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It is commonly known that aldehyde dehydrogenases (ALDHs) are a promising therapeutic target in many diseases. Bui et al.--the authors of the paper I am discussing here (Biosci Rep (2021) 41(5): BSR20210491 https://doi.org/10.1042/BSR20210491)--point that there is a lack of research on the use of spices and herbs as the sources of naturally occurring modulators of ALDH activity. In order to carry out this type of research, the authors prepared ethanolic extracts of 22 spices and herbs. The main objective of the study was to investigate retinaldehyde dehydrogenases (RALDHs), of which retinal is the main substrate and ALDH2, the mitochondrial isoform, having acetaldehyde as the main substrate. The obtained results indicated that the tested extracts exhibited differential regulatory effects on RALDHs/ALDH2 and some of them showed a potential selective inhibition of the activity of RALDHs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gentle power of laser was used to do surface modification of paper substrates. • Effects of different types of lasers including CWL, NS, and FS were studies. • Physical and chemical changes of laser-ablated paper were investigated. • Aldehydes were produced by laser ablation and raised the paper's chemical reactivity. • Aldehydes-related color chemical reactions were performed with acoustofluidic PADs. Paper-based analytical devices (PADs) have rapidly thrived in the last decade for their easy operation and rapid response. However, because of its low chemical reactivity, it's still challenging to endow the paper substrate with more functions and expand its application field. Here, this work leverages lasers to do surface modifications of paper to raise its chemical reactivity. A gentle power of laser was utilized to ablate a part thickness of the paper. The effect of laser types was studied, including continuous-wave, nanosecond, and femtosecond lasers. Continuous-wave laser caused severe photothermal effects and produced more pyrolytic oil. The physical changes including mechanical strength and fluid wicking were studied. The chemical changes were analyzed by XPS and FTIR. Because of the produced aldehydes by laser ablation, the laser-modified papers were endowed with more functions and we experimented with aldehyde-related color reactions on them, which might promote the color printing industry. In addition, to fully exploit the produced aldehydes, our recently developed acoustofluidic PADs were employed for flow intensification and homogeneous mixing. This work demonstrates an economical and effective method for a new type of functional paper substrates which holds potential for various fields. [ABSTRACT FROM AUTHOR]

It has been reported that the modification of immobilized glyoxyl–ficin with aldehyde dextran can promote steric hindrances that greatly reduce the activity of the immobilized protease against hemoglobin, while the protease still maintained a reasonable level of activity against casein. In this paper, we studied if this effect may be different depending on the amount of ficin loaded on the support. For this purpose, both the moderately loaded and the overloaded glyoxyl–ficin biocatalysts were prepared and modified with aldehyde dextran. While the moderately loaded biocatalyst had a significantly reduced activity, mainly against hemoglobin, the activity of the overloaded biocatalyst was almost maintained. This suggests that aldehyde dextran was able to modify areas of the moderately loaded enzyme that were not available when the enzyme was overloaded. This modification promoted a significant increase in biocatalyst stability for both biocatalysts, but the stability was higher for the overloaded biocatalyst (perhaps due to a combination of inter- and intramolecular crosslinking). [ABSTRACT FROM AUTHOR]

A facile route for the large scale production of graphene oxide (GO) papers and their mechanical enhancement has been presented in this work. The novel paper-like GO made from individual GO sheets in aqueous suspension can be achieved in large scale by a simple drop casting method on hydrophobic substrates. Significant enhancement in mechanical stiffness (341%) and fracture strength (234%) of GO paper have been achieved upon modification with a small amount (less than 10 wt%) of glutaraldehyde (GA). The cross-linking reaction takes place between hydroxyl groups on the surface of GO and aldehyde groups of GA, through forming hemiacetal structure, which can result in distinct mechanical enhancement of the GO papers. [ABSTRACT FROM AUTHOR]

Highlights: [•] Direct analysis by paper spray, without sample preparation. [•] In situ derivatization and identification of dialdehydic species. [•] Evaluation of anti-inflammatory active principles. [ABSTRACT FROM AUTHOR]

A method for the reduction of aldehydes with pinacolborane catalyzed by pincer cobalt complexes based on a triazine backbone is developed in this paper. The presented methodology allows for the transformation of several aldehydes bearing a wide range of electron-withdrawing and electron-donating groups under mild conditions. The presented procedure allows for the direct one-step hydrolysis of the obtained intermediates to the corresponding primary alcohols. A plausible reaction mechanism is proposed. [ABSTRACT FROM AUTHOR]

In situ synthesis of gold nanoparticles on paper sheets was achieved without any external reducing reagents and heat treatments. Surface-activated pulp fibers with carboxyl and aldehyde contents of 1.18 and 0.349 mmol g-1, respectively, which were obtained from softwood kraft pulp using 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), were fabricated into paper sheets with polyamideamine epichlorohydrin (PAE) resin with a papermaking technique. The TEMPO-oxidized pulp papers were flexible, lightweight, and easy to handle in a wet state due to the PAE-mediated reinforcement. Simple immersion of the white TEMPO-oxidized paper in an aqueous solution of tetrachloroauric acid at room temperature brought about distinct color change from white to red-purple, strongly suggesting the formation of gold nanoparticles. Post-oxidized aldehyde-free paper provided no color variation, and thus the aldehyde groups on pulp fibers made a significant contribution to the in situ synthesis of gold nanoparticles. The organic-inorganic paper materials of TEMPO-oxidized pulp and gold nanoparticles demonstrated the catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol in an aqueous system. [ABSTRACT FROM AUTHOR]

The effects of moisture, oxygen, and acidity upon the aging of Kraft and thermally upgraded ("Insuldur®") papers have been studied in detail. The results for Kraft are consistent with the kinetic model and parameters proposed earlier by Emsley et al., and with the principle that moisture promotes acid-hydrolysis by causing carboxylic acids to dissociate. Moisture is released during the aging of Kraft and, hence, its aging is auto-acceleratory. In contrast, Insuldur consumed moisture under the same conditions, aged more slowly, and its aging was less accelerated by added moisture. 2-Furfuraldehyde (2FAL), which is a dehydration product of pentosans and, hence, an index of moisture production, is also released from Kraft during aging, but not from Insuldur. Acids are, however, produced from both types of paper. Theoretical explanations for these findings are proposed, and their practical implications for transformer maintenance are discussed. [ABSTRACT FROM AUTHOR]

