4. Discussion
The current research hotspot is to modify the structure of RA to obtain
drugs with superior efficacy. We prepared N-substituted RA compounds and
completed a preliminary pharmacodynamic evaluation. To clarify the
mechanisms of A1, pharmacokinetic studies of A1 and RA are required. In
this study, a sensitive, simple and rapid HPLC–MS/MS method was adopted
to simultaneously analyze A1 and RA in a single-dose study on rat
plasma. It has been successfully applied to the PK study of RA and A1 in
rats. This result may provide a reference for the modification of the RA
structure.