Table 2. LC-MS analysis condition for DHNA

Item	Operation condition
LC-MS system	1290 Infinity II LC system (Agilent, USA)6470 Triple Quadrupole (QQQ) LC/MS system1) (Agilent, USA)
Column	Poroshell 120, EC-C18 (2.1 × 100mm, 2.7 μm; Agilent, USA)
Solvent	Solvent A: 0.1% formic acid in waterSolvent B: 0.1% formic acid in acetonitrile
Gradient	0 min (A 90%, B 10%) → 0.5 min (A 90%, B 10%) → 7 min (B 100%) → 13 min (B 100%)
Column temperature	30°C
Flow rate	0.4 mL/min
Injection volume	5 μL
UV detection	UV 260 nm

QQQ LC-MS system was used for ESI (Electrospray ionization) of isolated compounds.