A perspective on recent findings and future strategies for reactive aldehyde removal in spinal cord injury

Acrolein in spinal cord injury:The propensity of reactive aldehydes such as acrolein to both initiate and perpetuate tissue damage after spinal cord injury (SCI) is well established.Formed primarily from lipid peroxidation,acrolein is known to be one of the most reactive aldehydes.Acrolein will quickly overwhelm endogenous clearance mechanisms and antioxidants,and form adductswith lipids,proteins,and DNA.

Efficient electrooxidation of biomass-derived aldehydes over ultrathin Ni V-layered double hydroxides films

Selective upgrading of C=O bonds to afford carboxylic acid is significant for the petrochemical industry and biomass utilization.Here we declared the efficient electrooxidation of biomass-derived aldehydes family over NiV-layered double hydroxides(LDHs) thin films.Mechanistic studies confirmed the hydroxyl active intermediate(-OH*) generated on the surface of NiV-LDHs films by employing electrochemical impedance spectroscopy and the electron paramagnetic resonance spectroscopy.By using advanced techniques,e.g.,extended X-ray absorption fine structure and high-angle annular dark-field scanning transmission electron microscopy,NiV-LDHs films with 2.6 nm could expose larger specific surface area.Taking benzaldehyde as a model,high current density of 200 mA cm^(-2)at 1.8 V vs.RHE,81.1% conversion,77.6% yield of benzoic acid and 90.8% Faradaic efficiency were reached,which was superior to most of previous studies.Theoretical DFT analysis was well matched with experimental findings and documented that NiV-LDHs had high adsorption capacity for the aldehydes to suppress the side reaction,and the aldehydes were oxidized by the electrophilic hydroxyl radicals formed on NiV-LDHs.Our findings offer a universal strategy for the robust upgrading of diverse biomass-derived platform chemicals.

Study on the catalytic degradation of sodium lignosulfonate to aromatic aldehydes over nano-CuO:Process optimization and reaction kinetics

As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective technology to convert lignin like sodium lignosulfonate(SL),a lignin derivative,into aromatic aldehydes such as vanillin and syringaldehyde.However,how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge,and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically.In this work,we adopted the stirred tank reactor(STR)for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde.The effect of operating conditions including reaction time,oxygen partial pressure,reaction temperature,SL concentration,rotational speed,catalyst amount,and NaOH concentration on the yield of single phenolic compound was systematically investigated.The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield.Therefore,they should be regulated in an optimal value to obtain high yield of these aldehydes.More importantly,the reaction kinetics of the lignin oxidation was explored.This work could provide basic data for the optimization and design of industrial operation of lignin oxidation.

Environment friendly protocol for the synthesis of nitriles from aldehydes

A rapid and eco-friendly one-pot protocol for the synthesis of nitriles has been developed by treating various araldehydes bearing electron withdrawing as well as electron donating groups with hydroxylamine hydrochloride in the presence of non-toxic,non-corrosive and reusable zinc oxide（ZnO） as the catalyst under solvent-free microwave irradiation.The present approach offers the advantages of a clean reaction,simple methodology,employing readily available catalyst,short reaction duration（〈1 min）,high selectivity;and high yield（90-98%）.

A Facile Synthesis of β-Cyclodextrin Monoaldehyde

β -Cyclodextrin (β -CD) was directly oxidized in high yield to the corresponding monoaldehyde by cyclized 2-iodoxybenzoic acid (IBX) in DMSO.

Ferrous methanesulfonate as an efficient and recyclable catalyst for chemoselective synthesis of 1,1-diacetate from aldehydes

Ferrous methanesulfonate catalysing the conversion of aromatic, heteroaromatic, unsaturated, and aliphatic aldehydes to 1,1- diacetates at room temperature under solvent-free condition has been developed. The catalytic activity of seventeen metal methanesulfonates was compared under the same condition, ferrous methanesufonate proved to be the best. It can be easily recovered and reused for several times without distinct deterioration in catalytic activity. During the competitive protection between a ketone and an aldehyde group with Ac20, 1,1-diacetate formed exclusively with the aldehyde group. 2009 Min Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

β-Cyclodextrin promoted oxidation of aldehydes to carboxylic acids in water

A facile, efficient and substrate-selective oxidation of aldehydes to carboxylic acids with NaClO catalyzed by β-cyclodextrin in water has been developed. A series of aldehydes which could form inclusion complex with β-cyclodextrin （β-CD） were oxidized selectively with excellent yields.

Role of aldehyde dehydrogenase 2 in ischemia reperfusion injury:An update

Aldehyde dehydrogenase 2(ALDH2) is best known for its critical detoxifying role in liver alcohol metabolism. However, ALDH2 dysfunction is also involved in a wide range of human pathophysiological situations and is associated with complications such as cardiovascular diseases, diabetes mellitus, neurodegenerative diseases and aging. A growing body of research has shown that ALDH2 provides important protection against oxidative stress and the subsequent loading of toxic aldehydes such as 4-hydroxy-2-nonenal and adducts that occur in human diseases, including ischemia reperfusion injury(IRI). There is increasing evidence of its role in IRI pathophysiology in organs such as heart, brain, small intestine and kidney; however, surprisingly few studies have been carried out in the liver, where ALDH2 is found in abundance. This study reviews the role of ALDH2 in modulating the pathways involved in the pathophysiology of IRI associated with oxidative stress, autophagy and apoptosis. Special emphasis is placed on the role of ALDH2 in different organs, on therapeutic "preconditioning" strategies, and on the use of ALDH2 agonists such as Alda-1, which may become a useful therapeutic tool for preventing the deleterious effects of IRI in organ transplantation.

