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An Improved Method of Total Synthesis of 2-Methoxypodocarpane-8,11,13-triene

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Chinese Chemical Letters 2001年第3期12卷 197-198页

作者： Qiang XIAO yu xin cui Peng Fei TU Department of Natural Medicines School of Pharmaceutical SciencesPeking UniversityBeijing 100083 Department of Chemistry Lanzhou UniversityLanzhou 730000

12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route simple operation and high y... 详细信息

关键词： Synthesis diterpenes 12-methoxypodocarpane-8 11 13-triene cyclization.

Characterizing some gossypol and gossypolone Schiff's bases by studying their fragmentation patterns with electrospray ionization tandem mass spectra

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Chinese Chemical Letters 2009年第6期20卷 716-719页

作者： Long Zhang xing xin Cao Hai Xia Jiang Biao Jiang yu xin cui State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University Beijing 100191 China Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

To investigate the structural form of gossypol and gossypolone Schiff＇s bases, seven relevant Schiff＇s bases were synthesized and the electrospray ionization-tandem mass spectrometry （ESI-MS/MS） with low-energy collision-induced dissociation was used to analyze their fragmentations. A common fragmentation pathway with the loss of RNH2 from those schiff＇s bases quasi-molecular ions was observed and proposed on the basis of their MS/MS spectra data. This common pathway indicated that those Schiff＇s bases existed mainly as the enamine form not the imine form previously showed in most reports.

关键词： Gossypol Schiff's bases Gossypolone Schiff's bases ESI-MS Enamine form Imine form

Simulation study of the performance of the Very Large Area gamma-ray Space Telescope

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Nuclear Science and Techniques 2024年第9期35卷 1-17页

作者： Xu Pan Wei Jiang Chuan yue Shi-Jun Lei yu-xin cui Qiang yuan Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China

The Very Large Area gamma-ray Space Telescope(VLAST)is a mission concept proposed to detect gamma-ray photons through both Compton scattering and electron–positron pair production mechanisms,thus enabling the detection of photons with energies ranging from MeV to *** project aims to conduct a comprehensive survey of the gamma-ray sky from a low-Earth orbit using an anti-coincidence detector,a tracker detector that also serves as a low-energy calorimeter,and a high-energy imaging *** developed a Monte Carlo simulation application of the detector using the GEANT4 toolkit to evaluate the instrument performance,including the effective area,angular resolution,and energy resolution,and explored specific optimizations of the detector *** simulation-based analysis indicates that the current design of the VLAST is physically feasible,with an acceptance above 10 m^(2)sr which is four times larger than that of the Fermi-LAT,an energy resolution better than 2%at 10 GeV,and an angular resolution better than 0.2◦at 10 *** VLAST project promises to make significant contributions to the field of gamma-ray astronomy and enhance our understanding of the cosmos.

关键词： Space astronomy Gamma-ray telescope Calorimeter Monte Carlo simulation

Synthesis and preliminary biological evaluation of the derivatives of O^6-benzylguanine as inactivators of O^6-alkylguanine-DNA alkyltransferase

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Chinese Chemical Letters 2008年第7期19卷 801-804页

作者： Lei Zhang Bing Jia Chang Feng Hu Fan Wang yu xin cui The State Key Laboratory of Natural and Biomimetic Drags School of Pharmaceutical Science Peking University Beijing 100083 PR China Medical Isotope Research Center Peking University Beijing 100083 PR China Medical and Healthy Analysis Center Peking University Beijing 100083 PR China

A series of new O6-BG derivatives （14-21,23-30） were synthesized as inactivators of O6-Alkylguanine-DNA alkyltransferase （AGT）, and their ability to inhibit AGT was preliminary evaluated by MTT with O6-BG as the c... 详细信息

关键词： O^6-BG derivatives AGT inactivator

Characteristic fragmentation behavior of the analogs of endomorphin-2 with phenylglycine in position 3 or 4 by ESI-FT tandem mass spectrometry

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Chinese Chemical Letters 2008年第12期19卷 1479-1482页

作者： Chang Feng Hu Chuan Jun Zhu Yan Feng Gao Xuan Shao Rui Wang yu xin cui State Key Laboratory of Natural and Biomimetic Drugs （Peking University） Beijing 100083 China School of Life Science Lanzhou University Lanzhou 730000 China

A series of analogs of endomorphin-2 （EM-2） with phenylglycine （Phg） in position 3 or 4 were synthesized. In electrospray ionization Fourier transform ion cyclotron resonance （ESI-Fr-ICR） MS/MS spectra of these compounds, some b, y, a, and internal ions were observed and slight mass differences between the calculated and observed results are obtained. Their sequences were derived successfully. However, the MS/MS patterns of these analogs with Dphg and Lphg were very similar. It is hard to distinguish them by MS/MS spectra. Moreover, if the third position was substituted by phenylglycine （L or D）, a rearrangement could occur in MS/MS experiment to lose proline residue.

