• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.103.1-103.1
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• 2014

Due to their excellent optical and electrochemical properties, conjugated polymers have attracted much attention over the last two decades and employed to opto-electrical devices. In particular, conjugated polymers possess many attractive features that make them suitable for a variety of sensing task. For example, their delocalized electronic structures can be strongly modified by varying the surrounding environment, which significantly affected molecular energy level. In other word, conjugated polymers can detect and transduce the environmental information into a fluorescence signal. Conjugated polymers also display amplified quenching compared to small molecule counterparts. This amplified fluorescence quenching is attributed to the delocalization and migration of the excitons along the conjugated polymer backbones. Long backbones of conjugated polymer provide the transporting path for electron as a conduit, allowing that excitons migrate rapidly into quencher site along the backbone. This is often referred to as the molecular wire effect or antenna effect. Moreover, structures of conjugated polymers can be easily tailored to adjust solubility, absorption/emission properties, and regulation of electron/energy transfer. Based on this versatility, conjugated polymers have been utilized to many novel sensory platforms as a promising material. In this tutorial, I will highlight a variety of fluorescence sensors base on conjugated polymer and explain their sensory mechanism together with selected examples from reference literatures.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1734-1742
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• 2011

Conjugated linolenic acid (CLnA) and conjugated linoleic acid (CLA) are positional geometric isomers with three and two double bonds, respectively. In this study, perilla seed oil containing 60% ${\alpha}$-linolenic acid (C18:3) and 30% linoleic acid (C18:2) was used as a reaction substrate. After the perilla seed oil was hydrolyzed, conjugated fatty acids were synthesized using different reaction parameters, such as reaction time and concentration of sodium hydroxide. As a result, CLnA, CLA, and other newly synthesized conjugated isomers were present at levels of 14.5%, 14%, and 42.2%, respectively, when the reaction was performed with 20% NaOH, at $180^{\circ}C$, and for 1 hr. The results of GC-MS and fourier transform infrared spectroscopy (FT-IR) showed that CLnA isomer of cis-9, trans-11, and trans-13 octadecatrienoate, CLA isomer of cis-9, trans-11, and trans-10, cis-12 octadecadienoate, and other conjugated isomers were produced. Using urea, ${\alpha}$-linolenic acid could be concentrated from perilla seed oil hydrolysate. After concentration by urea, the concentration of ${\alpha}$-linolenic acid reached about 70%. After alkaline-isomerization was performed on the urea fraction containing 70% ${\alpha}$-linolenic acid, the content of CLnA increased up to 16.6%.

• YAKHAK HOEJI
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• v.46 no.3
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• pp.197-202
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• 2002

Lectin-conjugated praecoxin A, which has developed as a missile antitumor drug, is the one that has conjugated with wheat germ agglutinin (WGA), a kind of carbohydrate-binding protein (lectin) especially bound to melanoma. Praecoxin A is a kind of tannin extracted and purified from plants. Beside this direct antitumor effect as tannins, we have examined an activation of macrophage by lectin-conjugated praecoxin A. We also confirmed the gene expression of IL-1 $\beta$, both in vitro and in vivo. We added 1, 10, 100 $\mu\textrm{g}$/mι of lectin-conjugated praecoxin A, 10 $\mu\textrm{g}$/mι of lectin, 10 $\mu\textrm{g}$/mι of praecoxin A to normal murine macrophage and analyzed the extracted total RNAs by RT-PCR after 4, 8, 12, 24 hours. Our data demonstrated that lectin-conjugated praecoxin A increased IL-1$\beta$, mRNA expression in a dose dependent manner. However, the effectiveness of lectin-conjugated praecoxin A was not superior to lectin and praecoxin A.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.586-593
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• 2009

Since conjugated linoleic acid (CLA) was identified as a principal anticancer component from ground beef in the 1980s, CLA research has discovered that CLA has a wide range of biologically beneficial effects. Clinical studies with CLA are on the rise, and it is apparent that CLA may not be as effective in humans as in rodents, in particular its anti-obesity aspect. In addition, research with regard to other conjugated fatty acids as well as CLA metabolites is still in its infancy. Investigation of bioactivities for other conjugated fatty acids and CLA metabolites may help to extend the understanding of CLA and its mechanisms of actions. This may pose an opportunity to use CLA more efficiently and expand the future use of other conjugated fatty acids as pharmacological agents to assist current treatments.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.601-606
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• 2000

