Table 1.

Phenolic compounds analyzed in this study (phenolic acids and subgroups of flavonoids) along with reference standard names, sample codes and substituents (reproduced and slightly modified from this table in Platzer et al. (11, 14)).

Subgroups	Reference standards	Code	Position and substituents
Phenolic acids			1	3	4	5
	Caffeic acid	CAA	(CH2)2COOH	OH	OH	H
	3,4-dihydroxybenzoic acid	DBA	COOH	OH	OH	H
	Ferulic acid	FEA	(CH2)2COOH	OCH3	OH	H
	Gallic acid	GAA	COOH	OH	OH	OH
	4-hydroxybencoic acid	HBA	COOH	H	OH	H
	p-coumaric acid	PCA	(CH2)2COOH	H	OH	H
	Sinapic acid	SIA	(CH2)2COOH	OCH3	OH	OCH3
	Syringic acid	SRA	COOH	OCH3	OH	OCH3
Flavonols			2'	3'	4'	5'	3	5	7
	Isorhamnetin	IRT	H	OCH3	OH	H	OH	OH	OH
	Kaempferol	KAE	H	H	OH	H	OH	OH	OH
	Morin	MOR	OH	H	OH	H	OH	OH	OH
	Myricetin	MYR	H	OH	OH	OH	OH	OH	OH
	Quercetin-3-D-glucoside	QGU3	H	OH	OH	H	Gal	OH	OH
	Quercetin-7-D-glucoside	QGU7	H	OH	OH	H	OH	OH	Glc
	Quercetin	QUR	H	OH	OH	H	OH	OH	OH
Flavanones			3'	4'	3	5	7
	Hesperetin	HES	OH	OCH3	H	OH	OH
	Narirutin	NAR	H	OH	H	OH	2 Glc
	Naringin	NAG	H	OH	H	OH	Rham, Glc
	Naringenin	NAN	H	OH	H	OH	OH
	Taxifolin	TAF	OH	OH	OH	OH	OH
Dihydrochalcones			4	2'	4'	6'
	Phloridzin	PHD	OH	OH	OH	Glc
	Phloretin	PHT	OH	OH	OH	OH
Flavanols			3'	4'	3	4	5	7
	(+)-catechin	CAT	OH	OH	OH	H	OH	OH
	(−)-epicatechin	EPC	OH	OH	OH	H	OH	OH