• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.217.1-217.1
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• 2010

본 연구에서는 실제 천연가스 구성성분인 메탄 (90%)+에탄 (7%)+프로판 (3%) 혼합기체를 사용하여 심해저 퇴적부에 존재하는 천연가스 하이드레이트 개발과 가스 하이드레이트 형성법을 이용한 천연가스 수송 및 저장법 개발을 위한 열역학적 특성을 살펴보았다. 천연가스 하이드레이트 개발 연구에서는 심해저 퇴적층의 영향을 살펴보기 위해 기공의 직경이 6.0, 15.0, 30.0, 100.0 nm인 다공성 실리카 젤을 사용하여 기공 직경에 따른 3상(하이드레이트 (H)-물 (LW)-기상 (V)) 평형을 측정하였다. 천연가스 하이드레이트 수송/저장법 연구에서는 천연가스 하이드레이트 형성 압력을 낮추어 줄 수 있는 열역학적 촉진제인 TBAB(농도: 5, 10, 40, 60 wt%)와 THF(농도: 1, 5.56, 10 mol%)를 첨가하여 각각의 농도에 따른 혼합 가스 하이드레이트의 3상 평형을 측정하였다. 그 결과 다공성 매질인 실리카 젤의 경우 기공 직경의 크기가 작아질수록 벌크상태의 하이드레이트에 비해 평형 온도는 낮아지고, 평형 압력은 높아져 저해효과가 커짐을 알 수 있었고, 열역학적 촉진제를 첨가했을 경우 TBAB의 농도가 40 wt%, THF의 농도가 5.56 mol%일 경우 촉진 정도가 가장 크게 나타났으며, 그 이상의 농도일 경우 가스 하이드레이트 형성 반응에 참여하지 않은 TBAB와 THF에 의해 오히려 촉진 정도가 감소하는 것을 알 수 있었다. 또한 $^{13}C$ NMR 분석을 통해 혼합 가스 하이드레이트의 격자 형성과 기체 포집에 따른 구조적인 변화에 대해서도 살펴보았다.

• Natural Product Sciences
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• 제27권3호
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• pp.176-182
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• 2021

The phytochemical investigation of Broussonetia kazinoki roots led to the isolation of ten compounds, including six flavonoids (1-6), two lignans (7 and 8), and two coumarins (9 and 10) by comparing their ¹H and ¹³C NMR spectra with reference values. To the best of our knowledge, compounds 9 and 10 were isolated from this plant for the first time. Among the ten isolates, compounds 2, 4, and 6 exhibited inhibitory effects against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophage RAW264.7 cells with IC₅₀ values of 11.98, 10.16, and 24.06 μM, respectively. Furthermore, compounds 2, 4, and 6 reduced LPS-induced inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner. Pre-incubation of cells with these compounds also significantly suppressed LPS-induced COX-2 protein expression. Compounds 2, 4, and 6 also showed cytotoxic activity against HL-60 cells with IC₅₀ values ranging between 46.43 and 94.06 μM.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.82-86
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• 1996

Three thousand microbial strains collected from different sources were screened for herbicidal activity. A strain of ME-9189 showed herbicidal activity against Digitaria sanguinalis and Portulaca oleracea was isolated from a mountainy soil. Based on taxonomic studies, the strain was identified as Streptomyces tubercidicus. The active compound of ME-9189 was purified from the culture broth by charcoal, silica gel, sephadex LH-20 column chromatography and crystalization, consecutively. The ME-9189 compound was identified as tubercidin by spectroscopic methods of UV, $^{1}H$ and $^{13}C$-NMR, and EIMS. In the bioassay, growth of radish shoot and root was inhibited by 50% with tubercidin treatment of 10 ppm, showing 2 times higher activity than that of herbicidin A and similar to that of toyocamycin.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.798-803
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• 1999

Prolyl endopeptidase [PEP; EC 3.4.21.26], a serine protease which is known to cleave peptide bonds on the carboxy side of a proline residue, plays an important role in the degradation of proline-containing neuropeptides that have been suggested to participate in learning and memory processes. An abnormal increase in the level of PEP, which can lead to generation of $A{\beta}$, is also suggested to be involved in Alzheimer's type senile dementia. In the course of screening PEP inhibitors from Basidiomycetes, the mushroom Polyozellus multiplex exhibited a high inhibitory activity against PEP. Two active compounds were isolated from the ethyl acetate soluble fraction by consecutive purification, using silica gel, Sephadex LH-20, and Lobar RP-18 chromatography. The chemical structures of these compounds were identified as thelephoric acid and 12-acety1-2,3,7,8-tetrahydroxy-[12H]-12-hydroxymethylbenzobis[I.2b,3.4b'] benzofuran-11-one (kynapcin-9) by spectral data including UV, IR, MS, HR-MS, $^1H-,{\;}^{13}C-$, and 2D-NMR. The $IC_{50}$ values of the thelephoric acid and kynapcin-9 were 0.157 ppm (446nM) and 0.087 ppm (212nM) and their inhibitor constants ($K_i$) were 0.73ppm ($2.09{\;}\mu\textrm{m}$) and 0.060 ppm (146 nM), respectively. Furthermore, they were non-competitive with a substrate in Dixon plots.