An Efficient and Green Procedure for the Preparation of gem-Dicar- boxylates from Aldehydes Catalyzed by Fe_2(SO_4)_3·xH_2O

An efficient and environmentally benign conversion of aldehydes into the corresponding gem-dicarboxylates was realized by using hydrated ferric sulfate as a heterogeneous catalyst. In addition to its high efficiency, the catalyst can be recovered simply and reused efficiently for at least seven times.

Sulfonated carbon catalyzed oxidation of aldehydes to carboxylic acids by hydrogen peroxide

Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via the carbonization of starch followed by sulfonation with concentrated sulfuric acid. N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence and acid-base titration were used to characterize the obtained materials. The catalytic activity of sulfonated carbon was studied in the oxidation of aldehydes to carboxylic acids using 30 wt% H2O2 as oxidant. This oxidation protocol works well for various aldehydes including aromatic and aliphatic aldehydes. The sulfonated carbon can be recycled for three times without obvious loss of activity.

A simple and efficient method for solvent-free iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid by grinding method

Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.

A New Brominated Phenylpropylaldehyde and its Dimethyl Acetal from Red Alga Rhodomela confervoides

A new brominated phenylpropylaldehyde and its dimethyl acetal together with a new natural brominated phenol were isolated from Rhodomela confervoides. Their structrues were elucidated as 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde, 2-methyl-3-(2,3-di-bromo-4,5-dihydroxyphenyl) propylaldehyde dimethyl acetal and 3-bromo-4,5-dihydroxybenzoic acid methyl ester by spectroscopic techniques including IR, HRFABMS, ID and 2DNMR experiments.

Aldehyde dehydrogenase 2 overexpression inhibits neuronal apoptosis after spinal cord ischemia/reperfusion injury

Aldehyde dehydrogenase 2（ALDH2）is an important factor in inhibiting oxidative stress and has been shown to protect against renal ischemia/reperfusion injury.Therefore,we hypothesized that ALDH_2 could reduce spinal cord ischemia/reperfusion injury.Spinal cord ischemia/reperfusion injury was induced in rats using the modified Zivin＇s method of clamping the abdominal aorta.After successful model establishment,the agonist group was administered a daily consumption of 2.5%alcohol.At 7 days post-surgery,the Basso,Beattie,and Bresnahan score significantly increased in the agonist group compared with the spinal cord ischemia/reperfusion injury group.ALDH_2expression also significantly increased and the number of apoptotic cells significantly decreased in the agonist group than in the spinal cord ischemia/reperfusion injury group.Correlation analysis revealed that ALDH_2 expression negatively correlated with the percentage of TUNEL-positive cells（r=-0.485,P〈0.01）.In summary,increased ALDH_2 expression protected the rat spinal cord against ischemia/reperfusion injury by inhibiting apoptosis.

Aerobic oxidation of benzylic aldehydes to acids catalyzed by iron (Ⅲ) meso-tetraphenylporphyrin chloride under ambient conditions

Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron （Ⅲ） meso-tetrapbenylporphyrin chloride （Fe（TPP）Cl） under ambient conditions was developed. The catalyst has been proved to be an excellent catalyst for the system in the presence of molecular oxygen and isobutryaldehyde at room temperature.

Association of genetic polymorphisms of aldehyde dehydrogenase-2 with esophageal squamous cell dysplasia

AIM:To demonstrate the possible associations between genetic polymorphisms of aldehyde dehydrogenase-2(ALDH2) and esophageal squamous cell dysplasia(ESCD).METHODS:All participants came from an area of high incidence of esophageal cancer and underwent an endoscopic staining examination;biopsies were taken from a non-staining area of the mucosa and diagnosed by histopathology.Based on the examinations,the subjects were divided into the control group with normal esophageal squamous epithelial cells and the ESCD group.ALDH2 genotypes of 396 cases were determined including 184 ESCD cases and 212 controls.The odds ratio(OR) and 95% confidence intervals(95% CI) were calculated by binary logistic regression models.RESULTS:The distribution of ALDH2 genotypes showed significant differences between the two groups.The adjustment factors were gender and age in the logistic regression models.Compared with 2*2/2*2 genotype,2*1/2*1 genotype was found to be a risk factor for ESCD,and the OR(95% CI) was 4.50(2.21-9.19).There were significant correlations between ALDH2 genotypes and alcohol drinking/smoking/history of esophageal cancer.CONCLUSION:The ALDH2 polymorphism is significantly associated with ESCD.

Iodine-catalyzed Efficient Synthesis of β-Keto Esters from Aldehydes and Ethyl Diazoacetate Under Solvent-free Conditions

An efficient procedure for the synthesis ofβ-keto esters from the reaction of aldehydes and ethyl diazoacetate catalyzed by iodine at room temperature under solvent-free conditions has been described. The catalytic procedure has the advantages of easily available catalyst, mild reaction conditions, high yields, and easy work-up.

Acetic acid assisted cobalt methanesulfonate catalysed chemoselective diacetylation of aldehydes

Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and reused many times. The reaction was mild and efficient with good to high yields.