• 한국식품영양학회지
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• 제34권5호
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• pp.553-559
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• 2021

The aim of study to investigate the phytochemicals and biological activities the bark of Betula schmidtii. The studies consisted of the solvent extraction, followed by the isolation of phenolic components 1~3 from ethyl acetate-soluble fraction of Betula schmidtii Bark. Their chemical structures were identified as arbutin (1), ρ-coumaric acid (2) and ferulic acid (3) using Ultraviolet-Visible (UV-Vis) Spectrophotometer, Electrospray Ionization Mass Spectrometry (ESI-MS) (negative ion mode), ¹H-Nuclear Magnetic Resonance (NMR), ¹³C-NMR, ¹H-¹H Correlation Spectroscopy (COSY) and ¹H-¹³C Hetero Nuclear Multiple Quantum Correlation (HMQC) spectral data. Compounds 1~3 shows the anti-oxidant effect with IC₅₀ values of 29.74±1.52, 21.32±1.07 and 34.41±1.24 in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, respectively. Also, compounds 1~3 exhibited mushroom tyrosinase inhibitory activity with IC₅₀ values of 31.14±1.07, 42.54±1.46 and 69.22±1.43 µM, respectively.

• 대한화학회지
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• 제48권4호
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• pp.394-398
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• 2004

우리나라 연안에 널리 분포하고 있는 지충이로부터 3개의 norisoprenoid 화합물들인 (+)-epiloliolide (1), (-)-loliolide (2), apo-9''-fucoxanthinone (3)을 칼럼크로마토그래피와 역상 HPLC를 사용하여 분리$\cdot$정제하였다. 이들 분리한 화합물 1, 2 및 3은 갈조류인 지충이로부터 처음 분리되어 보고하는 것이다. 특히 화합물 1은 비록 육상식물에서 분리된 바 있으나, 해양생물로부터는 처음 분리되어 보고하는 것이다. 분리된 화합물의 구조는 $1^H$ COSY, NOESY, HMQC 그리고 HMBC와 같은 이차원적인 NMR 분광학적인 실험을 이용하여 문헌치와 비교하여 확인하였다.

• Natural Product Sciences
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• 제24권3호
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• pp.189-193
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• 2018

Chemical investigation of the ethyl acetate extract of Gibberella moniliformis JS1055 endophytic fungus derived from a halophyte, Vitex rotundifolia, led to the isolation of nine compounds including 7-butyl-6,8-dihydroxy-3(R)-pent-11-enylisochroman-1-one (1), 7-butyl-6,8-dihydroxy-3(R)-pentylisochroman-1-one (2), 7-butyl6,8-dihydroxy-3(R)-pentylisochroman-1-one (3), $5{\alpha},8{\alpha}$-epidioxyergosta-6,9(11),22-trien-3-ol (4), ergosterol peroxide (5), tetradecanoic acid (6), 8-O-methylfusarubin (7), nicotinic acid (8) and adenosine (9). They were identified by extensive spectroscopic data analysis including 1D, 2D ($^1H-^1H$ COSY, HSQC, HMBC) NMR, and ESIMS. All the isolates (1-9) are reported for the first time from this endophytic fungus.

• Applied Biological Chemistry
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• 제37권4호
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• pp.234-236
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• 1994

국내 토양에서 분리한 방선균에서 살충성물질을 선발하는 연구과정 중 no. 2077 균주가 생산하는 살충성물질을 분리하였다. 살충성물질 SR2077은 UV, $^1H-NMR$, $^BC-NMR$, C-H COSY 등의 방법으로 구조분석한 결과 albocycline으로 동정되었다.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.174-177
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• 2015

A potent α-glucosidase inhibitor (compound I) was isolated from coffee brews by activity-based fractionation and identified as a β-carboline alkaloid norharman (9H-pyrido[3.4-b]indole) on the basis of mass spectroscopy and nuclear magnetic resonance spectra (¹H NMR, ¹³C NMR, and COSY). The norharman showed potent inhibition against α-glucosidase enzyme in a concentration-dependent manner, with an IC₅₀ value of 0.27 mM for maltase and 0.41 mM for sucrase. A Lineweaver-Burk plot revealed that norharman inhibited α-glucosidase enzyme uncompetitively, with a K_i value of 0.13 mM.

