- LYSINE ISOTOPOLOGUES, COMPOSITIONS COMPRISING THE SAME AND METHODS OF SYNTHESIS
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This invention relates to lysine isotopologues of Formulas I and 1-A, as described herein, and processes for synthesizing the same and derivatives and intermediates involved therein. In one aspect, described herein is a chemical compound comprising an isotopically labeled analog, i.e., an isotopologue of a standard or naturally occurring lysine. The lysine isotopologue is synthetically formed to have stable isotopes of elements incorporated at selected positions. As such, the lysine isotopologue has a molecular mass different from the mass of a standard or naturally occurring lysine.
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Paragraph 0159-0162
(2016/02/12)
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- Chiral octahedral complexes of cobalt(III) as "organic catalysts in disguise" for the asymmetric addition of a glycine schiff base ester to activated olefins
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Stereochemically inert and positively charged chiral complexes of cobalt(III) prepared from Schiff bases derived from chiral diamines and salicylaldehydes were shown to be efficient catalysts of the benchmark asymmetric phase-transfer Michael addition of nine activated olefins to O'Donnell's substrate. The reaction products had enantiomeric purities of up to 96%. DFT calculations were invoked to rationalize the stereochemistry of the addition.
- Maleev, Victor I.,North, Michael,Larionov, Vladimir A.,Fedyanin, Ivan V.,Savel'Yeva, Tatyana F.,Moscalenko, Margarita A.,Smolyakov, Alexander F.,Belokon, Yuri N.
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supporting information
p. 1803 - 1810
(2014/06/09)
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- Micropeptins from an Israeli fishpond water bloom of the cyanobacterium microcystis sp
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Seven new natural products, micropeptin MZ845 (1), micropeptin MZ859 (2), micropeptin MZ939A (3), micropeptin MZ925 (4), micropeptin MZ939B (5), micropeptin MZ1019 (6), and micropeptin MZ771 (7), as well as two known micropeptins, cyanopeptolin S (8) and cyanopeptolin SS (9), were isolated from the hydrophilic extract of the cyanobacterium Microcystis sp. that was collected from a fishpond in Kibbutz Ma'ayan Tzvi, Israel, in July 2006. The structures of the pure natural products were elucidated using spectroscopic methods, including UV, 1D and 2D NMR, and MS techniques. The absolute configuration of the chiral centers of the compounds was determined using Marfey's method for HPLC. The inhibitory activity of the compounds was determined for the serine proteases: trypsin, chymotrypsin, thrombin, and elastase. These micropeptins inhibited trypsin with IC50's that varied between 0.6 and 24.2 μM. The SAR of these micropeptins is discussed.
- Zafrir, Ella,Carmeli, Shmuel
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experimental part
p. 352 - 358
(2010/08/05)
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- Resolution of DL-racemic mixtures
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The present invention relates to a process for the resolution of DL-racemic mixtures of compounds which crystalize in the form of a conglumerate. Both, the D and L-enantiomers are obtained according to the invention in a industrially feasable process by adding chiral enantioselective polymers to the supersaturated solution of the racemat to inhibit crystalization of one enantiomer. Next a DL-racemic mixture of said compound is suspended in about twice the amount of the crystallized enantiomer. Consequently, the opposite enantiomer could be recovered by said suspension by physical separation.
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Page column 7-8
(2008/06/13)
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- Highly enantioselective synthesis of cyclic and functionalized α-amino acids by means of a chiral phase transfer catalyst
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The chiral quaternary ammonium salt 1 serves as phase transfer catalyst for the enantioselective conversion of the glycine derivative 2 to a variety of cyclic and acyclic chiral α amino acids with enantioselectivities as high as 200:1 in alkylation and Michael addition reactions.
- Corey,Noe, Mark C,Xu, Feng
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p. 5347 - 5350
(2007/10/03)
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- DESIGN OF STEREOSPECIFIC INHIBITORS FOR CRYSTAL DISSOLUTION
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A new class of monomeric and polymeric crystal dissolution inhibitors has been prepared taking into consideration the packing arrangements and the morphologies of organic crystals.The efficiency of these inhibitors has been demonstrated by comparative morphological studies of α-glycine and by the kinetic resolution of the racemic conglomerates of his*HCl*H2O, threonine, glu*HCl, and 2,4-sec-phenetyl-3,5-dinitrobenzoate.
