• Natural Product Sciences
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• 제21권3호
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• pp.176-184
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• 2015

In our search for natural soluble epoxide hydrolase (sEH) inhibitors from plants, an extract of the dried whole plants of Euphorbia supina Rafin was found to significantly inhibit sEH activity in vitro. Phytochemical investigation of E. supina resulted in isolation of 17 compounds (1 - 17), including triterpenes (1 - 4), phenolic compounds (5 - 8), and flavonoid derivatives (9 - 17). The structures of the isolated compounds were established mainly by extensive analysis of the 1D and 2D NMR, and MS data. All of the isolated compounds were evaluated for their sEH inhibitory activity. Among the isolated phenolic compounds, 8 was identified as a significant inhibitor of sEH, with an IC₅₀ value of 15.4 ± 1.3 μM. Additionally, a kinetic analysis of isolated compounds (2, 5, 8 - 11, 13, and 17) indicated that the inhibitory effects of flavonoid derivatives 10 and 11 were of mixed-type, with inhibitory constants (K_i) ranging from 3.6 ± 0.8 to 21.8 ± 1.0 μM, whereas compounds 2, 5, 8, 9, 13, and 17 were non-competitive inhibitors with inhibition K_i values ranging from 3.3 ± 0.2 to 39.5 ± 0.0 μM.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1859-1864
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• 2018

Synthesis of flavonoid glycoside is difficult due to diverse hydroxy groups in flavonoids and sugars. As such, enzymatic synthesis or biotransformation is an approach to solve this problem. In this report, we used stepwise biotransformation to synthesize two quercetin bisglycosides (quercetin 3-O-glucuronic acid 7-O-rhamnoside [Q-GR] and quercetin 3-O-arabinose 7-O-rhamnoside [Q-AR]) because quercetin O-rhamnosides contain antiviral activity. Two sequential enzymatic reactions were required to synthesize these flavonoid glycosides. We first synthesized quercetin 3-O-glucuronic acid [Q-G], and quercetin 3-O-arabinose [Q-A] from quercetin using E. coli harboring specific uridine diphopsphate glycosyltransferase (UGT) and genes for UDP-glucuronic acid and UDP-arabinose, respectively. With each quercetin 3-O-glycoside, rhamnosylation using E. coli harboring UGT and the gene for UDP-rhamnose was conducted. This approach resulted in the production of 44.8 mg/l Q-GR and 45.1 mg/l Q-AR. This stepwise synthesis could be applicable to synthesize various natural product derivatives in case that the final yield of product was low due to the multistep reaction in one cell or when sequential synthesis is necessary in order to reduce the synthesis of byproducts.

• Archives of Pharmacal Research
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• 제27권9호
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• pp.937-943
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• 2004

Recent investigations have shown that certain flavonoids, especially flavone derivatives, inhibit nitric oxide (NO) production by inducible NO synthase (iNOS) in macrophages, which contrib-ute their anti-inflammatory action. For the purpose of finding the optimized chemical structures of flavonoids that inhibit NO production, various A- and B-ring substituted flavones were syn-thesized and evaluated for their inhibitory activity using lipopolysaccharide-treated RAW 264.7 cells. It was found that the optimal chemical structures were A-ring 5,7-dihydroxyflavones hav-ing the B-ring 2＇,3＇-dihydroxy or 3＇,4＇-dihydroxy or 3＇,4＇-hydroxy/methoxy (methoxy/hydroxy) groups. These structurally optimized compounds were revealed to be down-regulators of iNOS induction, but not direct iNOS inhibitors. Of these derivatives that were evaluated, 2＇,3＇,5,7-tet-rahydroxyflavone and 3＇,4＇,5,7-tetrahydroxyflavone (Iuteolin) showed the strongest inhibition. The $IC_{50}$/ values for these compounds were 19.7 and 17.1 11M, respectively. Therefore, these compounds may have a potential as new anti-inflammatory agents.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1317-1328
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• 2023

