Improving the subcritical water extraction of flavonoids narirutin and hesperidin from Citrus unshiu peel by pulsed electric fields

Hui-Ju Kim,Mi-Ri Kwon,Hye-Ji Kang,Na-Yeon Kim,Hee-Jeong Hwang,Min-Jung Ko,Myong-Soo Chung 한국산업식품공학회 2017 학술대회 및 심포지엄 Vol.2017 No.11

Citrus fruit is important source of flavonoids, mainly flavanones which are narirutin and hesperidin. Those citrus flavonoids have been found to have health-related properties including antioxidant, anticancer, and anti-inflammatory. The main purpose of this study was to verify that the extraction of narirutin and hesperidin from Citrus peel can be more effective by combining pulsed electric field (PEF) pre-treatment and subcritical water extraction (SWE). Citrus unshiu peels were treated with PEF under conditions of electric field strength (3 kV/cm) and times (1 and 2 min). Subsequent SWE was conducted by using a Dionex Accelerated Solvent Extractor (ASE, Model 350) at extraction temperature 170°C for 10 min. The total flavonoids content was measured by using the aluminum chloride colorimetric method and the antioxidant capacity was analyzed by the Ferric reducing antioxidant power (FRAP) assay using spectrophotometer. The concentrations of narirutin and hesperidin were increased as PEF pre-treatment time increased. The highest concentrations of narirutin and hesperidin were 13.41 mg narirutin/g dry citrus peel and 141.16 mg hesperidin/g dry citrus peel at PEF pre-treatment condition of 3 kV/cm and 2 min. The total flavonoids contents of the extracts increased 105.2% and 123.1% for citrus peel PEF treated at 1 and 2 min, respectively. In addition, compared to the untreated sample, PEF pre-treatments of 1 and 2 min increased the antioxidant capacity of the extracts 109.2% and 160.8%, respectively. Therefore, the results demonstrate the potential of PEF pre-treatment to improve the SWE of flavonoids from citrus unshiu peel.

Production of a Recombinant Laccase from Pichia pastoris and Biodegradation of Chlorpyrifos in a Laccase/Vanillin System

( Hui fang Xie ),( Qi Li ),( Min Min Wang ),( Lin Guo Zhao ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.6

The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was 60℃, but it was not stable at high temperature. The enzyme could remain stable at 30℃ for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system (kobs = 0.151) than that in the buffer solution (kobs = 0.028).

Acaricidal target and mite indicator as color alteration using 3,7-dimethyl-2,6-octadienal and its derivatives derived from Melissa officinalis leaves

Min?Seung Kang,Hui-Ju Kim,Jun-Hwan Park,Hoi-Seon Lee 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.4

Ether-free polymeric anion exchange materials with extremely low vanadium ion permeability and outstanding cell performance for vanadium redox flow battery (VRFB) application

Cha, Min Suc,Jo, Sang Woo,Han, Seung Hui,Hong, Soo Hyun,So, Soonyong,Kim, Tae-Ho,Oh, Seong-Geun,Hong, Young Taik,Lee, Jang Yong Elsevier 2019 Journal of Power Sources Vol.413 No.-

