- Hydrolytic cleavage of pyroglutamyl-peptide bond. I. The susceptibility of pyroglutamyl-peptide bond to dilute hydrochloric acid
-
The susceptibility of the pyroglutamyl-peptide bond in some biologically active peptides, dog neuromedin U-8 fragment (pGlu-Phe-Leu-Phe-Arg-Pro-Arg- OH), human big gastrin fragment (pGlu-Leu-Gly-Pro-OH) and thyrotropin releasing hormone (TRH) fragments (pGlu-His-Pro-OH, pGlu-His-OH), to 1 N HCl under mild conditions and/or at 60°C was studied. It was found that the N- terminal portion of pGlu-peptides is extremely labile to acid hydrolysis, giving not only the ring-opened product of the pyrrolidone moiety of the pGlu residue, but also the cleavage product of the pGlu-peptide linkage. The ring- opening reaction predominated over the cleavage reaction in hydrolysis of the four peptides in 1 N HCl at 60°C. The ring-opening reaction and the cleavage reaction of pGlu-peptide linkage proceeded faster than the cleavage of internal peptide bonds. The rate of hydrolysis was affected by the reaction temperature, and the ring-opening reaction was greatly diminished at 4°C in comparison with the cleavage reaction. Thus, the phenomenon that the pGlu- peptide bond is susceptible to dilute HCl as compared to the other peptide bonds appears to be a general one.
- Hashimoto,Ohki,Sakura
-
-
Read Online
- High Performance Liquid Chromatography (HPLC.) of Natural Products. III . Isolation of New Tripeptides from the Fermentation Broth of P. Chrysogenum
-
α-Aminoadipoyl-alanyl-valine, α-aminoadipoyl-serinyl-valine and α-aminoadipoyl-serinyl-isodehydrovaline have been isolated from the fermentation broth of P. chrysogenum.The configuration of α-aminoadipoyl-serinyl-valine has been shown to be L, L, D.
- Neuss, N.,Miller, R. D.,Affolder, C. A.,Nakatsukasa, W.,Mabe, J.,et al.
-
-
Read Online
- Preparation method of beta-homoglutamic acid
-
The invention belongs to the field of preparation of organic compounds, and provides a preparation method of beta-homoglutamic acid. The method is characterized in that: 3-cyclohexenecarboxylic acid is used as a raw material, beta-homoglutamic acid is synthesized at a high yield through three the steps of reactions of Curtius rearrangement, olefin oxidation and protection group removal, and beta-homoglutamic acid with high yield and high optical purity can be obtained through configuration retention by using optically pure 3-cyclohexenecarboxylic acid. The method has the advantages of easily available raw materials, mild reaction conditions and low cost, and is suitable for large-scale preparation of beta-homoglutamic acid.
- -
-
Paragraph 0022; 0031-0032
(2020/11/05)
-
- Colony-wise Analysis of a Theonella swinhoei Marine Sponge with a Yellow Interior Permitted the Isolation of Theonellamide i
-
There are several examples of marine organisms whose metabolic profiles differ among conspecifics inhabiting the same region. We have analyzed the metabolic profile of each colony of a Theonella swinhoei marine sponge with a yellow interior and noticed the patchy distribution of one metabolite. This compound was isolated and its structure was studied by a combination of spectrometric analyses and chemical degradation, showing it to be a congener in the theonellamide class of bicyclic peptides. Theonellamides had previously been isolated by us only from T. swinhoei with a white interior and not from those with a yellow interior.
- Fukuhara, Kazuya,Takada, Kentaro,Watanabe, Ryuichi,Suzuki, Toshiyuki,Okada, Shigeru,Matsunaga, Shigeki
-
p. 2595 - 2599
(2018/12/13)
-
- Peculiar stability of amino acids and peptides from a radical perspective
-
(Chemical Equation Presented) Photochemical reactions of free and N-acetyl α-amino acids with chlorine and deuterium labeled hydrogen peroxide have been used to determine both the relative rates of reaction of molecules of these classes and the relative reactivity of their different types of hydrogen toward abstraction by chlorine and oxygen centered radicals. The relative rates of reaction of these species range over more than 3 orders of magnitude; however, where data are available from more than one amino acid for a particular type of group at a specific position on the side chain, the values are remarkably similar. The predictive utility of these results has been demonstrated for the regioselective chlorination of tripeptides. More generally this analysis shows that the backbone and adjacent side chain positions of amino acids and peptides are peculiarly resistant to hydrogen atom transfer, and a similar pattern of reactivity has been noted from earlier studies of reactions of modified substrates catalyzed by isopenicillin-N-synthetase. Such resistance stands out in contrast to the common occurrence of free radical reactions of α-amino acids, peptides, and proteins and their importance in biology. Nevertheless, it provides a reason for the ability of amino acids and their derivatives to avoid degradation in Nature where they are constantly exposed to radicals, and it accounts, at least in part, for the anomalous ability of enzymes to catalyze free radical reactions without being broken down by the radical intermediates.
