Hesperetin is a bioflavonoid and, to be more specific, a flavanone. Hesperidin

Hesperidin

Hesperidin is a flavanone glycoside found abundantly in citrus fruits. Its aglycone form is called hesperetin. Its name is derived from the Hesperides nymphs of Greek mythology. Hesperidin is believed to play a role in plant defense. It acts as an antioxidant according to in vitro studies...

 (a flavonone glycoside) is water-soluble due to the presence of the sugar part in its structure, so on ingestion it releases its aglycone

Aglycone

An aglycone is the non-sugar compound remaining after replacement of the glycosyl group from a glycoside by a hydrogen atom. The spelling aglycon is sometimes encountered .Classes of phytochemicals found in the aglycone and glycosides forms :...

, i.e, hesperetin.

Hesperidin is found in Citrus

Citrus

Citrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...

 fruits.

Glycosides

Neohesperidin is the 7-neohesperidoside of hesperetin.

Hesperetin 7-rhamnoside can be isolated from Cordia obliqua.