Lipolysis Effect of Daucosterol Isolated from Mulberry (Morus alba) Leaves

Ke Li1(이커),Mi Lim Lee(이미림),Lu Que(루쿼),Mae Li(이매),Jum Soon Kang(강점순),Yung Hyun Choi(최영현),Kyung Mi Kim(김경미),Jae-Chul Jung(정재철),Dae Youn Hwang(황대연),Young Whan Choi(최영환) 한국생명과학회 2017 생명과학회지 Vol.27 No.12

뽕나무는 약 40여 속과 1,000여 종이 있는 것으로 알려져 있으며, 항염증, 항진정, 지사작용, 노화억제 및 신경보호작용이 있는 것으로 알려져 있다. 본 연구에서는 아시아 지역에서 전통 한약재로 사용되는 뽕 나무 잎의 지방분해 활성에 관여하고 있는 물질을 스크린하기 위하여 뽕잎 분말을 헥산, 에틸 아세테이트 및 메탄올로 순차 추출하였다. 뽕 잎의 EtOAc 추출물로부터 daucosterol이 순수분리 되었으며, 그 구조는 1H, 13C, DEPT, COSY, HSQC 및 HMBC 등의 NMR스펙트럼 분석에 의해 밝혀졌다. Daucosterol은 농도 의존적으로 지질분해 효과를 나타내었는데, 본 연구의 결과로부터 뽕나무 잎으로부터 순수분리한 daucosterol의 지분분해 활성은 다양한 질병을 치료하기 위한 천연물 소재 또는 지표성분으로서 활용이 가능할 것으로 생각된다. 그러나 보다 효율적으로 이용하기 위해서는 daucosterol의 비만에 관한 생리활성 기작에 대한 추가적인 연구가 필요할 것이다. Plants are reservoirs of naturally occurring chemical compounds and of structurally diverse bioactive molecules. The aim of this investigation was to screen for the presence of phytochemicals responsible for the lipolysis activity in mulberry (Morus alba) leaves, which are important in traditional Asian medicinal plants. Powdered mulberry leaves were extracted with hexane, ethyl acetate, and methanol. Daucosterol was isolated from the EtOAc extract of mulberry leaves, and its structure was elucidated by NMR spectral analyses. The NMR assignments for the compound were determined using 1H, 13C, DEPT, COSY, HSQC, and HMBC NMR spectral data. Daucosterol showed a concentration-dependent lipolysis activity that may impart medicinal properties that can be exploited by medical practitioners for the treatment of various diseases. However, further studies should be conducted to elucidate additional mechanisms of daucosterol.

Biochar-supported nZVI (nZVI/BC) for contaminant removal from soil and water: A critical review

Wang, Shengsen,Zhao, Mingyue,Zhou, Min,Li, Yuncong C.,Wang, Jun,Gao, Bin,Sato, Shinjiro,Feng, Ke,Yin, Weiqin,Igalavithana, Avanthi Deshani,Oleszczuk, Patryk,Wang, Xiaozhi,Ok, Yong Sik Elsevier 2019 Journal of hazardous materials Vol.373 No.-

<P><B>Abstract</B></P> <P>The promising characteristics of nanoscale zero-valent iron (nZVI) have not been fully exploited owing to intrinsic limitations. Carbon-enriched biochar (BC) has been widely used to overcome the limitations of nZVI and improve its reaction with environmental pollutants. This work reviews the preparation of nZVI/BC nanocomposites; the effects of BC as a supporting matrix on the nZVI crystallite size, dispersion, and oxidation and electron transfer capacity; and its interaction mechanisms with contaminants. The literature review suggests that the properties and preparation conditions of BC (e.g., pore structure, functional groups, feedstock composition, and pyrogenic temperature) play important roles in the manipulation of nZVI properties. This review discusses the interactions of nZVI/BC composites with heavy metals, nitrates, and organic compounds in soil and water. Overall, BC contributes to the removal of contaminants because it can attenuate contaminants on the surface of nZVI/BC; it also enhances electron transfer from nZVI to target contaminants owing to its good electrical conductivity and improves the crystallite size and dispersion of nZVI. This review is intended to provide insights into methods of optimizing nZVI/BC synthesis and maximizing the efficiency of nZVI in environmental cleanup.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Aggregation and passivation of nZVI can be alleviated by surfactants and doping methods. </LI> <LI> BC hinders corrosion and improves the dispersion and electron transfer of nZVI. </LI> <LI> Properties of nZVI depend on those of the BC, feedstock and pyrogenic temperature. </LI> <LI> BC enhances electron transfer from nZVI to the contaminants due to the presence of quinone and graphene moieties. </LI> <LI> nZVI/BC shows strong ability to remove HMs, nitrates, and organic contaminants in soil and water. </LI> </UL> </P>

