Quantitative analysis of cordycepin in Cordyceps militaris under different extraction methods

( Jungwon Choi ),( Leo Adrianne Paje ),( Baekjun Kwon ),( Jaekyu Noh ),( Sanghyun Lee ) 한국응용생명화학회(구 한국농화학회) 2021 Journal of Applied Biological Chemistry (J. Appl. Vol.64 No.2

Cordyceps militaris (CM) is one of the most important medicinal mushrooms known to possess various biological activities. Cordycepin (CP) is a bioactive compound present in the fruiting bodies of CM and is known to have anti-tumor, anti-metastatic immunomodulatory and anti-inflammatory activities. In this study, we aim to analyze CP quantitatively under various CM extraction conditions. CP was measured using high-performance liquid chromatography, quantified using a reversed phase column using a gradient elution system of water and acetonitrile, and detected with a UV absorbance wavelength of 260 nm. The CP content of CM was the highest in 100% ethanol extract of the fruiting bodies and 60% ethanol extract of the mycelium. This study provides an efficient analysis method to determine the optimal extraction conditions for CP that can be used as a basis for developing functional foods and pharmaceutical products derived from CM.

Resource Allocation for H-FDD OFDMA Systems

Choi, Jihwan P.,Jaesub Shin,Jungwon Lee,Hui-Ling Lou,Ji-Woong Choi IEEE 2014 IEEE communications letters Vol.18 No.7

<P>Half-frequency-division duplexing (H-FDD) has recently attracted attention since it can serve as a cost-effective solution for machine-to-machine (M2M) communication networks. This letter proposes a method to jointly optimize resource allocation, mobile station grouping, and frame partitioning for H-FDD orthogonal frequency-division multiplexing access systems. We develop a near-optimal and low-complexity algorithm that is also applicable to frequency-division duplexing and time-division duplexing as special cases. Simulation results demonstrate that our algorithm with reduced computation can provide performance close to that of the optimal but time-consuming exhaustive search.</P>

Antioxidative phenolic compounds from the aerial parts of Cyperus exaltatus var. iwasakii and their HPLC analysis

Choi Jungwon,Lee Hak-Dong,Cho Hyejin,Lee Chang-Dae,Tran Gia Han,Kim Hoon,Moon Sung-Kwon,Lee Sanghyun 한국응용생명화학회 2023 Applied Biological Chemistry (Appl Biol Chem) Vol.66 No.-

The constituents and antioxidant activities of Cyperus exaltatus var. iwasakii (CE) have not been studied to date. In this study, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6 sulfonic acid) (ABTS) assays were used to evaluate the radical-scavenging activities of the ethanol extract, four fractions, and isolated compounds of CE. In addition, phenolic acids and flavonoids were isolated from the ethanol extract of CE using column chromatography. The compounds identified by spectroscopy were gallic acid, protocatechuic acid, vanillic acid, p-coumaric acid, rutin, ferulic acid, isoquercitrin, astragalin, quercetin, luteolin, apigenin, tricin, and kaempferol. Quantitative analysis using high-performance liquid chromatography (HPLC) revealed that the major flavonoids of CE were astragalin and tricin and that the major phenolic acid was p-coumaric acid. In addition, comparative analysis of CE from Ganghwa and Hampyeong habitats using HPLC showed that the Hampyeong CE had a higher phytochemical content. Comparative analyses of the isolated compounds were also conducted among five Cyperus species. The highest antioxidant activities were found in the ethyl acetate (EtOAc) fraction, and among the compounds isolated from CE, vanillic acid and quercetin showed remarkable antioxidant activity even when compared with ascorbic acid. The results demonstrate the usefulness of CE, which has not been sufficiently studied previously, and will facilitate the evaluation of its potential effectiveness as antioxidant functional plant material.

Simultaneous determination of saikosaponin derivatives in Bupleurum falcatum by HPLC-ELSD analysis using different extraction methods

( Jungwon Choi ),( Juree Kim ),( Sam Sik Kang ),( Sanghyun Lee ) 한국응용생명화학회(구 한국농화학회) 2021 Journal of Applied Biological Chemistry (J. Appl. Vol.64 No.1

Saikosaponin derivatives such as saikosaponins A, B1, B2, B3, B4, C, and D present in Bupleurum falcatum were analyzed by a high performance liquid chromatograph equipped with an evaporative light scattering detector, using different extraction solvents (water and 70% ethanol). The samples were injected into a YMC Pack Pro C₁₈ column and separated using a gradient elution system with a mobile phase composed of acetonitrile and water at a flow rate of 1.1 mL/min. The content of saikosaponin derivatives was higher in 70% ethanol extract than in water extract. This study provides an efficient analytical method for determining the optimal conditions for extraction of saikosaponin derivatives, which can be used as a basis for development of functional foods and pharmaceutical products from B. falcatum.

