The antisickling agent, 5-hydroxymethyl-2-furfural: Other potential pharmacological applications.

For the last two decades, the aromatic aldehyde 5-hydroxymethyl-furfural (5-HMF) has been the subject of several investigations for its pharmacologic potential. In 2004, the Safo group reported that 5-HMF has potent antisickling activity by targeting and ameliorating the primary pathophysiology of hypoxia-induced sickling of erythrocytes (red blood cells [RBC]). Following the encouraging outcome of the preclinical and phase I/II clinical studies of 5-HMF for the treatment of sickle cell disease (SCD), there have been multiple studies suggesting 5-HMF has several other biological or pharmacologic activities, including anti-allergic, antioxidant, anti-hypoxic, anti-ischemic, cognitive improvement, anti-tyrosinase, anti-proliferation, cytoprotective, and anti-inflammatory activities. The wide range of its effects makes 5-HMF a potential candidate for treating a variety of diseases including cognitive disorders, gout, allergic disorders, anemia, hypoxia, cancers, ischemia, hemorrhagic shock, liver fibrosis, and oxidative injury. Several of these therapeutic claims are currently under investigation and, while promising, vary in terms of the strength of their evidence. This review presents the research regarding the therapeutic potential of 5-HMF in addition to its sources, physicochemical properties, safety, absorption, distribution, metabolism, and excretion (ADME) profiles.

Unraveling the Electrocatalytic Activity in HMF Oxidation to FDCA by Fine-Tuning the Degree of NiOOH Phase Over Ni Nanoparticles Supported on Graphene Oxide.

The development of an efficient electrocatalyst for HMF oxidation to FDCA has been in the early stages. Herein, the NiNPs/GO-Ni-foam is fabricated as an electrocatalyst for FDCA production. However, the electrocatalytic performance of the untreated NiNPs/GO-Ni-foam is observed with moderate Faradaic efficiency (FE) (73.0%) and FDCA yield (80.2%). By electrochemically treating the NiNPs/GO-Ni-foam in an alkaline solution with positive potential at different treatment durations, the degree of NiOOH on metal surfaces is changed. The distinctive electrocatalytic activity obtained when using the different NiOOH degrees allows to understand the crucial impact of NiOOH species in HMF electrooxidation. Enhancing the portion of the NiOOH phase on the electrocatalyst surface improves electrocatalytic activity in terms of FE and FDCA yield up to 94.8±4.8% and 86.9±4.1%, respectively. Interestingly, as long as the NiOOH portion on the electrocatalyst surface is preserved or regenerated, the electrocatalyst performance can be intact even after several catalytic cycles. The theoretical study via density functional theory (DFT) also agrees with the experimental observations and confirms that the NiOOH phase facilitates the electrochemical transformation of HMF to FDCA through the HMFCA pathway, and the potential limiting step of the overall reaction is the oxidation of FFCA to FDCA.

Engineering 5-hydroxymethylfurfural (HMF) oxidation in Pseudomonas boosts tolerance and accelerates 2,5-furandicarboxylic acid (FDCA) production.

Due to its tolerance properties, Pseudomonas has gained particular interest as host for oxidative upgrading of the toxic aldehyde 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA), a promising biobased alternative to terephthalate in polyesters. However, until now, the native enzymes responsible for aldehyde oxidation are unknown. Here, we report the identification of the primary HMF-converting enzymes of P. taiwanensis VLB120 and P. putida KT2440 by extended gene deletions. The key players in HMF oxidation are a molybdenum-dependent periplasmic oxidoreductase and a cytoplasmic dehydrogenase. Deletion of the corresponding genes almost completely abolished HMF oxidation, leading instead to aldehyde reduction. In this context, two HMF-reducing dehydrogenases were also revealed. These discoveries enabled enhancement of Pseudomonas' furanic aldehyde oxidation machinery by genomic overexpression of the respective genes. The resulting BOX strains (Boosted OXidation) represent superior hosts for biotechnological synthesis of FDCA from HMF. The increased oxidation rates provide greatly elevated HMF tolerance, thus tackling one of the major drawbacks of whole-cell catalysis with this aldehyde. Furthermore, the ROX (Reduced OXidation) and ROAR (Reduced Oxidation And Reduction) deletion mutants offer a solid foundation for future development of Pseudomonads as biotechnological chassis notably for scenarios where rapid HMF conversion is undesirable.

