637-84-3Relevant articles and documents
The effect of disorder on the chemical reactivity of an organic solid, tetraglycine methyl ester: Change of the reaction mechanism
Shalaev, Evgenyi,Shalaeva, Marina,Zografi, George
, p. 584 - 593 (2002)
Many drugs undergo chemical changes in the solid state, and understanding chemical reactivity of organic crystals is a critical factor in the drug development process. In this report, the impact of milling on the thermal chemical reactivity of an organic solid, tetraglycine methyl ester, was studied using DSC, isothermal calorimetry, chemical analysis (HPLC and insoluble residue determination), and powder X-ray diffraction. Significant changes in both X-ray diffraction patterns and DSC curves were detected after very brief milling (5 s). The changes were interpreted as the formation of a disordered phase. The disordered phase was tentatively identified as a crystal mesophase that combines properties of both crystalline (i.e., long-range order) and amorphous (i.e., glass transition) states. In the disordered material, the reaction mechanism changed from the methyl transfer reaction, which was observed in the intact crystal, to a polycondensation reaction when the reaction was performed at 165°C. Such changes in the reaction mechanism occurred in materials milled for > 30 s.
Mechanochemical Prebiotic Peptide Bond Formation**
Cindro, Nikola,Grube?i?, Sa?a,Hernández, José G.,Me?trovi?, Ernest,Stolar, Tomislav,U?arevi?, Krunoslav
supporting information, p. 12727 - 12731 (2021/05/07)
The presence of amino acids on the prebiotic Earth, either stemming from endogenous chemical routes or delivered by meteorites, is consensually accepted. Prebiotically plausible pathways to peptides from inactivated amino acids are still unclear as most oligomerization approaches rely on thermodynamically disfavored reactions in solution. Now, a combination of prebiotically plausible minerals and mechanochemical activation enables the oligomerization of glycine at ambient temperature in the absence of water. Raising the reaction temperature increases the degree of oligomerization concomitantly with the formation of a commonly unwanted cyclic glycine dimer (DKP). However, DKP is a productive intermediate in the mechanochemical oligomerization of glycine. The findings of this research show that mechanochemical peptide bond formation is a dynamic process that provides alternative routes towards oligopeptides and establishes new synthetic approaches for prebiotic chemistry.
Spontaneous and promoted association of linear oligoglycines
Gorokhova,Chinarev,Tuzikov,Tsygankova,Bovin
, p. 420 - 428 (2008/02/10)
Linear oligoglycines of various lengths bearing a carboxyl or an amide group at their C-termini and also their poly(acrylamide) conjugates were synthesized. No self-assembly into supramolecular structures was observed for free oligoglycines H-(Gly)m-OH (m = 3-5). At the same time, oligoglycylamides H-(Gly)m-NH2 (m = 3-5) demonstrated ability for both self-assembly in aqueous solution and assembly promoted by an additional interaction with surface. In the case of polymer-bound oligoglycines (and their amides), no intramolecular clustering of peptide chains, as expected, was observed. This means that the presence of several oligoglycine chains bound to each other in one center is not a necessary prerequisite for polyglycine II-type association. Pleiades Publishing, Inc., 2006.
Reaction of amino acids in a supercritical water-flow reactor simulating submarine hydrothermal systems
Islam, Md. Nazrul,Kaneko, Takeo,Kobayashi, Kensei
, p. 1171 - 1178 (2007/10/03)
A novel supercritical water flow-reactor was constructed in order to simulate submarine hydrothermal systems. The temperature of fluid inside the reaction tube could be monitored with thermocouples, which was proved to be different from the temperature outside the reaction tube. Oligomers of glycine up to tetraglycine were formed when a 100 mM glycine solution was heated at 200-350 °C for 2 minutes. None of glycine peptides were produced at 400 °C. It was suggested, however, that the formation of glycine condensates at higher temperature, including supercritical conditions of water. The stability of some amino acids under hydrothermal conditions was examined. ω-Amino acids and glutamic acid, which can form intramolecular condensates, showed higher stability than other α-amino acids at higher temperature, including supercritical conditions.
