Huang Haihua, Yang Xiuwei, Li Qiang, Sun Lu, Zhong Dafang
Center for Drug Metabolism Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 646 Songtao Road, Zhangjiang Hi-Tech Park, Shanghai 201203,, People's Republic of China.
Appl Microbiol Biotechnol. 2006 Sep;72(3):486-91. doi: 10.1007/s00253-005-0301-6. Epub 2006 Feb 22.
The hypoglycemic drug tolbutamide is commonly used as a probe drug to evaluate CYP2C9 enzyme activity in terms of production of 4'-hydroxytolbutamide. In the present study, an initial screening of seven filamentous fungi was carried out to identify which was most competent to transform tolbutamide into 4'-hydroxytolbutamide. From this screening, the fungus Cunninghamella blakesleeana AS 3.910 was selected as a suitable bioconverter. At a concentration of 1.2 mg ml(-1), the growing fungus transformed 95.0% of tolbutamide into 4'-hydroxytolbutamide in 96 h. With resting culture, the yield could reach 91.7% and exceeded 91.0% even when the tolbutamide concentration was increased to 4.0 mg ml(-1). On scale-up to 3 l buffer containing 12.0 g tolbutamide, 90% of tolbutamide was transformed into 4'-hydroxytolbutamide in 96 h. Work-up of the broth by column chromatography and recrystallization yielded 6.5 g (53.9% recovered) of 4'-hydroxytolbutamide with a purity of more than 99%. These results suggest C. blakesleeana AS 3.910 is a useful biosynthetic tool in the preparation of 4'-hydroxytolbutamide.
降糖药物甲苯磺丁脲通常用作探针药物，通过4'-羟基甲苯磺丁脲的生成来评估CYP2C9酶的活性。在本研究中，对7种丝状真菌进行了初步筛选，以确定哪种真菌最有能力将甲苯磺丁脲转化为4'-羟基甲苯磺丁脲。通过该筛选，选出了真菌布氏小克银汉霉AS 3.910作为合适的生物转化剂。在浓度为1.2 mg ml(-1)时，生长的真菌在96小时内将95.0%的甲苯磺丁脲转化为4'-羟基甲苯磺丁脲。对于静止培养，即使将甲苯磺丁脲浓度提高到4.0 mg ml(-1)，产率仍可达到91.7%且超过91.0%。扩大规模至含有12.0 g甲苯磺丁脲的3 l缓冲液时，90%的甲苯磺丁脲在96小时内转化为4'-羟基甲苯磺丁脲。通过柱色谱和重结晶对发酵液进行后处理，得到6.5 g（回收率53.9%）纯度超过99%的4'-羟基甲苯磺丁脲。这些结果表明，布氏小克银汉霉AS 3.910是制备4'-羟基甲苯磺丁脲的一种有用的生物合成工具。
