| Popis: |
As the third part of our methodology studies on the application of centrifugal counter-current chromatography to the preparative separation of macrolide antibiotic analogues, we have investigated the effects of various parameters on the retention of stationary phase and peak resolution. Our results show that the retention percentage of the stationary phase has linear relationships with both flow-rate at 1 to 3 ml/min and rotation speed at 100 to 700 rpm, but their correlation coefficients are negative (-1.000) and positive (0.9821), respectively. The peak resolution (Rs) is inversely proportional to the flow-rate (Fr) and mass load (Ml), but directly proportional to the rotation speed (Rrev). Their correlation coefficients in linear regression for the preparative separation in laboratory scale are -0.981 to -1.000 for Rs=a+bFr at flow-rates of 1 to 3 ml/min, -0.929 to -0.993 for Rs=a+bMl at mass loads of 12.5 to 100 mg, and 0.975 to 0.998 for Rs=a+bRrev at rotation speeds of 300 to 700 rpm, respectively. Preparative separation of six very closely related macrolide antibiotics, which belong to ascomycin and rapamycin analogues, has also been successfully achieved under optimized conditions. |
Full Text from ScienceDirect