Aldehyde Molecules Research Articles

A Urease-Catalyzed Three-Component Reaction for the Efficient and Sustainable Synthesis of Highly Substituted 4H-Pyrans in Water as the Solvent

AbstractAn efficient urease-catalyzed approach for the synthesis of highly substituted 6-amino-4H-pyran-3-carbonitriles based on the formation of three bonds in one step is developed. This unprecedented three-component reaction between one molecule of an aromatic aldehyde and two molecules of an aroylacetonitrile proceeds by employing commercially available urease from jack bean (Canavalia ensiformis) as the catalyst in water at 65 °C to deliver the desired 4H-pyrans in yields of up to 92%. The transformation is proposed to occur via a domino Knoevenagel condensation/1,4-addition/O-cyclization/tautomerization sequence, providing a practical and sustainable approach to 6-amino-4H-pyran-3-carbonitriles from commercially available substrates. Full and unambiguous structural elucidation of all the products is achieved by means of NMR spectroscopy and X-ray crystal structure analysis.

Effects of low-temperature plasma, microwave and 60Co γ-irradiation treatments on the flavor characteristics of lychee whole fruit powder

Powdering whole lychee fruit is one of the most effective methods for improving the comprehensive utilization rate of lychees. In this study, lychee whole fruit powder (LWFP) was prepared and treated with low-temperature plasma, microwave, and 60Co γ-irradiation treatments to enhance its quality. Volatile organic compounds (VOCs) were analyzed using Headspace Solid Phase Micro-extraction Gas Chromatography-mass Spectrometry (HS-SPME-GC-MS), Headspace Gas Chromatography Ion Mobility Spectrometry (HS-GC-IMS), and electronic nose (E-nose) techniques. Electronic tongue (E-tongue) analysis revealed that both sweetness and bitterness were significant taste indicators of LWFP. GC-MS analysis revealed that the predominant volatile compounds in LWFP were terpenoids and alcohols, specifically nerol, geraniol, ɑ-pinene, hexylbenzene, ɑ-caryophyllene, caryophyllene oxide, and isoamylenol. GC-IMS identified small-molecule aldehydes such as 2-methyl propanal, hexanal, propanal, and 2-methylbutanal as significant contributors to the aroma profile. Moreover, key aromatic contributors include dimethyl sulfide, 1-penten-3-one, and acetic acid. Notably, microwave treatment exerted the most significant effect on the aroma profile of lychee. In contrast, low-temperature plasma and irradiation treatments exhibited similar and consistent changes. Specifically, microwave treatment primarily increased the concentration of larger terpenoid molecules such as nerol, 1-phenylhexane, and caryophyllene oxide, whereas low-temperature plasma and irradiation had a greater impact on smaller aldehyde molecules such as hexanal and 2-methylbutanal. All treatments enriched the sweet fruity, brilliant woody, and cabbage scents of LWFP.

Cascade approach to synthesize BIMs and analogues in different nucleophilic conditions

We report here a cascade synthetic approach to prepare 3,3′-bis(indolyl)methanes (BIMs) and analogues from single reactant 1H-indole-3-carbaldehydes under the reductive condition using NaBH4. Uniformly, in another strategy, 1H-indole-3-carbaldehydes produced BIMs as a cascade product under Grignard reaction conditions. This is the first application of organometallic and reductive nucleophilic condition, where indole-3-carbaldehydes underwent NaBH4 reduction/ methyl Grignard addition to form 1°/2° alcohol followed by elimination and subsequent addition of another molecule of indole aldehyde provided symmetric BIMs as unambiguous cascade products (22 analogues) in good to excellent yields.

