类产碱假单胞菌全细胞催化前手性酮对映选择性还原合成西他列汀手性中间体

以苯乙酮为唯一碳源,从土壤中筛选出一株能够将4-氧-4-3-(三氟甲基)-5,6-二氢1,2,4]三唑并4,3-a]吡嗪-7(8H)-基]-1-(2,4,5-三氟苯基)丁-2-酮(2)对映选择性还原为抗Ⅱ型糖尿病药物西他列汀关键手性中间体(S)-3-羟基-1-3-(三氟甲基)-5,6-二氢1,2,4]三唑并4,3-a]吡嗪-7(8H)-基]-4-(2,4,5-,三氟苯基)丁-1-酮((S)-1)的细菌菌株,经鉴定并命名为类产碱假单胞菌(Pseudomonas pseudoalcaligenes)XW-40.系统研究了水溶性辅溶剂、温度、p H、底物浓度、细胞浓度、反应时间等反应条件对生物还原产率和对映选择性的影响.该菌株全细胞能够耐受浓度高达10 g/L的前手性酮2.在最优反应条件下,以制备规模合成了(S)-1,分离收率90%,ee99%.

Highly enantioselective bioreduction of prochiral ketone to a chiral intermediate of sitagliptin by whole cells of Pseudomonas pseudoalcaligenes XW-40

ABSTRACT: A bacterial strain isolated from soil with acetophenone as the sole carbon source, identified by 16r sDNA and designated as Pseudomonas pseudoalcaligenes XW-40, is capable of reducing enantioselectively 4-oxo-4-3-(trifluoromethyl) -5,6-dihydro-1,2,4]triazolo4,3-a]pyraz in-7(8H)-yl)-1-(2,4,5-trifluorophenly)butan-2-one(2) to (S) -3-hydroxy-1-(3-(trifluoromethyl)-5,6- dihydro1,2,4]triazolo4,3-a]pyrazin-7(8H)-yl]-4-(2,4,5-trifl-uorophenyl)butan-1-one(1), a chiral intermediate for the production of sitagliptin. The effects of bioreduction conditions such as water-soluble cosolvents, temperature, pH, substrate concentration, cell concentration and reaction time on the conversion and enantioselectivity were studied. The whole cells of Pseudomonas pseudoalcaligenes XW-40 is tolerant towards prochiral ketone 2 at concentration as high as 10g/L. Under the optimal conditions, the preparative-scale reaction yielded (S)-1 in 90% isolated yield and >99% ee.