Novel insights into the effects of 5-hydroxymethfurural on genomic instability and phenotypic evolution using a yeast model.

5-Hydroxymethfurural (5-HMF) is naturally found in a variety of foods and beverages and represents a main inhibitor in the lignocellulosic hydrolysates used for fermentation. This study investigated the impact of 5-HMF on the genomic stability and phenotypic plasticity of the yeast Saccharomyces cerevisiae. Using next-generation sequencing technology, we examined the genomic alterations of diploid S. cerevisiae isolates that were subcultured on a medium containing 1.2 g/L 5-HMF. We found that in 5-HMF-treated cells, the rates of chromosome aneuploidy, large deletions/duplications, and loss of heterozygosity were elevated compared with that in untreated cells. 5-HMF exposure had a mild impact on the rate of point mutations but altered the mutation spectrum. Contrary to what was observed in untreated cells, more monosomy than trisomy occurred in 5-HMF-treated cells. The aneuploidy mutant with monosomic chromosome IX was more resistant to 5-HMF than the diploid parent strain because of the enhanced activity of alcohol dehydrogenase. Finally, we found that overexpression of ADH6 and ZWF1 effectively stabilized the yeast genome under 5-HMF stress. Our findings not only elucidated the global effect of 5-HMF on the genomic integrity of yeast but also provided novel insights into how chromosomal instability drives the environmental adaptability of eukaryotic cells.IMPORTANCESingle-cell microorganisms are exposed to a range of stressors in both natural and industrial settings. This study investigated the effects of 5-hydroxymethfurural (5-HMF), a major inhibitor found in baked foods and lignocellulosic hydrolysates, on the chromosomal instability of yeast. We examined the mechanisms leading to the distinct patterns of 5-HMF-induced genomic alterations and discovered that chromosomal loss, typically viewed as detrimental to cell growth under most conditions, can contribute to yeast tolerance to 5-HMF. Our results increased the understanding of how specific stressors stimulate genomic plasticity and environmental adaptation in yeast.

Expansion of Auxiliary Activity Family 5 sequence space via biochemical characterization of six new copper radical oxidases.

Bacterial and fungal copper radical oxidases (CROs) from Auxiliary Activity Family 5 (AA5) are implicated in morphogenesis and pathogenesis. The unique catalytic properties of CROs also make these enzymes attractive biocatalysts for the transformation of small molecules and biopolymers. Despite a recent increase in the number of characterized AA5 members, especially from subfamily 2 (AA5_2), the catalytic diversity of the family as a whole remains underexplored. In the present study, phylogenetic analysis guided the selection of six AA5_2 members from diverse fungi for recombinant expression in Komagataella pfaffii (syn. Pichia pastoris) and biochemical characterization in vitro. Five of the targets displayed predominant galactose 6-oxidase activity (EC 1.1.3.9), and one was a broad-specificity aryl alcohol oxidase (EC 1.1.3.7) with maximum activity on the platform chemical 5-hydroxymethyl furfural (EC 1.1.3.47). Sequence alignment comparing previously characterized AA5_2 members to those from this study indicated various amino acid substitutions at active site positions implicated in the modulation of specificity.IMPORTANCEEnzyme discovery and characterization underpin advances in microbial biology and the application of biocatalysts in industrial processes. On one hand, oxidative processes are central to fungal saprotrophy and pathogenesis. On the other hand, controlled oxidation of small molecules and (bio)polymers valorizes these compounds and introduces versatile functional groups for further modification. The biochemical characterization of six new copper radical oxidases further illuminates the catalytic diversity of these enzymes, which will inform future biological studies and biotechnological applications.

Immobilised Ruthenium Complexes for the Electrooxidation of 5-Hydroxymethylfurfural.