Rotating Disk Electrode Studies of Benzaldehyde Oxidation on Group Ib Metals

Water electrolysis is a green means of producing hydrogen gas to be used as a fuel or reactant in key industrial processes such as ammonia production. The conventional system of oxygen evolution (OER) and hydrogen evolution (HER) suffers from slow kinetics at the anode and a high cell voltage limited by thermodynamics. One solution is to replace OER with another reaction such as an organic oxidation reaction that has a lower equilibrium potential and produces a valuable organic byproduct at the anode. Recent work has demonstrated that biomass-derived aldehydes such as furfural and 5-hydroxymethylfurfural can be selectively oxidized to their corresponding carboxylates and H2 on Cu-based anodes at low potentials (~0.1 VRHE) in alkaline media. In alkaline media, a hydroxide ion adds to the carbonyl carbon of an aldehyde molecule forming a gem diolate in solution phase. It is argued that dehydrogenation becomes more facile due to the weaker C-H bond of the gem diolate compared to the aldehyde form of the molecule. This may enable oxidation without the need for coadsorbed-OH. Additionally, aldehyde oxidation is only active on Au, Ag, and Cu electrodes at higher pHs.The aim of this work is to identify the conditions under which low potential oxidation of aldehydes and high anodic Faradaic efficiency to H2 occurs, namely, electrode material and applied potential. To avoid polymerization side reactions of furans in alkaline media, we studied benzaldehyde as a model compound which has also been shown to exhibit low potential oxidation and anodic H2. The activity (rate of aldehyde consumption) and selectivity (to anodic H2 versus H2O) were compared for the group Ib metals (Au, Ag, Cu), each of which demonstrates a relatively early onset potential (<0.4 VRHE) and generates anodic H2 at certain potentials. Rotating disk electrode studies with Koutecky-Levich analysis were conducted to separate mass transfer effects from kinetic current to compare the intrinsic activity of each electrode. Additionally, the average number electrons transferred per aldehyde molecule consumed was estimated from Koutecky-Levich analysis; the one-electron pathway combines the aldehyde hydrogens to H2 while the two-electron pathway requires an additional electron per aldehyde molecule to oxidize the hydrogen from the surface to form H2O. Rotating ring disk electrode studies were used to further validate the anodic H2 generation as a Pt ring was still able to oxidize H2 despite the presence of benzaldehyde. This was used as an additional means of estimating the selectivity to H2 as a function of potential.CVs for benzaldehyde oxidation on each metal are shown in Figure a. Peak current followed the order of Au > Ag >> Cu. Au reached a mass transfer limiting current, and Ag also showed an RPM dependence but did not reach full mass transfer limitations. Cu was the least active and did not show any mass transfer dependence. On the other hand, Cu has the earliest onset potential followed by Ag then Au. The average number of electrons transferred per aldehyde molecule according to RRDE measurements is shown in Figure b, where one electron represents H2 and two electrons represents H-oxidation to H2O. Cu had 100% selectivity to H2 over its entire potential window of activity (up to 0.45 VRHE). Au and Ag have high selectivity to H2 at low potentials but decreases to near zero H2 production in the range of 0.6-0.8 VRHE; the decrease in selectivity to H2 on Ag occurs slightly earlier than Au (~0.1 V). H2 selectivity is related to the inability of each metal to oxidize H to H2O at low potentials. Figure 1

Cluster-Level Heterostructure of PMo12/Cu for Efficient and Selective Electrocatalytic Hydrogenation of High-Concentration 5-Hydroxymethylfurfural.

Electrochemical hydrogenation of aldehyde molecules, exemplified by 5-hydroxymethylfurfural (HMF), offers a sustainable approach for synthesizing higher value-added alcohols. However, severe coupling side reactions impede its practical implementation at high concentrations. In this work, a cluster-level heterostructure of a PMo12/Cu catalyst is synthesized by loading Keggin-type phosphomolybdic acid (H3PMo12O40, PMo12) onto Cu nanowires. The catalyst exhibits high selectivity in electrocatalytic hydrogenation (ECH) of HMF to 2,5-bishydroxymethylfuran (BHMF) under an unprecedentedly high substrate concentration of 1.0 M. Under -0.3 V (vs RHE) with 1.0 M HMF, PMo12/Cu shows a Faradaic efficiency as high as 98% with an excellent productivity of 4.35 mmol cm-2 h-1 toward BHMF, much higher than those on the pristine Cu nanowires. Mechanism studies and density functional theory calculations demonstrate that the heterostructural interface of PMo12/Cu serves as an active reaction center for the ECH. The unique electronic properties and geometric structure promote the dissociative reduction of water molecules to generate H* and reduce HMF with a decreased reaction energy barrier, which is responsible for exceptional reactivity and selectivity.

