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Mixtures of polyglycerol polyglycidyl ether (PGPE) and poly(ethylene glycol) diglycidyl ether (PEGDGE) with different molar ratios were cured with imine-containing phenolic hardeners prepared by the reactions of vanillin with ethylene glycol bis(3-aminopropyl) ether, diethylene glycol bis(3-aminopropyl) ether, and a polyetheramine (JEFFAMINE® ED-600) to produce bio-based epoxy cured products. Fourier-transform infrared spectroscopy (FT-IR) of the cured products revealed that the curing reaction of the epoxy and phenolic hydroxy groups was almost complete. The cross-linking density, glass transition temperature, and mechanical strength of the cured products decreased with decreasing the PGPE/PEGDGE ratio and increasing the oligoalkyleneoxy chain length of the phenolic hardeners. All cured products were healed three times at 100 °C under 2 MPa for 2 h. The healing efficiency, in terms of tensile strength, increased with decreasing PGPE/PEGDGE ratio and increasing oligoalkyleneoxy chain length. The polyetheramine-based cured product with the lowest PGPE/PEGDGE ratio exhibited the highest healing efficiency (94–97%), which only slightly decreased following repeated healing treatments. [ABSTRACT FROM AUTHOR]

Two series of vanillin derivatives containing 1,3,4-oxadiazole and 1,3-thiazolidin-4-one scaffolds were prepared and evaluated for their antifungal activity. The results revealed that compounds 6j (29.73 μg/ml) and 7a (38.15 μg/ml) displayed excellent inhibitory activity against the spore of Fusarium solani. The inhibitory activity of compound 7d (10.53 μg/ml) against the spore of Alternaria solani was more than 42-fold that of vanillin. Compound 7a (37.54 μg/ml) showed better antifungal activity against the spore of B. cinerea than positive controls. The cytotoxicity assay confirmed that compounds 6k, 7a, and 7d showed good selectivity and less toxicity to normal mammalian cells. [ABSTRACT FROM AUTHOR]

Vanillin is often used in food and medicine because of its unique flavor and pharmacological effects. However, excessive vanillin intake can harm human health; therefore, rapid and simple vanillin detection methods are required. In this study, porphyrin‐based conjugated microporous polymer‐grafted graphene (CMP‐rGO) was synthesized via the Sonogashira–Hagihara coupling reaction and assembled into an electrochemical sensor for vanillin detection. Due to the enhanced electrical conductivity and electrocatalytic characteristics of CMP‐rGO, the sensor demonstrated a low detection limit of 0.07 μM and a broad response range of 0.08–20 μM. Furthermore, this reusable sensor exhibited acceptable recoveries when evaluating vanillin in pharmaceuticals and human serum. This study offers technological assistance for the rapid detection of vanillin in pharmaceuticals and broadens the application of CMP‐rGO. [ABSTRACT FROM AUTHOR]

Developing recyclable and self-healing non-isocyanate polyurethane (NIPU) from renewable resources to replace traditional petroleum-based polyurethane (PU) is crucial for advancing green chemistry and sustainable development. Herein, a series of innovative cross-linked Poly(hydroxyurethane-urea)s (PHUUs) were prepared using renewable carbon dioxide (CO2) and vanillin, which displayed excellent thermal stability properties and solvent resistance. These PHUUs were constructed through the introduction of reversible hydrogen and imine bonds into cross-linked polymer networks, resulting in the cross-linked PHUUs exhibiting thermoplastic-like reprocessability, self healing, and closed-loop recyclability. Notably, the results indicated that the VL-TTD*-50 with remarkable hot-pressed remolding efficiency (nearly 98.0%) and self-healing efficiency (exceeding 95.0%) of tensile strength at 60 °C. Furthermore, they can be degraded in the 1M HCl and THF (v:v = 2:8) solution at room temperature, followed by regeneration without altering their original chemical structure and mechanical properties. This study presents a novel strategy for preparing cross-linked PHUUs with self-healing and closed-loop recyclability from renewable resources as sustainable alternatives for traditional petroleum-based PUs. [ABSTRACT FROM AUTHOR]

Protein engineering is crucial to improve enzymes' efficiency and robustness for industrial biocatalysis. NOV1 is a bacterial dioxygenase that holds biotechnological potential by catalyzing the one-step oxidation of the lignin-derived isoeugenol into vanillin, a popular flavoring agent used in food, cleaning products, cosmetics and pharmaceuticals. This study aims to enhance NOV1 activity and operational stability through the identification of distal hotspots, located at more than 9 Å from the active site using Zymspot, a tool that predicts advantageous distant mutations, streamlining protein engineering. A total of 41 variants were constructed using site-directed mutagenesis and the six most active enzyme variants were then recombined. Two variants, with two and three mutations, showed nearly a 10-fold increase in activity and up to 40-fold higher operational stability than the wild-type. Furthermore, these variants show 90–100 % immobilization efficiency in metal affinity resins, compared to approximately 60 % for the wild-type. In bioconversions where 50 mM of isoeugenol was added stepwise over 24-h cycles, the 1D2 variant produced approximately 144 mM of vanillin after six reaction cycles, corresponding to around 22 mg, indicating a 35 % molar conversion yield. This output was around 2.5 times higher than that obtained using the wild-type. Our findings highlight the efficacy of distal protein engineering in enhancing enzyme functions like activity, stability, and metal binding selectivity, thereby fulfilling the criteria for industrial biocatalysts. This study provides a novel approach to enzyme optimization that could have significant implications for various biotechnological applications. [Display omitted] • NOV1 catalyzes the one-step coenzyme-free formation of vanillin from isoeugenol. • Computational tools predicted beneficial mutations distal from active site. • Distal mutations significantly enhance NOV1 activity and stability properties. • Distal mutations improved immobilization efficiency in metal affinity resins. • Our study emphasizes distal interactions' role in enhancing enzymatic properties. [ABSTRACT FROM AUTHOR]

The corrosion-inhibiting effect of vanillin molecule (VAN) and its protonated ( VANH + ) and deprotonated ( VAND - ) forms was investigated to evaluate the relationship between molecule structures and their associated efficiencies using density functional theory (DFT). The primary objective is to establish a comprehensive understanding of the relationship between molecular structures and their corrosion-inhibiting efficiencies. Global and local reactivity descriptors based on conceptual density functional theory (DFT), including the highest occupied molecular orbital energy (EHOMO), the lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔEgap), global hardness (η), global softness (σ), global electrophilicity (ω), electro-donating power ( ω - ), electro-accepting power ( ω + ), and Hirshfeld Fukui indices, have been investigated. The central aim of the present study is to elucidate the adsorption mechanism and provide a clear understanding of how these inhibitors interact with the Al(111) surface under different conditions. Molecular dynamics simulations in solid-state physics were employed to explore the adsorption mechanism of inhibitors in their neutral, protonated, and deprotonated species onto the Al(111) surface. The predicted adsorption suggests that the studied inhibitors for both parallel and perpendicular orientations decrease in the order VAND - > VAN > VANH + . The VAN molecule can adsorb on the Al(111) surface in various orientations, both parallel and perpendicular, as well as using different sides of the molecule. The parallel adsorption of VAN and VAND - inhibitors on the Al(111) surface occurs primarily due to the creation of an Al‒O bond, while the VANH + form adheres to the Al(111) surface through the formation of an Al‒C bond. Furthermore, the adsorption of the neutral VAN on the Al(111) surface is not only via the oxygen atom but also through the carbon C7 atom of the carbonyl group. [ABSTRACT FROM AUTHOR]

