A rapid HPLC-ESI-MS/MS method for determination of β-asarone, a potential anti-epileptic agent, in plasma after oral administration of Acorus calamus extract to rats.

β-Asarone (BAS), a phenylpropanoid from Acorus calamus Linn., has shown biological effects in the management of cognitive impairment conditions such as Alzheimer's disease. The present paper describes a selective and sensitive liquid chromatography-tandem mass spectrometric method (HPLC-MS/MS) using electrospray ionization source (ESI) for quantification of BAS in rat plasma. Briefly, the plasma samples were pre-treated using a simple solid-phase extraction method. The separation of BAS and the internal standard, caffeine, was achieved on an Agilent Zorbax XDB C(18) column (50 × 2.1 mm i.d., 5 µm) using 0.2 mL/min isocratic mobile phase flow. The detection was performed using an Applied Biosystems Hybrid Q-Trap API 2000 mass spectrometer equipped with an ESI source operated in positive mode. Also, the developed bioanalytical method was validated as per the US FDA bioanalytical guidelines over the concentration range of 9.79-4892.50 ng/mL (r(2) ≥ 0.9951) for BAS from rat plasma. The mean percentage recovery (n = 3) for the low, middle and high quality control samples was 86.92 ± 3.89, 85.30 ± 1.09 and 87.24 ± 4.03%, respectively. The applicability of the validated HPLC-MS/MS method was demonstrated by successful measurement of BAS from plasma following oral administration of Acorus calamus rhizome extracts to three female albino Wistar rats.