Design, structural characterization, DFT, molecular docking, and chemotherapeutic activity of novel platinum(II) and palladium(II) complexes derived from Metformin-based Schiff base

Two novel bidentate Schiff bases ligands derived from Metformin with aldehydic molecules, including o-Ethoxy benzaldehyde (L1) and thiophene-2-carbaldehyde (L2) and Pt(II) and Pd(II) complexes were prepared. Numerous techniques were used to study the ligands and their metal complexes, including mass spectroscopy, IR, UV–Vis, molar conductivity, magnetic moment measurement, 1HNMR, PXRD, and 13CNMR. The preceding two Schiff bases were coordinated to Pd (II) and Pt (II) in the molar ratio of (1:1) (M:L) with the molecular structure [MLCl2]. The chemical quantum characteristics were calculated, and Schiff bases' optimized geometric structures and their complexes were revised theoretically. The MCF-7 breast cancer model was used to test the anticancer effects of metformin Schiff bases and their complexes in vitro. Additionally, using the EGFR tyrosine kinase of the selected proteins, a molecular docking study was carried out to learn more about the docking active site interactions. Ultimately, the conventional DPPH method was used to assess the antioxidant activity of the free ligands and their metal chelates. Pt (II) complexes demonstrated greater free radical scavenging activity than ascorbic acid. Furthermore, Pt (II) complexes showed more effective interactions with the selected mTOR protein, which is assumed to help the COVID-19 virus proliferate. Thus, Pt (II) has a bright future in the realm of chemotherapy.

Genome-wide identification and analysis of the cotton ALDH gene family

BackgroundAldehyde dehydrogenases (ALDHs) are a family of enzymes that catalyze the oxidation of aldehyde molecules into the corresponding carboxylic acid, regulate the balance of aldehydes and protect plants from the poisoning caused by excessive accumulation of aldehydes; however, this gene family has rarely been studied in cotton.ResultsIn the present study, genome-wide identification was performed, and a total of 114 ALDH family members were found in three cotton species, Gossypium hirsutum, Gossypium arboreum and Gossypium raimondii. The ALDH genes were divided into six subgroups by evolutionary analysis. ALDH genes in the same subgroup showed similar gene structures and conserved motifs, but some genes showed significant differences, which may result in functional differences. Chromosomal location analysis and selective pressure analysis revealed that the ALDH gene family had experienced many fragment duplication events. Cis-acting element analysis revealed that this gene family may be involved in the response to various biotic and abiotic stresses. The RT‒qPCR results showed that the expression levels of some members of this gene family were significantly increased under salt stress conditions. Gohir.A11G040800 and Gohir.D06G046200 were subjected to virus-induced gene silencing (VIGS) experiments, and the sensitivity of the silenced plants to salt stress was significantly greater than that of the negative control plants, suggesting that Gohir.A11G040800 and Gohir.D06G046200 may be involved in the response of cotton to salt stress.ConclusionsIn total, 114 ALDH genes were identified in three Gossypium species by a series of bioinformatics analysis. Gene silencing of the ALDH genes of G. hirsutum revealed that ALDH plays an important role in the response of cotton to salt stress.

Gas-phase ion mobility of protonated aldehydes in helium measured using a selected ion flow-drift tube.

In soft chemical ionization mass spectrometry, analyte ions are produced via ion-molecule reactions in the reactor. When an electric field E is imposed, the ion drift velocity vd determines the reaction time and the effective ion temperature. Agreement between experimental ion mobilities and theoretical predictions confirms the accuracy of the ion residence time measurement procedure. A selected ion flow-drift tube (SIFDT), an instrument with a chemical ionization source, was used to produce protonated aldehydes and selectively inject them into the resistive glass drift tube filled with He. Arrival-time distributions of ions were obtained using the Hadamard modulation. Reduced ion mobilities were then obtained at a pressure of 2hPa in the E/N range of 5-15 Td. Theoretical ion mobility values were calculated using two methods: hard-sphere approximation and trajectory modelling. The measured mobilities of three saturated and three unsaturated protonated aldehydes do not show substantial variation across the studied E/N range. Effective temperatures calculated using the Wannier formula from measured gas temperatures ranged from 300 to 315 K. Experimentally obtained values of the near-zero- E/N-reduced ion mobilities agree with both methods of calculations typically within ±3% standard deviation (maximum ±5%). The experimental SIFDT values of reduced mobilities in He of protonated aldehyde molecules generated from a chemical ionization source are in close agreement with two different theoretical methods based on the density functional theory calculations of ion geometries and partial atomic charges. Besides its fundamental importance, the ion mobility results validate the correct operation of the drift tube reactor and the ion residence time measurement procedure. Diffusion losses can also be determined from these results.

