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POLYMER SCAFFOLDS BEARING AZOBENZENE-POTENTIAL FOR OPTICAL INFORMATION STORAGE

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Chinese Journal of Polymer Science 2001年第2期19卷 147-153页

作者： Sφren Hvilsted P.S.Ramanujam Danish Polymer Centre Chemical Engineering Department Technical University of Denmark DK-2800 Kgs. Lyngby DenmarkOptics and Fluid Dynamics Department Risφ National LaboratoryDK-4000 Roskilde Denmark

The fundamental optical storage mechanism of the laser light eddressable azobenzene moiety is briefly introduced.A modular and flexible synthesis design furnishes polyester matrices covalently integrating cyanoazobenzene in regularlyspaced side chains. Thin films of these materials are particularly well suited for holographic storape. Notable figures of meritsof liquid crystalline polyesters are response time to blue-green laser light of the order of nanoseconds, storage capacityexpressed as 5000 lines/mm, and high, permanent (almost nine years) diffraction efficiency of the order of 50% or greater,and erasability, The implications of the main chain nature for polyester morphology and for the permanency of the inducedanisotropy are discussed, The design and methods of preparation of other significantly different polymer scaffolds supportingcyanoazobenzene are elaborated. oligopeptides always result in amorphous materials, whereas copolymethacrylates anddendritic or hyperbranched polyesters provide some materials that exhibit liquid crystallinity. However, none of these scaffolds affords materials that result in permanent anisotropy when exposed to interfering laser light.

关键词： Azobenzene side-chain polymers Copolymethacrylates Dendrimers Holographic storage LC and amorphous polyesters Morphology oligopeptides

Promoted Comprehensive Properties of Polyisoprene Rubber with Extremely High Fatigue Resistance Enabled by Oligopeptide Aggregates

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Chinese Journal of Polymer Science 2023年第8期41卷 1250-1260,I0008页

作者： Yu He Ran Xu Rong Zhang Chang-Cheng Wang Shi-Qi Li Jian Cao Mao-Zhu Tang Yun-Xiang Xu College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

For decades,the preparation of polyisoprene rubber that can match the comprehensive properties of natural rubber(NR)has been *** sacrificial bonds have been used to promote the strength and toughness of rubbers,little is known about their effects on fatigue resistance,which is important in dynamic ***,terminal block and randomly functionalized polyisoprene rubbers tethered with di-alanine,tri-alanine and tetra-alanine were *** results showed that the flow activation energy,aggregates ordering and energy dissipation of the hydrogen-bonded aggregates increase with the elongation of oligopeptide length(XA,X=2,3,4),therefore resulting in enhanced mechanical strength and toughness of corresponding ***,the tear strengths are barely affected by oligopeptide lengths in block samples,but promoted from dipeptide to tetrapeptide in random samples,probably due to the well dispersed oligopeptide *** importantly,it is found that the tight binding aggregates of oligopeptides are critical for the excellent fatigue resistance,which is absent in polyisoprene and natural *** loose aggregates dissociate and recombine repeatedly under cyclic loading and the tight aggregates keep the network integrated and ***,the largest hysteresis of PIP-4A-V with the longest oligopeptide length give the lowest heat generation,which is contrary to the traditional sacrificial ***,the oligopeptide aggregates have repeatable energy dissipation properties and cycle life comparable to or even surpassing those of the linked proteins in NR,resulting in similar tensile strength,fracture toughness,and better fatigue resistance relative to *** deep insight on the role of oligopeptide aggregates is very useful for the engineering rubbers served in dynamic environments.

关键词： Polyisoprene Hydrogen bonding oligopeptides Fatigueresistance

Enzyme responsive supramolecular hydrogels assembled from nonionic peptide amphiphiles

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Science China Chemistry 2018年第10期61卷 1314-1319页

作者： Rui Liu Zhekun Shi Jing Sun Zhibo Li Key Laboratory of Biobased Polymer Materials Shandong Provincial Education Department School of Polymer Science and Engineering Qingdao University of Science and Technology

Smart peptide hydrogels are of great interest for their great potential applications. Here, we report a facile approach to prepare a class of enzyme-responsive hydrogels in a scalable manner. These hydrogels self-assemble from a family of nonionic peptide amphiphiles(PAs) synthesized by sequential ring-opening polymerization(ROP) of γ-benzyl-L-glutamate N-carboxyanhydride(BLG-NCA) and L-tyrosine N-carboxyanhydride(Tyr-NCA), followed by subsequent aminolysis. These PA samples can readily form a clear hydrogel with a critical gelation concentration as low as 0.5 wt%. The incorporation of tyrosine residues offers hydrophobicity, hydrogen-bonding interaction and enzyme-responsive properties. The hydrogel-to-nanogel transition is observed under physiological conditions in the presence of horseradish peroxidase(HRP) and hydrogen peroxide(H2 O2). The obtained PA hydrogels are ideal candidates for the new generation of smart scaffolds.