Recently, studies on missile antitumor drugs, which selectively act on tumor cell and display drug effects, have been performed. These missile antitumor drugs which can increase drug effects and decrease side effects, are ideal medication method. Lectin has been reported as tumor cell specific binding protein and tannin as antitumor substance. In this study, we studied inhibition of melanoma metastasis by lectin-conjugated ellagitannin and used praecoxin A as ellagitannin source. Mouse melanoma cell, B16-F10, was injected into the sole of forefoot of C57BL/6 mouse, and after administration with drug, the number of pulmonary tumor colony was counted. The administration of praecoxin A, lectin-praecoxin A mixiture, and lectin-conjugated praecoxin A was started after amputation of established tumor foci at right forefoot of mice and continued for 3 weeks with i.p. injection of one of those drugs A every 24 hours. Lectin-praecoxin A mixture, and lectin-conjugated praecoxin A significantly reduced the number of spontaneous pulmonary metastasis. Exposure to 5 mg/kg of lectin-praecoxin A mixiture and lectin-conjugated praecoxin A produced a statistically significant 38.3%, 41.8% reduction in the number of remaining pulmonary metastasis. These results suggest that metastasis inhibition by lectin-praecoxin A mixiture and lectin-conjugated praecoxin A are better than that of praecoxin A.

• Korean Journal of Microbiology
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• v.43 no.2
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• pp.111-115
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• 2007

The aim of this study was to isolate and identify men fungus which produces conjugated linoleic acid. IS-13 fungus hydrogenated conjugated linoleic acid and trans-11 vaccenic acid within 12 hr after addition of linoleic acid. The homology of IS-13 rumen fungus was compared with internal transcribed spacer 1 region (ITS1)sequences of twenty three men fungi. The length of ITS1 region of IS-13 isolate was 218 bp. IS-13 isolate has the most similar sequence (98% matched) with Orpinomyces species according to maximum-likehood and distance matrix results. The result supported that IS-13 isolate belonged to Orpinomyces genus.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.130-134
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• 2008

Carbohydrate-conjugated chlorins were synthesized for use as biosensors for the detection of the galectin-3 cancer marker. We used ELISA, SDS-gel electrophoresis, and Bradford assays to examine the binding of galectins to d-(+)-galactose- and b-lactose-conjugated chlorins. The binding affinities of these conjugated chlorins for galectin-3 were quantified using fluorescence spectroscopy. The fluorescence emission of the carbohydrate-conjugated chlorins decreased as the amount of galectin-3 in the binding reaction increased over a limited concentration range, indicating that carbohydrate-conjugated chlorins are potentially useful fluorescence biosensors for the galectin-3 cancer marker.

• Journal of the Korean Applied Science and Technology
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• v.12 no.1
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• pp.119-124
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• 1995

Conventional alkaline catalytic procedure, including sodium methoxide-methanol N, N, N', N'-tetramethyl guanidine-methanol, and acid-catalytic methods of $BF_{3}-methanol$ and HCI-methanol, have been applied for preparing methyl esters from the triacylglycerols of Trichosanthes kirilowiil seeds containing conjugated trienoic acids. The alkaline catalytic methods produce the methyl esters quantitatively without isomerization of the conjugated trienoic acids, but the acid-catalytic ones destroy almost the molecules of conjugated trienoic acids during transesterification of the triacylglycerols although the molar ratios of monoenoic and dienoic acids (non-conjugated) to saturated acids are in good agreement with those obtained from the alkaline methods.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.607-612
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• 2000

Generally, antitumor drugs have strong toxicity and result in damage in normal cells. Previously, lectin has been reported as a tumor cell specific binding protein and tannin as an antitumor substance. In this study, we investigated antitumor activity of lectin-conjugated ellagitannin and used praecoxin A as an ellagitannin source. We injected mouse melanoma cell, B16-F10, on right the femoral region of C57BL/6 mouse. After 10 hours later, first treatment with praecoxin A, lectin-praecoxin A mixiture and lectin-conjugated praecoxin A was carried and followed by injection i.m. every 48 hours. Praecoxin A extended the life of mice up to 14.8% in comparison with the negative control group at 5 mg/kg dose. The life extending ratio of Lectin-praecoxin A mixture was 26.1% at 5 mg/kg dose, and the life extending ratio of lectin-conjugated praecoxin A was 28.7% at 5 mg/kg dose. On the basis of these findings, we suggest that antitumor activities of lectin-praecoxin A mixiture and lectin-conjugated praecoxin A on survival are better than that of praecoxin A.

• Journal of Photoscience
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• v.9 no.3
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• pp.71-74
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• 2002

The fluorescent conjugated aromatic imine derivatives are systematically designed and synthesized as the high yield through the simple one-pot condensation reaction. The emission of the synthesized conjugated aromatic imine derivatives can be tuned efficiently in the range of about 100 nm by the change of electron donating groups constituting parent molecule, which shows the considerable quantum yields from 0.38 to 0.56.