• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.520-522
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• 2008

A new compound named soraphinol C (1) was isolated from myxobacteria Sorangium cellulosum KM1001 a soil isolate, together with a structurally related known compound, 4-hydroxysattabacin (2). These compounds were isolated by silica gel column chromatography and recycling preparative HPLC, consecutively. The structures of the compounds were determined on the basis of combined spectroscopic analyses. Compounds 1 and 2 exhibited antioxidant activity as a radical scavenger in the experiment using a hydrophilic free-radical initiator, 2,2'-azobis(2-amidinopropane)dihydrochloride with ORAC values of 0.956 and 0.617, respectively.

• 한국식품과학회지
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• 제50권1호
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• pp.21-27
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• 2018

본 연구에서는 식품의 가공이나 조리 시 빈번히 적용되는 가열처리에 의한 심황색소의 화학안정성, 산화방지활성 및 세포독성의 변화를 조사하였다. $95^{\circ}C$에서 각 시간별로 가열처리한 심황색소는 가열시간이 증가할수록 발색도가 감소하였으며, 형광도는 초기 가열 시에 증가하다 감소하는 양상을 보였다. HPLC 분석 결과 3종의 쿠쿠미노이드 중 쿠쿠민이 가열처리에 가장 민감하였으며 BMC가 가장 안정하였다. 가열 처리 후의 심황색소에 의해 ABTS 라디칼, AAPH peroxyl 라디칼 및 아질산염 소거활성이 증가하였으나, DPPH 라디칼 소거활성에는 변화가 없었다. 가열처리 시간의 증가에 따라 심황색소로 부터의 $H_2O_2$ 생성능이 증가한 반면, 정상장관계 세포 INT 407 및 대장암 세포 HCT 116를 대상으로 한 세포독성평가에서는 가열처리 후 심황색소의 활성이 유의적으로 약화되었다. 본 연구결과는 다양한 가공식품에 첨가되는 심황색소의 화학안정성 및 생리활성이 가열처리에 의해 크게 영향을 받으며, 생리활성 증진을 목적으로 첨가되는 심황색소에 이러한 가열처리 효과가 고려되어야 함을 시사한다.

• 한국응용과학기술학회지
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• 제26권1호
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• pp.93-101
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• 2009

Antistatic acrylic resin is made from n-butyl methacrylate, methyl methacrylate, dimethyl amino ethyl methacrylate(DMAEMA), 2-ethyl hexyl methacrylate, hydroxy ethyl methacrylate, 2,2'-azobis iso-butyronitrile by synthesis. To achieve a lowest surface resistance of antistatic acrylic resin was applied to a variety of synthesis processes. The acrylic resin has been determined from the value of surface resistance and -then the antistatic acrylic resin including dimethyl amino ethyl methacrylate of the 10%, 20% and 30% is synthesized. Finally, dimethyl sulfate(DMS) on a variety of weight ratios is added to antistatic acrylic resin. When DMAEMA / DMS weight ratio is 1/1, antistatic acrylic resin isn't haze the lower the surface resistance. Compared to the traditional antistatic agent, all aspects of the physical properties is outstanding.

• Fibers and Polymers
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• 제6권4호
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• pp.277-283
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• 2005

In order to prepare high molecular weight poly(methyl methacrylate) (PMMA)/silver nanocomposite microspheres, methyl methacrylate was suspension-polymerized in the presence of silver nanoparticles at low temperature with 2,2'-azobis(2,4-dimethylvaleronitrile) as an initiator. The rate of conversion was increased by increasing the initiator concentration. When silver nanoparticles were added, the rate of polymerization decreased slightly. High monomer conversion (about $85\%$) was obtained in spite of low polymerization temperature of $30^{\circ}C$. Under controlled conditions, PMMA/silver microspheres with various number-average degrees of polymerization (6,000-37,000) were prepared. Morphology studies revealed that except for normal suspension microspheres with a smooth surface, a golf ball-like appearance of the microspheres was observed, due to the migration and aggregation of the hydrophilic silver nanoparticles at the sublayer beneath the microsphere's surface.

