686-43-1Relevant articles and documents
Structure-CaSR-activity relation of kokumi γ-glutamyl peptides
Amino, Yusuke,Nakazawa, Masakazu,Kaneko, Megumi,Miyaki, Takashi,Miyamura, Naohiro,Maruyama, Yutaka,Eto, Yuzuru
, p. 1181 - 1189 (2016/08/11)
Modulation of the calcium sensing receptor (CaSR) is one of the physiological activities of γ-glutamyl peptides such as glutathione (γ-glutamylcysteinylglycine). γ-Glutamyl peptides also possess a flavoring effect, i.e., sensory activity of kokumi substances, which modifies the five basic tastes when added to food. These activities have been shown to be positively correlated, suggesting that kokumi γ-glutamyl peptides are perceived through CaSRs in humans. Our research is based on the hypothesis that the discovery of highly active CaSR agonist peptides will lead to the creation of practical kokumi peptides. Through continuous study of the structure-CaSR-activity relation of a large number of γ-glutamyl peptides, we have determined that the structural requirements for intense CaSR activity of γ-glutamyl peptides are as follows: existence of an N-terminal γ-L-glutamyl residue; existence of a moderately sized, aliphatic, neutral substituent at the second residue in an L-configuration; and existence of a C-terminal carboxylic acid, preferably with the existence of glycine as the third constituent. By the sensory analysis of γ-glutamyl peptides selected by screening using the CaSR activity assay, γ-glutamylvalylglycine was found to be a potent kokumi peptide. Furthermore, norvaline-containing γ-glutamyl peptides, i.e., γ-glutamylnorvalylglycine and γ-glutamylnorvaline, possessed excellent sensory activity of kokumi substances. A novel, practical industrial synthesis of regiospecific γ-glutamyl peptides is also required for their commercialization, which was achieved through the ring opening reaction of N-α-carbobenzoxy-L-glutamic anhydride and amino acids or peptides in the presence of N-hydroxysuccinimide.
N -boc deprotection and isolation method for water-soluble zwitterionic compounds
Liu, Zhijian,Yasuda, Nobuyoshi,Simeone, Michael,Reamer, Robert A.
, p. 11792 - 11796 (2015/02/19)
A highly efficient TMSI-mediated deprotection and direct isolation method to obtain zwitterionic compounds from the corresponding N-Boc derivatives has been developed. This method has been demonstrated in the final deprotection/isolation of the β-lactamase inhibitor MK-7655 as a part of its manufacturing process. Further application of this process toward other zwitterionic compounds, such as dipeptides and tripeptides, has been successfully developed. Furthermore, a catalytic version of this transformation has been demonstrated in the presence of BSA or BSTFA.
Rates of reduction of N-chlorinated peptides by sulfite: Relevance to incomplete dechlorination of wastewaters
Jensen, James S.,Helz, George R.
, p. 516 - 522 (2007/10/03)
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.
