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Semisynthesis and Cytotoxicity Evaluation of a Series of Ocotillol Type Saponins and Aglycones from 20（S）-Ginsenoside Rg2, Rhl, Protopanaxatriol and Their 20（R）-Epimers

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Chemical Research in Chinese Universities 2016年第1期32卷 35-40页

作者： YANG Jie YU Xue CAI Xiaoxiang CHEN Yanxin ZANG Huiming li xuwen JIN Yongri College of Chemistry Jilin University Changchun 130021 P. R. China College of Life Sciences Jilin University Changchun 130012 P. R. China Hangzhou Innovative Chinese Medicine Standardization Research Institute Co. Ltd. Hangzhou 310053 P. R. China

Abstract With the oxidation treatment, eighteen compounds were separated from 20（S）-ginsenoside Rg2, Rhl, pro- topanaxatriol（PPT） and their 20（R）-epimers in total and cytotoxicity of most of them was evaluated against three hu- man cancer cell lines HeLa, A549 and MCF-7 by 3-（4,5-dimetylthiazol-z-yl）-2,5-diphenyltetrazolium bromide（MTT） assay. Their structures were confirmed by means of nuclear magnetic resonance（NMR） and mass spectrometry and the results were compared with those of previous literature. In this study, we systematically semisynthesized all four ocotillol type saponins, i.e., （20S, 24S＇）, （20S, 24R）, （20R, 24S） and （20R, 24R）. All the configurations at C20 kept the same with their starting materials. Meanwhile a pair of C24 epimers was generated in terms of ocotillol type saponins In addition, seven compounds（4--8, 13 and 14） were reported firstly. The cytotoxic results distinguished the ocotillol type products（6, 7, 13 and 14） from 20（R）-PPT and 20（R）-ginsenoside Rhl, which possessed better cytotoxicities than their correspondents from 20（S）-epimers against HeLa cells, and the carbonyl group at C3 can improve the cytotoxi- city, which helped us to gain deeper insight into Ocotillol type saponins.

关键词： Semisynthesis Ocotillol Saponin Cytotoxicity

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In Vitro Study of the Binding of Taxifolin to Bovine Serum Albumin and the Influence of Common Ions on the Binding

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JOURNAL OF SOLUTION CHEMISTRY 2010年第4期39卷 482-494页

作者： Shi, Xiaolei li, xuwen Sun, Yantao Wei, Wei Yang, Ruijie Zhang, Hanqi Jin, Yongri Jilin Univ Coll Chem Changchun 130012 Peoples R China

The interaction between taxifolin and bovine serum albumin (BSA), and the effects of some common ions on their interaction, were investigated by fluorescence and UV-visible absorption spectroscopy. The results indicate that taxifolin has a strong ability to quench the intrinsic fluorescence of BSA through a static quenching process. According to values of the thermodynamic parameters, the hydrophobic force plays a major role in the interaction. Based on FAster's non-radiation theory, the energy transfer distances between BSA and taxifolin in the absence and presence of some common ions were obtained. The experimental results indicate that the transfer distances are almost unaffected by these ions. The conformation of BSA undergoes significant change from the formation of a taxifolin-BSA complex, which was studied by synchronous and three-dimensional fluorescence spectroscopy.

关键词： Interaction Taxifolin Bovine serum albumin Quenching of fluorescence Common ions

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企业战略变革过程中的冲突影响研究——基于认知的视角

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系统工程理论与实践 2019年第5期39卷 1246-1255页

作者：李旭文齐中英哈尔滨工业大学管理学院哈尔滨150001 中国航天科技集团有限公司北京100048

本研究基于认知的视角,从理论上分析了企业战略变革过程中冲突的形成与影响,提出了战略变革知觉、战略变革响应与冲突关系假设模型,并开展了实证分析.研究表明,战略变革知觉与战略变革响应正相关,冲突在两者之间起到中介作用.

关键词：战略变革冲突认知

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AN IMPROVED INTER-PREDICTION MOTION ESTIMATION ALGORITHM OF AVS

AN IMPROVED INTER-PREDICTION MOTION ESTIMATION ALGORITHM OF ...

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2nd IEEE International Conference on Broadband Network and Multimedia Technology

作者： Wu Qiang Xu Ying Jia Kebin li xuwen Beijing Univ Technol Coll Elect & Control Engn Beijing Peoples R China

ISBN: (纸本)9781424450053

Research on inter-prediction algorithms is an important respect in the real-time video codec technology. In the regarded studies, the prediction error can be reduced by incorporating high accuracy estimation and compensation algorithms. So the performance of compressed video can be improved. However, this brings a considerable cost for the complexity of encoder. The computation complexity is mainly due to the complexity of motion estimation. The paper presents an improved algorithm with the initialized searching point prediction, half-stop principle, beforehand skip mode decision, reduced search window and optional search model. This algorithm for the integer-pixel motion estimation is provided to reduce computation complexity in the block-matching process. Experimental results show that the proposed algorithm can reduce about 64%-73% of computation complexity compared to full search but only with little PSNR degradation.