An efficient and convenient method for the synthesis of 1-hydroxyalkylphosphonium salts is described. Reactions were carried out at room temperature, in a short time, and without chromatography for product isolation. The properties of the obtained phosphonium salts were examined and discussed. In this paper, primary attention was paid to the stability of phosphonium salts, depending on the structure of the aldehydes used as substrates in their preparation. Other conditions such as the type of solvent, temperature, and molar ratio of the substrates were also investigated. Finally, the high reactivity of 1-hydroxyalkylphosphonium salts was demonstrated in reactions with amide-type substrates and (hetero)aromatic compounds. The developed step-by-step procedure (with the isolation of 1-hydroxyphosphonium salts) was compared to the one-pot protocol (in situ formation of such phosphonium salts). [ABSTRACT FROM AUTHOR]

Cellulosic fibers were efficiently disintegrated from bamboo pulp as raw material and then oxidized using sodium periodate to introduce dialdehyde groups on their surfaces. The resultant fibers were characterized using Fourier transform infrared spectroscopy (FT-IR), Xray diffraction (XRD), and thermogravimetric analysis (TGA). FT-IR spectra demonstrated that the characteristic absorption band of aldehyde groups was present at 1735 cm-1, confirming that aldehyde groups were successfully introduced. XRD showed that the nature of bamboo pulp fibers changed slightly after oxidation, except in the reduction of crystallinity. The aldehyde content increased with the sodium periodate content and reached a maximum of 1.41 mmol/g. The yield loss maximum was 32.4 wt%. TGA results showed that the temperature at the initial and final decomposition of the oxidized fibers was subject to the periodate dosage and that the thermal stability decreased to some extent. [ABSTRACT FROM AUTHOR]

Lipid peroxidation, the most aggressive reaction in food, results in the formation of reactive organic compounds that detrimentally impact food sensory qualities and consumers' health. While controlled lipid peroxidation can enhance flavors and appearance in certain foods, secondary peroxidation products lead to sensory deterioration in a variety of products, such as oils, alcoholic beverages, and meat. This publication reviews the use of modern analytical techniques for detecting and quantifying carbonyl compounds, i.e., secondary lipid peroxidation products. The paper focuses specifically on microextraction-based methods: dispersive liquid-liquid microextraction (DLLME), solid-phase microextraction (SPME), and gas-diffusion microextraction (GDME). These techniques offer efficient and sensitive approaches to extracting and quantifying lipid oxidation products and contribute to the understanding of oxidative deterioration in various food products. The review outlines recent advancements, challenges, and limitations in these microextraction techniques, as well as emphasizes the potential for further innovation and improvement in the field of food analysis. [ABSTRACT FROM AUTHOR]

Hydrogenation of aldehydes with heterogeneous manganese catalysts is an appealing approach for producing alcohols. In this paper, we report a novel and robust MnO/PN-800 catalyst for the hydrogenation of versatile biomass-derived platform molecules in the presence of molecular hydrogen as a reductant. The effect of catalyst concentration, the operating hydrogen pressure, and the reaction temperature on the catalyst activity was investigated in detail. Under the mild reaction conditions, the full conversion of furfuraldehyde, 5-Methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde (5-HMF) to their corresponding alcohols was achieved without any by-product formation. Additionally, other aromatic aldehydes bearing fluoro, chloro, and nitro moieties were also tolerated. The fresh and spent MnO/PN-800 catalyst was thoroughly characterized using XPS, powder-XRD, HR-TEM, N 2 adsorption-desorption, and Raman spectroscopy. Noteworthy, the MnO/PN-800 catalyst can be recovered by centrifugation and then reused directly in the subsequent hydrogenation reactions. Importantly the synthetic utility of this protocol up to ∼5 g-scale is realized. Finally, our novel MnO/PN-800 nanocatalyst was successfully employed for the direct synthesis of furfuryl alcohol in high yields from raw sugarcane bagasse. We believe that these findings will help to advance the manganese-catalyzed hydrogenation reactions. [Display omitted] • Waste biomass as a carbon support. • MnO/PN-800 as an efficient catalyst for hydrogenation of bio-based aldehydes. • Hydrogenation of FA, 5-MFA, and 5-HMF to their corresponding alcohols. • Synthesis of furfuryl alcohol from raw sugarcane biomass. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mild, clean and highly selective synthesis of amides under visible light and air as oxidants. • Inexpensive and readily available Mn 3 O 4 was used as a reusable photocatalyst. • Energy barrier for hemiaminal dehydrogenation is much lower than that of dehydration. • Mn 3 O 4 exhibited outstanding selectivity and efficiency in the synthesis of amides. Amides are widely used in various fields of chemical and pharmaceutical industries. Developing a green and universal amide synthesis method that meets the needs of sustainable chemistry has always been a challenge for amide synthesis. In this paper, a direct and highly selective method for the synthesis of amide was developed under visible light irradiation and room temperature using air as an oxidant. Thanks to the prolongation of the C-H bond (0.1115 nm) and O-H bond (0.1002 nm) during the adsorption of hemiaminal on the Mn 3 O 4 catalyst, and the energy barrier for hemiaminal dehydrogenation (-3.07 eV) is much lower than the energy barrier for dehydration (4.84 eV), thus the formation of imines is suppressed, resulting in highly selective clean production of amides with H 2 O as byproduct. Therefore, this clean and effective method for obtaining amides is one of the ideal alternative solutions for currently known methods. [ABSTRACT FROM AUTHOR]

Fingermarks and DNA are valuable traces in forensic investigations potentially allowing for the identification of the source of the trace or highlighting a link between a touched object and an individual. These traces are often latent and need to be detected before recovery. While a number of validated methods exist for fingermark detection, no routine method is in place for the detection of DNA. This study investigates the use of pdimethylaminobenzaldehyde (DMAB) in conjunction with indanedione zinc (IND-Zn) for the detection of latent cellular material and fingermarks on paper. The aim of this proof-of-concept study is to determine the successfulness of this reagent (DMAB-IND) in the detection of the respective traces and observe the impact it has on the resulting DNA profile. It was found that latent fingermarks and the associated cells could be visualised following treatment with the reagent. Samples treated with DMAB-IND showed a significantly higher percentage of alleles called compared to IND-Zn-treated and untreated samples due to the targeted recovery of cells. However, the reagent appears to degrade DNA at a rapid rate, requiring the treated samples to be processed for DNA on the day of treatment. [ABSTRACT FROM AUTHOR]