Consumers' growing knowledge of healthy, environmentally friendly flavors and scents drives the demand for vanillin bioproduction. To save costs on nitrogen during the bioproduction of vanillin, this study investigated the feasibility of using corn steep as a substitute. Using the response surface methodology (RSM) model, the synergistic effects of three variables on vanillin yield were evaluated using Box–Behnken design (BBD). When corn steep liquid, ferulic acid concentration, and pH were 7.72 g/L, 2.33 g/L, and 9.34, respectively, the highest vanillin production of 386 mg/L was achieved. The findings indicated that a maximum overall desirability (D) of 1.0 and a significant (p < 0.05) quadratic model with a regression coefficient (R2) of 0.995 can be used to establish ideal circumstances for the bioproduction of vanillin. This study demonstrated the effectiveness of using corn steep liquor as a low-cost nitrogen source in the medium formulation for the extraction and production of vanillin. [ABSTRACT FROM AUTHOR]

In this study, the vanilla extract was hydrolyzed by β-glucosidase and the enzymatic hydrolysis conditions were investigated, in order to explore the enzymatic fragrance production process of vanilla extract. The vanilla extract was prepared by Soxhlet extraction method using ethanol as extraction solvent. On the basis of single factor experiments, the enzymatic fragrance production process was optimized using orthogonal experiment, and the vanillin contents were measured by high performance liquid chromatography (HPLC). The results showed that the optimal enzymatic fragrance production conditions were determined as follows: enzyme amount of 62.5 U/g, hydrolysis temperature of 35 °C, hydrolysis time of 26 h, and material-liquid ratio of 1:8 (g/mL). Under these conditions, the vanillin content in the extract was the highest. These results indicate that the enzymatic process can significantly increase vanillin content in vanilla extract, which has the potential values of production and application. [ABSTRACT FROM AUTHOR]

Plantar fasciitis is the most common cause of heel pain in adults with an overall prevalence of 0.85% in the adult population of the US, affecting over 2 million adults annually. Most current treatment modalities are not supported by sufficient evidence to recommend one particular strategy over another. Topical application of analgesics for soft tissue pain is well established, however the plantar fascia presents challenges in this regard due to thick skin, fibrotic tissue, and an often thickened fat pad. Sixty-two patients with plantar fasciitis were randomized to a placebo controlled trial testing the efficacy of a topical solution of plant terpenes containing camphor, menthol, eugenol, eucalyptol, and vanillin. Skin permeation of the mixture was enhanced with 15% dimethylsulfoxide (DMSO), 1% limonene, and rosemary oil. One ml of solution was applied topically twice daily, and pain scores evaluated on Day 0, Day 1, Day 3, and Day 10. Using the validated foot function index 78.1% of patients reported an 85% or greater decrease in their total pain score by day 10 while placebo treatment was without effect (One Way ANOVA, P < 0.01). This study adapts the treatment modality of topical analgesia for soft tissue pain to a problematic area of the body and shows therapeutic promise. ClinicalTrials.gov Identifier: NCT05467631 [ABSTRACT FROM AUTHOR]

In order to study the flavoring effect of milk-flavored gel filter rod in cigarettes, a GC-MS analytical method was established, the pretreatment conditions were optimized, and the transfer rates of the characteristic components in milk-flavored gel filter rod cigarettes were investigated. The results showed that the optimal extraction conditions: anhydrous ethanol was used as the solvent, the extraction volume was 10 mL, and the ultrasonic extraction time was 60 min; the sample adding recovery rates of five characteristic components (vanillin, ethyl vanillin, veratraldehyde, anisyl alcohol, anisyl acetate) in the milk-flavored gel filter rod were 94.1%-104.1%, and the detection limits were 0.118.23 µg/mL, with a quantification limit of 0.25-27.42 µg/mL. The transfer rates of the five characteristic components were divided into three gradients. The transfer rates of vanillin and ethyl vanillin to the mainstream flue gas particulate matter were higher, at 8.44% and 8.14%, respectively, followed by anisyl alcohol (5.42%) and anisyl acetate (4.35%), the transfer rate of veratraldehyde was the lowest, at 2.44%. The filter tip retention rate of the five characteristic components was 85.31%-90.37%, indicating that most of the characteristic components were trapped in the filter tip under the gel flavoring mode. The vanillin content in the filter tip and the transfer rate of vanillin in the mainstream smoke particles decreased rapidly 180 days before being placed in the natural environment, and showed a gradual decline trend 180-360 days after being produced, indicating that 180 days after being produced was the best time for smoking milk-flavored gel filter rod cigarettes. Under the condition of constant temperature and humidity, the vanillin content in the filter tip and the transfer rate of vanillin in the particulate matter of mainstream smoke were higher than those in the natural ventilation environment, indicating that milk-flavored gel filter rod cigarettes were best stored in the environment with relatively constant temperature and humidity. [ABSTRACT FROM AUTHOR]

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This work includes the synthesis of new pyrazoline derivatives 6-20 over two steps. The first step included a condensation between vanillin and various aromatic ketones (acetophenone, p-nitroacetophenone, p-chloroacetophenone, pbromoacetophenone, and 2-acetylnaphthalene) to provide the corresponding chalcone derivatives 1-5 in high yields (up to 93%). The second step involved a reaction of 1- 5 with hydrazine hydrate, phenyl hydrazine, and p-nitrophenyl hydrazine, which gave the desired products 6-20 in yields ranging from 60 to 85%. The structures of the prepared compounds were confirmed by FT-IR and 1H NMR spectroscopy. A few of the produced compounds were tested for antibacterial and antioxidant properties. [ABSTRACT FROM AUTHOR]

Vanillin is one of the most important flavoring agents worldwide. Currently, consumers' awareness and concern for biovanillin production has been increasing. This study aimed to screen the potential of clove rhizospheric bacteria isolates producing vanillin through a biotransformation process of eugenol and to conduct the preliminary optimization of the biotransformation condition. Twenty-eight bacteria isolates were screened for their capability to transform eugenol into vanillin. BKL 15 isolate, which was identified as Lysinibacillus xylanilyticus, was selected as the highest vanillin producer among the isolates. The optimum molar yield of vanillin produced by the selected isolate was 4.99% (1.11 g/L) after 168 hours of biotransformation process in the medium consisting of TSB (30 g/L), eugenol (24 g/L), yeast extract (20 g/L), and concentration of casamino acid (20 g/L). Throughout the publications we have read, this is the first report of L. xylanolyticus that produces vanillin. [ABSTRACT FROM AUTHOR]