关键词： AVS inter-prediction motion estimation motion vector block matching

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Adaptive Temporal High-pass Infrared Non-uniformity Correction Algorithm Based on Guided Filter 2021

Adaptive Temporal High-pass Infrared Non-uniformity Correcti...

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7th International Conference on Computing and Artificial Intelligence, ICCAI 2021

作者： Zhang, Y.I. li, xuwen Zheng, Xin Wu, Qiang Beijing University of Technology Beijing China

ISBN: (纸本)9781450389501

In the scene-based infrared focal plane non-uniformity correction algorithm, the temporal high-pass filter non-uniformity correction algorithm is widely cited in various system platforms due to its low hardware platform requirements, but this algorithm is prone to "ghosting"problems and the corrected image still contains certain non-uniformity problems. To solve these problems, this paper proposes an adaptive temporal high-pass filter algorithm based on guided filter. The algorithm uses guided filter to accurately separate high-frequency components containing a large amount of fixed noise and image details, and performs image motion through adjacent frame residual images detection to determine whether to use high-frequency components for iterative operations in the temporal high-pass algorithm, and use the current image detail information to adaptively update the correction parameters of the temporal high-pass filter to avoid the accumulation of image detail information to complete the entire infrared non-uniformity correction . The algorithm in this paper uses actual infrared scene images to compare with the traditional temporal high-pass filter algorithm and bilateral filtering temporal high-pass algorithm. The results show that the algorithm proposed in this paper not only has a good correction effect, but also effectively suppresses the "ghosting"problem. © 2021 ACM.

关键词： High pass filters

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An efficient strategy based on two-stage chromatography and in vitro evaluation for rapid screening and isolation of acetylcholinesterase inhibitors from Scutellaria baicalensis Georgi

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JOURNAL OF SEPARATION SCIENCE 2022年第6期45卷 1170-1184页

作者： Hou, Wanchao liu, Chunming li, Sainan Zhang, Yuchi Jin, Yongri li, xuwen liu, Zhen Niu, Huazhou Xia, Jianli Jilin Univ Coll Chem Changchun Jilin Peoples R China Changchun Normal Univ Cent Lab Changchun Jilin Peoples R China

The extraction of Scutellaria baicalensis Georgi was investigated using the response surface methodology-genetic algorithm mathematical regression model, and the extraction variables were optimized to maximize the flavonoid yield. Furthermore, a simple and efficient ultrafiltration-liquid chromatography-mass spectrometry and molecular docking methods were developed for the rapid screening and identification of acetylcholinesterase inhibitors present in Scutellaria baicalensis Georgi. Subsequently, four major chemical constituents, namely baicalein, norwogonin, wogonin, and oroxylin A, were identified as potent acetylcholinesterase inhibitors. This novel approach, involving the use of ultrafiltration-liquid chromatography-mass spectrometry and molecular docking methods combined with stepwise flow rate counter-current chromatography and semi-preparative high-performance liquid chromatography, could potentially provide a powerful tool for the screening and extraction of acetylcholinesterase inhibitors from complex matrices and be a useful platform for the production of bioactive and nutraceutical ingredients.

关键词： acetylcholinesterase inhibitors countercurrent chromatography mathematical model purification Scutellaria baicalensis Georgi

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Determination of common ginsenosides in Kang'ai injection by aqueous two-phase extraction with deep eutectic solvents and HPLC-UV/DAD

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MICROCHEMICAL JOURNAL 2018年 137卷 302-308页

作者： li, Peng Zhao, Pengyun liu, Weijie Jiang, Yifu Wang, Wenjiao Bao, Longyue Jin, Yongri li, xuwen Jilin Univ Coll Chem Changchun 130012 Jilin Peoples R China

