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Claisen-tipo de adición de glicina a piridoxal en el agua
Krisztina Toth1, Tina L Amyes, John P Richard
1Department of Chemistry, University at Buffalo, SUNY, Buffalo, New York 14260-3000, USA.
Journal of the American Chemical Society
|August 26, 2004
Resumen
La química del piridoxal produjo inesperadamente productos de adición del tipo Claisen, no transaminación ni intercambio de deuterio. Esto pone de relieve la reactividad selectiva del enolato de glicina estabilizado con 5'-deoxipiridoxal en agua.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Química orgánica es la química orgánica.
- Catalización de enzimas por catalización de enzimas
Sus antecedentes:
- El piridoxal es un cofactor crucial en las reacciones de transaminación biológica.
- La glicina es el aminoácido más simple, a menudo involucrado en procesos enzimáticos.
- El intercambio de deuterio puede sondear los mecanismos de reacción y la movilidad de los protones.
Objetivo del estudio:
- Para investigar los productos de reacción de 5 acut{}-deoxypyridoxal y glicina en agua deuterada.
- Para determinar si se produce la transaminación catalizada por piridoxal o el intercambio de deuterio.
- Para entender la reactividad inesperada observada.
Principales métodos:
- Reacción del 5-deoxipiridoxal agudo con la glicina en D2O.
- Control de la pD en el punto 7.0.
- Análisis de los productos de reacción.
Principales resultados:
- No se observó ninguna transaminación significativa ni intercambio de deuterio.
- Rendimiento cuantitativo de dos productos diastereoméricos de una adición de tipo Claisen.
- El enolato de glicina se agrega selectivamente al grupo carbonilo de 5 agudos-deoxipiridoxal.
Conclusiones:
- La reacción favorece la adición de tipo Claisen sobre la química esperada de piridoxal.
- El enolato de glicina estabilizado con desoxipiridoxal agudo 5 exhibe una alta selectividad para la adición de carbonilo en el agua.
- Este hallazgo ofrece nuevos conocimientos sobre la reactividad de los derivados de piridoxal.
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