Gambiered Guangdong gauze is the only silk fabric in the world that is dyed with plants. In its processing the silk fabric is repeatedly impregnated in Dioscorea cirrhosa Lour extract and exposed to the sun for dozens of times and then coated with the pollution-free river mud in Guangdong province. After full reaction the excessive river mud is washed away and dried. It takes four weeks to complete the production. Due to its pure handmade long production cycle and limited annual production in Guangdong the market price of gambiered Guangdong gauze is relatively high. At present the printing and dyeing process of synthetic dyes has appeared in the market to imitate gambiered Guangdong gauze in order to seek high profits which has caused unnecessary economic losses to ordinary consumers and employees. However there is a lack of objective and efficient methods of identifying Gambiered Guangdong gauze in the market. To identify the authenticity of Gambiered Guangdong gauze reduce the economic losses of consumers and practitioners and standardize the sales market of Gambiered Guangdong gauze three kinds of aromatic aldehydes including vanillin 4-methoxycinnamaldehyde and 4- dimethylamino cinnamaldehyde were used to formulate an identification reagent to identify Gambiered Guangdong gauze. Firstly the color change of the identification reagent was observed after its reaction with the Dioscorea cirrhosa Lour solution and the mechanism of the color reaction was investigated by UVabsorption spectrum and infrared spectrum. Subsequently based on the color and absorbance changes of the chromogenic reaction the optimum reaction conditions for the identification reagent were explored. Finally the reagent was added onto the surface of the authentic Gambiered Guangdong gauze the color change of the silk surface was observed and the K/ S of the silk surface was measured. In this paper the developed identification reagent was applied to the authentification identification of Gambiered Guangdong gauze. Combined with the color of silk surface and the change of K/ S the authenticity identification of Gambiered Guangdong gauze was realized. The experimental results indicated that after reacting with vanillin 4-methoxycinnamical and 4- dimethylamino cinnamaldehyde identification reagents the color of Dioscorea cirrhosa Lour pigment changed to pink magenta and black respectively. New peaks were generated in the UV-Vis at 500 nm 510 nm and 640 nm respectively. In the FTIR new absorption peaks were generated at 1 045 cm-1 and 1 428 cm-1 in vanillin group 2 857 cm-1 and 2 927 cm-1 in 4-methoxycinnamaldehyde group and 1 680 cm-1 in 4- dimethylamino cinnamaldehyde group and all three groups generated new absorption peaks near 1 724 cm-1 . The analysis of UV-Vis and FTIR of the reaction products showed that the phenolic condensation reaction occurred between aromatic aldehyde identification reagents and Dioscorea cirrhosa Lour pigment which changed the color structure of the pigment. The optimal reaction conditions for identification reagent are follows a mass fraction of 0. 2% a pH value of 1. 4 a reaction temperature of 40 ℃ and a reaction time of 10 minutes. Based on the optimal reaction conditions the identification reagent was added to the surface of the authentic Gambiered Guangdong gauze the color of the authentic silk surface was darker and the K/ S increased from 5. 13 to 6. 68. The color of the genuine Gambiered Guangdong gauze became lighter and the K/ S decreased from 6. 26 to 5. 33. The method of this article can be used to identify the authenticity of Gambiered Guangdong gauze by identifying the color changes after reacting with reagents which proves the validity of the method. [ABSTRACT FROM AUTHOR]

Vanilla is one of the most widely used flavors in the food and beverage industry; however, it is thermally unstable and volatile. In this study, microparticles consisting of ternary complexes of vanillin/γ-cyclodextrin/dextran (V/C/D) were prepared, in which vanillin served as a crosslink between the γ-cyclodextrin and dextran. One end of vanillin was inserted into the interior of γ-cyclodextrin through hydrophobic interactions and hydrogen bonding, while the other end was bound to dextran through hydrogen bonding. The encapsulation efficiency of vanillin in the microparticles increased from around 59 to 92% when the mass ratio of dextran in the complexes increased (V/C/D ratio ranging from 1:9:0 to 1:5:4). Moreover, the crystallization peak of vanillin disappeared in complexes with higher dextran contents. The dispersibility of vanillin in cold water (4 ℃) increased as the dextran content in the complexes increased, with the highest value being 15 mg/mL. Encapsulation of vanillin within the microparticles protected it from volatilization during storage, with more than 90% being retained after holding at 60 ℃ for a month, as well as increasing its resistance thermal processing. The release of vanillin during baking (200 ℃, 30 min) could be controlled by altering the composition of the microparticles. Our findings provide a novel strategy for improving the stability and controlling the release of aromas. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to synthesize two different benzoxazines (Bz) monomers using bio-based and petroleum-based primary amines, respectively, and they have been compared to study their thermal and mechanical performances. Design/methodology/approach: A bio-based bisphenol, Divanillin (DiVa), was formed by reacting two moles of vanillin with one mole of ethylenediamine (EDA) which was then reacted firstly with paraformaldehyde and EDA to form the benzoxazine DiVa-EDA-Bz, and secondly with paraformaldehyde and furfuryl amine (FFA) to form the benzoxazine DiVa-FFA-Bz. The molecular structure and thermal properties of the benzoxazines were characterized by fourier transform infrared spectroscopy and nuclear magnetic resonance (1H,13C) spectroscopies, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The benzoxazines were further coated on mild steel panels to evaluate their mechanical properties and chemical resistance. Findings: The DSC results of DiVa-FFA-Bz showed two exothermic peaks related to crosslinking compared to the one in DiVa-EDA-Bz. The DiVa-FFA-Bz also showed a higher heat of polymerization than DiVa-EDA-Bz. The TGA results showed that DiVa-FFA-Bz exhibited higher thermal stability with a residual char of 54.10% than 43.24% for DiVa-EDA-Bz. The chemical resistance test results showed that DiVa-FFA-Bz showed better chemical resistance and mechanical properties due to its higher crosslinking density. Originality/value: This study shows the use of bio-based materials, vanillin and FFA, for synthesizing a benzoxazine resin and its application at high temperatures. [ABSTRACT FROM AUTHOR]

The addition of oak chips is one of the basic techniques for artificial aging of brandy, but its effect on mulberry brandy flavor is unknown. In this study, the effect of oak chips addition on the aging of mulberry brandy and the evolution of volatile compounds during the aging process were investigated using flavoromics techniques. The results showed that the 15 g/l oak chips had the highest ethyl acetate content and the highest sensory scores at 30 °C aging conditions, with the tannin and total phenol contents at 233.7 ± 6.4 mg/l and 15.83 ± 1.18 mg/l, respectively. Through Partial least squares discriminant analysis (PLS-DA) and correlation analysis, 12 essential compounds during aging were identified, among which Ethyl acetate, Whiskey lactone, Furfural, and Vanillin also showed a positive correlation with aroma intensity, positively influencing the quality of mulberry brandy, resulting in a richer brandy flavor. The results of the study provide a theoretical basis and reference for the artificial aging technology of mulberry brandy. [ABSTRACT FROM AUTHOR]

This study investigates the chemical–physical properties and anticorrosion effectiveness of UV‐cured coatings produced using epoxidized vanillin (DGEVA) as biobased precursor, then reinforced by the addition of nanoclay. After optimizing the UV‐curing parameters of three different formulations by Fourier transform infrared spectroscopy (FTIR), the thermo‐mechanical properties of the coatings are assessed by differential scanning calorimetric analysis (DSC), dynamic thermal mechanical analysis (DTMA), and pencil hardness. The coatings are applied on mild steel substrates and then their barrier properties are investigated by electrochemical impedance spectroscopy measurements, immersing the samples in 3.5 wt% NaCl aerated solutions. The results show the good corrosion protective effectiveness of the biobased coatings. The nanoclay addition has a beneficial effect, as it hinders the diffusion of the aggressive ions from the electrolyte solution to the metal substrate. The reported findings demonstrate the possibility of using biobased precursors and UV‐curing technology to reduce the environmental impact of the coating industry. [ABSTRACT FROM AUTHOR]

Mesoporous zirconium oxides (ZrO2) and cobalt oxides (CoxOy) were prepared by different methods, using vanillin (VAN) as a model compound to explore the catalytic performance of catalysts for the hydrodeoxygenation (HDO) reaction. Various characterization methods were used to test the catalysts' morphology, structure, and chemical composition. Under the optimal conditions, the study found that the yield of catalyzing the HDO of VAN to 2-methoxy-4-methylphenol (MMP) is 99%, with ZrO2 prepared by the precipitation method as the catalyst, isopropanol as the solvent, hydrogen pressure of 5 MPa, reaction time of 24 h, and reaction temperature of 180 °C. A high methylcyclohexanol (MCYL) yield of 99% was obtained for the HDO of VAN, with CoxOy prepared by the precipitation method as the catalyst, isopropanol as the solvent, hydrogen pressure of 4 MPa, reaction time of 24 h, and reaction temperature of 170 °C. [ABSTRACT FROM AUTHOR]

