Lipid Peroxidation and Its Toxicological Implications

남태규 한국독성학회 2011 Toxicological Research Vol.27 No.1

Lipid peroxidation is a free radical oxidation of polyunsaturated fatty acids such as linoleic acid or arachidonic acid. This process has been related with various pathologies and disease status mainly because of the oxidation products formed during the process. The oxidation products include reactive aldehydes such as malondialdehyde and 4-hydroxynonenal. These reactive aldehydes can form adducts with DNAs and proteins, leading to the alterations in their functions to cause various diseases. This review will provide a short summary on the implication of lipid peroxidation on cancer, atherosclerosis, and neurodegeneration as well as chemical and biochemical mechanisms by which these adducts affect the pathological conditions. In addition, select examples will be presented where antioxidants were used to counteract oxidative damage caused by lipid peroxidation. At the end, isoprostanes are discussed as a gold standard for the assessment of oxidative damages.

복분자 잼 제조시 페놀 화합물의 함량변화 및 항산화 특성

남태규,이동진,임성은,이상길,김대옥 慶熙大學校 食糧資源開發硏究所 2007 硏究論文集 Vol.26 No.2

Fresh Rubus coreanus Miq. and its jam were extracted using 80% aqueous methanol assisted with homogenization and ultrasonic sound. The extracts wεre analyzed for total phenolics, antioxidant capacity, total anthocyanins, and total flavonoids. One hundred g of fresh fruit had total phenolics and total flavonoids of 1,360.0mg gallic acid equivalents (GAE) and 293.5 mg catechin equivalents (CE), respectively. Antioxidant capacity of fruit assayed by using ABTS and DPPH radicals showed 1,832.4 and 1,095.9 mg vitamin C equivalents (VCE)/100g fresh fruit, respectively. Total anthocyanins of 100g of fruit showed 473.2mg cyanidin 3-glucoside equivalents (CGE). On the basis of fresh fruit (100g), it’is jam had total phenolics of 1,305.1mg GAE, total flavonoids of 268.5mg CE, and total anthocyanins of 326.1mg CGE. Antioxidant capacity of jam from 100g of fruit contained 1,706.1 and 1,069.6 mg VCE assayed by using ABTS and DPPH radicals, respectively. The therrnal processing during jam making generally decreased the contents of total phenolics, antioxidant capacity, total anthocyanins, and total flavonoids, where more than 90% of total phenolics, antioxidant capacity, and total flavonoids were retained, but over 3l% of total anthocyanins disappeared after jam processing.

능동부하 스위치 구동 회로를 이용한 12비트 80MHz CMOS D/A 변환기 설계

남태규,서성욱,신선화,주찬양,김수재,이상민,윤광섭,Nam, Tae-Kyu,Seo, Sung-Uk,Shin, Sun-Hwa,Joo, Chan-Yang,Kim, Soo-Jae,Lee, Sang-Min,Yoon, Kwang-S. 대한전자공학회 2007 電子工學會論文誌-SD (Semiconductor and devices) Vol.44 No.8

본 논문에서는 무선통신용 송신기에 적용 가능한 12비트 80MHz 전류구동 방식의 D/A 변환기를 설계하였다. 제안된 회로는 3비트 온도계 디코더 회로 4개를 병렬 연결한 혼합형 구조를 채택하였다. 제안된 D/A 변환기는 0.35um CMOS n-well 디지털 표준 공정을 사용하여 구현하였으며, 측정된 INL/DNL은 ${\pm}1.36SB/{\pm}0.62LSB$ 이하이며, 글리치 에너지는 $46pV{\cdot}s$이다. 샘플링 주파수 80MHz, 입력 주파수 19MHz에서 SNR과 SFDR은 58.5dB, 64.97dB로 측정되었다. 전력소모는 99mW로 나타났다. 본 논문에서 구현한 12비트 80MHz 전류구동 혼합구조 D/A 변환기는 고속, 고해상도의 성능을 필요로 하는 다양한 회로에 응용과 적용이 가능하다. This paper describes a 12 bit 80MHz CMOS D/A converter for wireless transceiver. Proposed circuit in the paper employes segmented structure which consists of four stage 3bit thermometer decoders. Proposed D/A converter is manufactured 0.35um CMOS n-well digital standard process and measurement results show a ${\pm}1.36SB/{\pm}0.62LSB$ of INL/DNL and $46pV{\cdot}s$ of glitch energy. SNR and SFDR are measured to be 58.5dB and 64.97dB @ Fs=80MHz and Fin=19MHz with a total power consumption of 99mW. Such results proved that our work has low power consumption, high linearity, low glitch and improved dynamic performance. Therefore, our work can be appled to various high speed and high performance circuits.

