amylase activity.

Measurement and Correlation for Solubility of (S)-(+)-2,2-Dimethyl-cyclopropane Carbox Amide in Different Solvents

(S)-(+)-2,2-dimethylcyclopropane carbox amide is a key intermediate of Cilastatin, an inhibitor of de- hydropeptidase-I. Its corresponding solid-liquid equilibrium data will provide essential support for industrial design and further theoretical studies. The solubilities of (S)-(+)-2,2-dimethylcyclopropane carbox amide in toluene, di- chloromethane, trichloromethane, ethyl acetate, ethanol and pure water at different temperature were measured us- ing the synthetic method by a laser monitoring observation technique. The solubility data were correlated with the modified Apelblat equation. The calculated values were good in agreement with the experimental values.

Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, ~ 1H NMR, \{~ ~13 C NMR\} and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.

Amide Ionic Liquids(AILs)/L-Proline Synergistic Catalyzed Asymmetric Mannich Reactions

Amide ionic liquids （MLs）/L-proline synergistic catalyzed Mannich reactions of isovaleraldehyde, methyl ketones, and aromatic amines were carried out in moderate to high yields （ up to 96% ） and high stereo selectivities （ 〉99% e. e. ）. The products were easily isolated by extraction; and the catalyst system was readily recycled at least thrice without significant loss of efficiency. The scope of the substrates was studied and the interpretation of the manifest improvement of the reaction rates and enantio-selectivity of the novel catalyst system was speculated.