Dae-Young Lee

Publications of Dae-Young Lee

• Rhus parviflora and its biflavonoid constituent, rhusflavone, induce sleep through the positive allosteric modulation of GABA(A)-benzodiazepine receptors.

  Authors: Sabina Shrestha, Ji-Hae Park, Dae-Young Lee, Jin-Gyeong Cho, Suengmok Cho, Hye-Jin Yang, Hye-Im Yong, Min-Seok Yoon, Dae-Seok Han, Nam-In Baek

  Journal of ethnopharmacology. 05/2012;

  ETHNOPHARMACOLOGICAL RELEVANCE: Rhus parviflora is referred as 'Tintidikah' in traditional medicinal system of south Asia (Ayurveda). It is used in treatment of Vāta vikāra, a condition related toETHNOPHARMACOLOGICAL RELEVANCE: Rhus parviflora is referred as 'Tintidikah' in traditional medicinal system of south Asia (Ayurveda). It is used in treatment of Vāta vikāra, a condition related to neurological complications as well as cure for stomach disorders. MATERIALS AND METHODS: Dried and powdered fruits of R. parviflora were extracted with 80% aqueous methanol (RPME). The concentrated extract was successively partitioned with distilled water, ethyl acetate, and n-butanol. All extracts, as well as isolated biflavonoids from R. parviflora, were evaluated for their affinity to the benzodiazepine binding site of GABA(A) receptor. The sedative-hypnotic effects of the fractions were evaluated by measuring sleep latency and sleep duration during pentobarbital-induced sleep in mice after oral administration of the extract fractions. RESULTS: Oral administration of RPME (125mg/kg, 250mg/kg, 500mg/kg, and 1000mg/kg) produced a dose-dependent decrease in sleep latency and an increase in sleep duration in mice treated with pentobarbital. The methanol extract produced a hypnotic effect that was fully blocked by (3)H-Ro 15-1788 flumazenil (FLU). Further, among the solvent fractions, the ethyl acetate fraction exhibited significant activity. Among the isolated compounds, biflavonoids mesuaferrone B (1), rhusflavone (3), and agathisflavone (4) competitively inhibited FLU binding with a K(i) of 0.280μM, 0.045μM, and 0.091μM, respectively. In addition, analysis of the sedative-hypnotic effects of rhusflavone, as well as those of the ethyl acetate, n-butanol, and distilled water fractions revealed that the modulation of both the ethyl acetate fraction and biflavonoid rhusflavone (3) are the most potent in inducing sleep. CONCLUSION: The presence of conjugated ketone and C6-C8″ biflavonoid linkage in rhusflavone may be responsible for BZD-site of the GABA(A) leading to decrease in sleep latency and increase sleep duration.

• Inhibitory effects of actinidiamide from Actinidia polygama on allergy and inflammation.

  Authors: Myun-Ho Bang, In-Gyeong Chae, Eun-Ju Lee, Nam-In Baek, Yoon-Su Baek, Dae-Young Lee, In-Seon Lee, Sam-Pin Lee, Seun-Ah Yang

  Bioscience, biotechnology, and biochemistry. 02/2012; 76(2):289-93.

  Actinidia polygama Max. was subjected to supercritical fluid extraction (SFE), and the resulting ethanol extract of marc (SFEM) was subjected to sequential fractionation with various solvents. EachActinidia polygama Max. was subjected to supercritical fluid extraction (SFE), and the resulting ethanol extract of marc (SFEM) was subjected to sequential fractionation with various solvents. Each extract and fraction was assayed for anti-inflammatory effect. The ethyl acetate fraction (EtOAc) contained the highest level (70.8% inhibition) of anti-inflammatory activity. In order to identify the active constituents, the EtOAc fraction was further fractionated by silica gel and ODS column chromatography. By activity-guided fractionation, an active ceramide was identified as the anti-inflammatory component, and its structure was determined by NMR and MS analysis. The novel ceramide was named actinidiamide, and was found significantly to inhibit nitric oxide (NO) production (30.6% inhibition at 1 µg/mL) in lipopolysaccaride (LPS)-stimulated RAW 264.7 cells and β-hexosaminidase release (91.8% inhibition at 1 µg/mL) in IgE-sensitized RBL-2H3 cells. Thus the presence of actinidiamide conveys allergy and inflammation treatment ability to A. polygama.

• Structural and quantitative analysis of antioxidant and low-density lipoprotein-antioxidant flavonoids from the grains of sugary rice.

