Furfural Derivatives Research Articles

A new method for rapid determination of carbohydrate and total carbon concentrations using UV spectrophotometry

A new UV spectrophotometry based method for determining the concentration and carbon content of carbohydrate solution was developed. This method depends on the inherent UV absorption potential of hydrolysis byproducts of carbohydrates formed by reaction with concentrated sulfuric acid (furfural derivatives). The proposed method is a major improvement over the widely used Phenol–Sulfuric Acid method developed by DuBois, Gilles, Hamilton, Rebers, and Smith (1956). In the old method, furfural is allowed to develop color by reaction with phenol and its concentration is detected by visible light absorption. Here we present a method that eliminates the coloration step and avoids the health and environmental hazards associated with phenol use. In addition, avoidance of this step was shown to improve measurement accuracy while significantly reducing waiting time prior to light absorption reading. The carbohydrates for which concentrations and carbon content can be reliably estimated with this new rapid Sulfuric Acid–UV technique include: monosaccharides, disaccharides and polysaccharides with very high molecular weight.

ChemInform Abstract: Microwave Heating for Rapid Conversion of Sugars and Polysaccharides to 5‐Chloromethyl Furfural.

AbstractA range of carbohydrates such as fructose (I) and glucose (III) are rapidly and selectively converted to furfural derivative (III) using microwave heating in a biphasic reaction system.

Synthesis of Long Chain Brønsted Acidic Ionic Liquids

With the depletion of petroleum, a new source of feedstock chemicals for polymers is needed. The new source should be a renewable source to avoid future depletion and environmental impact. A potential source of new feedstock chemicals is chitin. The use of ionic liquids for the dissolution of chitin has enabled new processing methods for this biopolymer. Recent results demonstrate that chitin can be depolymerizes in ionic liquid. The products of this depolymerization are N-acetylglucosamine and a furfural derivative. This research investigates the use of ionic liquids and various acid catalysts for the depolymerization of chitin into its monomer units. This research evaluates the effects of temperature, the nature of the catalyst, and solvent effects on the depolymerization of chitin.

Simultaneous determination of iridoid glycosides, phenethylalcohol glycosides and furfural derivatives in Rehmanniae Radix by high performance liquid chromatography coupled with triple-quadrupole mass spectrometry

In this study, a sensitive and selective method for simultaneously quantifying eight major components (four iridoid glycosides, three phenethylalcohol glycosides and one furfural derivative) of Rehmanniae Radix by high performance liquid chromatography coupled with triple-quadrupole mass spectrometry (HPLC–TQ-MS) was developed. The sample preparation was executed using an optimised ultrasonic method with complete extraction efficiencies of eight analytes. For mass spectrometry, selected ion recording (SIR) scan mode was used to improve the sensitivity and selectivity. The established method was validated in terms of linearity, sensitivity, precision, accuracy and stability, and successfully applied to determine the contents of the eight analytes in different batches of raw and processed Rehmanniae Radix, which confirmed that the established method was reliable and useful for “holistic” quality evaluation of Rehmanniae Radix. The quantitative results indicated that the quality of commercial raw or processed Rehmanniae Radix was remarkably inconsistent.

Scientific Opinion on Flavouring Group Evaluation 218, Revision 1 (FGE.218Rev1): alpha, beta‐Unsaturated aldehydes and precursors from subgroup 4.2 of FGE.19: Furfural derivatives

Scientific Opinion on Flavouring Group Evaluation 218, Revision 1 (FGE.218Rev1): alpha, beta‐Unsaturated aldehydes and precursors from subgroup 4.2 of FGE.19: Furfural derivatives

Formation of furans upon electron-beam heating of cellulose

Similarity between cotton cellulose and sulfate and sulfite pine celluloses in degradation during electron-beam distillation has been shown. The yield of the distillate liquid slightly depends on the type of cellulose and makes up ∼60 wt %. The product liquid contains organic compounds with molecular masses of 32 to 128, of which furfural and its derivatives prevail. Electron-beam distillation can be used as an effective method for the manufacturing of furfural and other furan derivatives from cellulose (along with the traditional pentosan conversion processes). It has been shown that grinding and preheating of cellulose lead to an increase in the proportion of furfural and other furans in the condensates.

