摘要
研究了用固定化赭曲霉(Aspergillus ochraceus)、淡紫色犁头霉(Absidiasp.A28)双霉协同生物转化C21甾苷元的C11α-羟基化的条件。确定优化的细胞固定化条件为:4%的海藻酸钠包埋15%的湿菌体,在4%的氯化钙溶液中固定化1 h;优化的羟基化转化条件为:固定化菌体的最佳培养周期为48 h、甾苷元浓度为9 g.L-1、pH值为8.0、转化温度为28℃。连续转化3批,转化率均超过88.5%。转化获得的C11α-羟基化甾苷元粗品经乙酸乙酯提取分离,3次重结晶后,采用质谱、核磁共振、元素分析等手段进行结构表征。确认所制备的物质为C11α-羟基化甾苷元,其熔点为240℃,纯度为99.7%,呈浅黄色,表面光滑,在乙酸乙酯中的比旋光度为-12.6°(25℃)。
The conditions of C11α-hydroxylation of C21 steroidal aglycones had been studied by the synergistic bio-transformation of immobilized Aspergillus ochraceus and Absidia sp.A28.The results showed that the optimal transformational conditions of C11α-hydroxylation were as follows： the wet cells of 15% in sodium alginate of 4% were immobilized by calcium chloride of 4% for 1 h,the cycle of culture was 48 h,steroidal aglycones concentration was 9 g·L-1,pH value was 6.0,temperature was 28℃.The experiments were repeated thrice as above,and all of the conversion rates exceeded 88.5%.The crude products were extracted by ethyl acetate.The products purified by recrystallization thrice were determined as C11α-hydroxylated steroidal aglycones by mass spectroscopy,nuclear magnetic resonance spectroscopy,and elemental analysis,etc.The results showed that the purity of C11α-hydroxylated steroidal aglycones was 99.8%.The crystals of C11α-hydroxylated steroidal aglycones were light yellow and smooth with m.p.of 240℃ and ／25D of-12.6°（in ethyl acetate）.
出处
《化学与生物工程》
CAS
2009年第12期66-69,共4页
Chemistry & Bioengineering
关键词
固定化
C11α-羟基化
赭曲霉
犁头霉
immobilization C11α-hydroxylation Aspergillus ochraceus Absidia sp.
