• Mass Spectrometry Letters
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• v.4 no.2
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• pp.30-33
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• 2013

Chalcones are naturally occurring, biologically active molecules generating interest from a wide range of research applications including synthetic methodology development, biological activity investigation and studying fragmentation patterns. In this article, a series of chalcones has been synthesized and their fragmentation behavior was studied using modern ambient ionization technique Direct Analysis in Real Time (DART). DART ion source connected with an ion trap mass spectrometer was used for the fragmentation of various substituted chalcones. The chalcones were introduced to the DART source using a glass capillary without sample preparation step. All the chalcones showed prominent molecular ion peaks $[M]^{{\cdot}+}$ corresponding to the structures. Multistage mass spectral data $MS^n$ ($MS^2$ and $MS^3$) were collected for all the chalcones studied. The chalcones with substitutions at 3, 4 or 5 positions gave product ion peaks with the loss of a phenyl radical ($Ph^{\cdot}$) by radical initiated ${\alpha}$-cleavage, while substitution at 2 position of chalcone in the A-ring gave a product ion peak with the loss of substituted styryl radical (PhCH = $CH^{\cdot}$). In case of the chalcones with the substituent at 4 positions in A and B rings gave both types of fragmentation patterns. In conclusion, chalcones can be easily characterized using modern DART interface in very short time and efficiently without any cumbersome sample pretreatment.

• Journal of the Korean Chemical Society
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• v.20 no.3
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• pp.229-235
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• 1976

Phenylacetic acid is chlorinated photochemically in carbon disulfide and carbon tetrachloride solvents to obtain ${\alpha}$-chlorophenylacetic acid in $43{\%}$ yield (after separation and purification). The amination of ${\alpha}$-chlorophenylacetic acid yielded the desired dl-phenylglycine in $16\sim27{\%}$ yield depending on the solvent used. Sensitized photophenylation of glycine is also attempted utilizing benzoylperoxide as a phenyl radical source in benzene or acetone solvent.

• Journal of the Korean Applied Science and Technology
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• v.4 no.2
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• pp.19-23
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• 1987

The addition of dipeptides and 1,2-bis (aminoacyl) hydrazine derivatives a level of 250 ppm to corn oil resulted in the retardation of the oxidaitive deterioration of the oil when it was stored in the oven at $70^{\circ}C$ during 5 days. Their antioxidant activities were investigated by UV absorbance of the corn oil at the wavelength of 234nm. 1,2-bis (aminoacyl) hydrazine derivatives showed higher antioxidant activity than normal dipeptides. Dipeptides containing phenyl ring with which is conjugable a-carbon radical showed antioxidant activity.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.95-96
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• 2006

Surface modification of clay minerals has become increasingly important for improving the practical applications of clays such as polymeric nanocomposites. We used the copolymer as modifiers having phenyl components, and successfully developed a route for the preparation of amine functionalized polymer based on oligostyrene and its block copolymers. The oligo(St-co-VBC)s with controlled molecular weight were synthesized via nitroxide mediated polymerization method. We also successfully prepared organophilic layered silicates whose surface is covered with styrenic copolymers. Through the analysis of chemical structure and morphology, we concluded that copolymers were very effective organic modifiers to change the surface characteristics of layered silicates.

• Journal of Information Display
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• v.11 no.3
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• pp.95-99
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• 2010

A series of new dielectric polymers with phenyl, epoxy, and carboxylicacid functional groups was prepared via free-radical polymerization. The effect of such dielectric polymers with various functional groups on the performance of OTFT was investigated. The nonpolar groups of terpolymer made the surface of the dielectric layer more hydrophobic and improved the crystal growth of pentacene on the gate insulator, resulting in higher mobility. By controlling the functional group, the electric characteristics of OTFT performance was varied, with $0.00017-0.15\;cm^2/V{\cdot}s$ mobility.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1809-1813
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• 2003

Monomeric antioxidant 1 was prepared by the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with N-[4-(chlorocarbonyl)phenyl]maleimide in the presence of imidazole. Monomeric antioxidant 2, bearing carbamate group, was synthesized from the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and azidomaleimide. Antioxidant 3 was prepared by the reaction of N-(4-hydroxyphenyl)maleimide and 3-(3,5-ditert-butyl-4-hydroxyphenyl) propionic chloride in the presence of triethylamine. These reactive antioxidants were grafted onto polypropylene (PP) by melt-processing with free radical initiators in a mini-max moulder. From the infrared spectra of the grafted PP, it was found that the monomeric antioxidants were grafted onto PP. IR spectroscopic methods were used for the quantitative determination of the extent of grafting of monomeric antioxidant. To optimize the reaction conditions, the influences of the concentration of DCP, monomeric antioxidant, reaction time and temperature on the extent of grafting were studied.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.619-623
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• 1999

