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Chemical Research in Chinese Universities 2005年第3期21卷 274-279页

作者： XUJia-xi ZUOGang LIANGBo KeyLaboratoryofBioorganicChemistryandMolecularEngineeringofMinistryofEducation DepartmentofChemicalBiologyCollegeofChemistryandMolecularEngineeringPekingUniversity

Mass spectrometric behaviour of 2,2a,3,4-tetrahydro-4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide and 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide have been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. The monooxide derivatives showed a tendency to eliminate an alkene or an oxygen atom. 1H-Azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide could also eliminate the thiophen-2-ylketene molecule via a reverse [2+2] cycloaddition. 2,3-Dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide could eliminate SO_2 or SO, respectively. The structure of 2,2a,3,4-tetrahydro-4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide was identified on the basis of its fragmentation. The identification was supported by the fragmentations of model compound, 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide.

关键词： 1H-Azeto[2,1-d]benzothiazepin-1-one 1,5-Benzothiazepine Lactam Mass spectrometry

The Purification of Glucose Type Glycosyl Nitrate and the Synthesis of Spacer-armed N-Acetyllactosamines and Their Dimers

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Chinese Chemical Letters 2002年第4期13卷 303-305页

作者： QingLI HuoLI 等 departmentofchemicalbiology SchoolofPharmaceuticalSciencesandNationalResearchLaboratoryofNaturalandBiomimeticDrugsPekingUniversityBeijing100083 departmentofchemicalbiology SchoolofPharmaceuticalScie

di-O-acetyl-4-O-(2, 3, 4, 6-tetra-O-acetyl-b-D-galactopyranosyl)-2-azido-2-deoxy- b-D-glucoppyranosyl nitrate could be separated from its mannose type isomer by glycosylation according to the reactivity difference of these two compounds. The pure glucose type nitrate can be converted to corresponding trichloroacemidate, which reacted with spacer arms in solution of CH2Cl2 with BF3稥t2O as promoters to give desired glycosides and dimers.

关键词： Glycosyl nitrate glycosyl trichloroacemidate spacer-armed dimer.

Synthesis of RGD-aPEG-lactoside, a Potential Anti-metastasis Glycoconjugate

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Chinese Chemical Letters 2004年第5期15卷 532-534页

作者： ShuChunLI LiMinNIU HuiLI,ZhongJunLI QingLI departmentofchemicalbiology SchoolofPharmaceuticalSciencesandNationalResearchLaboratoryofNaturalandBiomimeticDrugsPekingUniversityBeijing100083

The adhesive interaction between tumor cells and host cells or the extra cellular matrix plays a crucial role in metastasis. Due to the anti-metastasis effects of RGD (arginyl-glycyl -aspartic acid) and some oligosac... 详细信息

关键词： RGD lactose PEG anti-metastasis.

Assembly of a Library of Trisaccharides as Mimics of Sialyl Lewis Xvia Random Combination Strategy

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Chinese Chemical Letters 2004年第4期15卷 379-382页

作者： XiangBaoMENG HuiLI QingLI TieMingCHENG ZhongJunLI departmentofchemicalbiology SchoolofPharmaceuticalSciencesPekingUniversityBeijing100083

A small library containing six positional isomers of fucosyl on the modified lactoside backbone as mimics of the Sialyl Lewis X was synthesized via random combinatorial glycosylation, which was charactered by ESI-MS a... 详细信息

关键词： SLe^x selectin oligosaccharide synthesis random combinatorial glycosylation.

An Unusual Reductive Ring-opening Reaction of Phthalimide with Sodium Hydride in DMF

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Chinese Chemical Letters 2004年第7期15卷 777-778页

作者： XiangBaoMENG HuiLI QingLI ZhongJunLI departmentofchemicalbiology SchoolofPharmaceuticalSciencesPekingUniversityBeijing100083

An unusual reductive ring-opening reaction of phthalimide with sodium hydride in anhydrous DMF was observed for the first time. The presumed mechanism was described in detail.

关键词： Phthalimide benzylation reduction ring-opening.

