Aromatic Research Articles

Design of experiments method into upgrading pyrolytic oil for sustainable aviation fuel additives by hydrotreating and hydrocracking.

Recycling waste to produce liquid fuels for the automotive and aviation industries is a major global concern, especially in light of the ongoing energy crisis. Because waste is used in thermal conversion processes, the resulting liquid products often require additional processing to reduce their density and viscosity, and to remove oxygenated compounds or pollutants that hinder further utilization. Catalytic hydrogenolytic reactions such as hydrodeoxygenation (HDO) and hydrocracking (HC) have been extensively applied to upgrade pyrolysis oils. Selecting the appropriate catalyst and optimizing the process operating conditions are crucial for yielding high-quality fuel. Design of experiments (DOE) and analysis of variance (ANOVA) can identify the primary factors of the process and their possible interactions. This research focuses on the conversion of pyrolysis oil derived from car tires into jet fuel and aims to determine the optimal HDO and HC conditions to maximize the concentration of the kerosene fraction. Hydrodeoxygenation and hydrocracking reactions using NiMo/γ-Al2O3 catalysts are examined under varying temperature, pressure, and time conditions. The compositions of the raw tire pyrolysis oil (TPO) are mainly characterized by heteroatom content, aromatic compounds, olefins and acetylenes, alkanes, and cycloalkanes, which play key roles during HDO and HC procedures. Subsequently, the distillation and separation of the fuel fractions are carried out to determine the quality of the product.

Improved biosynthesis of tyrosol by epigenetic modification-based regulation and metabolic engineering in Saccharomyces cerevisiae.

Aromatic amino acids and their derivatives are high value chemicals widely used in food, pharmaceutical and feed industries. Current preparation methods for aromatic amino acid products are fraught with limitations. In this study, the efficient biosynthesis of aromatic amino acid compound tyrosol was investigated by epigenetic modification-based regulation and optimization of the biosynthetic pathway of aromatic amino acids. The production of tyrosol was significantly improved by the overexpression of m6A modification writer Ime4 and reader Pho92, and the positive regulator Gcr2. Introduction of Bbxfpk and deletion of Gpp1 further improved tyrosol production. Then the feedback inhibition of the shikimate pathway was relieved by the mutants Aro4K229L and Aro7G141S. The final tyrosol producing engineered strain was constructed by the deletion of PHA2, replacement of the native promoter of ARO10 with the strong promoter PGK1p, and introduction of tyrosine decarboxylase PcAAS. In the background of m6A modification regulation, this strain ultimately produced 954.69 ± 43.72 mg/L of tyrosol, promoted by 61.7-fold in shake-flask fermentation.

Sensory chemistry of Spirulina: Unveiling trends and innovations in aromatic volatile organic compound biosynthesis in off-flavors and odor mitigation strategies

Sensory chemistry of Spirulina: Unveiling trends and innovations in aromatic volatile organic compound biosynthesis in off-flavors and odor mitigation strategies

Low-Transition Temperature Mixtures Pretreatment and Hydrothermal Carbonization of Corncob Residues for CO2 Capture Materials

Activated char is one of the most cost-effective absorbents for low-temperature CO2 capture. Rather than disposing of corncob residues by open-air burning, this study focused on improving corncob residues through pretreatment with low-transition temperature mixtures (LTTM) of choline chloride and glycerol combined with hydrothermal carbonization before being converted to CO2 capture activated char. Compared to raw corncob residues, cellulose-rich materials (CRMs) from the pretreatment had less thermal stability and substantial changes in cellulose crystallinity and surface functional groups relative to cellulose and lignin, thus differently resulting in surface morphologies of activated biochars and hydrochars. The crystallinity of cellulose was still maintained in CRMs but not when the CRMs were hydrothermally carbonized. All hydrochars mainly contained aromatic compounds of lignin. The presence of choline chloride in LTTM pretreatment caused activated hydrochar to increase the specific surface area (from 25.4 to 64.0 m2/g) while reducing the total pore volume (from 1.2 to 0.7 m3/g) and pore size (from 184.3 to 34.3 nm). The activated CRM hydrochar had a CO2 adsorption capacity of over ten times that of the activated biochar (no pretreatment and hydrothermal carbonization were applied). After 20 cycles of regeneration, it maintained >97% of the initial CO2 adsorption capacity. This finding pointed out that pretreatment and hydrothermal carbonization can potentially enhance the CO2 adsorption performance of activated hydrochar from corncob residues.

