• Polymer(Korea)
• /
• v.39 no.1
• /
• pp.13-22
• /
• 2015

A new methacrylate copolymer that includes chalcone as a side group, poly(4-methacryloyloxyphenyl-4'-methoxystyryl ketone-co-styrene) was synthesized by free radical copolymerization. FTIR and $^1H$ NMR spectroscopic techniques were used to characterize the homopolymers and copolymers. The copolymerizations were carried out to high conversions. Copolymer compositions were established by $^1H$ NMR spectra analysis. The monomer reactivity ratios for copolymer system were determined by the linearized Kelen $T{\ddot{u}}d{\ddot{o}}s$, and Extended Kelen $T{\ddot{u}}d{\ddot{o}}s$ methods and a non-linear least squares method. The molecular weights and polydispersity index of copolymers were measured by using the gel permeation chromatography (GPC). The effect of copolymer compositions on their thermal behavior were studied by differential scanning calorimetry and thermogravimetric analysis methods. The optical properties of the resulting copolymer were also investigated.

• Journal of the Korean Chemical Society
• /
• v.55 no.2
• /
• pp.256-261
• /
• 2011

A new series of bis acetylated hybrid pyrazoles were synthesized and characterized by their melting point, elemental analysis, MS, FT-IR, one-dimensional $^1H$, and $^{13}C$ NMR spectroscopic data. All the synthesized compounds were tested for their in vitro antifungal activities against Candida sp. namely Candida albicans, Candida glabrata, Candida parapsilosis, Candida dubliniensis and Candida tropicalis. A close inspection of the in vitro anticandidal activity profile in differently electron donating ($CH_3$ and $OCH_3$) and electron withdrawing (-F, -Cl, and Br) functional group substituted phenyl rings of novel hybrid pyrazoles exerted strong anticandidal activity against all the tested Candida species.

• Polymer(Korea)
• /
• v.31 no.2
• /
• pp.153-159
• /
• 2007

Biodegradable molecularly imprinted polymers (MIPs) can be applied in the biomedical area of biosensors, drug delivery, etc. Therefore, in this study, biodegradable theophylline MIPs were synthesized via photopolymerization using a poly $(\varepsilon-caprolactone)$ (PCL) macromer as a cross-linker and their physical properties were investigated. The yield for the synthesis of the PCL macromer with terminal acrylate groups was ca. 78 mol%. The products were characterized by the combination of FT-IR and $^1H-NMR$ spectroscopic analyses. UV/Visible spectroscopic analysis for removing and rebinding theophylline was performed by monitoring the theophylline concentration in the solution. In vitro biodegradation tests of the theophylline MIPs performed in phosphate buffered saline (PBS) solution at $37^{\circ}C$ showed good biodegradability of the MIPs.

• Journal of Ginseng Research
• /
• v.32 no.4
• /
• pp.291-299
• /
• 2008

The fresh ginseng roots were extracted in aqueous methanol (MeOH), and the obtained extracts were partitioned using ethyl acetate (EtOA), n-butanol (n-BuOH), and water, successively. The repeated silica gel column chromatography for n-BuOH fraction afforded a purified ginsenoside $Rg_1$. The physico-chemical, spectroscopic and chromatographic data of ginsenoside $Rg_1$, such as crystallization characteristics, melting point, specific rotation, infrared spectrometry (IR) data, fast atom bombardment/mass spectrometry (FAB/MS) data, nuclear magnetic resonance (NMR) data, retention factor (Rf) in thin layer chromatography (TLC) experiment, and retention time (r.t.) in HPLC analysis, were measured and compared with those reported in literatures. Especially, the previous literatures reported different data for ginsenoside $Rg_1$ in the $^{1}H-$ and $^{13}C$-NMR experiments. This paper gives the exactly assigned NMR data through 2D-NMR experiments, such as $^{1}H-^{1}H$ correlation spectroscopy (COSY), hetero nuclear single quantum correlation (HSQC), and hetero nuclear multiple bond connectivity (HMBC).

• Applied Chemistry for Engineering
• /
• v.19 no.1
• /
• pp.133-136
• /
• 2008

In order to decrease carbon dioxide, one of the green house gas, poly(styrene carbonate) has been synthesized from carbon dioxide and styrene oxide with zinc glutarate as a catalyst. The polymer has been identified as an alternating copolymer by spectroscopic analysis, FT-IR, $^1H$-NMR, and $^{13}C$-NMR. The number average molecular weight ($M_n$) of the polymer is $5.0{\times}10^4g/mol$ and the glass transition temperature ($T_g$) is $88^{\circ}C$ and its melting point ($T_m$) is $240^{\circ}C$. The cyclic carbonate, styrene carbonate, has been obtained by thermal degradation of the polymer via the unzipping mechanism.

