• 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 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.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.204.1-204.1
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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 the commercial Rehmanniae Radix Preparata, quantitative determination of 5-hydroxymethyl-2-furaldehyde (5-HMF) using HPLC method has been conducted. Quantitative analysis of 5-HMF in Rehmanniae Radix Preparata showered average 0.121${\pm}$0.063% in 14 samples collected throughout the regions of Korea. Contents of loss on drying, residue on ignition and residue on acid insoluble ignition showered average 14.084${\pm}$2.804%, 3.415${\pm}$0.790% and 0.807${\pm}$0.474% respectively.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.899-910
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• 2021

This study was performed to suggest concentration methods leading to the production ofhoney with an excellent flavor by examining the effects of the concentration temperature and method on changes in 5-hydroxymethyl-2-furaldehyde (5-HMF) levels and the flavor components of honey. The 5-HMF contents of honey samples concentrated in a tray concentrator at 45, 50, 60, and 70℃ were 2.1, 2.3, 2.5, and 3.1 mg·kg^-1, respectively, demonstrating that the 5-HMF contents increased as the concentration temperatures were increased. The honey vacuum-concentrated at 70℃ showed a higher 5-HMF content than that at 60℃, similar to the tray-concentrated honey at different temperatures. The main and other minor flavor components of the honey were volatilized and significantly reduced after vacuum concentration. In the tray concentration, all of the honey samples concentrated at 40, 50, 60, and 70℃ showed flavor component patterns similar to each other, and most of the main and other minor flavor components in the honey were volatilized and significantly reduced after tray concentration. As such, most of the main and other minor flavor components of the honey were mostly removed at 70℃ after both the vacuum concentration and tray concentration processes. The effects of the concentration method and temperature on the viscosity, 5-HMF level, and flavor components of the honey were found to be significant in this study. Given that the components of honey were shown to undergo significant physicochemical changes depending on the concentration method used and temperature during laboratory-scale production, the concentration methods devised in this study can be applied industrially.

• YAKHAK HOEJI
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• v.22 no.1
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• pp.1-7
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• 1978

Two yellowish oily liquid compounds, $C_{6}H_{6}O_{3}$(A) bp $189^{\circ}$, $n^{20}_{D}$ 1.3697 and $C_{7}H_{8}O_{3}$(D) bp $164^{\circ}$, $n^{20}_{D}$1.5075, were isolated from root of Codonopsis pilosula (Franch.) Nannfeldt (Campanulaceae). Their structures were identified as 5-(hydroxymethyl)-2-furaldehyde(A) and 5-(methoxymethyl)-2-furaldehyde(D). The latter is a new compound among the known natural products.

• Korean Journal of Pharmacognosy
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• v.42 no.2
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• pp.117-126
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• 2011

Twenty-two compounds were isolated from the 70% ethanolic extract of Rehmanniae Radix Preparata (Scrophulariaceae) and their structures were identified as three triterpenoids [oleanolic acid (1), pomonic acid (2) and ursolic acid (5)], an iridoid, catalpol (13), four furan derivatives [5-hydroxymethyl-2-furaldehyde acetate (3), 5-hydroxymethyl-2-furfural (6), 5-hydroxymethyl-2-furancarboxylic acid (7), and 5-(${\alpha}$-D-galactopyranosyloxymethyl)-2-furancarboxaldehyde (15)], three phenethyl alcohol glycosides [darendoside B (14), phenethyl alcohol 2-O-${\beta}$-D-xylopyranosyl(1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (17), and salidroside (19)], four sugar derivatives [L-arabinose (11), raffinose (20), stachyose (21), and mannitol (22)], and seven others [2,5-dihydroxyacetophenone (4), succinic acid (8), daucosterol (9), ${\beta}$-sitosterol (10), adenosine (16), uridine (18) jio-cerebroside (12)]. The chemical structures of these compounds were identified on the basis of spectroscopic methods and comparison with literature values. This is the first report of the triterpenoids oleanolic acid (1), pomonic acid (2), and ursolic acid (5) from the genus Rehmannia, as well as the first report of compounds 5-hydroxymethyl-2-furaldehyde acetate (3), 2,5-dihydroxyacetophenone (4), daucosterol (9), darendoside B (14), 5-(${\alpha}$-D-galactopyranosyloxymethyl)-2-furancarboxaldehyde (15), adenosine (16), phenethyl alcohol 2-O-${\beta}$-D-xylopyranosyl(1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (17), and salidroside (19) from the Rehmanniae Radix Preparata.