• 혜화의학회지
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• 제7권1호
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• pp.741-748
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• 1998

In order to evaluate the effectiveness of KOK(kyungokko) experimentally used for longevity hematology, erythrocyte hemolysis and TBA(thiobarbituric acid) were measured, after LKOK(low concentration KOK) and HKOK(high concentration KOK) were administrated to mice pretreated with AAPH (2,2'-Azobis(2-amidinopropane), hydrocholoride, free radical inducer. In hematology WBC and hemoglobin were reduced significantly, while the number of platelet was significantly incresed as compared with control. Erythrocyte hemolysis by damage of free radical on cell membrane of RBC and TBA(Thiobarbituric acid) were significantly inhibited in both sample groups as compared with control. These results suggest KOK had antioxidant effect.

• 한국염색가공학회지
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• 제15권3호
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• pp.127-131
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• 2003

Acrylonitrile(AN) was solution-polymerized in dimethyl sulfoxide(DMSO) and tertiary butyl alcohol(TBA) at 30, 40, $50^\circ{C}$ using a low temperature initiator, 2,2'-azobis(2,4-dimethylvaleronitrile) (ADMVN). The low temperature polymerization using ADMVN, DMSO, and TBA is to be successful in obtaining high molecular weight polyacrylonitrile(PAN) with less branches by solution polymerization. Throug a polymerization of AN in DMSO at $30^\circ{C}$, PAN having viscosity-average molecular weight$(M_v)$ of 931,000 was obtained. And then, during AN solution polymerization in DMSO and TBA using a cosolvent system the in-situ formation of microfibrillar structure has been discovered at the cosolvent composition of 24/1$(V_{DMSO}/V_{TBA})$. The simultaneous process of gelation and phase separation of long chain molecules may explain the in-situ formation of PAN fibers during polymerization.

• 생명과학회지
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• 제15권4호
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• pp.626-632
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• 2005

폴리아민은 모든 진핵세포에서 발견되는 다가 양이온성의 저분자 물질이며 세포성장에 필수적인 것으로 알려져 있다. 본 논문에서는 폴리아민의 역할 중에서 산화적인 스트레스에 대한 세포보호 효과를 연구하였다. 쥐의 간세포주인 $Ac_2F$에 산화 스트레스를 유발하기 위하여 2,2'-azobis(2-amidinopropane)dehydrochloride (AAPH)를 처리하였을 때, 세포증식은 농도 의존적으로 감소하였다. 배지에 폴리아민을 첨가하였을 때 세포성장은 농도 의존적으로 증가하였으며 ROS 발생은 현저히 감소하였다. 폴리아민 가운데 특히 spermidine과 spermine이 뚜렷한 세포증식효과를 보였다. Spermine의 경우, $20{\mu}M$농도에서 AAPH에 의해 유도된 ROS발생을 $45\%$나 감소시켰다. 산화 스트레스에 관여하는 효소들 가운데 주된 효소인 superoxide dismutate (SOD)와 catalase (CAT)의 세포 내 단백질을 Western blotting으로 조사한 결과, AAPH는 이 두 가지 단백질의 생성을 억제한 것으로 나타났다. 그러나 spermine을 처리하였을 때 두 단백질의 생산은 모두 정상적으로 회복이 되었다. 또한 세포주기의 중요한 조절 단백질인 cyclin E 역시 AAPH에 의하여 생성이 억제되었다. 이는 AAPH에 의하여 생성된 ROS가 세포주기의 S phase의 진행을 억제한 것으로 생각된다. AAPH에 의한 cyclin E의 억제는 spermine에 의하여 정상적으로 회복되었다. 위와 같은 Spermine의 항산화 효과는 ethidium bromide와 acridine orange를 이용하여 형태학적으로도 증명되었다.

