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.

N-acetylcysteine and reduced glutathione reverse flupirtine-induced liver injury and pro⁃duce other beneficial effects in combination with flupirtine

OBJECTIVE To assess whether N-acetylcysteine(NAC)and reduced glutathione(GSH)are effective in reversing flupirtine-induced hepatotoxicity and whether they have other beneficial effects when combined with flupirtine.METHODS The analgesic effects of NAC and flupirtine were first evaluated in carrageenaninduced inflammatory pain and paclitaxel-induced neuropathic pain.The combination subthreshold⁃ing approach was then used to determine whether the combination of NAC and flupirtine produced synergistic analgesic effects.Hepatotoxicity markers and histopathological examination of the liver were used to assess the efficacy of NAC and GSH in reversing flupirtine-induced hepato⁃toxicity.Finally,the effect of GSH on the safe range of flupirtine was assessed in an acute tox⁃icity assay.RESULTS Flupirtine and NAC pro⁃duced dose-dependent antiallodynic effects evoked by carrageenan and paclitaxel in mice.In the above model,the combination of NAC and flupirtine produced an unexpected synergistic analgesic effect.There were no significant differ⁃ences observed in the hepatotoxicity markers and liver histopathology between the experimen⁃tal group and the control group under NAC and GSH treatment.Finally,GSH(200 mg·kg^(-1))expanded the therapeutic index of flupirtine by 1.77 times.CONCLUSION NAC and GSH are effective in preventing liver damage caused by long-term flupirtine use,which provides a solu⁃tion for the safe and effective treatment of chronic pain with flupirtine.In addition,the other benefi⁃cial effects of NAC and GSH when combined with flupirtine may provide the basis for the devel⁃opment of a new therapy with minimal sideeffects and good efficacy.

Effects of N-acetylcysteine on growth,viability and reactive oxygen species levels in small antral follicles cultured in vitro

Objective:To investigate the effects of different concentrations of N-acetylcysteine on follicular growth and morphology,as well as on viability,levels of reactive oxygen species(ROS)and meiotic progression of oocytes from in vitro cultured bovine early antral follicles.Methods:Isolated early antral follicles(about 500μm)were cultured in TCM-199+alone or supplemented with 1.0,5.0 or 25.0 mM N-acetylcysteine at 38.5℃with 5%CO_(2) for 8 days.Follicle diameters were evaluated at day 0,4 and 8 of culture.At the end of culture,the levels of ROS,chromatin configuration and viability(calcein-AM and ethidium homodimer-1 staining)were investigated in the cumulus-oocyte complexes.Comparisons of follicle diameters between treatments were performed.Data on percentages of morphologically normal follicles,growth rates and chromatin configuration in different treatments were compared.Results:An increase in follicular diameters after culture in all treatments was observed,except for follicles cultured with 25.0 mM N-acetylcysteine.Fluorescence microscopy showed that oocytes cultured in all treatments were stained positively with calcein AM,and that 5.0 mM N-acetylcysteine reduced fluorescence for ethidium homodimer-1.Intracellular levels of ROS in oocytes from follicles cultured with 1.0 mM N-acetylcysteine showed a significant reduction compared to other treatments.The presence of N-acetylcysteine in culture medium did not influence the rates of oocyte at the germinal vesicle stage.Conclusions:N-acetylcysteine at concentrations of 1.0 and 5.0 mM reduces ROS levels and staining for ethidium homodimer-1 in in vitro cultured follicles,respectively,while 25.0 mM N-acetylcysteine decreases follicular growth and the percentages of continuously growing follicles.

Preparation of Amide-Containing Insecticidal Derivatives from the Renewable Natural Productβ-Pinene

The preparation of bioactive derivatives from the renewable natural product pinene is a hot research topic in the deep processing and utilization of pinene.In this study,β-pinene was used to develop novel molecules as a promising new precursor of insecticide.A series of amide-containing derivatives ofβ-pinene were synthesized and characterized.The insecticidal activities of these derivatives against Mythimna separate and Semiaphis heraclei were tested.The structure characterization results showed that the characterization data of amide-containing derivatives were in full agreement with their proposed structures.The insecticidal activities evaluation results indicated that amide-containing derivatives exhibited weak insecticidal activity against Mythimna separate,but exhibited moderate to good insecticidal activity against Semiaphis heraclei.After testing for 72 h,the corrected mortality against Semiaphis heraclei of compounds 5c,5e,5f,5 h,5j,and 5 m was 100%at 1000 mg/L.The structure-activity relationship analysis results showed that the introduction of an amide group into the structure of derivatives improved their insecticidal activity against Semiaphis heraclei.Meanwhile,the amide-containing derivatives containing the F and NO_(2) substituted benzene ring might improve their insecticidal activity against Semiaphis heraclei.This study will be helpful for the high value-added utilization of the natural renewable resourceβ-pinene and the development of novel insecticides.