Green tea (GT) polyphenols undergo extensive metabolism within gastrointestinal tract (GIT), where their derivatives compounds potentially modulate the gut microbiome. This biotransformation process involves a cascade of exclusive gut microbial enzymes which chemically modify the GT polyphenols influencing both their bioactivity and bioavailability in host. Herein, we examined the in vitro interactions between 37 different human gut microbiota and the GT polyphenols. UHPLC-LTQ-Orbitrap-MS/MS analysis of the culture broth extracts unravel that genera Adlercreutzia, Eggerthella and Lactiplantibacillus plantarum KACC11451 promoted C-ring opening reaction in GT catechins. In addition, L. plantarum also hydrolyzed catechin galloyl esters to produce gallic acid and pyrogallol, and also converted flavonoid glycosides to their aglycone derivatives. Biotransformation of GT polyphenols into derivative compounds enhanced their antioxidant bioactivities in culture broth extracts. Considering the effects of GT polyphenols on specific growth rates of gut bacteria, we noted that GT polyphenols and their derivate compounds inhibited most species in phylum Actinobacteria, Bacteroides, and Firmicutes except genus Lactobacillus. The present study delineates the likely mechanisms involved in the metabolism and bioavailability of GT polyphenols upon exposure to gut microbiota. Further, widening this workflow to understand the metabolism of various other dietary polyphenols can unravel their biotransformation mechanisms and associated functions in human GIT.

• 한국환경생태학회지
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• 제28권5호
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• pp.574-587
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• 2014

본 연구에서는 우리나라 신갈나무(Quercus mongolica Fisch. ex Ledeb.)와 졸참나무(Q. serrata Murray) 두 종의 수직분포 양상을 관찰하고, 지리산 지역을 중심으로 두 종간의 교잡이입 및 유전자 전달 가능성을 식물화학적 분석을 통해 추론하고자 하였다. 우리나라의 신갈나무와 졸참나무의 수직분포는 위도에 따라 지역 간 차이가 난다. 중부지방에서는 신갈나무가 해발 100~200m의 낮은 고도에서부터 고재대에 이르기까지 널리 분포하나 남부지방의 경우 일반적으로 해발 300m 이하 저지대에서는 거의 분포하지 않으며, 졸참나무는 중부지방의 경우 저지대에서 주로 관찰되며 해발 500~700m이상에서는 거의 발견되지 않으나 남부지방의 경우 해발 1,000m이상에서도 관찰된다. 두 종은 분포대가 달라 신갈나무는 주로 높은 해발고도에서 졸참나무는 주로 낮은 해발고도에서 생육하나, 상당한 범위의 고도 구간에서 두 종은 혼생한다. 지리산 지역을 위주로 설악산, 소백산, 마니산 등에서 채집된 신갈나무와 졸참나무의 잎 플라보노이드 성분을 분석한 결과, 2종 37개체로부터 총 23종류의 서로 다른 화합물이 분리, 동정되었다. 이들 플라보노이드 화합물은 flavonol인 kaempferol, quercetin, myricetin 및 isorhamnetin에 당이 결합된 flavonol glycoside이었으며, 4 종류의 acylated flavonoid compound가 동정되었다. 이들 중 kaempferol 3-O-glucoside, quercetin 3-O-glucoside와 quercetin 3-O-galactoside 및 이들의 acylated compounds가 주요 성분으로 두 종의 모든 개체에서 나타났다. 신갈나무의 플라보노이드 조성은 졸참나무에서는 나타나지 않는 diglycoside인 quercetin 3-O-arabinosylglucoside가 분포하며, acylated compound인 acylated kaempferol 3-O-glucoside, acylated quercetin 3-O-galactoside 및 acylated quercetin 3-O-glucoside가 다량 분포한다는 점에서 졸참나무의 flavonoid 조성과 구분된다. 졸참나무의 flavonoid 조성은 3개의 rhamnosyl flavonol compounds가 전체 졸참나무 개체에 걸쳐서 나타나며 또한 신갈나무에 비해 다량으로 나타나고, diglycoside인 kaempferol 3-O-rhamnosylglucoside를 함유하는 특징을 갖는다. 두 종 개체들의 flavonoid 조성은 고도에 따라 종내 개체 간 변이가 있었으며, 동소적으로 분포하는 두 종의 개체들은 대체로 상대 종의 플라보노이드 조성을 정량적으로 또는 정성적으로 닮는 경향이 있었다. 이러한 사실은 지리산 지역에서 두 종간에 교잡이입을 통한 유전자 교환이 일어나고 있음을 강하게 암시한다. 이와 같은 상호 교배 및 교잡이입 가능성으로 볼 때, 형태적으로 신갈나무와 졸참나무의 중간적인 특징을 나타내는 물참나무는 두 종을 부모종으로 하는 교잡에 의해 생긴 잡종분류군일 가능성이 높은 것으로 사료된다.