Abundantly available biomass-based platform chemicals, including 5-hydroxymethylfurfural (HMF), are essential stepping stones in steering the chemical industry away from fossil fuels. The efficient catalytic oxidation of HMF to its diacid derivative, 2,5-furandicarboxylic acid (FDCA), is a promising research area with potential applications in the polymer industry. Currently, the most encouraging approaches are based on solid-state catalysts and are often conducted in basic aqueous media, conditions where HMF oxidation competes with its decomposition. Efficient molecular catalysts are practically unknown for this reaction. In this study, we report on the synthesis and electrocatalysis of surface-bound molecular ruthenium complexes for the transformation of HMF to FDCA under acidic conditions. Catalyst immobilisation on mesoporous indium tin oxide electrodes is achieved through the incorporation of phosphonic acid anchoring groups. Screening experiments with HMF and further reaction intermediates revealed the catalytic route and bottlenecks in the catalytic synthesis of FDCA. Utilising these immobilised electrocatalysts, FDCA yields of up to 85 % and faradaic efficiencies of 91 % were achieved, without any indication of substrate decomposition. Surface analysis by X-ray photoelectron spectroscopy (XPS) post-electrocatalysis unveiled the desorption of the catalyst from the electrode surface as a limiting factor in terms of catalytic performance.

Molecular Insights of 5-Hydroxymethylfurfural in a Mixture of Ionic Liquids and Alkylated Phenolic Solvents.

This paper presents all-atom molecular dynamics to understand the separation behavior of 5-hydroxymethylfurfural (5-HMF) from 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]+[BF4]- using alkylated phenols as extractants. We have utilized four solvents such as  4-methyl phenol (4-MP), 4-ethyl phenol (4-EP), 4-propyl phenol (4-PP), and 4-butyl phenol (4-BP). We perform structural, dynamic, and rigorous thermodynamic analyses of 5-HMF in the mixture of ILs and solvents. The [BMIM]+[BF4]- show a strong interactions with phenols. The self-diffusion coefficient of 5-HMF shows a 3-fold increase with a decrease in the methyl group on the phenol. The solvation-free energy (DGsolv) of 5-HMF shows favorable in phenols. On the other hand, the transfer free energy (DGtransfer) of 5-HMF presents favorable from ILs to phenols. The partition coefficient (log P) values shows favorability for separation of 5-HMF using phenols. Overall, the molecular level analysis provides the role of the alkyl group effect on the phenols for extracting 5-HMF from the ILs.

Assessment of 5-Hydroxymethylfurfural in Food Matrix by an Innovative Spectrophotometric Assay.

Foods contaminants pose a challenge for food producers and consumers. Due to its spontaneous formation during heating and storage, hydroxymethylfurfural (HMF) is a prevalent contaminant in foods rich in carbohydrates and proteins. Colorimetric assays, such as the Seliwanoff test, offer a rapid and cost-effective method for HMF quantification but require careful optimization to ensure accuracy. We addressed potential interference in the Seliwanoff assay by systematically evaluating parameters like incubation time, temperature, and resorcinol or hydrochloric acid concentration, as well as the presence of interfering carbohydrates. Samples were analyzed using a UV-Vis spectrophotometer in scan mode, and data obtained were validated using HPLC, which also enabled quantification of unreacted HMF for assessing the protocol's accuracy. Incubation time and hydrochloric acid percentage positively influenced the colorimetric assay, while the opposite effect was observed with the increase in resorcinol concentration. Interference from carbohydrates was eliminated by reducing the acid content in the working reagent. HPLC analyses corroborated the spectrophotometer data and confirmed the efficacy of the proposed method. The average HMF content in balsamic vinegar samples was 1.97 ± 0.94 mg/mL. Spectrophotometric approaches demonstrated to efficiently determine HMF in complex food matrices. The HMF levels detected in balsamic vinegars significantly exceeded the maximum limits established for honey. This finding underscores the urgent need for regulations that restrict contaminant levels in various food products.

Au-Based Bimetallic Catalysts for Aerobic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid under Base-Free Reaction Conditions.

The aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) plays a pivotal role in the synthesis of renewable, biodegradable plastics and sustainable chemicals. Although supported gold nanoclusters (NCs) exhibit significant potential in this process, they often suffer from low selectivity. To address this challenge, a series of gold-M (M means Ni, Fe, Cu, and Pd) bimetallic NCs catalysts were designed and synthesized to facilitate the selective oxidation of HMF to FDCA. Our findings indicate that the introduction of doped metals, particularly Ni and Pd, not only improves the reaction rates for HMF tandem oxidation but also promotes high yields of FDCA. Various characterizations techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), in situ diffuse reflectance infrared Fourier transform spectroscopy of CO adsorption (CO-DRIFTS), and temperature-programmed desorption of oxygen (O2-TPD), were employed to scrutinize the structural and electronic properties of the prepared catalysts. Notably, an electronic effect was observed across the Au-based bimetallic catalysts, facilitating the activation of reactant molecules and enhancing the catalytic performance. This study provides valuable insights into the alloy effects, aiding in the development of highly efficient Au-based bimetallic catalysts for biomass conversions.

Base-Free Oxidation of HMF to FDCA over Ru/Cu-Co-O·MgO under Aqueous Conditions.

The copper-cobalt metal oxide composite magnesium oxide catalyst loaded with Ru has achieved the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to the bio-based polyester monomer 2,5-furandicarboxylic acid (FDCA) under base-free conditions. Several Ru/Cu-Co-O·MgO catalysts were prepared, with Cu-Co-O being a combination of CuO and Co3O4. The catalyst's activity was boosted by the synergistic interaction between copper and cobalt, as well as an optimal copper-to-cobalt molar ratio. Optimal catalytic activity was observed in the Ru4/Cu1-Co1-O·MgO catalyst, loaded with 4 wt% Ru when copper-to-cobalt molar ratio of 1:1 and magnesium oxide compounding amount of 6 mmol were employed. The inclusion of MgO and the load of Ru not only expanded the specific surface area of the catalyst but also heightened its basicity. Additionally, the presence of loaded Ru improved the catalyst's reducibility at low temperatures. In aqueous solution under oxygen pressure, the conversion rate of HMF achieved 100%, and the yield of FDCA was 86.1%. After five reaction cycles, examining the catalyst and solution revealed that Ru nanoparticles resisted leaching or oxidation, and MgO exhibited only slight dissolution. The green separation of the product was achieved using semi-preparative liquid chromatography, selectively collecting the FDCA-containing solution by exploiting variations in interactions between solutes and the stationary/mobile phases. The subsequent steps involved rotary evaporation and drying, resulting in FDCA powder with a purity exceeding 99%. Notably, this approach eliminated the need to introduce concentrated hydrochloric acid into the system for FDCA separation, providing a novel method for synthesising powdered FDCA.

Surfactant Directionally Assembled at the Electrode-Electrolyte Interface for Facilitating Electrocatalytic Aldehyde Hydrogenation.

Electrocatalytic hydrogenation of unsaturated aldehydes to unsaturated alcohols is a promising alternative to conventional thermal processes. Both the catalyst and electrolyte deeply impact the performance. Designing the electrode-electrolyte interface remains challenging due to its compositional and structural complexity. Here, we employ the electrocatalytic hydrogenation of 5-hydroxymethylfurfural (HMF) as a reaction model. The typical cationic surfactant, cetyltrimethylammonium bromide (CTAB), and its analogs are employed as electrolyte additives to tune the interfacial microenvironment, delivering high-efficiency hydrogenation of HMF and inhibition of the hydrogen evolution reaction (HER). The surfactants experience a conformational transformation from stochastic distribution to directional assembly under applied potential. This oriented arrangement hampers the transfer of water molecules to the interface and promotes the enrichment of reactants. In addition, near 100 % 2,5-bis(hydroxymethyl)furan (BHMF) selectivity is achieved, and the faradaic efficiency (FE) of the BHMF is improved from 61 % to 74 % at -100 mA cm-2. Notably, the microenvironmental modulation strategy applies to a range of electrocatalytic hydrogenation reactions involving aldehyde substrates. This work paves the way for engineering advanced electrode-electrolyte interfaces and boosting unsaturated alcohol electrosynthesis efficiency.

