Quercetin is metabolised by platelets.

<p>Platelets (8×10⁸ cells.mL⁻¹) pretreated with quercetin (50 µM) and tamarixetin (50 µM) for 5, 40, 60 or 120 min were lysed with 50% methanol and 0.1% formic acid. Extracts from lysed platelets were separated by HPLC utilising UV detection (λ: 210 nm) over a period of 20 min, before identification of the protonated masses of compounds using mass spectrometry. Mass spectrums show the ([M+H⁺]⁺) of quercetin (molecular mass: 303 Da), the platelet metabolite (molecular mass: 317 Da) and the external control spike, myricetin (molecular mass: 319 Da) at 5 min (A: with plasma control inset) and 60 min (B). EIC and mass spectrums of standards show tamarixetin (EIC: C.i-RT: 7.5 min; mass spectrum: C.ii-molecular mass: 317 Da), quercetin (EIC: (D.i)-RT: 7 min; mass spectrum: (D.ii)-molecular mass: 303 Da) with inset MS spectrum showing the absence of tamarixetin (ii) and myricetin (EIC: (E.i)-RT: 6.5 min; mass spectrum: (E.ii)-molecular mass: 319 Da). Data represent 3 individual experiments using platelets isolated from 3 different blood donors.