• 생명과학회지
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• 제24권10호
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• pp.1092-1101
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• 2014

본 연구에서는 우리나라 설악산 지역을 중심으로 신갈나무와 졸참나무 두 종의 수직분포 양상을 관찰하고, 두 종간의 교잡이입 및 유전자 전달 가능성을 플라보노이드 분석을 통해 추론하고자 하였다. 중부지방인 설악산의 신갈나무와 졸참나무의 수직분포는 남부지방인 지리산에서와는 차이가 난다. 설악산의 경우, 해발 100 m 이상 거의 전 고도에서 신갈나무가 나타나나 졸참나무는 해발 500 m 이상에서는 드물게 나타나며 500 m 이하에서 신갈나무와 혼생한다. 지리산의 경우, 졸참나무의 수직 분포 범위는 해발 0-1,200 m로 설악산에 비해 훨씬 넓으며, 신갈나무는 높은 해발고도에서는 순림을 이루지만 해발 1,000 m 이하에서는 고도가 낮아질수록 빈도가 낮아지고 해발 300 m 이하에서는 거의 분포하지 않는다. 전반적으로 우리나라에서 신갈나무는 높은 고도에서, 졸참나무는 낮은 고도에서 생육하나 상당한 범위의 고도 구간에서 두 종은 혼생한다. 설악산 지역의 신갈나무와 졸참나무 32개체와 지리산 고지대 및 저지대에 분포하는 신갈나무, 졸참나무 각 1개체 등 총 34개체를 대상으로 잎의 플라보노이드 성분을 분석한 결과, 이들로부터 총 24종류의 서로 다른 화합물이 분리, 동정되었다. 이들 플라보노이드 화합물은 모두 flavonol인 kaempferol, quercetin, myricetin 및 isorhamnetin에 당이 결합된 flavonol glycoside이었으며, 이 중 5개는 acylated flavonoid compound이다. 이들 중 kaempferol 3-O-glucoside, quercetin 3-O-glucoside와 quercetin 3-O-galactoside 및 이들의 acylated compounds가 주요 성분으로 두 종의 모든 개체에서 나타났다. 신갈나무의 플라보노이드 조성은 acylated kaempferol 3-O-glucoside, acylated quercetin 3-O-galactoside 및 acylated quercetin 3-O-glucoside가 다량 나타나고, 졸참나무에서는 나타나지 않는 diglycoside인 quercetin 3-O-arabinosylglucoside가 분포하는 특징을 가진다. 졸참나무의 flavonoid 조성은 3개의 rhamnosyl flavonol compounds가 전체 졸참나무 개체에 걸쳐서 나타나고 또한 이들 compound가 신갈나무에 비해 다량으로 나타나는 특징을 갖는다. 신갈나무와 졸참나무 두 종간에는 이러한 정량 정성적인 플라보노이드 조성 차이와 함께 소량으로 분포하는 몇몇 compound들에 있어서 정성적인 차이도 나타나 두 종은 플라보노이드 조성에 있어 뚜렷이 구분된다. 한편, 두 종의 플라보노이드 조성은 고도에 따라 종내 개체 간 변이가 있으며, 동소적으로 분포하는 두 종 개체들의 플라보노이드 조성은 대체로 정량적 또는 정성적으로 상대 종의 플라보노이드 조성을 닮는 경향이 있었다. 이러한 현상은 두 종간에 교잡이입을 통한 유전자 교환이 일어나고 있음을 강하게 암시한다.