• Natural Product Sciences
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• 제19권3호
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• pp.269-274
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• 2013

Nine terpenoids, spinasterone (1), simiarenol (2), phytol (3), lupeol (4), ${\alpha}$-amyrin (5), $1{\beta},4{\beta}$-dihydroxyeudesman-11-ene (6), 3,7-dihydroxyhumula-4,8(15),10(E)-triene (7), 2,6-dihydroxyhumula-3(12),7(13), 9E-triene (8), 23-hydroxybetulin (9) were isolated from the aerial parts of Aster yomena M. Their structures were identified based on 1D and 2D NMR, including $^1H-^1H$ COSY, HSQC, HMBC and NOESY spectroscopic analyses. Compounds 1 - 9 were isolated from this plant for the first time.

• Ocean and Polar Research
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• 제38권4호
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• pp.287-294
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• 2016

Marine sponges have been a remarkably rich source of pharmacologically active and structurally diverse natural products. As a part of our continuing search for novel secondary metabolites of biomedical importance from marine invertebrate, we encountered the sponge Lipastrotethya sp. from Chuuk, Micronesia. The crude organic extract of this animal exhibited considerable cytotoxicity against the K562 cell line. Guided by the $^1H$ NMR analysis, flash chromatography of the crude extract followed by HPLC yielded a new triterpene glycoside, along with ten known saponins of the sarasinoside class. The structure of this new compound was determined by combined spectroscopic methods such as COSY, HSQC and HMBC experiment. Among these metabolites, six compounds exhibited moderate cytotoxicity against ACHN, MDA-MB-231, NCI-H23 and NUGC-3 cell lines.

• KSBB Journal
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• 제15권6호
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• pp.560-565
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• 2000

13-Deacetyl-taxchinin I, a taxoid having a rearranged 11(15\longrightarrow1)-abeo-taxane skeleton, has been isolated and identified from plant cell cultures of Taxus chinensis. The compound has not previously been encountered in nature. Its structure was elucidated by 1-and 2D NMR techniques including H-H COSY, HMQC, and HMBC experiments. This taxoid also provides information for better understanding of structure-activity relationships and biosynthesis, as well as improving the quality control of paclitaxel production.

• 동의생리병리학회지
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• 제19권2호
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• pp.441-445
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• 2005

Tripterygium regelii has been used as an oriental medicine, especially antiparasitic, anti-inflammatory and detoxifying agents in East asia. During our research to develop new antitumor agents from natural products, MeOH ext. and CH2Cl2 ext. of Tripterygium regelii showed the potent antitumor activity. In order to purify active compounds from Tripterygium regelii, activity-guided fractionation was carried out. Silica gel and RP-18 column chromatography for the active fraction led to the isolation of two compounds and their antitumor activities were studied. Those two compounds didn't show potent antitumor activity against human tumor cell lines. The structure of two compounds were determined by $^1H-NMR$, $^{13}C-NMR$, DEPT, $^1H-^{13}C$ COSY and IR spectrum. Compound I and Compound II were turned out to be Celastrol, and ${\beta}-sitosteryl-3-o-{\beta}-D-glucopyranoside$ respectively.

• Journal of Microbiology and Biotechnology
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• 제21권6호
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• pp.582-589
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• 2011

Bioconversion of timosaponin A-III (TA-III), one of the major steroidal saponins isolated from the rhizomes of Anemarrhenae asphodeloides Bunge (Liliaceae), was investigated in Saccharomyces cerevisiae. Five bioconversion products, denoted compounds 2-6, were obtained. Biotransformation metabolite 2 was a stereoisomer of TAIII with a specific isotype F-ring and ${\beta}$-ranged $CH_3$-21, which rarely occurs in nature. The structure of 2 was elucidated by extensive spectroscopic analysis (H-H COSY, HSQC, HMBC), as well as by high-resolution mass spectral analysis. The growth inhibitory activity of compounds 1-6 was assayed against four human cancer cell lines, HepG2, H-1299, HT-29, and HCT-116. Compounds 1 and 2 obviously inhibited the growth of the four types of cancer cells with $IC_{50}$ values being less than 19${\mu}M$. A structure-activity relationship is discussed, and the spirostane-ring F in compounds 1 and 2 appears to be the critical bioactive moiety for the cell growth inhibitory property.