A Novel GC-MS Bioanalytical Method for Natural Borneol and Its Application in Investigating Natural Borneol Distribution in Mice

Abstract

One of the major goals of our group is to understand the meridian tropism of natural borneol (NB). As a first step, this study served two purposes: to develop a GC-MS bioanalytical method for NB, and with the aid of this method to investigate NB distribution in mice. Mouse tissue samples, spiked with naphthalene as internal standard, were homogenated with NS and extracted using hexane. The extract supernatant was analyzed in GC-MS with conditions of DB-5MS capillary column (0.25mm×30m×0.25μm), electron impact (EI) ionization with energy of 70 eV and multiplier voltage of 1100 V, and Selected Ion Monitor (SIM, m/z 95 for camphor and NB, whereas m/z 128 for naphthalene) detection mode. The calibration curve was linear in the range from 22 ng/mL to 22 μg/mL with a regression equation Y= 0.000486X + 0.00036, R²=0.999 (n=3). The limit of detection was 10 ng/mL. The lower limit of quantitation was 22 ng/mL. The within-day and inter-day precisions were 3.72∼6.11% and 7.29∼17.6%, respectively. The relative recovery was 85.95∼107.93% and extraction recovery was 93.04∼103.03%. This bioanalytical method has sufficient recovery and is accurate and reliable for quantitating NB in tissues. The tissue distribution up to 150 min after a single oral dose of NB was investigated in mice. This compound was detected in most tissues. The liver had the highest concentration, followed by kidney, heart, brain, and others. Tissue concentration-time curves had double or triple peaks. The tissue distribution pattern suggested that NB may attribute to the cardio-system.