微生物转化法合成3-氧代齐墩果酸及其条件优化

Synthesis of 3-Oxo-oleanolic Acid by Microbial Transformation and Optimization of Transformation Conditions

以齐墩果酸为底物,选取雷斯青霉(Penicilliumraistrickii)、赭曲霉(Aspergillus ochraceus)和黑根霉(Rhi-zopus nigricans)三种微生物对其进行转化,采用TLC、HPLC方法检测转化产物。结果表明,雷斯青霉和赭曲霉对齐墩果酸有转化能力,其中雷斯青霉转化能力较高,主产物为3-氧代齐墩果酸;对雷斯青霉生物转化条件进行优化,确定最佳工艺条件为:投料时间36 h、转化时间48 h、转化pH值5.5、转化温度28℃、最大底物加入量不超过100 mg.L-1、DMF体积分数0.6%。在此条件下,齐墩果酸转化率可达7.95%、3-氧代齐墩果酸生成率达50.97%。用雷斯青霉对齐墩果酸进行衍生化,是一种合成3-氧代齐墩果酸新方法。

Microbial transformation of oleanolic acid（OA） was performed by Penicillium raistrickii, Aspergillus ochraceus and Rhizopus nigricans. The original substrates and their metabolites were analyzed with TLC and HPLC. The both P. raistrickii and A. ochraceus showed biocatalytic capability to metabolize OA, for the more, P. raistrickii exhibited the relative higher ability to produce 3-oxo-oleanolic acid（3-oxo-OA）. The optimized transformation process with P. raistrickii were as follows： the microorganism cultivating cost 36 h at 28℃ ; pH value was adjusted to 5.5 before the substrate addition; the addition amount of substrate was less than 100 mg·L^-1 ; co-solvent was DMF （0.6%, volume fraction） ; biotransformation time was 48 h. Under above conditions,the conversion rate of OA was 7.95% and the yield of 3-oxo-OA was 50.97%. 3-Oxo-OA was synthesized with a novel method of biotransformation of OA by Penicillium raistrickii.