Quercetin 3,4'-diglucoside is a flavonol glycoside found in onions (''

Allium cepa An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion ...

'') and in horse chestnut seeds (''

Aesculus hippocastanum ''Aesculus hippocastanum'', the horse chestnut, is a species of flowering plant in the maple, soapberry and lychee family Sapindaceae. It is a large, deciduous, synoecious (hermaphroditic-flowered) tree. It is also called horse-chestnut, Europe ...

'').

References

Quercetin glycosides Flavonol glucosides {{aromatic-stub