• Macromolecular Research
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• v.14 no.2
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• pp.209-213
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• 2006

The ring-opening polymerization of D,L-lactide initiated by tin(II) 2-ethylhexanoate $(Sn(Oct)_2)$ on the surface-initiated magnetite $(Fe_{3}O_4)$ nanoparticles was performed at $130^{\circ}C$. The effects of the polymer molar mass and concentration on the amount of surface polymer were investigated. The number average molecular weights, $M_n$, obtained by both NMR and GPC methods fit well within the accuracy of the applied methods and ranged from 1,100 to $4,040g\;mol^{-1}$. A surface functionalization density of up to 625 initiation sites per particle was obtained. The composition of various core-shell particles was determined by TGA, with results indicating magnetite $(Fe_{3}O_4)$ contents, ${\mu}m$, between 17 and 59 wt%. Under the influence of a magnetic field, the heating generated by superparamagnetic core-shell particles suspended in toluene presented guidelines for an optimization of magnetic particle systems with respect to an application for hyperthermia.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.300-304
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• 2004

Five caffeic acid derivatives; methyl ester of caffeoylglycolic acid (1), dimethyl ester of caffeoyltartaric acid (2), dimethyl ester of caffeoyltartronic acid (3), monomethyl ester of caffeoyltartronic acid (4), methyl ester of caffeic acid (5), and some other secondary metabolites including; quercetin, quercetin 3-O-$\beta$-D-glucuronide methyl ester, kaempferol, 3,5,7,4'-O-tetramethylkaempferol, $\beta$-sitosterol glucoside, 2$\alpha$-hydroxyursolic acid and 2,24-dihydroxyursolic acid, have been isolated and characterized. All the isolated compounds were characterized with the help of NMR spectroscopy and mass spectrometry. Structure of compound 3 was also confirmed by a single X-ray crystallographic technique. Isolates were evaluated for anti-oxidant activities and most of the tested compounds were found to be potent in DPPH free radical scavenging ($IC_{50}{\;}={\;}4.56-14.17{\;}{\mu\textrm{g}}/mL$) and superoxide anion scavenging ($IC_{50}{\;}={\;}0.58-7.39{\;}{\mu\textrm{g}}/mL$) assays.

• Natural Product Sciences
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• v.18 no.2
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• pp.97-101
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• 2012

Six lignan compounds, 1-(17,21-dihydroxyphenyl)-9-(12,13-dihydroxyphenyl)-1-nonanone (malabaricone C) (1), 7'-(3',4'-methylenedioxyphenyl)-8,8'-dimethyl-7-(3,4-dihydroxyphenyl)-butane (2), 7'-(3',4'-dimethoxyphenyl)-8,8'-dimethyl-7-(3-methoxy-4-hydroxyphenyl)-butane (3), 7-(4-hydroxy-3-methoxyphenyl)-7'-(3',4'-methylenedioxyphenyl)-8,8'-lignan-7-methyl ether (4), (+)-erythro-(7S,8R)-${\Delta}^{8^'}$-7-hydroxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan (5), and (+)-erythro-(7S,8R)-${\Delta}^{8^'}$-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan (6), were isolated from the seeds of Myristica fragrans. The chemical structures of these compounds were determined on the basis of spectroscopic analyses including 2D NMR. Compounds 1 - 6 were evaluated for their cytotoxic activity against the HL-60, MCF-7, and A549 cancer cell lines in in vitro.

• Natural Product Sciences
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• v.17 no.3
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• pp.183-188
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• 2011

A bisdesmosidic cholestane glycoside was isolated from the rhizomes of Polygonatum sibiricum and the structure was elucidated by spectroscopic methods and acid hydrolysis as (22S)-cholest-5-ene-$1{\beta}$,$3{\beta}$,$16{\beta}$,22-tetrol 1-O-${\alpha}$-L-rhamnopyranosyl 16-O-${\beta}$-D-glucopyranoside. This compound exhibited weak cytotoxic activity with the $IC_{50}$ value, $63.6\;{\mu}M$ in human MCF-7 breast cancer line, whereas it failed to show agonistic activity at $100{\mu}M$ in TGR5 assay with Chinese hamster ovary (CHO) cells. This is the first report of a bisdesmosidic cholestane glycoside from Polygonatum species and the full assignments of $^1H$, $^{13}C$ NMR by HMBC, TOCSY and NOESY experiments were provided.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.85-88
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• 1997