A Study on an Experience Exhibition Space for the Hearing-disabled using Ubiquitous Technology

Jungwon Choi,Hyunsuk Son,Yongseong Kim 한국콘텐츠학회 2009 ICCC International Digital Design Invitation Exhib Vol.2009 No.12

Modern Korea beings are more likely to pay attention to and spend time in leisure activities amid rapidly changing economic growth. However, unluckily, there are less cultural facilities and feasible plans for the disabled in spite of more efforts to set up environments for them. The purpose of this study is to present an exhibition space where the hearing-disabled can experience for themselves and meet their needs through applying ubiquitous technology. With ubiquitous technology applied for the disabled and to the space, auditory data could be imagined via visual means. This study presented a space where the handicapped can have more optimized experiences by applying ubiquitous technology while enhancing their limited hearing ability form visual and tactile means, in order to get information on sounds and rhythms.

Crystal structure of the C107S/C112S mutant of yeast nuclear 2-Cys peroxiredoxin

Choi, Jongkeun,Choi, Soonwoong,Chon, Jae Kyung,Choi, Jungwon,Cha, Mee-Kyung,Kim, Il-Han,Shin, Whanchul Wiley Subscription Services, Inc., A Wiley Company 2005 Proteins Vol.61 No.4

Development of an Analytical Approach for the Utilization of Edible Tree Sprouts

Jungwon Choi,김주리,이학동,조혜진,Leo Adrianne Paje,Hanna Shin,이상현 한국생약학회 2022 Natural Product Sciences Vol.28 No.1

This study evaluated the general nutritional ingredients such as crude fats, crude ashes, crude proteins, total polyphenols, and total flavonoids in 18 kinds of edible tree sprouts. The tree sprouts of Philadelphus schrenckii, Lycium chinense, and Morus alba had the highest crude fat, crude ash, and crude protein content, respectively. The tree sprouts of Cedrela sinensis (CSS) with high ABTS+ radical scavenging activities had a high content of total polyphenols (175.65 mg/g ext.) and total flavonoids (75.18 mg/g ext.). The simultaneous determination of flavonoids such as rutin, isoquercitrin, quercitrin, afzelin, and quercetin in CSS was conducted using high-performance liquid chromatography with a wavelength of 270 nm. Among the flavonoids, the content of quercitrin in CSS was the highest at 59.28 mg/g ext. This study also aids the quality control of many edible tree sprouts by analyzing the general components, total polyphenols, and total flavonoids.

REP1 Modulates Autophagy and Macropinocytosis to Enhance Cancer Cell Survival

Choi, Jungwon,Kim, Hyena,Bae, Young Ki,Cheong, Heesun MDPI 2017 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.18 No.9

<P>Rab escort protein 1 (REP1), a component of the Rab geranyl-geranyltransferase 2 complex, plays a role in Rab protein recruitment in proper vesicles during vesicle trafficking. In addition to having well-known tissue degenerative phenotypes in the REP1 mutant, REP1 is tightly associated with cancer development and contributes to cell growth and survival. However, the functional mechanism of REP1 in cancer progression is largely uninvestigated. Here, we show that REP1 plays a crucial role in regulating mammalian target of rapamycin (mTOR) signaling and its downstream pathways, as well as autophagy and macropinocytosis, which are essential for cancer cell survival during metabolic stresses including starvation. REP1 small interfering RNA (siRNA) treatment downregulates mTORC1 activity in growing media, but blocks autophagosome formation under nutrient-depleted conditions. In contrast to the mild decrease of lysosomal enzyme activity seen in REP1 depletion, in REP1 knockdown the subcellular localization of lysosomes is altered, and localization of REP1 itself is modulated by intracellular nutrient levels and mTOR activity. Furthermore, REP1 depletion increases macro pinocytosis which may be a feedback mechanism to compensate autophagy inhibition. Concomitant treatment with macropinocytosis inhibitor and REP1siRNAresults in more significant cell death than autophagy blockade with REP1 knockdown. Therefore, REP1-mediated autophagy and lysosomal degradation processes act as novel regulatory mechanisms to support cancer cell survival, which can be further investigated as a potential cancer-targeting pathway.</P>