  Authors: Dae-Young Lee, Sabina Shrestha, Woo Duck Seo, Min-Ho Lee, Tae-Sook Jeong, Jun Hyun Cho, You Chun Song, Hang Won Kang, Yeong-Deok Rho, Nam-In Baek

  Journal of medicinal food. 02/2012; 15(4):399-405.

  Abstract Grains of sugary rice were extracted with 80% aqueous methanol, and the concentrated extracts were successively partitioned using ethyl acetate, n-butanol, and water. From the n-butanolAbstract Grains of sugary rice were extracted with 80% aqueous methanol, and the concentrated extracts were successively partitioned using ethyl acetate, n-butanol, and water. From the n-butanol fractions, four flavonoid glycosides were isolated through repeated silica gel, octadecyl silica gel, and Sephadex LH-20 column chromatographies. Based on the nuclear magnetic resonance, mass spectrometry, and infrared spectroscopic data, the chemical structures of the compounds were determined to be taxifolin-7-O-β-d-glucopyranoside (1), hyperin (2), isoquercitrin (3), and quercetin gentiobioside (4). These compounds were isolated from the grains of sugary rice for the first time. All isolated compounds were tested for antioxidant activity and low-density lipoprotein (LDL)-antioxidative activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and LDL assays. Compound 1 exhibited a strong scavenging effect on DPPH, with a 50% inhibition concentration (IC(50)) value of 8.1 μM, and also inhibited LDL oxidation with an IC(50) value of 40.0±20 μM. A simple and efficient high-performance liquid chromatography/diode array detection method for the simultaneous determination of the four bioactive flavonoids (1-4) has been developed and applied to their content determination in the sugary rice. The grains were extracted by 80% methanol, and the contents of 1, 2, 3, and 4 were determined to be 1.12±0.045, 0.65±0.011, 0.68±0.032, and 0.89±0.021 mg/g, respectively.

• Flavonoids from silkworm droppings and their promotional activities on heme oxygenase-1.

  Authors: Ji-Hae Park, Dae-Young Lee, Pyeong Yun, Seung-Woo Yeon, Jong Hee Ko, Yong-Soon Kim, Nam-In Baek

  Journal of Asian natural products research. 04/2011; 13(4):377-82.

  A new flavane glucoside, 7,2'-dihydroxy-8-hydroxyethyl-4'-methoxyflavane-2'-O-β-d-glucopyranoside (3), along with three known flavonoids, 7,2'-dihydroxy-8-prenyl-4'-methoxyflavane (1), euchrenoneA new flavane glucoside, 7,2'-dihydroxy-8-hydroxyethyl-4'-methoxyflavane-2'-O-β-d-glucopyranoside (3), along with three known flavonoids, 7,2'-dihydroxy-8-prenyl-4'-methoxyflavane (1), euchrenone a(7) (2), and 7,2'-dihydroxy-8-prenyl-4'-methoxy-2'-O-β-d-glucopyranosylflavane (4), was isolated from silkworm droppings. The structures of the compounds were elucidated on the basis of 1D and 2D NMR spectroscopic analyses and optical rotational characteristics. The compounds isolated from silkworm droppings were evaluated for their effects on heme oxygenase-1 (HO-1) activity. Compounds 1 and 3 increased the expression of HO-1 in HepG2 cells. HO-1 is an antioxidant enzyme that catabolizes heme to carbon monoxide, free iron, and biliverdin, all of which are involved in the suppression of inflammatory mediators.

• A glycosidic spinasterol from Koreana stewartia promotes procollagen production and inhibits matrix metalloproteinase-1 expression in UVB-irradiated human dermal fibroblasts.

  Authors: Tae Hoon Lee, Sang Min Lee, Dae-Young Lee, Youngsook Son, Dae Kyun Chung, Nam-In Baek, Jiyoung Kim

  Biological & pharmaceutical bulletin. 01/2011; 34(5):768-73.

  Methanol extract of Koreana stewartia leaves (SKE) stimulated collagen production in ultraviolet-B (UVB)-irradiated human fibroblast cells. An active compound was isolated from SKE by successiveMethanol extract of Koreana stewartia leaves (SKE) stimulated collagen production in ultraviolet-B (UVB)-irradiated human fibroblast cells. An active compound was isolated from SKE by successive partitioning and chromatography, and the chemical structure was determined to be 3-O-β-D-glucopyranosylspinasterol (spinasterol-Glc) by spectroscopic characterization. Spinasterol-Glc increased collagen production in the supernatant of UVB-irradiated dermal fibroblast cell cultures in a dose-dependent manner. The effects of spinasteol-Glc on expression of procollagen and matrix metalloproteinase-1 (MMP-1) were further evaluated. We found that the compound stimulated collagen production in UVB-treated fibroblasts than in vehicle-treated control cells by about 3-fold. In addition, we also demonstrate that the compound increased the mRNA and protein levels of procollagen in UVB-treated fibroblast cells, while it inhibited expression of MMP-1. These results indicate that spinasterol-Glc protects fibroblast cells from the adverse effects of UV radiation via stimulation of procollagen synthesis as well as inhibition of MMP-1 expression. Spinasterol-Glc may be useful in the future development of therapeutic and cosmetic applications.

