• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.320-321
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• 2003

최근 천연물을 중심으로 한 학문이 발전하면서 천연물이 가지는 생리활성 물질에 대한 관심이 중대되고 있다. 또한 인공합성품의 일부가 안정성의 문제가 제기되면서 천연물의 이용분야는 더욱 확대되고 있다. 급속한 경제발전과 생활수준의 향상으로 식생활을 포함한 생활방식의 다양화로 인하여 과거 감염 위주의 질병이 감소하고 선진국형의 만성퇴행성 질환이 증가하는 추세이다. 혈소판은 혈전증(thrombosis)과 지혈증(haemstasis)에서 중요한 역할을 담당하고 있는 인자로서 현관 내 병적 이상으로 인한 과도한 혈전의 생성은 뇌 -심혈관계 질환의 중요한 유발인자로 작용하므로 뇌ㆍ심혈관계 질환이나 항고지혈증을 연구하는데 유용하게 이용되고 있다. 본 연구에서는 토끼 혈액에서 분리한 세정 혈소판 부유액을 이용하여 작약 MeOH 추출물에서 분리한 천연생리활성물질들을 대상으로 혈소판 응집억제활성에 대하여 연구하였다. 작약 MeOH 추출물의 혈소판 응집억제활성 측정에서 강한 혈소판 응집억제활성 작용을 보였다. 따라서 작약 MeOH 추출물을 크로마토그라피법을 이용하여 분리하였고, NMR을 이용한 분광학적 방법으로 지금까지의 분리한 자료와 비교ㆍ분석하였다. Monoterpene glycoside 계열의 성분들인 15개의 compound와 다수의 fraction들을 HPLC를 이용하여 분리하였으며, collagen으로 유도된 혈소판 응집억제활성측정 방법에서 뛰어난 응집억제활성을 보였다. 표준물질을 이용한 HPLC 분석과 ¹H-NMR 관련 자료의 검색을 통하여 최종적으로 compound 1b가 benzoyloxy-paeoniflorin(2.6％). compound 1d가 paeond(1.3％), compound 2c가 albiflorin(3.2％), compound 2e가 paeoniflorin(33.6％)임을 확인할 수 있었다. Compound 3a의 분석결과 benzoyloxypaeoniflorin과 구조적 유사성은 있으나 동일한 구조식으로 확인할 수 없었다. 그러나 collagen에서 응집억제활성이 90％ 이상으로 뛰어난 활성을 나타내므로 benzoyloxypaeoniflorin과 유사한 구조에서 benzoyl group이 다른 작용기로 치환되었거나 R₁ group이 다른 작용기로 치환된 형태로 추측하였다. Benzoyloxypaeoniflorin은 collagen＞thrombin＞U46616＞A.A(arachidonic acid)＞PAF의 순으로 활성을 보였다. 이는 paeoniflorin의 glycoside 5-carbon위치에 위치한 OH기 대신에 benzoyl기로 치환된 benzoyl 기가 혈소판 억제 산물로 작용한 것으로 추측했다. Paeoniflorin.은 U46619＞thrombin＞collagen＞A.A＞PAF순으로 억제를 보였다. Paeoniflorin이 collagen보다 thrombin에서 강한 억제를 보이는 것으로 Ca/sup 2＋/ chelate를 형성함으로 인해 calciu 대사를 저해하는 것으로 추축했다. Compound 3a는 U46619＞collagen＞A.A＞thrombin＞PAF순으로 억제율을 보이므로 이 화합물은 paeoniflorin의 benzoyl기에 OH기가 다른 치환기로 바뀌거나 paeoniflorin의 glycoside 5-carbon 위치의 OH기 대신에 다른 작용기로 치환된 것으로 추정하였다. 이러한 결과로 작약의 주성분인 paeoniflorin과 유사한 구조를 가진 다른 monoterpene glycoside 계열의 화합물들과 비교 분석하고 구조를 화인하고 이들 성분이 어떻게 혈소판 응집억제활성에 작용하는지를 연구하였다.