Hg(II) and Co(II) complexes of vanillin VanH, namely, [Hg(van)2]. 1.5H2O and [Co(van)2]. 5.5H2O were prepared. The complexes were characterized by elemental analyses, Fourier transform infrared spectra and thermal techniques. The molecular geometries of the compounds were fully optimized with density functional theory computations using the B3LYP/LANL2DZ method. To determine the reactivity and possible electrophilic and nucleophilic sites, frontier molecular orbital energies, global reactivity, molecular electrostatic potential, Mullikan and NBO charges were calculated using the same method. The obtained results indicate that the compound possesses good kinetic stability. The thermal decomposition kinetics of the complexes were studied by the TG and DTG methods. The kinetic parameters, activation entropy, and activation free energy were also calculated using the Coats Redfern method. The photocatalytic activity was evaluated by the degradation of methyl orange aqueous solution under UV irradiation. [ABSTRACT FROM AUTHOR]

The development of ethylcellulose-based polymeric microsponges for the topical delivery of therapeutic agents has attracted the interest of pharmaceutical scientists around the globe in recent years. This work represents preparation, optimization (using Box–Behnken design [BBD]), and characterization (in-vitro and ex-vivo) of ethylcellulose microsponges loaded with vanillin for effective topical delivery to treat wounds. Vanillin-ethylcellulose microsponges were prepared by using quasi-emulsion solvent diffusion and optimized formulation (F9) (containing 100 mg ethylcellulose, 10 mL dichloromethane, 100 mg vanillin, and 90 mg polyvinyl alcohol) developed showed particle size (90.3 ± 2.9 µm), high entrapment of vanillin (79.0 ± 2.8%), and optimum colloidal properties (zeta potential = −37.91 ± 2.44 mV; polydispersity index (PDI) = 0.224 ± 0.23). Optimized formulation extended the release of vanillin (96.68 ± 3.11%) in-vitro for 24 h. Vanillin-ethylcellulose microsponges (F9) dispersed in Carbopol 940 gel showed limited ex-vivo skin permeation (steady-state flux, JSS = 243.7 ± 6.2 µg/cm2/h) and higher skin retention (82.46 ± 6.74%) for 24 h in pig ear skin compared to plain vanillin Carbopol 940 gel (steady-state flux, JSS = 1350 ± 10.8 µg/cm2/h, skin retention = 33.66 ± 4.53%). Results of confocal laser scanning microscopy (CLSM) of Vanillin-ethylcellulose microsponges (F9) Carbopol 940 gel revealed accumulation of microsponges in the stratum corneum layer of skin as a depot. Microsponges-based Carbopol 940 gel also displayed excellent in-vitro antibacterial activity (zone of inhibition = 24.2 ± 1.3 mm) against Staphylococcus aureus for 24 h compared to plain vanillin Carbopol 940 gel (zone of inhibition = 10.30 ± 1.2 mm) that was considered good for its wound healing activity. Therefore, developed vanillin-loaded ethylcellulose microsponges could be effectively used in the treatment of wounds by reducing side effects associated with vanillin and promoting its localized delivery in Carbopol 940 gel form. [ABSTRACT FROM AUTHOR]

The thermotolerant yeast Pichia kudriavzevii (previously known as Issatchenkia orientalis), can produce ethanol from a variety of carbon sources and grows at around 45 °C. Thus, this yeast is considered a useful biocatalyst for producing ethanol from lignocellulose through simultaneous saccharification and fermentation (SSF). SSF has several advantages, such as a simplified manufacturing process, ease of operation and reduced energy input. Using P. kudriavzevii NBRC1279 and NBRC1664, we previously succeeded in producing ethanol through SSF; however, the extent to which inhibitors by-produced from lignocellulose hydrolysis affect the growth and ethanol productivity of the two strains remains to be investigated. In this study, to better understand the inhibitor tolerance capacity of the two strains, spot assay, growth experiment, real-time quantitative PCR (RT-qPCR) analysis and multiple sequence alignment analysis were carried out. When P. kudriavzevii NBRC1279 and NBRC1664, as well as Saccharomyces cerevisiae BY4742 as a control, were cultured on SCD plates containing 17% ethanol, 42 mM furfural, 56 mM 5-hydroxymethylfurfural (HMF) or 10 mM vanillin, only P. kudriavzevii NBRC1664 was able to grow under all conditions. Moreover, the inhibitor tolerance capacity of P. kudriavzevii NBRC1664 was greater than those of other strains using SCD medium containing the same concentrations of various inhibitors. When an RT-qPCR analysis of seven gene sequences from aldehyde dehydrogenase and the aldehyde dehydrogenase family protein (ADHF) was performed using P. kudriavzevii NBRC1664 cultivated in the presence of 56 mM HMF, ADHF1 and ADHF2 were up-regulated in the early logarithmic growth phase. Moreover, a multiple sequence alignment of the amino acid sequences of ADHF1, ADHF2 and the known ADH suggested that ADHF1 and ADHF2 may catalyze the reversible NAD+-dependent oxidation of HMF. Our data may be useful for future studies on the metabolic engineering of more useful strains for ethanol production from lignocellulose. [ABSTRACT FROM AUTHOR]

Many studies have suggested that the encapsulation of natural antimicrobials increases their antimicrobial activity. In this sense, the objective was to study the inactivation of microorganisms with encapsulated cinnamaldehyde and vanillin (E-CIN and E-VN), in comparison with the unencapsulated antimicrobials (CIN and VN) in protein beverages. Additionally, the microbial response was quantified through mathematical modeling. Cinnamaldehyde and vanillin were encapsulated using whey protein concentrate (WPC) as the encapsulating agent. The effectiveness at inactivating Escherichia coli, Listeria innocua, and Saccharomyces cerevisiae was evaluated in a protein-apple juice beverage during storage (4 °C). Encapsulation increased the effectiveness of cinnamaldehyde, reaching reductions of 1.8, 3.3, and 5.3 log CFU/mL in E. coli, L. innocua, and S. cerevisiae, respectively, while vanillin encapsulation had little effect on antimicrobial activity, reducing by 0.5, 1.4, and 1.1 log cycles, respectively. The combined treatments (E-CIN + E-VN) had an additive effect in reducing E. coli and a synergistic effect against S. cerevisiae. The Gompertz model was more versatile and better described the biphasic curves, whereas the Weibull model complemented the information regarding the spectrum of resistances within the microbial population. In conclusion, the encapsulation of cinnamaldehyde with WPC enhanced its activity. However, further studies are necessary to improve the antimicrobial activity of vanillin. [ABSTRACT FROM AUTHOR]

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is the main component of natural vanilla and a relevant substance in the flavoring and aromatic industries. This study presents a kinetic model to explain both vanillin and vanillic acid concentrations achieved in the alkaline oxidation of pine kraft lignin. Considering that they come from the same precursors, this approach allows an understanding of vanillin production with reaction conditions that minimize the vanillic acid pathway directly from the lignin oligomers, thus maximizing vanillin production. This study involves the effects of oxygen partial pressure, temperature, and the presence or absence of a catalyst (CuSO4 and Fe2(SO4)3 mixture) on the vanillin and vanillic acid yields. An adapted reactor (M/K Systems Inc., Williamstown, MA, USA) with a recirculation and spray liquids system was used in the experiments. The experiments were performed using one liter of a solution of NaOH 2 M and 60 g of lignin. During the lignin oxidation reaction, liquid samples were analyzed at different times (from 0 to 200 min). The oxidation products were quantified by liquid chromatography (HPLC). The catalyzed experiments presented higher maximum vanillin yields than the non-catalyzed ones (39.2–39.6% on nitrobenzene oxidation) achieved at 150 °C. A kinetic model is proposed where the kinetic parameters were estimated using Monte Carlo methods, fitting satisfactorily to the experimental results. The statistical analysis of the kinetic parameters showed that all the studied variables significantly affect the vanillin yield. [ABSTRACT FROM AUTHOR]

