Identification of eupalitin- 3-O- β-D-galactopyranoside
The compound appareled as dull yellow florescent under UV light because
a flavone with free hydroxyl group at 5th position.
The compound’s EIMS revealed a molecular ion peak at m/z 184(A+) and
121(B+), respectively, indicating the presence of one hydroxyl in the
b-ring and two methoxyl groups, one hydroxyl in the a-ring . The
aromatic region of 1H NMR (in DMSO-d6, 400 MHz) revealed three signals
at δ 6.40 (1H,s), δ6.94(2H,d, J=8.5 Hz), and δ8.06(2H,d, J=8.5 Hz),
which were assigned to H-8,H-31/5’, and H-2’/6’, respectively. Two
signals in the aliphatic region at δ3.76 (3H,s) and δ3.87(3H,s) were
identified to –OCH3 groups at C-6 and C-7 position present in the
A-ring. Thus compound has been deduced to be 4’, 5-dihydroxyl-6,7-
Figure 2: 1HNMR spectra of eupalitin-3-O-
β-D-galactopyranoside dimethoxyflavonol or eupalitin.