Ash formation characteristics of two Indonesian coals and the change of ash properties with particle size

Ke, Xiwei,Li, Dongfang,Zhang, Man,Jeon, Chung-hwan,Cai, Runxia,Cai, Jin,Lyu, Junfu,Yang, Hairui Elsevier Scientific Pub. Co. 2019 Fuel processing technology Vol.186 No.-

<P><B>Abstract</B></P> <P>It is difficult to maintain enough high circulating ash rate in circulating fluidized bed (CFB) boilers if they burn the Indonesian coals due to their low ash content. Hence, the ash formation data for these coals is of significance to assessing mass balance in CFB boilers. Two kinds of Indonesian coal that were burned in the 550 MW supercritical CFB boilers in Korea, Kideco and KCH, were tested with static combustion and cold sieving method to study their ash formation characteristics. Results showed that the average primary ash particle size of these two coals is quite fine overall and nearly no gangue exists. Besides, their attrition rate constant <I>K</I> <SUB>af</SUB> is much higher than that of some other bituminous or lean coals, and with the increase of particle size, the <I>K</I> <SUB>af</SUB> decays exponentially for Kideco, while it initially increases and then decreases for KCH. In addition, the physical and chemical properties of these two Indonesian coals' ash obviously change in particle size, including density, pore structure, chemical composition, etc. The larger ash particles are composed of some hard materials, such as quartz (SiO<SUB>2</SUB>) and mullite (Al<SUB>6</SUB>Si<SUB>2</SUB>O<SUB>13</SUB>). While some other materials with lower hardness value, like hematite (Fe<SUB>2</SUB>O<SUB>3</SUB>) and gehlenite (Ca<SUB>2</SUB>Al<SUB>2</SUB>SiO<SUB>7</SUB>), become major mineral components of smaller and softer ash particles. These results indicate that the difference of chemical compositions results in the discrepancy of attrition capability for different size ash particles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two kinds of Indonesian coal were tested to obtain their ash formation data. </LI> <LI> The ash properties obviously change in particle size. </LI> <LI> The difference of chemical compositions may result in the discrepancy of attrition rate for different size ash particles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The ash attrition rate of low-rank coals including these two Indonesian coals is much higher than that of some other bituminous or lean coals, and larger ash particles are more difficult to be worn.</P> <P>[DISPLAY OMISSION]</P>

Stress-induced expression of the sweetpotato gene <i>IbLEA14</i> in poplar confers enhanced tolerance to multiple abiotic stresses

Ke, Qingbo,Park, Sung-Chul,Ji, Chang Yoon,Kim, Ho Soo,Wang, Zhi,Wang, Shiwen,Li, Hongbing,Xu, Bingcheng,Deng, Xiping,Kwak, Sang-Soo Elsevier 2018 Environmental and experimental botany Vol.156 No.-

<P><B>Abstract</B></P> <P>Late embryogenesis abundant (LEA) proteins are small, highly hydrophilic proteins that act as protectors of macromolecules and increase abiotic stress tolerance in plants. We previously reported that overexpressing sweetpotato <I>IbLEA14</I> under the control of the <I>CaMV 35S</I> promoter increased osmotic and salt stress tolerance in transgenic sweetpotato calli. In this study, we generated transgenic poplar plants (<I>Populus alba × P. glandulosa</I>) expressing <I>IbLEA14</I> under the control of the oxidative stress-inducible <I>SWPA2</I> promoter (referred to as SL plants). Among the 15 SL plants obtained, three lines (SL2, SL7, and SL12) were established based on <I>IbLEA14</I> transcript levels, tolerance to salt stress and Southern blot analysis. The SL plants exhibited less damage in response to methyl viologen-mediated oxidative stress than non-transgenic (NT) plants. SL plants also showed enhanced tolerance to drought, salt, and heat stress, which was associated with higher photosystem II efficiency and lower malondialdehyde levels compared with NT plants. Furthermore, SL plants had higher levels of monolignol biosynthesis-related gene transcripts under drought stress compared with NT plants. Finally, SL plants exhibited increased tolerance to heat stress, which is associated with the high thermostability of IbLEA14 protein. SL plants might be useful for reforestation on global marginal lands, including desertification and reclaimed areas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>IbLEA14</I> gene was transformed into poplar plants. </LI> <LI> Transgenic poplars exhibit increased tolerance to MV-mediated oxidative, drought, salt and heat stress. </LI> <LI> Overproduction of IbLEA14 affects lignification and thermostability of transgenic poplars. </LI> </UL> </P>

