Table 1.

Natural sources and content (mg/100 g or mg/100 ml) of some flavonols and flavones.

Substance	Food source	Estimated content (mg/100 g fresh weight)	Reference
Quercetin	Tomatoes	7-55	[26]
	Lettuce	2-911
	Onions	10-1359
	Peas	98-145
	Apple	2-26	[22]
	Apricot	2-5
	Broccoli	0-3
	Chives	10-30
	Cramberry	149
	Grape, red	1-3
	Cramberry	25	[44]
	Oregano	42
	Dill	79
	Lovage	170	[45]
	Radish leaves	70
	Watercress	29
Kaempferol	Kale	47	[44]
	Spinach	55
	Chives	12
	Dill	40
	Cabbage	20-25	[45]
	Watercress	23
Luteolin	Celery	6-40	[26]
	Mexican oregano	901-1137	[46]
	Spices, celery seed	811	[47]
Apigenin	Celery	17-191	[26]
	Spinach	1	[48]
	Green pepper	0-1
	Welsh onion	8-11
	Parsley	4503	[49]
	Chamomile	300-500
	Vine-spinach	62
Baicalein	Wine, tea, citrus fruits, dark chocolate, and herbs	n.d.	[50]
	Roots of Scutellaria baicalensis (traditional Chinese herbal medicine)	n.d.	[51]
	Welsh onion	9	[48]
	Spinach	19
Scutellarein	Mexican oregano	24-48	[47]
Tangeretin	Citrus fruits, Orange juice (pure)	8∗	[52]
Nobiletin	Grape fruits, teas (Camellia sinensis), herbal tea, and black tea	n.d.	[53]

n.d.: not described; ^∗mg/100 ml.