• Flavonoids from the buds of Rosa damascena inhibit the activity of 3-hydroxy-3-methylglutaryl-coenzyme a reductase and angiotensin I-converting enzyme.

  Authors: Eun-Kyung Kwon, Dae-Young Lee, Hyungjae Lee, Dae-Ok Kim, Nam-In Baek, Young-Eon Kim, Hae-Yeong Kim

  Journal of agricultural and food chemistry. 01/2010; 58(2):882-6.

  Rosa damascena has been manufactured as various food products, including tea, in Korea. A new flavonoid glycoside, kaempferol-3-O-beta-D-glucopyranosyl(1-->4)-beta-D-xylopyranoside, named roxylosideRosa damascena has been manufactured as various food products, including tea, in Korea. A new flavonoid glycoside, kaempferol-3-O-beta-D-glucopyranosyl(1-->4)-beta-D-xylopyranoside, named roxyloside A was isolated from the buds of this plant, along with four known compounds, isoquercitrin, afzelin, cyanidin-3-O-beta-glucoside, and quercetin gentiobioside. The chemical structures of these compounds were determined by spectroscopic analyses, including FAB-MS, UV, IR, (1)H and (13)C NMR, DEPT, and 2D NMR (COSY, HSQC, and HMBC). All the isolated compounds except cyanidin-3-O-beta-glucoside exhibited high levels of inhibitory activity against 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase with IC(50) values ranging from 47.1 to 80.6 microM. Cyanidin-3-O-beta-glucoside significantly suppressed angiotensin I-converting enzyme (ACE) activity, with an IC(50) value of 138.8 microM, while the other four compounds were ineffective. These results indicate that R. damascena and its flavonoids may be effective to improve the cardiovascular system.

• Sterols Isolated from Nuruk (Rhizopus oryzae KSD-815) Inhibit the Migration of Cancer Cells.

  Authors: Dae-Young Lee, Sang-Jin Lee, Ho-Young Kwak, Lakoon Jung, Jieun Heo, Sungyoul Hong, Gye-Won Kim, Nam-In Baek

  Journal of microbiology and biotechnology. 11/2009; 19(11):1328-32.

  An activity-guided fractionation method was used to isolate anticancer components from Nuruk (Rhizopus oryzae KSD-815:KSD-815). Dried powder of KSD-815 was extracted with 80% methanol and partitionedAn activity-guided fractionation method was used to isolate anticancer components from Nuruk (Rhizopus oryzae KSD-815:KSD-815). Dried powder of KSD-815 was extracted with 80% methanol and partitioned successively using nhexane, ethyl acetate, n-butanol, and water. The n-hexane and n-butanol fractions showed a strong antimigratory effect on human cancer cells. Both of these fractions were subjected to separation and purification procedures using silica gel, octadecyl silica gel, and Sephadex LH-20 column chromatographies to afford four purified compounds. These were identified as ergosterol peroxide (1), stigmast- 5-en-3beta,7beta-diol (2), ergosta-7,22-dien-3beta,5alpha,6beta,9alpha-tetraol (3), and daucosterol (4), respectively, by spectroscopic methods such as nuclear magnetic resonance spectrometry, mass spectrometry, and infrared spectroscopy, and comparison with those in the literature. Compounds 1-4 were isolated from KSD-815 for the first time. Compounds 1 and 4 inhibited the migration of MDA-MB-231 cells at concentrations lower than 20 micronM.

• Lignans from the fruits of the red pepper (Capsicum annuum L.) and their antioxidant effects.

  Authors: Dae-Young Lee, Do-Gyeong Lee, Jin-Gyeong Cho, Myun-Ho Bang, Ha-Na Lyu, Youn-Hyung Lee, Se-Young Kim, Nam-In Baek

  Archives of pharmacal research. 10/2009; 32(10):1345-9.

