• 한국식품영양과학회지
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• 제24권6호
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• pp.901-905
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• 1995

기호음료 및 약용으로 사용되는 두충나무잎의 품질 평가를 위한 HPLC로서 함유된 flavonoid 화합물을 정성, 정량 분석하였다. 즉 두충나무잎의 n-BuOH 분획으로 부터 astragalin, isoquercitrin, quercetin $3-O-{\beta}-D-xylopyranosyl(1-2)-{\beta}-D-glucopyranoside$의 3종 flavonoid 성분들을 분리하였으며, 이들 화합물은 LPLC의 THF-dioxane-MeOH-HOAc-5% $H_3PO_4-H_2O$(145 : 125 : 50 : 20 : 2 : 658) 혼합용매에서 양호한 분리능을 나타내었다. MeOH 엑스와 n-BuOH 분획 중에 astragaline의 함량은 각각 0.09%(w/w), 0.46%(w/w), isoquercitrin은 0.08%(w/w), 0.48(w/w), quercetin $3-O-{\beta}-D-xylopyranosyl(1-2)-{\beta}-D-glucopyranoside$은 0.40%(w/w), 1.22%(w/w) 함유되어있다.

• Journal of Applied Biological Chemistry
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• 제61권4호
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• pp.321-325
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• 2018

본 연구에서는 어리연꽃에서 분리된 isoquercitrin (IQC)를 이용하여 ROS 활성 억제, procollagen 합성유도, MMP-1의 발현억제를 측정함으로써 주름개선 기능성 화장품 원료로서의 가능성을 평가하였다. 그 결과, ROS는 농도의존적으로 억제하는 경향을 나타내었고 procollagen protein 합성증가율은 대조군과 비교하여 70% ($5{\mu}g/mL$), MMP-1 protein은 41% ($5{\mu}g/mL$)의 억제 활성을 보여주었다. 이것으로 IQC의 procollagen 합성유도능과 ROS 및 MMP-1의 강력한 저해효과를 확인 할 수 있었다. 따라서 어리연꽃에서 분리된 IQC는 기능성 화장품 소재로 할 충분한 가치가 있다고 사료된다.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1521-1530
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• 2023

An α-L-rhamnosidase gene from Thermoclostridium. stercorarium subsp. thermolacticum DSM 2910 (TstRhaA) was cloned and expressed. The maximum TstRhaA activity of the protein reached 25.2 U/ml, and the molecular mass was approximately 106.6 kDa. The protein was purified 8.0-fold by Ni-TED affinity with an overall recovery of 16.6% and a specific activity of 187.9 U/mg. TstRhaA activity was the highest at 65℃ and pH 6.5. In addition, it exhibited excellent thermal stability, better pH stability, good tolerance to low concentrations of organic reagents, and high catalytic activity for p-nitrophenyl-α-L-rhamnopyranoside (pNPR). Substrate specificity studies showed that TstRhaA exhibited a high specific activity for rutin. At 60℃, pH 6.5, and 0.3 U/ml enzyme dosage, 60 g/l rutin was converted to 45.55 g/l isoquercitrin within 150 min. The molar conversion rate of rutin and the yield of isoquercitrin were 99.8% and 12.22 g/l/h, respectively. The results suggested that TstRhaA could be used for mass production of isoquercitrin.

• 생약학회지
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• 제30권2호
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• pp.196-201
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• 1999

Four antioxidative flavonoids were isolated from the aerial parts of Hypericum erectum. Their structures were identified as quercitrin (I), isoquercitrin (Ⅱ), hyperoside (Ⅲ) and orientin (IV) on the basis of spectroscopic means. Antioxidative activities for flavonoids $I{\sim}IV$ were determined by measuring lipid peroxide using 2-thiobarbituric acid (TBA) method and by evaluation the radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Compound IV, orientin, was found to have strong antioxidative potency.

• 생약학회지
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• 제27권1호
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• pp.1-5
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• 1996

Twelve compounds were isolated from stems of Securinega suffruticosa. On the basis of chemical and spectroscopic evidence, they were identified as gallic acid, corilagin, tercatain, geraniin, bergenin, norbergenin, 4-O-galloylnorberg-enin, 11-O-galloylnorbergenin, (+)-catechin, gallocatechin, isoquercitrin and rutin.

• Archives of Pharmacal Research
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• 제15권4호
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• pp.365-370
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• 1992

Seven flavonoids were isolated from the aerial parts of Lonicera japonica. Their structures were characterized as hydnocarpin 1, quercetin 2, ochnaflavone 3, ochnaflavone 4'-O-methylether 4, astragalin 5, isoquercitrin 6, and rhoifolin 7 by chemical and spectroscopic evidences.

• 생약학회지
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• 제29권3호
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• pp.225-230
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• 1998

Cornus controversa $H_{EMSL}$. (Cornaceae) is distributed widely in Korea and has been used for the treatment of diarrhea and a tonic medicine. Six compounds were isolated from the MeOH extract of the dried stem bark of Cornus controversa. Their structures were identified as gallic acid(1), scopoletin(2), arjunglucoside II(3), isoquercitrin(4), quercitrin(5) and rutin(6) by comparisons of the physicochemical and spectroscopic evidences. Among these compounds, scopoletin and arjunglucoside II were the first time isolation from this plant.

• 생약학회지
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• 제29권3호
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• pp.217-224
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• 1998

Eight compounds were isolated from the stem bark of Cornus walteri. On the basis of chemical and spectroscopic evidences, the structures of these compounds were identified as gallic acid, (+)-gallocatechin, (+)-catechin, quercetin, quercitrin, rutin, isoquercitrin and hyperoside respectively.

• 한국약용작물학회지
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• 제2권1호
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• pp.67-72
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• 1994

어린잎을 식용으로 하고 전초를 차전엽산자고라 하여 강장약 및 진해제로 사용되는 얼레지(Ery-thronium japonicum)의 잎의 성분 연구에 착수하여 phtalate ester인 di -0-n-decylphthalate,fla-vonol인 kaempferol 및 quercetin, 그리고 그들의glucoside인 astragalin및 isoquercitrin의 구조를 동정하였다.

• Archives of Pharmacal Research
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• 제25권4호
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• pp.449-452
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• 2002

The antioxidant activity of Juniperus chinensis (Cupressaceae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of J. chinensis heartwood showed the strong antioxidant activity. The antioxidant activity of n-BuOH soluble fraction was stronger than that of the others, and the fraction was subjected to purification by repeated silica gel and Sephadex LH-20 column chromatography. Quercetin, naringenin, taxifolin, aromadendrin and isoquercitrin were isolated from the n-BuOH fraction. Their structures were elucidated by physico-chemical and spectroscopic studies.