ABTS	2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)
DPPH	2,2-Diphenyl-1-picrylhydrazyl
ESI	Electrospray ionization
FeCl3·6H2O	Ferric chloride hexahydrate
FeSO4·7H2O	Ferrous sulfate heptahydrate
FLR	Fluorescence
FRAP	Ferric-reducing antioxidant power
GAE	Gallic acid equivalents
GtE	Galeopsis tetrahit extract
HH	Half height
HPLC	High-performance liquid chromatography
IC50	Half-maximal inhibitory concentration
ICH	International Council for Harmonisation
LC–MS/MS	Liquid chromatography–tandem mass spectrometry
LOD	Limit of detection
LOQ	Limit of quantification
m/z	Mass-to-charge ratio
MS	Mass spectrometry
PDA	Photodiode array
PhGs	Phenylethanoid glycosides
QE	Quercetin equivalents
r	Correlation coefficient
r2	Coefficient of determination
RMSD	Root-mean-square deviation
RSD	Relative standard deviation
SD	Standard deviation
TFC	Total flavonoid content
TPC	Total phenolic content
TPTZ	2,4,6-Tris(2-pyridyl)-1,3,5-triazine
tR	Retention time
UHPLC	Ultra-high-performance liquid chromatography
USP	United States Pharmacopoeia
UV	Ultraviolet