• Proceedings of the Korean Society of Tobacco Science Conference
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• 1997.10a
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• pp.134-152
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• 1997

Plant viruses of tobacco including tobacco mosaic virus (TMV) and potato virus Y (PVY) cause severe economic losses in leaf-tobacco production. Cultural practices do not provide sufficient control against the viruses. Use of valuable resistant cultivars is most recommendable for the control of the viruses. However, conventional breeding programs are not always proper for the development of virus-resistant plants mostly owing to the frequent lack of genetic sources and introduction of their unwanted properties. Therefore, we tried to develop virus-resistant tobacco plants by transforming commercial tobacco cultivars, NC 82 and Burley 21, with coat protein (CP) or replicase (Nlb) genes of TMV and PVY necrosis strain (PVY-VN) with or without untranslated region (UTR) and with or without mutation. Each cDNA was cloned and inserted in plant expression vectors with 1 or 2 CaMV 35S promotors, and introduced into tobacco leaf tissues by Agrobacterium tumefaciens LBA 4404. Plants were regenerated in kanamycin-containing MS media. Regenerated plants were tested for resistance to TMV and PVY In these studies, we could obtain a TMV-resistant transgenic line transformed with TMV CP and 6 genetic lines with PVY-VN cDNAs out of 8 CP and replicase genes. In this presentation, resistance rates, verification of gene introduction in resistant plants, stability of resistance through generations, characteristics of viral multiplication and translocation in resistant plants, and resistance responses relative to inoculum potential and to various PVY strains will be shown. Yield and quality of leaf tobacco of a promising resistant tobacco line will be presented.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.463-470
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• 2009

Sixteen antioxidative active compounds isolated from the EtOAc layer of MeOH extracts of kochujang, Korean fermented red pepper paste, were structurally elucidated as fumaric acid, methyl succinate, succinic acid furan-2-yl ester methyl ester (gochujangate, a novel compound), 2-hydroxy-3-phenylpropanoic acid, 3,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 6,7-dihydroxy-2H-chromen-2-one (esculetin), caffeic acid, cis-p-coumaric acid, trans-p-coumaric acid, daidzin, genistin, apigenin 7-O-$\beta$-D-apiofuranosyl($1{\rightarrow}2$)-$\beta$-D-glucopyranoside, apigenin 7-O-$\beta$-Dglucopyranoside, and quercetin 3-O-$\alpha$-L-rhamnopyranoside by mass spectrometry (MS) and nuclear magnetic resonance (NMR) experiments. These compounds were analyzed for the first time as antioxidants from kochujang.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1606-1614
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• 2023

Biochemical gut metabolism of dietary bioactive compounds is of great significance in elucidating health-related issues at the molecular level. In this study, a human gut bacterium cleaving C-C glycosidic bond was screened from puerarin conversion to daidzein, and a new, gram-positive C-glycoside-deglycosylating strain, Dorea sp. MRG-IFC3, was isolated from human fecal sample under anaerobic conditions. Though MRG-IFC3 biotransformed isoflavone C-glycoside, it could not metabolize other C-glycosides, such as vitexin, bergenin, and aloin. As evident from the production of the corresponding aglycons from various 7-O-glucosides, MRG-IFC3 strain also showed 7-O-glycoside cleavage activity; however, flavone 3-O-glucoside icariside II was not metabolized. In addition, for mechanism study, C-glycosyl bond cleavage of puerarin by MRG-IFC3 strain was performed in D₂O GAM medium. The complete deuterium enrichment on C-8 position of daidzein was confirmed by ¹H NMR spectroscopy, and the result clearly proved for the first time that daidzein is produced from puerarin. Two possible reaction intermediates, the quinoids and 8-dehydrodaidzein anion, were proposed for the production of daidzein-8d. These results will provide the basis for the mechanism study of stable C-glycosidic bond cleavage at the molecular level.