Selective nitride passivation using vapor-dosed aldehyde inhibitors for area-selective atomic layer deposition

We present a methodology for achieving selective deposition of Ru films through surface modification via vapor-phase functionalization of aldehyde inhibitor molecules. We conduct a comparative evaluation of the blocking capability using vapor-dosing of two different types of aldehyde molecules: undecylaldehyde and benzaldehyde as aliphatic and aromatic ring inhibitors, respectively, on W, TiN, SiN, and SiO2 substrates. By adjusting the vapor-process conditions of both aldehydes, we confirm chemo-selective adsorption on nitride surfaces, resulting in significant growth retardation during subsequent Ru atomic layer deposition. Under optimized conditions for achieving nitride versus oxide selectivity, we successfully demonstrated area-selective atomic layer deposition (AS-ALD) of Ru films on patterned-TiN/SiO2 substrates.

Area-selective atomic layer deposition of Ru thin films by chemo-selective inhibition of alkyl aldehyde molecules on nitride surfaces

Area-selective atomic layer deposition (AS-ALD) on pre-defined areas is of crucial importance nowadays in significantly reducing complexities associated with current top-down fabrication processes. In this work, we report the effects of surface modification using various alkyl aldehyde inhibitors with different chain lengths—hexanal, decanal, and undecanal—on nitride surfaces such as TiN and SiN to achieve AS-ALD. On the basis of density functional theory calculations and experimental analysis, including water contact angle and X-ray photoelectron spectroscopy, it is evident that aldehydes would chemo-selectively react with the –NH2 functional groups present on the nitride surfaces. Then, we further investigate their blocking ability against subsequent Ru ALD, a promising next-generation electrode material. It is worth noting that the Ru deposition thickness decreased by 4–10 nm with the presence of undecanal adsorbed on SiN and TiN substrates. Finally, we successfully demonstrate AS-ALD of Ru thin films over 8 nm on a patterned TiN/SiO2 substrate. These results hold potential for applications in bottom-up nanofabrication techniques for next-generation nanoelectronic applications.

Quest for a Desolvated Structure Unveils Breathing Phenomena in a MOF Leading to Greener Catalysis in a Solventless Setup: Insights from Combined Experimental and Computational Studies.

The crystal structure of the metal-organic framework (MOF), {Mn2(1,4-bdc)2(DMF)2}n (1) (1,4-bdcH2, 1,4-benzenedicarboxylic acid; DMF, N,N-dimethylformamide), is known for a long time; however, its desolvated structure, {Mn2(1,4-bdc)2}n (1'), is not yet known. The first-principles-based computational simulation was used to unveil the structure of 1' that shows the expansion in the framework, leading to pore opening after the removal of coordinated DMF molecules. We have used 1' that contains open metal sites (OMSs) in the structure in cyanosilylation and CO2 cycloaddition reactions and recorded complete conversions in a solventless setup. The pore opening in 1' allows the facile diffusion of small aldehyde molecules into the channels, leading to complete conversion. The reactions with larger aldehydes, 2-naphthaldehyde and 9-anthracenecarboxaldehyde, also show 99.9% conversions, which are the highest reported until date in solventless conditions. The in silico simulations illustrate that larger aldehydes interact with Mn(II) OMSs on the surfaces, enabling a closer interaction and facilitating complete conversions. The catalyst shows high recyclability, exhibiting 99.9% conversions in the successive reaction cycles with negligible change in the structure. Our investigations illustrate that the catalyst 1' is economical, efficient, and robust and allows reactions in a solventless greener setup, and therefore the catalysis with 1' can be regarded as "green catalysis".

Comprehensive analysis of the aldehyde dehydrogenase gene family in Phaseolus vulgaris L. and their response to saline-alkali stress.

