In this work six kinds of tartrate diesters were prepared from D(-), L(+) or DL-tartaric acid respectively, and their structure were verified by IR and NMR. The extraction behavior of optical compounds, D(-) ephedrine...In this work six kinds of tartrate diesters were prepared from D(-), L(+) or DL-tartaric acid respectively, and their structure were verified by IR and NMR. The extraction behavior of optical compounds, D(-) ephedrine and L(+) pseudoephedrine, was investigated at room temperature using prepared tartrate diester as extracting agent and n -heptane as diluent. The ratio of tartrate diester and n -heptane is 1∶1. Distribution coefficients, obtained from experiment data by material balance, show that there is a chiral recognition: L(+) tartrate diesters favour extraction of L(+) pseudoephedrine,while D(-) tartrate diesters favour extraction of D(-) ephedrine. The extraction behavior of the mixture of the above optical active epimerides, was also investigated under the same experimental conditions. The experiment data with HPLC also showed the same conclusion. Meanwhile, a blank experiment was carried out and the result showed that there was no evident effect on extraction distribution coefficients when extraction process occurred in the presence of n -heptane. The relationship between the structure of extracting agent and optical activity of the epimerides was also discussed.展开更多
In batch cultures of Candida krusei , the effect of corn steep liquor (CSL) concentration was investigated. The result showed that glycerol yield was greatly affected by CSL concentration. Higher glycerol yield was at...In batch cultures of Candida krusei , the effect of corn steep liquor (CSL) concentration was investigated. The result showed that glycerol yield was greatly affected by CSL concentration. Higher glycerol yield was attained when the initial CSL concentration in the medium was 9?g·L -1 . The fermentation kinetics were studied and the parameters for cell growth, maintenance, and glycerol production were obtained. Material balance revealed by product formation during the growth phase and suggested a fed-batch culture strategy.展开更多
文摘In this work six kinds of tartrate diesters were prepared from D(-), L(+) or DL-tartaric acid respectively, and their structure were verified by IR and NMR. The extraction behavior of optical compounds, D(-) ephedrine and L(+) pseudoephedrine, was investigated at room temperature using prepared tartrate diester as extracting agent and n -heptane as diluent. The ratio of tartrate diester and n -heptane is 1∶1. Distribution coefficients, obtained from experiment data by material balance, show that there is a chiral recognition: L(+) tartrate diesters favour extraction of L(+) pseudoephedrine,while D(-) tartrate diesters favour extraction of D(-) ephedrine. The extraction behavior of the mixture of the above optical active epimerides, was also investigated under the same experimental conditions. The experiment data with HPLC also showed the same conclusion. Meanwhile, a blank experiment was carried out and the result showed that there was no evident effect on extraction distribution coefficients when extraction process occurred in the presence of n -heptane. The relationship between the structure of extracting agent and optical activity of the epimerides was also discussed.
文摘In batch cultures of Candida krusei , the effect of corn steep liquor (CSL) concentration was investigated. The result showed that glycerol yield was greatly affected by CSL concentration. Higher glycerol yield was attained when the initial CSL concentration in the medium was 9?g·L -1 . The fermentation kinetics were studied and the parameters for cell growth, maintenance, and glycerol production were obtained. Material balance revealed by product formation during the growth phase and suggested a fed-batch culture strategy.