Stereoselective synthesis of stable isotope-labeled L-α-amino acids: Electrophilic amination of Oppolzer's acyl sultams in the synthesis of L-[15N]alanine, L-[15N]valine, L-[15N]leucine, L-[15N]phenylalanine and L-[1-13C, 15N]valine
摘要:
Using 1-chloro-1-[N-15]nitrosocyclohexane, we have prepared five L-[alpha-N-15]amino acids. The stereoselective electophillic hydroxyamination of (S)-acylbornane-10,2-sultams, followed by Zn-o/H+ reduction, and alkaline cleavage of the chiral auxiliary, gave the amino acids in 97.2-99.5% e.e. By starting with labeled (S)-acylbornane-10,2-sultams this stereoselective route could be to prepare many C-13 and/or N-15 isotopomers of alpha-amino acids.
The Biosynthesis of Branched Dialkylpyrazines in Myxobacteria
作者:Thorben Nawrath、Jeroen S. Dickschat、Brigitte Kunze、Stefan Schulz
DOI:10.1002/cbdv.201000158
日期:——
with [(15)N]valine was performed, resulting in the incorporation of the (15)N label. The results contradict a biosynthetic pathway via cyclic dipeptides, but rather point to a pathway on which valine is reduced to valine aldehyde. Its dimerization to 2,5-diisopropyldihydropyrazine 36 and subsequent oxidation results in 2. The proposed biosynthetic pathway neatly fits the results of earlier labeling studies
Hyperpolarization of Nitrogen‐15 Schiff Bases by Reversible Exchange Catalysis with
<i>para</i>
‐Hydrogen
作者:Angus W. J. Logan、Thomas Theis、Johannes F. P. Colell、Warren S. Warren、Steven J. Malcolmson
DOI:10.1002/chem.201602393
日期:2016.7.25
NMR with thermal polarization requires relatively concentrated samples, particularly for nuclei with low abundance and lowgyromagneticratios, such as 15N. We expand the substrate scope of SABRE, a recently introduced hyperpolarization method, to allow access to 15N‐enriched Schiff bases. These substrates show fractional 15N polarization levels of up to 2 % while having only minimal 1H enhancements
Chemo-enzymatic syntheses of isotopically labelled L-amino acids
作者:Nicholas M. Kelly、Bridget C. O'Neill、John Probert、Gordon Reid、Rosamund Stephen、Ting Wang、Christine L. Willis、Peter Winton
DOI:10.1016/s0040-4039(00)78265-7
日期:1994.8
L-Alanine labelled with carbon-13 and nitrogen-15 has been prepared in good yield and high optical purity from achiral precursors using alanine dehydrogenase This versatile approach may be simply adapted for the preparation of a range of isotopically labelled amino acids and efficient syntheses of [15N]-labelled serine, valine, leucine and phenylalanine are described.
Holl, Susan M.; Marshall, Garland R.; Beusen, Denise D., Journal of the American Chemical Society, 1992, vol. 114, # 12, p. 4830 - 4833
作者:Holl, Susan M.、Marshall, Garland R.、Beusen, Denise D.、Kociolek, Karol、Redlinski, Adam S.、Leplawy, Miroslaw T.、McKay, Robert A.、Vega, Shimon、Schaefer, Jacob