title: Determination of betulinic acid in mouse blood, tumor and tissue homogenates by liquid chromatography-electrospray mass spectrometry.
abstract: A rapid and sensitive high-performance liquid chromatography-electrospray MS method has been developed to determine tissue distribution of betulinic acid in mice. The method involved deproteinization of these samples with 2.5 volumes (v/w) of acetonitrile-ethanol (1:1) and then 5 microl aliquots of the supernatant were injected onto a C18 reversed-phase column coupled with an electrospray MS system. The mobile phase employed isocratic elution with 80% acetonitrile for 10 min; the flow-rate was 0.7 ml/min. The column effluent was analyzed by selected ion monitoring for the negative pseudo-molecular ion of betulinic acid [M-H]- at m/z 455. The limit of detection for betulinic acid in biological samples by this method was approximately 1.4 pg and the coefficients of variation of the assay (intra- and inter-day) were generally low (below 9.1%). When athymic mice bearing human melanoma were treated with betulinic acid (500 mg/kg, i.p.), distribution was as follows: tumor, 452.2 +/- 261.2 microg/g; liver, 233.9 +/- 80.3 microg/g; lung, 74.8 +/- 63.7 microg/g; kidney, 95.8 +/- 122.8 microg/g; blood, 1.8 +/- 0.5 microg/ml. No interference was noted due to endogenous substances. These methods of analysis should be of value in future studies related to the development and characterization of betulinic acid.
authors.affiliation: Program for Collaborative Research in the Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, 60612, USA.
authors.forename: Y G
authors.initials: YG
authors.lastname: Shin
authors.forename: K H
authors.initials: KH
authors.lastname: Cho
authors.forename: S M
authors.initials: SM
authors.lastname: Chung
authors.forename: J
authors.initials: J
authors.lastname: Graham
authors.forename: T K
authors.initials: TK
authors.lastname: Das Gupta
authors.forename: J M
authors.initials: JM
authors.lastname: Pezzuto
mesh_terms: D000818:Animals; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000097:blood* / Q000378:metabolism; D053978:Pentacyclic Triterpenes; D014315:Triterpenes / Q000032:analysis / Q000097:blood*; D000094062:Betulinic Acid
chemical_list: D053978:Pentacyclic Triterpenes; D014315:Triterpenes; D000094062:Betulinic Acid