Simultaneous Determination of Volatile Constituents from Acorus tatarinowii Schott in Rat Plasma by Gas Chromatography-Mass Spectrometry with Selective Ion Monitoring and Application in Pharmacokinetic Study

A sensitive and specific gas chromatographic-mass spectrometry with selected ion monitoring (GC-MS/SIM) method has been developed for simultaneous identification and quantification of α-asarone, -asarone, and methyl eugenol of Acorus tatarinowii Schott in rat plasma. Chromatographic separation was performed on a Restek Rxi-5MS capillary column (30？m × 0.32？mm × 0.25？ m), using 1-naphthol as internal standard (IS). MS detection of these compounds and IS was performed at m/z 178, 208, 208, and 144. Intra- and interday precisions of all compounds of interest were less than 10%. The recoveries are situated in the range of 92.4–105.2%. Pharmacokinetics of methyl eugenol confirmed to be one-compartment open model, α-asarone and β-asarone was two-compartment open model, respectively. The method will probably be an alternative to simultaneous determination and pharmacokinetic study of volatile ingredients in Acorus tatarinowii Schott. 1. Introduction Chinese medicines have played an important role in clinical therapy in China, Korea, and Japan attributed to high pharmacological activity and few complications. As a classic medicinal plant, the dry rhizome of Acorus tatarinowii Schott is officially listed in the Chinese Pharmacopoeia and widely used for fighting ailments such as epilepsy, digestive disorders, cerebrovascular disease, stroke, senile dementia, and diarrhea [1–5]. Recent studies have found that aqueous extract and volatile oil of Acorus tatarinowii Schott dose-dependently suppressed the intensity of APO-induced stereotypic behavior and locomotor activity and extended the duration of sleeping induced by pentobarbital [6, 7]. Inhalation of the volatile oil also has the properties of reversing decreased brain GABA levels induced by PTZ inhibition of GABA transaminase [8]. Low polar or nonpolar compounds including -asarone, -asarone, and methyl eugenol proved to be main bioactive ingredients in volatile oil of Acorus tatarinowii Schott in previous report [9]. -Asarone has significant pharmacological effects on cardiovascular and central nervous system, while -asarone possesses hypocholesterolemic, hypolipidemic, neuroprotective, and antiepileptic activities [10–16]. Methyl eugenol was also found to have antinociceptive, antibacterial, and antidepressive activities [17, 18]. These compounds were often used as reference standards for quality control of Acorus tatarinowii Schott due to outstanding pharmacological activities. The development of sensitive and rapid approach for simultaneous determination of these compounds was owing to increasing interest in