- Light-responsive peptide [2]rotaxanes as gatekeepers of mechanised nanocontainers
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Novel mechanized silica nanoparticles incorporating a peptide-based molecular shuttle as a photo-responsive interlocked gatekeeper of nanocontainers are described including the uptake and delivery studies of a model cargo.
- Martinez-Cuezva,Valero-Moya,Alajarin,Berna
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- Propargyl-Substituted Thiocarbamoylbenzamidines of Technetium and Rhenium: Steps towards Bioconjugation with Use of Click Chemistry
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A new propargyl-substituted thiocarbamoylbenzamidine has been synthesized. The compound acts as a tetradentate ligand and forms stable complexes with {ReVO}3+and {TcVO}3+cores. Click couplings of the resulting complexes with benzylazide lead to prototype triazole derivatives, which were analyzed by NMR and IR spectroscopy and mass spectrometry, as well as by X-ray diffraction. A similar coupling procedure has been applied to an azido-modified angiotensin-II peptide, which gives the desired rhenium(V) bioconjugate in good yield. The ease of this coupling and the stability of the conjugate recommend such tetradentate thiocarbamoylbenzamidines also for clinically relevant bioconjugates with99mTc.
- Castillo Gomez, Juan Daniel,Hagenbach, Adelheid,Abram, Ulrich
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- Side-chain glycylglycine-based polymer for simultaneous sensing and removal of copper(II) from aqueous medium
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Since glycylglycine (Gly-Gly) residue in the N-terminal region of human prion protein, a copper binding protein, binds with Cu(II), N-terminus Gly-Gly side-chain containing water soluble block copolymer was synthesized and used for simultaneous sensing an
- Choudhury, Neha,Mete, Sourav,Kambalapalli, Srikanth,De, Priyadarsi
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- Examining ubiquitinated peptide enrichment efficiency through an epitope labeled protein
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Ubiquitination is a dynamic process that is responsible for regulation of cellular responses to stimuli in a number of biological systems. Previous efforts to study this post-translational modification have focused on protein enrichment; however, recent r
- Parker,Oh,Moazami,Pierce,Loziuk,Dean,Muddiman
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- Purification-Free Method for Preparing Technetium-99m-Labeled Multivalent Probes for Enhanced in Vivo Imaging of Saturable Systems
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Metallic radionuclides provide target-specific radiolabeled probes for molecular imaging in radiochemical yields sufficient for administration to subjects without purification. However, unlabeled ligands in the injectate can compete for targeted molecules with radiolabeled probes, which eventually necessitates postlabeling purification. Herein we describe a "1 to 3" design to circumvent the issue by taking advantage of inherent coordination properties of technetium-99m (99mTc). A monovalent RGD ligand possessing an isonitrile as a coordinating moiety (CN-RGD) was reacted with [99mTc(CO)3(OH2)3]+ to prepare [99mTc(CO)3(CN-RGD)3]+ in over 95% radiochemical yields. This complex exhibited higher integrin αvβ3 binding affinity than its unlabeled monovalent ligand, primarily due to its multivalency. This compound visualized a murine tumor without removing unlabeled ligands, while a 99mTc-labeled monovalent probe derived from a monovalent ligand could not. The metal coordination-mediated synthesis of radiolabeled multivalent probes thereby can be a useful approach for preparing ready-to-use target-specific probes labeled with 99mTc and other metallic radionuclides of interest.
- Mizuno, Yuki,Uehara, Tomoya,Hanaoka, Hirofumi,Endo, Yota,Jen, Chun-Wei,Arano, Yasushi
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- Helical Inversion of Peptide-based Supramolecular Co2+ Complexes
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Herein, we report the helical inversion of supramolecular polymeric complexes of Co2+ containing a peptide-based ligand comprising one alanine and three glycine moieties and an achiral terpyridine group. The helicity of the peptide-based supram
- Kim, Ka Young,Kim, Jaehyeong,Park, Hyesong,Choi, Yeonweon,Kwon, Ki-Young,Jung, Jong Hwa
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- Synthesis of Vitamin B12-Antibiotic Conjugates with Greatly Improved Activity against Gram-Negative Bacteria
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There is an urgent need to discover new antibiotics and improve the efficacy of known antibiotics against Gram-negative bacteria. "Trojan horse"conjugates are novel and promising antibiotics. Herein we report the design and synthesis of vitamin-B12-ampicillin conjugates, which exhibited more than 500 times improved activity against Escherichia coli compared with ampicillin itself. Our studies demonstrate that the vitamin-B12 uptake pathway could be employed for effective antibiotic delivery and efficacy enhancement.
