Quercetin particles with lower inhibitory activity for ?-glucosidase and negligible effects on blood clotting

Poly(quercetin) (p(QR)) particles were synthesized by using poly (ethylene glycol) diglycidyl ether (PEGGE) crosslinker in a single step via a microemulsion system. The morphological, size, and functional analysis of the prepared particles were examined by optical microscope, scanning electron microscope (SEM), dynamic light scattering (DLS) measurements, and FT-IR spectroscopy. P(QR) particles were found to have spherical shape with 372±9 nm size range based on SEM images and DLS measurements. The zeta potential measurements, performed at different pH conditions, and potentiometric titration of p(QR) particles revealed that the isoelectric point and pKa values were around pH 2.5 and 2.3, respectively. Ferric reducing antioxidant power (FRAP) was determined for QR and p(QR) particles at pH 3.6 and found to be 9.4 and 0.43 µg of reduced Fe(II). The effects of QR and p(QR) particles on α-glucosidase enzyme activity were investigated at pH 6.9 and QR molecules and p(QR) particles can inhibit the α-glucosidase enzyme by 89.3% and 24.7%, respectively. The fluorescence spectroscopy of QR and p(QR) with fibrinogen showed that p(QR) particles do not induce clotting of blood.