160464-32-4Relevant academic research and scientific papers
Rational design of an organocatalyst for peptide bond formation
Handoko,Satishkumar, Sakilam,Panigrahi, Nihar R.,Arora, Paramjit S.
supporting information, p. 15977 - 15985 (2019/10/11)
Amide bonds are ubiquitous in peptides, proteins, pharmaceuticals, and polymers. The formation of amide bonds is a straightforward process: amide bonds can be synthesized with relative ease because of the availability of efficient coupling agents. However, there is a substantive need for methods that do not require excess reagents. A catalyst that condenses amino acids could have an important impact by reducing the significant waste generated during peptide synthesis. We describe the rational design of a biomimetic catalyst that can efficiently couple amino acids featuring standard protecting groups. The catalyst design combines lessons learned from enzymes, peptide biosynthesis, and organocatalysts. Under optimized conditions, 5 mol % catalyst efficiently couples Fmoc amino acids without notable racemization. Importantly, we demonstrate that the catalyst is functional for the synthesis of oligopeptides on solid phase. This result is significant because it illustrates the potential of the catalyst to function on a substrate with a multitude of amide bonds, which may be expected to inhibit a hydrogen-bonding catalyst.
Synthesis of phakellistatin 11: A Micronesia (Chuuk) marine sponge cyclooctapeptide
Pettit,Lippert III,Taylor,Tan,Williams
, p. 883 - 891 (2007/10/03)
The cyclic octapeptide phakellistatin 11 (1), a constituent of The Federated States of Micronesia (Chuuk) marine sponge Phakellia sp., was synthesized using solid-phase techniques. An initial solution-phase synthesis proved to be inadequate owing to spontaneous deprotection of the Fmoc group at the heptapeptide stage. Using the PAL resin attachment and proceeding from Fmoc-Glu-α-allyl ester, linear elongation of the octapeptide was performed until the final unit Pro was added. The allyl ester was removed using Pd0[P(C6H5)3]4. Cleavage of the final Fmoc group and cyclization with PyAOP provided phakellistatin 11 (1) in 17% overall yield. The synthetic specimen of phakellistatin 11 (1) was found to be chemically but not biologically (cancer cell lines) identical to the natural product. The result suggested a conformational difference or more likely the presence of a trace amount of a highly active antineoplastic agent that binds noncovalently to the natural cyclic octapeptide 1.
Antineoplastic agents. 400. Synthesis of the Indian ocean marine sponge cyclic heptapeptide phakellistatin 2
Pettit, George R.,Rhodes, Monte R.,Tan, Rui
, p. 409 - 414 (2007/10/03)
Solution-phase synthesis of the marine sponge constituent phakellistatin 2 (1), cyclo(Tyr-Pro-Phe-Pro-Ile-Ile-Pro), was completed using a combination of stepwise coupling and (4 + 3) segment condensation. Use of diethyl phosphorocyanidate for the peptide bond formations gave the linear heptapeptide in 54% yield. Cyclization was achieved in high yields utilizing TBTU (2), BOP-C1 (3), PyBroP (4), and HOAt (5), resulting in 50-65% yields of phakellistatin 2 (1) depending on the method employed. The synthetic cyclic peptide was chemically but not biologically identical with the natural product.
Specific fragmentation of thioxo peptides facilitates the assignment of the thioxylated amino acid
Pfeifer, Thomas,Schierhorn, Angelika,Friedemann, Rudolf,Jakob, Mario,Frank, Robert,Schutkowski, Mike,Fischer, Gunter
, p. 1064 - 1071 (2007/10/03)
Low-energy collision-induced dissociation (CID) product ion spectra of a series of singly protonated thioxo peptides produced by electrospray ionization (ESI) were obtained by triple-quadrupole tandem mass spectrometry. The principal feature of the spectr
