Enzymatic Synthesis of D-D4FC Using Intact Cells / 微生物学通报

ABSTRACT

D-D4FC (?-D-2′,3′-didehydro-2′,3′-dideoxy-5-fluorocytidine),a new anti-HIV drug,is on its PhaseⅡ clinical trials in America,France and Germany. Our lab has synthesized D-D4FC successfully using N-deoxyribosyltransferase from Lactobacillus helveticto catalyzing the ribose transfer from D4T (?-D-2′,3′-unsaturated thymidine) to 5-FC (5-fluorocytidine).The yield of D-D4FC reached 25%.We discovered the reaction could also be done by using intact cells.The yield could increase to 50% in 12.5 hours and more convenient to industrial continuous process.In this paper,the conditions including pH,buffer,substrates concentration,cells amount,reaction time and a possible catalytic mechanism were studied and discussed.