Search Results (72)

Aroma is an important indicator for evaluating the quality of baijiu. In this study, we determined the aroma-active compounds in four representative brands of strong-aroma baijiu from Sichuan and Jianghuai regions through GC-MS/O, and GC-TOF-MS quantification. In addition, the non-volatile composition of four baijiu samples was quantified by BSTFA derivatization and GC-MS. By constructing a full recombination model containing both volatile and non-volatile components, the effect of different groups of non-volatile compounds on the aroma of strong-aroma baijiu was evaluated through recombination-omission tests. A total of 72 aroma-active compounds and 59 non-volatile compounds were identified and quantified. The results indicated that pyrazines, furfural, and furan derivatives displayed higher aroma intensities in strong-aroma baijiu produced in Sichuan compared to that produced in Jianghuai. The recombination model that included both aroma-active and non-volatile compounds showed a closer resemblance to the original baijiu samples, underscoring the critical role these compounds play in shaping the dominant aroma profile of strong-aroma baijiu. Non-volatile compounds significantly influenced six aroma attributes: fruity, sweet, sauce, pit, acidic, and alcoholic notes. Omission tests revealed that among posorly volatile organic acids, monobasic acids had distinct effects on the aroma profile, while dibasic acids did not show any noticeable influence on the sensory characteristics. Full article

In the chemistry of bio-based furans, the Diels–Alder reaction plays an important role as a renewable route for the synthesis of fuels, fine chemicals, and monomers. Nonetheless, the unfavorable kinetic and thermodynamic parameters inherent to the Diels–Alder reaction involving furans as dienes often lead to the reversibility of cycloaddition, resulting in decreased equilibrium conversion and diastereoselectivity. In this study, we present a new strategy for overcoming the problem of reversibility in chemical reactions. We demonstrate that conducting the reaction under solvent-free conditions can facilitate the transition from a molten state formed by the initial reactants to a solid phase containing the reaction product along with an excess of the initial substrate. According to our results, such a liquid-to-solid transition of the reaction mixture can lead to exceptionally high conversion and diastereoselectivity in the furan–maleimide Diels–Alder reaction, particularly for challenging electron-poor furanic substrates. Our approach enables the reversible furan–maleimide Diels–Alder reaction to be performed in a cleaner and more environmentally friendly manner, free from the complexities associated with the use of solvents and the need for purification from side products. Full article

Ascorbic acid (ASC) is a furan-based lactone derived from 2-ketogluconic acid that functions as a major antioxidant and redox buffer in mature plant tissues, although its content is lower in meristematic cells. ASC is commonly considered a reactive oxygen species (ROS) scavenger; however, its role in the regulation of plant development remains unclear. Additionally, the chemical behavior of ascorbate warrants special attention during ASC supplementation in in vitro plant culture. In this study, I investigated in detail the behavior of ascorbate in plant tissue culture medium and its uptake by plants. As a secondary objective, the role of ascorbate in root growth regulation was evaluated. The effects of low ASC levels on root architecture and its interaction with auxin signaling were studied using the vtc1 and vtc2 mutants of Arabidopsis thaliana, as well as through external ascorbate supplementation. Several marker lines for auxin response/distribution were used, along with direct ascorbate measurement via HPLC. Reducing ascorbate content through mutations had no significant effect on root development or auxin signaling, whereas high-concentration ASC supplementation inhibited both auxin signaling and root development, as demonstrated using auxin response and transport markers. At the organ level, ASC supplementation significantly downregulated auxin response-mediated cell cycle activation during lateral root induction. Based on the data presented, exogenous ascorbate may regulate root development through its interaction with auxin signaling pathways. Full article

Biomass, as a renewable carbon resource, holds broad application prospects. Among various bio-based platform molecules, furan derivatives play a significant role in green chemical production. Notably, the conversion of 2-methylfuran (2-MF) to 3-acetyl-1-propanol (3-AP) over bifunctional catalysts has attracted considerable interest. In this study, a Pd@PHZSM-5 catalyst was prepared by encapsulating Pd nanoparticles within P-doped HZSM-5 for 2-MF conversion. The encapsulation improved Pd dispersion and metal–acid synergy, enhancing both catalytic activity and 3-AP selectivity. Additionally, phosphorus doping increased HZSM-5 crystallinity, resulting in excellent stability. This work provides a feasible strategy for optimizing metal–acid cooperation, offering theoretical guidance for bifunctional catalysis and biomass valorization. Full article