• Natural Product Sciences
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• v.27 no.4
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• pp.245-250
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• 2021

The methylglyoxal (MGO) trapping constituents from Malus baccata L. were investigated using incubation of MGO and crude extract under physiological conditions followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Sieboldin was identified as a major active molecule representing MGO-trapping activity of the crude extract. After reaction of sieboldin and MGO, remaining MGO was calculated by microplate assay method using imine (Schiff base) formation of 2,4-dinitrophenylhydrazine (DNPH) and aldehyde group. After 4 h incubation, sieboldin trapped over 43.8% MGO at a concentration of 0.33 mM and showed MGO scavenging activity with an RC₅₀ value of 0.88 mM for the incubation of 30 min under physiological conditions. It was also confirmed that sieboldin inhibited the production of advanced glycation end products (AGE) produced by bovine serum albumins (BSA)/MGO. Additionally, MGO trapping mechanism of sieboldin was more specifically identified by ¹H-, ¹³C-, 2D NMR and, confirm to be attached to the position of C-3' (or 5').

• Macromolecular Research
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• v.17 no.10
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• pp.739-745
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• 2009

N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-g were synthesized by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 1 with two equimolars of Lalanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e, L-2-aminobutyric acid 2f and L-histidine 2g in an acetic acid solution. Seven new poly(amide-imide)s PAIs 5a-g were synthesized through the direct polycondensation reaction of seven chiral N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-g with bis(3-amino phenyl) phenyl phosphine oxide 4 by two different methods: direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride ($CaCl_2$/pyridine (py), and direct polycondensation in a tosyl chloride (TsCl)/pyridine (py)/N,N-dimethylformamide (DMF) system. The polymerization reaction produced a series of flame-retardant and thermally stable poly(amide-imide)s 5a-g with high yield. The resulted polymers were fully characterized by FTIR, $^1H$ NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation and solubility tests. Data obtained by thermal analysis (TGA and DTG) revealed that the good thermal stability of these polymers. These polymers can be potentially utilized in flame retardant thermoplastic materials.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.806-822
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• 2023

In the current study we assessed a new crystallized compound, 5-(1-hydroxybutyl)-4-methoxy-3-methyl-2H-pyran-2-one (C-HMMP), from the endophytic fungus Colletotrichum acutatum residing in the medicinal plant Angelica sinensis for its in vitro antimicrobial, antibiofilm, antioxidant, antimalarial, and anti-proliferative properties. The promising compound was identified as C-HMMP through antimicrobial-guided fraction. The structure of C-HMMP was unambiguously confirmed by 2D NMR and HIRS spectroscopic analysis. Antimicrobial property testing of C-HMMP showed it to be effective against a variety of pathogenic bacteria and fungi with MICs ranging from 3.9 to 31.25 ㎍/ml. The compound displayed excellent antibiofilm activity against C. albicans, S. aureus, and K. pneumonia. Furthermore, the antimalarial and radical scavenging activities of C-HMMP were clearly dosedependent, with IC50 values of 0.15 and 131.2 ㎍/ml. The anti-proliferative activity of C-HMMP against the HepG-2, HeLa, and MCF-7 cell lines in vitro was investigated by MTT assay, revealing notable anti-proliferative activity with IC50 values of 114.1, 90, and 133.6 ㎍/ml, respectively. Moreover, CHMMP successfully targets topoisomerase I and demonstrated beneficial anti-mutagenicity in the Ames test against the reactive carcinogenic mutagen, 2-aminofluorene (2-AF). Finally, the compound inhibited the activity of α-glucosidase and α-amylase with IC50 values of 144.7 and 118.6 ㎍/ml, respectively. To the best of our knowledge, the identified compound C-HMMP was obtained for the first time from C. acutatum of A. sinensis, and this study demonstrated that C-HMMP has relevant biological significance and could provide better therapeutic targets against disease.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.63-66
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• 2011