<P><B>Abstract</B></P> <P>Ether-free poly(<I>p</I>-phenylene)-based anion exchange membrane materials with outstanding vanadium ion blocking properties are reported. The synthesized ionomers with a rigid backbone structure show small dimensional variations despite the high ion exchange capacities. Among the synthesized membranes, the QPPP-2 membrane with ion exchange capacity of 2.1 meq·g<SUP>−1</SUP> exhibits high anion (OH<SUP>−</SUP>, SO<SUB>4</SUB> <SUP>2−</SUP>, and Cl<SUP>−</SUP>) conductivity. The QPPP-2 membrane shows an extremely low diffusion coefficient (2.12 × 10<SUP>−9</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>) for VO<SUP>2+</SUP>, which is much lower than that of Nafion 115 (2.88 × 10<SUP>−6</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>), indicating the vanadium ion blocking property of QPPP-2. Moreover, the chemical and operational stabilities of the membranes are investigated <I>via</I> ex situ soaking tests in 0.1 M VO<SUB>2</SUB> <SUP>+</SUP> solution and in situ operation tests for 100 cycles, respectively. The vanadium redox flow battery single cell assembled with the QPPP-2 membrane exhibits a coulombic efficiency of 99%, voltage efficiency of 87%, and energy efficiency of 86% during 100 cycles at 80 mA cm<SUP>−2</SUP>. The excellent chemical, morphological, and electrochemical properties of the QPPP-2 membrane make it suitable for use in vanadium redox flow battery.</P> <P><B>Highlights</B></P> <P> <UL> <LI> AEMs are fabricated by a Ni(0)-catalyzed cross-coupling reaction. </LI> <LI> The synthesized ionomers indicated excellent dimensional and chemical stability. </LI> <LI> Ether-free polymeric AEMs showed extremely low vanadium ion cross over. </LI> <LI> The performance of developed AEM showed high EE (87%) with high capacity retention. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Dose-linear pharmacokinetics of oleanolic acid after intravenous and oral administration in rats

Jeong, Dong Won,Kim, Young Hoon,Kim, Hui Hyun,Ji, Hye Young,Yoo, Sun Dong,Choi, Won Rack,Lee, Soo Min,Han, Chang-Kyun,Lee, Hye Suk WILEY PUBLISHERS 2007 BIOPHARMACEUTICS AND DRUG DISPOSITION Vol.28 No.2

<P>The pharmacokinetics of oleanolic acid was evaluated in vitro and in vivo. From Caco-2 cell permeation studies, oleanolic acid was a low permeability compound with no directional effects, suggesting a low in vivo absorption mediated by a passive diffusion. Oleanolic acid was metabolically unstable following incubation with rat liver microsomes in the presence of NADPH. After intravenous injection at doses of 0.5, 1 and 2 mg/kg doses, oleanolic acid showed dose-linear pharmacokinetics as evidenced by unaltered CL (28.6–33.0 ml/min/kg), V<SUB>ss</SUB> (437–583 ml/kg), dose-normalized AUC (16.0–17.9 µg min/ml based on 1 mg/kg) and t<SUB>1/2</SUB> (41.9–52.7 min). Following oral administration of oleanolic acid at doses of 10, 25 and 50 mg/kg, T<SUB>max</SUB>, t<SUB>1/2</SUB>, dose-normalized C<SUB>max</SUB> (66–74 ng/ml based on 25 mg/kg) and dose-normalized AUC (5.4–5.9 µg min/ml based on 25 mg/kg) were comparable between 25 and 50 mg/kg dose, but the plasma concentrations at 10 mg/kg dose were not measurable as they were below the limit of quantitation (2 ng/ml). The absolute oral bioavailability was 0.7% for oral doses of 25 and 50 mg/kg. The extent of urinary excretion was minimal for both i.v. and oral doses. The very low oral bioavailability of oleanolic acid could be due to a poor absorption and extensive metabolic clearance. Copyright © 2007 John Wiley & Sons, Ltd.</P>