关键词： Endomorphin-2 Opioid peptide analogs Phenylglycine ESI-FT MS

Functional characterization of a novel, highly expressed ion-driven sugar antiporter in the thoracic muscles of Helicoverpa armigera

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Insect Science 2022年第1期29卷 78-90页

作者： Yi-Yang yuan yu-cui xin Jian-Li Han yu-Han Zhao Shi-Ming Han Zi-Yan Nangong xin Chen Zhu-Cheng Wang Mei Li xing-Hui Qiu State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina College of Life Sciences University of Chinese Academy of SciencesBeijingChina College of Life Sciences Cangzhou Normal UniversityCangzhouJiangsu ProvinceChina College of Plant Protection Hebei Agricultural UniversityBaodingHebei ProvinceChina

Sugar transporters(STs),which mainly mediate cellular sugar exchanges,play critical physiological roles in living organisms,and they may be responsible for sugar exchanges among various insect ***,the molecular and physiological functions of insect STs are largely ***,16 STs of Helicoverpa armigera were identified.A phylogenetic analysis classified the putative HaSTs into 12 sub-families,and those identified in this study were distributed into 6 ***-time polymerase chain reaction indicated that the 16 HaSTs had diverse tissue-specific expression *** transporter,HaST10,was highly expressed in thoracic muscles.A functional study using a Xenopus oocyte expression system revealed that HaST10 mediated both H+-driven trehalose and Na+-driven glucose antiport activities with high transport efficiency and low affinity levels.A HaST10 knockout clearly impaired the performance of ***,HaST10 may participate in sugar-supply regulation and have essential physiological roles in ***.

关键词： CRISPR/Cas9 glucose Helicoverpa armigera sugar transporter trehalose thoracic muscles

Influence of particulate morphology on microstructure and tribological properties of cold sprayed A380/Al2O3 composite coatings

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Journal of Materials Science & Technology 2020年第9期44卷 9-18页

作者： Xiang Qiu Naeem ul Haq Tariq Lu Qi Jun-Rong Tang xin-yu cui Hao Du Ji-Qiang Wang Tian-Ying Xiong Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Department of Metallurgy and Materials Engineering Pakistan Institute of Engineering and Applied SciencesNiloreIslamabadPakistan

In this study,three kinds of A380/Al2O3 composite coatings were prepared by cold spray(CS)using spherical,irregular and spherical+irregular shaped Al2O3 particulates separately mixed in the original A380 alloy *** influence of Al2O3 particulates’morphology on the microstructural characteristics(*** of Al2O3 content in coatings,coating/matrix interfacial bonding,pore size distribution and morphology etc.)and wear performance of the coatings was investigated by scanning electron microscopy(SEM),X-ray computed tomography(XCT)and 3-D optical *** indicated that the spherical Al2O3 showsobvious tamping effect during deposition *** a result,the interfaceshowedawavy shape while the matrix and particulates were mechanical interlocked with much improved *** addition,the porosity of the coating was minimized and the pores exhibited curved spherical structure with reduced *** irregular Al2O3 particles predominantly displayed the embedding effect together with fragmentation of Al2O3 ***,poor coating/matrix interfacial bonding,high porosity and the formation of angular-shaped pores were resulted in the *** sliding wear tests results revealed that the wear resistance of the coating is directly related with the retained content of Al2O3 in the *** coating containing irregular Al2O3 particulates displayed superior wear performance with its wear rate one seventh of that of the pure A380 alloy *** coating containing both kinds of Al2O3 particulates showed mixed characteristics of above two kinds of Al2O3 composite coatings.

关键词： Cold spray Al2O3 particulates X-ray computed tomography Wear test

Two New Triterpenoid Saponins from the Seeds of Aesculus chinensis

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Chinese Chemical Letters 2000年第2期11卷 139-142页

作者： Xiu Wei YANG Jing ZHAO yu xin cui (National Laboratory of Natural and Biomimetic Drugs, Beijing Medical University, Beijing 100083) Natl. Lab. Nat. and Biomimetic Drugs Beijing Medical University Beijing 100083 China

Two new triterpenoid saponins, named isoescins IIIa (1) and IIIb (2) were isolated from the seeds of Aesculus chinensis and identified by spectroscopic analysis and chemical hydrolysis. Their structures were established as 21 beta-tigloyl-28-acetylbarringtogenol C-3 beta-O-[beta D-galactopyranosyl( 1-->2)] [beta-D-glucopyranosyl (1-->])1-beta-D-glucopyranosiduronic acid (1) and 21 beta-angeloyl-28-acetylbarringtogenol C-3 beta-O-[beta-D;galactopyranosyl (1-->2)] [beta-D-glucopyranosyl(1 -->4)]-beta-D-glucopyranosiduronic acid (2), which are geometrically isomeric.

关键词： Aesculus chinensis isoescins IIIa and IIIb

Three New Triterpenoid Saponins from the Seeds of Aesculus chinensis

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Chinese Chemical Letters 1999年第12期10卷 0-0,0-0页

作者： Xiu Wei YANG Jing ZHAO yu xin cui(National Laboratory of Natural and Biomimetic Drugs, Beijing Medical University,Beding 100083) Natl. Lab. Nat. and Biomimetic Drugs Beijing Medical University Beijing 100083 China

Three new triterpenoid saponins, escins IVg (1), IVh (2) and VIb (3) were isolatedfrom the seeds of Aesculus chinensis along with two known saponins, escin IIIa (4) anddesacylescin I (5). Their structures were elucida... 详细信息

关键词： Aesculus chinensis Hippocastanaceae escins Ⅲ4 IVg IVh and Vib desacylescin I.