title: Determination of betulinic acid from Orthosiphon stamineus leaf extract in rat plasma.
abstract: A simple high-performance liquid chromatography (HPLC) method to determine the content of betulinic acid (BA) in rat plasma collected at different times (0-8 h) after oral administration of Orthosiphon stamineus leaf extract was developed. The features of the assay include protein precipitation using acetonitrile and isocratic elution using reverse phase C-18 column with ultraviolet (UV) detection. The recovery of BA from plasma varied from 98.4 to 102.5%. The R.S.D of intra- and inter-day precision from rat plasma ranged from 4.2 to 9.8%. The maximum concentration of BA in the plasma was 1.2 +/- 0.3 microg/ml at 1 h after oral administration of the extract.
authors.affiliation: School of Pharmacy, University College Sedaya International, 56000 Cheras, Kuala Lumpur, Malaysia. agabriel@ucsi.edu.my
authors.forename: G A
authors.initials: GA
authors.lastname: Akowuah
authors.forename: I
authors.initials: I
authors.lastname: Zhari
mesh_terms: D000818:Animals; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D003627:Data Interpretation, Statistical; D007202:Indicators and Reagents; D051379:Mice; D031342:Orthosiphon / Q000737:chemistry*; D053978:Pentacyclic Triterpenes; D010592:Pharmaceutic Aids / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018515:Plant Leaves; D011205:Povidone / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards; D021241:Spectrometry, Mass, Electrospray Ionization; D014315:Triterpenes / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D000094062:Betulinic Acid
chemical_list: D007202:Indicators and Reagents; D053978:Pentacyclic Triterpenes; D010592:Pharmaceutic Aids; D010936:Plant Extracts; D014315:Triterpenes; D011205:Povidone; D000094062:Betulinic Acid