假单胞菌催化的碳碳双键不对称还原

Asymmetric reduction of C=C bond catalyzed with Pseudomonas species

烯醇还原酶能够催化活性烯烃的不对称还原,得到具有一个或两个手性中心的烷烃化合物.为了挖掘含有烯醇还原酶的微生物资源,本研究利用柠檬醛与(Z)-乙基-3-硝基-2-苯基丙烯酸酯对土壤中的细菌进行富集筛选与鉴定,得到7株具有碳碳双键还原活力的假单胞菌.利用全细胞生物转化体系,分别研究这7株菌株对8种不同底物的转化活力,结果显示上述菌株表现出不同的底物偏好性、对映选择性以及结构选择性.例如菌株7-B-2能够以99%的转化率和e.e.值将底物(Z)-乙基-3-硝基-2-苯基丙烯酸酯转化为(S)-乙基-3-硝基-2-苯基丙酸酯;菌株9-A-1能够以75%的转化率和99%的e.e.值将底物(Z)-3-苯基-3-氰基-丙烯酸转化为(R)-3-苯基-3-氰基-丙酸.研究结果表明这7个菌株在重要手性中间体的生物合成中具有一定研究与应用价值.

Asymmetric reduction of activated alkenes to the corresponding enantiopure alkanes by enoate reductases（ERs） can lead to one or two chiral centers. In the present work, citral and（Z）-ethyl 3-nitro-2-phenylacrylate were used to enrich and screen microbes producing ERs from soil. Seven microbial strains were obtained and identified as Pseudomonas sp., which displayed varied substrate preference and enantio-selectivity toward eight activated alkenes or alkynes. Strain 7-B-2 could transform（Z）-ethyl 3-nitro-2-phenylacrylate to（S）-ethyl 3-nitro-2-phenylpropanoate with a conversion and e.e. value of 99%; strain 9-A-1 could transform（Z）-3-cyano-3-phenylacrylic acid to（R）-3-cyano-3-phenylpropanoic acid with a conversion of 75% and e.e. value of 99%. The results demonstrated that the strains from the genus of Pseudomonas are important to bioreductive synthesis of some important chiral intermediates.