- A useful method for the preparation of fully protected peptide acids and esters
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Resin bound peptides can be cleaved from the Kaiser oxime resin using various oxygen nucleophiles (H2O, CH3OH, PhCH2OH) with DBU. Fully protected peptide acids and esters are obtained rapidly and with good yields using this new method of cleavage.
- Pichette, Andre,Voyer, Normand,Larouche, Remi,Meillon, Jean-Christophe
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- Polyethylene glycol coupling medicine as well as preparation method and application thereof
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The invention relates to the technical field of medicines, relates to a polyethylene glycol coupled drug as well as a preparation method and an application thereof, and in particular relates to a polyethylene glycol coupled drug as shown in a formula I or pharmaceutically acceptable salt thereof. The invention also relates to a preparation method of the polyethylene glycol coupled drug or the pharmaceutically acceptable salt thereof, a pharmaceutical composition containing the polyethylene glycol coupled drug or the pharmaceutically acceptable salt thereof, and the application of the polyethylene glycol coupled drug or the pharmaceutically acceptable salt thereof in preparation of drugs.
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Paragraph 0351-0354
(2021/05/29)
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- Synthesis and preliminary evaluation of novel bone-targeting NSAIDs prodrugs based on glutamic acid oligopeptides
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Osteoarthritis is no doubt a difficult disease to manage. Targeted delivery of drugs to bone may not only enhance the treatment efficacy, but also reduces the quantity of drug administered. In this paper, we have synthesized two series of NSAID-Glu oligop
- Zhao, Yi,He, Dongsheng,Ma, Lifang,Guo, Li
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p. 585 - 590
(2016/03/22)
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- CONJUGATES OF WATER SOLUBLE POLYMER-AMINO ACID OLIGOPEPTIDE-DRUG, PREPARATION METHOD AND USE THEREOF
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A conjugate of water soluble polymer-amino acid oligopeptide-drug of Formula (I) below and a pharmaceutical composition comprising the conjugate are provided. In the conjugate, P is a water soluble polymer; X is a linking group, wherein the linking group links P and A1; each of A1, A2 and A3 is independently same or different amino acid residue or amino acid analogue residue; each of D1 and D2 is independently same or different drug molecule residue; a is 0 or 1; b is an integer of 2-12; c is an integer of 0-7; d is 0 or 1. The conjugate could improve drug load capacity, water solubility, stability and activity of the drug.
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- Role of basic and acidic fragments in delicious peptides (Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala) and the taste behavior of sodium and potassium salts in acidic oligopeptides.
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The role of the acidic fragment (Asp-Glu-Glu) in delicious peptides was investigated in detail by using the Na+ or K+ salts of acidic oligopeptides so that amount of Na+ or K+ intake of peptides composed of acidic amino acids could be varied by changing their sequences. The taste of these peptides was confirmed to vary with Na+ or K+ intake. Additionally, in order to study the role of basic (Lys-Gly) and acidic (Asp-Glu-Glu) fragments in delicious peptides for producing the taste, five delicious peptide analogs, Ser-Leu-Ala-Lys-Gly-Asp-Glu-Glu, Ser-Leu-Ala-Asp-Glu-Glu-Lys-Gly, Lys-Gly-Ser-Leu-Ala-Asp-Glu-Glu, Lys-Gly-Asp-Glu-Glu, and Glu-Glu-Asp-Gly-Lys, were synthesized. The intensity of the umami and/or salty taste of these peptides and their Na salts was almost the same, despite their chemical structures being different. These results indicate that the acidic fragment as well as the basic fragment plays an important role in the taste production and intensity of delicious peptides, and that an umami or salty taste can be produced by the localization of the cation of the basic fragment and the anion of the acidic fragment.
