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Regioselective Synthesis of 1,3‐ and 1,2‐Tocopheryl Glyceride Ethers of Carboxylic Acids
Choi, Bo Seul,Choi, Jeongae,Bak, Seonyoung,Koo, Sangho WILEY‐VCH Verlag 2015 European journal of organic chemistry Vol.2015 No.3
<P><B>Abstract</B></P><P>A regioselective synthetic method with which to access 1,3‐tocopheryl glyceride ethers <B>2</B> of diverse carboxylic acids was developed through Bu<SUB>4</SUB>NBr‐catalyzed ring‐opening of tocopheryl glycidyl ether <B>1</B>. Steglich esterification of the 1,3‐tocopheryl acetyl‐glyceride ether <B>2a</B> with various carboxylic acids, followed by selective deprotection of 3‐acetate by LiEt<SUB>3</SUB>BH reduction at –78 °C constitutes a regioselective synthetic method of 1,2‐tocopheryl glyceride ethers <B>4</B>. An example of the differing self‐assembled behavior of phosphorylcholine derivatives <B>6c</B> and <B>7c</B> of 1,3‐ and 1,2‐tocopheryl stearoyl‐glyceride ethers in aqueous solution is also described.</P>
A chain extension method for apocarotenoids; lycopene and lycophyll syntheses
Choi, Jeongae,Oh, Eun-Taek,Koo, Sangho Elsevier 2015 Archives of biochemistry and biophysics Vol.572 No.-
<P><B>Abstract</B></P> <P>The novel C<SUB>5</SUB> benzothiazolyl (BT) sulfone containing an acetal group was prepared as a building block for the chain-extension of apocarotenoids. The double Julia–Kocienski olefination of the BT-sulfone with C<SUB>10</SUB> 2,7-dimethyl-2,4,6-octatrienedial and deprotection of the resulting acetal groups efficiently produced C<SUB>20</SUB> crocetin dial. The higher homologues of C<SUB>30</SUB> and C<SUB>40</SUB> apocarotenoids were prepared from C<SUB>20</SUB> crocetin dial by the repeated application of the Julia–Kocienski olefination of the C<SUB>5</SUB> BT-sulfone and hydrolysis. The scopes of the Julia–Kocienski olefination in the total synthesis of carotenoid natural products were evaluated using the C<SUB>10</SUB> +C<SUB>20</SUB> +C<SUB>10</SUB> coupling protocol. The olefination was sensitive to the steric factor and bulky C<SUB>10</SUB> β-cyclogeranyl BT-sulfone was not able to react with C<SUB>20</SUB> crocetin dial, however, lycopene and lycophyll were efficiently produced by the Julia–Kocienski olefination of C<SUB>10</SUB> geranyl BT-sulfone and hydroxygeranyl BT-sulfone, in which protection of the hydroxyl group was not necessary.</P> <P><B>Highlights</B></P> <P> <UL> <LI> C<SUB>5</SUB> benzothiazolyl sulfone with an acetal group was used for the polyene extension. </LI> <LI> Julia–Kocienski olefination of C<SUB>5</SUB> benzothiazolyl sulfone produced apocarotenoids. </LI> <LI> Lycopene was synthesized from geranyl benzothiazolyl sulfone and crocetindial. </LI> <LI> Hydroxygeranyl benzothiazolyl sulfone produced lycophyll without OH protection. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
학교스포츠클럽 진흥관점에서 바라본 지역사회와의 연계를 위한 협력적 로컬거버넌스 필요성 탐색
유정애(JeongAe You),최윤소(Yoonso Choi) 학습자중심교과교육학회 2019 학습자중심교과교육연구 Vol.19 No.7
본 연구는 보다 내실 있는 학교스포츠클럽 운영을 위하여 지역사회와의 연계를 통한 협력적 거버넌스의 필요성을 탐색하는데 목적이 있다. 이러한 연구의 목적을 달성하기 위하여 국내 학교스포츠클럽 활동과 운영에 관한 선행연구 분석을 통하여 학교스포츠클럽 운영 방해요소를 지도자, 시설, 프로그램 측면에서 도출하고 이를 해결하기 위한 방안으로 협력적 거버넌스 구축의 필요성을 논의하였다. 지도자 측면 에서는 담당교사의 과중한 업무 부담과 교수전문성 부족의 문제를 협력적 로컬거버 넌스 구축을 통해 지역사회 전문 인력을 적극 활용함으로써 해소할 수 있다. 시설 측면에서는 학교스포츠클럽과 지역사회와의 협력적 거버넌스 구축을 통해 지역공공시설 및 스포츠클럽 시설을 공유함으로써 부족한 공간 문제를 해소 할 수 있다. 프로그램 측면에서도 지역사회와 협력적 거버넌스 구축을 통해 학교스포츠클럽이 추구하는 체육의 교육적 가치가 내재된 다양한 신체활동 콘텐츠가 지속적으로 개발 및 확산 될 수 있다. 이러한 연구결과를 토대로 본 연구는 향후 지역사회 연계체계 구축의 실효성 제고를 위해 요구되어지는 학술적, 정책적 제언으로 마무리 하였다. This study aims to explore the justification on developing collaborative local governance to fruitfully manage school sport club. To achieve the purpose, this study firstly drew major hindrances in managing school sport club based on three dimensions -human resource, facilities, and programs- by closely analyzing precedent studies, which are focused on current status of school sport club and then discussed the justification on why school sport clubs need to connect with local communities to ensure internal stability of school sport club based on three infrastructures of school sport club; 1) reducing teachers’ work load and improving professionality; 2) establishing alternatives for facilities; 3) developing and spreading various physical activity programs, which should include the PE values. Lastly, this study concluded with suggestions for practical effectiveness of local connections that are required to promote the school sport club system.