Ultra-Dense Supported Ruthenium Oxide Clusters via Directed Ion Exchange for Efficient Valorization of 5-Hydroxymethylfurfural.

Maximizing the loadings of active centers without aggregation for a supported catalyst is a grand challenge but essential for achieving high gravimetric catalytic activity, especially toward multi-step reactions. The oxidation of 5-hydroxymethylfurfural (HMF), a key biomass-derived platform molecule, into 2,5-furandicarboxylic acid (FDCA), a promising alternative to polyester monomer, is such a multi-step reaction that involves 6 proton and electron transfers. This process often demands strong alkaline environment but also suffers from the alkali-driven polymerization side-reaction. Meanwhile, neutral media ameliorates the polymerization, but lacks efficient catalyst toward deep oxidation. Herein, we devised a strategy of creating ultra-dense supported Ru oxide clusters via directed ion exchange in a Co hydroxyanion (CoHA) support material. Pyrimidine ligands were first incorporated into the CoHA interlayers, and the subsequent evacuation of pyrimidines created porous channels for the directed ion exchange with the built-in anions in CoHA, which allowed the dense and mono-disperse functionalization of RuCl6 2- anions and their resulting Ru oxide clusters. These ultra-dense Ru oxide clusters not only enable high HMF electrooxidation currents under neutral conditions but also create microscopic channels in-between the clusters for the expedited re-adsorption and oxidation of intermediates toward highly oxidized product, such as 5-formyl-2-furoic acid (FFCA) and FDCA. A two-stage HMF oxidation process, consisting of ambient conversion of HMF into FFCA and FFCA oxidation into FDCA under 60 °C, was eventually developed to first achieve a high FDCA yield of 92.1 % under neutral media with significantly reduced polymerization.

Different RONS Generation in MTC-SK and NSCL Cells Lead to Varying Antitumoral Effects of Alpha-Ketoglutarate + 5-HMF.

BACKGROUND: Carbonylated proteins (CPs) serve as specific indicators of increased reactive oxygen and nitrogen species (RONS) production in cancer cells, attributed to the dysregulated mitochondrial energy metabolism known as the Warburg effect. The aim of this study was to investigate the potential of alpha-ketoglutarate (aKG), 5-hydroxymethylfurfural (5-HMF), and their combination as mitochondrial-targeting antioxidants in MTC-SK or NCI-H23 cancer cells. METHODS: MTC-SK and NCI-H23 cells were cultured in the absence or presence of varying concentrations (0-500 µg/mL) of aKG, 5-HMF, and the combined aKG + 5-HMF solutions. After 0, 24, 48, and 72 h, mitochondrial activity, cancer cell membrane CP levels, cell growth, and caspase-3 activity were assessed in aliquots of MTC-SK and NCI-H23 cells. RESULTS: The mitochondrial activity of MTC-SK cells exhibited a concentration- and time-dependent reduction upon treatment with aKG, 5-HMF, or the combined aKG + 5-HMF. The half-maximal inhibitory concentration (IC50%) for mitochondrial activity was achieved at 500 µg/mL aKG, 200 µg/mL 5-HMF, and 200 µg/mL aKG + 66.7 µg/mL 5-HMF after 72 h. In contrast, NCI-H23 cells showed a minimal reduction (10%) in mitochondrial activity even at the highest combined concentration of aKG + 5-HMF. The CP levels in MTC-SK cells were measured at 8.7 nmol/mg protein, while NCI-H23 cells exhibited CP levels of 1.4 nmol/mg protein. The combination of aKG + 5-HMF led to a decrease in CP levels specifically in MTC-SK cells. The correlation between mitochondrial activity and CP levels in the presence of different concentrations of combined aKG + 5-HMF in MTC-SK cells demonstrated a linear and concentration-dependent decline in CP levels and mitochondrial activity. Conversely, the effect was less pronounced in NCI-H23 cells. Cell growth of MTC-CK cells was reduced to 60% after 48 h and maintained at 50% after 72 h incubation when treated with 500 µg/mL aKG (IC50%). Addition of 500 µg/mL 5-HMF inhibited cell growth completely regardless of the incubation time. The IC50% for 5-HMF on MTC-CK cell growth was calculated at 375 µg/mL after 24 h incubation and 200 µg/mL 5-HMF after 72 h. MTC-SK cells treated with 500 µg/mL aKG + 167 µg/mL 5-HMF showed no cell growth. The calculated IC50% for the combined substances was 250 µg/mL aKG + 83.3 µg/mL 5-HMF (48 h incubation) and 200 µg/mL aKG + 66.7 µg/mL 5-HMF (72 h incubation). None of the tested concentrations of aKG, 5-HMF, or the combined solution had any effect on NCI-H23 cell growth at any incubation time. Caspase-3 activity increased to 21% in MTC-CK cells in the presence of 500 µg/mL aKG, while an increase to 59.6% was observed using 500 µg/mL 5-HMF. The combination of 500 µg/mL aKG + 167.7 µg/mL 5-HMF resulted in a caspase-3 activity of 55.2%. No caspase-3 activation was observed in NCI-H23 cells when treated with aKG, 5-HMF, or the combined solutions. CONCLUSION: CPs may serve as potential markers for distinguishing between cancer cells regulated by RONS. The combination of aKG + 5-HMF showed induced cell death in high-RONS-generating cancer cells compared to low-RONS-generating cancer cells.