- Shimon, L. J. W.,Zbaida, D.,Addadi, L.,Leiserowitz, L.,Lahav, M.
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p. 199 - 222
(2007/10/02)
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- Synthesis of L-Glutamic Acid Labelled Stereospecifically at C-3 with Deuterium and Non-stereospecifically at C-4 with Tritium
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(2S,3S)-1>-, (2S,3R)-2>-, (2S,3S,4RS)-1,4-3H1>-, and (2S,3R,4RS)-2,4-3H1>-Glutamic acid have been synthesised from the corresponding labelled aspartic acids.The route involves a step where Wolff rearrangement occurs with retention of stereochemistry at a primary migrating chiral centre.The stereochemistry at C-3 of the glutamic acids has been verified by degradation to the corresponding stereospecifically labelled 1>succinic acids.
- Field, Steven J.,Young, Douglas W.
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p. 2387 - 2392
(2007/10/02)
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- Heterocyclic Prostaglandins. V. Synthesis of (12R,15S)-(-)-11-Deoxy-8-azaprostaglandin E1 and Related Compounds
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The synthesis of (12R,15S)-(-)-11-deoxy-8-azaprostaglandin E1 ((R)-1a) and three diastereomers ((R)-2a, (S)-1a, and (S)-2a) starting from optically active pyroglutamic acid ((R)-3 and (S)-3) is reported.Esterification of (R)-3 and NaBH4 reduction gave (R)-(-)-5-hydroxymethyl-2-pyrrolidinone ((R)-5).Ethoxyethylation of (R)-5 and N-alkylation with methyl 7-bromoheptanoate, followed by acid treatment, provided (R)-hydroxymethyl pyrrolidinone ((R)-8).The Collins oxidation of (R)-8 gave (R)-(-)-methyl 7-(5-formyl-2-oxo-1-pyrrolidine)heptanoate ((R)-9), which served as a key intermediate.The Wittig reaction of (R)-9 and dimethyl 2-oxoheptylphosphonate gave the (R)-enone ((R)-10a) which was converted to the (12R,15S)-enol ((R)-11a) and (12R,15R)-enol ((R)-12a) by NaBH4 reduction.Alkaline hydrolysis of (R)-11a and (R)-12a gave (R)-1a and (R)-2a in high yields.Similarly, the (S)-aldehyde ((S)-9) was prepared from (S)-3 and converted to the (12S,15S)-acid ((S)-1a) and (12S,15R)-acid ((S)-2a) by the same sequence of reactions used for the (R)-series.Some (12R,15S)-acid derivatives ((R)-1b-g) with a modified ω-chain were also synthesized.These analogs ((R)-1b-g) were also prepared from (R)-9 via synthetic sequences similar to that described above.Keywords - heterocyclic prostaglandin; (12R,15S)-(-)-11-deoxy-8-azaprostaglandin E1; (12R,15R)-(-)-11-deoxy-8-azaprostaglandin E1; (12S,15S)-(+)-11-deoxy-8-azaprostaglandin E1; (12S,15R)-(+)-11-deoxy-8-azaprostaglandin E1; (R)-(-)-methyl 7-(5-formyl-2-oxo-1-pyrrolidine)heptanoate; (S)-(+)-methyl 7-(5-formyl-2-oxo-1-pyrrolidine)heptanoate
- Saijo, Shigeyoshi,Wada, Masao,Himizu, Jun-ichi,Ishida, Akihiko
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p. 1449 - 1458
(2007/10/02)
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- THE FIRST CHEMICAL CONVERSION OF L-PROLINE TO L-GLUTAMIC ACID
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The ruthenium tetroxide oxidation of N-acyl-L-proline esters gave the corresponding L-pyroglutamic acid derivatives in good yields with no appreciable racemization, which lead to the first chemical conversion of L-proline to L-glutamic acid.
- Yoshifuji, Shigeyuki,Matsumoto, Hideyo,Tanaka, Ken-ichi,Nitta, Yoshihiro
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p. 2963 - 2964
(2007/10/02)
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