In orther to isolate antibacterial substances from the flower of Chrysanthemum zawadskii Herbich var. latilobum Kitam., the chloroform fraction was fractionated according to the activity against B. subtilis, S. aureus and V. parahaemolyticus. Two antibacterial substances were isolated and purified by preparative TLC and recrystallization. Compound I showed activity against all the tested bacteria and compound II exhibited the activity against B. subtilis and v. parahaemolyticus except S. aureus. Compared to benzoic acid and sorbic acid which are being used as food preservatives, compounds I and II showed about five-fold stronger antibacterial activity against B. subtilis and V. parahaemolyticus. On the basis of spectrometric studies including $^1H-NMR,\;^{13}C-NMR,\;DEPT,\;^1H-^1H\;COSY,\;^{13}C-^1H\;COSY$ and Mass, compounds I and II were identified as angeloylcumambrin B and cumambrin A, respectively. This is the first report of the isolation of angeloylcumambrin B and cumambrin A from this plant.

• Analytical Science and Technology
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• v.13 no.2
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• pp.173-178
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• 2000

A new open-chain ligand containing two phenol groups, 1, 14-Bis (2-hydroxybenzyl)-2, 6, 9, 12-tetraazatetradecane(bsated) was synthesized as its tetrahydrochloride salt and characterized by elemental analysis, mass, infrared and NMR. Its proton dissociation constants ($logK^n{_H}$) and stability constants ($logK_{ML}$) toward $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$ and $Zn^{2+}$ were determined at $25^{\circ}C$ and 0.10M($KNO_3$) ionic strength in aqueous solution by potentiometry. The X-ray structure of its copper (II) complex [Cu(bsated)]$(ClO_4)_2$ was reported: Monoclinic space group $P2_1/n$, $a=17.856(4){\AA}$, $b=17.709(1){\AA}$, $c=8.539(2){\AA}$, $V=2700(2){\AA}$ with Z=4. Electrochemical studies of [Cu(bsated)]$(ClO_4)_2$ complex in dimethyl sulfoxide (DMSO) solution containing tetrabutylammonium perchlorate (supporting electrolyte) were carried out by cyclic voltammograms (CV) and normal pulse voltammetry (NPV).

• Bulletin of the Korean Chemical Society
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• v.15 no.5
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• pp.394-399
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• 1994

The catalytic mechanism of malonyl-CoA synthetase from Rhizobium trifolii was investigated by the steady state kinetics and intermediate identification. Initial velocity studies and the product inhibition studies with AMP and PPi strongly suggested ordered Bi Uni Uni Bi Ping-Pong Ter Ter system as the most probable steady state kinetic mechanism of malonyl-CoA synthetase. Michaelis constants were $0.17{\pm}0.04 {\mu}M,\;0.24{\pm}0.18 {\mu}M\;and\;0.045{\pm}0.26 {\mu}$M for ATP, malonate and CoA, respectively. The TLC analysis of the $^{32}P-labelled$ products in reaction mixture containing $[{\gamma}-^{32}P]$ ATP in the absence of CoA showed that PPi was produced after the sequential addition of ATP and malonate. Formation of malonyl-AMP, suggested as an intermediate in the kinetically deduced mechanism, was confirmed by the analysis of $^{31}P-NMR$ spectra of AMP product isolated from the $^{18}O$ transfer experiment using $[^{18}O]$malonate. Two resonances were observed, corresponding to AMP labelled with zero and one atom of $^{18}O$, indicating that one atom of $^{18}O$ transferred from $[^{18}O]$malonate to AMP through the formation of malonyl-AMP. Formation of malonyl-AMP was also confirmed through the TLC analysis of reaction mixture containing $[{\alpha}-^{32}P]$ATP. These results strongly support the ordered Bi Uni Uni Bi Ping-Pong Ter Ter mechanism deduced from the initial velocity and product inhibition studies.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.309-315
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• 2009