- Zhao, Sheng,Wang, Zhi-Peng,Wen, Xumei,Li, Siyu,Wei, Guoxing,Guo, Jian,He, Yun
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- An effective and safe enkephalin analog for antinociception
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Opioids account for 69,000 overdose deaths per annum worldwide and cause serious side effects. Safer analgesics are urgently needed. The endogenous opioid peptide Leu-Enkephalin (Leu-ENK) is ineffective when introduced peripherally due to poor stability a
- Durgarao Viswanadham,B?ttger, Roland,Hohenwarter, Lukas,Nguyen, Anne,Rouhollahi, Elham,Smith, Alexander,Tsai, Yi-Hsuan,Chang, Yuan-Yu,Ortiz, Christopher Llynard,Yang, Lee-Wei,Jimenez, Liliana,Li, Siyuan,Hur, Chan,Li, Shyh-Dar
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- Dynamic Kinetic Cross-Electrophile Arylation of Benzyl Alcohols by Nickel Catalysis
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Catalytic transformation of alcohols via metal-catalyzed cross-coupling reactions is very important, but it typically relies on a multistep procedure. We here report a dynamic kinetic cross-coupling approach for the direct functionalization of alcohols. The feasibility of this strategy is demonstrated by a nickel-catalyzed cross-electrophile arylation reaction of benzyl alcohols with (hetero)aryl electrophiles. The reaction proceeds with a broad substrate scope of both coupling partners. The electron-rich, electron-poor, and ortho-/meta-/para-substituted (hetero)aryl electrophiles (e.g., Ar-OTf, Ar-I, Ar-Br, and inert Ar-Cl) all coupled well. Most of the functionalities, including aldehyde, ketone, amide, ester, nitrile, sulfone, furan, thiophene, benzothiophene, pyridine, quinolone, Ar-SiMe3, Ar-Bpin, and Ar-SnBu3, were tolerated. The dynamic nature of this method enables the direct arylation of benzylic alcohol in the presence of various nucleophilic groups, including nonactivated primary/secondary/tertiary alcohols, phenols, and free indoles. It thus offers a robust alternative to existing methods for the precise construction of diarylmethanes. The synthetic utility of the method was demonstrated by a concise synthesis of biologically active molecules and by its application to peptide modification and conjugation. Preliminary mechanistic studies revealed that the reaction of in situ formed benzyl oxalates with nickel, possibly via a radical process, is an initial step in the reaction with aryl electrophiles.
- Guo, Peng,Wang, Ke,Jin, Wen-Jie,Xie, Hao,Qi, Liangliang,Liu, Xue-Yuan,Shu, Xing-Zhong
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supporting information
p. 513 - 523
(2021/01/12)
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- A photocleavable low molecular weight hydrogel for light-triggered drug delivery
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A photocleavable low-molecular-weight hydrogelator (LMWG) was synthesized based on coumarin derivative. 1H NMR and UV spectroscopy study suggested that the gelator had good gelling ability, and the driving force for the gelation were hydrogen bonding and π-π stacking. This molecular hydrogel exhibited satisfied photocleavage at C-N bond in 7-amino coumarin with the light irradiation (365 nm, 77.5 mW/cm2). The promising photo-triggered drug release of antineoplastics cytarabine hydrochloride has been obtained, due to the photocleavage motived gel-sol transition.
- Liu, Qihong,Wang, Hao,Li, Guotao,Liu, Miaochang,Ding, Jinchang,Huang, Xiaobo,Gao, Wenxia,Huayue, Wu
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supporting information
p. 485 - 488
(2018/06/19)
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- Synthesis of Histidine-Containing Oligopeptides via Histidine-Promoted Peptide Ligation
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Histidine-containing peptides are valuable therapeutic agents for a treatment of neurodegenerative diseases. However, the synthesis of histidine-containing peptides is not trivial due to the potential of imidazole sidechain of histidine to act as a nucleophile if unprotected. A peptide ligation method utilizing the imidazole sidechain of histidine has been developed. The key imidazolate intermediate that acts as an internal acyl transfer catalyst during ligation is generated by deprotonation. Transesterification with amino acids or peptides tethered with C-terminal thioester followed by N→N acyl shifts led to the final ligated products. A range of histidine-containing dipeptides could be synthesized in moderate to good yields via this method without protecting the imidazole sidechain. The protocol was further extended to tripeptide synthesis via a long-range N→N acyl transfer, and tetrapeptide synthesis.
- Huang, Kai-Jin,Huang, Yi-Chen,Lin, Yuya A.
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p. 400 - 403
(2018/02/21)
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- Recyclable hypervalent-iodine-mediated solid-phase peptide synthesis and cyclic peptide synthesis
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The system of the hypervalent iodine(III) reagent FPID and (4-MeOC6H4)3P was successfully applied to solid-phase peptide synthesis and cyclic peptide synthesis. Four peptides with biological activities were synthesized through SPPS and the bioactive cyclic heptapeptide pseudostellarin D was obtained via solution-phase peptide synthesis. It is worth noting that FPID can be readily regenerated after the peptide coupling reaction.