• The Korean Journal of Food And Nutrition
• /
• v.11 no.3
• /
• pp.347-353
• /
• 1998

An antibiotic for methicillin resistant Staphylococcus aureus(MRSA) produced by Streptomyces lydicus YSK-681 was extracted by chloroform, and then purified by the C18 reversed-phase HPLC and silica gel column HPLC. The molecular weight of the purified antibiotic was determined from the FAB analysis MS an m/z 1022.4 and 1036.4(M+H)+, indicating that the isolated antibiotic consisted of two similar compounds with the molecular weight difference of 14 m/z value. With the aid of the various nuclear magnetic resonance(NMR) spectroscopic techniques such as 1H NMR, 13C NMR, DEPT and HMQC spectroscopy, the characteristics of function al groups were deduced as the hydroxyl group and leucine. The MIC values of the purified antibiotic were observed at 1∼32 $\mu\textrm{g}$/$m\ell$ against Gram-positive bacteria compared to > 125 $\mu\textrm{g}$/$m\ell$ against Gram-negative bacteria or fungi. The antibiotic was active at 8 $\mu\textrm{g}$/$m\ell$ of MIC90 and S180 at the concentration of 500 $\mu\textrm{g}$/$m\ell$.

• Natural Product Sciences
• /
• v.20 no.3
• /
• pp.206-210
• /
• 2014

Phytochemical constituents were isolated from Pinus koraiensis needles by open column chromatography. The structures isolated from the ethyl acetate fraction of P. koraiensis needles were elucidated as afzelin (1) and quercitrin (2) on the basis of spectroscopic analyses including $^1H$-NMR and MS. The amounts of afzelin (1) and quercitrin (2) in genus Pinus were determined by HPLC/UV analysis. Afzelin (1) and quercitrin (2) contents were highest in P. thunbergii needles. Because P. thunbergii needles contain high amounts of afzelin (1) and quercitrin (2), they have promising potential as new additives to natural medicinal products, health supplements, and beverages.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.6
• /
• pp.889-894
• /
• 2004

Polyaddition reactions of 1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene with several organoborane derivatives have afforded the oligomeric materials containing organosilacyclic group and organoboron moiety along the oligomer main chains. All of these materials are soluble in THF as well as chloroform, and their molecular weights are in the range of 1,990/1,190-21,950/7,050 ($M_w/M_n$) with the polydispersity indexes of 1.67-3.43. The prepared oligomers are characterized by several spectroscopic methods such as $^1H,\;^{13}C, \;^{29}Si,\;^{11}B$ NMR and FTIR spectra along with elemental analysis. FTIR spectra of all the oligomers show that the new strong C=C stretching frequencies appear at 1599-1712 $cm^{-1}$, in particular. The UV-vis absorption spectra of the materials in THF solution exhibit the strong absorption bands at the ${\lambda}_{max}$ of 268-275 nm. The oligomeric materials show that the strong excitation peaks appear at the ${\lambda}_{max}$ of 255-279 nm and the strong fluorescence emission bands at the ${\lambda}_{max}$ of 306-370 nm. All the spectroscopic data suggest that the obtained materials contain both the organoboron ${\pi}$-conjugation moiety of C=C-B-C=C and the organosilacyclic group of 3-triethylsilyl-1-silacyclopent-3-ene along the oligomer main chains. The oligomers are thermally stable up to 162-200 $^{\circ}C$ under nitrogen.

• Journal of the Korean Chemical Society
• /
• v.51 no.4
• /
• pp.339-345
• /
• 2007

Urea reacts with PtCl2, H2[PtCl6]·6H2O, H2[IrCl6] and Ni(CH3CO2)2 in aqueous solution at high temperature (60-80 °C) yielding [PtCl2(Urea)]·2H2O (1), (NH4)2[PtCl6] (2), (NH4)2[IrCl6]·H2O (3) and [Ni2(OH)2(NCO)2(H2O)2] (4) complexes, respectively. In complex 1, urea coordinates to Pt(II) as a neutral bidentate ligand via amido nitrogen atoms. In complexes 2, 3 and 4 it seems that the coordinated urea molecules decompose during the reaction at high temperature and a variety of reaction products are obtained. All complexes were isolated in moderate yields as dark green (1), yellow (2), pale brown (3) and faint green (4) precipitates, respectively. The reaction products were characterized by their microanalysis, IR, 1H and 13C NMR spectra as well as thermal analysis. General mechanisms describing the formation of these complexes were suggested.

• Journal of the Korean Chemical Society
• /
• v.54 no.1
• /
• pp.49-54
• /
• 2010

A new series of novel 2-morpholino-N-(4,6-diarylpyrimidin-2-yl)acetamides 34-42 is synthesized by the condensation of 2-chloro-N-(4,6-diarylpyrimidin-2-yl)acetamides 25-33 with morpholine in the presence of anhydrous potassium carbonate. The synthesized compounds have been characterized by melting point, elemental analysis, MS, FT-IR, one-dimensional NMR ($^1H$ & $^{13}C$) spectroscopic data.