• Journal of Ginseng Research
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• v.39 no.3
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• pp.221-229
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• 2015

Background: Minor ginsenosides, those having low content in ginseng, have higher pharmacological activities. To obtain minor ginsenosides, the biotransformation of American ginseng protopanaxadiol (PPD)-ginsenoside was studied using special ginsenosidase type-I from Aspergillus niger g.848. Methods: DEAE (diethylaminoethyl)-cellulose and polyacrylamide gel electrophoresis were used in enzyme purification, thin-layer chromatography and high performance liquid chromatography (HPLC) were used in enzyme hydrolysis and kinetics; crude enzyme was used in minor ginsenoside preparation from PPD-ginsenoside; the products were separated with silica-gel-column, and recognized by HPLC and NMR (Nuclear Magnetic Resonance). Results: The enzyme molecular weight was 75 kDa; the enzyme firstly hydrolyzed the C-20 position 20-O-${\beta}$-D-Glc of ginsenoside Rb1, then the C-3 position 3-O-${\beta}$-D-Glc with the pathway $Rb1{\rightarrow}Rd{\rightarrow}F2{\rightarrow}C-K$. However, the enzyme firstly hydrolyzed C-3 position 3-O-${\beta}$-D-Glc of ginsenoside Rb2 and Rc, finally hydrolyzed 20-O-L-Ara with the pathway $Rb2{\rightarrow}C-O{\rightarrow}C-Y{\rightarrow}C-K$, and $Rc{\rightarrow}C-Mc1{\rightarrow}C-Mc{\rightarrow}C-K$. According to enzyme kinetics, $K_m$ and $V_{max}$ of Michaelis-Menten equation, the enzyme reaction velocities on ginsenosides were Rb1 > Rb2 > Rc > Rd. However, the pure enzyme yield was only 3.1%, so crude enzyme was used for minor ginsenoside preparation. When the crude enzyme was reacted in 3% American ginseng PPD-ginsenoside (containing Rb1, Rb2, Rc, and Rd) at $45^{\circ}C$ and pH 5.0 for 18 h, the main products were minor ginsenosides C-Mc, C-Y, F2, and C-K; average molar yields were 43.7% for C-Mc from Rc, 42.4% for C-Y from Rb2, and 69.5% for F2 and C-K from Rb1 and Rd. Conclusion: Four monomer minor ginsenosides were successfully produced (at low-cost) from the PPD-ginsenosides using crude enzyme.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1349-1354
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• 2013

Twenty two new 5-fluorouracil (5-FU) derivatives, 2-butoxy-4-substituted 5-fluoropyrimidines, were synthesized and characterized by IR, $^1H$ NMR, MS, HRMS. All compounds were preliminarily evaluated by MTT assay on human liver BEL-7402 cancer cell line in vitro. Ten compounds were selected to test their cytotoxic activity against A549, HL-60 and MCF-7 cancer cell lines in vitro. These compounds were more sensitive to BEL-7402 than other cell lines, particularly, cytotoxic activity of compounds 6b, 6d-f, 6p, 6s-u were in sub-micromolar scale. The highest cytotoxic potency against A549, HL-60 and MCF-7 was shown by 2-butoxy-4-chloro-5-fluoropyrimidine (5) with $IC_{50}$ values of 0.10, 1.66 and $0.59{\mu}M$, respectively. Compounds 6d and 6e were effective against MCF-7 with $IC_{50}$ $9.73{\mu}M$ and HL-60 with $IC_{50}$ $8.83{\mu}M$, respectively.

• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.77-81
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• 2006

As a result of cytotoxic compounds against cancer cell lines from natural sources, senven compounds were isolated from the leaf and twig of Acer okamotoanum Nakai. The compounds (1-7) were identified as ethyl gallate (1), methyl gallate (2), gallic acid (3), trans $resveratrol-3-O-{\beta}-D-glucopyranoside$ (4), acertannin (5), nikoenoside (6), and fraxin (7) by physicochemical and spectroscopic data (including mp, UV, IR, MS, $^1H-NMR,\;^{13}C-NMR$, DEPT, and HMBC) in comparison with those of published papers. All the compounds were tested for their cytotoxic activity against L1210, HL-60, K562, and B16F10 cancer cell lines in vitro by MTT assay method. Compounds 1-3 and 5 showed cytotoxic activity against all tested cell lines with $IC_{50}$ values ranged from 12.5 to $72.2\;{\mu}M$. Of the compounds, methyl gallate (2) exhibited the most potent cytotoxic activity against L1210, HL-60, K562, and B16F10 tumor cells with $IC_{50}$ values of 12.5, 48.3, 22.8, and $22.8\;{\mu}M$, respectively. Other compounds did not show any cytotoxic activity against four cancer cell lines.