• Korean Journal of Oriental Medicine
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• v.4 no.1 s.4
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• pp.115-127
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• 1998

To improve the quality control of frequently used oriental medicinal plants, the storage, cutting, processing and decokting methods of Rehmannia glutinosa Libosch. var. purpurea Makino(熟地黃) were examined. The contents of 5-hydroxymethyl-2- furaldehyde(5-HMF) of Rehmannia glutinosa Libosch. var. purpurea Makino were analysed by HPLC at various conditions as the standard component. Raw materials were classified into 3 groups with their specific gravity(天 地 人黃) and determined the ding weights and the contents of water, the solid component of Ji-Hwang(地黃) was the most. Rehmannia glutinosa Libosch. var purpurea Makino was steamed and dried nine times and analysed the content of 5-HMF on every time. In the case of Ji-Hwang, the standard component of the ninth sample was produced the most. But which of the tenth samples of Chun-Hwang and Yin-Hwang(天黃 人黃) were the most. The best decokting conditions which were determined by the yield of 5-HMF were as follows : non cutting, soaking time was 0 minutes, decokting time was 75 minutes after boiling. The contents of sugar on each of samples were determined. The contents of standard component increased by steaming number and the contents of sugar decreased.

• Analytical Science and Technology
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• v.37 no.5
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• pp.295-305
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• 2024

5-Hydroxymethyl-2-furaldehyde (5-HMF) is considered one of the main quality indexes of various food products. Its metabolism in humans can potentially lead to carcinogenic compounds. Metallic ions such as Zn, Mg, Mn, and Fe have been reported to enhance 5-HMF formation. Recently, studies on adsorbents that can extract specific organic and inorganic substances with one adsorbent have been conducted. However, simultaneous analysis of organic and inorganic materials typically requires distinct pre-treatment and analytical methods, which increase a lot of labor and cost. In this study, hybrid imprinted polymer (HIP) by mixing 5-HMF imprinted polymer (FIP) and zinc ion imprinted polymer (ZIIP) were generated to extract two analytes, Zn ion and 5-HMF, simultaneously. Physicochemical characterization of HIP was conducted by Fourier-transform infrared spectroscopy, scanning electron microscopy, and sorption tests. Extraction conditions including adsorbent mixing ratio, adsorbate mixing range, and equilibrium time were optimized. Freundlich adsorption model was as the best-fitting isotherm model to elucidate the adsorption mechanism. Affinity of Zn ion and 5-HMF on HIP was superior to non-HIP. In conclusion, HIP showed reasonable feasibility that could be used as an adsorbent to be used for simultaneous extraction of organic and inorganic compounds present in the sample.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.9
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• pp.1561-1565
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• 2007

According to thermal degradation on power transformers, it is known that electrical, mechanical and chemical characteristics for power transformer's oil-paper are changed. In the chemical property, especially, when the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. Also the paper breakdown is accompanied by an increase in the content of various furanic compounds within the dielectric liquid. It is known that furanic components in transformer oil come only from the decomposition of insulating paper rather than from the oil itself. Therefore the analysis of furanic degradation products provides a complementary technique to dissolved gas analysis for monitoring transformers when we evaluate the aging of insulating paper by the total concentration of carbon monoxide and carbon dioxide dissolved in oil only. Recently, the analysis of furanic compounds by high performance liquid chromatography(HPLC) using IEC 61198 method for estimating degradation of paper insulation in power transformers has been used more conveniently for assessment of oil-paper. It is know that the main products which is produced by aging are 2-furfuryl alcohol, 2-furaldehyde(furfural), 2-furoic acid, 2-acetylfuran, 5-methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde. For investigating the accelerated aging process of oil-paper samples we manufactured accelerating aging equipment and we estimated variation of insulations at $140^{\circ}C$ temp. during 500 hours. Typical transformer proportions of copper, silicon steel and iron have been added to oil-paper insulation during the aging process. The oil-paper insulation samples have been measured at intervals of 100 hours. Finally we have analyzed that 2-furoic acid and 2-acetylfuran products of furanic compounds were detected by HPLC, and their concentrations were increased with accelerated aging time.

• Natural Product Sciences
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• v.18 no.3
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• pp.200-203
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• 2012

The chromatographic separation of a methanol extract of Prunus mume (Rosaceae) led to the isolation of 5-hydroxymethyl-2-furaldehyde (1), 4-O-caffeoylquinic acid methyl ester (2), prunasin (3), 5-O-caffeoylquinic acid methyl ester (4), benzyl-O-${\beta}$-D-glucopyranoside (5), and liquiritigenin-7-O-${\beta}$-D-glucopyranoside (6). Their structures were determined by 1D, 2D-NMR and MS data analysis as well as by comparison of their data with the published values.