Biocatalytic access to betazole using a one-pot multienzymatic system in continuous flow

As an alternative to classical synthetic approaches for the production of betazole drug, a one-pot biocatalytic system for this pharmaceutical molecule from its alcohol precursor has been developed. An omega-transaminase, an alcohol dehydrogenase and a water-forming NADH oxidase for in situ cofactor recycling have been combined to catalyse this reaction, yielding 75% molar conversion in batch reactions with soluble enzymes. This multienzyme system was then co-immobilised through a newly established protocol for sequential functionalization of a methacrylate-based porous carrier to enable tailored immobilisation chemistries for each enzyme. This pluri-catalytic system has been set up in a continuous flow packed-bed reactor, generating a space-time yield of up to 2.59 g L-1 h(-1) with 15 min residence and a constant supply of oxygen for in situ cofactor recycling through a segmented air-liquid flow. The addition of an in-line catch-and-release column afforded >80% product recovery.

Automated summary

A one-pot biocatalytic system has been developed for the production of betazole drug, achieving a 75% molar conversion rate. By immobilizing a multienzyme system in a continuous flow packed-bed reactor, a yield of up to 2.59 g L-1 h(-1) has been achieved with over 80% product recovery.