17430-65-8Relevant articles and documents
Gold-catalyzed direct alkynylation of tryptophan in peptides using TIPS-EBX
Tolnai, Gergely L.,Brand, Jonathan P.,Waser, Jerome
supporting information, p. 745 - 749 (2016/07/06)
The selective functionalization of peptides containing only natural amino acids is important for the modification of biomolecules. In particular, the installation of an alkyne as a useful handle for bioconjugation is highly attractive, but the use of a carbon linker is usually required. Herein, we report the gold-catalyzed direct alkynylation of tryptophan in peptides using the hypervalent iodine reagent TIPS-EBX (1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one). The reaction proceeded in 50-78% yield under mild conditions and could be applied to peptides containing other nucleophilic and aromatic amino acids, such as serine, phenylalanine or tyrosine.
Diazonamide studies. A direct synthesis of the indole bis-oxazole fragment from tri- and tetra-peptides using biomimetic oxidative cyclizations
Sperry, Jonathan,Moody, Christopher J.
experimental part, p. 6483 - 6495 (2010/10/19)
The oxidation of several readily prepared tryptophan containing tri- and tetrapeptides with DDQ results in a biomimetic cyclization and direct formation of the indole bis-oxazole fragment of diazonamide A, establishing that such a transformation is a viab
Conformational effects in reversed-phase liquid chromatographic separation of diastereomers of cyclic dipeptides
Funasaki, Noriaki,Hada, Sakae,Neya, Saburo
, p. 1861 - 1867 (2007/10/02)
The capacity factors, k′, of 11 cyclic dipeptides (X-Y) including diastereomers have been determined on an RP-HPLC column in 30% and 50% methanol and 10%, 30%, and 50% acetonitrile solutions. These factors are roughly correlated with hydrophobic parameters, such as octanol-water partition coefficients estimated and k′ values for alcohols. For a pair of diastereomers of cyclic (L-X-L-Phe) and (L-X-D-Phe) derivatives k′LL is larger than k′LD and for cyclic (D-Ala-L-Trp) and (L-Ala-L-Trp) k′LL is smaller than k′DL, particularly in highly aqueous solutions. These elution orders can be well predicted by the holistic molecular surface area approach which takes into account the folded structures of cyclic dipeptides. The present results will be useful for prediction of the log k′ values of larger peptides and the hydrophobicity and related properties of peptides.
Peptide-titanium complex as catalyst for asymmetric addition of hydrogen cyanide to aldehyde
Nitta, Hideaki,Yu, Donghai,Kudo, Masanobu,Mori, Atsunori,Inoue, Shohei
, p. 7969 - 7975 (2007/10/02)
The complex of titanium ethoxide and an acyclic dipeptide ester whose terminal amino group is modified to a salicylal-type Schiff base catalyzes the asymmetric addition of hydrogen cyanide to aldehydes with high enantioselectivity. In the reaction of benzaldehyde and hydrogen cyanide, (R)-mandelonitrile is obtained with an enantiomeric excess of 90% when N-((2-hydroxy-1-naphthyl)methylene)-(S)-valyl-(S)-tryptophan methyl ester is employed. In place of the dipeptide, the amide derivatives of an amino acid modified by substituted salicylaldehyde, such as N-(3,5-dibromosalicylidene)-(S)-valine piperidide, exhibit an entirely opposite stereoselectivity to yield S-cyanohydrins with optical purities up to 97% ee. This novel peptide-titanium complex, therefore, enables us to afford optically active cyanohydrins of both absolute configurations by using natural S-amino acids as chiral auxiliaries.
