conditionsAll LC-MS/MS analyses were performed with an Agilent 1200series HPLC system coupled with an API 3200 mass spectrometer(MDS Sciex, Concord, ON, Canada) equipped with electrospray ion-ization (ESI) and atmospheric-pressure chemical ionization (APCI)sources. The chromatographic separation analysis was carried outwith a HECTOR-M C18 column (150 × 4.6 mm, i.d., 3 m; RS TechCorporation, Daejeon, Korea). The column was maintained at 30◦C,and a binary gradient separation was performed using a flow rate of0.4 mL/min. The mobile phases consisted of solvent A (0.1% formicacid in water) and solvent B (acetonitrile). The gradient profile was0–11 min linear increase in B from 6% to 37%; 11–14 min held at37% B; 14–15 min linear increase in B from 37% to 98%; 15–21 minheld at 98% B and 21–30 min (post acquisition time) starting mobilephase 6% B to re-equilibrate the column. The total run time for eachinjection was 30 min, and the injection volume was 2 L. The massspectrometer was run in the positive-ion mode of the ESI source,and the mass spectrometric conditions were as follows: curtain gas,20 psi; electron voltage, 5000 V; temperature, 450◦C; nebulizinggas, 50 psi; and heating gas, 50 psi.