With the advancement of new synthetic techniques, 5-Methyl-2-ethylfuran (5-MEF) has emerged as a promising renewable biofuel. In this study, the potential energy surfaces for the unimolecular dissociation reaction, H-addition reaction, and H-abstraction reaction of 5-MEF were mapped at the CBS-QB3 level. The temperature- and pressure-dependent rate constants for these reactions on the potential energy surfaces were determined by solving the master equation, using both transition state theory and Rice–Ramsperger–Kassel–Marcus theory. The results showed that the dissociation reaction of the C(6) site on the branched chain of 5-MEF has the largest rate constant and is the main decomposition pathway, while the dissociation reaction of the H atom on the furan ring has a lower rate constant and is not the main reaction pathway. In addition, the dissociation of H atoms on the branched chain and intramolecular H-transfer reactions also have high-rate constants and play an important role in the decomposition of 5-MEF. H-addition reactions mainly occur at the C(2) and C(5) sites, and the generation of the corresponding products through β-breakage becomes the main reaction pathway. With the increase in temperature, the H-addition reaction at the C(2) site gradually changes to a substitution reaction, dominating the formation of C₂H₅ and 2-methylfuran. Full article

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common form of chronic liver disease, for which only resmetirom has recently received FDA approval. Prevention is crucial, as it can help manage and potentially reverse the progression of MAFLD to more severe stages. Omega-3 fatty acids, which are a type of polyunsaturated fatty acid (PUFA), have numerous beneficial effects in health and disease, including liver disease. Other bioactive lipids, such as furanic fatty acids (FuFA) and hydroxy fatty acid esters (FAHFA), have also demonstrated several benefits on relevant markers of liver dysfunction in animal and cell models. However, the effects of FAHFAs on hepatic steatosis are inconsistent, and studies on the impact of FuFAs in MAFLD are scarce. Further and more extensive research is required to better understand their role in liver health. The aim of this narrative review is to provide a brief overview of the potential effects of omega-3 fatty acids and other bioactive lipids, such as FuFAs and FAHFAs, on liver disease, with a focus on MAFLD. Full article

The effects of furfural and 5-methyl-2-furfural produced by the Maillard reaction on PhIP formation were investigated in chemical models and roasted pork patties. In the chemical models, the results indicated that increasing levels of furfural (r = −0.7338, R² = 0.9557) and 5-methyl-2-furfural (r = −0.7959, R² = 0.9864) significantly reduced PhIP formation, displaying a strong linear correlation. The effects of furfural and 5-methyl-2-furfural on the precursors of phenylalanine (Phe) and phenylacetaldehyde showed a significant reduction in the Phe level, while the level of phenylacetaldehyde was not increased. In addition, neither furfural nor 5-methyl-2-furfural could significantly reduce creatinine or PhIP. Further mechanism studies showed that furfural (5-methyl-2-furfural) directly captured Phe to form the corresponding Schiff base compounds a (2-((furan-2-ylmethylene) amino)-3-phenylpropanoic acid) and b (2-(((5-methylfuran-2-yl)methylene)amino)-3-phenylpropanoic acid). This process reduced the production of phenylacetaldehyde, thereby inhibiting the PhIP formation pathway. More importantly, these two compounds were detected in roasted pork patties to which glucose was added. The above pathway was finally confirmed in roasted pork patties. These results revealed that furfural and 5-methyl-2-furfural, formed during the Maillard reaction, play a significant role in inhibiting the formation of PhIP by reacting with Phe. Full article

In this study, a simple one-step blend of isolated soy protein and sucrose was used directly as a wood adhesive for plywood manufacturing. The bonding performance, water resistance, curing performance, and thermal stability of the adhesive were evaluated. The preparation process of the plywood was optimized and the curing mechanism was also investigated. The results demonstrate the following: (1) Sucrose was successfully converted into furan compounds, especially 5-hydroxymethylfurfural (5-HMF), which underwent a sufficient cross-linking reaction with the SPI, and this was the key during the curing of the adhesive. (2) The effect of hot-pressing temperature on the bonding performances was the most significant and played a key role in the success of the test, followed by hot-pressing time, solid content, and adhesive loading. (3) In this study, 200 °C was the critical point at which the adhesive obtained good wet bonding strength and was also the critical temperature at which the effective conversion of sucrose into 5-HMF occurred. (4) The optimum preparation parameters of plywood were a hot-pressing temperature of 216 °C, a hot-pressing time of 1 min/mm, a solid content of 50%, and adhesive consumption of 220 g/m². Using this process, a bonding strength in warm water of 1.74 MPa, a bonding strength in boiling water of 1.50 MPa, and a wood failure rate of more than 80% were obtained for the plywood. Full article