Herein, we introduced a nitrogen-alkali lignin-doped phenolic resin (N@ALnPR) to produce palladium nanoparticles through an in situ reduction of palladium in an aqueous phase, without the need for additional reagents or a reducing atmosphere. The phenolic resin nanospheres and the resulting palladium nanoparticles were extensively characterized. Alkali lignin created a highly conducive environment for nitrogen incorporation, dispersion, reduction, and stabilization of palladium, leading to a distinct catalytic performance of palladium nanoparticles in vanillin hydrodeoxygenation. Under specific conditions of 1 mmol of vanillin, 40 mg of catalyst, 1 MPa H2, 90 °C, and 3 h, the optimized Pd/N@AL30PR catalyst exhibited a nearly complete conversion of vanillin, 98.9% selectivity toward p-creosol, and good stability for multiple reuses. Consequently, an environmentally friendly lignin-based catalyst was developed and used for the efficient hydrodeoxygenation conversion of lignin-based platform compounds. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful construction of Pd/WO 3-x heterostructures. • Strong photoabsorption and high photothermal efficiency. • Efficient interfacial charge transfer and utilization of hot carriers. • High reactivity and selectivity for hydrodeoxygenation of vanillin under sunlight. The selective hydrodeoxygenation (HDO) of sustainable lignocellulosic biomass plays a pivotal role in the conversion of biomass into high-value fuels and chemicals. Nevertheless, HDO for biomass upgrading always demands high temperatures and high hydrogen (H 2) pressure. Photothermal catalysis has been recognized as an effective approach for boosting chemical reactions under mild conditions while maintaining superior selectivity. Herein, we report the design of palladium-decorated defective tungsten oxide (Pd/WO 3-x) catalysts with enhanced photothermal catalytic performances for the efficient HDO of vanillin. Pd/WO 3-x nanoflowers have been synthesized through a solvothermal/ in-situ reduction two-step strategy, and they exhibit notable photoabsorption in a wide range (200–1100 nm), high photothermal conversion and efficient charge separation efficiency. Under simulated sunlight irradiation (0.3 W cm−2), Pd/WO 3-x exhibits a maximum vanillin conversion up to 86.8 % with a 2-methoxy-4-methylphenol (MMP) selectivity of 100 %, which is obviously higher than that (vanillin conversion = 33.1 %, MMP selectivity = 100 %) in the oil bath at the same temperature. Such higher conversion efficiency and selectivity under sunlight should result from the synergistic integration of hot electrons and photothermal heating, both of which are derived from localized surface plasmon resonance (LSPR) in WO 3-x. Importantly, Pd/WO 3-x catalyst demonstrates good stability and high selectivity to MMP even after 5 cycles. This work may offer a novel viewpoint on the advancement of photothermal catalysts and the realization of photothermal catalytic biomass conversion under mild conditions. [ABSTRACT FROM AUTHOR]

This study presents a solvent-free, facile synthesis of a bio-based green antibacterial agent and aromatic monomer methacrylated vanillin (MV) using vanillin. The resulting MV not only imparted antibacterial properties to coatings layered on leather, but could also be employed as a green alternative to petroleum-based carcinogen styrene (St). Herein, MV was copolymerized with butyl acrylate (BA) to obtain waterborne bio-based P(MV–BA) miniemulsion via miniemulsion polymerization. Subsequently, MXene nanosheets with excellent photothermal conversion performance and antibacterial properties, were introduced into the P(MV–BA) miniemulsion by ultrasonic dispersion. During the gradual solidification of P(MV–BA)/MXene nanocomposite miniemulsion on the leather surface, MXene gradually migrated to the surface of leather coatings due to the cavitation effect of ultrasonication and amphiphilicity of MXene, which prompted its full exposure to light and bacteria, exerting the maximum photothermal conversion efficiency and significant antibacterial efficacy. In particular, when the dosage of MXene nanosheets was 1.4 wt%, the surface temperature of P(MV–BA)/MXene nanocomposite miniemulsion-coated leather (PML) increased by about 15 °C in an outdoor environment during winter, and the antibacterial rate against Escherichia coli and Staphylococcus aureus was nearly 100% under the simulated sunlight treatment for 30 min. Moreover, the introduction of MXene nanosheets increased the air permeability, water vapor permeability, and thermal stability of these coatings. This study provides a new insight into the preparation of novel, green, and waterborne bio-based nanocomposite coatings for leather, with desired warmth retention and antibacterial properties. It can not only realize zero-carbon heating based on sunlight in winter, reducing the use of fossil fuels and greenhouse gas emissions, but also improve ability to fight off invasion by harmful bacteria, viruses, and other microorganisms.

Abstract Background Vanillin is a flavoring substance derived from vanilla. We are currently developing a biotransformation method for vanillin production using glucose. This report describes the last step in vanillin production: the conversion of vanillic acid to vanillin. First, we selected Corynebacterium glutamicum as the host owing to its high vanillin resistance. The aromatic aldehyde reductase gene (NCgl0324) and vanillic acid demethylase protein subunits A and B gene (vanAB, NCgl2300-NCgl2301) were deleted in C. glutamicum genome to avoid vanillin degradation. Next, we searched for an aromatic carboxylic acid reductase (ACAR), which converts vanillic acid to vanillin. Seventeen ACAR homologs from various organisms were introduced into C. glutamicum. Results In vivo conversion experiments showed that eight ACARs were successfully expressed and produced vanillin. In terms of conversion activity and substrate specificity, the ACARs from Gordonia effusa, Coccomyxa subellipsoidea, and Novosphingobium malaysiense are promising candidates for commercial production. Conclusions Corynebacterium glutamicum harboring Gordonia effusa ACAR produced 22 g/L vanillin, which is, to the best of our knowledge, the highest accumulation reported in the literature. At the same time, we discovered ACAR from Novosphingobium malaysiense and Coccomyxa subellipsoidea C-169 with high substrate specificity. These findings are useful for reducing the byproducts.

Background and objective: Sulfonamides are a type of antibiotic that are used to treat several infections caused by microorganisms. Sulfonamides are bacteriostatic, meaning they prevent bacterial growth. This study aimed to produce compounds with better antimicrobial activity. Methods: By condensation reaction, Schiff bases were synthesized from sulfonamides (sulfamethoxazole, sulfapyridine, sulfathiazole, sulfadiazine and sulfisoxazole) and vanillin to enhance antimicrobial activity of synthesized compounds. The agar dilution method was used to measuring the minimum inhibition concentration (MIC) of synthesized compounds. Results: The synthesized compounds were characterized by FT-IR, 1H-NMR, 13C-NMR and tested for the antibacterial activity against gram positive bacteria (Staphylococcus aureus), gram negative bacteria (Escherichia coli) and antifungal activity against (Candida albicans). Ciprofloxacin and Fluconazole used as standard drugs for bacteria and fungi. Conclusion: The Schiff base was synthesized, characterized, and exhibited enhanced antimicrobial and antifungal activities.