In this paper, DFT computations revealed the mechanisms of the asymmetric catalytic reactions of diisopropylzinc with pyrimidylaldehyde catalyzed by 1- and 2-aza[6]helicenes, which make them effective inductors of the autocatalytic chiral amplification Soai reaction. The generation of chirality takes place through the formation of adducts of aldehyde and helicenes stabilized via non-covalent disperse interactions strictly defining the orientation of the aldehyde molecule in the corresponding transition state. [ABSTRACT FROM AUTHOR]

The interaction of the important plasma protein, human serum albumin (HSA), with two monoterpenes found in cumin oil, i.e., cuminaldehyde (4-isopropylbenzaldehyde) and cuminol (4-isopropylbenzyl alcohol), was studied in this paper. Both experimental and computational methods were utilized to understand the mechanism of binding. The UV absorption profile of HSA changes in the presence of both cuminaldehyde and cuminol, due to the interaction between HSA with both monoterpenes. The intrinsic fluorescence intensity of HSA was also quenched on the sequential addition of both ligands, due to change in the microenvironment of the fluorophore present in the former. Quenching of HSA by cuminaldehyde was much higher in comparison to that in the presence of cuminol. Fluorescence quenching data were analyzed using modified Stern-Volmer and Lineweaver-Burk methods, which suggested that the binding mechanism was of a static type for both ligands. In both cases, the binding was favored by the domination of hydrophobic as well as hydrogen bonding/Van der Waals forces. Both ligands partially unfolded the secondary structure of HSA, although the effect of cuminaldehyde was more pronounced, as compared to cuminol. The preferred binding site of cuminaldehyde and cuminol inside HSA was also the same; namely, drug binding site 1, located in subdomain IIA. The study showed that cuminaldehyde binds strongly with albumin as compared to its alcohol counterpart, which is due to the more hydrophobic nature of the former. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of precursors on the formation of 3-MCPD esters (3-MCPD-E) and glycidol esters (GE) and discusses ways to reduce the concentration of these toxic esters in deodorised oils. As the content of oxidation products in sunflower oil increases, the amount of MCPD esters formed after deodorisation increases too: from 560 μg/kg (for oil with the peroxide value 1.06 mmol 1/2О/kg and the anisidine value 0.55) to 1290 μg/kg (for oil with PV=6.73 mmol 1/2O/kg and PAV=10.38). Thus, peroxides and aldehydes should be classified as the initiators of the formation of 3- MCPD-E. Accordingly, a way to reduce toxic 3-MCPD-E in deodorised oils is by preventing the formation of oxidation products during the extraction and processing of oils, or by reducing the content of oxidation products in oils before deodorisation. On the contrary, there is no correlation between the content of oxidation products and the amount of glycidol esters in deodorised oil. No relationship has been found between the content of natural antioxidants of oils, tocopherols, and the amount of 3-MCPD-E and GE. Increasing the pH of oils leads to a higher content of 3-MCPD-E resulting from deodorisation. As the number of acid groups increases, the amount of 3-MCPD-E increases too. Conversely, with bigger amounts of acid introduced into the oil, no additional quantities of glycidol esters are formed in the course of deodorisation. [ABSTRACT FROM AUTHOR]

Background and Aim: Strangle in the horses is the commonest and the most significant infectious disease. An antibiotic of the first choice, commonly Penicillin, is used for antimicrobial therapy. Due to side effects and resistance against used antibiotics, interest in novel antimicrobial substances from other sources, including herbal medicine as safe agents has been raised. This study evaluated the antibacterial susceptibility profile of Streptococcus equi subsp equi in the confrontation of Trans-cinnamaldehyde, 1, 8 Cineole, and Pulegone on bacterial pathogens isolated from the horse. Materials and Methods: Two hundred clinically isolates were studied by the single disk method to Ampicillin, Ciprofloxacin, Trimethoprim sulfamethoxazole, Gentamicin, Enrofloxacin, Chloramphenicol, Azithromycin, Cefotaxime, Oxytetracycline, Erythromycin, and Penicillin. Paper discs were prepared by impregnation in 10 μL essential oils main compounds (EOMC). The antibacterial activities of Trans-cinnamaldehyde, 1, 8 Cineole, and Pulegone were evaluated by microbroth dilution and disk diffusion methods against isolates of S. equi. Results & Conclusion: All the isolates were resistant to Trimethoprim-sulfamethoxazole and Cefotaxime. The maximum growth inhibition zone was related to Oxytetracycline and Ampicillin. The growth inhibition zone diameter was 30 mm, 20 mm, and 26 mm for Trans-cinnamaldehyde, Pulegone, and 1, 8 Cineole, respectively. The results of the Minimum inhibitory concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) showed that Trans-cinnamaldehyde had the highest antibacterial activity compared to other EOMC against S. equi. This study indicated that Trans-cinnamaldehyde, 1, 8 Cineole, and Pulegone revealed antibacterial properties; therefore, these main constituents of the medicinal plant could be a safe candidate for the new antibacterial products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reaction mechanism of formaldehyde hydroformylation has been established using DFT calculation and experimental study. • The type of solvent determines the conversion pathway of formaldehyde: dissociation mechanism or anionic mechanism. • CH 3 OH, HCOOCH 3 are preferentially produced via the CH 3 O-Rh route in the dissociation mechanism. • CH 3 OH, HOCH 2 CHO are preferentially produced via the HOCH 2 -Rh route in the anionic mechanism. • The calculations predict the strong electron-donating ligand serves to give rise to higher reactivity in the anion mechanism. The aldehyde hydroformylation is of critical importance for synthesis of higher aldehydes and polyhydric alcohols, but the reaction mechanism has not been clearly resolved in the existing literature. In this paper, we have established the dissociation and anion mechanism for formaldehyde hydroformylation using DFT calculation and experimental study. In the dissociation mechanism, HCHO insertion into the Rh-H bond is the rate-controlling step and CH 3 OH, HCOOCH 3 are preferentially produced via the CH 3 O-Rh route. The CO coordination reaction of CH 3 O-Rh(CO) 2 (PPh 3) is not favored energetically leading to facile generation of CH 3 OH relative to HCOOCH 3. In the anion mechanism, the nucleophilic addition of HCHO to the HOCH 2 -Rh species is more energetically favorable and the rate-determining step turns to H 2 oxidation addition. The effective energy barrier of hydrogenolysis for CH 3 OH is higher than that for HOCH 2 CHO, accounting for higher selectivity of HOCH 2 CHO than CH 3 OH observed in the reaction. The calculations also predict the strong electron-donating ligand serves to give rise to higher reactivity in the anion mechanism. [ABSTRACT FROM AUTHOR]