The development of anticancer drugs is costly and time intensive. Computational approaches optimize the process by studying molecules such as naphthoquinones. This research explores the quantitative structure–activity relationship (QSPR) and molecular interactions among 2,2-dimethyl-3-((3-nitrophenyl)amino)-2,3-dihydronaphtho[1,2-b]furan-4,5-dione (QPhNO₂), a Nor-β-Lapachone derivative with anticancer properties, and the following polymers for nanoencapsulation: polymethyl methacrylate (PMMA), polycaprolactone (PCL), and poly-lactic-co-glycolic acid (PLGA). Spartan 14 optimized the compounds using density functional theory (DFT), while ArgusLab performed docking, and Discovery Studio analyzed post-docking results. Simulations indicated that polymers with larger energy gaps are more stable and less prone to deformation than QPhNO₂, facilitating interaction with polymer chains. The binding energies for PMMA/QPhNO₂, PCL/QPhNO₂, and PLGA/QPhNO₂ interactions were −4.607, −4.437, and −1.814 kcal/mol, respectively. Docking analysis revealed non-bonded interactions between polymers and QPhNO₂. These findings highlight the role of computational methods in nanoencapsulation and molecular characterization, guiding the development of future analogs and combinations. Full article

This study aims to reveal the evolution mechanism of odour and taste active compounds in cooked marinated pork knuckles via typical process steps; among them, the brine soup stage was the most important part due to spices’ enriching flavours. These results revealed that the content and diversity of volatile compounds increased due to the addition of spices and heating temperature, imparting a unique aroma. Aldehydes played the main role in the overall odour. Benzaldehyde, hexanal, 1-octen-3-ol, levulinic acid, hydroxyacetone, ethyl octanoate, and 2-pentyl-furan were identified as the most important odour-active compounds. The key taste-active amino acids were glutamine, leucine, valine, and lysine. The IMP, AMP, and GMP provided a strong umami taste. Taste nucleotides and Val, Leu, Ile, and Phe were important precursor substances for aldehydes. The high responses of the electronic nose indicated that the gas component contained alkanes, alcohols, and aldehydes. The synergistic effects between umami-free amino acids and nucleotides correlated well with umami, as assessed by the electronic tongue. These results could be a starting point for the manufacturing industry, contributing to a better understanding of product performance. Full article

Garcinia gummi-gutta, commonly known as Garcinia cambogia (syn.), is a popular traditional herbal medicine known for its role in treating obesity, and has been incorporated into several nutraceuticals globally for this purpose. The fruit rind is also used as a food preservative and a condiment because of its high content of hydroxycitric acid, which imparts a sharp, sour flavour. This review highlights the major bioactive compounds present in the tree Garcinia gummi-gutta, with particular emphasis on (2S, 3S)-tetrahydro-3-hydroxy-5-oxo-2,3-furan dicarboxylic acid, commonly referred to as garcinia acid. This acid can be isolated in large amounts through a simple procedure. Additionally, it explores the synthetic transformations of garcinia acid into biologically potent and functionally useful enantiopure compounds, a relatively under-documented area in the literature. This acid, with its six-carbon skeleton, a γ-butyrolactone moiety, and two chiral centres bearing chemically amenable functional groups, offers a versatile framework as a chiron for the construction of diverse molecules of both natural and synthetic origin. The synthesis of chiral 3-substituted and 3,4-disubstituted pyrrolidine-2,5-diones, analogues of the Quararibea metabolite—a chiral enolic-γ-lactone; the concave bislactone skeletons of fungal metabolites (+)-avenaciolide and (−)-canadensolide; the structural skeletons of the furo[2,3-b]furanol part of the anti-HIV drug Darunavir; (−)-tetrahydropyrrolo[2,1-a]isoquinolinones, an analogue of (−)-crispine A; (−)-hexahydroindolizino[8,7-b]indolones, an analogue of the naturally occurring (−)-harmicine; and furo[2,3-b]pyrroles are presented here. Full article

Electron-rich heteroaromatics, such as furan, thiophene and pyrrole, as well as their benzo-condensed derivatives, are of great interest as components of natural products and as starting substances for various products including high-tech materials. Although their reactions with Brønsted and Lewis acids play important roles, in particular as the primary step of various transformations, they are often disregarded and mechanistically not understood. The present publication gives a first overview about this chemistry focusing on the parent compounds. It comprises reactions with strong Brønsted acids forming adducts that can undergo intramolecular proton and/or substituent transfer reactions, ring openings or ring transformations into other heterocycles, depending on their structure. Interactions with weak Brønsted acids usually initiate oligomerizations/polymerizations. A similar behaviour is observed in reactions of these heteroaromatics with Lewis acids. Special effects are achieved when the Lewis acids are activated through primary protonation. Deuterated Brønsted acids allow straight forward deuteration of electron-rich heteroaromatics. Mercury salts as extremely weak Lewis acids cause direct metalation in a straight forward way replacing ring H-atoms yielding organomercury heterocycles. This review will provide comprehensive information about the chemistry of adducts of such heterocycles with Brønsted and Lewis acids enabling chemists to understand the mechanisms and the potential of this field and to apply the findings in future syntheses. Full article