- Liu, Dan,Guo, Ya-Li,Qu, Jin,Zhang, Chi
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p. 1112 - 1119
(2018/06/04)
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- Preparation of dual responsive low-molecular-weight hydrogel for long-lasting drug delivery
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A novel low-molecular-weight hydrogel (LMWG) was fabricated by oligopeptide and phenylboronic acid to obtain a smart molecular hydrogel with dual glucose and pH response for long-term drug delivery in this study. Dual glucose and pH responsiveness of the blank molecular hydrogel was first evaluated by on-line tracking the dynamics curves using UV spectroscopy. Model drugs of phenformin for antidiabetes and doxorubicin for anticancer were selected to evaluate the drug carry and glucose/pH responsive drug release of the molecular hydrogel. The results showed the drug-loaded LMWG had good sustaining and long-lasting drug delivery in physiological or pathological environment.
- Tao, Ning,Li, Guotao,Liu, Miaochang,Gao, Wenxia,Wu, Huayue
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p. 3173 - 3180
(2017/05/08)
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- Tyrosine kinase inhibitor and preparation method and use thereof
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The invention relates to a tyrosine kinase inhibitor and a preparation method and use thereof, and belongs to the technical field of pharmaceutical chemistry. The tyrosine kinase inhibitor having the structural features shown in the general formula I, or its pharmaceutically acceptable salts or stereoisomers can effectively inhibit tyrosine kinase activity, and can inhibit kinases such as DDR1, DDR2, Abl, Src, Btk and Kit. Compared with a positive contrast dasatinib, the tyrosine kinase inhibitor has higher half inhibitory concentration or the same half inhibitory concentration, and especially, aiming at DDR1, DDR2, Src, Btk and Kit, the compound 8j has lower K562 cell half inhibitory concentration. The tyrosine kinase inhibitor has good enzyme inhibitory activity and cell activity and has a large application prospect.
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Paragraph 0222; 0223; 0224
(2017/07/19)
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- Synthesis of Met-enkephalin by solution-phase peptide synthesis methodology utilizing para-toluene sulfonic acid as N-terminal masking of l-methionine amino acid
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The Met-enkephalin, Tyr-Gly-Gly-Phe-Met, was synthesized by the solution-phase synthesis (SPS) methodology employing -OBzl group as carboxyls' protection, while the t-Boc groups were employed for the N-terminal α-amines' protection for the majority of the amino acids of the pentapeptide sequence. The l-methionine (l-Met) amino acid was used as PTSA.Met-OBzl obtained from the simultaneous protection of the α-amino, and carboxyl group with para-toluene sulfonic acid (PTSA) and as-OBzl ester, respectively in a C-terminal start of the 2?+?2?+?1 fragments condensation convergent synthetic approach. The protection strategy provided a short, single-step, simultaneous, orthogonal, nearly quantitative, robust, and stable process to carry through the protected l-methionine and l-phenylalanine coupling without any structural deformities during coupling and workups. The structurally confirmed final pentapeptide product was feasibly obtained in good yields through the current approach.
- Khan, Riaz A.
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p. 884 - 888
(2016/11/11)
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- Penta-glycine copper(II) complexes in slightly alkaline solutions
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The kinetics of the reaction of CuII(GGG), CuII(GGGGG) and CuII(GGGGS), where G = glycine and S = sarcosine, with 4-nitrophenyl-acetate were measured. The results point out that at pH 9.0 hydroxide is an axial, or equatori
- Gaisin, Zeev,Gellerman, Gary,Meyerstein, Dan
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p. 211 - 215
(2016/07/06)
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- Kilogram-Scale Synthesis of Osteogenic Growth Peptide (10-14) Using a Fragment Coupling Approach
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Kilogram-scale synthesis of a bioactive pentapeptide in solution by "3 + 2" fragment coupling strategy has been successively accomplished in the development of OGP (10-14), a minimal OGP-derived sequence that retains the full proliferative activity of the osteogenic growth peptide. The synthetic scheme, coupling conditions, and scaling-up of the process are systematically studied; the epimerization of the tripeptide fragment and pentapeptide are also evaluated.
- Zhang, Teng,Chen, Zhenxing,Tian, Yan,Han, Bin,Zhang, Ning,Song, Wei,Liu, Zhulan,Zhao, Jinli,Liu, Jianli
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supporting information
p. 1257 - 1262
(2015/09/28)
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- Practical Peptide Synthesis Mediated by a Recyclable Hypervalent Iodine Reagent and Tris(4-methoxyphenyl)phosphine
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6-(3,5-Bis(trifluoromethyl)phenyl)-1H,4H-2aλ3-ioda-2,3-dioxacyclopenta[hi]indene-1,4-dione (p-BTFP-iodosodilactone, 1a) was synthesized and demonstrated to be an efficient hypervalent iodine(III) reagent for the synthesis of dipeptides from various standard amino acids, including sterically hindered amino acids, in good to high yields within 30 min in the presence of tris(4-methoxyphenyl)phosphine. In addition, the combined system of 1a/(4-MeOC6H4)3P was used to synthesize the pentapeptide leu-enkephalin in protected form. It is worth noting that 1a can be regenerated readily after reaction.