The article reports on turning acetaldehyde as a substrate for organic synthesis. At the Max Planck Institute for Coal Research, Benjamin List and his group managed to use acetaldehyde in the Mannich reaction that allows an opportunity to a range of applications in drug design. List's group combined acetaldehyde with N-Boc-imines in Mannich reaction that formed a single enantiomer. They have tried to improve the yield wherein they successfully optimized the reaction and synthesize a new anti-AIDS drug and other active substances.

In this paper, we discuss the optimization of the operation of a reductive amination (RA) reaction process in a miniplant without an accurate process model using iterative real-time optimization (RTO). The rhodium-catalyzed RA of undecanal with diethylamine produces a tertiary amine from a long-chain aldehyde and is performed in a thermomorphic multiphase system (TMS) to recover and reuse the expensive catalyst efficiently. An iterative RTO method called modifier adaptation with quadratic approximation (MAWQA) is used in combination with guaranteed model adequacy (GMA) to drive the RA process to its optimum iteratively. MAWQA utilizes online measurements to overcome model deficiencies. GMA ensures that the model used in MAWQA satisfies the model adequacy conditions. The optimal operating conditions of the RA process in the miniplant were identified during an experimental run of the plant, thereby validating the applicability and efficiency of MAWQA with GMA. The results illustrate the benefits of process optimization using iterative RTO methods without accurate process models. • Online optimization of a reductive amination process in a mini-plant is performed in the presence of model uncertainty. • An iterative real-time optimization method, modifier adaptation with quadratic approximation is used for optimization. • The issue of undesired input oscillations is avoided by ensuring model adequacy in MAWQA using guaranteed model adequacy. • Experimental results show a smooth convergence to the process optimum. [ABSTRACT FROM AUTHOR]

The ability to catalyse a reaction acting on different substrates, known as "broad-specificity" or "multi-specificity", and to catalyse different reactions at the same active site ("promiscuity") are common features among the enzymes. These properties appear to go against the concept of extreme specificity of the catalytic action of enzymes and have been re-evaluated in terms of evolution and metabolic adaptation. This paper examines the potential usefulness of a differential inhibitory action in the study of the susceptibility to inhibition of multi-specific or promiscuous enzymes acting on different substrates. Aldose reductase is a multi-specific enzyme that catalyses the reduction of both aldoses and hydrophobic cytotoxic aldehydes and is used here as a concrete case to deal with the differential inhibition approach. [ABSTRACT FROM AUTHOR]

• Explored the use of oxide-supported metal catalysts for the AWS reaction. • Use of a reducible oxide enhanced the AWS activity. • Most active materials appeared to catalyze the AWS via a bifunctional mechanism. • Aldol condensation rate correlated with acid site density. There is significant interest in the use of H 2 O as a reactant for production of commodity chemicals and fuels, in particular from water-laden biomass-derived feedstocks. In this paper, we describe results for the aldehyde water shift (AWS), a reaction where aldehydes are partially oxidized by water to produce the corresponding carboxylic acid and H 2 , over a series of CeO 2 -, Al 2 O 3 -, and SiO 2 -supported Cu, Pt, and Au catalysts. The effects of support were further investigated by evaluating the performances of a Cu-Zn-Al water gas shift catalyst and bulk Cu nanoparticles. The supported Cu catalysts were more active than the supported Pt and Au catalysts, and the reducible oxide (CeO 2) supported Cu catalyst had the highest AWS activity. The high activity of the Cu/CeO 2 catalyst is believed to derive from coupling H 2 O dissociation and aldehyde oxidation. The two major side reactions, aldol condensation and aldehyde disproportionation, appeared to be catalyzed by acid and Cu sites, respectively. The results indicate that both the admetal and support play critical roles in catalyzing the AWS reaction and provide guidance for the design of highly active AWS catalysts. [ABSTRACT FROM AUTHOR]

Interstellar complex organic molecules are assumed to be mainly formed on dust–grain surfaces. However, neutral gas-phase reactions in the interstellar medium can play an important role. In this paper, by investigating the reaction between aldehydes and the cyano radical, we show that both formaldehyde (CH2O) and acetaldehyde (CH3CHO) can lead to the formation of formyl cyanide (HCOCN). Owing to accurate quantum-chemical computations followed by rate constant evaluations, we have been able to suggest and validate an effective mechanism for the formation of HCOCN, one of the molecules observed in the ISM. Quite interestingly, the mechanism starting from CH2O is very effective at a low temperature, while that involving CH3CHO becomes more efficient at temperatures above 200 K. [ABSTRACT FROM AUTHOR]

Chemical evolution in molecular clouds in the interstellar medium is well established, with the identification of over 200 molecules and molecular ions. Among the classes of interstellar organic compounds found are the aldehydes. However, laboratory work on the aldehydes has scarcely kept pace with astronomical discoveries as little quantitative solid-phase infrared (IR) data have been published on any of the aldehydes, and the same is true for important properties such as density, refractive indices, and vapour pressures. In this paper, we examine the IR spectra of solid propanal (HC(O)CH2CH3, propionaldehyde), along with several physical properties, for both the amorphous and crystalline forms of the compound. The quantitative measurements we report, such as IR intensities and optical constants, will be useful in laboratory investigations of the formation and evolution of propanal-containing ices, will serve as benchmark data for theoretical investigations, and will inform observational studies. [ABSTRACT FROM AUTHOR]