Comprehensive Study Addressing the Challenge of Efficient Electrocatalytic Biomass Upgrading of 5-(Hydroxymethyl)Furfural (HMF) with a CH3 NH2 Ionic Liquid on Metal-Embedded Mo2 B2 MBene Nanosheets.

Amine-containing derivatives are important intermediates in drug manufacturing; sustainable synthesis of amine compounds from green carbon-based biomass derivatives has attracted increasing attention, especially the reductive amination of biomass molecules via electrochemical upgrading. To achieve efficient reductive amination of 5-(hydroxymethyl)furfural (HMF) via electrocatalytic biomass upgrading, this work proposes a new HMF biomass upgrading strategy based on metal supported on Mo2 B2 MBene nanosheets using a density functional theory comprehensive study. HMF and methylamine (CH3 CH2 ) can be reduced to 5-(hydroxymethyl) aldiminefurfural (HMMAMF) via electrocatalytic biomass upgrading, which is identified as a promising technology to produce pharmaceutical intermediates. Based on the proposed reaction mechanisms of HMF reductive amination, this work performs a systematic study of HMF amination to HMMAMF using an atomic model simulation method. This study aims to design a high-efficiency catalyst based on Mo2 B2 @TM nanosheets via the reductive amination of 5-HMF and provide insights into the intrinsic relation between thermochemical and material electronic properties and the role of dopant metals. This work establishes the Gibbs free energy profiles of each reaction HMF Biomass Upgrading on Mo2 B2 systems and obtained the limiting potentials of the rate-determining step, which included the kinetic stability of dopants, HMF adsorbability, and the catalytic activity and selectivity of the hydrogen evolution reaction or surface oxidation. Furthermore, charge transfer, d-band center (εd ), and material property (φ) descriptors are applied to establish a linear correlation to determine promising candidate catalysts for reductive amination of HMF. The candidates Mo2 B2 @Cr, Mo2 B2 @Zr, Mo2 B2 @Nb, Mo2 B2 @Ru, Mo2 B2 @Rh, and Mo2 B2 @Os are suitable high-efficiency catalysts for HMF amination. This work may contribute to the experimental application of biomass upgrading catalysts for biomass energy and guide the future development of biomass conversion strategies and utilization.

5-Hydroxymethylfurfural multimers induce pseudo-allergic reaction through FcεRI at high doses.

