A subnanogram API LC/MS/MS quantitation method for depsipeptide FR901228 and its preclinical pharmacokinetics

J Pharm Biomed Anal. 2000 Feb;22(1):33-44. doi: 10.1016/s0731-7085(99)00243-5.


A highly sensitive and specific atmospheric pressure ionization (API) liquid chromatographic-tandem mass spectrometric (LC/MS/MS) method for the quantitation of depsipeptide FR901228 (NSC-630176, FR), a naturally occurring antitumor agent, was developed and validated. FR was extracted from human or rat plasma along with the internal standard, t-Boc-Met-Leu-Phe (BMLP) with ethyl acetate. Components in the extract were separated on a 5-microm C8 Spherisorb 50 x 4.6 mm i.d. column by isocratic elution with methanol/acetonitrile/12 mM ammonium acetate (60:10:30, v/v/v). The liquid flow was passed through a presource splitter and 5% of the eluate was introduced into the API source. The components were analyzed in the multiple-reaction monitoring (MRM) mode to enhance specificity. Linear calibration curves were obtained in the range of 0.1-100.0 ng/ml with 0.5 ml human plasma and 0.5-100.0 ng/ml with 0.1 ml rat plasma. The limit of quantitation (LOQ) was 0.1 ng/ml using 0.5 ml human plasma and 0.5 ng/ml using 0.1 ml rat plasma. The overall within-day precision was below 12% in human plasma and below 7% in rat plasma; and the between-day precision was below 10.2% in human plasma and 7.2% in rat plasma. The accuracy at low, medium and high levels ranged from 99.3 to 111.7% in human plasma and 96.2-107.3% in rat plasma. The high sensitivity permitted pharmacokinetic study of FR in the rat at a single i.v. dose as low as 1 mg/kg. At this dose, plasma FR levels declined biexponentially with a mean terminal t(1/2) of 187.7 min (n = 6) and were detectable up to 24 h. After an oral dose at 5 mg/kg, plasma FR levels were highly erratic and yielded a mean bioavailability of 1.6% (n = 6). At a higher oral dose of 50 mg/kg, a mean bioavailability of 10.6% was obtained, both being estimated by a non-crossover method.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Oral
  • Animals
  • Anti-Bacterial Agents / analysis*
  • Anti-Bacterial Agents / pharmacokinetics*
  • Antibiotics, Antineoplastic / analysis*
  • Antibiotics, Antineoplastic / pharmacokinetics*
  • Area Under Curve
  • Chromatography, Liquid
  • Depsipeptides*
  • Humans
  • Injections, Intravenous
  • Male
  • Peptides, Cyclic*
  • Rats
  • Rats, Sprague-Dawley
  • Reproducibility of Results


  • Anti-Bacterial Agents
  • Antibiotics, Antineoplastic
  • Depsipeptides
  • Peptides, Cyclic
  • romidepsin