
A new strategy has been developed to successfully produce the active component danshensu ex vivo. For this purpose, phenylalanine dehydrogenase from Bacillus sphaericus was combined with the novel hydroxyphenylpyruvate reductase from Mentha x piperita, thereby providing an in-situ cofactor regeneration throughout the conversion process. The purified enzymes were co-immobilized and subsequently employed in batch biotransformation, resulting in 60% conversion of 10 mM L-dopa within 24 hours, with a catalytic amount of NAD+ as cofactor. Furthermore, the bienzymatic system was implemented as a packed-bed reactor in continuous flow, achieving a conversion rate up to 80% with 60 minutes retention time. The process was further intensified by implementing a 48-hour flow bioreaction. The biocatalysts demonstrated remarkable stability, retaining 62% of their initial activity at the end of the process. The final productivity of the isolated compound (96% purity) was calculated to be 1.84 g L-1 h-1 yielding a sustainable synthesis of danshensu.
Well done Valentina on bringing home this last trophy!
Read the full paper here