Olive Mill Waste Extracts: Polyphenols Content, Antioxidant, and Antimicrobial Activities

Table 2

Major phenolic compounds identified in OCE.

Compounds	[M-H]^+	Main fragments	Area		References
	()	ESI-MS	P	M
Phenolic alcohols
Tyrosol	139		ID	ID	[5, 14–19]
Hydroxytyrosol	155		ID	ID	[5, 14–16, 20–22]
Phenolic acids
Vanillic acid	169		ID	ID	[15, 17, 19, 22–24]
Caffeic acid	181		ID	NI	[4, 5, 13, 14, 16, 19, 23]
Sinapic acid	225		ID	ID	[22, 23]
Dihydroxymandelic acid	185		ID	ID	[15]
Vanillin	153		ID	ID	[5, 16, 23, 24]
Secoiridoids and derivatives
Oleuropein	541	227/225, 303/301	ID	ID	[4, 5, 14, 15, 17, 24, 25]
3,4-DHPEA-EA	379		ID	ID	[5, 16, 17, 19, 20]
3,4-DHPEA-EDA	321		ID	NI	[5, 17]
Oleuropein derivatives	369	225/223, 141/139	NI	ID	[5, 17]
Elenolic acid (p-HPEA-EDA)	243	225/223, 197/195, 179/177	ID	ID	[5, 15–17, 19, 22]
Ligstroside	525	395/393	ID	ID	[5, 14, 15, 23]
p-DHPA-EA	363		NI	ID	[5, 16, 17, 19, 20]
Ligstroside derivatives	337	217/215, 155/153	ID	ID	[5, 20, 24]
Ligstroside derivatives	293		ID	NI	[20]
Ligstroside derivatives	395	259/257	ID	ID	[20]
Hydroxytyrosol glucoside	317	137/135	ID	NI	[5, 15, 16]
Oleoside	391		ID	NI	[14, 15, 23, 26]
Verbascoside	365		ID	NI	[14, 15, 23, 24]
Flavonoids
Apigenin	271		NI	ID	[5, 14, 16, 19, 22, 23]
Luteolin	287	153/151	ID	ID	[5, 14, 15, 20, 22, 24]
Luteolin-7-glucoside	449	287/285	NI	ID	[5, 14–16, 19, 23, 24]
Nüzhenide	685		NI	ID	[19]
Quercetin	303		ID	ID	[14, 22, 23]

Masse/charge, in the positive mode.
ID: Identified; NI: not identified.
P: plain/M: mountain.
3,4-DHPEA-EA: oleuropein aglycon, p-DHPA-EA: ligstroside aglycon, 3,4-DHPEA-EDA: oleuropein aglycon isomer in aldehyde form, and 3,4-DHPEA-AC: hydroxytyrosol acetate.