• Journal of the Korean Wood Science and Technology
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• v.19 no.3
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• pp.72-76
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• 1991

The new preparative separation techneque of dihydroquercetin (2, 3-trans-dihdroxy-3, 3', 4', 5, 7-pentahydroxydihydroflavonol) was investigated by liquid chromatography. Also some typical coniferous wood bark were examined for the sources of dihydroquercetin. The good sources of dihydroquercetin were Douglas-fir[Pseudotsuga menziesii] bark and pitch pine [Pinus rigida] bark. There is no dependance the produced place and species dihyroquercetin which is separated by silica-gel column chromatography was taken with white needle-like crystals. This crystals were very stable in the humidity and on the light. It also can stored very long without derivatives.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.84-86
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• 1999

From the ethyl acetate fraction of the methanol extract of the fruits of Opuntia ficus-indica var. saboten, two dihydroflavonois were isolated and identified as (+)-trans-dihydrokaempferol (1) and (+)-trans-dihydroquercetin (2) by spectroscopic methods.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.94-99
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• 1995

현사시나무의 목질부와 수피부를 아세톤-물(1:1)의 혼합용액으로 추출하고 Sephadex LH-20로 충진한 칼럼을 사용하여 4개의 후라보노이드, 즉 (+)-catechin, (+)-dihydroquercetin, eriodictyol 및 (+)-dihydrokaempferol을 단리하고 $^{13}C$-NMR과 $^1H$-NMR 스펙트럼을 이용하여 그 구조를 규명하였다. 단리된 화합물의 A-환은 모두 후로로그루시놀형으로, B-환은 카테콜형 또는 페놀형으로 구성되어 있으며 (+)-dihydroquercetin, (+)-dihydrokaempferol과 eriodictyol은 포플라속의 수종에서는 처음으로 단리 되었다.

• Biomedical Science Letters
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• v.28 no.4
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• pp.322-326
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• 2022

The purpose of this study was to develop hydrolysate from silkworm (Cudrania Silkworm Fibroin Peptide; CSFP), a food containing components for improving blood vessel health. In general, Cudrania tricuspidata leaves contain about 5 times more rutin and 25 times more dihydroquercetin than mulberry leaves. 1-Deoxynojirimycine (1-DNJ), dihydroquercetin and rutin inhibit the activity of carbohydrate-digesting enzymes, inhibit blood lipid peroxidation, and regulate insulin secretion, which helps blood vessels to be healthy. When the diet-controlled silkworm was enzymatically hydrolyzed, it was confirmed that rutin content was about 8 times higher than that of the in general silkworm as a control. In the silkworm hydrolysate, CSFP, developed as a final food material, the active ingredients were 65 mg/kg for rutin, 3,328 mg/kg for DNJ, 0.43 mg/kg for dihydroquercetin, and 82,624 mg/kg for total polyphenol, which was confirmed through LC-MS/MS analysis. In conclusion, it was found that silkworms fed with C. tricuspidata leaves as a diet had more active components that can help control blood sugar and improve blood vessel health than silkworms fed with mulberry leaves.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.73-79
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• 1991

The flavonoids from plants is very widly used as natural dye for food and medicine etc. In this study, red pine which is widespread in Korea was studied to find new chemicals which may use as raw material for the special purpose. The fIavonoids of red pine bark were separated with Sephadex LH-20 and Toyo pearl HW-40F as packed materials and the structure of separated f1avonoids was determined by $^1H$-and $^{13}C$-NMR spectroscopy. The (+) catechin which is widespread in nature and dihydroquercetin-3'-0-${\beta}$-galactoside were found in red pine bark. The dihydroquercetin-3'-0-${\beta}$-galactoside is newly found in this species.

• YAKHAK HOEJI
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• v.53 no.6
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• pp.351-356
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• 2009

Sakuranetin, prunetin and dihydroquercetin were isolated from the methanol extract of Sorbus commixta by 1D/2D-NMR and LC-MASS spectrometry. Medicating these compounds to RAW264.7 cell that was pre-treated by lipopolysaccharide revealed anti-inflammatory effects that greatly inhibited the production of NO (nitric oxide) and PEG2 (prostaglandin E2), which are well known to cause the expression of iNOS (inducible nitric oxide synthase) and COX-2 (Cyclooxygenase-2). These results suggest that these compounds can be used as stable anti-inflammatory materials.