Biochemical, micro and ultrastructural changes in vanilla pods (Vanilla planifolia, Andrews) during the curing process

Vanilla is used in several industries, due to during the artisanal curing process, compounds responsible for a highly demanded aroma are synthesized. This process involves physical, biochemical, microbiological and structural changes, which through their study with high-resolution techniques allowed for deep introspection at the ultra-structural level, to identify cellular structures. Which, under conditions leading to the pod during the process, allow the synthesis, release, and storage of molecules aroma responsible. The integration of the referred changes will allow the strategies generation that lead to better use of the vanilla extract and its residue obtained after the extraction processes (∼95%) to which the sheath could be subjected. The proximal chemical analysis showed an increase in lipids (∼25%) at 10 SS (drying-sweating cycles) associated with oleoresins and aroma responsible compounds. Proteins increased (∼50%), a result of the catalytic activity of the enzymes present and associated with the endophytic flora. β-glucosidase associated with the synthesis of aromatic compounds, increased their activity at 10 SS (196 IU/mL). The mesocarp showed a folding and shrinkage of (∼50%), evaluated by SEM and image analysis. Using CLSM, the major compounds in the bean were located and their relationship with the micro and ultra-structure. Using TEM, plastoglobules responsible for the odorant compounds accumulation and plasmodesmata for their transport and storage were identified. The comprehensive study of the curing process and the phenomena conjunction involved, allowed the process key stage identification, important for the proposal of strategies that lead to the optimal use of the metabolites and their residues.

Polycyclic Aromatic Compounds in Ambient PM2.5 in the Central Region of Ghana: Molecular Distribution, Origin and Cancer Risk Assessment

The distribution, sources and the cancer risk of human exposure to PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) were investigated in this work. Airborne particulate samples were obtained at the Winneba highway junction (WHJ) and Apam fish-smoking community (AFC) in the Central Region of Ghana from July 2022 to June 2023. PM2.5 particulates were collected using a Gent sampler equipped with a Gast pump and a stacked filter unit. 24-hour sampling was done two times a month using Teflon filters. Dichloromethane and gas chromatography with a mass spectrometer (GC-MS) were used to extract and analyse the samples, respectively, to identify 14 PAH compounds. The study discovered average PAH concentrations of 67.38 ng/m3 at WHJ and 41.59 ng/m3 at AFC. PAH profile was predominated with Phenanthrene, accounting for 25-27 % of total PAHs. The distribution pattern of PAHs was LMW>HMW>MMW at the two research sites. A strong correlation was found among BaA, BkF, BbF and BeP. The diagnostic ratio model revealed that PAHs stemmed from pyrogenic sources. The carcinogenic PAHs (BaP, BaA, Chr, BbF, BkF, BghiP) contributed approximately 90 % to the carcinogenic activity of total PAHs, denoting a high cancer potential of PAHs. The mean levels of BaP were about 8-10 times higher than the permissible limit of 1 ng/m3. The overall cancer risk values for exposure to PAHs via inhalation were more than 10-4, signifying high cancer risks: 11.61×10-4-21.14×10-4 for children and 19.91×10-4-36.24×10-4 for adults. Reducing PM2.5 and its health effects requires the use of clean fuel and the adoption of eco-friendly transportation.

Z-scheme H5PMo10V2O40/g-C3N4 heterojunction with strong photooxidative capacity for promoting efficient cleavage of Cα-Cβ bond in lignin models and lignin.

