Sequential Enzymatic Conversion of ?-Angelica Lactone to ?-Valerolactone through Hydride-Independent C=C Bond Isomerization.

ABSTRACT: A case of hydride-independent reaction catalyzed by flavin-dependent ene-reductases from the Old Yellow Enzyme (OYE) family was identified. ?-Angelica lactone was isomerized to the conjugated ?-isomer in a nicotinamide-free and hydride-independent process. The catalytic cycle of C=C bond isomerization appears to be flavin-independent and to rely solely on a deprotonation-reprotonation sequence through acid-base catalysis. Key residues in the enzyme active site were mutated and provided insight on important mechanistic features. The isomerization of ?-angelica lactone by OYE2 in aqueous buffer furnished 6.3?mm ?-isomer in 15?min at 30?°C. In presence of nicotinamide adenine dinucleotide (NADH), the latter could be further reduced to ?-valerolactone. This enzymatic tool was successfully applied on semi-preparative scale and constitutes a sustainable process for the valorization of platform chemicals from renewable resources.

SUBMITTER: Turrini NG 

PROVIDER: S-EPMC5574032 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature