• 생약학회지
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• 제31권1호
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• pp.39-44
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• 2000

A sterol mixture, 3-O-glucosides of these sterols, 6'-O-fattyacyl ester of these sterol glucosides, kaempferol, quercetin and isoquercitrin were isolated from the whole plants of Hypericum ascyron L. The sterols were found to be a mixture of ${\beta}-sitosterol$, campesterol and stigmasterol by GC-MS. The kinds of fatty acids linked at 6'-OH of sterol glucoside ester mixture were shown to be palmitic acid, stearic acid, oleic acid and linoleic acid by GC-MS. Three flavonoids were identified by spectroscopic methods and comparisons of mixed mp and co-TLC with authentic specimens.

• Journal of Applied Biological Chemistry
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• 제51권2호
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• pp.57-60
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• 2008

Eight compounds, including 2 flavones, luteolin (1) and apigenin (2), 2 flavonols, kaempferol (3) and quercetin (4), and 4 flavonoid glucosides, luteolin-7-O-${\beta}$-D-glucoside (5), apigetrin (6), astragalin (7), and isoquercitrin (8), isolated from the whole herb of Sonchus oleraceus L. were analyzed on the basis of chemical and spectroscopic evidence. This was the first time to report compounds 3, 4, 6, 7 and 8 from the Sonchus oleraceus L. The antioxidant activities of the isolated flavonoids and their glucoside derivatives were evaluated by DPPH free radical-scavenging assay, showing that compounds 1, 3, 4 and 8 exhibited stronger antioxidant activities compared with ${\alpha}$, tocopherol and curcumin. Flavonoids containing more hydroxyl groups exhibited better antioxidant activities. The antioxidant activity of flavonols was superior to their corresponding flavones, and that of aglycone are more potent than their glucoside derivatives.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.298-304
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• 2018

The single-vessel multienzyme UDP-${\alpha}$-$\text\tiny{D}$-glucose recycling system was coupled with a forward glucosylation reaction to produce novel glucose moiety-conjugated derivatives of different tetracycline antibiotic analogs. Among five tetracycline analogs used for the reaction, four molecules (chlorotetracycline, doxytetracycline, meclotetracycline, and minotetracycline) were accepted by a glycosyltransferase enzyme, YjiC, from Bacillus licheniformis to produce glucoside derivatives. However, the enzyme was unable to conjugate sugar units to rolitetracycline. All glucosides of tetracycline derivatives were characterized by ultraviolet absorbance maxima, ultra-pressure liquid chromatography coupled with photodiode array, and high-resolution quadruple time-of-flight electrospray mass spectrometry analyses. These synthesized glucosides are novel tetracycline derivatives.

• Natural Product Sciences
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• 제9권4호
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• pp.213-219
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• 2003

Five aromatic compounds, of which two are new glucosides, and six flavonols were isolated and identified for the first time from the flower heads and aerial shoots of Helichrysum conglobatum (Asteraceae). Their structures were established on the basis of chemical and spectroscopic methods including UV, MS, 1D- and 2D-NMR. Some fractions and isolates were screened for anti-microbial activities. This is the first report of the isolation of the chemical constituents of this species.

• 생약학회지
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• 제13권1호
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• pp.1-6
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• 1982

Gentiana uchiyamana Nakai is a perennial herb in Gentianaceous plants. From the root of Gentiana uchiyamana Nakai, the bitter secoiridoid glucosides were isolated and identified as gentiopicroside and swertiamarin. A high-performance liquid chromatographic method for quantitative determination of bitter component, i.e. gentiopicroside in the roots of Gentiana scabra and G. uchiyamana Nakai was developed, using a ${\mu}$-Bondapak $C_{18}$ column and methanol-water mobile phases. The content of gentiopicroside was calculated from calibration curve previously prepared using the standard, 3.55% in the roots of Gentiana scabra and 1.58% in Gentiana uchiyamana Nakai.