This paper describes acid-catalysed reactions of 5,7-dimethoxy-1-methylindole and methyl 5,7-dimethoxyindole- 2-carboxylate with a range of aldehydes and ketones. The former indole reacts selectively at C3, whereas the latter reacts preferentially at C4 but also at C3 depending on the reaction conditions. Reactions of indoles with 2,2-dimethoxypropane and triethyl orthoformate are also reported. A range of di- and triindolylmethanes are described, together with an indolo-triptycene of novel structure. [ABSTRACT FROM AUTHOR]

A simple chemometric model is propose to describe the protonation constants of hydrazones and Schiff bases derived from four aldehydes. To test the model, the protonation constants of five hydrazones derived from pyridoxal were determined at T = 298.2 K, p = 0.1 MPa, I = 0.5 mol/L (NaCl). [Display omitted] • Model for prediction of log K b of hydrazones and Schiff bases is proposed. • Regularities from model coefficients are discussed. • Model is tested experimentally and shows good results. Hydrazones and Schiff bases are potent metal chelators applied in various areas such as analytical chemistry and medicine because of their various biological activities, including antimicrobial, antitumor, analgesic, and anti-inflammatory action. The hydrazones and Schiff bases derived from aldehyde forms of the B 6 vitamin are arguably the most biologically active representatives of these classes. Protonation constants associated with pharmacokinetic characteristics are among the most important properties of drug-like molecules as they affect their binding to proteins, membrane transport, excretion, etc. The present paper accumulates data on protonation constants of hydrazones and Schiff bases derived from pyridoxal, pyridoxal 5′-phosphate, 3-hydroxyisonicotinaldehyde, and salicylic aldehyde available in the literature. A novel simple chemometric model is constructed based on these data to describe the protolytic equilibria constants. The model proposed takes into account such molecular descriptors as molecular weight, number of hydrogen bond donors and acceptors, polarizable surface area, and log P. The contribution of ionic strength is also included in the model. The adequacy of the model and the statistical significance of separate parameters are studied using standard mathematical procedures. The protonation constants of five hydrazones derived from pyridoxal and hydrazides of isonicotinic, 2- and 3-furoic, 2- and 3-thiophenecarboxylic acids are determined experimentally in aqueous solution at T = 298.2 K, p = 0.1 MPa and I = 0.50 mol/L (NaCl) and compared with the model predictions. Protonation constants determined can be used further in studies of coordination equilibria of the hydrazones. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Photogenerated electrons and holes were effectively used in one system. • Aromatic alcohols were oxidated into corresponding aldehydes by the photogenerated holes. • Protons were photocatalytically reduced to hydrogen by the photogenerated electrons. • Increased photocatalytic performance and reaction mechanism were investigated. Abstract Effective utilization of photogenerated electrons and holes in a system is always a research hotspot. Photocatalysis has been identified as a promising solution to tackle the current environmental and energy issues. However, photogenerated holes or electrons were wasted in the traditional photocatalytic process. In the paper, a dual-function photocatalytic reaction system was constructed using dispersed Pt x -modified 2D-3D Zn 3 In 2 S 6 hierarchical structures (x = 1–4). In the system, aromatic alcohols were photocatalytically selectively oxidated into aldehydes and protons were reduced to hydrogen by photogenerated holes and electrons, respectively. In the reaction process, one aromatic alcohol is first dehydrogenated into aromatic aldehyde and two H+ via the corresponding carbon-centered radical by consuming of two holes, and then two H+ ions dehydrogenated from OH group and α C H of alcohol are evolved into H 2 by depleting of two electrons. Atomically dispersed Pt x could offer the maximum atom efficiency and significantly promote visible light absorption and separation of photogenerated electron-hole pairs. The cooperative photoredox system exhibits remarkable photocatalytic activity for visible light-driven splitting of aromatic alcohols. Under visible light irradiation for 6 h, The H 2 output over 2.14% Pt/Zn 3 In 2 S 6 reaches up to 950 μmol, which is around 7.5, 5.3 and 3.8 times higher than that over Zn 3 In 2 S 6 , Pt-nanoparticle/Zn 3 In 2 S 6 and MoS 2 /Zn 3 In 2 S 6 , respectively. The apparent quantum efficiency (AQE) of 2.14% Pt/Zn 3 In 2 S 6 at 400 nm is about 4.6%. The utilization rate of photogenerated electrons to holes could be achieved 98.2%. Moreover, Pt/Zn 3 In 2 S 6 hybrid shows high stability even when Zn 3 In 2 S 6 was stored for 12 months. Compared with two half-reactions: the photocatalytic selective organics transformation under O 2 atmosphere and the water splitting with sacrificial reagents, such designed dual-purpose photocatalytic reaction not only could effective use of photogenerated electrons and holes for organics transformation and hydrogen production simultaneously but also shows much higher photocatalytic activity than two half-reactions. At the same time, the work also expands the research field of photocatalysis, such as N 2 fixation and CO 2 reduction by using of the as-produced H+. [ABSTRACT FROM AUTHOR]

Ozone concentrations that are several orders of magnitude greater than typical urban ambient concentrations are necessary for gas-phase ozonation of buildings, either for deodorization or for disinfection of biological agents. However, there is currently no published literature on the interaction of building materials and ozone under such extreme conditions. It would be useful to understand, for example in the case of building re-occupation planning, what types and amounts of reaction products may form and persist in a building after ozonation. In this study, 24 materials were exposed to ozone at concentrations of 1000ppm in the inlet stream of experimental chambers. Fifteen target carbonyls were selected and measured as building ozonation by-products (BOBPs). During the 36h that include the 16h ozonation and 20h persistence phase, the total BOBP mass released from flooring and wall coverings ranged from 1 to 20mgm−2, with most of the carbonyls being of lower molecular weight (C1–C4). In contrast, total BOBP mass released from wood-based products ranged from 20 to 100mgm−2, with a greater fraction of the BOBPs being heavier carbonyls (C5–C9). The total BOBP mass released during an ozonation event is a function of both the total surface area of the material and the BOBP emission rate per unit area of material. Ceiling tile, carpet, office partition, and gypsum wallboard with flat latex paint often have large surface areas in commercial buildings and these same materials exhibited relatively high BOBP releases. The greatest overall BOBP mass releases were observed for three materials that building occupants might have significant contact with: paper, office partition, and medium density fiberboard, e.g., often used in office furniture. These materials also exhibited extended BOBP persistence following ozonation; some BOBPs (e.g., nonanal) persist for months or more at emission rates large enough to result in indoor concentrations that exceed their odor threshold. [Copyright &y& Elsevier]

