Glycines, deuterated

Fig. 22 (a) 14N-13C SQ-HMQC spectrum of Ala Gly Gly tripeptide with natural abundance of 13C, taken at 14.1 T under 25 kHz MAS. The corresponding 15N MAS spectrum is shown in the top right comer. (Reproduced with permission from reference [258].) (b) l4N- H SQ-HMQC and DQ-HMQC spectra of partly deuterated glycine-d2 NH3+CD2COO, taken at 9.4 T under 30 kHz MAS. The 14N projections were simulated using second-order quadrupolar powder patterns with Cq = 1.18 MHz and i/q = 0.5, assuming uniform excitation of all crystallite orientations. (Reproduced with permission from [264])... 

IR spectra of starch can be obtained with an IR spectrometer such as a Digilab FTS 7000 spectrometer, Digilab USA, Randolph, MA, equipped with a thermoelectrically cooled deuterated tri-glycine sulfate (DTGS) detector using an attenuated total reflectance (ATR) accessory at a resolution of 4 cm by 128 scans. Spectra are baseline-corrected, and then deconvoluted between wavenumbers 1200 to 800 cm . A half-band width of 15 cm and a resolution enhancement factor of 1.5 with Bessel apodization are employed. Intensity measurements are performed on the deconvoluted spectra by recording the height of the absorbance bands from the baseline. 

Lippmaa and coworkers used 13C NMR titration to measure secondary deuterium IEs on acidities of carboxylic acids.24 The results are listed in Table 2. It is remarkable that the IEs show only a small attenuation with distance, so that the IE from three y-deuteriums in alanine is greater than that from two (3-deuteriums in glycine. As a consequence the IEs can be detected and measured from deuteriums as far as seven bonds away from the carboxyl, as in caproic-6,6,6-fl 3 acid. Moreover, in benzoic acids the IE is practically independent of the site of deuteration. 

Blackburn AC, Doe WF, Buffinton GD (1998) Salicylate hydroxylation as an indicator of OH radical generation in dextran sulfate-induced colitis. Free Rad Biol Med 25 305-313 Bonifacic M, Stefanic I, Hug GL, Armstrong DA, Asmus K-D (1998) Glycine decarboxylation The free radical mechanism. J Am Chem Soc 120 9930-9940 Bonifacic M, Armstrong DA, Stefanic I, Asmus K-D (2003) Kinetic isotope effect for hydrogen abstraction by OH radicals from normal and carbon-deuterated ethyl alcohol in aqueous solution. J Phys Chem B 107 7268-7276... 

The best clue to why this is so involves the chemical shifts of the OH, NH, and SH protons in these molecules. They are all the same within experimental error 4.90 p.p.m. for glycine, 4.80 p.p.m. for the aminothiol, and 4.84 p.p.m. for EDTA. They all correspond to the same species HOD. Exchange between XH (where X = O, N, or S) protons is extremely fast, and the solvent, D2O, supplies a vast excess of exchangeable deuteriums. These immediately replace all the OH, NH, and SH protons in the molecules with D, forming HOD in the process. Recall that we do not see signals for deuterium atoms (that s why deuterated solvents are used). They have their own spectra at a different frequency. 

In this section, we have discussed BPI( X)BPX and its deuterated analogues. Other system which is taken up for study is BPxGPI(i x) where BP is AFE and GPI (glycine phosphate) is FE. In contrast to BPI( X)BPX system, one can expect severe deviations as both cation and anion are different and also their cell dimensions also have quite a bit of mismatch. 

Fig. 2. (A) K-band ESP-EPR spectra of the CPI complex (top) and Rb sphaeroides R26 reaction-center complex (bottom) in the charge-separated states [P700 -A,4 and [P870 Q4, respectively (B) X-band ESP-EPR spectra of spinach PS-I particles extracted with a hexane-MeOH mixture (a), reconstituted with protonated (b) and deuterated (c) vitamin Ki (C) ESP-EPR spectra of spinach PS-I particle in glycine buffer at pH 10.8 and untreated (a), reduced with 50 mM dithionite and 0,5 mM methyl viologen and dark-incubated (b), and the reduced sample dialyzed overnight against glycine buffer and reconcentrated (c). Figure source (A) Petersen, Stehlik, Gast and Thurnauer (1987) Comparison of the electron spin polarized spectrum found in plant photosystem I and in iron-depleted bacterial reaction centers with time-resolved K-band EPR evidence that the photosystem I acceptor is a quinone. Photosynthesis Res 14 22 (B) and (C) Snyder and Thurnauer (1993) Electron spin polarization in photosynthetic reaction centers. In J Deisenhofer and JR Norris (eds) The Photosynthetic Reaction Center, Vol 11 313,315.

C.L. Thaper, B.A. Dasannacharya, P.S. Goyal, R. Chakravarthy J. Tomkinson (1991). Physica B, 174, 251-256. Neutron scattering from glycine and deuterated glycine. 

Suzuki et al. (1963) studied the spectra of normal and various deuterated glycines and also made band assignments for a-glycine. Some of the assignments made by Laulicht et al. (1966) differ from those made by Suzuki et al. (1963). For example. 

Infra-red spectra of the anion, cation, zwltterion and deuterated zwitterion forms of 1-deoxy-l-glycino-D-fructose, the glucose-glycine Amadori product, show the product to be predominantly in the -pyranose form. The synthesis, tautomeric equilibria in, and Fisher glycosldation of various l-deoxy-l-[(2,2-diacylvinyl) amino]-D-fructoses have been reported as part of a study on the use... 

Aliev et al. studied the high-resolution solid-state H MAS NMR studies of the alpha and gamma polymorphs of fully deuterated glycine-ds." Analysis of spinning sideband patterns is used to determine the H quad-... 

Pyroelectric transducers are constructed from single crystalline wafers of pyroelectric materials, which are insulators (dielectric materials) with very special thermal and electrical properties. Triglycinc sulfate (NH2CH2COOH)j H2SO4 (usually deuterated or with a fraction of the glycines replaced with alanine), is the most important pyroelectric material used for IR-detection systems. 

Radicals formed by reaction of Na with isobutyliodide. t) Not assigned to protons in specific positions, tt) This interpretation, of the ESR-spectra of irradiated glycine measurements on deuterated compounds [We 3. ... 

In addition, the rotational spectra of ten different isotopologues (one parent, one three and five deuterated species) for the two most stable conformers of alanine were detected. The extensive isotopic data were analyzed to derive the substitution [106, 107] and effective stmctures for both I and Ila conformers. Unlike glycine, the amino acid skeleton in alanine is non-planar. Deuteration at the amino and... 

The kinetics of stereoselective deuteration of malonate hydrogens in bis(malonato)-cobalt(III) complexes [Co(mal)2L2] containing L2 = en, pn, N,N -Me2en, phen, c/5 -(NH3)2, or c/5-(py)2 have been monitored. Both acid and base hydrolysis are observed, and there is a reversal of stereoselectivity with solution pH. There are some kinetic differences between the amine ligands on the one hand and py and phen on the other, as competition for OD" between malonate and amine is possible, between malonate and py or phen not. The rate law for deuteration of a hydrogens in a-aminocarboxylato complexes of cobalt(III) containing various combinations of glycine, sarcosine, or alanine with ammonia, ethylenediamine, or diaminopropane is simple second order. 

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