The reduction of geraniol to citronellol is the first step for the synthesis of natural phytol in the production of tocopherols and natural vitamin K.Baker's yeast was used in the bioreduction described above as a...The reduction of geraniol to citronellol is the first step for the synthesis of natural phytol in the production of tocopherols and natural vitamin K.Baker's yeast was used in the bioreduction described above as a whole-cell biocatalyst.However,the enzyme responsible for the reduction of geraniol to citronellol is not yet known.Four old yellow enzyme(OYE)genes were cloned from yeast and plants,and expressed in Escherichia coli for a high level of recombinant proteins.The recombinant protein displayed a catalytic activity of converting geraniol to citronellol as a sole product verified by GC-MS analyses.The recombinant OYE2 intact cells were found to show 3.7 and 1.9-fold higher activity than that of yeast cells and the recombinant crude extracts,respectively.Compared to the recombinant fusion enzyme,the entrokinase-cleaved enzyme displayed nearly identical activity for geraniol reduction.To our knowledge,this is the first enzyme identified to catalyze the formation of citronellol from geraniol by reducing the allylic alcohol double bond,which is normally known as inactivating group for the old yellow enzymes.展开更多
文章建立了一种高效液相色谱方法对精油中常见的三种单萜化合物橙花醇、芳樟醇、香茅醇进行定性和定量分析,并进行了方法学验证。得到最佳色谱条件为:C18柱(4.6 mm i.d.×150 mm,5μm),以乙腈∶水=1∶1(v/v)为流动相,流速为1.0 m L/...文章建立了一种高效液相色谱方法对精油中常见的三种单萜化合物橙花醇、芳樟醇、香茅醇进行定性和定量分析,并进行了方法学验证。得到最佳色谱条件为:C18柱(4.6 mm i.d.×150 mm,5μm),以乙腈∶水=1∶1(v/v)为流动相,流速为1.0 m L/min,UV检测波长205 nm。同时验证了其精密度及方法的稳定性。结果表明,该方法灵敏度高,重复性好,方法学验证符合要求。进而采用此方法分析了玫瑰精油、柠檬精油、玫瑰香精、柠檬香精中三种单萜化合物的含量。展开更多
基金This work was supported by grants from the Ministry of Science and Technology of China(2007CB108802)State Key Laboratory of Phytochemistry and Plant Resources in West China(P2008-ZZ16,P2009-ZZ02).
文摘The reduction of geraniol to citronellol is the first step for the synthesis of natural phytol in the production of tocopherols and natural vitamin K.Baker's yeast was used in the bioreduction described above as a whole-cell biocatalyst.However,the enzyme responsible for the reduction of geraniol to citronellol is not yet known.Four old yellow enzyme(OYE)genes were cloned from yeast and plants,and expressed in Escherichia coli for a high level of recombinant proteins.The recombinant protein displayed a catalytic activity of converting geraniol to citronellol as a sole product verified by GC-MS analyses.The recombinant OYE2 intact cells were found to show 3.7 and 1.9-fold higher activity than that of yeast cells and the recombinant crude extracts,respectively.Compared to the recombinant fusion enzyme,the entrokinase-cleaved enzyme displayed nearly identical activity for geraniol reduction.To our knowledge,this is the first enzyme identified to catalyze the formation of citronellol from geraniol by reducing the allylic alcohol double bond,which is normally known as inactivating group for the old yellow enzymes.
文摘文章建立了一种高效液相色谱方法对精油中常见的三种单萜化合物橙花醇、芳樟醇、香茅醇进行定性和定量分析,并进行了方法学验证。得到最佳色谱条件为:C18柱(4.6 mm i.d.×150 mm,5μm),以乙腈∶水=1∶1(v/v)为流动相,流速为1.0 m L/min,UV检测波长205 nm。同时验证了其精密度及方法的稳定性。结果表明,该方法灵敏度高,重复性好,方法学验证符合要求。进而采用此方法分析了玫瑰精油、柠檬精油、玫瑰香精、柠檬香精中三种单萜化合物的含量。