The objective of this study was to develop and characterize a novel hyaluronic acid (HA) 3D scaffold integrated with gelatin microparticles for sustained-delivery applications. To achieve this goal, the delivery microparticles were synthesized and thoroughly characterized, focusing on their crosslinking mechanisms (vanillin and genipin), degradation profiles, and release kinetics. Additionally, the cytotoxicity of the system was assessed, and its impact on the cell adhesion and distribution using mouse fibroblasts was examined. The combination of both biomaterials offers a novel platform for the gradual release of various factors encapsulated within the microparticles while simultaneously providing cell protection, support, and controlled factor dispersion due to the HA 3D scaffold matrix. Hence, this system offers a platform for addressing injure repair by continuously releasing specific encapsulated factors for optimal tissue regeneration. Additionally, by leveraging the properties of HA conjugates with small drug molecules, we can enhance the solubility, targeting capabilities, and cellular absorption, as well as prolong the system stability and half-life. As a result, this integrated approach presents a versatile strategy for therapeutic interventions aimed at promoting tissue repair and regeneration. [ABSTRACT FROM AUTHOR]

3D printing is a low cost, customizable, and fast‐growing technology with the potential to revolutionize plastic manufacturing. Vat photopolymerization 3D printing technologies stand out for their high resolution, however, the resulting printed materials are made from petroleum feedstocks and are covalently crosslinked which renders them unrecyclable. Here, resin formulations with 70 wt% bio‐based content and dynamic functionality are synthesized and printed using lignin, vanillin, and soybean oil components. These printed polymers can undergo dynamic transesterification due to the methacrylated lignin (LMA) to allow for self‐healing capabilities; therefore, potentially increasing the materials lifetimes compared to traditional thermoset materials, offsetting the use of traditional petroleum‐based resins, and lowering their environmental impact. The LMA also provides the thermosets with better mechanical performance and thermal stability in comparison to the controls. Additionally, compatibility with 3D printing technologies improves the competitiveness of biobased plastics with conventional materials. [ABSTRACT FROM AUTHOR]

Vanillin crystals undergo needle-like morphology that results in poor flowability, crystal breakage, and low packing density. The spherical crystallization technology can produce particles with improved flowability and stability. A reverse antisolvent crystallization based on liquid-liquid phase separation is proposed in this work to produce vanillin spherical agglomerates. Hansen Solubility Parameters are applied to explain the liquid-liquid phase separation (LLPS) phenomenon. The Pixact Crystallization Monitoring system is applied to in-situ monitor the whole process. A six-step spherical crystallization mechanism is revealed based on the recorded photos, including the generation of oil droplets, nucleation inside oil droplets, the coalescence and split of oil droplets, crystal growth and agglomeration, breakage of oil droplets, and attrition of agglomerates. Different working conditions are tested to explore the best operation parameters and a frequency-conversion stirring strategy is proposed to improve the production of spherical crystals. [ABSTRACT FROM AUTHOR]

Objective: A sequence of biologically active vanillin acetamides bearing heterocyclic moiety (VHAs) specifically vanillin isoniazid acetamide (VISO), vanillin-2-pyridine acetamide (V2PR), vanillin-4-pyridine acetamide (V4PR), and vanillin-2-pyrimidine acetamide (V2PM) are synthesized and methodically characterized by spectroscopic techniques such as Nuclear Magnetic Resonance (1H and 13C NMR), Electrospray Ionization Mass, Fourier Transform Infrared and Ultraviolet-Visible spectroscopy. Further, the VHAs are inspected for in vitro biological activities such as anti-inflammatory by protein anti-denaturation, antidiabetic by enzyme inhibition method and the in vitro results are linked with the reference drug. Methods: To the acetonitrile solution of intermediate TBTU and trimethylamine is added at room temperature. The reaction mixture is stirred for 30 min and then the corresponding amine is added. The reaction mixture is stirred for 4 h and the reaction mixture is extracted with ethyl acetate. The evaporation of the solvent yielded the VHAs. The anti-inflammatory activity of VHAs is tested disbursing the Bovine serum albumin denaturation technique. The antidiabetic activity of VHAs is tested using the α-amylase inhibition method. Results and Discussion: The designed VHAs were successfully synthesized, well characterized by necessary spectroscopic techniques (1H and 13C NMR), Electrospray Ionization Mass and the structure of the VHAs was very clearly interpreted and discussed. The chemical structure and electronic topographies of VHAs agree with the biological activity distinctions. Hence, thorough analysis has been achieved in the computational methods such as Frontier molecular orbitals, molecular electrostatic potential and Mulliken charge distribution studies using the density functional theory method. The correlation between in vitro studies and docking results revealed that structural and electronic properties production an important role in biological activity. Conclusions: The VHAs obtainable very well α-amylase inhibitory activity and comparable results were obtained in the molecular docking studies. [ABSTRACT FROM AUTHOR]

To obtain more sustainable and active food packaging materials, PHBV films containing 5% wt. of phenolic compounds with different molecular structures (ferulic acid, vanillin, and catechin) and proved antioxidant and antimicrobial properties were obtained by melt blending and compression molding. These were characterized by their structural, mechanical, barrier, and optical properties, as well as the polymer crystallization, thermal stability, and component migration in different food simulants. Phenolic compounds were homogenously integrated within the polymer matrix, affecting the film properties differently. Ferulic acid, and mainly catechin, had an anti-plasticizing effect (increasing the polymer glass transition temperature), decreasing the film extensibility and the resistance to breaking, with slight changes in the elastic modulus. In contrast, vanillin provoked a plasticizing effect, decreasing the elastic modulus without notable changes in the film extensibility while increasing the water vapor permeability. All phenolic compounds, mainly catechin, improved the oxygen barrier capacity of PHBV films and interfered with the polymer crystallization, reducing the melting point and crystallinity degree. The thermal stability of the material was little affected by the incorporation of phenols. The migration of passive components of the different PHBV films was lower than the overall migration limit in every simulant. Phenolic compounds were released to a different extent depending on their thermo-sensitivity, which affected their final content in the film, their bonding forces in the polymer matrix, and the simulant polarity. Their effective release in real foods will determine their active action for food preservation. Catechin was the best preserved, while ferulic acid was the most released. [ABSTRACT FROM AUTHOR]

Vanillin is one of the world's most important flavor and fragrance compounds used in foods and cosmetics. In plants, vanillin is reportedly biosynthesized from ferulic acid via the hydratase/lyase-type enzyme VpVAN. However, in biotechnological and biocatalytic applications, the use of VpVAN limits the production of vanillin. Although microbial enzymes are helpful as substitutes for plant enzymes, synthesizing vanillin from ferulic acid in one step using microbial enzymes remains a challenge. Here, we developed a single enzyme that catalyzes vanillin production from ferulic acid in a coenzyme-independent manner via the rational design of a microbial dioxygenase in the carotenoid cleavage oxygenase family using computational simulations. This enzyme acquired catalytic activity toward ferulic acid by introducing mutations into the active center to increase its affinity for ferulic acid. We found that the single enzyme can catalyze not only the production of vanillin from ferulic acid but also the synthesis of other aldehydes from p-coumaric acid, sinapinic acid, and coniferyl alcohol. These results indicate that the approach used in this study can greatly expand the range of substrates available for the dioxygenase family of enzymes. The engineered enzyme enables efficient production of vanillin and other value-added aldehydes from renewable lignin-derived compounds. [ABSTRACT FROM AUTHOR]