- Nakata,Takahashi,Nakatani,Kuramitsu,Tamura,Okai
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p. 689 - 693
(2007/10/02)
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- The β-Type Structures of Very Simple N-Octanoyl-L-glutamic Acid Oligomers (Residue Number, N = 2 - 6) and Their β1 -> β2 - Type Transition
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N-Octanoyl-L-glutamic acid oligomers (residue number, N = 2 - 6) have been synthesized in order to study their molecular conformations in the solid state.The X-ray powder diffraction patterns and vibrational spectra of these oligomers have been investigat
- Uehara, Toshiyuki,Okabayashi, Hirofumi,Taga, Keijiro,Yoshida, Tadayoshi,Kojima, Hiroshi,Nishio, Etuso
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p. 2196 - 2203
(2007/10/02)
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- Synthesis of acyclic and dehydroaspartic acid analogues of Ac-Asp-Glu-OH and their inhibition of rat brain N-acetylated α-linked acidic dipeptidase (NAALA dipeptidase)
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The following structural and conformationally constrained analogues of Ac-Asp-Glu-OH (1) were synthesized: Ac-Glu-Glu-OH (2), Ac-D-Asp-Glu-OH (3), Ac-Glu-Asp-OH (4), Ac-Asp-Asp-OH (5), Ac-Asp-3-aminohexanedioic acid (6), Ac-3-amino-3-(carboxymethyl)propanoyl-Glu-OH (7), N-succinyl-Glu-OH (8), N-maleyl-Glu-OH (9), N-fumaryl-Glu-OH (10), and Ac-Δ(z)Asp-Glu-OH (11). These analogues were evaluated for their ability to inhibit the hydrolysis of Ac-Asp-[3,4-3H]-Glu-OH by N-acetylated α-linked acidic dipeptidase (NAALA dipeptidase) in order to gain some insight into the structural requirements for the inhibition of this enzyme. Analogues 4-6 and 9 were very weak inhibitors of NAALA dipeptidase (K(i) > 40 μM), while 2, 3, and 7 with K(i) values ranging from 3.2-8.5 μM showed intermediate inhibitory activity. The most active inhibitors of NAALA dipeptidase were compounds 8, 10, and 11 with K(i) values of 0.9, 0.4, and 1.4 μM, respectively. These results suggest that the relative spacing between the side chain carboxyl and the α-carboxyl group of the C-terminal residue may be important for binding to the active site of the enzyme. They also indicate that the χ1 torsional angle for the aspartyl residue is in the vicinity of 0°.
- Subasinghe,Schulte,Chan,Roon,Koerner,Johnson
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p. 2734 - 2744
(2007/10/02)
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- Photoinduced Electron Transfer on a Single α-Helical Polypeptide Chain
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Electron transfer on an α-helical polypeptide carrying the sequence L-p-(dimethylamino)phenylalanine (dmaPhe)-L-alanine-L-1-pyrenylalanine (pyrAla) at the midpoint of an α-helical poly(γ-benzyl L-glutamate) chain was studied.Conformational energy calculation for the side-chain orientations predicted that only one type of orientation is allowed for both the dmaPhe and the pyrAla units.The center-to-center (edge-to-edge) distance between the two chromophores was estimated to be 13.2 (9.4) Angstroem.The fluorescence spectrum showed no exciplex emission in thepolypeptide, in contrast to the strong exciplex observed for a model tripeptide having the same dmaPhe-Ala-pyrAla sequence.The rate of electron transfer was calculated from the decay times of pyrenyl fluorescence of the polypeptide in trimethyl phosphate and in tetrahydrofuran solutions.The ket was on the order of 1E5 (s-1).The activation enthalpy was 1.4 kcal mol-1 in trimethyl phosphate and smaller than 1 kcal mol-1 in less polar solvents near room temperature.It was even smaller at lower temperatures.The activation entropy was less than -25 eu, suggesting a nonadiabatic electron transfer.In contrast to the slow electron transfer in the polypeptide, the rate constant for the model tripeptide was on the order of 1E7-1E8 (s-1) around room temperature, and the activation enthalpy was higher than that in the polypeptide case.
- Sisido, Masahiko,Tanaka, Ryo,Inai, Yoshihito,Imanishi, Yukio
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p. 6790 - 6796
(2007/10/02)
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- Variation in Bitterness Potency When Introducing Gly-Gly Residue into Bitter Peptides
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We previously reported that Gly-Gly-Arg-Pro and Arg-Pro-Gly-Gly, the derivatives of a bitter peptide Arg-Pro, had no bitterness although Gly-Arg-Pro and Arg-Pro-Gly had a bitter taste at the same level as that of Arg-Pro.To elucidate the mechanism of elimination of bitterness by the introduction of the Gly-Gly residues, we synthesized Gly-Gly derivatives of other bitter peptides such as Phe-Phe, Val-Val-Val, Arg-Pro-Phe-Phe, and examined the effectiveness of Gly-Gly residues in eliminating bitterness.We suggest that, for Arg-Pro and Val-Val-Val, the Gly-Gly residue might prevent a hydrophobic group from binding to a taste receptor.
- Shinoda, Ichizo,Nosho, Yasuharu,Kouge, Katsushige,Ishibashi, Norio,Okai, Hideo,et al.
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p. 2103 - 2110
(2007/10/02)
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