- Watts, Zachary I.,Easton, Christopher J.
-
supporting information; experimental part
p. 11323 - 11325
(2011/03/19)
-
- WA8242A1, A2 and B, novel secretary phospholipase A2 inhibitors produced by Streptomyces violaceusniger. III. Structure elucidation and total synthesis of WA8242B
-
The structure of WA8242B, a potent novel inhibitor against phospholipase A2, was fully characterized by spectroscopic methods and chemical degradation. The success of total synthesis of WA8242B confirmed the structure and allowed the pharmacological study of WA8242B. The structures of WA8242A1 and A2 were also described.
- Yoshimura, Seiji,Otsuka, Takanao,Takase, Shigehiro,Okamoto, Masanori,Okada, Satoshi,Hemmi, Keiji
-
p. 655 - 664
(2007/10/03)
-
- Enantiocontrolled synthesis of two amino acids; (S)-glutamic acid and (S)-2-aminoadipic acid
-
An efficient enantiocontrolled route to two acidic amino acids, (S)-glutamic acid and (S)-2-aminoadipic acid, has been developed starting from chiral equivalents of cyclopentadienone and cyclohexadienone, respectively.
- Takano,Kamikubo,Moriya,Ogasawara
-
p. 601 - 604
(2007/10/02)
-
- Simultaneous Production of D-Pipecolic Acid and L-α-Aminoadipic Acid from DL-Pipecolic Acid Using a Microorganism
-
The production of D-pipecolic acid from DL-pipecolic acid using a microbe was investigated.Some bacteria which assimilated L-pipecolic acid in preference to D-pipecolic acid and accumulated L-α-aminoadipic acid extracellularly when cultivated on DL-pipecolic acid were isolated.When one of these bacteria, which was designated as Alcaligenes sp. 309B1, was cultivated on a medium containing 5percent of DL-pipecolic acid, it assimilated all of the L-pipecolic acid, with most of the D-pipecolic acid not being assimilated.Ninety-five percent of the D-pipecolic acid remained after the complete disappearance of L-pipecolic acid from the culture broth.The amount of L-α-aminoadipic acid accumulated in the broth reached 56percent of the total quantity of L-pipecolic acid.
- Mochizuki, Kazuya,Yamazaki, Yoshimitsu,Maeda, Hidekatsu
-
p. 1113 - 1116
(2007/10/02)
-
- Chemical Conversion of L-α,ο-Diamino Acids to L-ο-Carbamoyl-α-amino Acids by Ruthenium tetroxide Oxidation
-
Ruthenium tetroxide oxidation of N,C-protected derivatives of L-2,4-diaminobutyric acid, L-ornitine and L-lisine was carried out two-phase conditions and the corresponding imides, formed through the oxidation of the methylene adjacent to the ο-amino group, were obtained in good yields.Removal of the protecting groups from the products gave L-asparagine, L-glutamine and L-2-aminoadipic acid 6-amide, respectively.Thus the first chemical conversion of L-α,ο-diamino acids into the corresponding L-ο-carbamoyl-α-amino acids without racemization has been established.L-2-Aminoadipic acid 6-amide was further converted to L-2-aminoadipic acid by acid hydrolysis.This represents a convenient method for the synthesis of L-2-aminoadipic acid starting from L-lisine.Keywords - oxidation; ruthenium tetroxide; L-α-amino acid synthesis; N-protecting group; ruthenium tetroxide; L-α,ο-diamino acid; L-ο-carbamoiyl-α-amino acid; L-2-aminoadipicacid
- Yoshifuji, Shigeyuki,Tanaka, Ken-ichi,Nitta, Yoshihiro
-
p. 2994 - 3001
(2007/10/02)
-
- Synthesis of Thyrotropin-Releasing Hormone Analogues. 2. Tripeptides Structurally Greatly Differing from TRH with High Central Nervous System Activity
-