우리나라 사이버 무역 현황과 발전방안에 관한 考察

박희종,김민수 明知大學校 經濟硏究所 2002 경영연구 Vol.21 No.1

본 연구에서는 전자상거래, 전자무역, 인터넷 무역 등 새로운 무역방식을 언급하는 여러 용어의 의미와 기존 무역거래와의 차이점을 살펴보면서 사이버 무역의 이점을 본다. 사이버 무역의 진행과정상의 변화는 기존의 무역방법과 크게 다르지 않지만 방법과 수단에서는 매우 큰 차이점이 있다. 국내 사이버 무역을 수행하기 위한 IT산업의 기본적인 인프라의 수준은 괜찮은 것으로 조사가 되었지만 아직까지 종합 무역으로 발전하는 데는 적지 않은 문제점들이 있다. 우리나라의 경우 사이버 무역이 활성화되기 위해서는 크게 3가지의 문제점을 보완해야 할 것으로 본다. 즉 법적·제도적 미비점과 전문인력의 부족 등의 인프라 측면, 인증·보완·지불 등 기술적인 측면, 관세를 포함하는 과세적 측면이 그것이다. 이 문제점들을 해결하는 것이 우리나라 사이버 무역을 할성화시키는데 중요하며 각 항목별로 그 해결방안을 제시해 본다.

심인성 색전 요인이 없는 뇌경색 환자에서 경식도 심초음파와 Acoustic Quantification을 이용한 대동맥 탄성의 평가

이종민,윤호중,임효영,박지원,김휘열,전희경,문건웅,정욱성,채장성,김재형,최규보,홍순조 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.8

효과적인 다차원 분석을 지원하는 스트레드시트 방식의 OLAP 인터페이스 설계 및 구현

윤민희,김진호,문양세 강원대학교 정보통신연구소 2006 정보통신논문지 Vol.10 No.-

OLAP systems support effectively data analysis over a large volume of business data to make decisions for an enterprise. In order to process data analysis efficiently, OLAP systems pre-compute the summary of business data over various dimensions and store them into data warehouses. Several specialized tools have been developed to display and to browse the results of complex analytical queries on data warehouses. In this paper, we developed a spreadsheet-like tool to support OLAP operations and to browse the results of analytical queries. Spreadsheet is one of the most popular and user-friendly data analysis tool. It also has lots of advantages, which is interactive, easy to learn, etc. Thus this paper implemented an OLAP tool using spreadsheet-style interface to analyze large OLAP data on World-Wide Web. Through this tool, users can process OLAP activities easily and effectively by using the same ways as well-known shreadsheet tools like Microsoft Excel.

효과적인 다차원 분석을 지원하는 스프레드시트 방식의 OLAP 인터페이스 설계 및 구현

윤민희,김진호,문양세 강원대학교 정보통신연구소 2006 정보통신논문지 Vol.10 No.-

OLAP systems support effectively data analysis over a large volume of business data to make decisions for an enterprise. In order to process data analysis efficiently, OLAP systems pre-compute the summary of business data over various dimensions and store them into data warehouses. Several specialized tools have been developed to display and to browse the results of complex analytical queries on data warehouses. In this paper, we developed a spreadsheet-like tool to support OLAP operations and to browse the results of analytical queries. Spreadsheet is one of the most popular and user-friendly data analysis tool. It also has lots of advantages, which is interactive, easy to learn, etc. Thus this paper implemented an OLAP tool using spreadsheet-style interface to analyze large OLAP data on World-Wide Web. Through this tool, users can process OLAP activities easily and effectively by using the same ways as well-known shreadsheet tools like Microsoft Excel.

中國 私立大學 營利에 關한 硏究

장덕강,주회민 원광대학교 대학원 2007 論文集 Vol.39 No.-

With the popularization of higher education in China, the private university, as a fresh troop has brought up a large number of talents for our society, and thus attracted more and more attentions from the government and various circles of the society. Private universities have made great contributions to the diversification of the managements of higher education. With the development of economy and the advent of the society, higher education, as a standard public product, has been highly valued and supported by the nation. In particular, private university education is paving a good way for the solution to the lack of funds in Chinese higher education. The chance for private university to make profits can help to increase the possibilities of active investments ineducation from companies, enterprises and individuals, to enlarge the scale of private education, and to achieve fairness and equality of education and finally to promote the prosperity of economy and stability of the society. The author in this article aims to demonstrate that in order to guarantee their education quality, private universities should improve their financial system, consult the management system of the businesses, adopt modernized teaching techniques and perfect teaching capacities of the professors, and thus it can exert a great influence on China.