Effects of light sources on major flavonoids and antioxidant activity in common buckwheat sprouts

남태규,김대옥,엄석현 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.1

It is known that flavonoids in sprouts were accumulated more under light irradiation than under dark. Light source affecting flavonoid accumulation in sprouts is still investigating. We evaluated the effects of light sources, including red, blue and fluorescent lights, on the flavonoid accumulation and antioxidant activity in common buckwheat sprouts. Experimental results showed that blue light significantly enhanced the contents of C-glycosylflavones, including orientin, vitexin and their isomers, and rutin and a rutin isomer. Sprouts grown under blue light exhibit also the highest total phenolics and total flavonoids as well as the highest antioxidant activities. It was found that isoorientin is the highest antioxidant flavonoid whereas numerous former studies suggested that rutin is a typical antioxidant compound in common buckwheat. These results indicated that blue light could be applied for enhancing not only the content of flavonoids but also antioxidant activity in common buckwheat sprouts.

색차에 미치는 염색공정개선과 색차감소기술개발

남태규,이주형,이난형,김삼수,노석균 영남대학교 지역발전연구소 1996 새마을지역개발연구 Vol.18 No.-

In order to analysis of colour difference in dyeing process of the production field, several dyestuffs were selected for examine pH independance, step dyeing and migration test. And another investigation also carried out how much causes colour difference to insufficient washing process a t pre-treatment process. The results were as follows. 1. All used dyestuffes behavior showed high dye-up take a t the low pH condition. 2. In the examination of pH independence, C. I. Acid Red 57 and C. I. Acid Yellow 199 dyestuffs were exception behavior to used all dyestuffs. 3. By step dyeing results, mixed system of C. I. Acid blue 62 and C. I. Acid Red 57 have a good color reproducibility.

Estimated daily per capita intakes of phenolics and antioxidants from coffee in the Korean diet

이봉한,남태규,김선영,천옥경,김대옥 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.1

This study evaluated the daily per drinkerintakes of total phenolics, total flavonoids, and antioxidantsfrom coffee in the Korean diet. Four types of coffee (instantcoffee, decaffeinated instant coffee, roasted coffee,and coffee mix) were selected and analyzed. Based on theKorea National Health and Nutrition Examination Surveyin 2012, the daily intakes per coffee drinker were estimatedto be 348.6 mg gallic acid equivalents for phenolics,222.5 mg catechin equivalents for flavonoids, and370.8 mg vitamin C equivalents (DPPH assay) or546.7 mg vitamin C equivalents (ABTS assay) forantioxidants. Men had higher intakes of instant coffee andcoffee mix, while women had a higher intake of roastedcoffee. Regarding age categories, over 58% of the coffeeconsumers were 30–59 years old. This study revealed that,in Korea, approximately half of the people drank about 1.4cups of roasted coffee or 2.0 cups of instant coffee everyday.

Antioxidative and Neuroprotective Effects of Volatile Components in Essential Oils from Chrysanthemum indicum Linné Flowers

이봉한,남태규,박우정,강희,허호진,정대균,김건희,김대옥 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.2

Chrysanthemum indicum Linné, belonging to the family Compositae, is a perennial herb that is widespread in Korea. C. indicum Linné flowers have been traditionally used as an oriental medicine for treatment of infectious diseases. The chemical compositions, antioxidant capacity, and neuroprotective effects of volatile components in essential oils from C. indicum Linné flowers were investigated. GCMS analysis of essential oils revealed the 15 major components of 1,8-cineole, o-cymene, camphor, pinocarvone, chrysanthenyl acetate, bornyl acetate, trans-caryophyllene, terpinen-4-ol, umbellulone, trans-pinocarveol, cis-verbenol, borneol, α-terpineol, caryophyllene oxide, and thymol. Thymol had the highest antioxidant capacity. Essential oils and thymol dose-dependently decreased intracellular oxidative stress, exhibited anticholinesterase activities, and increased the cell viability of neuronal PC-12 cells. Essential oils and thymol from C. indicum Linné flowers can be sources of natural antioxidants and functional foods.