• Elastomers and Composites
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• v.46 no.4
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• pp.295-303
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• 2011

A series of new aromatic polyhydroxyamides (PHAs) containing imide ring were prepared by direct polycondensation reaction of imide-diacids and two types of bis(o-aminophenol)s including 3,3'-dihydroxybenzidine and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane. The polymers were characterized by FT-IR, FT-NMR, DSC and TGA. The inherent viscosities of the PHAs measured at $35^{\circ}C$ in DMAC solution were in the range of 0.49-1.13 dL/g. PHA 2 and 3, except PHA 1, were soluble in polar solvents such as DMAc, DMF and NMP. PHA 4, 5, and 6 containing 6F group showed a higher solubility in less polar solvents. But the polybenzoxazoles (PBOs,) were insoluble in a variety of solvents except partially soluble in sulfuric acid. The PBO 1, 2 and 3 showed maximum weight loss temperature in the range of $650-656^{\circ}C$ and relatively high char yields in the range of 57.4-61.9 % under a nitrogen atmosphere. These results suggested that the introduction of imide or diimide ring in the main chain was effective in improving the thermal stability of PHAs and PBOs.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.820-826
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• 1996

The p2H dependence of the NMR chemical shifts of the proton signals of heme methyl groups and ionizable groups in the vicinity of the heme were investigated. The p2H titration of heme methyl signals in four macroscopic oxidation states by saturation tranfer method was performed in the range between p2H 5.2 and 9.0. While the p2H dependence of the heme methyl resonance in fully oxidized state was small, most resonances in the intermediate oxidation states showed certain shifts. Particularly, methyl resonances of heme 1 (sequential heme numbering) exhibited sharp p2H dependence in acidic range. β-CH2 of the propionate of hemes 1 and 4 were titrated in the range of p2H 4.5-9.0. Only the 6-propionate group of heme 1 was protonated in this p2H range and its titration curve was similar to those of methyl resonances of heme 1 in intermediate oxidation states. Analysis of the microscopic redox potentials showed that they change depending on p2H. The ionizable groups responsible for the p2H dependence of these potentials are 6-propionate of heme 1 in acidic range and His 67 in basic range.

• Journal of Life Science
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• v.16 no.5
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• pp.794-798
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• 2006

A tomato (Lycopersicon esculentum cv. Naomi F1) juice was separated into ascorbate and phenolic portions using a Sep-pak $C_{18}$ cartridge, and its each portion was tested for inhibition of N-nitrosodimethylamine (NDMA) formation. Ascorbate and phenolic portions of tomato juice inhibited NDMA formation by $81.37{\pm}0.25%$ and $72.03{\pm}0.25%$, respectively. The phenolic portion was further fractionated by prep-HPLC and inhibitory effects of NDMA formation by 4 fractions $(1{\sim}4)$ from tomato juice was tested under the different pH conditions (pH 1.2 and 4.2). Fraction 2 inhibited NDMA formation by $50.10{\pm}0.46%$ (pH 1.2) and $64.30{\pm}0.20%$ (pH 4.2), respectively. Fraction 2 was further separated into 4 subfractions $(2a{\sim}2d)$. Subfraction 2b especially inhibited NDMA formation by $70.62{\pm}0.45%$ (pH 1.2) and $75.30{\pm}0.45%$ (pH 4.2). This subfraction was confirmed o-coumaric acid through the analysis of GC-Mass spectrum, $^1H-NMR$ and $^{13}C-NMR$.

• Microbiology and Biotechnology Letters
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• v.49 no.1
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• pp.24-31
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• 2021

This study aimed to investigate the melanogenesis inhibitory activity of epicatechin-3-O-gallate (ECG) isolated from Polygonum amphibium L. ECG was isolated from the ethanol extract of P. amphibium L, and its chemical structure was determined using spectroscopic methods such as LC-ESI-MS, 1D-NMR, and UV spectroscopy. ECG inhibited the melanogenesis of B16F10 cells in a dose-dependent manner. Particularly, it decreased the melanin content by 27.4% at 200 µM concentration, compared with the control, in B16F10 cells, without causing cytotoxicity. It is noteworthy that the expression of three key proteins, including tyrosinase, tyrosinase-related protein-1 (TRP-1), TRP-2, and microphthalmia-associated transcription factor (MITF), involved in melanogenesis, is significantly inhibited by ECG. The ECG isolated in this study caused the inhibition of body pigmentation and tyrosinase activity in vivo in the zebrafish model. These results suggest that the ECG isolated from P. amphibium L. is an effective anti-melanogenesis agent.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.1
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• pp.53-60
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• 2017