In this work, four kinds of deep eutectic solvents (DESs), composed of choline chloride (ChCl) and several alcohols, were synthesized and characterized by H-1 NMR and FT-IR spectra. Based on DES ( ChCl and 1,4-butanediol) and inorganic salt solution (dipotassium phosphate, K2HPO4), aqueous two-phase system (ATPS) coupled with high-performance liquid chromatography has been developed and applied. This method was used for the efficient extraction and determination of eight common ginsenosides (including ginsenoside Rg(1), Re, Rf, Rg(2), Rc, Rb-2 and Rd) in the traditional Chinese medicine injection named Kang'ai injection. To achieve optimum extraction performance, the experimental conditions were optimized, including type and amount of DES and salt, ultrasound time, temperature and pH value. In the dynamic linearity range, experimental results showed satisfactory recoveries of analytes ranging from 92.7-110.8% with the relative standard deviations (RSDs) ranging from 1.2-3.9%. It has been proved that DES-ATPS has great potential for determination of active ingredients in traditional Chinese medicine injection as well as samples in other analytical science field. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Aqueous two-phase system Ginsenosides High-performance liquid chromatography Kang'ai injection

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Marine sponges of the genus Stelletta as promising drug sources: chemical and biological aspects

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Acta Pharmaceutica Sinica B 2019年第2期9卷 237-257页

作者： Qihao Wu Bastien Nay Min Yang Yeke Ni Hong Wang ligong Yao xuwen li State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences College of Pharmaceutical Science Zhejiang University of Technology Laboratoire de Synthèse Organique UMR 7652 CNRS Ecole Polytechnique Université Paris-Saclay

Marine sponges of the genus Stelletta are well known as rich sources of diverse and complex biologically relevant natural products, including alkaloids, terpenoids, peptides, lipids, and steroids. Some of these metabolites, with novel structures and promising biological activities, have attracted a lot of attention from chemists seeking to perform their total synthesis in parallel to intensive biological studies towards new drug leads. In this review, we summarized the distribution of the chemically investigated Stelletta sponges, the isolation, synthesis and biological activities of their secondary metabolites, covering the literature from 1982 to early 2018.

关键词： Marine natural products Stelletta sponge Isolation Total synthesis Biological activity Marine drug leads

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In-Situ Transformed Ni, S-Codoped CoO from Amorphous Co-Ni Sulfide as an Efficient Electrocatalyst for Hydrogen Evolution in Alkaline Media

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ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2019年第14期7卷 12501-12509页

作者： Lu, Wangting li, xuwen Wei, Feng Cheng, Kun li, Wenhui Zhou, Youhua Zheng, Wanquan Pan, Lei Zhang, Geng Jianghan Univ Inst Interdisciplinary Res 8 Sanjiaohu Rd Wuhan 430056 Hubei Peoples R China Jianghan Univ Sch Chem & Environm Engn 8 Sanjiaohu Rd Wuhan 430056 Hubei Peoples R China Univ Paris Saclay Univ Paris Sud CNRS Inst Sci Mol Orsay F-91405 Orsay France Jianghan Univ Sch Life Sci 8 Sanjiaohu Rd Wuhan 430056 Hubei Peoples R China Huazhong Agr Univ Coll Sci Dept Chem 1 Shizishan St Wuhan 430070 Peoples R China

Amorphous materials have recently received much attention as catalysts for electrochemical reactions. However, there are relatively few reports focused on the structure change of amorphous catalysts during the catalysis process, although this is quite important to the identification of active species and in revealing the reaction mechanism. Herein, amorphous Co-Ni sulfide in the form of a nanoplate and nanowire hybrid on the surface of nickel foam is prepared as the electrode for the hydrogen evolution reaction (HER). During the hydrogen evolution process, the amorphous Co-Ni sulfide is in-situ transformed into crystalline Ni, S-co-doped CoO which is actually responsible for the catalysis of HER The transformation process is studied in detail by high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and theoretical calculations. The in-situ formed electrode presents a high activity and durability toward HER in alkaline media. The Ni and S dopants, sulfurization temperature, and electrode substrate are revealed to be important factors that affect the activity. The present work will not only give more insights in the structure evolution of the electrocatalyst during HER but also provides a new strategy to the fabrication of new electrocatalysts.

关键词： Water splitting HER Amorphous material Oxide Doping

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Studies on interaction between flavonoids and bovine serum albumin by spectral methods

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JOURNAL OF LUMINESCENCE 2010年第4期130卷 637-644页

作者： Shi, Xiaolei li, xuwen Gui, Mingyu Zhou, Hongyu Yang, Ruijie Zhang, Hanqi Jin, Yongri Jilin Univ Coll Chem Changchun 130012 Peoples R China

The interaction between three kinds of flavonoids and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis absorption spectrometry. The results indicated that flavonoids have strong ability to quench the intrinsic fluorescence of BSA by forming complexes. The binding constants, number of binding sites, thermodynamic parameters and energy transfer mechanisms were also investigated. Conformation change of BSA was observed from Synchronous, three-dimensional fluorescence and circular dichroism spectrum. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Flavonoids Bovine serum albumin Three-dimensional fluorescence spectra Synchronous fluorescence spectra Circular dichroism spectrum

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