The efficient photocatalytic breakage of Cα-Cβ bonds has great significance for the valorization of lignin into value-added aromatic chemicals, but remains challenging owing to their demanding depolymerization conditions and high bond dissociation energies. In this study, the Z-scheme heterojunction H5PMo10V2O40/g-C3N4 (HPA/CN) photocatalyst was elaborately developed for the selective and efficient cleaving of Cα-Cβ bonds in real lignin and its β-O-4 models under mild conditions. The construction of Z-scheme heterojunction with irregular sheet micromorphology not only enhanced the charge separation and redox abilities, but also broadened the light absorption range and promoted charge-to-surface transfer in two redox components. Notably, 35% HPA/CN could completely convert the 2-phenoxy-1-phenylethanol with Cα-Cβ bond cleavage selectivity of 97.4%, achieving approximately 50.0- and 2.2-times higher conversion rates compared to HPA and CN, respectively. Meanwhile, this strategy also offered a wide substrate scope containing various β-O-4 model compounds and native lignin, leading to the generation of corresponding aromatics. The mechanism experiments revealed that photoinduced holes and superoxide radicals synergistically triggered the oxidative cleavage of Cα-Cβ bond. This study could provide a reference for photocatalytic production of value-added aromatic monomers by exploiting both renewable feedstocks and solar energy.

Progress in Double Dearomatization Reactions.

Dearomatization reactions are among the most straightforward and efficient methods for creating sp3-rich cyclic systems from simple, readily available arenes. These reactions have been widely applied in the total synthesis of natural products, medicinal chemistry, and material sciences. The fruitful development of dearomatization strategies and methodologies targeting single aromatic substrate over the past decades has paved the way for more sophisticated multiple dearomatization processes, which offer greater advantages in constructing molecular complexity. Double dearomatization reactions have made significant pioneering strides in recent years. This review will provide an overview of the strategies and detailed examples of multiple dearomatization reactions involving various aromatic compounds, along with a discussion of the related mechanisms and the major challenges that remain in this intriguing yet formidable field.

Iron(II/III) Alters the Relative Roles of the Microbial Byproduct and Humic Acid during Chromium(VI) Reduction and Fixation by Soil-Dissolved Organic Matter.

Though reduction of hexavalent chromium (Cr(VI)) to Cr(III) by dissolved organic matter (DOM) is critical for the remediation of polluted soils, the effects of DOM chemodiversity and underlying mechanisms are not fully elucidated yet. Here, Cr(VI) reduction and immobilization mediated by microbial byproduct (MBP)- and humic acid (HA)-like components in (hot) water-soluble organic matter (WSOM), (H)WSOM, from four soil samples in tropical and subtropical regions of China were investigated. It demonstrates that Cr(VI) reduction capacity decreases in the order WSOM > HWSOM and MBP-enriched DOM > HA-enriched DOM due to the higher contents of low molecular weight saturated compounds and CHO molecules in the former. The presence of Fe(II/III) selectively coprecipitates with high molecular weight components (e.g., tannins, lignin, and CHON-rich compounds) to form ferrihydrite and greatly inhibits Cr(VI) transformation and fixation in MBP-enriched DOM but enhances that in HA-enriched DOM. This is probably owing to the combined effects of (1) the increase of DOM electron-donating capacity and Fe(II) generation during the reactions of HA with Fe(II) and Fe(III), respectively; (2) the enrichment of phenolic and carboxyl groups, aromatic compounds, and carbon defects on ferrihydrite surfaces; and (3) the acceleration of HA decomposition and MBP mineralization by hydroxyl radicals. These findings enhance our understanding of the chemodiversity of soil DOM, the complex interactions between Cr(VI), DOM, and Fe(II/III), and can help design remediation strategies for contaminated environments.

Alterations in Protein Phosphorylation and Arginine Biosynthesis Metabolism Confer β-Phenylethanol Tolerance in Saccharomyces cerevisiae.

The aromatic compound β-phenylethanol (2-PE) is inherently toxic and can inhibit cell activity in Saccharomyces cerevisiae, making it highly challenging to enhance strain tolerance through rational design due to the lack of reliable connections between tolerance phenotype and genetic loci. This study employed adaptive laboratory evolution strategy to investigate the tolerance characteristics of S. cerevisiae S288C under inhibitory concentrations of 2-PE. The tolerant mutant SEC4.0 was characterized through comprehensive analysis of whole genome sequence, transcriptome, and phosphoproteome. The findings revealed that the high resistance of SEC4.0 was not primarily due to large-scale transcriptional upregulation of stress response genes, but rather through alterations in the phosphorylation levels of lipid-related pathways. PKC1 mutations that affect stress signal transduction and SPT3 mutations that affect arginine biosynthesis have been shown to significantly enhance 2-PE resistance. This study also investigated the effects of exogenous amino acid addition and synergistic effects with two key mutanted genes on 2-PE resistance. This study provides a foundation for enhancing yeast tolerance to this aromatic compound through rational design strategies.