Polymeric carbon nitride (C 3 N 4 ) is a semiconductor material which is a very promising green photocatalyst with good physico-chemical properties and stability. It is a metal-free carbon based non-toxic material which can be easily obtained from earth-abundant components. The robustness and versatility of C 3 N 4 as a photo-redox catalyst allows its use for selective oxidations by heterogeneous photocatalysis. This paper reviews the state of art in the application of C 3 N 4 as heterogeneous photocatalyst for selective oxidation of alcohols to the corresponding aldehydes. [ABSTRACT FROM AUTHOR]

New 1-[1-(1H-indol-3-yl) alkyl]-1H-indoles, surprisingly, have been obtained from the addition of indole to a variety of aldehydes under neat conditions. CaO, present in excess, was fundamental for carrying out the reaction with paraformaldehyde. Under the same reaction conditions, aromatic and heteroaromatic aldehydes afforded only classical bis (indolyl) aryl indoles. In this paper, the role of CaO, together with the regiochemistry and the mechanism of the reaction, are discussed in detail. The effect of some selected 3,3′- and 1,3′-diindolyl methane derivatives on cell proliferation of the hepatoma cell line FaO was also evaluated. [ABSTRACT FROM AUTHOR]

Termiticidal activity of wood vinegar from Toona sinensis (TS) sawdust has been evaluated against Coptotermes curvignathus. TS wood vinegar was produced at 250-300°C pyrolysis temperature, and a no-choice test was applied for evaluating termiticidal activity with thirty-three active termites. The concentrations of TS wood vinegar in the dried filter paper was prepared to 0% (solvent only), 2%, 4%, 6%, and 8%. The TS wood vinegar showed strong termiticidal activity and that concentrations of wood vinegar significantly influenced mortality of termite. The termite mortality increased when the concentration of wood vinegar increased, at a concentration of 8% all termites dead after 3 days tested. Forty constituents were characteristic on the basis of GC-MS data, and 33 components were identified. The organic compounds in TS wood vinegar were classified into carboxylic acids, phenols, ketones, amides, aldehydes, furans, esters, alcohols, sugar derivative, and ether, and among of this components, acetic acid comprised 57.43%. The contents of organic fraction of TS wood vinegar and largely acetic acid might be responsible for the termiticidal activity. Base on physicochemical properties, TS wood vinegar has a good quality as well. [ABSTRACT FROM AUTHOR]

In this paper, the thermophysical properties of 2-thiophenemethanol and 2-thiophenecarboxaldehyde have been studied: vapour pressures; densities over a wide pressure range; and speeds of sound, refractive indices, surface tension and kinematic viscosities at atmospheric pressure. From these values, the isobaric expansibility, the isothermal and isentropic compressibilities, the internal pressure, the molar refraction and the dynamic viscosity are obtained. Both experimental and calculated results were used to evaluate the different molecular organization in the two fluids. The results show an H-bond network and a higher intermolecular free volume for the alcohol derivative. Moreover, we have obtained the parameters of the PC-SAFT equation of state for the studied compounds as well as the influence parameter in the Density Gradient Theory. The obtained average mean relative deviations for the correlated properties were: MRD ( p v ) = 1.78%, MRD ( ρ ) = 0.25%, MRD ( u ) = 15%, and MRD ( σ ) = 0.12%. [ABSTRACT FROM AUTHOR]

Multiple functionalization of nanoparticles has attracted great interest in drug delivery. In this paper, polymeric amphiphiles of polyethylenimine (PEI) conjugated with methoxy poly(ethylene glycol) aldehyde (mPEG-CHO), poly(ε caprolactone) aldehyde (PCL-CHO) and pyrene-1-carboxaldehyde (Py-CHO) were synthesized via Schiff’s reaction. The conjugates self-assembled into nanoparticles with pH-sensitivity to load anticancer drug doxorubicin (DOX), further coated with hyaluronic acid (HA) for tumor targeting. The mean size of nanoparticles was about 100 nm and the stability of the nanoparticles was well in aqueous solution. The nanoparticles coated with HA showed faster disassembly in acidic solution, resulting in faster drug release in the medium with pH 5.0 compared to uncoated nanoparticles. Moreover, the nanoparticles exhibited an endosomal escape function to accelerate the release of DOX in cancer cells, which led to low IC 50 s to kill breast cancer cells (4T1) and liver cancer cells (HepG2) in vitro. [ABSTRACT FROM AUTHOR]

Oxidation is one of the most important industrial reactions as it yields useful products. Literature survey indicates the use of several organic oxidants for the oxidation of alcohols to the corresponding carbonyl compounds but inorganic oxidants have rarely been used. Further, the kinetic and thermodynamic aspects of oxidation of perfumery alcohols have not been investigated. In this paper, we report the kinetic studies of oxidation of acyclic primary perfumery alcohols, Nerol, Citronellol and Geraniol, to aldehydes using K2S2O8 and KIO4 in acidic medium. The oxidation was carried out under first order kinetic conditions with respect to the inorganic oxidants. The progress of reaction was monitored by iodometric estimation of the unreacted oxidants at regular time interval during the course of the reaction. The reaction was found to be independent of ionic strength (μ).The thermodynamic activation parameters have been determined from the variation of oxidation rate with temperature. Suitable reactionmechanism have been suggested for the oxidation of perfumery alcohols. [ABSTRACT FROM AUTHOR]

An efficient synthesis of milnacipran hydrochloride has been accomplished. The important application of this paper is the reductive amination of aldehyde to primary amine with water soluble reagents. This method provides a high yield of primary amine as the major product, reduces the number of steps, and discourages by-products. [ABSTRACT FROM AUTHOR]

