1286
afford chloroform crude extract as dark yellow slush. The chloroform crude extract
was separated using a column (3 cm in diameter and 30 cm in length) packed with
hexane slurry of silica gel 60 Art. 7734 to the height of 20 cm. The crude extract was
dissolved in a small amount of chloroform and loaded onto the top of the column. The
column was then eluted successively with hexane, hexane: chloroform (1:1),
chloroform, chloroform: methanol (1:1), and methanol to yield 3,5,7-
trihydroxyflavone (galangin)
1
, 3,5,7-trihydroxy-4'-methoxyflavone (kaempferide)
2
and 5,7-dihydroxy-4'-methoxy-3-
O
-ȕ-D-glucopyranosideflavone (kaempferide-3-
O
-
ȕ-D-glucoside)
3
Results and Discussion
Compound
1
was obtained as a light yellow powder and the UV spectrum
displayed bands at 267 and 370 nm and the IR spectrum showed strong absorption
band at 3607-3084, 1659, 1600, 1550 and 1260 cm
-1
suggested that compound
1
is a
flavonoid derivative compounds(Maria 2007). The
1
H-NMR and
13
C-NMR spectra of
compound
1
(Table 1) showed the necessary diagnostic peaks to be identified as a
flavonoid derivative with hydroxyl group on C-3, C-5 and C-7, appearing as sharp
singlets at į 9.59, 12.43 and 10.74 ppm, respectively. The H-6 and H-8 occurred as
sharp doublet at į 6.21 and 6.43 ppm, respectively (
J
H8/H6 = 1.53 Hz). The B ring
signals were easily assigned by consideration of symmetry. The H-2' and H-6'
resonances occurred as sharp doublet at į 8.20 ppm. The H-3' and H-5' resonances
appeared as doublet of doublets at į 7.62 ppm and H-4' occurred as muiltplet at į 7.53
ppm. The
13
C experiments of compound
1
gave thirteen peaks. The most downfield
shifted peak was 178.1 ppm which was assigned as ketone group (C-4). By direct comparison
of the
1
H-NMR and
13
C-NMR data of conpound
1
(Table 1) with those of the known
compound 3,5,7-trihydroxyflavone (galangin) (Rubens 2005) they were closely equivalent
indicating that compound
1
is 3,5,7-trihydroxyflavone (galangin) (Fig. 1).
Compound
2
was obtained as a light yellow powder and the UV spectrum
displayed bands 272, 315 and 378 nm and the IR spectrum showed strong absorption
band at 3650-3300, 2950, 2875, 1640, 1610, 1425 and 1125 cm
-1
suggested that
compound
2
is a flavonoid derivative compound similar to compound 1(Rubens 2005).
The
1
H-NMR and
13
C-NMR spectra of compound
2
(Table 1) showed the necessary
