Quercetin, a flavonoid natural product, is a SIRT1 activator. It is also a PI3K inhibitor, inhibiting PI3Kγ, PI3Kδ, and PI3Kβ with IC50 values of 2.4, 3.0, and 5.4 μM, respectively. Recognized as a heat shock protein inhibitor, Quercetin can significantly reduce exosome release in TII models by downregulating Hsp70 or Hsp90.

Quercitrin (3-rhamnosyl quercetin) is a plant-derived flavonoid compound, displays antioxidant and anti-inflammatory activities. Quercitrin can be found in a number of food items such as garden tomato (var. ), German camomile, endive, and kiwi, which makes quercitrin a potential biomarker for the consumption of these food products.