Under acidic and high temperature conditions, 5-hydroxymethylfurfural (5-HMF) converted from sugar further produces dimers (Compound II) and trimers (Compound III). The polymers were less reported, and sensitization effect of them was reported in this study. Compounds II and III induced the local and systemic anaphylaxis effect in passive cutaneous anaphylaxis mice model and activated RBL-2H3 cell inducing [Ca2+ ] mobilization, resulting in the release of ß-hexosaminidase and histamine in vitro. The gene knockdown assay figured out that Compounds II and III induced degranulation through FcεRI. Further, Compounds II and III had a certain affinity with FcεRI by cell membrane chromatography and may combine on the "proline sandwich" structure indicated by molecular docking. All above suggested Compounds II and III can induce pseudo-allergic reaction through FcεRI in vivo and in vitro. Our work provides basic research to prove that the newly discovered 5-HMF transformants, Compounds II and III, induce pseudo-allergic reaction in vitro and in vivo through FcεRI, which is different pathway from 5-HMF. In foods with high sugar content, the sensitization of Compounds II and III needs more attention. In high-sugar foods and medicines, especially traditional Chinese medicine injections, the content of transformants needs to be detected.

Bio-Derived Furanic Compounds with Natural Metabolism: New Sustainable Possibilities for Selective Organic Synthesis.

Biomass-derived C6-furanic compounds have become the cornerstone of sustainable technologies. The key feature of this field of chemistry is the involvement of the natural process only in the first step, i.e., the production of biomass by photosynthesis. Biomass-to-HMF (5-hydroxymethylfurfural) conversion and further transformations are carried out externally with the involvement of processes with poor environmental factors (E-factors) and the generation of chemical wastes. Due to widespread interest, the chemical conversion of biomass to furanic platform chemicals and related transformations are thoroughly studied and well-reviewed in the current literature. In contrast, a novel opportunity is based on an alternative approach to consider the synthesis of C6-furanics inside living cells using natural metabolism, as well as further transformations to a variety of functionalized products. In the present article, we review naturally occurring substances containing C6-furanic cores and focus on the diversity of C6-furanic derivatives, occurrence, properties and synthesis. From the practical point of view, organic synthesis involving natural metabolism is advantageous in terms of sustainability (sunlight-driven as the only energy source) and green nature (no eco-persisted chemical wastes).

A Comprehensive Review on Metal Catalysts for the Production of Cyclopentanone Derivatives from Furfural and HMF.

The catalytic transformation of biomass-based furan compounds (furfural and HMF) for the synthesis of organic chemicals is one of the important ways to utilize renewable biomass resources. Among the numerous high-value products, cyclopentanone derivatives are a kind of valuable compound obtained by the hydrogenation rearrangement of furfural and HMF in the aqueous phase of metal-hydrogen catalysis. Following the vast application of cyclopentanone derivatives, this reaction has attracted wide attention since its discovery, and a large number of catalytic systems have been reported to be effective in this transformation. Among them, the design and synthesis of metal catalysts are at the core of the reaction. This review briefly introduces the application of cyclopentanone derivatives, the transformation mechanism, and the pathway of biomass-based furan compounds for the synthesis of cyclopentanone derivatives. The important progress of metal catalysts in the reaction since the first report in 2012 up to now is emphasized, the characteristics and catalytic performance of different metal catalysts are introduced, and the critical role of metal catalysts in the reaction is discussed. Finally, the future development of this transformation process was prospected.

Acrylamide and 5-Hydroxymethylfurfural in Synthetic Sugar Cane Syrup: Mitigation by Additives.

The ability of additives to reduce the formation of acrylamide in simulated sugar cane syrups was investigated. Organic acids, B vitamins, and inorganic salts were added individually and in combination to simulated thickened cane juice, and the mixtures were heated at 120 °C for 30 min. Calcium chloride (1%), citric acid (0.1%), and vitamin B3 (0.1%) were the most effective individual additives from each chemical family. The effects of CaCl2 (0-1%), citric acid (0-0.125%), and vitamin B3 (0-0.1125%), when added in combination, on the concentrations of acrylamide and hydroxymethylfurfural (HMF) were studied using a Box-Behnken design. Combinations of all three additives lowered the acrylamide production, but only the combination of citric acid and vitamin B3 had a significant synergistic effect. However, all these additives stimulated the production of HMF, and no significant interactive effect between pairs of additives on HMF production was observed. Calcium chloride stimulated the formation of HMF most strongly. These results indicate that certain combinations of these additives effectively reduce acrylamide formation, but they also lead to an increase in the formation of HMF in sugar syrup.

