- Synthesis of alanine and proline amino acids with amino or guanidinium substitution on the side chain
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Competitive binding of peptides containing basic amino acids to disrupt or prevent the Tat-TAR interaction could result in diminished transcription as well as translation and hence constitutes an alternative way of controlling HIV replication. Therefore, we synthesized guanidinium and amino containing amino acids, based on a proline or an alanine scaffold. The introduction of the guanidinium moiety was best accomplished using 1H- pyrazole-1-carboxamidine hydrochloride, with Pmc used for its protection. The absence of racemization, maintained throughout the whole synthesis, was confirmed by chiral purity determination. These building blocks were smoothly incorporated into oligopeptides, which proved their suitability for use in a combinatorial approach for selecting TAR binding ligands. (C) 2000 Elsevier Science Ltd.
- Zhang, Zhenyu,Aerschot, Arthur Van,Hendrix, Chris,Busson, Roger,David, Frank,Sandra, Pat,Herdewijn, Piet
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p. 2513 - 2522
(2007/10/03)
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- Synthesis of (R)- and (S)-2,3-diaminopropyl sulfate: Mechanism based inhibition of glutamate 1-semialdehyde aminomutase
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A short synthesis of each enantiomer of 2,3-diaminopropyl hydrogensulfate is described starting from (2R)- and (2S)-asparagine. The compounds serve as inhibitors for pyridoxal 5'-phosphate-dependent (2S)- glutamate 1-semialdehyde aminotransferase, a target for selective herbicides and antibacterial agents on the tetrapyrrole biosynthetic pathway. The (2R)- enantiomer, as predicted, serves as a potent irreversible inactivator. (C) 2000 Elsevier Science Ltd.
- Khayer, Khurshida,Jenn, Thierry,Akhtar, Mahmoud,John, Robert,Gani, David
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p. 1637 - 1641
(2007/10/03)
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- SYNTHESIS OF PYROGLUTAMYLASPARAGINE AMIDE DIPEPTIDE FRAGMENT OF VASOPRESSIN, AND THE STEREOSELECTIVITY OF ITS MNEMIC EFFECT
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Four diastereomers of pGlu-Asn-NH2 were synthesized.They were considered on one hand as a peptide analogue of piracetam, and on the other as an N-terminal fragment of the major metabolite of vasopressin 4, Cyt6>AVP(4-9).The influence of these diastereomers on the memory of rats was studied in the passive avoidance conditioned reflex test.It was shown that L-pGlu-L-Asn-NH2 and D-pGlu-D-Asn-NH2 in the same doses facilitate the training of rats; D-pGlu-D-Asn-NH2 is inactive, and L-pGlu-D-Asn-NH2 has amnestic activity.These facts suggest a receptor mechanism for the action of the dipeptide pGlu-Asn-NH2 and are the basis for a hypothesis for the topology of the nootropic receptor binding site.
- Gudasheva, T. A.,Rozantsev, G. G.,Ostrovskaya, R. U.,Trofimov, S. S.,Voronina, T. A.,et al.
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- Substituted urido amino and imino acids and esters
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Compounds of the formula STR1 wherein X is various imino or amino acids or esters are disclosed. These compounds possess angiotensin converting enzyme inhibition activity and depending upon the definition of X also possess enkephalinase inhibition activit
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- Direct Optical Resolution of Carboxylic Acids by Chyral HPLC on Tris(3,5-dimethylphenylcarbamate)s of Cellulose and Amylose
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A variety of racemic carboxylic acids have been for the first time directly resolved by normal-phase, high-performance liquid chromatography using a hexane-2-propanol eluting system containing a small amount (ca. 1percent) of a strong carboxylic acid, like formic acid, trichloroacetic acid, and trifluoroacetic acid.
- Okamoto, Yoshio,Aburatani, Ryo,Kaida, Yuriko,Hatada, Koichi
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p. 1125 - 1128
(2007/10/02)
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- Nonapeptides and methods for their production
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New nonapeptides having the formula Prot Grp-R-Trp-Ser-Tyr-R2 -Leu-Arg-Pro-Gly-R3 ; salts thereof; wherein R is Gln, Gln (bzl), His (bzl), Ser (bzl), Pro, Leu, Tyr (bzl), Ile, Cys (bzl) or Phe, R2 is D-Phe, D-Ala, D-Leu, D-Trp, D-Tyr, D-Tyr (Me), D-Ser, D-Met, D-Arg, D-Val, D-His, D-Gln, D-Phs, D-Thr, D-Pro or D-Asn and R3 is NH2, NH(lower alkyl) or N-(lower alkyl)2, methods for their production; certain peptide intermediates and their salts used in the production thereof; and the use of said nonapeptides as luteinizing hormone releasing factor antagonists.
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