• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.1
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• pp.27-34
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• 2013

Quantitative analysis of 5-hydroxymethylfufural (5-HMF) conversion from fructose by dehydration and rearrangement was investigated by $^1H$-NMR spectroscopic method. Fructose was converted to 5-HMF in dimethylsulfoxide (DMSO)-$d^6$ or acidic deuterium hydroxide at controlled reaction temperature and time. With addition of internal standards (biphenyl for DMSO-$d^6$ solvent, and 2,5-dihydroxybenzoic acid for deuterium oxide solvent), conversion from fructose to 5-HMF was analyzed by $^1H$-NMR spectroscopy. Quantitative analysis was run by comparison with peak area integration between of 5-HMF and internal standard. In DMSO solvent, 5-HMF was stable end product but part of 5-HMF was converted to formic and levulinic acid at acidic aqueous medium.

• Journal of Life Science
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• v.19 no.12
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• pp.1836-1840
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• 2009

Recently, hydroxymethylfurfrual (HMF) has been highlighted as a key intermediate for the production of liquid biofuels and other valuable compounds. We used sesame roots as a biocatalyst to synthesize HMF using flask cultures. The synthesis of HMF was identified by GC-mass analysis. The highest root growth was observed in cultures with 1.0 mg/l NAA at $30^{\circ}C$, while root growth was not found in those without NAA treatment. When silver nitrate ($AgNO_3$) was added, the root growth was greatest in those treated with 0.5 mg/l $AgNO_3$ and cultured at $30^{\circ}C$. In the case of HMF synthesis, its highest yield was obtained in those treated with 0.5 mg/l NAA at $25^{\circ}C$, but low HMF was detected in those treated without naphthaleneacetic acid (NAA). The addition of $AgNO_$ to the culture medium showed a 8-10% reduction in HMF yield compared to that of the control, indicating its inhibitory effect on the synthesis of HMF. On the whole, an optimal culture temperature for HMF synthesis seemed to be between $25-30^{\circ}C$.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.2
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• pp.21-26
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• 2013

Conversion of fructose to 5-hydroxymethylfurfural (5-HMF) was investigated in dimethylsulfoxide (DMSO) solvent with increasing reaction temperatures and impact of residual water from dehydration reaction byproduct. To convert fructose to 5-HMF, increasing reaction temperature led more conversion to 5-HMF than lower temperature at the range of $120-150^{\circ}C$ in DMSO solvent. DMSO engaged in the acid-catalyzed dehydration and rearrangement reaction as acid and solvent. Increasing temperature led to more furanose structure than pyranose at the range of $30-80^{\circ}C$. Formed 5-HMF could be degraded to levulinic and formic acid at the presence of acid and water. Removal of water in reaction medium could prevent 5-HMF degradation.

• Korean Journal of Oriental Medicine
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• v.9 no.1
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• pp.129-135
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• 2003

Rehmanniae Radix Preparata attributes good blood circulation and it has been used for the treatment of dizziness, men's sterility, excessive loss of blood and weakness. On the quality control of commercial Rehmanniae Radix Preparata, quantitative determination of 5-hydroxymethyl (5-HMF) using HPLC method has been conducted. Quantitative analysis of S-hydroxymethyl-2-furaldehyde (5-HMF) in commercial Rehmanniae Radix Preparata showed average of $0.136{\pm}0.057%$ in 14 samples collected throughout the regions of Korea.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.193-201
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• 2022

5-HMF(5-Hydroxymethylfurfural) and LA(levulinic acid) derived from biomass are green platform chemicals, which have a wide of potential applications as biofules and biochemicals. In this study, the kinetics of LA formation from glucose decomposition with various concentration of sulfuric acid at different temperature was investigated. The experiments were performed in a broad temperature (140-200 ℃), using H₂SO₄ (1-3 wt%) as the catalyst. Glucose solution was made by dissolving 1 g of glucose in 10 ml of H₂SO₄ solution. The reactions rates increased with temperature and the activation energy showed a similar tendency to previous reported values. Reaction time for maximum concentration of 5-HMF decreased as the temperature increased. Furthermore, the decomposition of 5-HMF was fast as the acid concentration increased. Reaction time to reach maximum concentration of levulinic acid was reduced as the acid concentration increased. Continuing to raise the temperature decreased the maximum concentration of levulinic acid and increased the amount of humins. On the basis of results, kinetic parameters help to understand mechanism of LA and 5-HMF. In addition, this study provides useful information to achieve high concentration of LA and 5-HMF from biomass.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.705-715
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• 2016

