• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.179-184
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• 1997

To search for useful antioxidants from plant materials, we investigated the antioxidative activity in the methanol extracts of 30 Chinese medicinal plants using DPPH method. The highest activity $(RC_{50}:\;12\;{\mu}g)$ was showed in the methanol extract of Rosa rugosa, followed by Potentilla fruticosa $(14\;{\mu}g)$, P. fragarioides $(16\;{\mu}g)$. And Geum aleppicum $(18\;{\mu}g)$. From the leaves of R. rugosa, two antioxidative compounds were isolated by a bioassay guided purification and identified as isoquercitrin and ${\beta}-glucogallin$ on the basis of $^1H-,\;^{13}C-\;NMR$, and FAB-MS data. ${\beta}-Glucogallin$ is the first report in this plant. The DPPH radical scavenging activity of ${\beta}-glucogallin\;(RC_{50}:\;8.5\;{\mu}g)$ was more effective than those of ${\alpha}-tocopherol\;(12\;{\mu}g)$ and BHA $(14\;{\mu}g)$.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.40.2-40.2
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• 2010

In this study, oxidized alginate/gelatin/biphase calcium phosphate (BCP)- based hydrogel composites were fabricated. Alginate sodium was oxidized by periodate. The oxidized product was confirmed by using $^1H$ and $^{13}C$ NMR spectra. The number average molecular weight ($M_n$), the average molecular weight ($M_w$) of the oxidized alginate were determined by Gel Permeation Chromatography (GPC). The hydrogel was formed from the oxidized alginate and gelatin solution via Schift-base reaction. The hydrogel showed a highly porosity by a Scanning Electron Microscope (SEM) and Mercury Intrusion Porosimetry (MIP). Crosslinked density of the gel matrix were assessd by trinitrobenzene sulfonic acid (TNBS) assay that shows a high effect on swelling ratio. Increment of the crosslinked desity resulted in enhancing compressive strength of the hydrogel composite. The cytotoxity of hydrogel was assessed with osteoblast MG-63. The hydrogel composites show a high compatibility. The obtained results showed a potential application for bone regeneration in future.

• Analytical Science and Technology
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• v.18 no.2
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• pp.104-111
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• 2005

Several solvents were used to fractionate an extract obtained from the chapped root bark of Ulmus davidiana Planchon. The each fractionary part was condensed under reduced pressure and then examined to investigate the inhibitory effect on MMPs by modified gelatin zymography, where EA fraction showed the inhibition effect on the activity of MMPs. A compound showing inhibition effect on the MMPs was isolated and purified from EA fraction. Under IR, $^1H$- and $^{13}C$- NMR analyses it is very close to a catethin. This substance showed 48% inhibition effect on measurement of MMP-9 activity at 5 mM and 43% at 10 mM. To verify the effect of this substance on cells, human hepatoma, SK-Hep-1 cells as a cancer model, and Chang liver cells as a normal model were selected. MTT assay was performed to examine the cell viability by treatment of $1{\mu}L/mL$ of the purified substance on cells. The purified substance showed negligible toxicity on human liver cell line.

• Natural Product Sciences
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• v.27 no.4
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• pp.245-250
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• 2021

The methylglyoxal (MGO) trapping constituents from Malus baccata L. were investigated using incubation of MGO and crude extract under physiological conditions followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Sieboldin was identified as a major active molecule representing MGO-trapping activity of the crude extract. After reaction of sieboldin and MGO, remaining MGO was calculated by microplate assay method using imine (Schiff base) formation of 2,4-dinitrophenylhydrazine (DNPH) and aldehyde group. After 4 h incubation, sieboldin trapped over 43.8% MGO at a concentration of 0.33 mM and showed MGO scavenging activity with an RC₅₀ value of 0.88 mM for the incubation of 30 min under physiological conditions. It was also confirmed that sieboldin inhibited the production of advanced glycation end products (AGE) produced by bovine serum albumins (BSA)/MGO. Additionally, MGO trapping mechanism of sieboldin was more specifically identified by ¹H-, ¹³C-, 2D NMR and, confirm to be attached to the position of C-3' (or 5').

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.192-198
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• 1994

Zeaenol isolated from the culture filtrate of a fungal weed pathogen Drechslera portulacae, which causes necrosis on the leaves and stem of purslane (Portulaca oleracea). Its structure was determined by single-crystal x-ray diffraction method together with assignments of $^1H$ and $^{13}C$-NMR experiments. Zeaenol inhibited root length of Echinochloa crus-galli and Abutilon avicennae by 22.8% and 54.8% at $3{\times}10^{-6}M$, respectively.

• Journal of Pharmaceutical Investigation
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• v.27 no.3
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• pp.165-171
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• 1997

Ibuprofen, a nonsteroidal antiinflammatory, analgesic and antipyretic drug, has several limitations in clinical application because of low solubility in water and gastrointestinal irritation. Effect of ibuprofen/$2-Hydroxypropyl-{\beta}-cyclodextrin\;(HP{\beta}CD)$ inclusion compound on release of suppository was investigated. Complex formation was confirmed by $^{1}H-\;and\;^{13}C-NMR$ spectroscopy. The release of ibuprofen from suppository base in vitro was significantly increased by the complexation with $HP{\beta}CD$. The release of ibuprofen from hydrophilic base was faster than that from hydrophobic base. In vivo studies, the release rate of ibuprofen from suppository was accelerated after rectal administration in complex form. This results suggested that ibuprofen/$HP{\beta}CD$ complex can be practically used for suppository to have faster effect of ibuprofen with reduced side effect.

