김철영 교수

The iridoid glycoside, geniposide was purified by centrifugal partition chromatography (CPC) with a two-phase solvent system composed of ethyl acetate:isopropanol:water (3:2:5, v/v) from an 80% methanolic extract of fruits of Gardenia jasminoides. Preparative CPC yielded 56.2 mg of geniposide in a one-step separation of 500 mg of extract, with a purity of 95% as determined by HPLC. Isolated geniposide was identified from its 1H-NMR, 13C-NMR and MS spectra.

New blue iridium complexes with a trimethylsilyl group as a bulky electron donating group, Ir(F2-p-trimethylsilyl)2(fptp) and Ir(F2-m-trimethylsilyl)2(fptp), were synthesized via μ-chloro-bridged dimer and perfluoropropylated triazole-based ancillary ligands and then characterized using various spectroscopic studies. Both Ir(F2-p-trimethylsilyl)2(fptp) and Ir(F2-m-trimethylsilyl)2(fptp) exhibited high photoluminescence quantum efficiencies of 75 ± 5% and 76 ± 5% in films, respectively. The DFT c

Abstract Mangiferin was separated from rhizomes of Anemarrhena asphodeloides extract using centrifugal partition chromatography (CPC) with a two‐phase solvent system composed of ethyl acetate‐isopropanol‐water (3∶2∶5, v/v). Mangiferin (22.5 mg) was successfully isolated from methanolic extracts (957 mg) in only one step, and the purity of isolated compound was determined to be over 95% by HPLC analysis. The structure of mangiferin was identified by 1H, 13C NMR and ESI‐MS spectral data analysis.

Flavanone glycosides were successfully separated from the crude extract of Poncirus trifoliata by preparative centrifugal partition chromatography with a two-phase solvent system composed of ethyl acetate-acetonitrile-water (3:2:5, v/v/v). Naringin (50.0 mg), neoponcirin (16.8 mg), and poncirin (71.9 mg) were purified from the 524 mg crude extract in only one step. The purities of the isolated compounds were determined to be over 90% by HPLC analysis and their structures were elucidated by (1)H

Centrifugal partition chromatography was applied to separate arctigenin and matairesinol from Forsythia koreana extract with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (5:5:5:5 v/v). Using this method, arctigenin and matairesinol were successfully separated from partially purified F. koreana extracts in only one step. The purities of isolated compounds were determined to be over 90% by HPLC analysis.

The fruit of <i>Schisandra chinensis</i>, Omija, is a well-known traditional medicine used as an anti-tussive and anti-diarrhea agent, with various biological activities derived from the dibenzocyclooctadiene-type lignans. A high-pressure liquid chromatography-diode array detector (HPLC-DAD) method was used to determine seven lignans (schisandrol A and B, tigloylgomisin H, angeloylgomisin H, schisandrin A, B, and C) in the different plant parts and beverages of the fruit of <i>S. chinensis</i> g

Unlike other members of the leguminous family that are generally used as food, Rhynchosia volubilis, a small soybean with a black seed coat, is used as a folk medicine in Korea. Using an on-line high performance liquid chromatography-2,2ʹ-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation screening system, one peak in the ethyl acetate fraction exhibited outstanding antioxidant capacity. To purify and determine the antioxidant compounds associated with this peak, we developed a cent

Activity-guided separation of antioxidant response element (ARE)-inducing constituents from the rhizomes of Atractylodis Rhizoma Alba was performed by the combination of centrifugal partition chromatography (CPC) and an ARE luciferase reporter assay. From 3 g of the active <i>n</i>-hexane fraction, one polyacetylene, (6<i>E</i>,12<i>E</i>)-tetradeca-6,12-dien-8,10-diyne-1,3-diyl diacetate (47.3 mg), and two sesquiterpenes, atractylenolide I (40.9 mg), and selina-4(14),7(11)-dien-8-one (6.0 mg) w

High-performance liquid chromatography coupled to an on-line ABTS+-based assay (on-line HPLC-ABTS+) system was used to determine the principle antioxidants in azalea flowers. Three flavonoids, myricetin, quercetin, and kaempferol, recovered in ethyl acetate extracts of azalea flowers were determined to have antioxidant activities. These three flavonoids were isolated and purified by successive centrifugal partition chromatography (CPC) using two different biphasic solvent systems, consisting of

<i>Alpinia oxyphylla</i> Miq. (Zingiberaceae) extract exerts protective activity against <i>tert</i>-butyl hydroperoxide-induced toxicity in HepG2 cells, and the antioxidant response element (ARE) luciferase activity increased 6-fold at 30 μg/mL in HepG2 cells transiently transfected with ARE-luciferase. To identify active molecules, activity-guided isolation of the crude extract led to four sesquiterpenes (<b>1</b>, <b>2</b>, <b>5</b>, <b>6</b>) and two diarylheptanoids (<b>3</b> and <b>4</b>)