Kim, Jeonga,Kim, Kyeong Rak,Hong, Yeongran,Choi, Sunyoung,Yavuz, Cafer T.,Kim, Jin Woong,Nam, Yoon Sung American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.24
<P>Metal recovery from electronic waste and industrial wastewater has attracted increasing attention to recycle precious metals and inhibit the emission of hazardous heavy metals. However, the selective recovery of precious metals with a large quantity is still very challenging because wastewater contains a variety of different cations while precious metal ions are relatively scarce. Here, we introduce a simple method to selectively increase the adsorption of gold ions using tannin-coated porous polymer microspheres through photochemical reduction. Mesoporous poly(ethylene glycol dimethacrylate-<I>co</I>-acrylonitrile) microspheres with an average pore diameter of 13.8 nm were synthesized and used as an adsorbent matrix. Tannic acid (TA) was deposited onto the internal pores of the polymer matrix by simple immersion in an aqueous milieu. TA coatings increased the maximum number of adsorbed gold ions by 1.3 times because of the well-known metal ion chelation of TA. Under light illumination, the maximum number of adsorbed gold ions dramatically increased by 6.1 times. We examined two distinct mechanisms presumably involved in the enhanced adsorption: the photooxidation of TA and plasmon-induced hot electrons. Moreover, TA-coated microspheres exhibited remarkable selectivity for gold ions among competing metal ions commonly found in waste resources. This work suggests that the photochemically activated TA can serve as an excellent adsorbent for the selective and efficient recovery of gold ions from wastewater.</P> [FIG OMISSION]</BR>
Kima, Jinil,Jeonga, Ja In,Kim, Kwang Min,Choi, Inho,Pratleyd, Richard E.,Lee, Yong-Ho 한국통합생물학회 2014 Animal cells and systems Vol.18 No.3
This study examined the effects of long-term consumption of a high-fat diet (HFD) on glucose metabolism in C57BL/6 mice. A total of 95 male 6-week-old mice were divided into normal diet (ND) and HFD groups until 16, 26, 36, 47, or 77 weeks of age. Plasma and blood glucose and insulin levels and area under the glucose curve ($AUC_{glucose}$) during an intraperitoneal glucose tolerance test were measured. Quantitative real-time PCR was performed to determine the mRNA expression levels of glucose transporter 4 (GLUT4) in adipose tissue. $AUC_{glucose}$ levels in HFD mice at 16, 26, and 36 weeks were significantly higher than those in ND mice (p < 0.001) and significantly reduced in HFD mice at 47 and 77 weeks. Nonfasting plasma glucose concentrations in both groups were significantly decreased at 47 and 77 weeks ($p{\leq}0.05$). Insulin levels in HFD mice at 47 and 77 weeks were 12.5% lower than those at 36 weeks. Relative GLUT4 mRNA expression in adipose tissue of HFD mice was significantly decreased at 26 and 36 weeks and increased at 47 and 77 weeks. These data suggest that the glucose tolerance was impaired by relatively short-term high-fat feeding and significantly improved by very long periods of high-fat feeding with restored GLUT4 expression in adipose tissue in HFD mice. The differential effects of short-and long-term HFD on glucose metabolism must be considered for recharacterizing the diet-induced obesity and clarify the pathogenesis of metabolic disorders in this animal model.