关键词： oligopeptides ring-opening polymerization hydrogel nanogel enzyme responsive

Pd(I)-catalyzed ring-opening arylation of cyclopropyl-α-aminoamides:Access toα-ketoamide peptidomimetics

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Chinese Chemical Letters 2024年第6期35卷 320-326页

作者： Yue Sun Liming Yang Yaohang Cheng Guanghui An Guangming Li School of Chemistry and Materials Science Heilongjiang UniversityHarbin 150080China

We report the unprecedent Pd(I)catalyzed ring-opening arylation of cyclopropyl-α-*** protocol allows facile access to biologically important α-ketoamide-containing oligopeptides and even more challenging peptide-natural product *** selectivity was achieved by introduction of special unnatural amino acids,which also meets the requisite of bioorthogonal *** investigations reveals a distinct domino radical ring-opening process through Pd(I)catalysis.

关键词： Pd(I)catalysis Ring-opening arylation Domino reactions oligopeptides Late-stage functionalization

Mineralization of calcium phosphate controlled by biomimetic selfassembled peptide monolayers via surface electrostatic potentials

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Bioactive Materials 2020年第2期5卷 387-397页

作者： Shuo Wang Yongdong Yang Ronghan Wang Xiangdong Kong Xiumei Wang State Key Laboratory of New Ceramics and Fine Processing Key Laboratory of Advanced Materials of Ministry of EducationSchool of Materials Science and EngineeringTsinghua UniversityBeijing100084China Dongzhimen Hospital Affiliated Beijing University of Chinese Medicine Beijing100700China College of Life Sciences Zhejiang Sci-Tech UniversityHangzhou310018China

The functions of acidic-rich domains in non-collagenous protein during biomineralization are thought to induce nucleation and control the growth of *** tripeptide Asp-Ser-Ser(DSS)repeats are the most common acidic-rich repeated unit in non-collagenous protein of dentin phosphoprotein,the functions of which have aroused extensive *** this study,biomimetic peptides(DSS)n(n=2 or 3)were designed and fabricated into self-assembled monolayers(SAMs)on Au(111)surface as biomimetic organic templates to regulate hydroxyapatite(HAp)mineralization in 1.5 simulated body fluid(1.5 SBF)at 37°*** early mineralization processes and minerals deposited on the SAMs were characterized by X-ray diffraction,scanning electron microscope,and Fourier transform infrared spectroscopy *** SAM-DSS9/DSS9G showed the highest capacity to induce HAp nucleation and growth,followed by SAM-DSS6/DSS6G,SAM-COOH,and *** SAM-(DSS)n had more negative zeta potentials than SAM-COOH surface,indicating that DSS repeats contributed to the biomineralization,which not only provided strong affinity with Ca2+ions through direct electrostatic bonds,but more importantly influence surface electrostatic potentials of the assembled organic template for nucleation.

关键词： Hydroxyapatite Biomineralization Self-assembled monolayer oligopeptides Dentin phosphoprotein

UNIQUE ORAL DRUG DELIVERY SYSTEM

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Chinese Journal of Polymer Science 1995年第4期13卷 315-321页

作者： Raphael M.Ottenbrite Sam Milstein Chemistry Department Virginia Commonwealth UniversityRichmond VA 23284-2006 USAEmisphere Technologies Inc. 15 Skyline Drive Hawthorne NY 10595 USA

An oral drug delivery system using proteinoid microspheres is discussed with respect to itsunique dependence on pH. It has been found that certain drugs such as insulin and heparin canbe encapsulated in proteinoid spheres at stomach pH's (1--3). These spheres also dissemble atintestinal pH's (6--7) releasing the drug for absorption. Using this technique low molecularweight heparin and human growth hormone have been orally delivered successfully to severalanimal species. Future work has been proposed to study the interaction and binding of thespecific drugs with synthesized oligopeptides.