국립과학관 효율성 평가지표에 대한 통합적 연구

최정원(Jungwon Choi),남태우(Taewoo Nam) 한국전시산업융합연구원 2018 한국과학예술융합학회 Vol.34 No.-

본 연구는 과학관을 가장 잘 아는 내부 직원의 의견을 최대한 반영하여 국립과학관 평가지표를 개선하고자 시작되었다. 본 연구의 목적은 국립과학관 기관평가지표에 대한 체계적 분석 결과를 토대로 하여 공공전시서비스의 효율성을 제고할 수 있는 평가지표를 개선하는 것이다. 따라서 본 논문은 전국 5대 국립과학관에 5년 이상 근무한 직원을 대상으로 기관 평가지표 관련 AHP 분석을 시도하였고, 효율성 증진을 위한 지표의 우선순위와 중요도를 통합적으로 살펴보았다. 연구결과 및 내용은 다음과 같다. 첫째, ‘전시’, ‘교육’, ‘문화행사’, ‘경영’ 분야 순으로 우선순위가 높게 나타났고, 특히 전시분야 중 ‘전시품 품질’, ‘전시 중장기 계획’, ‘전시 전문 인력 수’ 순으로 우선순위와 중요도가 높았다. 둘째, 책임운영기관과 법인기관으로서 과학관의 효율성 평가 지표에서 어떤 차이가 있는지를 조사하였는데, 법인기관의 경우 ‘경영’ 분야가 ‘문화행사’ 분야보다 우선순위가 높게 도출되었다. 이러한 연구결과를 바탕으로 전시 품질, 교육 품질 등 과학관 콘텐츠의 품질 향상을 위한 지표와 전문 인력수 지표가 통합적으로 평가 지표에 반영되어야 기관의 효율성을 증진시킬 수 있음을 말해준다. This study was initiated to improve the national science museum assessment metrics by reflecting the opinions of internal workers. The purpose of this study is to improve the evaluation indicators that can increase the efficiency of public exhibition services based on integrated analysis results of the agency evaluation indicators. Therefore, this paper attempted to analyze the analytic hierarchy process(AHP) for the five or more years of staff working at the five national science museums nationwide, and looked at the priorities and importance of the indicators in order to improve efficiency. The research results and contents are as follows. First, the priority was high in terms of ‘exhibition’, ‘education’, ‘cultural event’, and ‘management’ sectors, especially in the ‘exhibition quality’, ‘exhibition mid·long-term plan’ and ‘the number of exhibition experts’. Second, it investigated the differences in the efficiency assessment indexes of science museums as executive agencies and corporate agencies. In case of a corporate agencies, the ‘management’ field was given higher priority than in the ‘cultural event’ field. Based on these research results, indicators for improving the quality of science museums contents, such as wartime quality and education quality, and the number of experts should be integrally applied to the evaluation indicators to enhance the efficiency of agencies.

픽토그램의 연상 색채에 따른 친숙도와 심미성 평가

최정원(Choi, JungWon),박영경(Park, YungKyung),최경실(Choi, GyoungSil) 한국색채학회 2022 한국색채학회 논문집 Vol.36 No.2

Previous studies have shown that the more familiar the pictogram’s shape is, the more attractive it is. To find out whether these results can be applied to color, this study analyzed the color of pictogram’s familiarity and aesthetics. First, we conducted a pre-questionnaire to evaluate the familiarity of pictograms and to investigate the associated color. Therefore eleven pictograms with high familiarity were selected. Second, those pictograms were divided into two groups, one with six pictograms that associated with specific color, and the other with five pictograms that are not associated with specific color. In this experiment, 13 colors (R, YR, Y, GY, G, BG, B, PB, RP, PK, BK, Wh) were applied to the pictograms, and subjects were asked to select familiar color and aesthetic color separately. The study showed that there is a tendency that familiarity and aesthetics of color tend to appear similar, whether pictograms have associated color or do not have associated color. In the case of pictograms that associated with specific color, the colors can be used to make pictograms more familiar and aesthetic. On the other hand, when pictograms are not associated with specific color, there is a tendency that applying Black rather than chromatic color makes pictograms more familiar and aesthetic. According to these results, if objects of pictograms have associated color, it is recommended to use chromatic color that form association with objects. And if objects of pictograms don’t have associated color, black is recommended.