Lime mud, the industrial waste from pulp and paper mills, was used as a raw material for preparing calcium oxide (CaO)-based catalysts. Lime mud was heated at 1000 °C to transform it into active CaO and then modified by adding 5 wt% Fe or Ni (as nitrates) using the wet impregnation method and calcining to form the Fe/CaO and Ni/CaO catalysts. The fast pyrolysis of Jatropha residues to bio-oil with no catalyst and with the derived CaO, Fe/CaO and Ni/CaO catalysts was studied using an analytical pyrolysis-GC/MS at 500 °C at a biomass: catalyst ratio of 1:1 and 1:5. A Jatropha residue: catalyst ratio of 1:5 was more optimal for enhancing aliphatic hydrocarbon production and decreasing the amount of oxygenated and N-containing compounds. The presence of the CaO catalyst completely eliminated the undesirable acids and sugars in the bio-oil, significantly decreased N-containing compounds and considerably promoted the formation of aliphatic hydrocarbons up to 37.3%. The Fe/CaO and Ni/CaO catalysts further increased the selectivity for aliphatic hydrocarbons, and reduced aldehyde formation compared to with CaO, with Ni/CaO being the best catalyst for hydrocarbon selectivity (47.5%). Overall, these CaO-based catalysts derived from industrial lime mud waste can be used for catalytic fast pyrolysis applications. [ABSTRACT FROM AUTHOR]

Peroxisome proliferator-activated receptor γ (PPARγ) is a well-known target for thiazolidinedione antidiabetic drugs. In this paper, we present the synthesis and biological evaluation of a series of dihydropyrano[2,3-c]pyrazole derivatives as a novel family of PPARγ partial agonists. Two analogues were found to display high affinity for PPARγ with potencies in the micro molar range. Both of these hits were selective against PPARγ, since no activity was measured when tested against PPARα, PPARδ and RXRα. In addition, a novel modelling approach based on multiple individual flexible alignments was developed for the identification of ligand binding interactions in PPARγ. In combination with cell-based transactivation experiments, the flexible alignment model provides an excellent analytical tool to evaluate and visualize the effect of ligand chemical structure with respect to receptor binding mode and biological activity. [ABSTRACT FROM AUTHOR]

Immobilized and stabilized lipases are important biocatalytic tools. In this paper, different tailor-made bifunctional supports were prepared for the immobilization of a new metagenomic lipase (LipC12). The new supports contained hydrophobic groups (different alkyl groups) to promote interfacial adsorption of the lipase and aldehyde groups to react covalently with the amino groups of side chains of the adsorbed lipase. The best catalyst was 3.5-fold more active and 5000-fold more stable than the soluble enzyme. It was successfully used in the regioselective deacetylation of peracetylated D-glucal. The PEGylated immobilized lipase showed high regioselectivity, producing high yields of the C-3 monodeacetylated product at pH 5.0 and 4 ˚C. [ABSTRACT FROM AUTHOR]

The current paper provides an overview of recent and past research activities in the field of microreactors for selective oxidation reactions. The majority of the research efforts are currently focussing on the direct synthesis of hydrogen peroxide, aldehydes and carboxylic acids and the preferential (selective) removal of carbon monoxide out of hydrogen rich reaction mixtures. Catalyst development, process optimisation and reactor design are under investigation. Numerous examples demonstrate the advantages of microstructured reactors for the reaction systems envisaged through the improved catalyst utilization, heat management and potential operation under hazardous conditions, especially in the explosive regime. [ABSTRACT FROM AUTHOR]

Abstract: Volatile aldehydes are produced during degradation of paper-based materials. This may result in their accumulation in archival and library repositories. However, no systematic study has been performed so far. In the frame of this study, passive sampling was carried out at ten locations in four libraries and archives. Despite the very variable sampling locations, no major differences were found, although air-filtered repositories were found to have lower concentrations while a non-ventilated newspaper repository exhibited the highest concentrations of volatile aldehydes (formaldehyde, acetaldehyde, furfural and hexanal). Five employees in one institution were also provided with personal passive samplers to investigate employees’ exposure to volatile aldehydes. All values were lower than the presently valid exposure limits. The concentration of volatile aldehydes, acetic acid, and volatile organic compounds (VOCs) in general was also compared with that of outdoor-generated pollutants. It was evident that inside the repository and particularly inside archival boxes, the concentration of VOCs and acetic acid was much higher than the concentration of outdoor-generated pollutants, which are otherwise more routinely studied in connection with heritage materials. This indicates that further work on the pro-degradative effect of VOCs on heritage materials is necessary and that monitoring of VOCs in heritage institutions should become more widespread. [Copyright &y& Elsevier]

The paper is aimed to demonstrate how the activity and selectivity of a Pt/SiO2 catalyst can be tailored by introduction of tin either to hydrogenate the aldehyde group in α,β-unsaturated aldehydes (UA) or oxidize carbon monoxide at room temperature. In this paper general aspects of catalyst design based on the use of tin tetraalkyls are described in detail. Results summarized in this work show that upon using new approaches for anchoring tin into platinum high Snanch/Pts can be achieved. The experimental evidences indicate also that the hydrogenation of the aldehyde group in α,β-unsaturated aldehydes and oxidation of CO requires in situ formed “Sn4+–Pt ensemble” sites to activate either the carbonyl group or the CO molecule. [Copyright &y& Elsevier]

Although amorphous Pt nanocatalysts have excellent activity for chemoselective hydrogenation of cinnamaldehyde, the selectivity and stability need to be further enhanced. In this paper, adenine (A) was used as a structure reinforcer to enhance the chemical stability of Fe- L -aspartic (Fe-Asp) coordination compound. The modified Fe-Asp-A support was employed to load Pt nanoparticles, and the resulting amorphous Pt/Fe-Asp-A nanocatalyst exhibited excellent activity, selectivity and stability. Under 50 °C, the conversion of cinnamaldehyde to cinnamyl alcohol was 93.1 % with selectivity of 91.2 %. Moreover, the catalytic performance of amorphous Pt/Fe-Asp-A nanocatalyst kept unchanged after 10 cycles. The amorphous Pt/Fe-Asp-A nanocatalyst could open a new door for high-efficiency selective catalytic hydrogenation of α, β-unsaturated aldehydes. [Display omitted] • Amorphous Pt/Fe-Asp-A catalysts exhibited good catalytic performance. • The CMA conversion and CMO selectivity were 93.1 % and 91.2 % under 50 °C. • Pt/Fe-Asp-A catalyst showed excellent catalytic stability. [ABSTRACT FROM AUTHOR]

