56618-30-5Relevant academic research and scientific papers
Cyclic Peptidic Mimetics of Apollo Peptides Targeting Telomeric Repeat Binding Factor 2 (TRF2) and Apollo Interaction
Chen, Xia,Liu, Liu,Chen, Yong,Yang, Yuting,Yang, Chao-Yie,Guo, Tianyue,Lei, Ming,Sun, Haiying,Wang, Shaomeng
supporting information, p. 507 - 511 (2018/05/23)
Telomeric repeat binding factor 2 (TRF2) is a telomere-associated protein that plays an important role in the formation of the 3′ single strand DNA overhang and the "T loop", two structures critical for the stability of the telomeres. Apollo is a 5′-exonu
C-Alkylation of Peptides Containing Aminomalonate and (Amino)(cyano)acetate Residues
Matt, Thomas,Seebach, Dieter
, p. 1845 - 1895 (2007/10/03)
N-Acetyl-, N-[(tert-butoxy)carbonyl](Boc)-, and N-[(benzyloxy)carbonyl](Z)-protected tri-, penta-, and heptapeptide methyl esters, 1-8, with a central aminomalonate (Ama) (allyl, methyl, benzyl, or tert-butyl) or (amino)(cyano)acetate (Aca) residue have been prepared by conventional techniques (Schemes 4-6). The new peptides with acidic backbone-bound CH groups can be C-alkylated with primary alkyl, allyl, and benzyl halides, under mildly basic conditions (1 equiv. MeONa or t-BuOK in THF); also, they can be added to Michael acceptors such as acrylates, acrylonitrile, methyl vinyl ketone, or nitrostyrene (catalytic amounts of alkoxide bases in THF) (Schemes 7-16). In most cases, the products, 48-100, are formed in excellent yields (average of 77%); one of the epimeric products prevails (2:1 to > 20:1), and the epimers have been separated, isolated in pure form, and fully characterized (without configurational assignments); addition of the co-solvent 3,4,5,6-tetrahydro-1,3-dimethylpyrimidin-2(1H)-one (DMPU) or of LiBr may improve or even reverse the ratio of epimeric products formed; the heptapeptide derivative 8 had to be solubilized for alkylations in THF by the addition of 30 equiv. of LiBr. Cleavage of the Ama groups (benzyl with H2/Pd-C, t-Bu with HCl/Et2O) gave carboxylate derivatives which are actually peptides containing the alkylated aminomalonic acid, the lower homolog of aspartic acid, as residue in the central position. These acids are quite resistant to decarboxylation which had to be achieved by heating at reflux in THF in the presence of 2 equiv. of LiBr and of catalytic amounts of pyridine (Schemes 17 and 18). A one-step removal of the allyl aminomalonate group is possible with Pd/PPh3/formate (Scheme 19). The resulting peptides, 101-115, were formed as separable 1:1 mixtures of two epimers. The CN group of the alkylated Aca residue can be removed reductively (Na/NH3; Scheme 20). The value of the new method is compared with that of existing methods of peptide-backbone modification.
Biodegradable microspheres. 16. Synthesis of primaquine-peptide spacers for lysosomal release from starch microparticles
Borissova,Lammek,Stjarnkvist,Sjoholm
, p. 249 - 255 (2007/10/02)
Classical procedures of peptide synthesis were applied to synthesize four groups of compounds, and analytical methods were developed for each of them. Two of the groups are tetrapeptide derivatives of the antileishmanial drug primaquine (PQ), with general structure NH2-X-Leu-Ala-Y-PQ. In the first group, Leu, Tyr, Lys, and Asp were used in the Y position, while X was Ala. In the second group, Ala, Tyr, Lys, and Asp were used in the X position, while Y was Leu. The derivatives are intended to be coupled, via their free α-amino group, to polyacryl starch microparticles, lysosomotropic drug carriers developed in our laboratory. Thus, a systematic study of the significance of the varying amino acid composition of the tetrapeptide spacer arm for the rate of lysosomal enzymatic release of PQ can be possible. A third group, composing ε-aminocaproic acid-PQ derivatives which lack a free α-amino group, was synthesized. This was done to study the importance of enzymes, other than aminopeptidases, during lysosomal degradation of these derivatives. To allow HPLC analysis of the pattern of degradation of tetrapeptide-PQ derivatives, some shorter peptide-PQ derivatives (group four) were prepared as well.
Chemical Modification of Peptides Containing γ-Carboxyglutamic Acid
Boggs, Norman T.,Bruton, H. David,Craig, Daniel H.,Helpern, Joseph A.,Marsh, Henry C.,et al.
, p. 1812 - 1816 (2007/10/02)
At acidic pH the γ-proton of the γ-carboxyglutamic acid (Gla) side chain undergoes rapid exchange.We have utilized the reactivity of the resulting enol form to develop a method for the chemical modification of peptide-bound Gla residues.Reaction of Gla pe