• 한국작물학회지
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• 제37권4호
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• pp.377-382
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• 1992

본 연구는 고항산화 양질 육종의 체계확립을 위해서 참깨에 있는 특수성분인 sesamin, sesamolin의 표준물질을 동정하고 그 분석기술을 개발하였는바 그 결과는 다음과 같다. 1. 한국산 참깨로부터 sesamin, sesamolin 성분을 분리하여 화학적 구조를 분광학적 방법(UV, $^1$H와 $^{13}$C-NMR, MS)으로 확인하여 sesamin, sesamolin의 표준물질을 동정하였다. 2. 참깨 lignan성분의 추출 및 분리에는 Unsaponifiable fration 보다 MeOH 냉온처리가 더 효과적이었다. 3. 검량선의 회귀직선의 방정식은 sesamin에서 y=53924.43＋1277.93x(r=0.9993)이었고 sesamolin의 경우는 y=11034.95＋1188.38x(r=0.9994)로 추정되었다. 4. 한국산 참깨의 lignan 성분함량은 단백깨의 경우 sesamin 0.42% sesamolin 0.3%로 나타났다.

• 대한화학회지
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• 제33권4호
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• pp.366-370
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• 1989

새로운 거대고리 리간드 1,15,18-triaza-3,4 : 12,13-dibenzo-5,8,11-trioxa-cycloeicosane(NdienOdien$H_4$=$N_3O_3$)를 합성하여 $25^{\circ}C$ 95% 메탄올 용액에서 전위차계를 이용하여 양성자 첨가반응의 평형상수를 구한 결과 log $K_1$ ; log $K_2$ ; log $K_3$는 9.1; 8.1; 3.6이었다. 또한 위의 리간드와 이미 합성된 리간드 1,12,15-triaza-3,4;9,10-dibenzo-5,8-dioxa-cycloheptadecane(NdienOen$H_4$=$N_3O_2$)를 각각 Ni(II), Cu(II)의 금속이온과의 착물을 합성하여 수용액에서 산을 가해 착물의 산해리반응 속도 상수를 여러온도에서 분광광도법으로 측정하였다. 또한 활성화에너지($E_a$)와 활성화파라메타 ${\Delta}H^{\neq}$, ${\Delta}S^{\neq}$를 구하였다. 그리고 이들의 자료로부터 이 반응계의 타당한 해리메카니즘을 제안하였다.

• 한국식품과학회지
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• 제31권6호
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• pp.1667-1678
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• 1999

식품원재료 171종과 한약재 190종의 metanol 추출물의 항균활성을 조사하였다. 항균활성은 식품의 부패, 변질에 관여한다고 알려진 그람양성세균인 Micrococcus luteus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, 그람음성세균인 Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli 및 효모인 Saccharomyces cerevisiae, Candida albicans, 곰팡이 Penicillium citrinum, Aspergillus flavus, Aspergillus niger를 대상으로 측정하였다. 산수유, 오수유, 감초, 단삼, 오미자, 황련, 명일엽, aroma hop와 bitter hop는 그람양성세균에 항균활성을 나타내었다. Aroma hop와 bitter hop는 그람음성세균에 항균활성을 나타내었다. 한편, 그람양성세균에 대해 강한 항균활성을 나타낸 단삼으로부터 항균물질을 분리, 정제하고 그 구조를 결정하였다. 단삼의 methanol 추출액을 농축하여 ethylacetate로 extraction, silicagel column chromatography, preparative TLC, preparative HPLC 등을 통하여 보존활성물질(T-1)을 분리, 정제하고 UV, $^1H-NMR,\;^{13}C-NMR$, DEPT 및 EI-MS 등의 기기분석한 결과, 단삼의 항균활성물질은 cryptotanshinone으로 결정되었다. 그람양성균에 대하여 MIC는 $3.91{\sim}62.50\;{\mu}g/mL$ 범위에서 강한 보존활성을 나타내었고 특히 Bacillus subtilis에 대하여 MIC는 $3.91\;{\mu}g/mL$로 가장 강한 보존활성을 나타내었다. 따라서 단삼의 cryptotanshinone은 그람양성세균 및 그람음성세균에 의해 변패될 수 있는 식품에서 천연보존료로 이용 가능할 것으로 생각된다.