• Journal of Ginseng Research
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• 제47권4호
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• pp.593-603
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• 2023

Background: Korean Red Ginseng is a major source of bioactive substances such as ginsenosides. Efficacy of red ginseng extract (RGE), which contains not only saponins but also various non-saponins, has long been studied. In the water-soluble component-rich fraction of RGE (WS), a byproduct generated in the process of extracting saponins from the RGE, we identified previously unidentified molecules and confirmed their efficacy. Methods: The RGE was prepared and used to produce WS, whose components were isolated sequentially according to their water affinity. The new compounds from WS were fractionized and structurally analyzed using nuclear magnetic resonance spectroscopy. Physiological applicability was evaluated by verifying the antioxidant and anti-inflammatory efficacies of these compounds in vitro. Results: High-performance liquid chromatography confirmed that the obtained WS comprised 11 phenolic acid and flavonoid substances. Among four major compounds from fractions 1-4 (F1-4) of WS, two compounds from F3 and F4 were newly identified in red ginseng. The analysis results show that these compound molecules are member of the maltol-structure-based glucopyranose series, and F1 and F4 are particularly effective for decreasing oxidative stress levels and inhibiting nitric oxide secretion, interleukin (IL)-1β and IL-6, and tumor necrosis factor-α. Conclusion: Our findings suggest that a few newly identified maltol derivatives, such as red ginseng-derived non-saponin in the WS, exhibit antioxidant and anti-inflammatory effects, making them viable candidates for application to pharmaceutical, cosmetic, and functional food materials.

• 한국염색가공학회지
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• 제13권5호
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• pp.306-311
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• 2001

Natural colorants haute attracted much attention all over the world because of their non-hazardous nature. The world is becoming increasingly aware of environmental Issues, such as ozone layer depletion, water pollution and waste disposal problems. The use of synthetic dyestuffs for their synthesis and application in the dyeing industries has been criticized due to introduction of contaminants into the environment. This has led to the desire to turn to the traditional, and more natural way of life. In this study, the colorants of extract of Ginkgo biloba bark were analysed and their dyeing properties on silk, wool and cotton were studied. It was found that uv-visible absorption spectra of extract of Ginkgo biloba bark showed two strong absorption Peaks in the range of 240 ∼400 In. From the result of IR spectra, the major ingredient of extract of Gikgo biloba bark seems to be the flavon which is one of the flavonoid derivatives. Silk, wool, and cotton dyed with the extract of Ginkgo biloba bark showed a reddish yellow color. Their color differences were increased drastically with repetition of dyeing by three times.

• Natural Product Sciences
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• 제12권3호
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• pp.125-128
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• 2006

A chemical examination of the stems of Sapium japonicum PAX et $H_{OFFM}$ (Euphorbiaceae) has led to the isolation of seven phenolic compounds. On the basis of UV, IR, MS, and NMR spectral data and the chemical reaction, the structures of these compounds were identified as gallic acid (1), ellagic acid (2), 3,3'-di-O-methylellagic acid (3), $4-O-({\beta}-D-xylopyranosyl)-3,3'-di-O-methylellagic$ acid (4), $4-O-({\alpha}-D-arabinofuranosyl)-3,3'-di-O-methylellagic$ acid (5), isoquercitrin (6), and geraniin (7).

• 생약학회지
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• 제43권3호
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• pp.201-205
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• 2012

In the course of screening pancreatic lipase inhibitory activity, total methanolic extract and EtOAc-soluble fraction of Duchesnea chrysantha showed significant inhibitory activity. Further fractionation and isolation of the EtOAc-soluble fraction resulted in five compounds, which were identified as trans-tiliroside (1), isovitexin (2), kaempferol-8-O-${\beta}$-glucoside (3), kaempferol-3-O-${\beta}$-glucoside (4) and quercetin-3-O-${\beta}$-glucoside (5). All the five flavonoids derivatives were first reported from this plant but showed weak inhibitory effects on pancreatic lipase activity.