Enzymatic Synthesis of D-D4FC Using Intact Cells

Abstract:

D-D4FC (β-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 (β-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.