- Zhang, Chi,Liu, Shan-Shan,Sun, Bo,Tian, Jun
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p. 4106 - 4109
(2015/09/01)
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- RGD-fatty alcohol-modified docetaxel liposomes improve tumor selectivity in vivo
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The tripeptide arginine-glycine-aspartate (RGD) was conjugated with various fatty alcohols to obtain RGDOCnH2n + 1 (n = 8, 10, 12, 14, 16, 18), which were incorporated into the bilayer of docetaxel liposomes to improve their tumor sp
- Li, Yinghuan,Zheng, Xuelian,Sun, Yi,Ren, Zhao,Li, Xuemei,Cui, Guohui
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p. 133 - 141
(2014/05/20)
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- Α-BORYL ISOCYANIDES, BOROPEPTIDES AND BORON HETEROCYCLES
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This application pertains to α-boryl isocyanates, wherein the boronate moiety is in the form of an N-methyliminodiacetic acid (MIDA) boronate of the Formula (2) and the utility of said compounds in the synthesis of the borylamide motif (Β-C-Namide) in the scaffold of biologically-active boropeptides, such as bortezomib, in the enablement of heterocycle synthesis, and in multi-component reactions (MCRs), such as the Ugi and Passerini processes.
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Page/Page column 23
(2014/10/18)
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- A bis(phosphine)-modified peptide ligand for stable and luminescent quantum dots in aqueous media
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We describe a new class of ligands for semiconductor nanoparticles (quantum dots = QDs), which bind well and allow for their facile dissolution in aqueous solution. As a proof of principle, we have designed and synthesized a novel bis(phosphine)-modified
- Jung, Michael E.,Trzoss, Michael,Tsay, James M.,Weiss, Shimon
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p. 2426 - 2430
(2013/09/23)
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- α-boryl isocyanides enable facile preparation of bioactive boropeptides
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Entry to bioactive boropeptides: MIDA-containing α-boryl isocyanides are isolable molecules which allow one-step access to boroalkyl-functionalized heterocycles as well as biologically active boropeptides through a multicomponent approach. Among these derivatives are 6-boromorpholinones, novel borocycles with nanomolar IC50 values for 20S proteasome inhibition. MIDA=N-methyliminodiacetyl. Copyright
- Zajdlik, Adam,Wang, Zezhou,Hickey, Jennifer L.,Aman, Ahmed,Schimmer, Aaron D.,Yudin, Andrei K.
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supporting information
p. 8411 - 8415
(2013/09/02)
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- Design, synthesis, insecticidal evaluation and molecular docking studies of cis-nitenpyram analogues bearing diglycine esters
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Based on the strategies of receptor structure-guided neonicotinoid design, a series of novel cis-nitenpyram analogues bearing diglycine esters were designed and synthesized. Preliminary bioassays indicated that the insecticidal spectra of the target compounds were expanded compared with our previous work, while all the target compounds presented excellent insecticidal activities against Nilaparvata lugens and Aphis medicagini at 100 mg/L. Among these analogues, 6b showed 100% mortality against Nilaparvata lugens (LC50 = 0.163 mg/L) and 90% against Aphis medicagini at 4 mg/L. SARs suggested that the insecticidal potency of our designed cis-nitenpyram analogues was dual-controlled by the size and species of the ester groups. The molecular docking simulations revealed that the structural uniqueness of these analogues may lead to a unique molecular recognition and binding mode compared with the previously designed compounds. Introduction of the peptide bond gave rise to more significant hydrogen bonds between the nitenpyram analogues bonding with the amino acid residues of insect nAChRs. The docking results explained the SARs observed in vitro, and shed light on the novel insecticidal mechanism of these cis-nitenpyram analogues.
- Chen, Yanxia,Sun, Chuanwen,Wen, Xiaxia,Zhang, Wanggeng
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p. 159 - 168
(2013/07/26)
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- PEG prodrug of gambogic acid: Amino acid and dipeptide spacer effects
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The clinical application of gambogic acid (GA), a natural component with promising antitumor activity, was limited due to its extremely poor aqueous solubility, rapid elimination in vivo, and wide biodistribution. To solve these problems, 30 poly(ethylene
- Ding, Ya,Zhang, Peng,Tang, Xiao-Yan,Zhang, Can,Ding, Song,Ye, Hai,Ding, Qi-Long,Shen, Wen-Bin,Ping, Qi-Neng
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p. 1694 - 1702
(2012/08/08)
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- Guanidine hydrochloride as an organocatalyst for N-Boc protection of amino groups
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A simple and efficient method for the chemoselective N-Boc protection of the amine moiety in a variety of compounds is described using di-tert-butyl dicarbonate and guanidine hydrochloride as an organocatalyst in ethanol at 35-40°C. Selective mono-N-Boc protection of diamines and chemoselective protection of hydroxylamines without formation of any side products is achieved. Amino acids and peptides are N-Boc protected efficiently in excellent yields under convenient reaction conditions.