Overexpression of alfalfa <i>Orange</i> gene in tobacco enhances carotenoid accumulation and tolerance to multiple abiotic stresses

Wang, Zhi,Xu, Weizhou,Kang, Jiyue,Li, Min,Huang, Jin,Ke, Qingbo,Kim, Ho Soo,Xu, Bingcheng,Kwak, Sang-Soo Elsevier 2018 Vol. No.

<P><B>Abstract</B></P> <P>The multifunctional Orange (Or) protein plays crucial roles in carotenoid homeostasis, photosynthesis stabilization, and antioxidant activity in plants under various abiotic stress conditions. The <I>Or</I> gene has been cloned in several crops but not in alfalfa (<I>Medicago sativa</I> L.). Alfalfa is widely cultivated across the world; however, its cultivation is largely limited by various abiotic stresses, including drought. In this study, we isolated the <I>Or</I> gene from alfalfa (<I>MsOr</I>) cv. Xinjiang Daye. The amino acid sequence of the deduced MsOr protein revealed that the protein contained two trans-membrane domains and a DnaJ cysteine-rich zinc finger domain, and showed a high level of similarity with the Or protein of other plants species. The MsOr protein was localized in leaf chloroplasts of tobacco. The expression of <I>MsOr</I> was the highest in mature leaves and was significantly induced by abiotic stresses, especially drought. To perform functional analysis of the <I>MsOr</I> gene, we overexpressed <I>MsOr</I> gene in tobacco (<I>Nicotiana benthamiana</I>). Compared with wild-type (WT) plants, transgenic tobacco lines showed higher carotenoid accumulation and increased tolerance to various abiotic stresses, including drought, heat, salt, and methyl viologen-mediated oxidative stress. Additionally, contents of hydrogen peroxide and malondialdehyde were lower in the transgenic lines than in WT plants, suggesting superior membrane stability and antioxidant capacity of TOR lines under multiple abiotic stresses. These results indicate the <I>MsOr</I> gene as a potential target for the development of alfalfa cultivars with enhanced carotenoid content and tolerance to multiple environmental stresses.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Orange (<I>MsOr</I>) gene from alfalfa was isolated and characterized in transgenic tobacco. </LI> <LI> <I>MsOr</I> gene was localized to chloroplasts and strongly induced by abiotic stresses including drought. </LI> <LI> <I>MsOr</I> expressing tobacco plants showed enhanced tolerance to drought, heat, salt and oxidative stress. </LI> </UL> </P>

Control effect and mechanism investigation on the horizontal flow-isolating plate for PI shaped bridge decks’ VIV stability

Ke Li,Guowei Qian,Yaojun Ge,Lin Zhao,Jin Di 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.28 No.2

Vortex-Induced-Vibration (VIV) is one kind of the wind-induced vibrations, which may occur in the construction and operation period of bridges. This phenomenon can bring negative effects to the traffic safety or can cause bridge fatigue damage and should be eliminated or controlled within safe amplitudes. In the current VIV studies, one available mitigation countermeasure, the horizontal flow-isolating plate, shows satisfactory performance particularly in PI shaped bridge deck type. Details of the wind tunnel test are firstly presented to give an overall description of this appendage and its control effect. Then, the computational-fluid-dynamics (CFD) method is introduced to investigate the control mechanism, using two-dimensional Large-Eddy-Simulation to reproduce the VIV process. The Reynolds number of the cases involved in this paper ranges from 1×〖10〗^5 to 3×〖10〗^5, using the width of bridge deck as reference length. A field-filter technique and detailed analysis on wall pressure are used to give an intuitive demonstration of the changes brought by the horizontal flow-isolating plate. Results show that this aerodynamic appendage is equally effective in suppressing vertical and torsional VIV, indicating inspiring application prospect in similar PI shaped bridge decks.