• Journal of Ginseng Research
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• 제46권6호
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• pp.738-749
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• 2022

Background: Ginseng possesses antitumor effects, and ginsenosides are considered to be one of its main active chemical components. Ginsenosides can further be hydrolyzed to generate secondary saponins, and 20(R)-panaxotriol is an important sapogenin of ginsenosides. We aimed to synthesize a new ginsengenin derivative from 20(R)-panaxotriol and investigate its antitumor activity in vivo and in vitro. Methods: Here, 20(R)-panaxotriol was selected as a precursor and was modified into its derivatives. The new products were characterized by ¹H-NMR, ¹³C-NMR and HR-MS and evaluated by molecular docking, MTT, luciferase reporter assay, western blotting, immunofluorescent staining, colony formation assay, EdU labeling and immunofluorescence, apoptosis assay, cells migration assay, transwell assay and in vivo antitumor activity assay. Results: The derivative with the best antitumor activity was identified as 6,12-dihydroxy-4,4,8,10,14-pentamethyl-17-(2,6,6-trimethyltetrahydro-2H-pyran-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl(tert-butoxycarbonyl)glycinate (A11). The focus of this research was on the antitumor activity of the derivatives. The efficacy of the derivative A11 (IC₅₀ < 0.3 µM) was more than 100 times higher than that of 20(R)- panaxotriol (IC₅₀ > 30 µM). In addition, A11 inhibited the protein expression and nuclear accumulation of the hypoxia-inducible factor HIF-1α in HeLa cells under hypoxic conditions in a dose-dependent manner. Moreover, A11 dose-dependently inhibited the proliferation, migration, and invasion of HeLa cells, while promoting their apoptosis. Notably, the inhibition by A11 was more significant than that by 20(R)-panaxotriol (p < 0.01) in vivo. Conclusion: To our knowledge, this is the first study to report the production of derivative A11 from 20(R)-panaxotriol and its superior antitumor activity compared to its precursor. Moreover, derivative A11 can be used to further study and develop novel antitumor drugs.

• Natural Product Sciences
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• 제12권3호
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• pp.138-143
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• 2006

Our continuing interest on Garcinia and Mesua species has led us to carry out a detail study on the chemistry of the root bark of Garcinia mangostana (Guttiferae) since this part of the plant has not been investigated before, and the strm bark of Mesua corneri (Guttiferae) an uninvestigated species. This study has yielded six xanthones, ${\alpha}-mangostin$ (1), ${\beta}-mangostin$ (2), ${\gamma}-mangostin$ (3), garcinone-D (4), mangostanol (5) and gartanin (6) from Garcinia mangostana and two xanthones rubraxanthone (7) and inophyllin B (8) from Mesua corneri. Structural elucidations were achieved using $^1H,\;^{13}C$ NMR and MS data. The crude hexane and chloroform extracts of the root bark of Garcinia mangostana and the hexane extract of the stem bark of Mesua corneri were found to be active against CEM-SS cell lines with $IC_{50}$ values less than $30\;{mu}g/ml$. Moreover, ${\gamma}-mangostin$ gave a very low $LC_{50}$ value of $4.7\;{mu}g/ml$ while rubraxanthone gave an $LC_{50}$ value of $5.0\;{mu}g/ml$ indicating these two compounds to be potential lead compounds for anti-cancer activity against the CEM-SS cell line. This paper reports the isolation and identification of these compounds as well as bioassay data for the crude extracts, ${\gamma}-mangostin$ and rubraxanthone.

• 생약학회지
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• 제45권1호
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• pp.88-92
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• 2014

Lysimachia foenum-graecum (LF) has been used for home remedy of common cold and headache in China. Foenumoside B from LF has been reported for anti-obesity effects. We used foenumoside B as a marker for content evaluation of different parts of LF. Ethanol extract of LF was used for isolation of foenumoside B and purified further by column chromatography. The structure was identified as foenumoside B by interpretation of spectroscopic analysis, including $^1H$-, $^{13}C$-NMR and FT-ICR-MS. High-performance liquid chromatography (HPLC) method was used to compare the quantitative level of foenumoside B in different parts of LF. Foenumoside B contents in the leaf, stem, and aerial part showed significant differences. Contents of foenumoside B was detected highly in the leaf extracts. The results would be useful for efficient extraction of foenumoside B in LF.