Quercetin Analysis

Quercetin isolated from acacia catechu is a bio-active flavonoid molecule. It has been reported as a potential anticancer agent, and shows tyrosine kinase inhibition activity 61. Quercetin is a bio-active aglycone bioflavonoid used in the human diet. Its molecular formula was established as C15H10O7 by high resolution mass spectrometry as mass spectrum, shows the appearance of a molecular ion peak at 302 (M+). A broad absorption band appeared in the IR spectrum, (fig.2.3) at 3484.74cm-1 was due to the presence of the hydroxyl group. A sharp absorption band appeared at 1680.24cm-1 shows the presence of a ketoneic group. While peaks appeared in 1604 and 1053cm-1 shows the presence of aromatic C=C unsaturation and the ether groups respectively.
1H NMR spectrum, (fig.2.4) revealed the presence of a characteristic signal, a doublet at δ ppm 7.67(1H,J=2.29 Hz) appeared for one aromatic proton while a double doublet at appeared at δ ppm 7.54(1H,J=8.39 Hz) other single aromatic proton .A doublet at δ ppm 6.88(1H,J=8.39Hz) one aromatic proton.
A doublet at δ ppm 6.40(1H, J=2.29Hz) and A five broad singlet at δ ppm 6.18 (5H,J=1.91Hz) due to four phenolic protons and one aromatic alcoholic proton. From the above spectral data it appeared to be quercetin and confirmed by comparison with an authentic
sample.