Methanolysis of amides under high-temperature and high-pressure conditions with a continuous tubular reactor

The methanolysis of amides,which is widely employed in the synthetic organic chemistry,hardly occurs under mild conditions.To safely and controllably intensify the methanolysis reaction with hightemperature and high-pressure environment,a continuous tubular reaction technology is developed,whose space-time yield is over twice of that of the conventional batch reaction.The methanolysis of acetanilide is selected as the representative reaction,and the influences of temperature,pressure,reactant and catalyst concentration,and residence time on the reaction performances are systematically investigated.Taking the advantages of precise temperature and reaction time control by the tubular reactor,the kinetics of acetanilide methanolysis are determined and compared to the kinetics of acetanilide hydrolysis reaction.The tubular reaction method is also employed to test a variety of other amides to show the effects of substituents,steric hindrance,and alkalinity on the reaction rate of methanolysis.

Amide proton transfer imaging of Alzheimer's disease and Parkinson's disease

Amide proton transfer (APT) magnetic resonance imaging (MRI) is an important molecularimaging technique at the protein level in tissue. Neurodegenerative diseases have a highlikelihood of causing abnormal protein accumulation in the brain, which can be detectedby APT MRI. This article briefly introduces the principles and image processing technologyof APT MRI, and reviews the current state of research on Alzheimer's disease and Parkinson's disease using this technique. Early applications of this approach in these twoneurodegenerative diseases are encouraging, which also suggests continued technicaldevelopment and larger clinical trials to gauge the value of this technique.

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。

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.

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。

N-acetylcysteine attenuates reactive-oxygen-speciesmediated endoplasmic reticulum stress during liver ischemia-reperfusion injury

AIM:To investigate the effects of N-acetylcysteine(NAC) on endoplasmic reticulum(ER) stress and tissue injury during liver ischemia reperfusion injury(IRI).METHODS:Mice were injected with NAC(300 mg/kg) intraperitoneally 2 h before ischemia.Real-time polymerase chain reaction and western blotting determined ER stress molecules(GRP78,ATF4 and CHOP).To analyze the role of NAC in reactive oxygen species(ROS)-mediated ER stress and apoptosis,lactate dehydrogenase(LDH) was examined in cultured hepatocytes treated by H2O2 or thapsigargin(TG).RESULTS:NAC treatment significantly reduced the level of ROS and attenuated ROS-induced liver injury after IRI,based on glutathione,malondialdehyde,serum alanine aminotransferase levels,and histopathology.ROS-mediated ER stress was significantly inhibited in NAC-treated mice.In addition,NAC treatment significantly reduced caspase-3 activity and apoptosis after reperfusion,which correlated with the protein expression of Bcl-2 and Bcl-xl.Similarly,NAC treatment significantly inhibited LDH release from hepatocytes treated by H2O2 or TG.CONCLUSION:This study provides new evidence for the protective effects of NAC treatment on hepatocytes during IRI.Through inhibition of ROS-mediated ER stress,NAC may be critical to inhibit the ER-stressrelated apoptosis pathway.

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.

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.

Synthesis of Novel Poly(aryl ether amide)s Containing the Phthalazinone Moiety

Two novel heterocyclic diamine monomers: 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl] (2H)phthalazin-1-one and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-3,5-dimethylphenyl](2H)phthalazin-1-one were successfully synthesized from readily available heterocyclic bisphenol-like monomers in two steps in high yield. A series of novel poly(aryl ether amide)s containing the phthalazinone moiety were successfully prepared by the direct polymerization of the novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents.

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.

N-acetylcysteine treats intravenous amiodarone induced liver injury

We report a case of intravenous(IV) amiodarone drug induced liver injury(DILI).The patient received IV N-acetylcysteine(NAC) which resulted in a rapid improvement in liver enzymes.While the specific mechanisms for the pathogenesis of IV amiodaroneDILI and the therapeutic action of IV NAC are both unknown, this case strongly implies at least some commonality.Because IV amiodarone is indicated for the treatment of serious cardiac arrhythmias in an intensive care unit setting, some degree of ischemic hepatitis is likely a cofactor in most cases.