Chemistry of Natural Compounds, Vol. 45, No. 1, 2009
FLAVONOIDS AND COUMARINS FROM Allium rotundum
M. R. Maisashvili,1 L. N. Gvazava,2 and J. K. Kuchukhidze1
UDC 547.972
L. is widely distributed over all of Georgia, is readily cultivated, and can provide an industrial base
Allium rotundum
for preparing drugs.
We identified seven sapogenins and saponins in
[1, 2] and isolated and studied phenolic compounds, in
A. rotundum
particular, flavonoids and coumarins. Herein we report results from a study of them.
We studied the aerial parts of collected during flowering near Tbilisi in Kojori village.
A. rotundum
Air-dried ground material (500 g) was extracted exhaustively with hot methanol (80°). The solvent was vacuum
distilled. The resulting thick aqueous residue was diluted with water and extracted successively with CHCl and EtOAc.
3
Solvents were distilled off to afford CHCl (9.8 g) and EtOAc (8.5 g) fractions.
3
The EtOAc fraction was purified of lipophilic substances over a column of Sephadex G-25. The purified extract was
chromatographed over a column of polyamide sorbent (eluent C H OH:CHCl in various ratios). Combined fractions were
2
5
3
rechromatographed over a column of silica gel using CHCl :CH OH (97:3 and 85:15) [3].
3
3
The CHCl extract was separated by partition chromatography over a column of silica gel with elution by petroleum
3
ether:benzene (8:2) and then CHCl . The resulting fractions were monitored by paper chromatography (PC) using
3
-BuOH:AcOH:H O (4:1:2, 1) and THF:CHCl :HCONH [50:50:6.5, paper saturated with HCONH :(CH ) CO, 2]. A total
n
2
3
2
2
3 2
of eight compounds were isolated and identified based on UV, IR, and PMR spectra and certain chemical transformations and
by direct comparison with authentic samples and the literature.
+
Quercetin (3,5,7,3′,4′-pentahydroxyflavone), C H O , [M] 302; bright yellow needle-like crystals, mp 312-313°C
15 10
7
(CH OH). PC (Filtrak FN 7, GDR): 0.77 (system 1); UV spectrum (EtOH, λ , nm): 257, 268, 371; +CH COONa: 270,
R
3
f
3
max
406.
+
Luteolin (5,7,3′,4′-tetrahydroxyflavone), C H O , [M] 286, mp 328-329°C. UV spectrum (EtOH, λ , nm): 261,
15 10
6
max
272, 355. TheIRspectrumcontainedabsorption bandsfor hydroxyls(3450-3300 cm−1), γ-pyrone carbonyl (1659), and aromatic
C=C bonds (1612, 1585).
PMR spectrum (C D N, δ, ppm, J/Hz): 7.60 (1H, dd, J = 2.2, 8.1, H-6′), 7.51 (1H, br.s, H-2′), 7.09 (1H, d, J = 8.1,
5
5
H-5′), 6.79 (1H, s, H-3), 6.70 (1H, d, J = 2.1, H-8), 6.59 (1H, d, J = 2.1, H-6).
Luteolin was acetylated by acetic anhydride in the presence of pyridine to give the tetraacetate, mp 222-223°C,
+
[M] 454.
+
Apigenin (5,7,4′-trihydroxyflavone), C H O , [M] 270, mp 347-348°C. UVspectrum (EtOH, λ , nm): 270, 312.
15 10
5
max
PMR spectrum (C D N, δ, ppm, J/Hz): 13.69 (1H, br.s, 5-OH), 7.87 (2H, d, J = 9.2, H-2′, H-6′), 7.09 (2H, d, J = 9.2,
5
5
H-3′, H-5′), 6.82 (1H, s, H-3), 6.75 (1H, d, J = 2.1, H-8), 6.61 (1H, d, J = 2.1, H-6).
20
Hyperin (quercetin-3-O-β-D-galactopyranoside), C H O , yellow crystals (EtOH), mp 235-236°C, [α]
−60.2°
(c 0.1, EtOH). PC: R 0.71 (system 1). UV spectrum (CH OH, λ , nm): 260, 362; +CH COONa: 276, 395; +CH ONa: 276,
21 20 12
max
D
f
3
3
3
405; +CH COONa + H BO : 272, 375. The IRspectrum (KBr, ν, cm−1) contained absorption bands at 3300 (OH), 1665 (C=O),
3
3
3
1615, 1565, 1515 (C=C), 1095, 1030 (C–O).
PMR spectrum (CD OD, δ, ppm, J/Hz): 7.74 (1H, dd, J = 9, 2, H-6′), 7.32 (1H, d, J = 2, H-2′), 6.79 (1H, d, J = 9,
3
H-5′), 6.42 (1H, d, J = 2, H-8), 6.15 (1H, d, J = 2, H-6). The anomeric proton of β-D-galactose resonated at 5.61 ppm,
J = 7.8 Hz.
Acid and enzymatic hydrolysis produced the aglycon quercetin (mp 309-310°C, C H O ) and D-galactose.
15 10
7
1) Tbilisi State Medical University, 0108, Tbilisi, ul. G. Akhvlediani, 22; 2) I. Kutatelidze Institute of Pharmaceutical
Chemistry, e-mail: liligvazava@yahoo.com. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 77-78, January-
February, 2009. Original article submitted June 2, 2008.
0009-3130/09/4501-0087 ©2009 Springer Science+Business Media, Inc.
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Maisashvili
