3918-92-1Relevant articles and documents
Highly Productive Continuous Flow Synthesis of Di- and Tripeptides in Water
Jolley, Katherine E.,Nye, William,González Ni?o, Carlos,Kapur, Nikil,Rabion, Alain,Rossen, Kai,Blacker, A. John
, p. 1557 - 1565 (2017/10/25)
The reaction of amino acid derived N-carboxyanhydrides (NCAs) with unprotected amino acids under carefully controlled aqueous continuous flow conditions realized the formation of a range of di- and tripeptide products in 60-85% conversion at productivities of up to 535 g·L-1h-1. This required a fundamental understanding of the physicochemical aspects of the reaction resulting in the design of a custom-made continuous stirred tank reactor (CSTR) with continuous solids addition, high shear mixing, automated pH control to avoid the use of buffer, and efficient heat removal to control the reaction at 1 ± 1 °C.
Synthesis and NMR elucidation of pentacycloundecane-derived hydroxy acid peptides as potential anti-HIV-1 agents
Karpoormath, Rajshekhar,Albericio, Fernando,Govender, Thavendran,Maguire, Glenn E. M.,Kruger, Hendrik G.
, p. 1461 - 1471 (2013/10/22)
The synthesis and NMR elucidation of eight novel peptides incorporating the pentacycloundecane (PCU)-derived hydroxy acid are reported. The PCU cage amino acids were synthesized as racemates and the incorporation of the PCU-derived hydroxy acid with natural (S)-amino acids produced inseparable diastereomeric peptides. A series of overlapping signals from the cage and that of the peptide side chain was observed in the 1H- and 13C-NMR spectra, complicating the elucidation thereof. Two-dimensional NMR techniques proved to be a very useful tool in overcoming these difficulties. These compounds are potential HIV protease inhibitors.
Direct asymmetric intermolecular aldol reactions catalyzed by amino acids and small peptides
Cordova, Armando,Zou, Weibiao,Dziedzic, Pawel,Ibrahem, Ismail,Reyes, Efraim,Xu, Yongmei
, p. 5383 - 5397 (2008/02/13)
In nature there are at least nineteen different acyclic amino acids that act as the building blocks of poly-peptides and proteins with different functions. Here we report that α-amino acids, β-amino acids, and chiral amines containing primary amine functions catalyze direct asymmetric intermolecular aldol reactions with high enantio-selectivities. Moreover, the amino acids can be combined into highly modular natural and unusual small peptides that also catalyze direct asymmetric intermolecular aldol reactions with high stereoselectivities, to furnish the corre sponding aldol products with up to > 99% ee. Simple amino acids and small peptides can thus catalyze asymmetric aldol reactions with stereoselectivities matching those of natural enzymes that have evolved over billions of years. A small amount of water accelerates the asymmetric aldol reactions catalyzed by amino acids and small peptides, and also increases their stereoselectivities. Notably, small peptides and amino acid tetrazoles were able to catalyze direct asymmetric aldol reactions with high enantioselectivities in water, while the parent amino acids, in stark contrast, furnished nearly racemic products. These results suggest that the prebiotic oligomerization of amino acids to peptides may plausibly have been a link in the evolution of the homochirality of sugars. The mechanism and stereochemistry of the reactions are also discussed.