A screening of non-conventional yeast species and several Saccharomyces cerevisiae (baker's yeast) strains overexpressing known carbonyl reductases revealed the S. cerevisiae reductase encoded by YMR226c as highly efficient for the reduction of the diketones 1 and 2 to their corresponding hydroxyketones 3–6 (Scheme 1) in excellent enantiomeric excesses. Bioreduction of 1 using the genetically engineered yeast TMB4100, overexpressing YMR226c, resulted in >99% ee for hydroxyketone (+)-4 and 84–98% ee for (−)-3, depending on the degree of conversion. Baker's yeast reduction of diketone 2 resulted in >98% ee for the hydroxyketones (+)-5 and (+)-6. However, TMB4100 led to significantly higher conversion rates (over 40 fold faster) and also a minor improvement of the enantiomeric excesses (>99%).
通过对非常规酵母菌种和几种过表达已知羰基还原酶的酿酒酵母(面包酵母)菌株进行筛选,发现 YM
R226c 编码的酿酒酵母还原酶能高效地将二酮 1 和 2 还原成相应的羟基酮 3-6(方案 1),对映体过量。使用过表达 YM
R226c 的
基因工程酵母
TMB4100 对 1 进行
生物还原,根据转化程度的不同,羟基酮 (+)-4 的eee>99%,(-)-3 的eee为 84-98%。贝克酵母还原二酮 2 可使羟基酮 (+)-5 和 (+)-6 的ee值大于 98%。不过,
TMB4100 的转化率明显更高(快了 40 多倍),对映体过剩率也略有提高(>99%)。