Design of Active Measurement System for Voltage Transformer Error Test

Li, Ye,Kai-Qi, Shu,Li, Shen,Si-Ke, Wang 대한전기학회 2014 The Journal of International Council on Electrical Vol.4 No.4

In order to adapt to the error test of the field voltage transformer, solve the problems of the current measuring method, this paper presents the way of using computer control instead of manual control to measure voltage transformer error actively based on WiFi, automatic measure the actual load of the boost circuit, real-time monitoring of the circuit parameters and protection control. At the same time, It realized the whole process information management of measured data, from automatic colletion, analyze to saving, greatly improve of the safety and the efficiency of the work.

Enhanced Visible-Light Driven Photocatalytic Performances Over LaFeO3/NiO Modified Porous g-C3N4 Nanosheets

Ke Xu,Xiaosheng Yang,Dagao Sun,Xin Yang,Yumei Zhou,Wei Li,Qindan Yang,Xianjiong Yang,Rong Li,Jian Feng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.02

LaFeO3/NiO modified g-C3N4 nanosheets (L-N/CNS) were synthesized by a two-step method. HRTEM results showed that an intimate contact between LaFeO3, NiO and N-CNS was successfully established. Ninety percent of phenol was degraded within 120 min, and the hydrogen evolution rate of 171.2 μmol h -1 g -1 was obtained over the L-N/CNS heterojunctions under the visible-light irradiation. It was higher than that of g-C3N4 nanosheets, NiO modified g-C3N4 and LaFeO3/g-C3N4. The ·O2 - radicals acted the crucial role in the photocatalytic degradation reaction. EIS, PL and time-resolved fluorescence spectra demonstrated that L-N/CNS possessed the highest charge separation efficiency. The intimate contact between LaFeO3, NiO and g-C3N4 nanosheets promoted the separation and transfer of photo-induced electron–hole pairs and consequently prolonged the exciton lifetime, and implied more photo-induced electrons could be probably involved in the photocatalytic reactions on the surface of photocatalysts. Thus, the visible-light driven photocatalytic performances of L-N/CNS were effective. This work provided a feasible method to design and construct heterostructures for the exploitation of solar energy.

Tools Setting of 5 Axis Ultra-Precision Single point Diamond Lathe without OTS

Ke-Tian Li,Xin Chen,Xin-Du Chen,Qiang Liu,Xiang-bo Ouyang,Hong-Jian Xia,Jian-Qun Liu 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.9(2)

Six new dammarane-type triterpene saponins from Panax ginseng flower buds and their cytotoxicity

Li, Ke-Ke,Li, Sha-Sha,Xu, Fei,Gong, Xiao-Jie The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.2

Background: Panax ginseng has been used for a variety of medical purposes in eastern countries for more than two thousand years. From the extensive experiences accumulated in its long medication use history and the substantial strong evidence in modern research studies, we know that ginseng has various pharmacological activities, such as antitumor, antidiabetic, antioxidant, and cardiovascular system-protective effects. The active chemical constituents of ginseng, ginsenosides, are rich in structural diversity and exhibit a wide range of biological activities. Methods: Ginsenoside constituents from P. ginseng flower buds were isolated and purified by various chromatographic methods, and their structures were identified by spectroscopic analysis and comparison with the reported data. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H- tetrazolium bromide method was used to test their cytotoxic effects on three human cancer cell lines. Results: Six ginsenosides, namely 6'-malonyl formyl ginsenoside F₁ (1), 3β-acetoxyl ginsenoside F₁ (2), ginsenoside Rh₂₄ (6), ginsenoside Rh₂₅ (7), 7β-hydroxyl ginsenoside Rd (8) and ginsenoside Rh₂₆ (10) were isolated and elucidated as new compounds, together with four known compounds (3-5 and 9). In addition, the cytotoxicity of these isolated compounds was shown as half inhibitory concentration values, a tentative structure-activity relationship was also discussed based on the results of our bioassay. Conclusion: The study of chemical constituents was useful for the quality control of P. ginseng flower buds. The study on antitumor activities showed that new Compound 1 exhibited moderate cytotoxic activities against HL-60, MGC80-3 and Hep-G2 with half inhibitory concentration values of 16.74, 29.51 and 20.48 μM, respectively.