Non-Substituted Aromatic Pyridine N-Oxide Additives with an Intrinsic N →O Acceptor for Ultra-Long-Life Zn||MnO2 Batteries.

Various organic and inorganic reagents containing N/O functional groups have been developed as additives to aqueous electrolytes (e.g., ZnSO4, ZS) of zinc-ion batteries (ZIBs). However, finding an additive that can significantly enhance the durability of Zn anodes by inhibiting Zn dendrites and side reactions remains a considerable challenge. Herein, pyridine N-oxides (PNO), a non-substituted aromatic compound with a nitrogen positive charge-induced N→O bond, are explored as ZS additives for highly durable Zn plating/stripping electrolytes (i.e., PNO/ZS). The optimized PNO0.03/ZS mixture demonstrates exceptional stability for Zn anodes, achieving a cycle life exceeding 4200 h and a Coulombic efficiency of 99.9% at 1 mA cm-2 and 1 mAh cm-2. It maintains over 1000 h of life and a cumulative capacity of 2.5 Ah cm-2, even when subjected to plating/stripping conditions intensified by a factor of 5. Importantly, it enables Zn||α-MnO2 cells to sustain high-current charge/discharge cycles for over 5000 cycles, retaining 80% (~125 mAh g-1) of the initial capacity, which is the best performance reported for similar additive systems. This exceptional stability is ascribed to the highly reversible Zn anode plating/stripping, facilitated by the suitable coordination interactions between the N→O acceptor of PNO and the Zn2+/H2O donor, effectively inhibiting side reactions.

Borylative desymmetrization of multifunctional haloarenes assisted by sodium dispersion.

Multiply halogenated aromatic compounds were selectively borylated by a boron alkoxide in the presence of sodium dispersion when the reaction was carried out at a low temperature, while multi-functionalization took place at an elevated temperature. The reaction of 1,4-dichlorobenzene with sodium dispersion (200-1200 mol%) in the presence of isopropyloxyboron pinacolate (120-240 mol%) afforded (4-chlorophenyl)boron pinacolate in up to 84% yield. Formation of diborylated product hardly accompanied under the reaction conditions at -78 °C for 1 h.

Tolerance to NSAIDs in Actinobacteria From a Mexican Volcano Crater: Genomics and Bioremediation Potential.

Non-steroidal anti-inflammatory drugs (NSAIDs) are emerging contaminants that pose significant health and environmental risks due to their persistence, including their presence in drinking water. Bioremediation, particularly through microorganisms such as actinobacteria, offers a sustainable approach to mitigate these pollutants. Actinobacteria from poly-extreme environments exhibit unique genetic and metabolic adaptations, enabling resistance to and degradation of various contaminants. This study aimed to evaluate the tolerance of actinobacteria to NSAIDs and conduct a genomic analysis of a selected strain. Actinobacteria were isolated from the crater of the Chichonal volcano [Chiapas, Mexico), resulting in 16 isolates. Among these, Micrococcus luteus P8SUE1, Micrococcus yunnanensis P9AGU1, and Kocuria rhizophila P1AGU3 demonstrated tolerance to diclofenac, ibuprofen, and paracetamol at concentrations of 1 ppm, 10 ppm, and 100 ppm, respectively. Whole-genome sequencing of M. yunnanensis P9AGU1 identified genes linked to the degradation of aromatic compounds and adaptations to extreme environmental conditions, highlighting its potential for bioremediation applications.

Aromatic ring compounds with different conjugation degrees in a boronic acid matrix to realize multicolor phosphorescence for time division colorful multiplexing.