• 한국응용곤충학회지
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• 제61권4호
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• pp.669-673
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• 2022

국내 생산 감로꿀의 기능성 식품 소재로 활용하기 위하여 DPPH (1,1-diphenyl-2-picryl hydrazyl)와 ABTS [2,2-azobis (3-ethylbenzothiazoline-6-sulfonate)] 라디칼 소거능, FRAP (Ferric reducing antioxidant power) 활성, 총 폴리페놀 함량 분석을 통하여 항산화 활성을 평가하였다. 국내 생산 감로꿀은 DPPH와 ABTS 라디칼 소거 활성을 보였으며 최고농도 10 mg/mL에서 DPPH에 비하여 ABTS 라디칼 소거능이 3배 이상 높게 측정되었다. FRAP 분석에서는 ferric ion (Fe³⁺)를 126 µM의 ferrous (Fe²⁺)로 환원시켰다. 또한, 국내 생산 감로꿀에 함유된 폴리페놀성 화합물의 총량은 73.41 mg GAE/kg로 확인되었다. 이상의 연구결과에 비추어 볼 때, 국내 생산 감로꿀의 우수한 라디칼 소거능과 환원력을 가지며 천연 항산화제로 알려진 페놀성 화합물을 존재로 인하여 항산화 활성을 가지는 것으로 확인되었다. 본 연구결과는 국내 생산 감로꿀의 기능성 식품 소재로 활용할 수 있는 기초자료로 제공하는 바이다.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1332-1336
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• 2008

The water extract of Saururus chinensis was investigated for oxygen radical absorbance capacity (ORAC), reducing capacity, metal chelating activity, and intracellular antioxidant activity using HepG2 cell. When 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) was used for the generation of peroxyl radicals in vitro, S. chinensis extract (SC-E) showed the strong and concentration-dependent scavenging activity through donating protons which could be explained by its reducing property. When hydroxyl radicals were generated in vitro through the addition of $Cu^{2+}$ and $H_2O_2$, SC-E demonstrated the antioxidant activity depending on its concentration. In HepG2 cell model, most of intracellular oxidative stress generated by AAPH was efficiently removed by SC-E. However, when $Cu^{2+}$ without $H_2O_2$ was used as an oxidant in the intracellular assay, SC-E partially reduced the oxidative stress caused by $Cu^{2+}$ in cellular antioxidant activity assay system. These results indicate that SC-E could be utilized for the development of functional foods as antioxidant resource in the near future.

• Macromolecular Research
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• 제16권4호
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• pp.329-336
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• 2008

Core/shell ($\pm$)PS/(-)silica nanocomposite particles were synthesized by dispersion polymerization using an amphoteric initiator, 2,2'-azobis [N-(2-carboxyethyl)-2,2-methylpropionamidine] ($HOOC(CH_2)_2HN$(HN=) $C(CH_3)_2CN$=NC $(CH_3)_2C$(=NH)NH $(CH_2)_2COOH$), VA-057. Negatively charged (-6.9 mV) silica was used as the stabilizer. The effects of silica addition time and silica and initiator concentrations were investigated in terms of polymerization kinetics, ultimate particle morphology, and size/size distribution. Uniform hybrid microspheres with a well-defined, core-shell structure were obtained at the following conditions: silica content = 10-15 wt% to styrene, VA-057 content=above 2 wt% to styrene and silica addition time=0 min after initiation. The delay in silica addition time retarded the polymerization kinetics and broadened the particle size distribution. The rate of polymerization was strongly affected by the silica content: it increased up to 15 wt% silica but then decreased with further increase in silica content. However, the particle size was only marginally influenced by the silica content. The zeta potential of the composite particles slightly decreased with increasing silica content. With increasing VA-057 concentration, the PS microspheres were entirely coated with silica sol above 1.0 wt% initiator.