A new series of thyrotropin-releasing hormone (TRH) analogues, obtained by further modifications of our most potent central nervous system (CNS) stimulating neutral tripeptides at both termini, were synthesized by the pentafluorophenyl ester method and tested for CNS and thyrotropin (TSH) releasing activity.Replacement of pyroglutamic acid by pyro-2-aminoadipic acid, 2-oxoimidazolidine-4-carboxylic acid or γ-butyrolactone-γ-carboxylic acid and that of proline by pipecolic acid, thiazolidine-4-carboxylic acid, or homoproline in 2>- and 2>TRH led to tripeptides structurally widely different from TRH.In spite of this fact, 7 of the 17 analogues (1, 2, 8-10, 16, and 17) have stronger anticataleptic effect than TRH, with negligible or no hormonal potency.The highest CNS activity was achieved when pyroglutamic acid was replaced by pyro-2-aminoadipic acid at the N-terminus .A novel synthesis of L-2-aminoadipic acid suitable for large-scale preparation is also described.
- Szirtes, Tamas,Kisfaludy, Lajos,Palosi, Eva,Szporny, Laszlo
-
p. 1654 - 1658
(2007/10/02)
-
- An Improved Method for Synthesis of L-Homoglutamic Acid via Epsilon-N-deamination of L-Lysine Derivative
-
A convenient procedure to prepare L-homoglutamic acid (L-2-aminoadipic acid; L-Aad) is described.Chlorination of ε-amino group in acetyl-L-lysine ethyl ester with t-butyl hypochlorite (t-BuOCl) followed by dehydrochlorination with pyridine gave ethyl 5-cy
- Kondo, Michio,Miyazaki, Koujiro,Kodama, Hiroaki,Horimoto, Hideaki
-
p. 1171 - 1173
(2007/10/02)
-
- SYNTHESIS OF THE RACEMIC AND OPTICALLY ACTIVE FORMS OF GIZZEROSINE, THE INDUCER OF GIZZARD EROSION IN CHICKS
-
The racemate end both the (R)- and (S)-forms of gizzerosine were synthesised, and the (S)-isomer was identified as the toxic substance in fish meal causing severe gizzard erosion (black vomit) in chicks.
- Mori, Kenji,Sugai, Takeshi,Maeda, Yukari,Okazaki, Tomomi,Noguchi, Tadashi,Naito, Hiroshi
-
p. 5307 - 5312
(2007/10/02)
-
- Mild and Simple Biomimetic Conversion of Amines to Carbonyl Compounds
-
4-Formyl-1-methylpyridinium benzenesulfonate is a convenient reagent for the chemical modification of primary amines to aldehydes and ketones.This method mimics the biological process for transamination reactions with pyridoxal (vitamin b6).As in that process, it involves imine formation, prototropic rearrangement, and hydrolysis.The conditions are extremely mild and are compatible with a large variety of sensitive functional groups.This process provides a simple and a efficient alternative to the somewhat harsher procedures generally employed for such transformations.
- Buckley, Thomas F.,Rapoport, Henry
-
p. 4446 - 4450
(2007/10/02)
-
- Synthesis of (R)-5-Aminohex-2-enedioic acid and the (+/-)-2-Bromo Derivative as Unsaturated Analogues of the Neurotransmitter Antagonist D-&α-Aminoadipic Acid
-
5-Aminohex-2-enedioic acid (2), an unsaturated analogue of the neurotransmitter antagonist D-α-aminoadipic acid, has been synthesised by a convenient route using a phase-transfer alkylation of N-diphenylmethyleneglycine ethyl ester.The unsaturated amino acid has been resolved and the absolute stereochemistry of the (-) isomer determined as R by reduction to D-α-aminoadipic acid.A more conventional synthetic scheme failed to yield (2), but led to the preparation of the (+/-)-2-bromo derivative (4) in low yield.
- Allan, Robin D.
-
p. 4658 - 4667
(2007/10/02)
-
