Cofactor-Free, Direct Photoactivation of Enoate Reductases for the Asymmetric Reduction of C=C Bonds.
Angew Chem Int Ed Engl
; 56(30): 8681-8685, 2017 07 17.
Article
em En
| MEDLINE
| ID: mdl-28544039
ABSTRACT
Enoate reductases from the family of old yellow enzymes (OYEs) can catalyze stereoselective trans-hydrogenation of activated C=C bonds. Their application is limited by the necessity for a continuous supply of redox equivalents such as nicotinamide cofactors [NAD(P)H]. Visible light-driven activation of OYEs through NAD(P)H-free, direct transfer of photoexcited electrons from xanthene dyes to the prosthetic flavin moiety is reported. Spectroscopic and electrochemical analyses verified spontaneous association of rose bengal and its derivatives with OYEs. Illumination of a white light-emitting-diode triggered photoreduction of OYEs by xanthene dyes, which facilitated the enantioselective reduction of C=C bonds in the absence of NADH. The photoenzymatic conversion of 2-methylcyclohexenone resulted in enantiopure (ee>99 %) (R)-2-methylcyclohexanone with conversion yields as high as 80-90 %. The turnover frequency was significantly affected by the substitution of halogen atoms in xanthene dyes.
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Coleções:
01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article