quercetin

noun

quer·​ce·​tin ˈkwər-sə-tən 

: a yellow crystalline pigment C₁₅H₁₀O₇ occurring usually in the form of glycosides in various plants

Examples of quercetin in a Sentence

Recent Examples on the Web

Grapes Grapes have beneficial plant compounds called polyphenols, such as anthocyanins (found in red, purple, and blue grapes) and quercetin. —Merve Ceylan, Health, 22 Sep. 2025

Chia Seeds Chia seeds are rich in soluble fiber and quercetin, an antioxidant that may support heart health by reducing inflammation. —Abby Norman, Verywell Health, 26 Aug. 2025

Vaccine developers can profit from their products, but designing and testing a vaccine is a lot more work than selling a plant flavonol called quercetin as a treatment for COVID, and supplements are not subject to the same kind of regulatory oversight as drugs. —Rivka Galchen, New Yorker, 27 June 2025

Growing methods may play a role Grapes produce quercetin in response to sunlight. —Amy McGorry, FOXNews.com, 9 May 2025

Word History

Etymology

International Scientific Vocabulary, from Latin quercetum oak forest, from quercus oak — more at fir

First Known Use

1856, in the meaning defined above

Medical Definition

quercetin

noun

quer·​ce·​tin ˈkwər-sət-ən 

: a yellow crystalline pigment C₁₅H₁₀O₇ occurring usually in the form of glycosides in various plants