The degradation of ammonia is a key rate-limiting step during the supercritical water oxidation of nitrogen-containing organics. This paper studied the co-oxidation behavior between different ammonia-alcohol environments, including the influence of reaction parameters and the co-oxidation mechanism. The results showed that increasing temperature, oxidation coefficient, residence time, and alcohol concentration significantly promoted the degradation of NH 3 –N and TOC, while rising the ammonia concentration enhanced the NH 3 –N destruction but inhibited the TOC degradation. Alcohols were oxidized first in the co-oxidation system to produce more OH* and HO 2 * radicals. Ethanol generated the highest concentration of HO 2 * in the shortest time, leading to more significant ammonia removal than isopropanol and methanol; however, the produced intermediate products like aldehydes and ketones reacted with residual ammonia to generate a small amount of organics at lower temperatures, inhibiting the degradation of alcohols slightly, and combined catalyst or nitrate in the batch reactor or used continuous supercritical water oxidation or supercritical hydrothermal combustion system without controlling the exotherm of fuels could improve this. [Display omitted] • Co-oxidation behavior between monohydric alcohols-ammonia system is studied. • The effect of operation parameters on degrading alcohols and ammonia is discussed. • The enhancement mechanism of alcohols in the treatment of ammonia is analyzed. • Transformation pathways of nitrogen in the alcohols-ammonia system are clarified. • Suggestions about improving the co-oxidation processes are put forward. [ABSTRACT FROM AUTHOR]

In this paper, a novel methodology for the synthesis of ketones via microwave irradiation promoted direct alkylation of aldehydes by activation of the inert C(sp³)-H bond has been developed. Notably, the reactions were accomplished under metal-free conditions and used commercially available aldehydes and cycloalkanes as substrates without prefunctionalization. By using this novel method, an alternative synthetic approach toward the key intermediates for the preparation of the pharmaceutically valuable oxaspiroketone derivatives was successfully established. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the aromatic profiles of volatile compounds in the pulp of 'Abbas' fig variety by SPME headspace methods for (CAR/PDMS, PDMS, CAR/PDMS/DVB) procedure for GC/MS (Gas Chromatography-Mass Spectrometry) technique. The volatile compounds are known to contain different biochemical substances that can be classified as aldehydes, alcohols, esters, terpenic compounds and other compounds. According to the results of current study, pulp of the 'Abbas' fig variety was found to include twenty-five different volatile compounds. The dominant volatile compounds in dried figs are aldehydes and esters. Total esters were found to be higher than other classes of compounds. Among other compounds, detected in volatiles of the pulps were 1-hydroxy-2-propanone (CAS), isocaproic acid, benzaldehyde, 2-ethyl-Hexanol, and pentyl-alpha-furoate. [ABSTRACT FROM AUTHOR]

This paper describes the first rhodium-catalyzed hydroformylation of cyclopentadiene (Cpd) using a homogeneous catalyst system consisting of [Rh(OAc) 2 ] 2 and the chelate ligand BISBI. At a reaction temperature of 100 °C and a syngas pressure of 30 bar the cyclopentane carbaldehyde is formed in 68% yield while 20% of the respective dialdehyde species are obtained within 3 hours. An important side reaction in Cpd hydroformylation reaction can be the dimerization of Cpd to its dimer dicyclopentadiene (Dcpd). This unwanted side reaction could be overcome by the use of tertiary alkyl amines as additives. Furthermore, the possibility to steer the reaction via the influence of the bite angle of diphosphine ligands was found. [ABSTRACT FROM AUTHOR]

Transfer hydrogenation has become a versatile and practical method for reduction in organic synthesis. The development of aqueous transfer hydrogenation reactions is not only fundamentally interesting in terms of understanding enzymatic catalysis, but also offers economic and environmental benefits, as water is cheap and nontoxic. In this review paper, an account of the work on transfer hydrogenation in aqueous media done by the Xiao group is given. Aqueous transfer hydrogenation of ketones, aldehydes and heterocycles as well as reductive amination reactions, including extension into biomass-derived platform molecules, has been successfully developed employing the classical Noyori-type catalysts or the newly invented iridacycles, with most of the reactions taking place “on water”. Water is shown to be an enabling medium for transfer hydrogenation reactions of various features. Not only can it accelerate a reduction, it also provides a simple tool, the solution pH, to control a reaction. [ABSTRACT FROM AUTHOR]

In this paper, N-Boc and N-Cbz protected α-branched amines are synthesized directly from commercially available aromatic/heteroaromatic compounds, aldehydes, and tert-butyl or benzyl carbamate bearing a variety of substituents. Bismuth(III) triflate is found to be a highly effective catalyst for this one-pot, three-component coupling reaction. In addition, the use of mild reaction conditions, low catalytic loading, easy removal of the N-protective group, and one-step synthesis under "open-flask" are advantages of the present procedure. [ABSTRACT FROM AUTHOR]

This paper deals with photocatalysis (TiO 2 + UV), nonthermal plasma (NTP) and their combinations. These processes have been widely studied for isovaleraldehyde (Isoval) treatment. Isoval removal, selectivity of CO 2 and CO, and ozone formation are investigated in order to evaluate the performance of the combined process. The results show that the performance of the process has enhanced and a synergetic effect is observed. On the other hand, this work aims at investigating kinetic modeling of combined process with taking into account the mass transfer step. The model is based on mass balances in three types of region: bulk region, discharge zone and solid phase which contains the photocatalyst. The oxidation in discharge and solid phases is described in two stages. Firstly, the removal of Isoval gives an equivalent intermediate (EI). Secondly, EI is oxidized into carbon dioxide (CO 2 ) and carbon monoxide (CO). This simplified approach of removal allows for an agreement between modeling and empirical data in terms of degradation and mineralization. It also allows for the simulation of NTP and photocatalytic kinetics without knowing the plausible pathway. Moreover, the synergetic effect can be represented correctly by increasing mass transfer constant. [ABSTRACT FROM AUTHOR]