- Jahani, Fatemeh,Tajbakhsh, Mahmood,Golchoubian, Hamid,Khaksar, Samad
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supporting information; experimental part
p. 1260 - 1264
(2011/04/15)
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- Novel tetrapeptide, RGDF, mediated tumor specific liposomal doxorubicin (DOX) preparations
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Arginine-glycine-aspartate (RGD) has been shown to possess a strong affinity for the integrins overexpressed in tumor cells, especially during tumor invasion, angiogenesis and metasis. Based on work from others, a novel tetrapeptide, arginine-glycine-aspa
- Du, Huirui,Cui, Chunying,Wang, Lili,Liu, Hu,Cui, Guohui
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experimental part
p. 1224 - 1232
(2012/05/04)
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- Design, synthesis and inhibition activity of novel cyclic peptides against protein tyrosine phosphatase A from Mycobacterium tuberculosis
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Mycobacterium tuberculosis, the causative agent for tuberculosis has employed several signalling molecules to sense the host cellular environment and act accordingly. For example, protein tyrosine phosphatase A (MPtpA) of M. tuberculosis, a signalling pro
- Chandra, Koushik,Dutta, Debajyoti,Das, Amit K.,Basak, Amit
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supporting information; scheme or table
p. 8365 - 8373
(2011/02/25)
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- Synthesis of chimeric tetrapeptide-linked cholic acid derivatives: Impending synergistic agents
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Tetrapeptides derived from glycine and β-alanine were hooked at the C-3β position of the modified cholic acid to realize novel linear tetrapeptide-linked cholic acid derivatives. All the synthesized compounds were tested against a wide variety of microorganisms (Gram-negative bacteria, Gram-positive bacteria and fungi) and their cytotoxicity was evaluated against human embryonic kidney (HEK293) and human mammary adenocarcinoma (MCF-7) cell lines. While relatively inactive by themselves, these compounds interact synergistically with antibiotics such as fluconazole and erythromycin to inhibit growth of fungi and bacteria, respectively, at 1-24 μg/mL. The synergistic effect shown by our novel compounds is due to their inherent amphiphilicity. The fractional inhibitory concentrations reported are comparable to those reported for Polymyxin B derivatives.
- Bavikar, Sudhir N.,Salunke, Deepak B.,Hazra, Braja G.,Pore, Vandana S.,Dodd, Robert H.,Thierry, Josiane,Shirazi, Fazal,Deshpande, Mukund V.,Kadreppa, Sreenath,Chattopadhyay, Samit
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supporting information; experimental part
p. 5512 - 5517
(2009/06/18)
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- Synthetic receptors for the differentiation of phosphorylated peptides with nanomolar affinities
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Artificial ditopic receptors for the differentiation of phosphorylated peptides varying in i + 3 amino acid side chains were synthesized, and their binding affinities and selectivities were determined. The synthetic receptors show the highest binding affi
- Grauer, Andreas,Riechers, Alexander,Ritter, Stefan,Koenig, Burkhard
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supporting information; experimental part
p. 8922 - 8927
(2009/09/25)
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- Ring-opening Cross-metathesis (ROCM) as a novel tool for the ligation of peptides
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The development of ring-opening cross-metathesis (ROCM) as a novel tool for the site-specific ligation of peptide units is reported. The resulting structural units at the site of ligation resulting from ROCM resemble proline as well as other known ss-turn
- Michaelis, Simon,Blechert, Siegfried
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p. 2358 - 2368
(2008/02/04)
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- Internally quenched peptides for the study of lysostaphin: An antimicrobial protease that kills Staphylococcus aureus
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Lysostaphin (EC. 3.4.24.75) is a protein secreted by Staphylococcus simulans biovar staphylolyticus and has been shown to be active against methicillin resistant S. aureus (MRSA). The design and synthesis of three internally quenched substrates for lysost
- Warfield, Rachel,Bardelang, Philip,Saunders, Helen,Chan, Weng C.,Penfold, Christopher,James, Richard,Thomas, Neil R.
