Results 251 to 260 of about 149,407 (284)

The excretion of 15N in urine after administration of 15N-glycine

Biochimica et Biophysica Acta, 1954
Abstract The 15 N-abundance was determined in urine from normal persons in nitrogen balance up to 360 hours after administration of 15 N-labelled glycine. It is shown that the 15 N-abundance in excess in urine with good approximation follows the equation: a = a 1 e − B 1 t + a 2 e − B 2 t + a 3 e − B 3 t By integration of ...
K, OLESEN, N C, HEILSKOV, F, SCHØNHEYDER   +2 more
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A two-step synthesis of benzylamine-15N from ammonia-15N

Journal of Labelled Compounds and Radiopharmaceuticals, 1978
The reaction of ammonia-15N with benzaldehyde in 50% aq. methanol followed by slow removal of solvent led to a high yield of a crystalline product (benzylimine-15N). On reduction with sodium cyanoborohydride a good yield of benzylamine-15N was obtained. The synthetic usefulness of this compound is discussed.
C. Gazzola, G. L. Kenyon
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15N MAS NMR Spectroscopy of [π-15N] and [τ-15N] histidine labelled bacterial photosynthetic reaction centres

1998
A characteristic feature of the bacterial reaction centre (RC) complex is a strictly apolar transmembrane helical region holding the cofactor branches, with each transmembrane helix containing a segment of at least 16 nonpolar residues (1). It is enclosed between the globular cytoplasmic H-subunit domain and the periplasmic surface layer of the complex,
C. Soede-Huijbregts, J. J. Cappon, G. J. Boender, J. Raap, P. Gast, A. J. Hoff, J. Lugtenburg, H. J. M. de Groot   +7 more
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Synthesis of DL-α-15N-tryptophan and 2-15N-perlolyrine

Journal of Labelled Compounds and Radiopharmaceuticals, 1998
DL-α- 15 N-Tryptophan was synthesized by simple and convenient chemical reduction method,starting from α- 15 N-glycine and benzoyl chloride via five steps. The yield of DL-α- 15 N-tryptophan from α- 15 N-glycine was 46.9%. 2- 15 N-Perlolyrine was synthesized from DL- α- 15 N-tryptophan and 5-acetoxymethyl-2-formylfuran via three steps.
Ganghua Tang, Shinchen Wang, Shuqin Wu, Guohui Jiang   +3 more
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Synthesis of 6-15N and 1-15N labeled adenosine monophosphates

Tetrahedron, 1988
Abstract A chemical synthesis of 6-15N and 1-15N AMPs from 5'-O-acety1-2',3'-O-isopropylideneinosine is reported.
Simon R. Sarfati, Vinod K. Kansal
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Synthesis and hyperpolarized 15N NMR studies of 15N-choline-d13

Tetrahedron, 2013
Abstract 15N-Choline-d13 was synthesized as a new biomarker for dynamic nuclear polarization, and the lifetime of the polarized signal governed by the spin–lattice relaxation time T1 was measured. 15N-Choline-d13 exhibited a T1 that was over twice as long as that of 15N-choline, and the hyperpolarized 15N signal could be observed for 1 h.
Keiko Kumagai, Kazuyasu Kawashima, Mai Akakabe, Masayuki Tsuda, Takamasa Abe, Masashi Tsuda   +5 more
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15N Chemical Shifts

1981
Compilation until 1979 of the literature on 15N parameters, namely chemical shifts and coupling constants, has provided a large amount of data. Examination of Fig. 1.1 shows that most 15N resonances lie in a 500 ppm range, although some compounds, such as nitroso derivatives, extend the field of δ 15N to 800 ppm.
Gérard J. Martin, Maryvonne L. Martin, Jean-Paul Gouesnard   +2 more
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Synthesis of 15N-labeled phthalimide

Applied Radiation and Isotopes, 2006
A new method for preparing 15N-labeled phthalimide from the reaction between phthalic anhydride and 15N-urea (99.34% 15N) in the presence of ortho-xylene is described in this work. Reaction conditions were the mole ratio of phthalic anhydride to 15N-urea (99.34% 15N) of 3-1 at 140 degrees C and under atmospheric pressure.
Zhanfeng, Liu, Qipeng, Yuan
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Méthodologie 15N

1997
2 tables 4 graph. Partie "Allocation de l'azote au cours de la croissance et du développement de la plante" chap.
Deléens, E., Morot-Gaudry, J.F., Martín, F., Thoreux, A., Gojon, Alain   +4 more
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