In our search for the natural cosmetic ingredients, we found that Euryale ferox seed extract exhibited the strong antioxidative activity. Five active compounds were isolated from the ethyl acetate extract through various chromatographic methods and their structures were determined by NMR and MS spectral analysis. These compounds were identified as fucosterol (1), 3-(4-hydroxy-3-methoxybenzyl)-4-[(7'R),5'-dihydroxy-3'-methoxybenzyl]tetrahydrofuran (2), resorcinol (3), pyrogallol (4) and 4-O-methylgallic acid (5).We evaluated the antioxidative, antielastase activities and melanogenesis inhibitory effects of these compounds. The $SC_{50}$ values of compounds 2 ~ 5 for free radical scavenging activity were $17.0\;{\sim}\;100.2\;{\mu}M$ and especially compounds 4 and 5 were 6-fold more effective than ferulic acid as a positive control. And compounds 2 ~ 4 inhibited human neutrophil elastase with $IC_{50}$ values of $18.8\;{\sim}\;78.2\;{\mu}M$ and compound 3 also inhibited melanin synthesis in B16F10 melanoma cells with an $IC_{50}$ value of $492.8\;{\mu}M$. These results suggest that Euryale ferox extract having a lot of various active ingredients may be useful as a natural multi-functioning agent.

• Applied Biological Chemistry
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• v.41 no.5
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• pp.390-394
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• 1998

The tuber of Liriope platyphylla was extracted with 80% aqueous MeOH and solvent-fractionated with EtOAc, n-BuOH and $H_2O$. Evaluation of growth inhibitory activity of each fractions on various carcinoma cells, A549, SK-OV-3, SK-Mel-2, XF-498 and HCT-15, indicated the n-BuOH fraction to be the highest in the activity. From the fraction, two saponin compounds were isolated through Amberlite XAD-II and silica gel column chromatographies, repeatedly, and their chemical structures were elucidated as spicatoside A and B by interpretation of spectral data, NMR and IR, and adaptation of acid hydrolysis. Spicatoside A showed growth inhibitory activity on carcinoma cells, and the $IC_{50}$ values against A549, SK-OV-3, SK-Mel-2, XF-498 and HCT-15 cells were determined to be 17.3, 21.7, 14.9, 18.8 and $15.6\;{\mu}g/ml$, respectively.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.620-630
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• 2003

The proliferative effects of thirty Oriental medicinal herbs on MCF-7 (estrogen-sensitive breast cancer cell line) and ROS 17/2.8 osteoblast-like cells were determined using the MTT assay. Methanol extracts from several herbs was found to show proliferative activity on the above two cell lines in the range of 5 to 100 $\mu$g/mL. Among these active herbs, the methanol extract from the rhizomes of Drynaria fortunei showed the most potent proliferative activity, and the cell proliferations were significantly increase by 136 and 158% in the MCF-7 and ROS 17/2.8 cells, respectively, when treated with 100 $\mu$ g/mL. Through a bioassay-guided separation, eight flavonoids, including four new flavan-3-ols and two propelargonidins, together with the known (-)-epiafzelechin and naringin, were isolated. Their chemical structures were characterized as (-)-epiafzelechin (1), (-)-epiafzelechin-3-O-$\beta$-D-allopyranoside (2), (-)-epiafzelechin-3-O-(6"-O-acetyl)-$\beta$-D-allopyranoside (3), 4$\beta$-carboxymethyl-(-)-epiafzelechin methyl ester (4), 4$\beta$-car-boxymethyl-(-)-epiafzelechin sodium salt (5), naringin (6), (-)-epiafzelechin-(4$\beta$\rightarrow8)-4$\beta$-car-boxymethylepiafzelechin methyl ester (7) and (-)-epiafzelechin-($4\beta\rightarrow8, 2\beta\rightarrowΟ\rightarrow7)-epiafzelechin-(4\beta\righarrow8)-epiafzelechin (8) by extensive 1D and 2D NMR spectroscopy. Most of these flavonoids, in the range of $10^{-15}∼10^{-6}$ M, accelerated the proliferation of MCF-7 cell, with compounds 7 and 8, in the range of $10^{-15}∼10^{-12}$ M, showing especially potent proliferation effects. Meanwhile, seven flavonoids, with the exception of compound 4, stimulated the proliferation of ROS 17/2.8 cells in the range of $10^{-15}∼10^{-6}$ M, with compounds 5-8 especially accelerating the proliferation, in dose-dependent manners ($10^{-15}∼10^{-9}$ M), and their proliferative effect was much stronger than that of $E_2$ and genistein. These results suggest that propelargonidin dimers and trimers isolated from the rhizomes of Drynaria fortunei may be useful as potential phytoestrogens, which play important physiological roles in the prevention of postmenopausal osteoporosis.