RÉSUMÉ
N-Substituted l-aspartic acids are important chiral building blocks for pharmaceuticals and food additives. Here we report the asymmetric synthesis of various N-arylalkyl-substituted l-aspartic acids using ethylenediamine-N,N'-disuccinic acid lyase (EDDS lyase) as a biocatalyst. This C-N lyase shows a broad non-natural amine substrate scope and outstanding enantioselectivity, allowing the efficient addition of structurally diverse arylalkylamines to fumarate to afford the corresponding N-arylalkyl-substituted l-aspartic acids in good isolated yield (up to 79%) and with excellent enantiopurity (>99% ee). These results further demonstrate that C-N lyases working in reverse constitute an extremely powerful synthetic tool to prepare difficult noncanonical amino acids.
Sujet(s)
Acide aspartiqueRÉSUMÉ
Brain tumours are among the deadliest tumours being highly resistant to currently available therapies. The proliferative behaviour of gliomas is strongly influenced by ion channel activity. Small-conductance calcium-activated potassium (SK/KCa) channels are a family of ion channels that are associated with cell proliferation and cell survival. A combined treatment of classical anti-cancer agents and pharmacological SK channel modulators has not been addressed yet. We used the gold-derivative auranofin to induce cancer cell death by targeting thioredoxin reductases in combination with CyPPA to activate SK channels in neuro- and glioblastoma cells. Combined treatment with auranofin and CyPPA induced massive mitochondrial damage and potentiated auranofin-induced toxicity in neuroblastoma cells in vitro. In particular, mitochondrial integrity, respiration and associated energy generation were impaired. These findings were recapitulated in patient-derived glioblastoma neurospheres yet not observed in non-cancerous HT22 cells. Taken together, integrating auranofin and SK channel openers to affect mitochondrial health was identified as a promising strategy to increase the effectiveness of anti-cancer agents and potentially overcome resistance.
Sujet(s)
Auranofine/pharmacologie , Tumeurs du cerveau/métabolisme , Glioblastome/métabolisme , Neuroblastome/métabolisme , Pyrazoles/pharmacologie , Pyrimidines/pharmacologie , Canaux potassiques calcium-dépendants de petite conductance/agonistes , Animaux , Protocoles de polychimiothérapie antinéoplasique/pharmacologie , Auranofine/administration et posologie , Tumeurs du cerveau/traitement médicamenteux , Tumeurs du cerveau/anatomopathologie , Mort cellulaire/effets des médicaments et des substances chimiques , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Synergie des médicaments , Glioblastome/traitement médicamenteux , Glioblastome/anatomopathologie , Humains , Souris , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/métabolisme , Neuroblastome/traitement médicamenteux , Neuroblastome/anatomopathologie , Pyrazoles/administration et posologie , Pyrimidines/administration et posologie , Canaux potassiques calcium-dépendants de petite conductance/métabolisme , Sphéroïdes de cellules/effets des médicaments et des substances chimiques , Thioredoxin-disulfide reductase/antagonistes et inhibiteurs , Thioredoxin-disulfide reductase/métabolismeRÉSUMÉ
Aspartic acid derivatives with branched N-alkyl or N-arylalkyl substituents are valuable precursors to artificial dipeptide sweeteners such as neotame and advantame. The development of a biocatalyst to synthesize these compounds in a single asymmetric step is an as yet unmet challenge. Reported here is an enantioselective biocatalytic synthesis of various difficult N-substituted aspartic acids, including N-(3,3-dimethylbutyl)-l-aspartic acid and N-[3-(3-hydroxy-4-methoxyphenyl)propyl]-l-aspartic acid, precursors to neotame and advantame, respectively, using an engineered variant of ethylenediamine-N,N'-disuccinic acid (EDDS) lyase from Chelativorans sp. BNC1. This engineered C-N lyase (mutant D290M/Y320M) displayed a remarkable 1140-fold increase in activity for the selective hydroamination of fumarate compared to that of the wild-type enzyme. These results present new opportunities to develop practical multienzymatic processes for the more sustainable and step-economic synthesis of an important class of food additives.