Long lifetime multicolor phosphorescence materials possess excellent optical properties and have important application prospects in the fields of advanced anti-counterfeiting and information encryption. However, realizing long lifetime and color-tunable room temperature phosphorescent (RTP) carbon dot (CD) materials has proved challenging. In this study, the organic precursor molecules 2-phenethylamine (2-Ph), 9-aminophenanthrene (9-Ph) and 1-aminopyrene (1-Py) with different degrees of conjugation were selected to synthesize RTP CD composites: 2-Ph@BA, 9-Ph@BA and 1-Py@BA were synthesized by mixing with a boric acid (BA) matrix under high temperature pyrolysis. During high temperature pyrolysis, CDs form effective covalent and hydrogen bonds with the BA matrix to promote RTP activity and obtain a stable triplet state, which suppresses nonradiative transitions and leads to long lifetime RTP. Besides, as the conjugation of the organic precursor molecules 2-Ph, 9-Ph and 1-Py gradually increases, it results in a gradual decrease of the triplet state energy T1. Thus, 2-Ph@BA, 9-Ph@BA and 1-Py@BA RTP emission showed a significant redshift, leading to green, yellow and red phosphorescence colors, respectively. Finally, RTP CD composites are used in information security and time division colorful multiplexing based on the synthesized samples with different phosphorescence colors and lifetimes.

Exploration of alcohol dehydrogenase EutG from Bacillus tropicus as an eco-friendly approach for the degradation of polycyclic aromatic compounds

Polycyclic aromatic compounds (PACs) are pervasive environmental contaminants derived from diverse sources including pyrogenic (e.g., combustion processes), petrogenic (e.g., crude oil), and biological origins. They are commonly found in gasoline, coal, and crude oil, reflecting their prevalence and varied origins in natural and anthropogenic activities. The aim of this study is to use Bacillus tropicus which is a spore-forming, gram-positive and facultative anaerobic bacteria, containing a gene for PACs degradtion. In this study bacterial sample was collected from women’s vaginal discharge through streaking and spreading techniques. The DNA was extracted from bacterial culture and then the bacterium was identified through 16S rRNA which appeared to be B.tropicus. Then the computational analysis was conducted where the sequence similarity and functional analysis of alcohol dehydrogenase EutG protein from B.tropicus was analyzed through PSI-BLAT and SMART tool, respectively. The PSI-BLAST showed 100% query coverage score and 9 domains of alcohol dehydrogenase EutG protein were predicted through SMART tool. The quality of the protein was also assessed through ProQ server with a predicted LQ score of 8.091, a Maxsub score of − 0.350 and a z score of − 10.76. Then the phylogentic analysis was conducted to know the evolutionary relationship and closely related taxa. The 3D structure of the protein was predicted through SWISS MODEL and its quality was predicted through ERRAT with overall qauality factor of 98.708. The Ramachandran plot also predicted its quality and showed that 93.8% residues were in the most favored region. After this, 3D stucture of PACs were obtained from PubChem and molecular docking of the protein was performed with each of the compound. The lowest energy of − 10.3 was obtained with Indeno[1,2,3-cd] pyrene and the best docked complex was visulaized through discover studio to analyze its binding residues. Lastly, in-silico site-directed mutagenesis studies were performed which showed that the EutG gene (codes for alcoholic dehydrogenase) obtained from B. tropicus, will not get altered or have any decreasing effect on the enzyme’s stability if it goes through any mutations. This suggests that B. tropicus can act as an efficient, non-virulent, and reliable candidate for the eco-friendly and cost-effective bioremediation of PACs.

Enhancement of secondary ion yield on gas cluster ion beam-secondary ion mass spectrometry with nonaromatic matrices: Dependence on matrix species and molecular weight

The Ar gas cluster ion beam (Ar-GCIB) technique is advantageous for soft sputtering of large organic molecules. However, in secondary ion mass spectrometry (SIMS) measurements using Ar-GCIB, the secondary ion yield is typically very low. Matrix-enhanced (ME)-SIMS is a technique that has the potential to enhance the yield. In a previous study on ME-SIMS, aromatic compounds that are typically employed for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) were used for the matrix. Although aromatic rings are involved in soft ionization by absorption of energy from the laser probe in MALDI-MS, aromatic rings may not be required for ME-SIMS, which does not use a laser probe. In this study, the effect of non-aromatic matrices was investigated. The results indicated that some nonaromatic compounds are effective for enhancing sensitivity and that the degree of enhancement depends on the molecular weight of analytes. To investigate the reason for this, it was assumed that the yield in SIMS measurements is simply determined by the sputtering yield, the survival rate, and the ionization probability, each of which has molecular weight dependence. Under these assumptions, the SIMS yield is found to be dependent on the matrix species.