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In the last decade, "expressions" of grape marc spirits aged in wooden barrels of characteristic amber color and complex sensory attributes have been introduced. Yet studies on constituents migrating from the barrel to the beverage are scarce, and their metabolic profile remains unexplored. Furthermore, the literature on the assessment of their antioxidant activity is limited. NMR metabolomics and spectrophotometry have been implemented in 38 samples to elucidate the impact of the aging procedure on the metabolites' composition and establish whether these beverages exhibit antioxidant activity. Provenance was related to fusel alcohols, esters, acetaldehyde, methanol, saccharides, and 2-phenylethanol, while ethyl acetate and ethyl lactate contributed to discriminating samples of the same winery. Identified metabolites such as vanillin, syringaldehyde, and sinapaldehyde were related to the aging procedure. The maturation in the barrel was also associated with an increase in xylose, glucose, fructose, and arabinose. The antioxidant potential of the aged Greek grape marc spirits resulting from their maturation in oak barrels was highlighted. The metabolic profiling and antioxidant potential of aged Greek grape marc spirits were assessed for the first time. Finally, the enrichment of the aromatic region was noted with the presence of metabolites with a furanic and phenolic ring derived, respectively, from the polysaccharides' degradation or the thermal decomposition of lignin. [ABSTRACT FROM AUTHOR]

In this study, the separation of lignin from a mild alkaline sugarcane bagasse extract was studied, and the impacts of different parameters on the filtration performance were evaluated. The tested parameters included transmembrane pressure (0.5–3.0 bar), shear rates (2831–22,696 s−1), temperature (20 and 40 °C), membrane molecular weight cut-off (5 and 10 kDa), and membrane material (polyethersulfone and polysulfone). During the filtration process, the permeate flux and all the main components of the extract were analyzed, including lignins (acid insoluble lignin and acid soluble lignin), sugars (xylose, arabinose, glucose, and galactose), total phenolic compounds, and phenolic acids (p-coumaric acid, ferulic acid, vanillin, and 4-hydroxybenzaldehyde). It was proved that the tested conditions had a great impact on the permeate flux and molecule retention rate. Increasing the temperature from 20 to 40 °C resulted in a much higher permeate flux for the 5 kDa PES membrane, and the impact of shear rate was greater at 40 °C for this membrane. Although the 5 kDa PES membrane could retain slightly more large molecules, i.e., acid-insoluble lignin and xylose, the 10 kDa membrane afforded greater phenolic acid removal capacity, leading to higher purity. For the 10 kDa PS membrane, the polarization layer began to form at TMP below 0.5 bar. This membrane had a lower retention rate for all molecules than the 10 kDa PES membrane. [ABSTRACT FROM AUTHOR]

This review article summarized our identification of the most active principles that show prominent anti-tumor, antiviral and anti-UVC activity from the natural resources. 3-Styrylchromone derivatives showed outstanding tumor-specific cytotoxicity against human oral squamous cell carcinoma cell lines. The target molecule was estimated to be estrogen-related receptorα. Various lignified materials showed the highest anti-HIV activity by rapid inactivation of the virus. Lignin degradation products, such as phenylpropanoids and vanillin, exhibited potent anti-UVC activity, their activity surpassing that of vitamin C, due to their higher stability. These compounds can be applicable as new protective substances against cancer, virus and radiation. [ABSTRACT FROM AUTHOR]

In present times, vanillin stands out as a promising therapeutic molecule that can be implicated in the treatment of neurodegenerative disorders (NDs), notably Alzheimer's disease (AD). This can be attributed to the highly potent scavenging activity of vanillin against reactive oxygen species (ROS). Oxidative stress leads to generation of ROS that serves a critical role in AD's pathological progression. It is apparent from various studies that diets rich in polyphenols prevent oxidative stress associated with AD development, implying the crucial role of vanillin in AD therapeutics. It is crucial to maintain iron balance to manage AD associated oxidative stress, unveiling the significance of human transferrin (hTf) that maintains iron homeostasis. Here, we have performed an integrated study of spectroscopic and computational approaches to get insight into the binding mechanism of vanillin with hTf. In the preliminary study, molecular docking deciphered that vanillin primarily occupies the hTf binding pocket, forming multiple interactions with its key residues. Moreover, the binding mechanism was evaluated at an atomistic level employing comprehensive molecular dynamic (MD) simulation. MD analysis demonstrated that binding of vanillin to hTf stabilizes its structure, without inducing any significant alterations in its native conformation. The docked complex was maintained throughout the simulations without changing its original conformation. Essential dynamics analysis further confirms that hTf achieved a stable conformation with vanillin. The outcomes were further supplemented by fluorescence spectroscopy which confirms the formation of stable hTf-vanillin complex. Taken together, the current study unveils the interaction mechanism of vanillin with hTf and providing a platform to use vanillin in AD therapeutics in the context of iron homeostasis. [ABSTRACT FROM AUTHOR]

The electrification of the production of fine chemicals has received increased interest in combating petrochemical routes with a high carbon footprint. Oxidising biomass from waste streams with concomitant hydrogen production, such as the transformation of lignin to vanillin, would be a great asset. Here, we show the combination of activity screening using a scanning droplet cell on a thin‐film Ni−Fe library and performance testing in a flow‐through cell with pulse electrolysis. The identified optimal Ni−Fe material composition was prepared on Ni foam with a polymer/metal precursor spray method. Full factorial and Doehlert matrix designs were employed to better comprehend each parameter's effects on the complex system. The best conditions for the electrooxidation of Kraft lignin at room temperature were at E1st=1.36 V vs RHE, t1st=1 s for the first pulse and E2nd=1.60 V vs RHE and t2nd=15 s for the second pulse, leading to the significantly improved production of 2.15 μmols of vanillin at room temperature. Pulsed chronopotentiometry was demonstrated to be a cost‐effective and robust technique with a simple setup for the valorisation of Kraft lignin. Combined with a subsequent thermolysis step, 8.05 μmols of vanillin were obtained. [ABSTRACT FROM AUTHOR]

Vanillin is a valuable natural product that can be used as a fragrance and additive. Recent research in the biosynthesis of vanillin has brought attention to a key enzyme, carboxylic acid reductase (CAR), which catalyzes the reduction of vanillic acid to vanillin. Nevertheless, the biosynthesis of vanillin is hampered by the low activity and stability of CAR. As such, a rational design campaign was conducted on a well-documented carboxylic acid reductase from Segniliparus rugosus (SrCAR), using vanillic acid as the model substrate. After combined active site saturation and iterative site-specific mutagenesis, the best quadruple mutant N292H/K524S/A627L/E1121W (M3) was successfully obtained. In comparison to the wildtype SrCAR, M3 demonstrated a 4.2-fold increase in catalytic efficiency (k cat / K m), and its half-life (t 1/2) was enhanced by 3.8 times up to 385.08 minutes at 40 °C. In silico docking and molecular dynamics simulation provided insights into the improved activity and stability. In the subsequent preparative-scale reaction with 100 mM (16.8 g L−1) vanillic acid, the whole cell catalysis utilizing M3 produced 10.15 g·L−1 of vanillin and 1.11 g·L−1 of vanillyl alcohol, respectively. This work demonstrates a dual improvement in the activity and thermal stability of SrCAR, thereby potentially facilitating the application of carboxylic acid reductase in the biosynthesis of vanillin. • Carboxylic acid reductases (CARs) can reduce acids to aldehyde under mild reaction conditions. • Engineering of the catalytic activity and thermostability of CAR via rational design. • A 4.2-fold increase in k cat / K m was achieved, with the t 1/2 was enhanced by 3.8 times up to 385.08 mins at 40 °C. • Insight into the source of enhanced performance was gained by molecular dynamics simulations. [ABSTRACT FROM AUTHOR]

