title: Validated LC-MS method for simultaneous quantitation of catalpol and harpagide in rat plasma: application to a comparative pharmacokinetic study in normal and diabetic rats after oral administration of Zeng-Ye-Decoction.
abstract: A simple and efficient liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for simultaneous quantitation of catalpol and harpagide in normal and diabetic rat plasma. Protein precipitation extraction with acetonitrile was carried out using salidroside as the internal standard (IS). The LC separation was performed on an Elite C18 column (150 × 4.6 mm, 5 µm) with the mobile phase consisting of acetonitrile and water within a runtime of 12.0 min. The analytes were detected without endogenous interference in the selected ion monitoring mode with positive electrospray ionization. Calibration curves offered satisfactory linearity (r > 0.99) at linear range of 0.05-50.0 µg/mL for catalpol and 0.025-5.0 µg/mL for harpagide with the lower limits of quantitation of 0.05 and 0.025 µg/mL, respectively. Intra- and inter-day precisions (RSD) were <9.4%, and accuracy (RE) was in the -6.6 to 4.9% range. The extraction efficiencies of catalpol, harpagide and IS were all >76.5% and the matrix effects of the analytes ranged from 86.5 to 106.0%. The method was successfully applied to the pharmacokinetic study of catalpol and harpagide after oral administration of Zeng-Ye-Decoction to normal and diabetic rats, respectively.
authors.affiliation: Shenyang Pharmaceutical University, Wenhua Road 103, Shenhe District, Shenyang, People's Republic of China.
authors.forename: Yukun
authors.initials: Y
authors.lastname: Feng
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Peng
authors.forename: Lunhui
authors.initials: L
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Ju
authors.forename: Kaishun
authors.initials: K
authors.lastname: Bi
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy*; D004365:Drugs, Chinese Herbal / Q000493:pharmacokinetics; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000097:blood*; D057888:Iridoid Glucosides / Q000008:administration & dosage / Q000097:blood*; D057889:Iridoid Glycosides / Q000008:administration & dosage / Q000097:blood*; D057230:Limit of Detection; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D011714:Pyrans / Q000008:administration & dosage / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004365:Drugs, Chinese Herbal; D007004:Hypoglycemic Agents; D057888:Iridoid Glucosides; D057889:Iridoid Glycosides; D011714:Pyrans; C078040:catalpol; C033250:harpagide
keywords: LC-MS; Zeng-Ye-Decoction; catalpol; diabetes mellitus; harpagide; pharmacokinetics