• Carbon letters
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• v.10 no.4
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• pp.325-328
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• 2009

This cycloaddition of [70]fullerene with methyl azidoacetate in benzene under ultrasonic irradiated condition afforded the closed [5,6]-bridged aziridino[70]fullerene derivative, which was unusual product of cycloaddition to the 5,6-junction of fullerene. Its structure was determined by FAB-MS, UV-vis, $^1H-$ and $^{13}C$-NMR spectral data. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films were self-assembled using the layer-by-layer method on the reactive of glass slides functionalized with 3-mercaptopropyl trimethoxysilane. The functionalized glass slides were alternately soaked in the solution containing closed the [5,6]-bridged aziridino[70]fullerene and 4-aminothiophenoxide/hexanethiolate-protected gold nanoparticles. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films have grown up to 5 layers depending on the immersion time. The self-assembled nanoparticle multilayer films were characterized using UV-vis spectroscopy showed that the surface plasmon band of gold at 527 nm gradually became more evident as successive layers were added to the films.

• Polymer(Korea)
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• v.32 no.4
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• pp.295-304
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• 2008

This study examined the oxidative polycondensation reaction of 2-[(pyridin-4-yl-) methyleneamino] pyridine-3-ol (2-PMAP) using air $O_2$ and NaOCl oxidants at various temperatures and times in aqueous alkaline and acidic media. Under these reactions, the optimum reaction conditions using air $O_2$ and NaOCl oxidants were determined for 2-PMAP. The number-average molecular weight ($M_n$), weight average molecular weight ($M_w$), and polydispersity index (PDI) values of O-2-PMAP synthesized in aqueous alkaline media were found to be 960, 1230, and $1.281\;g\;mol^{-1}$ using NaOCl, and 1030, 1520, and $1.476\;g\;mol^{-1}$ using air $O_2$, respectively. At the optimum reaction conditions, the yield of O-2-PMAP in aqueous alkaline media was 92.50% and 85.70% for air $O_2$ and NaOCl oxidants, respectively. The yield of O-2-PMAP in aqueous acidic media was 88.5% and 88.0% for NaOCl and air $O_2$ oxidants, respectively. O-2-PMAP was characterized by $^1H-$, $^{13}C$-NMR, FT-IR, UV-vis, SEC, and elemental analysis. TGA-DTA analysis revealed O-2-PMAP and its oligomer metal complex compounds, such as $Co^{+2}$, $Ni^{+2}$, and $Cu^{+2}$, to be stable against thermal decomposition and their weight losses at $1000^{\circ}C$ were found to be 73.0, 58.0, 53.5%, and 50.0%, respectively. In addition, the antimicrobial activities of the monomer and oligomer were tested against E. Coli (ATCC 25922), E. Faecelis (ATCC 29212), P. Auroginasa (ATCC 27853), and S. Aureus (ATCC 25923).

• Korean Journal of Pharmacognosy
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• v.47 no.3
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• pp.211-216
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• 2016

In the course of our continuing search for biologically active components from Korean medicinal plants, we isolated the main compound, luteolin 5-glucoside from aqueous fraction of Ajuga spectabilis. The structure was elucidated by the basis of $^1H$ and $^{13}C$ NMR and TOF ESI-MS data. Quantitative analysis of luteolin 5-glucoside was carried out on a XBridge C18 column ($S-5{\mu}m$, $4.6{\times}250mm$) with gradient elution composed of acetonitrile:water. The results exhibit that the average content of main compound in A. spectabilis were 0.048%. Oxidative stress plays a major role Alzheimer's disease (AD) and other neurodogenerative disease. AD is major health problem and there is currently no clinically accepted treatment to cure or stop its progression. Pretreatment with luteolin 5-glucoside markedly attenuated $H_2O_2$-induced cell viability loss in a dose-dependent manner. Luteolin 5-glucoside also inhibited the formation of intracellular reactive oxygen species in SH-SY5Y. The results suggest that luteolin 5-glucoside from A. spectabilis has protective effects against oxidative stress-induced cytotoxicity, which might be a potential therapeutic compound for treating and/or preventing neurodegenerative disease implicated with oxidative stress.

• Journal of Life Science
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• v.20 no.3
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• pp.430-436
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• 2010

In this study, the effects of dibenzocyclooctadiene on seed germination were investigated in pepper. Four $C_{18}$ dibenzocyclooctadiene lignans - schisandrin (1143.7 mg), schisandrin C (317.3 mg), gomisin A (261.4 mg) and gomisin N (213.4 mg) - were isolated from hexane extracts of the fruits of Schisandra chinensis. The molecular structures of the four lignans were elucidated based on spectroscopic analyses including 1D NMR experiments, and bi comparing their spectroscopic data with those of previous literatures. Seeds were immersed in $10^{-5}\;M$ schisandrin, $10^{-6}\;M$ schisandrin C and $10^{-7}\;M$ gomisin A and gomisin N for 1 hr and incubated at $25^{\circ}C$ in the dark for germination. Compared to untreated control, treatment with schisandrin C and gomisin A suppressed seed germination at 48 hrs after incubation, whereas treatment with gomisin N increased germination rate at 48 hrs after incubation. The results of the germination activity of the lignans from S. chinensis confirm their potential plant growth role, and the relative natural abundances of these metabolites suggest their potential use as natural plant growth regulators.