research Structural characterization of cyclosporin A, C and microbial bio-transformed cyclosporin A analog AM6 using HPLC–ESI–ion trap-mass spectrometry
This study developed an advanced HPLC-ESI-ion trap MS(n) method for the structural identification of cyclosporin A analogs CyA and CyC and reported the first MS(n)-aided identification of a new CyA analog.