Perovskite based on Sn have attracted extensive attention to address the toxicity challenge associated with Pb‐based perovskite solar cells. However, Sn‐based perovskite solar cells（SPSCs）are notable for their poor stability and loss of efficiency due to rapid oxidation of Sn2+ to Sn4+ in air. To slow down the rapid oxidation, a number of antioxidants are suggested. Nevertheless, the antioxidant normally gets oxidized to non‐antioxidizing by‐products in a single‐stage redox reaction and loses the function of oxidation prevention. Herein, vanillin is introduced, a natural antioxidant with a double‐staged redox reaction to inhibit the oxidation of Sn2+ or reduce Sn4+ back to Sn2+, which improves the efficiency and prolongs the open‐air stability of SPSCs. With 7.5% vanillin doping, an outstanding efficiency of 13.18% is achieved. Moreover, exposure of the solar cell to 160 W microwave irradiation for 3 minutes resulted in significant efficiency recovery from 88% to 96.5% at 812 hours and from 35.7% to 65.4% after 2200 hours of aging. This work reveals the potential of natural antioxidation and short microwave irradiation as suitable approaches to elevate the efficiency and lifetime of SPSCs. [ABSTRACT FROM AUTHOR]

The targeted catalytic transfer hydrodeoxygenation (CTHDO) of vanillin (VAN) to 2‐methoxy‐4‐methylphenol (MMP) holds promise as a noteworthy subject in the domain of bio‐oil utilization, offering potential as a future biofuel and finding versatile use in fragrances and pharmaceutical industry. In this study, stable, cost‐effective Ni nanoparticles supported on montmorillonite (MMT) clay was synthesized for eco‐friendly, alcohol‐mediated CTHDO of VAN to MMP. The Ni(10 %)/MMT catalyst achieved >99 % VAN conversion and 95.2 % MMP selectivity using isopropanol (IPA) as a solvent and hydrogen donor. Characterization encompassing PXRD, SEM, TEM, and XPS confirmed successful Ni integration onto MMT. NH3‐TPD, pyridine‐IR, and H2‐TPR analysis evaluated catalyst surface acidity and reducibility. The synergy between surface‐modulated acidity of MMT and Ni nanoparticles collectively facilitated IPA and VAN activation, driving CTHDO performance. The Ni(10 %)/MMT catalyst displayed sustained activity over five recycles. Its exceptional stability and performance underscore its potential as an eco‐friendly, sustainable, non‐noble transition metal‐based catalyst for the hydrogenating lignin bio‐oil model compounds, contributing to greener catalytic advancements. [ABSTRACT FROM AUTHOR]

This work is focused on performing a quantitative assessment of the environmental impacts associated with an organic synthesis reaction, optimized using an experimental design approach. A nucleophilic substitution reaction was selected, employing vanillin as the substrate, a phenolic compound widely used in the food industry and of pharmaceutical interest, considering its antioxidant and antitumoral potential. To carry out the reaction, three different solvents have been chosen, namely acetonitrile (ACN), acetone (Ace), and dimethylformamide (DMF). The syntheses were planned with the aid of a multivariate experimental design to estimate the best reaction conditions, which simultaneously allow a high product yield and a reduced environmental impact as computed by Life Cycle Assessment (LCA) methodology. The experimental results highlighted that the reactions carried out in DMF resulted in higher yields with respect to ACN and Ace; these reactions were also the ones with lower environmental impacts. The multilinear regression models allowed us to identify the optimal experimental conditions able to guarantee the highest reaction yields and lowest environmental impacts for the studied reaction. The identified optimal experimental conditions were also validated by experimentally conducting the reaction in those conditions, which indeed led to the highest yield (i.e., 93%) and the lowest environmental impacts among the performed experiments. This work proposes, for the first time, an integrated approach of DoE and LCA applied to an organic reaction with the aim of considering both conventional metrics, such as reaction yield, and unconventional ones, such as environmental impacts, during its lab-scale optimization. [ABSTRACT FROM AUTHOR]

The solubility of two natural phenolic compounds (vanillic acid (VA) and vanillin (V)) in four individual solvents (ethanol, butan-2-ol, ethylene glycol, and ethyl acetate) was measured using the gravimetric method from 283.15 to 323.15 K at atmospheric pressure. The optimization of the complexes between VA--solvents and V--solvents using the B3LYP theoretic technique and the 6-31+G (d, p) basis set indicated that the absolute value of interaction energy was higher, suggesting that the interaction between solute and the solvent was stronger. In addition, two excellent activity coefficient models (NRTL and Wilson) were used to correlate and evaluate the equilibrium solubility results. The highest relative average deviation and root-mean-square deviation values for VA are 4.36% and 3.09 x 10-3, respectively, and 3.35% and 5.52 x 10-3 for V. Furthermore, the excess enthalpy of the solution was determined on the basis of thermodynamic relations and the Wilson model. The findings indicate that the dissolution process was endothermic. [ABSTRACT FROM AUTHOR]

Background: Vanillin is a flavoring substance derived from vanilla. We are currently developing a biotransformation method for vanillin production using glucose. This report describes the last step in vanillin production: the conversion of vanillic acid to vanillin. First, we selected Corynebacterium glutamicum as the host owing to its high vanillin resistance. The aromatic aldehyde reductase gene (NCgl0324) and vanillic acid demethylase protein subunits A and B gene (vanAB, NCgl2300-NCgl2301) were deleted in C. glutamicum genome to avoid vanillin degradation. Next, we searched for an aromatic carboxylic acid reductase (ACAR), which converts vanillic acid to vanillin. Seventeen ACAR homologs from various organisms were introduced into C. glutamicum. Results: In vivo conversion experiments showed that eight ACARs were successfully expressed and produced vanillin. In terms of conversion activity and substrate specificity, the ACARs from Gordonia effusa, Coccomyxa subellipsoidea, and Novosphingobium malaysiense are promising candidates for commercial production. Conclusions: Corynebacterium glutamicum harboring Gordonia effusa ACAR produced 22 g/L vanillin, which is, to the best of our knowledge, the highest accumulation reported in the literature. At the same time, we discovered ACAR from Novosphingobium malaysiense and Coccomyxa subellipsoidea C-169 with high substrate specificity. These findings are useful for reducing the byproducts. [ABSTRACT FROM AUTHOR]

The chemoselective hydrodeoxygenation of natural lignocellulosic materials plays a crucial role in converting biomass into value‐added chemicals. Yet their complex molecular structures often require multiple active sites synergy for effective activation and achieving high chemoselectivity. Herein, it is reported that a high‐entropy alloy (HEA) on high‐entropy oxide (HEO) hetero‐structured catalyst for highly active, chemoselective, and robust vanillin hydrodeoxygenation. The heterogenous HEA/HEO catalysts were prepared by thermal reduction of senary HEOs (NiZnCuFeAlZrOx), where exsolvable metals (e.g., Ni, Zn, Cu) in situ emerged and formed randomly dispersed HEA nanoparticles anchoring on the HEO matrix. This catalyst exhibits excellent catalytic performance: 100% conversion of vanillin and 95% selectivity toward high‐value 2‐methyl‐4 methoxy phenol at low temperature of 120 °C, which were attributed to the synergistic effect among HEO matrix (with abundant oxygen vacancies), anchored HEA nanoparticles (having excellent hydrogenolysis capability), and their intimate hetero‐interfaces (showing strong electron transferring effect). Therefore, our work reported the successful construction of HEA/HEO heterogeneous catalysts and their superior multifunctionality in biomass conversion, which could shed light on catalyst design for many important reactions that are complex and require multifunctional active sites. [ABSTRACT FROM AUTHOR]