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p. 3626 - 3638
(2008/10/09)
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- Synthesis, characterization and biological evaluation of cyclic peptides: Viscumamide, yunnanin A and evolidine
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Three biologically active cyclic peptides, viscumamide, yunnanin A and evolidine were synthesized and the structures were established on the basis of analytical, IR, NMR and mass spectral data. These newly synthesized cyclic peptides were evaluated for an
- Poojary, Boja,Belagali
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p. 1313 - 1320
(2008/02/08)
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- Synthesis and biological evaluation of Pseudostellarin D
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Pseudostellarin D, a natural cyclic heptapeptide, was successfully synthesized and characterized by IR, 1H NMR, 13C NMR, FABMS and elemental analysis. The synthesized compound was evaluated for antibacterial, antifungal, anti-inflammatory and anthelmintic activities.
- Himaja,Harish Kumar,Ramana,Belagali
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p. 525 - 529
(2007/10/03)
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- Synthesis of the palmitoylated and prenylated C-terminal lipopeptides of the human R- and N-Ras proteins
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For the study of biological phenomena influenced by the R- and N-Ras proteins, characteristic peptides which embody the correct lipid modifications of their parent proteins (palmitoyl thioesters, geranylgeranyl thioethers, and farnesyl thioethers), as well as analogues thereof, may serve as efficient tools. For the construction of such acid- and base labile peptide conjugates the allyl ester was developed as C-terminal protecting group. Allyl esters are cleaved selectively and in high yields from lipidated peptides by Pd(0)-mediated allyl transfer to accepting N- or C-nucleophiles like morpholine and N,N'-dimethylbarbituric acid. This protecting group technique formed the key step in the synthesis of the characteristic S-palmitoylated and S-isoprenylated C-terminus of human R-Ras and human N-Ras proteins, as well as several analogues thereof. Deprotections are so mild that no undesired side reactions of the lipid conjugates are observed. Copyright (C) 1999 Elsevier Science Ltd.
- Schmittberger,Waldmann
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p. 749 - 762
(2007/10/03)
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- Synthesis and properties of N(α)-(tert-butyloxycarbonyl)peptide p- guanidinophenyl esters as trypsin substrates
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N(α)-(tert-Butyloxycarbonyl)peptide p-guanidinophenyl esters were synthesized by amidination of N(α)-(tert-butyloxycarbonyl)peptide p- aminophenyl esters with 1-[N,N'-bis(benzyloxycarbonyl)amidino]pyrazole, followed by deprotection by catalytic hydrogenation, in good total yields. These synthetic esters were characterized as specific substrates for trypsin, and kinetic parameters for the trypsin-catalyzed hydrolysis are presented.
- Itoh,Sekizaki,Toyota,Tanizawa
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p. 2082 - 2087
(2007/10/03)
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- Elastomeric polypeptides as vascular prosthetic materials
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A vascular prosthetic material having at least one layer containing an elastomeric material capable of reversibly contracting and relaxing by an inverse temperature transition. The vascular prosthetic material matches the compliance and elasticity of vessels replaced, and is biocompatible and biodegradable. The material may also have incorporated therein chemotactic peptides and cell attachment sequences.
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- Bioelastomeric materials suitable for the protection of burn areas or the protection of wound repair sites from the occurrence of adhesions
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An elastomeric material, capable of reversibly contracting and relaxing by an inverse temperature transition, in a form suitable for use as a protective layer between a mammalian repair site and a second tissue site whereby adhesion involving said repair site and said second tissue site is substantially prevented.
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- Polynonapeptide bioelastomers having an increased elastic modulus
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A polynonapeptide of the formula: wherein: α is a peptide-forming residue of L-Valine or another peptide-forming residue capable of functioning in position i of a β-turn in a polypeptide; β is a peptide-forming residue of L-Proline or another peptide-forming residue capable of functioning in position i+1 of a β-turn in a polypeptide; γ is a peptide-forming residue of L-Glycine or another peptide-forming residue capable of functioning in position i+2 of a β-turn in a polypeptide; δ is a peptide-forming residue of L-Phenylalanine or another peptide-forming residue capable of functioning in position i+3 of a β-turn in a polypeptide; ε is a peptide-forming residue of Glycine, or D-Alanine, when functioning as position i' of a subsequent β-turn in a polypeptide when δ is as defined, or ε is as defined for α when δ is Glycine or D-Alanine; θ is a peptide-forming residue of L-Valine, L-Alanine or another peptide-forming residue as defined above for α, or when functioning as position (i+1)' of a subsequent β-turn in a polypeptide, θ is a peptide-forming residue as defined above for β; λ is a peptide-forming residue of Glycine, D-Alanine or another peptide-forming residue as defined for γ, when functioning as position (i+2)' of a subsequent β-turn in a polypeptide; ? is a peptide-forming residue of L-Alanine or another peptide-forming residue as defined for δ, when functioning as position (i+3)' in a subsequent β-turn in a polypeptide, or a direct bond; and ρ is a peptide-forming residue of Glycine, or D-Alanine; wherein X is βγδεθλ?ρ, γδεθλ?ρ, γεθλ?ρ, εθλ?ρ, θλ?ρ, λ?ρ, ?ρ, ? or a direct bond; Y is αβγδεθλ?, αβγδεθλ, αβγδεθ, αβγδε, αβγδ, αβγ, αβ, α or a direct bond; and n has a value of 1 to about 5,000, and with the proviso that no more than three or residues ε, θ, λ, ? and ρ are simultaneously a peptide-forming residue of Glycine. The polynonapeptides have increased elastic moduli and exhibit chemotaxis toward fibroblasts and endothelial cells.
