- Highly Productive Continuous Flow Synthesis of Di- and Tripeptides in Water
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The reaction of amino acid derived N-carboxyanhydrides (NCAs) with unprotected amino acids under carefully controlled aqueous continuous flow conditions realized the formation of a range of di- and tripeptide products in 60-85% conversion at productivities of up to 535 g·L-1h-1. This required a fundamental understanding of the physicochemical aspects of the reaction resulting in the design of a custom-made continuous stirred tank reactor (CSTR) with continuous solids addition, high shear mixing, automated pH control to avoid the use of buffer, and efficient heat removal to control the reaction at 1 ± 1 °C.
- Jolley, Katherine E.,Nye, William,González Ni?o, Carlos,Kapur, Nikil,Rabion, Alain,Rossen, Kai,Blacker, A. John
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p. 1557 - 1565
(2017/10/25)
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- DPP4 INHIBITOR AND PHARMACEUTICAL APPLICATION THEREOF
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The present invention provides a Dpp4 inhibitor which comprises a leucine derivative of the following formula (1) or a methionine derivative of the following formula (2): wherein each R1 and R3 represents a hydrogen atom (H) and an L-amino acid residue; R2 represents a hydroxyl group (OH), alkoxy group having 1 to 6 carbon atoms, amino group (NH2), alkylamino group having 1 to 6 carbon atoms, glycine residue, β-alanine residue, L-amino acid (except for proline, alanine and phenylalanine) residue or L-amino-acid amide (except for proline amide, alanine amide and phenylalanine amide) residue; and R4 represents a hydroxyl group (OH), alkoxy group having 1 to 6 carbon atoms, amino group (NH2), alkylamino group having 1 to 6 carbon atoms, glycine residue, β-alanine residue, L-amino acid (except for proline and alanine) residue or L-amino-acid amide (except for proline amide and alanine amide) residue. These derivatives also act as autophagy regulators.
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Page/Page column 8-9
(2008/06/13)
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- DIPEPTIDE-CONTAINING COMPOSITION FOR ORAL ADMINISTRATION
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The present invention provides a composition for oral administration, which comprises at least one kind of dipeptide represented by the formula: ????????X-Y (wherein X represents alanyl, glycyl, arginyl, seryl, α-aspartyl or α-glutamyl, and Y represents valine, leucine or isoleucine), with an object of providing a composition for oral administration which is excellent in nutrition, pharmacological effect and gustation and comprises at least one kind selected from valine, leucine and isoleucine, or providing a composition for oral administration which is excellent in processing characteristics such as solubility and tableting property and comprises at least one kind selected from valine, leucine and isoleucine.
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Page/Page column 6
(2008/12/06)
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- Compounds which modify serotoninergic transmission, diagnostic and therapeutic applications
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Compounds having the following peptide sequence: X Leu Y, wherein X is H or Ala or Leu-Ser-Ala, Y is OH or peptide sequence having from 1 to 10 amino acids, with the terminal carboxy end being amidified by a NH2group, or esterified by a substituted or non-substituted hydrocarbyloxy, with the proviso that X and Y are not simultaneously H and OH, respectively, The invention also concerns the corresponding compounds wherein the peptide binding group —CO—NH— is replaced by a binding group resisting protease enzymatic degradation, or wherein the peptide backbone comprises one or more intercalated groups making the peptide binding resistant to enzymatic degradation. Also described are compounds comprising a grouping whose spatial structure is substantially identical to that of a peptide of the sequence X-Leu-Y wherein X and Y have the above-mentioned definition.
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- Rates of reduction of N-chlorinated peptides by sulfite: Relevance to incomplete dechlorination of wastewaters
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Biologically induced fragmentation of proteins during wastewater treatment produces peptides, which form long-lasting organic chloramines when the water is disinfected with Cl2. To protect aquatic wildlife from residual chlorine, including chloramines, wastewaters are often treated with sulfur dioxide or sulfite salts. This strategy incompletely eliminates residual chlorine species. Here we report that dechlorination rate constants of N- chloropeptides are 1-2 orders of magnitude smaller than those for NH2Cl and some aliphatic organic chloramines. Slow rates explain the prevalence of N- chloropeptides in dechlorinated wastewaters after faster reacting chlorine species have been eliminated. Dechlorination is subject to general acid catalysis. For N-chlorinated leucylalanine, the rate law above pH 6 in phosphate buffer at 25 °C and / ? 0.1 M is as follows: rate = (9.92 ± 0.41 x 103[H2PO4-] + 5.70 ± 0.52 x 108[H3O+] + 5.3 ± 0.2)[SO32-][Cl- Leu-Ala] (concentrations in M, time in s). Rate constants for other peptides appear to be of similar magnitude; variations in the acid-catalyzed terms among different hydrophobic peptides correlate with solvation energies of side chains. The kinetic data suggest that reducing N-chloropeptides in wastewaters by 75% or more will require reaction times generally >0.5 h at environmentally acceptable S(IV) doses and pH values. Biologically induced fragmentation of proteins during wastewater treatment produces peptides, which form long-lasting organic chloramines when the water is disinfected with Cl2. To protect aquatic wildlife from residual chlorine, including chloramines, wastewaters are often treated with sulfur dioxide or sulfite salts. This strategy incompletely eliminates residual chlorine species. Here we report that dechlorination rate constants of N-chloropeptides are 1-2 orders of magnitude smaller than those for NH2Cl and some aliphatic organic chloramines. Slow rates explain the prevalence of N-chloropeptides in dechlorinated wastewaters after faster reacting chlorine species have been eliminated. Dechlorination is subject to general acid catalysis. For N-chlorinated leucylalanine, the rate law above pH 6 in phosphate buffer at 25 °C and I≈0.1 M is as follows: rate = (9.92±0.41×103[H2 PO4- ]+5.70±0.52×108[ H3O+]+5.3±0.2) [SO32-][Cl-Leu-Ala] (concentrations in M, time in s). Rate constants for other peptides appear to be of similar magnitude; variations in the acid-catalyzed terms among different hydrophobic peptides correlate with solvation energies of side chains. The kinetic data suggest that reducing N-chloropeptides in wastewaters by 75% or more will require reaction times generally >0.5 h at environmentally acceptable SIV doses and pH values.
- Jensen, James S.,Helz, George R.
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p. 516 - 522
(2007/10/03)
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- " Mediator Methodology" for the Synthesis of Peptides in a Two-Polymeric System
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Abstract: A novel methodology is described for a potential automated self-controlled synthesis of peptides.The method is based on transferring an N-protected amino acid from one insoluble polymer (donor) such as a polymeric o-nitrophenyl ester (a "bank" of active ester) to an insoluble polymer-bound amino acid (acceptor),with the aid of a soluble mediator molecule (shadchan)2 The method gives high yields of pure peptides by garanteeing stoichiomeric supply of the active ester and allowing self monitoring.When the polymer-bound (dimethylamino)pyridinium salts, the condensation reaction was expended to also include sulfonation and particularly phosphorylation reactions.
- Shai, Yechiel,Jacobson, Kenneth A.,Patchornik, Abraham
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p. 4249 - 4252
(2007/10/02)
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