  The fruits of Capsicum annuum were extracted using 80% aqueous MeOH, and fractionated using EtOAc and water. Repeated column chromatography using silica gel, octadecyl silica gel, and Sephadex LH-20The fruits of Capsicum annuum were extracted using 80% aqueous MeOH, and fractionated using EtOAc and water. Repeated column chromatography using silica gel, octadecyl silica gel, and Sephadex LH-20 for the EtOAc fraction led to the isolation of a new lignan glycoside and a known one, icariside E(5). From the results of spectroscopic data, including EIMS, FABMS, UV, IR, (1)H and (13)C-NMR, DEPT, and 2D-NMR (COSY, HSQC, HMBC), the chemical structure of the new lignan glycoside was determined as (8R)-isodehydrodiconiferyl alcohol-4'-O-(6''-vanilloyl)-beta-D-glucopyranoside named vanilloylicariside E(5). All isolated compounds were tested for antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Icariside E(5) (2) and (8R)-Isodehydrodiconiferyl alcohol (3) exhibited a strong scavenging effect on DPPH (2: IC(50)=42.1 microM, 3: IC(50)=4.5 microM).

• Design and Performance Test of Comb-Shaped Clamp/Spacer for Improvement of Recirculation Filter Efficacy in a Hard Disk Drive

  Authors: Sung-Eun Park, Dae-Young Lee, Jae-Hong Park, Tae-Sik Kang, Jin-Gyoo Yoo, Jungho Hwang

  Magnetics, IEEE Transactions on. 02/2009;

  With the recent increase of the rotational speed of hard disk drives, nanoparticle contamination can cause serious problems including thermal asperity. We designed a comb-shaped clamp and spacer toWith the recent increase of the rotational speed of hard disk drives, nanoparticle contamination can cause serious problems including thermal asperity. We designed a comb-shaped clamp and spacer to improve the efficacy of the recirculation filter in the operation of the hard disk drive (HDD). We calculated flow characteristics by a commercial computational fluid dynamics (CFD) code for six cases of the comb-shaped clamp and spacer. The calculation results showed that the outward velocity was the highest when the comb-shape angle was 45deg. We measured temporal variations of particle concentration during the operation of the HDD by experiments. Considering the decay rate and the percent clean-up of particle concentration, we found the case of 45deg to be the best design.

• A new lignan glycoside from the fruits of Cornus kousa Burg.

  Authors: Dae-Young Lee, Ki Hyun Yoo, In Sik Chung, Ji Young Kim, Dae Kyun Chung, Dae Keun Kim, Sung-Hoon Kim, Nam-In Baek

  Archives of pharmacal research. 08/2008; 31(7):830-3.

  A new lignan glycoside, (7'S, 8'R)-dihydrodehydrodiconiferyl alcohol-4'-O-beta-D-xylopyranoside (1), named cornuskoside A, was isolated from the fruits of Cornus kousa. The structure of the compoundA new lignan glycoside, (7'S, 8'R)-dihydrodehydrodiconiferyl alcohol-4'-O-beta-D-xylopyranoside (1), named cornuskoside A, was isolated from the fruits of Cornus kousa. The structure of the compound was determined by spectroscopy, including FABMS, UV, IR, (1)H-and 13C-NMR, DEPT and 2D-NMR (COSY, HSQC, and HMBC). This new lignan glycoside, along with its aglycone, (7'S, 8'R)-dihydrodehydrodiconiferyl alcohol (3), and another lignan with a similar skeleton, (-)-balanophonin (2), which have been previously isolated from this plant, were evaluated for cytotoxicity in human cancer cell lines such as HeLa, MCF-7, SK-MEL-5, and SK-OV-3. Compounds 2 and 3 showed cytotoxicity against HeLa [IC50 = 29.1 microM (2), 45.5 microM (3)], MCF-7 [IC50 = 29.2 microM (2), 28.2 microM (3)], SK-MEL-5 [IC50 = 31.3 microM (2), 32.3 microM (3)], and SK-OV-3 [IC50 = 33.4 microM (2), 43.4 microM (3)] cell lines.

• Lignans from the fruits of Cornus kousa Burg. and their cytotoxic effects on human cancer cell lines.

  Authors: Dae-Young Lee, Myoung-Chong Song, Ki Hyun Yoo, Myun-Ho Bang, In Sik Chung, Sung-Hoon Kim, Dae Keun Kim, Byoung-Mog Kwon, Tae-Sook Jeong, Mi-Hyun Park, Nam-In Baek

  Archives of pharmacal research. 05/2007; 30(4):402-7.

