142-73-4Relevant articles and documents
Thermodynamic Parameters of Coupled Chemical Reactions from Temperature Jump Relaxation Amplitudes
Ushio, Hidetoshi,Trimm, Harold H.,Patel, Ramesh C.,Zemany, Michael D.
, p. 39 - 50 (1981)
Equations describing the temperature jump amplitudes associated with a system of two coupled reactions (TRIS - phenol red) as well as the ternary system (Mg(2+) - iminodiacetic acid - phenol red) are presented.The thermodynamic parameters calculated from experimentally measured temperature perturbation amplitudes using a multiparametric curve fitting procedure are found to be in good agreement with those determined from pH- and constant rate thermometric titrations.For phenol red, pKI = 7.55, ΔHI = 3.45 kcal, and for Mg(2+) iminodiacetic acid , logKM = 2.84, ΔHM = 3.25 kcal, were obtained.It is shown that this method can be used to determine accurate thermodynamic enthalpy changes over a narrow temperature interval of less than 1.0 deg C from a single experiment requiring about 50 μl of sample solution.
Biotransformation of iminodiacetonitrile to iminodiacetic acid by Alcaligenes faecalis cells immobilized in ACA-membrane liquid-core capsules
Zhang, Jin-Feng,Liu, Zhi-Qiang,Zhang, Xin-Hong,Zheng, Yu-Guo
, p. 53 - 64 (2014)
Biotransformation of iminodiacetonitrile (IDAN) to iminodiacetic acid (IDA) was investigated with a newly isolated Alcaligenes faecalis ZJUTBX11 strain showing nitrilase activity in the immobilized form. To reduce the mass transfer resistance and to increase the toleration ability of the microorganisms to the toxic substrate as well as to enhance their ability to be reused, encapsulation of the whole cells in alginate-chitosan-alginate (ACA) membrane liquid-core capsules was attempted in the present study. The optimal pH and temperature for nitrilase activity of encapsulated A. faecalis ZJUTBX11 cells were 7.5 C and 35 C, respectively, which is consistent with free cells. Based on the Michaelis-Menten model, kinetic parameters of the conversion reaction with IDAN as the substrate were: K m = (17.6 ± 0.3) mmol L-1 and V max = (97.6 ± 1.2) μmol min-1 g -1 of dry cell mass for encapsulated cells and (16.8 ± 0.4) mmol L-1 and (108.0 ± 2.7) μmol min-1 g -1 of dry cell mass for free cells, respectively. After being recycled ten times, the whole cells encapsulated in ACA capsules still retained 90 % of the initial nitrilase activity while only 35 % were retained by free cells. Lab scale production of IDA using encapsulated cells in a bubble column reactor and a packed bed reactor were performed respectively.
A ZrO2-RGO composite as a support enhanced the performance of a Cu-based catalyst in dehydrogenation of diethanolamine
Wang, Yongsheng,Zhao, Zhenzhen,Zhao, Yunlu,Lan, Xiaolin,Xu, Weixiang,Chen, Li,Guo, Dongjie,Duan, Zhengkang
, p. 30439 - 30447 (2019)
The sintering resistance of supported Cu nanoparticle (NP) catalysts is crucial to their practical application in the dehydrogenation of diethanolamine (DEA). In this paper, co-precipitation, hydrothermal synthesis, and sol-gel condensation are used to form a new support material through chemical bonding between graphene oxide and ZrO2. The composite carriers prepared by the three methods are mixed with copper nitrate and ground using a ball mill. A series of Cu/ZrO2-reduced graphene oxide (RGO) composites were prepared by calcination under nitrogen at 450 °C for 3 h and hydrogen reduction at 250 °C for 4 h. The conversion of DEA to iminodiacetic acid (IDA) reached 96% with the Cu/ZrO2-RGO catalyst prepared by hydrothermal synthesis. The conversion rate of DEA is more than 80% following the reuse of the CZG-2 catalyst for twelve cycles. The various physicochemical characterization techniques show that the Cu/ZrO2-RGO layered and wrinkled nanostructures can improve catalytic stability and suppress the sintering of the supported Cu NPs during the catalytic dehydrogenation of diethanolamine. A synergistic effect between the RGO and the Cu nanoparticles is observed. The Cu nanoparticles with RGO have a better dispersibility, and a new nano-environment is created, which is the key to improving the efficiency of diethanolamine dehydrogenation. These new Cu/ZrO2-RGO catalysts show increased durability compared to commercially produced Cu/ZrO2 catalysts and show promise for practical applications involving diethanolamine dehydrogenation.
A Zinc(II) Photocage Based on a Decarboxylation Metal Ion Release Mechanism for Investigating Homeostasis and Biological Signaling
Basa, Prem N.,Antala, Sagar,Dempski, Robert E.,Burdette, Shawn C.
, p. 13027 - 13031 (2015)
Metal ion signaling in biology has been studied extensively with ortho-nitrobenzyl photocages; however, the low quantum yields and other optical properties are not ideal for these applications. We describe the synthesis and characterization of NTAdeCage, the first member in a new class of Zn2+ photocages that utilizes a light-driven decarboxylation reaction in the metal ion release mechanism. NTAdeCage binds Zn2+ with sub-pM affinity using a modified nitrilotriacetate chelator and exhibits an almost 6 order of magnitude decrease in metal binding affinity upon uncaging. In contrast to other metal ion photocages, NTAdeCage and the corresponding Zn2+ complex undergo efficient photolysis with quantum yields approaching 30 %. The ability of NTAdeCage to mediate the uptake of 65Zn2+ by Xenopus laevis oocytes expressing hZIP4 demonstrates the viability of this photocaging strategy to execute biological assays. Light-driven metal release: A photodecarboxylation reaction has been exploited to design a photocaged complex for Zn2+ with superior properties compared to other caged metal complexes. The photocage has been used to control the uptake of Zn2+ in frog oocytes expressing a human zinc transport protein.
Synthesis of Deuterated or Tritiated Glycine and Its Methyl Ester
Shevchenko,Andreeva,Nagaev, I. Yu.,Myasoedov
, p. 266 - 267 (2019/01/03)
Abstract: Heating glycine (Gly) and methyl glycinate (GlyOCH3) supported on 5% Pd/C or 5% Pt/C in a deuterium or tritium gas atmosphere gave the isotope-labeled products. The experiments were carried out at 180°C for 10 min. The deuterium atom inclusion under these conditions averaged up to 1.8 atoms per molecule for Gly and up to 1.0 atom per molecule for GlyOCH3. The reaction with tritium gas gave labeled products with a specific radioactivity of 27–31 Ci/mmol for Gly and 18 Ci/mmol for GlyOCH3.