Assessment of furfurol derivatives: food risk factors in natural apricot and peach juice

Chemical risk factors increase with the diversification of “aggressive” processing technologies of raw matter. Furfurol and its derivatives accidentally present in finite food products due to the poor thermal process (soaking in boiling water, pealing etc.) of apricots (Prunus armeniaca) and peach (Prunus persica) rich in hexoses and pentoses (whole alimentary fibbers) are, from this perspective, a major chemical risk more and more frequently noticeable due to their negative effects. This paper aims to report the potential existence of these compounds in the natural extract of apricot and/or peach cultivated in Western Romania (the Timiş County) as a result of “aggressive” treatments during the soaking in boiling water, pealing, sugar preserving etc. processing. The extract contains between 4.1-8.8% sugars, 0.26-0.51% low organic acids (malic, citric, tartric), 1.43-4.57% cellulose and hemicelluloses. Their thermal processing favors inner acid hydrolysis (malic, citric, and tartric acids) of cellulose and hemicelluloses (hexoses, pentoses) up to furfural (F) (CAS 98 – 01 – 1) 5 (hydroxymethyl) furfural (5 – HMF) (CAS 67 – 47 – 0) and other furanic derivatives with variable share depending on working parameters. Determination was made by colorimetric assessment of color compounds) made up through the condensation of diphenylamine (CAS 122 – 39 – 4) with furfural and 5 – (hydroxymethyl) furfural within the spectral interval 490-680nm. The results confirm the presence of furfural derivatives in natural extracts from apricot and peach processed thermally at temperatures above 100°C. The detection limit is 5g/mL. The method reproducibility is ±0.3%. The soaking in boiling water, the technological vapour or hot water pealing and the low organic acids (tartric, malic, citric) in the fruits and the extracts, respectively, directly influence the share of furfural derivatives.

Cellulose destruction by electron-beam-induced heating

An efficient method for producing furfural and other furan derivatives from cellulose was proposed. Radiolytic destruction of cotton cellulose, sulfate and sulfite pine celluloses, and carboxymethylcellulose was studied under electron-beam-induced distillation conditions. The yield of the liquid distillate from cellulose of various origin was about 60%. Furfural and its derivatives with the molecular weight up to 140 were the predominant products. Grinding and preheating of cellulose increase the fraction of furan derivatives in the condensate. The liquid products are partially transformed into high-molecular-weight compounds that are distilled with difficulty and that are involved in the formation of wood charcoal in the yield of about 20%.

Understanding Catalytic Biomass Conversion Through Data Mining

Catalytic conversion of biomass is a key challenge that we chemists face in the twenty-first century. Worldwide, research is conducted into obtaining bulk chemicals, polymers and fuels. Our project centres on glucose valorisation via furfural derivatives using catalytic hydrogenation. We present here new results for a set of 48 bimetallic catalysts supported on silica, and demonstrate the application of data mining tools to identify major trends in the data. These results are combined with a full factorial data set for the hydrogenation of 5-ethoxymethylfurfural over alumina-supported transition metal catalysts. All the catalysts in the combined datasets were synthesized and tested for performance under identical conditions. This, combined with the fact that no combinations of metals were left out, enables the use of advanced data mining tools. The paper describes the data and highlights the relevant trends from a chemist’s viewpoint.

Effect of Thermal Treatment and Oak Chips on the Volatile Composition of Pedro Ximénez Sweet Wines

Young, sweet Pedro Ximénez wines were thermally treated at 65°C for 10, 20, or 30 days to reduce their overall oxidative aging time. Volatile aroma compounds associated with typical aroma descriptors of aged Pedro Ximénez wines were determined by gas chromatography-mass spectrometry. Formation of Maillard reaction products, including furfural derivatives, dihydromaltol, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, increased during the thermal treatment, while others, such as 2-methoxy-4-vinylphenol, decreased. Wines containing oaks chips had increased concentrations of compounds that contribute to oak and vanilla aromas. Based on these results, thermal treatment of Pedro Ximénez wines may be an effective method to shorten oxidative aging time, thus allowing a possible decrease in production costs.