  The fruits of Cornus kousa Burg. were extracted with 80% aqueous MeOH, and the concentrated extract partitioned with EtOAc, n-BuOH and H2O. Six lignans were isolated from the EtOAc fraction throughThe fruits of Cornus kousa Burg. were extracted with 80% aqueous MeOH, and the concentrated extract partitioned with EtOAc, n-BuOH and H2O. Six lignans were isolated from the EtOAc fraction through repeated silica gel, ODS and Sephadex LH-20 column chromatographies. From the physico-chemical data, including NMR, MS and IR, the chemical structures of the compounds were determined to be (+)-pinoresinol (1), (-)-balanophonin (2), (+)-laricresinol (3), erythro-guaiacylglycerol-beta-coniferyl aldehyde ether (4), threo-guaiacylglycerol-beta-coniferyl aldehyde ether (5) and dihydrodehydrodiconiferyl alcohol (6), which were isolated for the first time from this plant. Most of these compounds showed cytotoxicity against human colon carcinoma (HCT-116) and human hepatocellular carcinoma (HepG2) cell lines in vitro, with IC50 values ranging from 19.1 to 71.3 microg/mL.

• Electrohydrodynamic printing of silver nanoparticles by using a focused nanocolloid jet

  Authors: Dae-Young Lee, Yun-Soo Shin, Sung-Eun Park, Tae-U Yu, Jungho Hwang

  Applied Physics Letters. 03/2007;

  As a direct write technology, the electrohydrodynamic printing of silver nanoparticles by using a focused nanocolloid jet is introduced. In this letter, two categorized types of examples ofAs a direct write technology, the electrohydrodynamic printing of silver nanoparticles by using a focused nanocolloid jet is introduced. In this letter, two categorized types of examples of two-dimensional patterning were printed by using the electrohydrodynamic printing method. A spiral-type inductor was printed to demonstrate the feasibility of the electrohydrodynamic printing as a fabrication process. The printed spiral inductor produced 9.45 μ H and exhibited approximately five times larger resistivity (9.5 μΩ cm ) than that of bulk silver after the sintering process. Then, complex geometries having square- and round-shape patterns were also printed.

• A New Method for Analysis of Differential Optical Absorption Spectra using Wavelet Transform and Independent Component Analysis

  Authors: Sung-Hwan Han, Hyeon-Ho Kim, Dae-Sung Kim, Geun-Taek Ryu, Hun Choi, Dae-Young Lee, Hyeon-Deok Bae

  Instrumentation and Measurement Technology Conference, 2005. IMTC 2005. Proceedings of the IEEE; 06/2005

  This paper presents a new method for analysis of differential optical absorption spectroscopy (DOAS), which has been used for nondestructive air monitoring and has used the LS (least squares) methodThis paper presents a new method for analysis of differential optical absorption spectroscopy (DOAS), which has been used for nondestructive air monitoring and has used the LS (least squares) method to calculate trace gas concentrations due to its computational simplicity. Since the LS method is insufficient to recover the desired spectra perfectly due to sparsity characteristic, we applies the ICA (independent component analysis) method to the DOAS system. If the sparsity of reference spectra in the DOAS system imposes the assumption of independence, the ICA algorithm can be used to regress the observed spectrum on the estimates of the reference spectra. In this paper, for enhancing this sparsity, we apply the wavelet transform into the DOAS spectra, and estimate the independent components from the decomposition signal that the wavelet transform can yield the input in the ICA. The ICA algorithm can be seen as a preprocessing method where the ICs of the references are used as the input in the regression. When the measured spectrum data is reconstructed by regression with the ICs of the decomposition signal, the concentration is calculated by LS method with the reconstruction spectrum. The performance of the proposed method is evaluated in simulation studies using synthetic data and real measured data.

• A new lignan glycoside from the rhizomes of Imperata cylindrica.

  Authors: Dae-Young Lee, Kyung-Min Han, Myoung-Chong Song, Do-Gyeong Lee, Yeong-Deok Rho, Nam-In Baek

  Journal of Asian natural products research. 10(3-4):337-41.

  A new lignan glycoside, 6-acetyl-1-[1,3-(4,4'-dihydroxy-3,3'-dimethoxy-beta-truxinyl)-beta-d-fructofuranosyl]-alpha-d-glucopyranoside (1), named impecyloside, was isolated from the rhizomes ofA new lignan glycoside, 6-acetyl-1-[1,3-(4,4'-dihydroxy-3,3'-dimethoxy-beta-truxinyl)-beta-d-fructofuranosyl]-alpha-d-glucopyranoside (1), named impecyloside, was isolated from the rhizomes of Imperata cylindrica. The structure of the compound was determined by spectroscopic data including FABMS, UV, IR, 1H NMR and 13C NMR (DEPT) and 2D NMR (COSY, HSQC, HMBC).