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- USE OF 4-CHLOROBUTYL ESTERS IN PEPTIDE SYNTHESIS
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Ho and Wong synthesised 4-chlorobutyl esters of simple carboxylic acids and removed the ester group by the action of sodium sulfide under reflux conditions.We describe here the synthesis of the 4-chlorobutyl esters of glycine and L-phenylalanine and its use in the synthesis of six new N-protected dipeptides 4-chlorobutyl esters (XHNCH2CO-HNCHRCO2(CH2)4Cl; R = H, CH2Ph; X = Z, Boc, Trt).The selective removal of the 4-chlorobutyl group can be achieved by the action of the sulfide anion in aqueous acetonitrile (room temperature, 1.5 to 5 h).The conditions are milder than those described, but similar to the conditions used with the dipeptides 2-bromoethyl esters.The N-protected dipeptides were isolated in 50 to 80percent yield.
- Trigo, M. Joaquina S. A. Amaral,Santos, M. Isabel A. Oliveira
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p. 2357 - 2359
(2007/10/02)
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- NEW APPROACH TO THE USE OF 2-BROMOETHYL ESTERS IN PEPTIDE SYNTHESIS
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The synthesis of six fully protected dipeptides 2-bromoethyl esters and a new method for the removal of the C-protection by the action of the sulphide anion, at room temperature, are described.
- Amaral Trigo, M. Joaquina S. A.,Oliveira Santos, M. Isabel A.
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p. 2787 - 2790
(2007/10/02)
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- Temperature correlated force and structure development of elastin polytetrapeptides and polypentapeptides
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A bioelastomer containing elastomeric units comprising tetrapeptide, or pentapeptide or units thereof modified by hexapeptide repeating units and mixtures thereof, wherein said repeating units comprise amino acid residues selected from the group consisting of hydrophobic amino acid and glycine residues, wherein said repeating units exist in a conformation having a β-turn which comprises a polypentapeptide unit of the formula: wherein I is a peptide-forming residue of L-isoleucine; P is a peptide-forming residue of L-proline; G is a peptide-forming residue of glycine; V is a peptide-forming residue of L-valine; and wherein X1 is PGVG, GVG, VG, G or a covalent bond; Y1 is IPGV, IPG, IP, I or a covalent bond; and n is an integer from 1 to 200, or n is 0, with the proviso that X1 and Y1 together constitute at least one of said pentameric unit, in an amount sufficient to adjust the development of elastomeric force of the bioelastomer to a predetermined temperature.
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- Conformations in the Solid State and Solubility Properties of Protected Homooligopeptides of Glycine and β-Alanine
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IR spectroscopic conformational analyses of Boc-Glyn-OBzl (n=3-7) and Boc-(β-Ala)n-OBzl (n=3-8) were performed in the solid state, suggesting the occurrence of the β-sheet structure in the higher oligomers (n=5-8).Solubility data ind
- Narita, Mitsuaki,Doi, Masamitsu,Kudo, Koji,Terauchi, Yusuke
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p. 3553 - 3558
(2007/10/02)
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- Design of the Synthetic Route for Peptides and Proteins Based on the Solubility Prediction Method. I. Synthesis and Solubility Properties of Human Proinsulin C-Peptide Fragments
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The usefulness of the solubility prediction method is demonstrated using relatively small peptide fragments of human proinsulin C-peptide.The propriety of the solubility prediction method for peptides having polar side chains is also examined in the following respects: (1) Peptide intermediates smaller than a heptapeptide have high solubility regardless of their c> values; (2) the c> values of peptide intermediates are useful for judging solubility of peptide intermediates equal to or larger than an octapeptide level; (3) the Pro residue in a central position of a peptide chain is effective for increasing peptide solubility; and (4) there is critical chain length for peptide insolubility caused by a β-sheet aggregation.A strategy suitable for the design of the synthetic route or human proinsulin C-peptide is subsequently discussed on the basis of the solubility prediction of peptide intermediates.
