Quercetin-d3 hydrate is a deuterated form of quercetin hydrate, known as a flavonoid that stimulates recombinant SIRT1 and acts as a PI3K inhibitor. It has IC50 values of 2.4 μM, 3.0 μM, and 5.4 μM for PI3Kγ, PI3K δ, and PI3Kβ, respectively.

Quercetin hydrate is a plant-based chemical (phytochemical) used as a supplement and as an ingredient in beverages or foods. Some studies suggest it may have anti-inflammatory and antioxidant properties, with extensive potential health benefits under investigation. Quercetin hydrate functions as a PI3K inhibitor with an IC50 ranging from 2.4 to 5.4 μM. It effectively inhibits PI3K and Src kinase, moderately inhibits Akt1/2, and has minor effects on PKC, p38, and ERK1/2. Additionally, quercetin hydrate suppresses TNF-induced LDH% release, EC-dependent neutrophil adherence to bovine pulmonary artery endothelial cells (BPAEC), and inhibits BPAEC DNA synthesis and proliferation.

The combination of quercetin hydrate (75 mg/kg) and 2-methoxyestradiol enhances the inhibition of xenograft tumor growth in human prostate cancer LNCaP and PC-3 cells.