In this study, we investigated whitening and anti-inflammatory constituents from a watermelon (Citrullus lanatus, C. lanatus) vines (leaves and stems). As anti-melanogenesis and anti-inflammatory activities were screened for the ethanol extract and solvent fractions, n-hexane (n-Hex) and ethyl acetate (EtOAc) fractions showed the most potent activities. Three constituents were isolated from the n-Hex and EtOAc fractions of C. lanatus; ${\alpha}-linolenic$ acid (1), sigmast-7-en-O-${\beta}$-D-glucopyranoside (2), 1-feruloyl-${\beta}$-D-glucopyrinoside (3). The chemical structures of the isolated compounds were elucidated based on the spectroscopic data including $^1H$ and $^{13}C$ NMR spectra, as well as comparison of the data to the literature values. Whitening and anti-inflammatory effects were studied for the isolated compounds. Upon the anti-melanogenesis tests using ${\alpha}-MSH$ stimulated B16F10 melanoma cells, the compounds 1 and 3 inhibited the cellular melanogenesis and intracellular tyrosinase activities effectively. For the anti-inflammation tests using lipopolysaccharide (LPS)-induced RAW 264.7 cells, the isolates 1 and 3 were determined to decrease the production of nitric oxide (NO) and pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6). Based on these results, C. lanatus vines extract could be potentially applicable as whitening and anti-inflammatory ingredients in cosmetic formulations.

• Bulletin of the Korean Chemical Society
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• v.14 no.5
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• pp.546-548
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• 1993

The discrete structure of substituted 9-benzonorbornenyl cation 3a and 3c was studied using the empirical ${\Delta}$J equation which was developed by Kelly and coworker$^5$. The ${\Delta}$J values of substituted 9-benzonorbornenyl cations were obtained from p-methyl-6,7-dimethyl benzonorbornen-9-yl (3a) and 9-methyl-6,7-dimethyl benzonorbonen-9-yl (3c) cations under stable ion conditions, and were compared with those of the corresponding ketone analog; these cations were generated by dissolving the corresponding carbinols in superacid at -120$^{\circ}$C and the nmr spectra taken at -60$^{\circ}$C~-90$^{\circ}$C. The ${\Delta}$J values are 8.7 Hz for the bridgehead carbons in cation 3c and 3.1 Hz for cation 3b. The ${\Delta}$J values at C5,8 in fused benzene ring are 14.3 Hz for cation 3c and 8.7 Hz for cation 3a. The excellent correlation of the ${\Delta}$J values with 1$^9F$ chemical shifts of p-fluorophenyl-6,7-dimethylbenzonorbornenyl cation (3d) indicate that ${\Delta}$J value is a reliable probe to charge density at adjacent cationic carbon. These NMR parameters strongly support that the symmetrically ${\pi}$-bridged nonclassical structure (type 2) of substituted 9-benzonorbornenyl cations in stable ion conditions.

• Applied Biological Chemistry
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• v.39 no.6
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• pp.501-505
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• 1996

우리나라에서 오랫동안 적색 및 황색색소원으로 널리 사용하여 왔던 홍화(Carthamus tinctorius)로부터 전통적인 추출방법을 응용한 새로운 방법을 사용하여 적색소를 효과적으로 분리정제하였다. 홍화꽃잎을 물 및 메탄올로 처리하여 황색소를 제거한 다음 건조파쇄하여 0.5 M $Na_2CO_3$로 홍색소를 추출하고 0.5 M citrate 수용액으로 침전시킨 후 cellulose 흡착, Sephadex LH-20 관크로마토그라피로 분리정제하였다. 분리정제된 적색소는 $300^{\circ}C$에서 분해되었고 silica gel TLC 상에서 BAW(n-BuOH : HOAc : $H_2O$=4 : 1 : 5)로 전개하였을 때 $R_f$값이 0.56이었다. 에탄올 용액에 녹인 적색소의 UV/Vis 흡수스펙트럼은 519, 372, 311, 244 nm에서 최대 흡수피크를 나타내었고, IR 스펙트럼은 특히 $3400\;cm^1$ 넓은 영역에서 hydroxyl기에 의한 강한 흡수띠를 보여주었다. $^{1}H$ 및 $^{13}C$ NMR data로 부터 enolized ${\beta}-triketone$, p-hydroxycinnamoyl, methine 및 glucosyl moieties를 확인하였고 그 값을 제시하였다. 이상의 data를 문헌과 비교한 결과 분리한 홍화적색소의 화학구조는 $6-{\beta}-D-glucopyranosyl-2-[[3-{\beta}-D-glucopyranosyl-2,3,4-trihydroxy-5-[3#-(4@-hydroxyphenyl)-1#-oxo-2#-propenyl]-6-oxo-1,4-cyclohexadien-1-yl]methylene]-5,6-dihydroxy-4-[3#-(4@-hydroxyphenyl)-1#-oxo-2#-propenyl]-4-cyclohexene-1,3-dione$인 carthamin으로 확인하였다.