- Narita Mitsuaki,Ogura, Toshihiko,Sato, Kazuhiro,Honda, Shinya
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p. 2433 - 2438
(2007/10/02)
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- The L-Proline Residue as a 'Break-point' in Metal - Peptide Systems
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Results are reported of a potentiometric and spectrophotometric study of the H+ and Cu2+ complexes of the tetrapeptides X-Gly-Gly-Gly, Gly-X-Gly-Gly, Gly-Gly-X-Gly, and Gly-Gly-Gly-X where X is the proline (Pro) and sarcosine (Sar) residue (Gly=glycine).All the tetrapeptides (HL) form the series of complexes , -1L>, -2L>, and -3L> (charges omitted).The ligands Gly-X-Gly-Gly also form the bis-complex, .When inserted in a peptide chain the Pro and Sar residues cannot co-ordinate to Cu2+ through their peptide nitrogens since they do not possess ionizable protons.In addition the Pro residue tends to force the peptide chain to form a 'β-turn' and so adopt a 'bent' conformation.These studies demonstrate the formation of a large chelate ring when tetrapeptides containing Pro (and , to a smaller extent, Sar) in the second or third positions co-ordinate to Cu2+.This ring spans the terminal residues of the peptide chain and locks the peptide into a 'bent' or 'horse-shoe' shaped conformation.Cu2+ could therefore play an important role in activating oligopeptides (e.g. neuropeptides) containing proline.
- Pettit, Leslie D.,Steel, Ian,Formicka-Kozlowska, Grazyna,Tatarowski, Tomasz,Bataille, Michael
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p. 535 - 540
(2007/10/02)
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- STUDIES OF BITTER PEPTIDES FROM CASEIN HYDROLYZATE - III. BITTER TASTE OF SYNTHETIC ANALOGS OF BPIa ARG-GLY-PRO-PRO-PHE-ILE-VAL) CONTAINING D-PROLINE OR GLYCINE IN PLACE OF L-PROLINE.
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In order to elucidate the relationship between chemical structure and bitter taste of BPIa, the analogs containing D-proline or glycine in place of the L-proline in the 3- or 4-positions were synthesized. The bitter taste of left bracket D-Pro**3**,**4 ri
- Miyake,Kouge,Kanehisa,Okai
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p. 1678 - 1681
(2007/10/02)
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- Dehydro-enkephalins. Part 7. A Potent Dehydroleucine-enkephalin Resistant to Carboxypeptidase
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To preserve the enkephalin-like properties together with resistance to enzymatic degradation, we have synthesized unsaturated analogues of leucine enkephalin, containing dehydroleucine (ΔLeu5) in the Z-configuration (isopropyl and C=O, trans) a
- Shimohiagashi, Yasuyuki,Stammer, Charles H.
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p. 803 - 808
(2007/10/02)
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- Novel Analogues of Enkephalin: Identification of Functional Groups Required for Biological Activity
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Novel tri- and tetrapeptide analogues of enkephalin, in conjunction with earlier structure-activity data, confirm that chemical substituents present in the first and fourth residues of enkephalin are required for in vitro biological activity.A class of ar
- Gorin, Fredric A.,Balasubramanian, T. M.,Cicero, Theodore J.,Schwietzer, John,Marshall, Garland R.
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p. 1113 - 1122
(2007/10/02)
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- 1-Peptidyl derivatives of di-O-aminoglycosyl-1,3-diaminocyclitol antibacterial agents
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Disclosed herein are di-O-(aminoglycosyl)-1,3-diaminocyclitol antibacterial agents having on the 1-N-position of the 1,3-diaminocyclitol moiety a dipeptidyl or a tripeptidyl substituent. The compounds are useful antibacterial agents, as are their non-toxic pharmaceutically acceptable acid addition salts. Also disclosed are methods for preparing such agents from di-O-(aminoglycosyl)-1,3-diaminocyclitol antibacterial agents which are unsubstituted at the 1-N-position.
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- Process for producing triglycyl-lysine vasopressin and intermediates therefor
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A new process for preparing the cyclic dodecapeptide triglycyl-lysine vasopressin of the formula STR1 which comprises the preparation of a first hexapeptide of formula Boc--Gly--Gly--Gly--Cys(Trt)--Tyr--Phe--NHNH2 and a second hexapeptide of formula H--Gln(Mbh)--Asn(Mbh)--Cys(Trt)--Pro--Lys(Boc)--Gly--NH2 by a series of condensations involving the reaction of an appropriately protected peptide unit having an activated carboxyl with an appropriately protected peptide having a free amino group. Subsequently, the first and second hexapeptides are condensed according to the azide coupling method to obtain the linear protected dodecapeptide of formula Boc--Gly--Gly--Gly--Cys(Trt)--Tyr--Phe--Gln(Mbh)--Asn(Mbh)--Cys(Trt)--Pro--Lys(Boc)--Gly--NH2 ; thereafter the linear protected dodecapeptide is transformed into the desired cyclic dodecapeptide, triglycyllysine vasopressin, by oxidizing and deprotecting processes.
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