Aldehyde dehydrogenase (ALDH) scavenges toxic aldehyde molecules by catalyzing the oxidation of aldehydes to carboxylic acids. Although ALDH gene family members in various plants have been extensively studied and were found to regulate plant response to abiotic stress, reports on ALDH genes in the common bean (Phaseolus vulgaris L.) are limited. In this study, we aimed to investigate the effects of neutral (NS) and basic alkaline (AS) stresses on growth, physiological and biochemical indices, and ALDH activity, ALDH gene expression of common bean. In addition, We used bioinformatics techniques to analyze the physical and chemical properties, phylogenetic relationships, gene replication, collinearity, cis-acting elements, gene structure, motifs, and protein structural characteristics of PvALDH family members. We found that both NS and AS stresses weakened the photosynthetic performance of the leaves, induced oxidative stress, inhibited common bean growth, and enhanced the antioxidative system to scavenge reactive oxygen species. Furthermore, we our findings revealed that ALDH in the common bean actively responds to NS or AS stress by inducing the expression of PvALDH genes. In addition, using the established classification criteria and phylogenetic analysis, 27 PvALDHs were identified in the common bean genome, belonging to 10 ALDH families. The primary expansion mode of PvALDH genes was segmental duplication. Cis-acting elemental analysis showed that PvALDHs were associated with abiotic stress and phytohormonal responses. Gene expression analysis revealed that the PvALDH gene expression was tissue-specific. For instance, PvALDH3F1 and PvALDH3H1 were highly expressed in flower buds and flowers, respectively, whereas PvALDH3H2 and PvALDH2B4 were highly expressed in green mature pods and young pods, respectively. PvALDH22A1 and PvALDH11A2 were highly expressed in leaves and young trifoliates, respectively; PvALDH18B2 and PvALDH18B3 were highly expressed in stems and nodules, respectively; and PvALDH2C2 and PvALDH2C3 were highly expressed in the roots. PvALDHs expression in the roots responded positively to NS-AS stress, and PvALDH2C3, PvALDH5F1, and PvALDH10A1 were significantly (P < 0.05) upregulated in the roots. These results indicate that AS stress causes higher levels of oxidative damage than NS stress, resulting in weaker photosynthetic performance and more significant inhibition of common bean growth. The influence of PvALDHs potentially modulates abiotic stress response, particularly in the context of saline-alkali stress. These findings establish a basis for future research into the potential roles of ALDHs in the common bean.

Investigations Using Molecular Docking and Simulation on the Antidiabetic Activity of Resveratrol Aldehyde Molecule.

Investigations Using Molecular Docking and Simulation on the Antidiabetic Activity of Resveratrol Aldehyde Molecule.

A sequential reaction of picolinamide with benzaldehydes promoted by Pd(TFA)2: rapid access to 4,5-disubstituted 2-(pyridin-2-yl)oxazoles in n-octane.

We developed a synthetic method for obtaining 4,5-disubstituted 2-(pyridin-2-yl)oxazoles from picolinamide and aldehydes by employing Pd(TFA)2 as the catalyst in n-octane. This cascade reaction involves the condensation of picolinamide and two aldehyde molecules promoted by trifluoroacetic acid (TFA) generated in situ from Pd(TFA)2. This one-pot protocol provides rapid access to synthetically valuable triaryloxazoles from readily available starting materials under mild conditions. An 18O labeling study revealed that this tandem reaction proceeded via a different reaction mechanism compared to the Robinson-Gabriel oxazole synthesis.

A LA-BTC MOF as a sensor element of an electronic nose for selective adsorption of biomarkers of diseases: Molecular dynamics simulations of adsorption