Formation of Maillard Reaction Products in Aged Sorghum Vinegar during Ageing and Protective Effects of Pure Vinegar Melanoidin Against CCl4-Induced Rat Hepatic Damage.

Research background: The processing method generally affects the toxicity and biological activity of aged sorghum vinegar. This study investigates the changes in the intermediate Maillard reaction products of sorghum vinegar during ageing and the in vivo hepatoprotective effects of pure melanoidin obtained from it. Experimental approach: High-performance liquid chromatography (HPLC) and fluorescence spectrophotometry were utilized to quantify intermediate Maillard reaction products. The CCl4-induced liver damage in rats was used to evaluate the protective role of pure melanoidin in rat liver. Results and conclusions: Compared with the initial concentration, the 18-month ageing process caused a 1.2- to 3.3-fold increase in the concentrations of intermediate Maillard reaction products, i.e. 5-hydroxymethylfurfural (HMF), 5-methylfurfural (MF), methyglyoxal (MGO), glyoxal (GO) and advanced glycation end products (AGEs). The concentrations of HMF in the aged sorghum vinegar were 6.1-fold higher than the 450 µM limit standard for honey, implying the need for shortening the ageing of the vinegar in practice for safety concerns. Pure melanoidin (Mr>3.5 kDa) demonstrated significant protective effects against CCl4-induced rat liver damage, as evidenced by normalized serum biochemical parameters (transaminases and total bilirubin), suppressing hepatic lipid peroxidation and reactive oxygen species, as well as increasing glutathione amount and restoring antioxidant enzyme activities. Histopathological analysis revealed that melanoidin in vinegar reduced cell infiltration and vacuolar hepatocyte necrosis in rat liver. The findings demonstrated that a shortened ageing process should be considered in practice to ensure the safety of aged sorghum vinegar. Vinegar melanoidin is a potential alternative for the prevention of hepatic oxidative damage. Novelty and scientific contribution: This study demonstrates that the manufacturing process had a profound influence on the generation of vinegar intermediate Maillard reaction products. In particular, it revealed the in vivo hepatoprotective effect of pure melanoidin from aged sorghum vinegar, and provides insight into the in vivo biological activity of melanoidin.

Increase in colour stability of pomegranate juice against 5-hydroxymethylfurfural (HMF) through copigmentation with phenolic acids.

BACKGROUND: Anthocyanins are responsible for both attractive colour of pomegranate juice (PJ) and its health-promoting effects against cancer and coronary heart disease. However, 5-hydroxymethylfurfural (HMF) at some concentrations causes anthocyanin degradation. The present study aimed to reduce the degradation of PJ anthocyanins as a result of HMF at various concentrations (0-20 mg L-1 ) through phenolic acid [PA; ferulic (FA), gallic (GA) and caffeic acids (CA)] copigmentation during storage at 20 °C. RESULTS: A strong correlation (r = 0.872) was found between anthocyanin degradation rate and HMF concentration in PJ without PA addition. An increase in HMF concentration during storage caused faster (< 32%) anthocyanin degradation. However, PA addition reduced (< 60 times) the HMF formation rate. The lowest HMF formation rates (0.07-0.28 day-1 ) were determined in PJ with added GA. Although GA caused an important increase in content of cyanidin-3-glucoside (16-42%), which is major PJ anthocyanin, against HMF at all concentrations, CA (15%) and FA (28%) increased cyanidin-3-glucoside content against 10 mg of HMF L-1 . FA maintained its protection effect against the highest HMF concentration (20 mg of HMF L-1 ), but CA lost its protection effect. Generally, FA increased stabilities of hyperchromic effect (HE) (9.6-27.7%) and colour density (CD) (57.1-74.3%) at all HMF concentrations, although CA increased HE stability (19.8-37.7%) in the presence of 10 and 20 mg of HMF L-1 . Interactions of 'all individual anthocyanins-FA' and 'delphinidin-based anthocyanins-GA/CA' resulted in copigmentation. CONCLUSION: FA addition was recommended to increase CD and HE for PJ containing HMF between 3.1-5.6 mg L-1 , whereas the addition of GA was recommended to increase anthocyanin stability for PJ containing 12.0 mg of HMF L-1 . © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.