The bark of Machilus thunbergii was extracted with 80% aqueous methanol (MeOH), and the concentrated extract was partitioned using ethyl acetate (EtOAc), butanol (n-BuOH), and $H_2O$, successively. From the EtOAc fraction, five lignans were isolated through the repeated silica gel, octadecyl silica gel (ODS) and, Sephadex LH-20 column chromatography. Based on nuclear magnetic resonance (NMR), mass spectroscopy (MS), and infrared spectroscopy (IR) spectroscopic data, the chemical structures of the compounds were determined to be machilin A (1), machilin F (2), licarin A (3), nectandrin A (4), and nectandrin B, (5). This study presents comparative account of five lignans from M. thunbergii bark contributing inhibition of low density lipoprotein (LDL), ACAT-1, and ACAT-2. Compounds 2-5 showed varied degree of antioxidant activity on LDL with $IC_{50}$ values of 2.1, 11.8, 15.3, and $4.1{\mu}M$. Compounds 1, 2, and 3 showed inhibition activity on ACAT-1 with values $63.4{\pm}6.9%$ ($IC_{50}=66.8{\mu}M$), $53.7{\pm}0.9%$ ($IC_{50}=109.2{\mu}M$), and $78.7{\pm}0.2%$ ($IC_{50}=40.6{\mu}M$), respectively, at a concentration of 50 mg/mL, and on ACAT-2 with values $47.3{\pm}1.5%$ ($IC_{50}=149.7{\mu}M$), $39.2{\pm}0.2%$ ($IC_{50}=165.2{\mu}M$), and $52.1{\pm}1.0%$ ($IC_{50}=131.0{\mu}M$, respectively, at a concentration of 50 mg/mL.

• Korean Journal of Medicinal Crop Science
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• v.7 no.1
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• pp.51-57
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• 1999

To search for antioxidative compounds from plant resources, methanol extracts of 45 plant species were investigated using DPPH method. The highest activity was shown in the methanol extract of Acer ginnala($RC_{50}\;:\;15{\mu}g$), followed by Stewartia koreana($RC_{50}\;:\;28{\mu}g$) and Carpinus laxiflora($RC_{50}\;:\;33{\mu}g$). Two antioxidative compounds were isolated from the methanolic extract of Acer ginnala Max and identified as acertannin(2, 6-di-O-galloyl-1, 5-anhydro-D-glucitol) and gallicin (methyl-3, 4, 5-trihydroxybenzoic acid) on the basis of mass spectroscopy, $^1H-\;and\;^{13}C-NMR$ data. The DPPH free radical scavenging activities of acertannin($RC_{50}\;:\;3.5{\mu}g$) and gallicin($RC_{50}\;:\;2.8{\mu}g$) were more effective than those of BHA($RC_{50}\;:\;14{\mu}g$) and ${\alpha}-tocopherol$ ($RC_{50}\;:\;12{\mu}g$).

• Journal of Life Science
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• v.20 no.3
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• pp.430-436
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• 2010

In this study, the effects of dibenzocyclooctadiene on seed germination were investigated in pepper. Four $C_{18}$ dibenzocyclooctadiene lignans - schisandrin (1143.7 mg), schisandrin C (317.3 mg), gomisin A (261.4 mg) and gomisin N (213.4 mg) - were isolated from hexane extracts of the fruits of Schisandra chinensis. The molecular structures of the four lignans were elucidated based on spectroscopic analyses including 1D NMR experiments, and bi comparing their spectroscopic data with those of previous literatures. Seeds were immersed in $10^{-5}\;M$ schisandrin, $10^{-6}\;M$ schisandrin C and $10^{-7}\;M$ gomisin A and gomisin N for 1 hr and incubated at $25^{\circ}C$ in the dark for germination. Compared to untreated control, treatment with schisandrin C and gomisin A suppressed seed germination at 48 hrs after incubation, whereas treatment with gomisin N increased germination rate at 48 hrs after incubation. The results of the germination activity of the lignans from S. chinensis confirm their potential plant growth role, and the relative natural abundances of these metabolites suggest their potential use as natural plant growth regulators.