- Highly Productive Continuous Flow Synthesis of Di- and Tripeptides in Water
-
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.
- Jolley, Katherine E.,Nye, William,González Ni?o, Carlos,Kapur, Nikil,Rabion, Alain,Rossen, Kai,Blacker, A. John
-
p. 1557 - 1565
(2017/10/25)
-
- Redox-triggered changes in the self-assembly of a ferrocene-peptide conjugate
-
Ultrasonication of a ferrocene conjugate of a short amyloid peptide (Aβ18-20) in toluene causes formation of an organogel, which undergoes dramatic structural changes upon oxidation from a nanofibrillar network to spherical micelles. This morphological change is redox-controlled and reversible. the Partner Organisations 2014.
- Adhikari, Bimalendu,Kraatz, Heinz-Bernhard
-
p. 5551 - 5553
(2014/05/20)
-
- Synthesis and NMR elucidation of pentacycloundecane-derived hydroxy acid peptides as potential anti-HIV-1 agents
-
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.
- Karpoormath, Rajshekhar,Albericio, Fernando,Govender, Thavendran,Maguire, Glenn E. M.,Kruger, Hendrik G.
-
p. 1461 - 1471
(2013/10/22)
-
- The small peptide-catalyzed direct asymmetric aldol reaction in water
-
The asymmetric aldol reaction is a powerful method for forming carbon-carbon bonds. Small peptides with a primary amine as the catalytic residue catalyze asymmetric aqueous aldol reactions between unmodified ketones and aldehydes to furnish the corresponding aldol products with high ees. The high momodularity of the small peptides should enable the construction of several novel catalysts by combinatorial techniques for the aqueous asymmetric aldol reaction. The remarkably high difference in stereoselectivity between the peptide bond-formation was an important step towards the evaluation of asymmetric catalysis and homochilarity.
- Dziedzic, Pawel,Zou, Weibiao,Hafren, Jonas,Cordova, Armando
-
-
- Direct asymmetric intermolecular aldol reactions catalyzed by amino acids and small peptides
-
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.
- Cordova, Armando,Zou, Weibiao,Dziedzic, Pawel,Ibrahem, Ismail,Reyes, Efraim,Xu, Yongmei
-
p. 5383 - 5397
(2008/02/13)
-
- Small peptides as modular catalysts for the direct asymmetric aldol reaction: Ancient peptides with aldolase enzyme activity
-
Simple peptides and their analogues having a primary amino group as the catalytic residue mediate the direct asymmetric intermolecular aldol reaction with high stereoselectivity and furnish the corresponding aldol products with up to 99% ee; this intrinsic ability of highly modular peptides may explain the initial molecular evolution of aldolase enzymes. The Royal Society of Chemistry 2005.
- Zou, Weibiao,Ibrahem, Ismail,Dziedzic, Pawel,Sunden, Henrik,Cordova, Armando
-
p. 4946 - 4948
(2007/10/03)
-
