55666-11-0Relevant articles and documents
Enantioselective Synthesis of Chiral Substituted 2,4-Diketoimidazolidines and 2,5-Diketopiperazines via Asymmetric Hydrogenation
Xiao, Guiying,Xu, Shuang,Xie, Chaochao,Zi, Guofu,Ye, Weiping,Zhou, Zhangtao,Hou, Guohua,Zhang, Zhanbin
supporting information, p. 5734 - 5738 (2021/08/01)
An enantioselective hydrogenation of 5-alkylidene-2,4-diketoimidazolidines (hydantoins) and 3-alkylidene-2,5-ketopiperazines catalyzed by the Rh/f-spiroPhos complex under mild conditions has been developed, which provides an efficient approach to the highly enantioselective synthesis of chiral hydantoins and 2,5-ketopiperazine derivatives with high enantioselectivities up to 99.9% ee.
Independent valine and leucine isotope labeling in Escherichia coli protein overexpression systems
Lichtenecker, Roman J.,Weinhaeupl, Katharina,Reuther, Lukas,Schoerghuber, Julia,Schmid, Walther,Konrat, Robert
, p. 205 - 209 (2014/01/06)
The addition of labeled α-ketoisovalerate to the growth medium of a protein-expressing host organism has evolved into a versatile tool to achieve concomitant incorporation of specific isotopes into valine- and leucine-residues. The resulting target proteins represent excellent probes for protein NMR analysis. However, as the side-chain resonances of these residues emerge in a narrow spectral range, signal overlap represents a severe limitation in the case of high-molecular-weight NMR probes. We present a protocol to eliminate leucine labeling by supplying the medium with unlabeled α-ketoisocaproate. The resulting spectra of a model protein exclusively feature valine signals of increased intensity, confirming the method to be a first example of independent valine and leucine labeling employing α-ketoacid precursor compounds.
Process for production of hydantoin derivatives
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, (2008/06/13)
Hydantoin derivatives are industrially advantageously produced at a high yield by reacting hydantoin with carbonyl compounds in the presence of (i) amino acids or the salts thereof and (ii) inorganic alkali compounds for a relatively short reaction time in an aqueous medium.