곶감의 페놀 화합물 및 항산화 특성

이동진,남태규,김은옥,김대옥 慶熙大學校 食糧資源開發硏究所 2008 硏究論文集 Vol.27 No.-

곶감의 메탄올 농도별 추출에 따른 페놀화합물의 함량변화 및 항산화 특성을 알아보고자 메탄올을 추출용매로 하여 각기 다른 농도 조건에서 추출한 곶감에 존재하는 총페놀화합물, 총플라보노이드 함량, ABTS와 DPPH radical을 이용한 항산화 활성을 측정하였다. 그 결과 80% 메탄올 추출에서 총페놀은 950.63mg GAE/100g, 총플라보노이드는 263.93 mg CE/100g, ABTS는 2,198.56mg VCE/100g, DPPH는 1,355.74mg VCE/100g 함량을 보였으며, 60%와 absolute 메탄올 추출과 비교하여 가장 효과적인 추출용매였다.

Additive Antioxidant Capacity of Vitamin C and Tocopherols in Combination

임성빈,남태규,이상길,김영준,Ock Kyoung Chun,김대옥 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.3

Vitamin C (ascorbic acid) and vitamin E(tocopherols) are water-soluble and fat-soluble essentialnutrients, respectively, present ubiquitously in cellularmembranes and plasma through dietary intake of fruits andvegetables. These vitamins act as antioxidants by virtue oftheir free hydroxyl groups. To quantitatively assess thevitamin C-tocopherol interaction in generating totalantioxidant capacity, various binary mixtures of vitamin Cand tocopherols (α, β, δ, and γ) were titrated with ABTSradicals. In this assay, the antioxidant capacity of tocopherolsincreased as follows: β-tocopherol<α-tocopherol<δ-tocopherol<γ-tocopherol. As the total concentration ofmixed antioxidants vitamin C and tocopherols increased,the total antioxidant capacity increased linearly. The sumof the individual antioxidant capacities of vitamin C andtocopherol in the assay was very close to the totalantioxidant capacity of the corresponding combination oftwo compounds. Using this assay system, and in theconcentration ranges applied, vitamin C and tocopherols incombination displayed additive interaction.

무선랜용 I/Q 채널 12bit 120MHz CMOS D/A 변환기 설계

하성민,윤광섭,남태규,서성욱,신선화,주찬양 대한전자공학회 2006 電子工學會論文誌-SD (Semiconductor and devices) Vol.43 No.11

This paper describes the design of I/Q channel 12bit Digital-to-Analog Converter(DAC) which shows the conversion rate of 120MHz and the power supply of 3.3V with 0.35um CMOS n-well 1-poly 4-metal process for advanced wireless transceiver. The proposed DAC utilizes 4-bit thermometer decoder with 3 stages for minimum glitch energy and linearity error. Also, using a optimized 4bit thermometer decoder for the decrement of the chip area. Integral nonlinearity(INL) of ±1.6LSB and differential nonlinearity(DNL) of ±1.3LSB have been measured. In single tone test, the ENOB of the proposed 12bit DAC is 10.5bit and SFDR of 73dB(@ Fs=120MHz, Fin=1MHz) is measured, respectively. Dual-tone test SFDR is 61 dB (@ Fs=100MHz, Fin=1.5MHz, 2MHz). Glitch energy of 31 pV·s is measured. The converter consumes a total of 105mW from 3.3-V power supply. 본 논문에서는 무선통신용 송수신기에 집적화할 수 있도록 0.35μm CMOS n-well 1-poly 4-metal 공정을 이용하여 3.3V의 전원 전압으로 동작하는 I/Q 채널 12비트 120MHz 전류구동 D/A 변환기를 설계하였다. 설계된 12비트 D/A 변환기는 4비트 온도계 디코더를 3단 구성하여 글리치 에너지와 선형오차 특성을 최소화 하였다. 측정된 선형오차인 INL/DNL은 각각 ±1.5 LSB, ±1.3LSB이며, 글리치 에너지는 31pV·s 로 측정되었고, 전력소모는 105mW이다. 샘플링 및 입력주파수가 각각 120MHz, 1MHz일 때, 싱글 톤 테스트에서 유효비트수는 10.5비트로 측정되었다. 듀얼 톤 테스트에서 1MHz/1.1MHz 의 기저대역신호는 0.9MHz/1.2MHz의 영상신호 차이가 -63dB 나타나는 것으로 측정되었다.