Fisetin

Fisetin is a plant flavonol from the flavonoid group of polyphenols. It occurs in many plants where it serves as a yellow pigment. It is found in many fruits and vegetables, such as strawberries, apples, persimmons, onions, and cucumbers.
Its chemical formula was first described by Austrian chemist Josef Herzig in 1891.

Research

Although fisetin has been under laboratory research over several decades for its potential role in senescence or anticancer properties, among other possible effects, there is no clinical evidence that it provides any benefit to human health, as of 2018.