Stability Study, Quantification Method and Pharmacokinetics Investigation of a Coumarin-Monoterpene Conjugate Possessing Antiviral Properties against Respiratory Syncytial Virus.

The stability of a new coumarin derivative, agent K-142, bearing α-pinene residue and possessing antiviral activity against respiratory syncytial virus (RSV) was studied in whole mice blood in vitro, and a method for its quantification in this matrix was developed and validated. The sample preparation method was precipitation of whole blood with a mixture of 0.2 M ZnSO4 with MeOH (2:8 v/v) containing 2-adamantylamine hydrochloride as an internal standard (IS). Analysis was carried out by HPLC-MS/MS using reversed phase chromatography and a triple quadrupole mass spectrometer 6500 QTRAP (SCIEX) in multiple reaction monitoring (MRM) mode. The transitions 351.2 → 217.1 Da and 152.2 → 93.1/107.2 Da were monitored for K-142 and the IS, respectively. The method was validated in terms of selectivity, calibration curve, LLOQ, accuracy and precision, stability, recovery and carry over. The developed method was used for a pharmacokinetics study of the compound after its oral administration to mice at a dose of 20 mg/kg.

Untargeted search and identification of metabolites of antiviral agent camphecene in rat urine by liquid chromatography and mass spectrometry and studying their distribution in organs following peroral administration of the compound.

Major metabolites of camphecene, a new effective antiviral agent, formed after its oral administration to rats and excreted in the urine, were found and identified using liquid chromatography coupled to mass spectrometry as well as multivariate analysis of HPLC-MS data. The metabolites were found to be camphecene glucuronide, camphecene sulfate and the corresponding iminoacid. A study of the dynamics of accumulation of camphecene and its metabolites in the liver, kidneys, lungs and brain of animals was performed. Maximum concentration of camphecene in blood and organs was reached after 1.5-2 h of its administration, and the maximal content of the agent in the organs investigated was observed in the kidneys. The content of the substance in the lungs was comparable to that in the liver. Also, camphecene was found in brain in high concentration, thus allowing assumption of its ability to penetrate the blood-brain barrier and to exert its antiviral properties in the organ. Camphecene glucuronide and iminoacid had concentration-time profiles similar to that of their precursor, their content being maximal in kidney and liver and 2-3 orders of magnitude higher than in lungs and brain. The content of camphecene sulfate was of similar level in all organs studied. The results obtained made it possible to develop recommendations for therapy with the use of camphecene.