Enantioselective transaminations by dendrimeric enzyme mimics

Breslow, Ronald; Wei, Sujun; Kenesky, Craig S.

doi:10.1016/j.tet.2007.02.052

Cited by 26 publications

(9 citation statements)

References 25 publications

(5 reference statements)

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“…24). 533,534 Fréchet and co-workers 45 entrapped proline inside the hydrophobic core of a PEI derivative via hydrogen bond interactions and demonstrated that the resulting supramolecular catalyst preferentially yielded crossaldol products, as ,-unsaturated ketones, in various cross ketone/aldehyde condensations. 535…”

Section: Catalysis Inside Rigid Hostsmentioning

confidence: 99%

Supramolecular catalysis. Part 2: artificial enzyme mimics

et al. 2014

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The design of artificial catalysts able to compete with the catalytic proficiency of enzymes is an intense subject of research. Non-covalent interactions are thought to be involved in several properties of enzymatic catalysis, notably (i) the confinement of the substrates and the active site within a catalytic pocket, (ii) the creation of a hydrophobic pocket in water, (iii) self-replication properties and (iv) allosteric properties. The origins of the enhanced rates and high catalytic selectivities associated with these properties are still a matter of debate. Stabilisation of the transition state and favourable conformations of the active site and the product(s) are probably part of the answer. We present here artificial catalysts and biomacromolecule hybrid catalysts which constitute good models towards the development of truly competitive artificial enzymes.

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Section: Catalysis Inside Rigid Hostsmentioning

confidence: 99%

Supramolecular catalysis. Part 2: artificial enzyme mimics

et al. 2014

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“…15,18 In 1985, Tabushi and coworkers showed that b-cyclodextrin-pyridoxamineethylenediamine 19 was highly effective for the transamination, giving L-phenylalanine, L-tryptophan, and L-phenylglycine in 90-96% ee (Scheme 6). 19,20 Breslow and coworkers also investigated the asymmetric transamination with pyridoxamine analogues bound to chiral dendrimers 21,22 and polymers 23 (Scheme 7). For example, up to 66% ee was obtained for L-Val at the initial stage of the reaction with pyridoxamine 20 bound to chiral PEI 21 via hydrophobic interactions in 40% aqueous methanol at pH 7.3-7.8.…”

Section: Artificial Transaminase Mimicsmentioning

confidence: 99%

Progress in asymmetric biomimetic transamination of carbonyl compounds

et al. 2015

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Transamination of α-keto acids with transaminases and pyridoxamine phosphate is an important process to form optically active α-amino acids in biological systems. Various biomimetic transamination systems have been developed for carbonyl compounds including α-keto acid derivatives, fluoroalkyl ketones, and unactivated ketones with chiral vitamin B6 analogues, artificial transaminase mimics, chiral nitrogen sources, and chiral catalysts. This review provides a brief summary of this area.

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“…The cofactor activity of G3 4Pyr in the amine transfer from L-alanine to α-ketoglutarate suggests that activation of Pyr as a cofactor for transaminase occurs via covalent bonding of Pyr to PAMAM G3. Amine group transfer from pyridoxamine covalently incorporated into the core of PAMAM to phenylpyruvic and pyruvic acid, 34,35 as well as racemization of alanine by Pyr covalently incorporated into the core of polyethyleneimine dendrimers has been reported. 36 In order to characterize the roles of the PAMAM carrier and the PAMAM-PLP and PAMAM-Pyr bioconjugates further, we performed additional control experiments.…”

Section: Release Of Pyr and Plp From Bioconjugates And Transaminationmentioning

confidence: 99%

Bioconjugates of PAMAM dendrimers with trans-retinal, pyridoxal, and pyridoxal phosphate

Filipowicz¹,

Wołowiec²

2012

IJN

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Background: Bioconjugates of a polyamidoamine (PAMAM) G3 dendrimer and an aldehyde were synthesized as carriers for vitamins A and B 6 , and the bioavailability of these vitamins for skin nutrition was investigated. Methods: Nuclear magnetic resonance (NMR) and ultraviolet-visible methods were used to characterize the structure of the bioconjugates and for monitoring release of pyridoxal (Pyr) and pyridoxal phosphate (PLP) from these bioconjugates in vitro. A skin model permeation of bioconjugates was also studied in a Franz chamber. Results: A transdermal G3 PAMAM dendrimer was used to synthesize bioconjugates with trans-retinal (Ret), pyridoxal (Pyr), or PLP. These nanomolecules, containing up to four covalently linked Ret, Pyr, or PLP (G3 4Ret , G3 4Pyr , and G3 4PLP ), were able to permeate the skin, as demonstrated in vitro using a model skin membrane. PLP and Pyr bound to a macromolecular vehicle were active cofactors for glutamic pyruvic transaminase, as shown by 1 H NMR spectral monitoring of the progress of the L-alanine + α-ketoglutarate → glutamic acid + pyruvic acid reaction. Conclusion: PAMAM-PLP, PAMAM-Pyr, and PAMAM-Ret bioconjugates are able to permeate the skin. PLP and Pyr are available as cofactors for glutamic pyruvic transaminase.

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Enantioselective transaminations by dendrimeric enzyme mimics

Cited by 26 publications

References 25 publications

Supramolecular catalysis. Part 2: artificial enzyme mimics

Supramolecular catalysis. Part 2: artificial enzyme mimics

Progress in asymmetric biomimetic transamination of carbonyl compounds

Bioconjugates of PAMAM dendrimers with trans-retinal, pyridoxal, and pyridoxal phosphate

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