This study explored the potential of a series of PZM21 analogues for pain treatment. Specifically, the hydroxyphenyl ring of PZM21 was replaced with a naphthyl ring, the thienyl ring was substituted with either a phenyl ring or furan rings, and the essential dimethylamine and urea groups were retained. These compounds aimed to enhance safety and minimize the adverse effects associated with opioid drugs. The research findings suggest that compound 6a does not induce β-arrestin recruitment at low-nanomolar concentrations but exhibits significant analgesic effects in established mouse models. Compared to morphine, 6a shows advantages in alleviating respiratory depression and minimizing physical dependence. Molecular docking studies underscore the pivotal role of the D147 amino acid residue in the analgesic mechanism of 6a. Consequently, 6a is a compelling candidate for the development of safer opioid analgesics and warrants further attention. Full article

Inflammation serves as a pivotal defense mechanism orchestrated by the innate immune system to safeguard cellular health against adversities. Nonetheless, dysregulated inflammatory responses can precipitate chronic inflammatory ailments, notably autoimmune disorders. Central to this process are various pathways, with studies highlighting the pivotal role of transcription factors within the nuclear factor-kappa B (NF-κB) signaling pathway in disease onset and progression. This study concentrates on the p50 homodimer protein, a key transcription factor pivotal for the expression of proinflammatory cytokine genes. To explore potential inhibitors of p50, we conducted in silico procedures to investigate fifty-eight unexplored compounds, derived from plants indigenous to the Philippines. Initial screenings for compound feasibility, through drug-likeness analyses, yielded positive outcomes for 34 compounds. Subsequent docking analyses revealed six compounds exhibiting binding energies (ranging from −3.7 to −4.2 kcal/mol) akin to or lower than the positive control, dexamethasone (−3.7 kcal/mol). These compounds include eudesm-11-en-4α-O-β-D-3-tigoyloxy-6-deoxy-glucopyranoside, wadeiol, grandiflorolide, eudesm-11-en-4α-O-β-D-3-senecioyloxy-6-deoxyglucopyranoside, α-pinene-7β-O-β-D-2- acetylglucopyranoside, and (2aβ,3α,5aβ,6β,7α,8aα)-6-[2-(3-furanyl)ethyl]-2a,3,4,5,5a,6,7,8,8a,8b- decahydro-2a,3-dihydroxy-6,7,8b-trimethyl-2H-naphtho[1-8-bc]furan-2-one. Interaction analyses revealed a common engagement of amino acid residues within the p50 DNA binding pocket, notably Arg57, Tyr60, Glu63, Lys244, Ala245, Pro246, Lys275, Arg308, Gln309, and Phe310, through hydrogen bonding, van der Waals forces, alkyl, and pi–alkyl interactions. Pharmacophore analysis underscored aromatic rings, hydroxyl, methyl, and methylene groups as pivotal for non-covalent interactions with p50. Additionally, root mean square fluctuation (RMSF) analysis demonstrated minimal residue fluctuations in p50 upon ligand binding compared to the ligand-free protein structure. In conclusion, the six shortlisted compounds exhibiting comparable binding affinities with dexamethasone hold promise as potential anti-inflammatory agents targeting the NF-κB p50 homodimer. Full article

Reaction mixtures of naturally abundant aldoses and CH nucleophiles allow for the formation of functionalized furan precursors using low temperatures and metal-free catalysis in aqueous solutions of dilute base catalysts. We employ in situ NMR assays to clarify the mechanism and kinetics of the conversion. Catalysis serves a double role in ring-opening of stable aldoses such as glucose and xylose and facilitating the subsequent reactions with CH acids such as malononitrile or cyanoacetamide. Resultant acyclic products are shown to convert quickly to a monocyclic product prior to the slower formation of a more stable bicyclic intermediate and dehydration to tri-functionalized furan. Especially the reversible 5-exo-dig ring closure entailing oxygen attack onto a nitrile carbon is surprisingly fast with an equilibrium vastly towards the cyclic state, sequestering reactive groups and allowing the selective conversion to tri-functionalized furan. The reaction hinges on the fast formation of intermediates without CH acidity and competes with the oligomerization of CH nucleophiles. Insight derived from in situ NMR analysis shows the prowess of high-resolution in situ spectroscopy in clarifying the interplay between catalysts and reactants. Such insight will be vital for the optimization of reactions that upgrade biorenewables under benign conditions. Full article