Implementation and Optimization of DFT-D/COSab with Respect to Basis Set and Functional: Application to Polar Processes of Furfural Derivatives in Solution

The implementation, optimization, and performance of DFT-D, including the effects of solvation, has been tested on applications of polar processes in solution, where dispersion and hydrogen bonding is known to be involved. Solvent effects are included using our ab initio continuum solvation strategy, COSab, a conductor-like continuum solvation model, modified for ab initio in the quantum chemistry program GAMESS. Structure and properties are investigated across various functionals to evaluate their ability to properly model dispersion and solvation effects. The commonly used S22 set with accurate interaction energies of organic complexes has been used for parametrization studies of dispersion parameters and relevant solvation parameters. Dunning's correlation consistent basis sets, cc-pVnZ (n = D, T), are used in the optimization, together with the Grimme B97-D exchange-correlation functional. Both water (ε = 78.4) and ether (ε = 4.33) environments are considered. Optimized semiempirical dispersion correction parameters and solvent extent radii are proposed for several functionals. We find that special parametrization of the semiempirical dispersion correction when used together in the DFT-D/COSab approach is not necessary. The global performance is quite acceptable in terms of chemical accuracy and suggests that this approach is a reliable as well as economical method for evaluation of solvent effects in systems with dispersive interactions. The resulting theory is applied to a group of push-pull pyrrole systems to illustrate the effects of donor/acceptor and solvation on their conformational and energetic properties.

Role of Roasting Conditions in the Profile of Volatile Flavor Chemicals Formed from Coffee Beans

The volatile chemicals in dichloromethane extracts from green coffee beans, roasted at 230 degrees C for 12 min (light), at 240 degrees C for 14 min (medium), at 250 degrees C for 17 min (city), or at 250 degrees C for 21 min (French), were analyzed by gas chromatography and gas chromatography-mass spectrometry. Among the 52 volatile compounds identified, the major compounds were 5-hydroxymethylfurfural, furfuryl alcohol, and 6-methyl-3,5-dihydroxy-4H-pyran-4-one in light-roasted beans; furfuryl alcohol, 5-hydroxymethylfurfural, and gamma-butyrolactone in medium-roasted beans; furfuryl alcohol, gamma-butyrolactone, and 2-acetylpyrrole in city-raosted beans; and gamma-butyrolactone, furfuryl alcohol, and catechol in French-roasted beans. Furfural derivatives and furanones were yielded in relatively high concentrations under mild roasting conditions and then reduced at higher roasting intensities. More pyridines and pyrroles were formed by high roasting intensities than by mild roasting intensities. Chlorogenic acid degradation products, phenols, and a lactone were produced more by high roasting intensities than by low roasting intensities. The results of the present study suggest that controlling the roasting conditions according to the formation of particular chemicals can prepare a roasted coffee with preferable flavor.

Direct, High‐Yield Conversions of Cellulose into Biofuel and Platform Chemicals—On the Way to a Sustainable Biobased Economy

Steering away from alcohol: Fermentation of carbohydrates to ethanol might not be the best way to utilize biomass for the production of fuels and platform chemicals. Two different new remarkable approaches lead to polyols or furfural derivatives.

Flavouring Group Evaluation 218: alpha, beta-Unsaturated aldehydes and precursors from subgroup 4.2 of FGE.19: Furfural derivatives - Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC)

Flavouring Group Evaluation 218: alpha, beta-Unsaturated aldehydes and precursors from subgroup 4.2 of FGE.19: Furfural derivatives - Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC)

Synthesis and Structural Pattern Recognition of 5-(2'-Alkoxycarbonyl-substituted phenoxy)furfural Derivatives

The ethyl 5-(2'-alkoxycarbonyl-substituted phenoxy)furan-2-carboxylates (1C-13C) showed good anti-platelet aggregation,(1)) anti-allergic(2)) and anti-inflammatory activities.(2)) A series of 5-(2'-alkoxycarbonyl-substituted phenoxy)furfurals (1F-13F) were prepared for comparing the above activities. The objectives of this research are the synthesis and structural pattern recognition of compounds 1F-13F. The Silica Gel 60 column chromatography method was employed to separate and purify pure compounds 1F-13F by three solvent systems. For the structure elucidation of compounds 1F-13F, four spectroscopic methods were used: electron impact mass (EI-MS), UV-VIS, IR and NMR spectrometers. With the help of spectrometers, investigations can be performed on spectroscopic data. A simple methodology for recognizing structural patterns was carried out with the aid of statistical analysis designed to establish the classification model of the structural skeleton in this research. It was found that compounds 1C-13C and 1F-13F have similar chemical profiles and are clustered into one group. The pattern plots revealed valuable information and showed good correlation between compounds 1C-13C and 1F-13F. These findings correlate directly with the resulting spectroscopic data. These results with those obtained by EI-MS and NMR patterns give insight into a reliable pattern recognition for determining both 1C-13C and 1F-13F skeletons.