关键词： Oral drug delivery system Proteinoid microspheres oligopeptides

THERMODYNAMIC ANALYSIS OF THE ENANTIOMER RESOLUTION OF TFA-Ala-OMe, TFA-Ala-Ala-OMe, AND TFA-Ala-Ala-Ala-OMe BY GAS CHROMATOGRAPHY ON CHIRASIL-VAL

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Science China Chemistry 1991年第7期34卷 769-776页

作者：林炳承 E.BAYER V.MUSCHALEK B.KOPPENHOEFER Dalian Institute of Chemical Physics Academia SinicaDalian 116012 PRC Instisut

TFA-Ala-OMe, TFA-Ala-Ala-OMe, and TFA-Ala-Ala-Ala-OMe can be separated into 1, 2, and 4 enantiomeric pairs, respectively, by GC on the chiral stationary phase Chirasil-Val. The selectivity of the chiral stationary phase for the different stereoisomers is controlled by both interaction enthalpy and interaction entropy. The interaction enthalpy is approximately proportional to the number of Ala units. Although the whole molecule is involved in the interaction, the C-terminus plays an important role. The elution order of DDD- and LLL-TFA-Ala-Ala-Ala-OMe is opposite to the order of the enhalpy values, and the ratio of net retention data t’r(DDD)/t’r(LLL) is increased with increasing temperature. By lowering the temperature, peak crossing of the enantiomeric pair has been observed. Below the isoselective temperature Tiso’ the order of elution is ruled by the enthalpy of interaction, above Tiso by the entropy of interaction.

关键词： gas chromatography enantiomer resolution oligopeptides Chirasil-Val thermodynamic analysis reversal of peak order.

Oligopeptide Self-Assembly:Mechanisms,Stimuli-Responsiveness,and Biomedical Applications

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CCS Chemistry 2024年第1期6卷 69-90页

作者： Lei Ge Hanyan Xu Xin Jiang Jing Yu School of Materials Science and Engineering Nanyang Technological UniversitySingapore 637553 Institute for Digital Molecular Analytics and Science Nanyang Technological UniversitySingapore 637553

Oligopeptide self-assembly materials have emerged as a promising class of biomaterials with diverse applications in *** review highlights the recent progress in comprehending the selfassembly mechanisms intrinsic to oligopeptides and their behavior in response to specific *** methodically structuring the amino acid sequence and managing external stimuli such as pH levels,redox conditions,or enzymatic activity,we can exercise unprecedented control over the self-assembly *** controlling the self-assembly process of oligopeptides,various structures with extraordinary versatility can be obtained,including micelles,nanofibers,and coacervate droplets,each possessing modifiable mechanical and chemical ***,these self-assembled constructs demonstrate immense potential within varied biomedical *** stimuli-sensitive nature of oligopeptide assembly materials facilitates timely encapsulation and release of therapeutic cargos,consequently eliciting desired cellular *** approach paves the way for more precise tumor targeting,personalized medicinal treatments,and well-regulated drug *** innate biocompatibility and proficiency in replicating the extracellular matrix(ECM)render them ideally suited for applications such as tissue engineering,wound remediation,and regenerative *** summary,oligopeptide self-assembling materials show tremendous potential as adaptable platforms for cutting-edge biomedical applications,thereby bridging the divide between fundamental research and practical clinical application.

关键词： oligopeptides self-assembly nonequilibrium stimuli-responsive behavior biomedical applications

Effect of Cooking Methods on the Chemical Compounds Associated with Umami Taste in Duck Breast Meat

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Journal of Food Science and Engineering 2018年第2期8卷 65-73页

作者： Zhao Shuangjuan Feng Xi Huang Zhicheng Duan Changsheng Tang Jixia Lei Xiaoyu Salam A.Ibrahim Liu Ying Huang Wen College of Food Science and Technology Huazhong Agricultural UniversityWuhan 430070HubeiChina Department of Family and Consumer Sciences North Carolina A&T State UniversityNorth CarolinaGreensboro 27411United States

Dry-curing,wet-curing,stewing and marinating are sequential Chinese traditional meat-processing methods dating back thousands of years ***,little information is available about the contribution of each processing stage to the umami taste in duck breast ***,effects of those meat-processing methods on umami taste related chemical compounds were determined in this ***-curing significantly increased free amino acids,oligopeptides and nucleotides and nucleotides degradation products(Poligopeptides and inosine ***,dry-curing is an important stage in meat processing,not only it produces a pool of taste related compounds,it also stimulates the enzyme activities in the ***,in the stewing stage,the umami taste profile of duck breast meat was gradually *** can conclude that dry-curing and stewing are the two crucial stages to form the umami taste profile in duck breast meat.

关键词： Duck breast meat free amino acids oligopeptides nucleotides inosine monophosphate