【作者】 杨晨茹；

【导师】 高锦明；

【作者基本信息】 西北农林科技大学 ， 化学生物学， 2012， 硕士

【摘要】 微生物转化是天然产物结构修饰非常有用的工具。它能够催化化合物中的不活泼碳原子，进行区域选择性和立体选择性反应，使得很多通过有机合成手段难以完成的反应迅速、顺利进行。所以，微生物转化已经成为一项可靠高效的手段来进行药物衍生物的合成。甾体类药物是目前继抗生素之后人类使用的第二大类药物，广泛的用于抗炎、利尿、孕激素、蛋白同化剂、肿瘤抑制剂等。孕甾三醇是剑麻皂苷元的水解产物，合理的利用孕甾三醇，将其转化成为医药、农药及有潜在用途的化合物，不仅可以寻找新的具有药理活性的衍生物，而且可达到进一步利用剑麻皂苷元的目的。本文运用微生物转化的手段对孕甾三醇进行结构修饰，分离鉴定了5个转化产物。主要结果如下：从十一株真菌中筛选出四株具有转化孕甾三醇能力的真菌，包括白腐真菌(Coriolusversicolor)、短刺小克银汉霉(Cunnonghamella blakesleeana)、雅致小克银汉霉(Cunnonghamella elegans)、刺孢小克银汉霉(Cunnonghamella echinulata)。最终选择刺孢小克银汉霉(Cunninghamella echinulata)作为转化菌株，经活化后加入底物pregnane-3β,16β,20-triol并进行扩大培养。借助正相柱层析、反相RP-18柱层析、SephadexLH-20等分离手段，从乙酸乙酯浸膏中分离得到6个转化产物，结合1D和2D NMR波谱技术、高分辨质谱等方法分别鉴定5个单体化合物：孕甾-3β,14α,16β,20-四醇(YZIII-1)，孕甾-3-羰基-14α,16β,20-三醇(YZIII-2)，孕甾-3-羰基-7β,16β,20-三醇(YZIII-3)，孕甾-3β,7β,16β,20-四醇(YZIV-4)，孕甾-3β,5,16β,20-四醇(YZIV-5)。这五个化合物均为新的孕甾三醇的衍生物。更多还原

【Abstract】 Microbial transformation has been proven to be a useful addition to technology. Inertcarbon in a series of compounds could be catalyzed with the hydroxyl by the regioselectiveand stereo-selectivity synthesis of the technique and some complex organic reactions may beextremely specific and quickly completed. In addition, microorganisms can be used as areliable and efficient synthetic chemistry for obtaining sizable amounts of a number of drugderivativesSteroidal drugs are the second largest category of drugs only lower than antibiotics. Avariety of steroids are widely used as anti-inflammatory, diuretic, anabolic, contraceptive, andanticancer agents as well as in other applications. The effective method of direct oxidativedegradation of tigogenin into pregnane-3β,16β,20-triol has been developed. In order toconvert pregnane-3β,16β,20-triol into medicine and potentially useful organic molecules andthen applied to synthesize steroidal drugs, synthetic intermediates or natural steroids withimportant physiological activity, and further to utilize tigogenin rationally.In this article, the way which use biotransformation to modify the structure ofpregnane-3β,16β,20-triol by introducing the hydroxyl. The main contents and results areconcluded as follow:Screening scale experiments showed that Coriolus versicolor, Cunnonghamellablakesleeana, Cunnonghamella elegans and Cunnonghamella echinulata which are screenedfrom eleven microorganisms, have abilities to transform pregnane-3β,16β,20-triol into itsderivatives as determined by TLC. Cunninghamella echinulata had been selected astransforming bacteria form eleven test epiphytes and been used for a large scale liquidfermentation. Incubation of substrate pregnane-3β,16β,20-triol with Cunninghamellaechinulata yielded six major metabolites by multiple column chromatography on CC, ODS,Sephadex LH-20,et al., five of which were identified by various spectroscopic methods (1DNMR,2D NMR) in combination with HR-MS, MS and IR as pregnane-3β,14α,16β,20-tetrol(YZIII-1), pregnane-3-oxo-14α,16β,20-triol (YZIII-2), pregnane-3-oxo-7β,16β,20-triol(YZIII-3), pregnane-3β,7β,16β,20-tetrol (YZIV-4), and pregnane-3β,5,16β,20-tetrol (YZIV-5).These five metabolites were also new bioconversion products.更多还原