The advanced non-invasive diagnostic method is an analysis of exhaled volatile organic compounds (VOCs), which are regarded as biomarkers of various diseases. A gravimetric-type electronic nose (e-nose) has shown great promise in exhaled VOC-pattern identification, and its efficiency is determined by the adsorption capacity of the sensing materials towards a specific VOC. The present study employed molecular dynamics (MD) calculations with the OPLS all-atom force field to investigate the adsorption of an isolated molecule of volatile fatty acids, acetone, ethanol, methanol, acetic aldehyde, neopentane, and ethane in a unit cell of the lanthanum-based metal-organic framework (La-BTC MOF), which was proposed as a potential sensing material for the gravimetric-type e-nose. The adsorption potential determined as a change in the potential energy, ΔEp, of the total simulation system upon the penetration of a single molecule into a unit pore of La-BTC MOF was calculated for all the targeted VOCs and water to be 1.56–10.78 kJ·mol−1, following the order: ethane < neopentane < acetic aldehyde < ethanol < methanol < water < acetone < butanoic acid < caproic acid. Therefore, the biomarkers with ΔEp > ΔEp(water) ∼ 7.3 kJ/mol can be captured from the exhaled breath. According to the MD calculations, an oxygen-containing biomarker molecule in the adsorbed state was oriented by its oxygen atom towards the La3+ cation, so that the O---La3+ distance of 0.28–0.32 nm was the shortest among those for other constituent atoms. Thus, the strong electrostatic interactions between the oxygen atoms of the adsorbate molecules and the La3+ cation of the adsorbent were most responsible for the capture of the oxygen-containing biomarkers by the La-BTC MOF. The competing adsorption effect between water and oxygen-containing biomarker molecules was examined in dependence on the water content and the way the water molecules were introduced into the simulation system.

Mass spectrometric monitoring of ligand-bridged hot electron transfer and anaerobic oxidization on auto renewable droplet-based plasmonic nanoreactors under visible light illumination

The light induced hot-electron on plasmonic nanostructures has been recognized as a breakthrough discovery for photovoltaic and photocatalytic applications. With mass spectrometry, we demonstrate the dynamics of hot electron transfers of anaerobic oxidization reactions on Au decorated TiO2 plasmonic nanoparticles, which were coated on the inner surface of a flask. Those nanoparticles were covered by continuously renewed liquid droplets of solvent and reactants that were transported through a Venturi jet mixer with auto-spray. In addition to intensive mass transfer in such droplet-based nanoreactors, as well as strong adsorption of reactants and rapid desorption of products on materials surfaces, the localized surface plasmon resonance (LSPR) excitation upon visible light illumination, by which accumulated energies of plasmons are transferred to electrons in the conduction band of the material, attributes to the efficient photocatalytic transformation. Mass spectrometric detection of intermediate radical anions and negative ions with stable isotope labeling unambiguously identifies that highly energetic hot electrons can escape from the plasmonic nanostructures, be collected by adsorbed molecules, and initiate bond cleavages. It was demonstrated that losses of two H atoms result in the anaerobic oxidization of each benzyl alcohol molecule to a benzyl aldehyde molecule in the absence of molecular oxygen with more than 90 % yields. The well recyclable plasmonic nanoreactors implicate the injection of transferred electrons eventually back to electronically depleted Au+ positive ions. Bridged by adsorbed molecules, electrons were repeatedly circulated back and forth in plasmonic nanoreactors, where the collected light was eventually converted into chemical energy.

Simultaneous degradation of microplastics and sludge during wet air oxidation

Microplastics (MPs) generated from daily life are commonly collected by urban sewage pipe networks and then transfer to sludge in wastewater treatment plants. Conventional biochemical treatment processes cannot degrade MPs effectively, causing an ecological risk via sludge land use. Wet air oxidation (WAO) is a promising sludge treatment technology with a strong ability to decompose complex organic matter, but its potential for the removal of MPs in sludge was unclear. In this study, three common MPs (polyethylene, polystyrene, and polyethylene terephthalate, which are called PEMPs, PSMPs, and PETMPs) were added into the sludge samples (1 g MP in 180 mL sludge), to test the effects of WAO on sludge and MPs. The results showed that WAO simultaneously degraded sludge and the PEMPs, and the two degradation processes were relatively independent when oxygen was supplied adequately. The dissolution of PSMPs and organic matter in sludge was not affected by each other, but the degradation rate was slowed down due to the interaction of ketones and benzene compounds. The hydrolysis of sludge and PETMPs was accelerated, while the hydrolyzed products such as terephthalic acid were oxidized without interfering with each other. No obvious MPs remained in the effluent, and volatile fatty acids (VFAs) were the main components, among which acetic acid accounted for 90%. When the sludge was treated with PEMPs, PSMPs, or PETMPs, the concentration of acetic acid finally accounted for 45%, 21%, and 18% of DOC. Overall, MPs can be degraded or even mineralized during sludge WAO, and humic acid derivatives, acetate, and other small molecules of alcohols, ketones, or aldehydes were the typical intermediates.

