quercetin

American  

[kwur-si-tin] / ˈkwɜr sɪ tɪn /

noun

Chemistry.

1. a yellow, crystalline, slightly water-soluble powder, C 1 5 H 1 0 O 7 , obtained from the bark of the quercitron and other vegetable substances, used as a yellow dye; flavin.

---

quercetin British  

/ ˈkwɜːsɪtɪn, kwɜːˈsɛtɪk, -ˈsiː- /

noun

1. Also called: flavin.  a yellow crystalline pigment found naturally in the rind and bark of many plants. It is used in medicine to treat fragile capillaries. Formula: C 15 H 10 O 7 ; melting pt: 316–7°C

---

Other Word Forms

• quercetic adjective

Etymology

Origin of quercetin

1855–60; < New Latin quercēt ( um ) an oak grove ( Latin querc ( us ) oak ( see quercine) + -ētum suffix of places where a given plant grows) + -in ²

Example Sentences

Plant-based supplements containing quercetin, curcumin, and piperine improved fatigue compared with placebo.

From Science Daily • Jan. 8, 2026

For example, the skin of an apple contains quercetin, a powerful antioxidant, along with much of the fruit’s dietary fiber.

From Salon • Jan. 12, 2025

Some other phenolics had varying effects, but quercetin glucuronide was the winner.

From Salon • Dec. 16, 2024

In this case, other foods that contain quercetin are not associated with headaches, so you might not initially consider quercetin as the cause of the red wine problem.

From Salon • Dec. 16, 2024

So-called Flavine is a commercial preparation of Quercitron Bark consisting of quercitrin or of quercetin; it is much used by wool-dyers for the production of bright yellow and orange colours.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 8 "Dubner" to "Dyeing" by Various