Growth and Study of L-Tyrosine Based Single Crystal for Photonic Applications: A Review

In the recent days the amino acid plays a vital role in the manufacturing of opto-electronic devices. The no essential amino acid named as L-Tyrosine (C9H11NO3) used in the growth of non-linear single crystal. A single crystal of L-Tyrosine doped with either phenolic compound or aromatic compound will be grown at constant atmospheric temperature using slow solvent evaporation technique. The addition of either phenolic compound or aromatic compound replaces hydroxyl element from tyrosine which changes the physical and chemical properties for NLO and optical applications. Key Words: Tyrosine, L-Tyrosine, Amino acids, Photonics NLO

Type III porous ionic liquids via lipophilicity differences for enhanced oxidation catalysis

AbstractIn this study, an innovative strategy is proposed to design porous ionic liquids (PILs) using lipophilicity differences, defined as type III‐B PIL, which overcomes the traditional size‐effect limitations in PIL design. An SBA‐15 confined high‐entropy single‐atom catalyst (HESAC@SBA‐15) with an oleophobic internal surface was engineered as the porous framework and oleaginous 1‐butyl‐3‐methylimidazolium tetrafluoroborate as the organic guest for constructing a novel type PIL (PILS‐B). This type of PILS‐B combines the exceptional gas storage capacity of PILs with the high catalytic activity of HESAC@SBA‐15. Additionally, the mesoporous structure of SBA‐15 enhances mass transfer during reactions, thereby improving catalytic efficiency. Using the aerobic oxidation of aromatic sulfur compounds in fuel oils as a model reaction, PILS‐B achieved a desulfurization efficiency of >99%. This strategy expands the variety of porous frameworks and organic guests for PIL design, showcasing the potential of PILs as effective and stable catalysts with broader applications in catalysis.

Innovative Production of 3D-Printed Ceramic Monolithic Catalysts for Oxidation of VOCs by Using Fused Filament Fabrication

In this work, ceramic monolithic catalyst carriers based on zirconium dioxide (ZrO2) were produced using fused filament fabrication (FFF). The active catalyst components were deposited on the resulting carriers using the wet impregnation method. The activity of the prepared monolithic catalysts was evaluated by catalytic oxidation of a mixture of aromatic volatile organic compounds: benzene, toluene, ethylbenzene, and o-xylene (BTEX). The efficiency of the prepared monolithic catalysts was investigated as a function of the geometry of the monolithic carrier (ZDP, Z, and M) and the chemical composition of the catalytically active component (MnFeOx, MnCuOx, and MnNiOx) during the catalytic oxidation of BTEX compounds. The mechanical stability of the catalyst layer and the dimensional stability of the 3D-printed monolithic catalyst carriers were investigated prior to the kinetic measurements. In addition, thorough characterization of the commercial ZrO2-based filament was carried out. The results of the efficiency of the prepared monolithic catalysts for the catalytic oxidation of BTEX showed that the 3D-printed model M, which contained MnFeOx as the catalytically active component, was the most successful catalyst for the oxidation of BTEX compounds. The mentioned catalyst enables the catalytic oxidation of all components of the BTEX mixture (>99% efficiency) at a temperature of 177 °C.

Laccase Functional Analysis: Substrates, Activity Assays, Challenges, and Prospects.

Enzyme functional analysis is a multifaceted process that can be used for various purposes, such as screening for specific activities, as well as developing, optimising, and validating processes or final products. Functional analysis methods are crucial for assessing enzyme performance and catalytic properties. Laccase, a well-known blue multi-copper oxidase, holds immense potential in diverse industries such as pharmaceuticals, paper and pulp, food and beverages, textiles, and biorefineries due to its clean oxidation process and versatility in handling a wide range of substrates. Despite its prominence, the use of laccase encounters challenges in selecting appropriate functional analysis substrates and methods. This review delves into the substrates utilised in qualitative and quantitative techniques for laccase activity analysis. Although laccase catalyses mono-electron oxidation of aromatic hydroxyl, amine, and thiol compounds efficiently, using molecular oxygen as an electron acceptor, the review identifies limitations in the specificity of the commonly employed substrates, concerns regarding the stability of certain compounds and highlights potential strategies.