Specificity of internal rotation in aldehydes with three-membered rings

The results of anharmonic calculations of low-frequency vibrations of aldehyde molecules containing a three-membered cycle with a π-bond are presented. The theoretical exploration of the conformational behavior and geometrical structure of two related molecules is carried out and potential energy surface sections along the coordinates of internal rotation and non-planar vibration close in frequency are constructed and analyzed. The possibility of kinematic coupling of these two vibrations and the complexity of their forms are especially considered.

Overexpression of the aldehyde dehydrogenase AhALDH3H1 from Arachis hypogaea in soybean increases saline-alkali stress tolerance.

Soybean production is severely hampered by saline-alkaline stress caused by saline-alkalization. Plants have aldehydrogenase (ALDH) family members that convert reactive aldehydes to carboxylic acids to remove active aldehyde molecules. However, little is known about the increased saline-alkali tolerance caused by the ALDH function in soybean. Here, we introduced a previously identified ALDH coding gene AhALDH3H1 from Arachis hypogaea into the soybean genome to investigate its critical role in response to saline-alkali stress. Transgenic soybean with increased aldehyde dehydrogenase activity showed significant tolerance to saline-alkali stress. It reduced malondialdehyde (MDA) content compared to its receptor, suggesting that over-expression of AhALDH3H1 accelerated soybean tolerance to saline-alkali stress by increasing aldehyde dehydrogenase activity, which is responsible for scavenging toxic MDA. To further analyze the inner mechanisms that allow transgenic plants to tolerate saline-alkali stress, we sequenced the transcriptome and metabolome of P3 (wild type, WT) and transgenic lines which were separately treated with water and a saline-alkali solution. When subjected to saline-alkali stress, the integrated analysis of the transcriptome and metabolome suggested that several genes related to cell wall structure crucial for preserving cell wall extensibility and plasticity were largely responsible for restoring homeostasis within the transgenic cells compared to WT. Metabolites, including both necessary ingredients for cell wall genesis and harmful production produced during the saline-alkali stress response, could be transported efficiently with the help of the ABC transporter, reducing the negative effects of saline-alkali stress. These findings suggest that introducing AhALDH3H1 increases transgenic soybean tolerance to saline-alkali stress may through cell wall structure maintenance and metabolites transport.

Scale-up approach for the preparation of magnetic ferrite nanocubes and other shapes with benchmark performance for magnetic hyperthermia applications.

Magnetic nanoparticles are increasingly used in medical applications, including cancer treatment by magnetic hyperthermia. This protocol describes a solvothermal-based process to prepare, at the gram scale, ferrite nanoparticles with well-defined shape, i.e., nanocubes, nanostars and other faceted nanoparticles, and with fine control of structural/magnetic properties to achieve point-of-reference magnetic hyperthermia performance. This straightforward method comprises simple steps: (i) making a homogeneous alcoholic solution of a surfactant and an alkyl amine; (ii) adding an organometallic metal precursor together with an aldehyde molecule, which acts as the key shape directing agent; and (iii) reacting the mixture in an autoclave for solvothermal crystallization. The shape of the ferrite nanoparticles can be controlled by the structure of the aldehyde ligand. Benzaldehyde and its aromatic derivatives favor the formation of cubic ferrite nanoparticles while aliphatic aldehydes result in spherical nanoparticles. The replacement of the primary amine, used in the nanocubes synthesis, with a secondary/tertiary amine results in nanoparticles with star-like shape. The well-defined control in terms of shape, narrow size distribution (below 5%), compositional tuning and crystallinity guarantees the preparation, at the gram scale, of nanocubes/star-like nanoparticles that possess, under magnetic field conditions of clinical use, specific adsorption rates comparable to or even superior to those obtained through thermal decomposition methods, which are typically prepared at the milligram scale. Here, gram-scale nanoparticle products with benchmark features for magnetic hyperthermia applications can be prepared in ~10 h with an average level of expertise in chemistry.