Enantiomerically pure tetrahydroisoquinolines by enzyme catalysis and gold-catalyzed phenol synthesis

Five different furfural derivatives were converted to chiral cyanohydrins by enzyme catalysis in good enantiomeric excess. After a sequence of silyl protection, nitrile reduction, tosylation and propargylation, substrates for the gold(I) catalyzed cycloisomerization of δ-alkynyl furans delivered good yields of enantiomerically pure dihydroxytetrahydroisoquinoline building blocks. Neither racemization nor elimination to quinolines was observed.

The Inhibition of C-steel Corrosion in H3PO4Solution by Some Furfural Hydrazone Derivatives

The effect of some furfural hydrazone derivatives (I -V) as corrosion inhibitors for C-steel in 3M H 3 PO 4 solution in which M indicates mol/l has been studied using weight-loss and galvanostatic polarization techniques. A significant decrease in the corrosion rate of C-steel was observed in the presence of the investigated compounds. This study revealed that, the inhibition efficiency increases with increasing the inhibitor concentration, and the addition of iodide and thiocynate ions enhances it to a considerable extent. The effect of temperature on the corrosion behavior of C-steel was studied in the range from 30-60°C with and without 5×10 -6 M investigated compounds using weight-loss method. Apparent activation corrosion energy (E a *) and other thermodynamic parameters for the corrosion process were calculated and discussed. The polarization measurements show that the investigated compounds act as mixed-type inhibitors, but the cathode is more polarized when an external current was applied. The adsorption of these compounds on the surface of C-steel in 3 M H 3 PO 4 obeys Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the investigated compounds.

Chemical investigations on the thermal behaviour of wood during friction welding

Friction welding is a new technology in the course of which wood pieces are subjected to circular or linear movements in a welding machine. The wood in the contact zone is heated and melted. Aiming at a better understanding of the thermal alteration of wood and the formation of a viscous layer acting as adhesive, the thermally changed material was taken to be analysed by chemical and spectroscopic methods. As a manifestation of thermally splitting of wood, the total amount of extractable compounds within the joint material (JM) is higher than that of unaltered spruce. Cellulose was found less altered than the other essential wood components. Polyoses, on the other hand, are less stable under the conditions of friction welding; they are detectable only in small amounts in the altered zone. Lignin also suffers distinct changes as demonstrated by the increase of free phenolic groups and the decrease of the typical bonds between the phenolpropane units. Furan derivatives were detected within the volatiles of the smoke gas, arising mainly from the polyoses. It is obvious that reactions between furfural and other furan derivatives with lignin belong to the main reactions in the friction zone leading to cross-linking of the JM.

Theoretical model of internal rotation in monosubstituted derivatives of furfural.

The present work explores the effect of substitution in all free positions of furfural on conformational preferences of formyl group by using ab-initio calculations at the MP2/6-31G(p,d) level of theory. Theoretical modeling was made in vacuo. The selected substituents were -CH(3), NH(2), NO(2) and F groups in 3, 4, 5 and ipso carbonyl positions. Geometries of all derivatives were analyzed and it is ascertained that substitution has not important consequences on furan ring geometry. Differences of energy between OO-cis and trans conformers and energy barriers between them are described and extreme cases are explained. Interesting features appear in the cases of -NH(2) and -NO(2) groups, and particularly when the 3 and ipso carbonyl positions are substituted. Variations in energy barriers are correlated with variations in C2-C6 distances for the transition states and planar forms. Substitution effect on Mülliken charges are analyzed and related with internal rotation energy barriers and differences between conformers.

Chemical constituents from the Hydrangea chinensis.

Two quinazolone alkaloids, (+)-febrifugine (1) and isofebrifugine (2), along with three coumarin derivatives, 6-hydroxy coumarin (3), skimmin (5), and umbelliferone-7-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranoside (6), were isolated from the roots of Hydrangea chinensis. Compound 6 is a new compound. In addition, umbelliferone (4), linoleic acid (7), two steroidal glycosides (8, 9), three furfural derivatives (10-12), and butyl-beta-D-fructofuranoside (13) were isolated from the leaves of the same plant. The structures of all isolates were elucidated by spectral methods.