Characterization of Isolated Quercetin Rutinose

The physical state of the CSSGLT isolated QRT was characterized using DSC thermogram analysis (Mettler Toledo DSC 822e; India). 2.93 mg of QRT was weighed separately in standard aluminum pans. A DSC instrument was used for measurement of the melting temperature of QRT with an empty reference aluminum pan. The sample was purged in the DSC with pure dry nitrogen gas which was set at a flow rate of 40 mL min⁻¹. The change in temperature was set at 5 °C min⁻¹, and the heat flow was recorded from 25 °C to 400 °C. Heat flow was measured by comparing the difference in temperature across the sample and the reference. UV-visible spectroscopic analysis was performed using LAB UV3000^plus at room temperature with a quartz cuvette of 1 cm path-length as the sample holder (200–800 nm). IR spectra were recorded in the transmittance range of 4000 to 400 cm⁻¹ on PerkinElmer FTIR spectrometer Frontier using ATR. The ¹H and ¹³C NMR spectra of the QRT were recorded at 500 mHz (¹H NMR) and 125 mHz (13C NMR) using the Bruker (Advance) NMR instrument in DMSO solvent.^{41 (link)1}H NMR (500 MHZ, DMSO-d₆): δ 6.18 (d, 1H, J = 2 Hz), 6.40 (d, 1H, J = 1.5 Hz), 6.87 (d, 1H, J = 9 Hz), 7.52 (dd, 1H, J = 2.5 and 8.5 Hz), and 7.67 (d, 1H, J = 2.5 Hz). ¹³C NMR (125 MHZ, DMSO-d₆): δ 93.32, 98.15, 102.98, 115.03, 115.57, 119.94, 121.92, 135.70, 145.03, 146.77, 147.67, 156.11, 160.69, 163.85, and 175.81.