Quantitative analysis of 23‐hydroxybetulinic acid in mouse plasma using electrospray liquid chromatography/mass spectrometry

Abstract

23-Hydroxybetulinic acid is a newly isolated derivative of betulinic acid. The agent exhibits potential anti-tumor activity and functions in this regard via apoptosis. In support of pharmacokinetic and toxicological evaluations, a new assay based on liquid chromatography/mass spectrometry (LC/MS) was developed for the quantitative analysis of 23-hydroxybetulinic acid. Sample preparation consisted of extraction of the plasma by the addition of methylene chloride followed by centrifugation. Aliquots of the supernatant were analyzed using an isocratic reversed-phase high-performance liquid chromatography (HPLC) system coupled to a negative ion electrospray mass spectrometer. Molecules of 23-hydroxybetulinic acid and the internal standard limonin were detected using selected ion monitoring at m/z 471 and 469, respectively. The limit of detection of 23-hydroxybetulinic acid was 0.05 pg (0.11 fmol) injected on-column (10 pg/mL, 5 microL injection volume), and the limit of quantitation was 10 pg (21.19 fmol, 2 ng/mL, 5 muL injection volume). 23-Hydroxybetulinic acid was stable in plasma samples at -20 degrees C for at least 3 weeks. The intra-day and inter-day coefficients of variation of the assay were 3.0 and 4.8%, respectively. The utility of the assay was demonstrated by measuring 23-hydroxybetulinicacid in mouse plasma following intragastric administration (IG) in vivo. Pharmacokinetic parameters were calculated using the 3P97 pharmacokinetic software package. A two-compartment, first-order model was selected for pharmacokinetic modeling. The result showed that after IG of 200 mg/kg 23-hydroxybetulinic acid, the plasma concentrations reached peaks at 2 h with C(max) of 3.1 microg/mL. The 200 mg/kg 23-hydroxybetulinic acid suspension IG doses were found to have long elimination half-lives of 25.6 h and low bioavailability of 2.3%. No interference was noted due to endogenous substances. These analytical methods should be of value in future studies related to the development and characterization of 23-hydroxybetulinic acid.

BBA, a Synthetic Derivative of 23-hydroxybutulinic Acid, Reverses Multidrug Resistance by Inhibiting the Efflux Activity of MRP7 (ABCC10)

“…There was no significant reduction of the body weight in nude mouse after treatment with BBA at effective reversal concentration of 15 mg/kg [22]. Although the plasma concentration of BBA was not determined in the previous nude mouse study, the plasma concentration of 23-HBA (the compound from which BBA was synthesized) was reported, where 23-HBA at 2 h attained a C max of 3.1 µg/ml (=6.56 µM) after intragastric administration (IG) of 200 mg/kg 23-HBA [48]. Nevertheless, the potential of BBA to be developed into an adjuvant to chemotherapy still needs to be further investigated, where the clinically effective plasma concentration, drug interaction and pharmacokinetics of BBA in combination with chemotherapeutic agents in vivo needs to be studied.…”

Species‐related difference between limonin and obacunone among five liver microsomes and zebrafish using ultra‐high‐performance liquid chromatography coupled with a LTQ‐Orbitrap mass spectrometer

“…Based on the accurate mass data, the structures of metabolites can be characterized and identified accurately and quickly. Although the fragments of limonin and obacunone have been reported under electron ionization (EI)‐MS conditions, their fragmentation by electrospray ionization tandem mass spectrometry (ESI‐MS/MS) should be studied comprehensively, because of the large number of determinations using ESI …”

A liquid chromatography/electrospray ionization tandem mass spectrometric method for quantification of asiatic acid from plasma: application to pharmacokinetic study in rats

“…The reason may be due to the failure to ionize low polarity triterpenoid compounds by ESI and/or the absence of prominent product ions during collision‐induced dissociation. This has been illustrated by reported LC/MS methods for quantifying pentacyclic triterpenoids such as betulinic acid, 23‐hydroxybetulinic acid and ursolic acid from biological fluids . Further, a recent work on LC/MS revealed that an ESI source was insensitive to analysis of triterpene compounds …”

“…This has been illustrated by reported LC/MS methods for quantifying pentacyclic triterpenoids such as betulinic acid, 23-hydroxybetulinic acid and ursolic acid from biological fluids. [25][26][27] Further, a recent work on LC/MS revealed that an ESI source was insensitive to analysis of triterpene compounds. [28] In the present work, a sensitive, selective and reproducible HPLC/ESI-MS/MS method has been developed for quantification of AA using colchicine as internal standard (IS) from rat plasma.…”