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.1018-1023
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• 2003

From the stems and fruits of Opuntia ficus-indica var. saboten, eight flavonoids, kaempferol (1), quercetin (2), kaempferol 3-methyl ether (3), quercetin 3-methyl ether (4), narcissin (5), (+)-dihydrokaempferol (aromadendrin, 6), (+)-dihydroquercetin (taxifolin, 7), eriodictyol (8), and two terpenoids, (6S,9S)-3-oxo-$\alpha-ionol-\beta$-D-glucopyranoside (9) and corchoionoside C (10) were isolated and identified by means of chemical and spectroscopic. Among these isolates, compounds 3∼5 and 8∼10 were reported for the first time from the stems and fruits of O. ficusindica var. saboten.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.517-524
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• 2011

Eleven polyphenolic compounds, including procatechuic and chlorogenic acids, (+)-dihydroquercetin, rutin, isoquercitrin, quercitrin, (+)-dihydrokaempferol, trans-resveratrol, moracin, quercetin and 4-prenylmoracin were isolated and purified from the methanolic extract of defatted mulberry seed residue by a series of column chromatography including silica gel, Sephadex LH-20, and ODS-A, and their chemical structures were identified by spectral analysis. The antioxidant activities of the eleven isolated polyphenolic compounds were measured spectrophotometrically using DPPH radical. Among the eleven polyphenolic compounds tested, rutin ($IC_{50}=20.2\;{\mu}M$), isoquercitrin ($IC_{50}=22.5\;{\mu}M$), quercitrin ($IC_{50}=24.6\;{\mu}M$), quercetin ($IC_{50}=27.8\;{\mu}M$), (+)-dihydroquercetin ($IC_{50}=28.9\;{\mu}M$), and chlorogenic acid ($IC_{50}=30.6\;{\mu}M$) exhibited stronger antioxidant activity than L-ascorbic acid ($IC_{50}=31.5\;{\mu}M$) and ${\alpha}$-tocopherol ($IC_{50}=52.3\;{\mu}M$), whereas procatechuic acid ($IC_{50}=68.2\;{\mu}M$) showed lower activity. In addition, (+)-dihydrokaempferol ($IC_{50}=33.8\;{\mu}M$), trans-resveratrol ($IC_{50}=36.2\;{\mu}M$), moracin ($IC_{50}=47.6\;{\mu}M$), and 4-prenylmoracin ($IC_{50}=48.2\;{\mu}M$) exhibited moderate antioxidant activity. Furthermore, levels of the eleven polyphenolic compounds from three different types of mulberry seeds were quantified by HPLC, and their contents were as follows: rutin (311~60.0 mg/100 g)> quercitrin (7.2~34.2 mg/100 g)> (+)-dihydroquercetin (13.2~33.1 mg/100 g)> quercetin (15.8~19.5 mg/100 g)> 4-prenylmoracin (10.5~43.3 mg/100 g)> isoquercitrin (5.8~15.4 mg/100 g)> chlorogenic acid (0.0~15.3 mg/100 g)> moracin (4.7~7.2 mg/100 g)> procatechuic acid (0.0~11.6 mg/100 g)> (+)-dihydrokaempferol and trans-resveratrol (<0.1 mg/100 g). The 'Daesungppong' mulberry seeds among the three cultivars had higher flavonoid contents, such as rutin and quercetin derivatives, while the 'Iksuppong' seeds had the highest contents of phenolic acids and moracin derivatives. 'Cheongilppong' had lower amounts of polyphenolic compounds than the other two mulberry seeds. These results indicate that mulberry seeds containing antioxidant polyphenolic compounds may be potentially useful sources of anti-diabetic, anti-hypertensive, and anti-aging agents for functional foods and cosmetics.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2443-2446
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• 2012

• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.308-315
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• 2009

The activities of flower color biosynthesis-controlling enzymes, flavonoid 3'hydroxy lase (F3'H) and dihydroflavonol 4-reductase (DFR), were analyzed in Llium longijlorum and 11 lily cultivars using biochemical and enzymological methods. Dihydroquercetin (DHQ) product was synthesized by F3'H using dihydrokaempferol (DHK) as a substrate in Lilium longiflorum. F3'H activity was also detected in the eight cultivars tested. The substrate-specific activity of F3'H was observed because eridictiol (ERI), which uses naringenin (NAR) as a substrate, was not detected in the tested cultivars. Leucocyanidin (LCy) product was synthesized by DFR using DHQ as a substrate in Lilium longiflorum. DFR activity was also detected in 'Le Reve', 'Montreux', 'Monte Negro', 'Etude', 'Acapulco', and 'Star Gazer', but not in 'Siberia', 'Royal Race', 'Nove Cento', 'Elite', and 'Cannes'. Substrate-specific activity of DFR was observed because leucopelargonidin (LPg), which uses DHK as a substrate, was not detected in the tested cultivars.