• Natural Product Sciences
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• 제8권4호
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• pp.141-143
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• 2002

Two flavone glucosides have been isolated from the leaves of Helianthus tuberosus (jerusalem artichoke). Their structures were identified as kaempferol 3-O-glucoside (1) and quercetin 7-O-glucoside (2) by spectroscopic analysis and confirmed by comparison with reported data. These flavonoids were isolated for the first time from this plant part.

• Archives of Pharmacal Research
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• 제29권7호
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• pp.587-590
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• 2006

Three naphthopyrone glucosides, cassiaside (1), $rubrofusarin-6-O-{\beta}-D-gentiobioside$ (2), and $toralactone-9-O-{\beta}-D-gentiobioside$ (3), were isolated from the BuOH-soluble extract of the seeds of Cassia tora as active constituents, using an in vitro bioassay based on the inhibition of advanced glycation end products (AGEs) to monitor chromatographic fractionation. The structures of 1-3 were determined by spectroscopic data interpretation, particularly by extensive 1D and 2D NMR studies. All the isolates (1-3) were evaluated for the inhibitory activity on AGEs formation in vitro.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1680-1682
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• 2003

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.29-36
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• 2004

토양으로부터 CGTase를 생산하는 새로운 호열성 세균을 분리하였으며, 형태 및 생리적 특성과 16S ribosomal DNA의 염기서열을 분석한 결과 Geobacillus thermosacchalytycus 로 동정하였다. 호열성 G. thermosacchalytycus가 분비하는 CGTase를 한외여과, 소수성 Phenyl Sephadex CL-4B 클로마토그래피 , 그리고 gel filtration의 순서로 분리 정제하여 정제도 28.2배, 정제수율 12.2%, 그리고 specific activity가 4952.5 units/mg인 CGTase를 얻을 수 있었다. 정제된 CGTase의 분자량은 69,000 dalton이었고, terminal amino sequence는 Asn-Leu-Asn-Lys-Val-Asn-Phe-Thr-Ser-Asp-Val-Val-Tyr-Gln-Ile이었다. 최적 pH 및 온도는 각각 pH 6와$ 50^{\circ}C$였고, pH 6-8과 $60^{\circ}C$에서 장기간 보존할 수 있는 중성 pH의 내열성 효소임을 알 수 있었다. 내열성 CCTase의 cyclization과 coupling 반응의 특정을 검토한 결과 G. thermosacchalytycus가 생산하는 내열성 효소는 $\alpha$-type CGTase이었고, cyclization 반응보다는 coupling반응에 적합한 당전이성이 높은 효소임을 알 수 있었다. 당전이 반응에서 기질 특이성을 검토한 결과 당공여체로는 가용성 전분 그리고 당수용체로는 배당체인 stevioside에 대해 높은 기질 특이성을 보였다. 당전이 반응은 당수용체와 당공여체가 효소와 무작위로 결합하여 진행되는 random ternary complex mechanism으로 반응이 수행되었다.

• 생명과학회지
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• 제21권3호
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• pp.464-467
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• 2011

퀘세틴은 양파에 있는 주요한 플라보노이드이고, 항산화제 역할을 한다. 양파에 있는 퀘세틴은 주로 배당체 형태로 존재한다. 흑양파는 습도 90%와 온도 $60^{\circ}C$ 조건 하에서 30일 동안의 숙성처리과정으로 만들어진다. 흑양파 제조과정 전후의 양파 속에 있는 퀘세틴과 퀘세틴 배당체들은 HPLC-ESI/MS/MS를 이용하여 분석되었다. 생양파 속에는 퀘세틴 단당체와 퀘세틴 이당체가 동정되었고, 반면에 흑양파 속에는 퀘세틴만이 존재하였다. 그러한 결과들은 생양파에 있는 퀘세틴 배당체(단당체와 이당체)들은 숙성과정 동안 해당과정이 일어난다는 것을 의미한다. 이러한 분석프로파일은 숙성과정 동안 발생되는 양파의 주요한 두 개의 퀘세틴 배당체들의 변화를 추정하는데 용이한 방법을 제공할 것이다.