The main aim of this study was to investigate the potential of wood charcoal on removing furan compounds (5-hydroxymethylfurfural (5-HMF), furfural) known as fermentation inhibitors in sugar hydrolysates obtained from supercritical water treatment of lignocellulosic biomass. For this aim, model hydrolysate was prepared, and removal rates of sugars or furan compounds depending on wood charcoal concentration and treatment time were calculated and analyzed in comparison with the case of activated carbon. 0.5, 1, 2, 4, 8, or 12% (w/v) of wood charcoal or activated carbon was loaded into the model hydrolysate, containing glucose, xylose, 5-HMF, and furfural, and treatment was conducted for 1, 3, 6, 12, or 24 h. After treatment, removal rates of 5-HMF and furfural gradually increased as wood charcoal concentration or treatment time increased, and over 95% of 5-HMF and furfural were removed at 8% of wood charcoal concentration and 3 h of treatment time, while the loss of sugars (< 2%) was hardly observed. On the other hand, in the case of activated carbon treatment, removal rates of 5-HMF and furfural were over 95% at mild condition (activated carbon concentration: 8%, treatment time: 1 h), but over 10% of glucose and xylose were removed. Therefore, considering sugar production and further process applied sugar, the wood charcoal treatment of sugar hydrolysate was more effective for removing furan compounds and maintaining the sugar yield.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.84-88
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• 2011

Some thermally processed foods have higher biological activities due to their various chemical changes during heat treatment. Especially, 5-hydroxymethylfurfural (HMF) is derived from dehydration of sugars and has been identified in processed garlic. The biological function of HMF have revealed as antisickling agent and thyrosinase inhibitor. This study was carried out to examine the formation of HMF and free sugars from the aged garlics when it is treated at 60 and $75^{\circ}C$ and different incubation periods from 7 to 35 days. HMF and free sugars from the hot-water extracts of aged garlics were analyzed with GC/MS, LC/MS, and HPLC. The amount of HMF was higher than at $75^{\circ}C$ and increasing incubation period. Among free sugars, the only fructose except glucose and sucrose was formed and converted to HMF at high temperature and long incubation period. However, fructose formed in low temperature during making of aged garlic was rarely converted to HMF. This result indicates that formation of HMF can be dependent on the temperature and incubation period for making aged garlic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1748-1752
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• 2004

This study was performed to obtain the good processing in the Relunanniae Radix Preparata. The contents of the Relunanniae Radix and the Relunanniae Radix Preparata produced through different processes were analyzed in the 5-hydroxymethyl-2-furaldehyde (5-HMF), sugar, total nitrogen, crude lipid and ash. 5-HMF was not detected in the Relunanniae Radix, but detected in the Relunanniae Radix Preparata. 5-HMF content was increased gradually with processing times (1∼9 times) and increased expressly in the Relunanniae Radix Preparata steamed for 7 times. Sucrose, fructose and glucose were contained in the Relunanniae Radix, but sucrose was not detected and fructose and glucose were increased largely in the Relunanniae Radix Preparata steamed for 1 time. Fructose and glucose were decreased gradually with processing times (2∼9 times), but the gap of decrease was insignificant. Total nitrogen was changed slightly and crude lipid was decreased slowly with processing times. The ash was suitable to KPⅧ rules (less than 6.0%). From this analysis we found out the content of 5-HMF from Relunanniae Radix Preparata steamed more than 7 times was suitable to KPⅧ rules (more than 0.1%).

• Clean Technology
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• v.20 no.2
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• pp.108-115
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• 2014

Various metal chlorides and acid catalysts in ionic liquid solvent were investigated to directly convert cellulose into 5-hydroxymethylfurfural (5-HMF). Metal chlorides containing Sn(II), Zn(II), Al(III), Fe(III), Cu(II), and Cr(III) were used and acidic ionic liquid immobilized on silica gel as an acid catalyst and commercial acid catalysts (sulfuric acid, chloric acid, Amberlyst-15,DOWEX50x8) were used for comparison studies. The acid strength and amount of acid catalysts were probed with Hammett indicator. The selectivity and yield of 5-HMF were determined with reaction temperature, reaction time and catalyst ratio. A catalyst containing $CrCl_3-6H_2O$ and $SiO_2-[ASBI]HSO_4$ showed the highest selectivity and it was found that this catalyst had higher activity than commercial solid acid catalysts such as Amberlyst-15 and DOWEX50x8. The selectivity of 5-HMF appeared to be mainly dependent on the acid strength and catalyst ratio, it was found that levulinic acid was produced from 5-HMF by rehydration.

• Korean Journal of Pharmacognosy
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• v.32 no.2 s.125
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• pp.116-120
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• 2001

In order to determine the content of 5-hydroxymethyl-2-furaldehyde (5-HMF) in the Rehmanniae Radix Preparata, 5-HMF was isolated from the EtOAc fraction of the Rehmanniae Radix Preparata samples and identified by spectroscopic and physicochemical evidences. Twenty one samples prepared on the basis of increasing number of stewing times with wine were analyzed by HPLC. From this analysis, it was revealed that the samples processed under one to nine times of stewing showed increasing pattern in 5-HMF contents. And the samples processed under 9 to 18 times of stewing showed 0.53-0.74% in 5-HMF contents. However, for those samples processed more than 19 times, 5-HMF content profile showed decreasing pattern.