Inhibition of nicotine-DNA adduct formation by polyphenolic compounds in vitro

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Nuclear Science and Techniques 2004年第4期15卷 219-222页

作者： CHENGYan WANGHai-Fang SUNHong-Fang LIHong-Li departmentofchemicalbiology CollegeofChemistyandMolecularEngineeringPekingUniversityBeijing100871

Nicotine [3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Some polyphenolic compounds can suppress the DNA adduction, and hence act as the potential inhibitors of carcinogenesis. In this study, the inhibitory effects of three polyphenolic compounds, curcumin (diferuloylmethane), resveratrol (trans-3, 5, 4-trihydroxystilbene) and tea polyphenols, on the nicotine-DNA adduction have been investigated in vitro using radiolabelled nicotine and liquid scintillation counting (LSC) technique. Also, the inhibition mechanism of these chemopreventive agents in regard to the activity of the biotransformation enzymes, including cytochrome P450 (CYP450), cytochrome b5 (CYb5) and glutathione S-transferase (GST), has been studied. The results demonstrated that these three polyphenols induced marked dose-dependent decrease in nicotine-DNA adducts as compared with the controls. The elimination rate of adducts reached above 46% at the highest dose for all the three agents with 51.6% for resveratrol. Correspondingly, three polyphenols all suppressed CYP450 and CYb5, whereas curcumin and resveratrol induced GST. We may arrive at a point that the three polyphenols are beneficial to prevent the nicotine adduct formation, and thus may be used to block the potential carcinogenesis induced by nicotine.

关键词：尼古丁 DNA加合物抑制作用多酚生物转化酶放射毒理学

Synthesis of a Novel Conjugate of Dibenzoyldiazomethane and Polyamide Containing N-Methylimidazoles

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Chinese Chemical Letters 2004年第4期15卷 392-393页

作者： DanLIU GuYUAN TheKeyLaboratoryofBioorganicChemistryandMolecularEngineering MinistryofEducationDepartmentofChemicalBiologyCollegeofChemistryPekingUniversityBeijing100871

A novel conjugate of dibenzoyldiazomethane and polyamide containing N-methylimida-zoles was synthesized by a chloroform reaction and a DCC/HOBT coupling reaction.

关键词： Dibenzoyldiazomethane polyamide chloroform reaction.

Diastereoselective α-Alkylation of β-Amino Esters: Preparation of Novel α-Substituted β-Amino Esters from α-Amino Acids

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Chinese Chemical Letters 2002年第8期13卷 721-724页

作者： ZhiHuaMA CongLIU 等 KeyLaboratoryofBioorganicChemistryandMolecularEngineeringofMinistryofEducation DepartmentofChemicalBiologyCollegeofChemistryPeckingUniversityBeijing100871 KeyLaboratoryofBioorganicChemistryandMolec

Enantiomerically pure α-substituted β-amino esters were prepared from natural L-α-amino acids through Arndt-Eistert homologation and diastereoselective α-alkylation.

关键词： Diastereoselectivity alkylation b-amino esters. Diastereoselective aAlkylation of bAmino Esters: Preparation of Novel aSubstituted bAmino Esters from aAmino Acids Zhi Hua MA Cong LIU Yong Hua ZHAO Wei LI Jian Bo WANG* Key Laboratory of

Molecular Spectroscopic Study on the Interaction between Heparinand Neutral Red

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Chinese Chemical Letters 2004年第6期15卷 671-674页

作者： LiZHANG NaLI FengLinZHAO KeAnLI KeyLaboratoryofBioorganicChemistryandMolecularEngineeringofMinistryofEducation DepartmentofChemicalBiologyCollegeofChemistryandMolecularEngineeringPekingUniversityBeijing100871

The interaction between heparin and neutral red was investigated by molecular spectroscopic methods. The change of all spectra suggested that positively charged neutral red had interacted with negatively charged heparin. The study of influence factors indicated that electrostatic force and hydrophobic bond might be involved in the interaction. The total binding number per disaccharide unit and intrinsic binding constant were obtained using Scatchard model.

关键词： Spectroscopic interaction heparin neutral red.

The Different Fluorescent Response of Quin 2 to the Binding of Ca^(2+) and La^(3+) and its Application

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Chinese Chemical Letters 2004年第10期15卷 1197-1200页

作者： JianHU XiaoDaYANG KuiWANG departmentofchemicalbiology SchoolofPharmaceuticalSciencesPekingUniversityBeijing100083

The fluorescence spectra of Quin 2, (2-[(2-bis-[carboxymethyl] amino-5-methylphenoxy) methyl]-6-methoxy-8-bis [carboxymethyl] aminoquiniline), a Ca2+ probe, were investigated upon incubation with Ca2+ or La3+. The results showed that binding of La3+ to Quin 2 resulted in different fluorescent spectrum from that of Ca2+. Based on this observation, a fluorescent method was developed for simultaneously determination of the dissociation rates of Ca2+ and La3+ from a Ca-La- calmodulin complex (Ca2La2CaM).

关键词： Quin 2 fluorescence Ca2+ La3+ calmodulin.