Adenine → Vidarabine

Participants

Reaction Conditions

Reaction Steps

50 kg of wet cell paste obtained by fermenting E. aerogenes were resuspended in approximately 200 liters of 30 mM phosphate buffer at pH 7 and mixed with 800 liters of phosphate buffer in which had been dissolved at elevated temperature 5.4 kg of adenine (final concentration 40 mM) and 8.9 kg of Ara-U (final concentration 40 mM). The mixture was maintained at 60° C., with agitation, for 20 hours, diluted to approximately 3000 liters with hot H2O and subjected to diafiltration on a membrane, collecting approximately 5000 liters of ultrafiltrate. The bioconversion yield determined by RP-HPLC was approximately 55%. The residue containing the cell paste is used for a subsequent reaction. The ultrafiltrate was concentrated to approximately 1000 liters and cooled to collect the precipitate constituted by Ara-A contaminated with non-reacted adenine (approximately 30 g of adenine per 100 g of Ara-A). 5 kg of Ara-A (total yield approximately 46%) with a degree of purity higher than 99.5% were finally obtained after crystallisation with H2O.

Provenance & Evidence