Stereo-Inversion in the (4R)-γ-Decanolactone Synthesis by Saccharomyces cerevisiae: (2E,4S)-4-Hydroxydec-2-enoic Acid Acts as a Key Intermediate
作者:Gunnar Köhler、Paul Evans、Leif-Alexander Garbe
DOI:10.1002/hlca.201100280
日期:2011.12
erythro‐3,4‐dihydroxydecanoic acid and erythro‐3‐hydroxy‐γ‐decanolactone from methyl (2E,4S)‐4‐hydroxydec‐2‐enoate supports a net inversion to (4R)‐γ‐decanolactone via 4‐oxodecanoic acid. As postulated in a previous work, (2E,4S)‐4‐hydroxydec‐2‐enoic acid was shown to be a key intermediate during (4R)‐γ‐decanolactone formation via degradation of (3S,4S)‐dihydroxy fatty acids and precursors by Saccharomyces
(2 E,4 R)-4-羟基癸-2-烯酸甲酯,(2 E,4 S)-4-羟基癸-2-烯酸甲酯和(±)-(2 E)-4-羟基癸酸乙酯[4 ‐ 2 H] dec-2-烯酸酯是化学合成的,并在酿酒酵母中孵育。观察到这些底物的最初C链伸长至C 12,并在较小程度上观察到C 14脂肪酸,随后形成γ-癸内酯。(2 E,4 R)-4-羟基癸-2-烯酸甲酯和(2 E,4 S)-4-羟基癸-2-烯酸甲酯的代谢转化均导致(4 R)γ-癸醇内酯的ee分别> 99%和ee达到80%。乙基的生物转化(±) - (2 ë)-4-羟基(4- 2 2H)癸-2-烯酸甲酯,得到(4 - [R )- γ - [ 2 H]癸与61%2 ħ标签保持和90%ee表明存在立体倒置途径。4-羟基癸酸的电子冲击质谱分析(图4)显示出C(4)→C(2)2 H的部分位移。的形成赤-3,4- dihydroxydecanoic酸和赤-3-羟基γ