Bioanalytical method for quantitative determination of mithramycin analogs in mouse plasma by HPLC–QTOF

Mithramycin (MTM) has potent anticancer activity, but severe toxicities restrict its clinical use. Semi‐synthetic approaches have yielded novel MTM analogs with potentially lower toxicity and similar efficacy. In an effort to transition these analogs into in vivo models, a bioanalytical method was developed for their quantification in mouse plasma. Here we present the validation of the method for the quantitation of mithramycin SA‐tryptophan (MTMSA‐Trp) as well as the applicability of the methodology for assaying additional analogs, including MTM, mithramycin SK (MTMSK) and mithramycin SA‐phenylalanine (MTMSA‐Phe) with run times of 6 min. Assay linearity ranged from 5 to 100 ng/mL. Accuracies of calibration standards and quality control samples were within 15% of nominal with precision variability of