$2^{l},3^{l}$-dideoxyisoguanosine was synthesized from guanosine via intermediate 6-[(4-methyl-phenyl)thio]-2-oxo-9-($2^{l},3^{l},5^{l}$-tri-O-acetyl-$\beta$-D-ribofuranosyl)-2,3-dihydropurine (4). The 2-oxo, 6-amino and $5^{l}$-hydroxy triprotected isoguanosine derivative was utilized to reduce high polarity and promote poor solubility of intermediates. The protecting groups for oxo and 6-amino were easily removed in reduction of olefin in ribose without additional reaction steps.$2^{l},3^{l}$-Vicinal diol in ribose sugar moiety was transformed to olefin with Bu3SnH by radical reaction via bisxanthate. Removing $5^{l}$-O-TBDMS protecting group gave final product, $2^{l},3^{l}$-dideoxyisoguanosine (12) in a 10% overall yield.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.2
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• pp.306-310
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• 2011

Elastic fibers are found in the skin, lungs, arteries, veins and other structures. Elastases destroy the elastic fibers and cause the emphysema and pulmonary hypertension. Oxidative stress is needed for these pathologic changes. Accordingly, present study was designed to investigate the effect of Albizziae Cortex extracts (ACE) on elastase activity and anti-oxidative effects of ACE. The in vitro inhibitory effects on elastase and di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) and nitric oxide (NO) free radical scavenging activities of ACE were measured. The elastase activity was significantly inhibited by ACE. DPPH and NO free radicals were significantly scavenged as well. ACE showed the elastase-inhibiting effects and anti-oxidative activities in vitro. These results suggest that ACE may have potential roles in the treatment of pulmonary emphysema and pulmonary hypertension.

• Journal of Korea Foresty Energy
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• v.23 no.1
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• pp.45-68
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• 2004

The word of lignin is derived from the Latin word 'ligum' meaning wood. Lignin is complex polymer consisting of coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol unit and has an amorphous, three dimensional network structure which is hard to be hydrolyzed by acid. Lignin is found in the cell wall of plants lignified. The mode of polymerization of these alcohols in the cell wall lead to a heterogeneous branched and cross-linked polymer in which phenyl propane units are linked by carbon-carbon and carbon-oxygen bonds. This polymerization of precursors, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol to lignin is formed by enzymic dehydrolyzation. The reaction is initiated by an electron transfer which results in the formation of resonance-stabilized phenoxy radical. The combination of these radicals produces a variety of dimers, trimers and oligomers and so on. Lignin research has been divided into basic and practical application field. The basic studies contains biosynthesis, chemical structure, distribution in the cell wall and reactivity by reductants, oxidants and organic solvents. The application research will be approached the reaction of lignin in various pulp making involving pulp bleaching and its effect on pulp qualities. Lignin also will be studied for the production of fine chemicals, polymer products and the conservation into an energy source like petroleum oil because the amount of lignin produced in pulp making process is more than 51,000,000 tons per year in the world. Both basic and application research must lay emphasis on the development for the utilization of lignin and the pulping process. But these researches can not be completed without understanding lignin structure containing functional groups. Therefore, this paper was focused on the review of lignin formulation which has been studied since 1948 in chronological order. This review was based on monomers, dimers, trimers and tetramers of phenyl propane unit structures which were isolated and identified by different methods from various wood.ious wood.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.3907-3915
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• 2013

Cudrania tricuspidata has been used for a long time as a traditional herb medicine in Korea nad China. This paper has shown the experimental results about the physiological activities of water-, ethanol-, ethyl acetate-soluble fractions from ethanolic extracts of leaves, stems and roots of Cudrania tricuspidata. The effects of these fractions on the growth of various cells have exhibited that the ethyl acetate fractions from leaves, stems and roots inhibited significantly the growths of macrophage(RAW 264.7 cell), melanoma cell(B16-F10 cell), fibroblast cell(CCD-986sk cell), and lung carcinoma cell(A549 cell). The water and ethanol fractions of leaves and ethanol fraction of stems demonstrated better antioxidant activities scavenging radicals than other fractions when compared with the concentrations of different fractions for scavenging free radical DPPH (di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium).