Coenzyme Qn 유도체들의 합성

최원식,어진용,남석우,김재훈,이영행,Choi, Won-Sik,Eo, Jin-Yong,Nam, Seok-Woo,Kim, Jae-Hoon,Lee, Young-Haeng 대한화학회 2007 대한화학회지 Vol.51 No.6

6${\beta}$-Bromopenicillanate로부터 6-(Carboxymethylthio) penicillanic Acid 유도체의 합성

최원식,이영행,이채호,Won-Sik Choi,Young-Haeng Lee,Chai-Ho Lee 대한화학회 1991 대한화학회지 Vol.35 No.5

6${\beta}$-bromopenicillanic acid(4a)와 p-nitrobenzylbromide, 3-bromophthalide, chloromethylpivalate 및 1-chlorodiethylcarbonate의 반응으로 6${\beta}$-bromopenicillanates(4b~4e)을 합성하였으며, 6${\beta}$-bromopenicillanic acid(4a)와 그의 ester(4b~4e)를 thioglycolic acid와 친핵성 치환반응시켜 새로운 $\beta$-lactam계 화합물인 6-(carboxymethylthio)penicillanic acid(5a)와 그의 ester(5b~5e)를 얻었다. Reaction of 6${\beta}$-bromopenicillanic acid(4a) with p-nitrobenzylbromide, 3-bromophthalide, chloromethylpivalate and 1-chlorodiethylcarbonate afforded 6${\beta}$-bromopenicillanates(4b~4e). New ${\beta}$-lactam compound, 6-(carboxymethylthio)penicillanic acid(5a) and the other esters(5b~5e) were prepared by nucleophilic substitution reaction of 6${\beta}$-bromopenicillanic acid(4a) and the other esters(4b~4e) with thioglycolic acid.

선박엔진의 Supply Unit용 SNCM420H의 절삭특성

최원식,성봉수,강창원,문희준,권주리,Choi, Won-Sik,Sung, Bong-Soo,Kang, Chang-Won,Mun, Hee-Joon,Kwon, Ju-Ri 한국생산제조학회 2010 한국생산제조학회지 Vol.25 No.5

SNCM420 steel is one of the cam shaft materials which are used in the supply unit for ship engine cam shaft. In this study the assessment of cutting behavior was conducted for the SNCM 420 steel and SM45C steel with various cutting conditions as depth of cut 0.5, 1.0, 1.5, 2.0mm and feed rate 0.1~0.3m/rev. The controlled chip was produced in feed rate 0.2, depth of cut 1.0 for SNCM420 and feed rate 0.2, depth of cut 2.0 for SM45C. There is no difference cutting force between SM45C and SNCM420 steels.

한국산 옻나무로부터 추출.분리한 생리활성 물질들의 항산화 효과 및 세포독성

최원식,김동길,이영행,김장억,이성은,Choi, Won-Sik,Kim, Dong-Kil,Lee, Young-Haeng,Kim, Jang-Eok,Lee, Sung-Eun 한국응용생명화학회 2002 한국농화학회지 Vol.45 No.3

한국산 옻나무의 메탄올추출물과 유기용매 분획의 항산화 효과를 조사하였다. 항산화 효과는 수소공여 억제능, 과산화지질 형성 억제능, xanthine oxidase저해 활성과 아질산염 소거능으로 측정한 결과, ethyl acetate 분획이 가장 뛰어난 효과를 나타내었다. 이 분획의 생리활성 물질을 분리하기 위하여, rotatory locular counter current chromatography(RLCCC), Sephadex LH-20 column chromatograpy와 HPLC등의 방법을 사용하여, 1,2,3-trihydroxybenzene, methyl 3,4,5-trihydroxybenzoat와 3,4,5-trihydroxybenzoic acid를 분리하였다. 이중 methyl 3,4,5-trihydroxybenzoate는 butylated hydroxyanisole(BHA)이나 butylated hydroxytoluene(BHT)보다도 강한 항산화 효과를 나타내었다. 그러나 세포독성 실험에서는 이들 물질들이 암세포주에 대하여 활성이 높지 않았다. 이상의 결과로 methyl 3,4,5-trihydroxybenzoate은 뛰어난 항산화 효과를 지닌 식품첨가물로서의 이용 가능성을 제시할 수 있다. Antioxidative activities of solvent fractions obtained from Korean Rhus vernicifera, being used in food industry and as a traditional medicine, were examined by the methods of DPPH scavenging activity, inhibitory effect on autooxidation of linoleic acid, nitrite scavenging activity and the inhibitory effect on xanthine oxidase activity. Ethyl acetate fraction showed potent antioxidative activities. Three compounds were isolated from the ethyl acetate fraction by rotatory locular counter current chromatography (RLCCC), Sephadex LH-20 column chromatography and HPLC. The isolated compounds were 1,2,3-trihydroxybezene, methyl 3,4,5-trihydroxybenzoate and 3,4,5-trihydroxybenzoic acid determined by GC/MS and, $^1H$ and $^{13}C$ NMR. Among the isolated compounds, methyl 3,4,5-trihydroxybenzoate showed the strongest antioxidative activity than artificial antioxidants, BHA and BHT in various methods. However, these isolated compounds did not show cytotoxicity effects on the human cancer cell lines. Therefore, we may suggest that methyl 3,4,5-trihydroxybenzoate can be used as a food additive possessing the potent antioxidative activity.

Tribological Characteristics in $40{\mu}m$ Dimple Pattern for Hexagonal Array

최원식,채영훈,Choi, Won-Sik,Chae, Young-Hoon,Umehara, Noritsugu Korean Tribology Society 2009 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.17 No.5

본 연구에서는 pin-on-disk 마찰 시험기를 통하여 Hexagonal 배열 $40{\mu}m$ Dimple 패턴의 효과를 실험하였다. 마찰 실험은 미끄럼 속도가 $0.06{\sim}0.34m/s$로 하였으며 마찰하중은 $20{\sim}100\;N$의 범위로 하였고, Dimple의 밀도는 $10{\sim}25%$의 범위로 제작하여 실험을 행하였다. 일반적으로 속도가 증가하고 하중이 감소할수록 마찰계수는 감소하는 경향을 나타내었으며, Dimple에 의한 마찰저감 효과는 속도가 $0.14{\sim}0.26m/s$의 범위에서 나타났다. $40{\mu}m$ Hexagonal 배열 Dimple 패턴의 마찰 특성에서는 밀도가 12.5%에서 가장 좋은 경향을 나타내었다.

Friction Characteristics of CNx Coated Dimple Pattern with Hexagonal Array

최원식,Choi, Won-Sik,Umehara, Noritsugu Korean Tribology Society 2011 한국윤활학회지(윤활학회지) Vol.15 No.3

In this study, we examined the friction characteristics of a dimple pattern on a carbon nitride coating. The study was conducted with a hexagonal array 40 ${\mu}m$ dimple pattern on a steel bearing containing a CNx coating. The area density of the dimple patterns were varied between 5% and 25%, the speed was varied from 0.06-0.26 m/s, and the load was varied between 20-100N. In general, we found that as the velocity increased, the friction coefficient increased. Furthermore, the friction coefficient was lowest at a load of 40N. The friction coefficient of the non-coated specimen was 0.025-0.15; on the other hand, the friction coefficient of the coated specimen was 0.002-0.02. Thus, we determined that the coated materials could reduce the friction coefficient by a factor of 7.5.

1910년대 친일문학의 근대성

최원식(Choi Won-Sik),서영채(토론자) 한림대학교 아시아문화연구소 1998 아시아문화 Vol.- No.14

SNS 쉐프 인플루언서 특성이 인게이지먼트, 소비자 태도 및 구매의도에 미치는 영향 : SNS 유형의 조절효과

최원식(Choi, Won-Sik),김영중(Kim, Young-Joong) 한국외식경영학회 2021 외식경영연구 Vol.24 No.2

본 연구에서는 SNS 쉐프 인플루언서 특성이 인게이지먼트, 소비자 태도 및 구매 의도에 미치는 영향 관계를 규명하고자 하였다. 본 연구의 목적을 달성하기 위해 SNS 사이트에서 쉐프 인플루언서들을 보고 제품을 구매한 경험이 있는 수도권에 거주하는 20세 이상의 소비자들을 대상으로 설문조사를 시행하여 총 239부를 실증분석에 사용하였다. 분석 결과, 첫째, 쉐프 인플루언서 특성의 하위요인인 전문성, 매력성, 진정성과 인게이지먼트의 관계에서 모두 유의한 영향을 미치는 것으로 분석되었다. 둘째, 인게이지먼트는 소비자 태도 및 구매 의도에 유의한 영향을 미치는 것으로 나타났다. 셋째, 소비자 태도는 구매 의도에 유의한 영향을 주는 것으로 분석되었다. 마지막으로, SNS 유형은 인플루언서 특성과 인게이지먼트 관계에서 부분적으로 조절 효과가 있는 것으로 확인되었다. This study was to investigate the effect relationship on SNS chef s influencer characteristics to engagement, consumers attitude and purchase intention. To achieve the purpose of this research, a total of 239 copies were used for empirical analysis by conducting a survey of consumers over 20 years of age living in the metropolitan area who have seen chef influencers on SNS sites and have purchased products. The analysis results, First, it was analyzed that the relationship between professionality, attractiveness, authenticity to engagement which are sub-factors of chef’s influencer characteristics when all had a significant effect. Second, it was found that the engagement had a significant effect on consumers attitude and purchase intention. Third, consumers attitude was verified to have a significant effect on purchase intention. Finally, the moderating effect of SNS type was partially confirmed in the relationship between chef’s influencer characteristics and engagement.

3-[(4-카르복시-5-에틸티오이소티아졸-3-일)옥시메틸] 세파로스포린 유도체들의 합성 및 항균력에 관한 연구

최원식(Won Sik Choi),박의석(Eui Suk Park),박규종(Kyu Jong Park),이영행(Young Haeng Lee) 대한약학회 2000 약학회지 Vol.44 No.2

New cephalosporin antibiotics, 3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyll-7-[(1H-tetra-zol-1-yl)acetamido]-3-cephem-4-carboxylic acid 2, 3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyl]-7-[(2-aminothiazol-4-yl)acetamidol-3-cephem-4-carboxylic acid 3, 3-[(4-carboxy-5-ethylthioisothiazol-3-yl)-oxymethyl]-7-[5-(ethylthio-3-hydroxyisothiazol-4-yl)carboxamido]-3-cephem-4-carboxylic acid 4, 3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyl]-7-[(Z)-2-(fur-2-yl)-2-(methoxyimino)acetamido]-3-cephem-4-carboxylic acid 5, 7-[(Z)-2-(2-aminothiazol-4-yl)-2-[(alkoxyimino)acetamido]-3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyl]-3-cephem-4-carboxylic acid 6-8 were synthesized. Antibacterial activities and structure-activity relationships of these new cephalosporin derivatives were examined. Among them, 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-l-methylethoxyimino)acetamido]-3-[(4-carboxy-5-ethylthylthioisothiazol-3-yl)oxymethyl]-3-cephem-4-carboxylic acid 7 exhibited good antibacterial activities compared to cefotaxime and ceftriaxone.

친환경 레스토랑의 서비스스케이프가 소비자의 지각된가치, 태도 및 행동의도에 미치는 영향

최원식(Won Sik Choi),이수범(Soo Bum Lee) 한국조리학회 2012 한국조리학회지 Vol.18 No.5

The purpose of this study is to secure the basic data for the physical environment of an eco-friendly restaurant by surveying and analyzing customer perceptions of the servicescape of an eco-friendly restaurant and to verify the organic causation of the servicescape of an eco-friendly restaurant and customer perceived value, attitude and behavior intention. The samples for empirical analysis were selected from the customers over 20 years who lives in Seoul and Kyung-gi suburbs have experienced visiting eco-friendly restaurant or green restaurant more than once a month. Total 300 copies of questionnaire were distributed for the survey from the second day to the fifteenth day of April for 14 days, and total 264 (88.0%) copies of survey questionnaire except for some questionnaires that had much strong lean tendency or the missing value was discovered. The research results are as follows; when a customer recognizes an eco-friendly restaurant favorably, he or she considers that servicescape plays an important role in deciding perceived value through tangible and intangible perceived values. Since, customer perceived value has a positive effect on attitude and behavior intention, the customer considers as affected on his/her behavior intention when satisfied with the eco-friendly restaurant, which is considered that positive customer attitude will have an effect on behavior intention. Thus, it is considered based on this in-depth analysis result that maintaining and providing servicescape of high standard in the manager`s perspective will have a direct effect on ensuring tangible outcomes.