1) Xinjiang Technical Institute of Physics and Chemistry, Academy of Sciences of the PRC, Urumchi, 830011, China,
fax (86991) 383 56 79, e-mail: haji@ms.xjb.ac.cn; 2) Graduate School of the PRC, Beijing, 100039, PRC. Translated from
Khimiya Prirodnykh Soedinenii, No. 3, pp. 296-297, May-June, 2008. Original article submitted April 3, 2008.
0009-3130/08/4403-0370
©
2008 Springer Science+Business Media, Inc.
370
Chemistry of Natural Compounds, Vol. 44, No. 3, 2008
FLAVONOIDS FROM Gossypium hirsutum FLOWERS
T. Wu,
1,2
R. Abdulla,
1,2
Y. Yang,
1,2
and H. A. Aisa
1*
UDC 547.972
Gossypium hirsutum
L. (Malvaceae) is a cotton species that is widely cultivated worldwide. In Xinjiang Autonomous
Region (PRC), flowers of
G. hirsutum
are used in folk medicine. The plant is officially listed as a Chinese Medicinal Herb and
is used as a sedative agent and to treat delayed mental development and to improve brain function [1]. We studied the flavonoid
composition of flowers of
G. hirsutum
.
Flowers of
G. hirsutum
(2 kg) were extracted with ethanol (95%, 3 times). The extracts were combined and evaporated
to dryness at reduced pressure to afford dry powder (400 g) that was fractionated over a column of ion-exchange resin AB-8
(weakly polar). Compounds were eluted from the column by water and aqueous ethanol (50 and 70%). The alcohol fractions
(90 g) were rechromatographed over a column of silica gel to produce
1
-
7
.
Kaempferol-3-
O
-
β
-D-(6″-O-p-coumaryl)glycoside (1), light-yellow powder, mp 246-248°C (MeOH). UV spectrum
(λ
max
, MeOH, nm): 226, 268, 316, 352sh.
PMR spectrum (600 MHz, DMSO-d
6
, δ, ppm, J/Hz): 5.46 (1H, d, J = 7.8, H-1″), 6.12 (1H, d, J = 16.2, H-8′″), 6.16
(1H, d, J = 1.8, H-6), 6.39 (1H, d, J = 1.8, H-8), 6.79 (2H, d, J = 8.4, H-3′″,5′″), 6.86 (2H, d, J = 9.0, H-3′,5′), 7.35 (1H, d,
J = 16.2, H-7′″), 7.38 (2H, d, J = 8.4, H-2′″,6′″), 8.00 (2H, d, J = 9.0, H-2′,6′), 10.03, 10.17 (1H each, br.s, OH on C-4′″ and
C-4′, respectively), 10.86 (1H, br.s, 7-OH), 12.59 (1H, s, 5-OH).
13
C NMR spectrum (150 MHz, DMSO-d
6
, δ, ppm): 177.6 (C-4), 166.4 (C-9′″), 164.4 (C-7), 161.4 (C-5), 160.2 (C-4′),
160.0 (C-4′″), 156.6 (C-2), 156.5 (C-9), 144.8 (C-7′″), 133.2 (C-3), 131.0 (C-2′,6′), 130.4 (C-2′″,6′″), 125.1 (C-1′″), 121.0
(C-1′), 116.0 (C-3′,5′), 115.3 (C-3′″,5′″), 113.8 (C-8′″), 104.1 (C-10), 101.1 (C-1″), 99.0 (C-6), 93.9 (C-8), 76.4 (C-3′), 74.4
(C-5″), 74.3 (C-2″), 70.1 (C-4″), 63.2 (C-6″) [2].
Quercetin (2), yellow powder, mp >300°C (acetone). UV spectrum (λ
max
, MeOH, nm): 256, 374.
PMR spectrum (600 MHz, DMSO-d
6
, δ, ppm, J/Hz): 6.19 (1H, d, J = 1.8, H-6), 6.41 (1H, d, J = 2.4, H-8), 6.88 (1H,
d, J = 8.4, H-5′), 7.55 (1H, q, J = 8.4, 2.4, H-6′), 7.68 (1H, d, J = 2.4, H-2′), 9.32 (1H, s, 4′-OH), 9.39 (1H, s, 3-OH), 9.61 (1H,
s, 3′-OH), 10.79 (1H, s, 7-OH), 12.50 (1H, s, 5-OH).
13
C NMR spectrum (150 MHz, DMSO-d
6
, δ, ppm): 93.55 (C-8), 98.38 (C-6), 103.21 (C-10), 115.80 (C-2′), 116.39
(C-5′), 120.17 (C-6′), 122.15 (C-1′), 135.95 (C-3), 145.26 (C-3′), 146.99 (C-2), 147.91 (C-4′), 156.32 (C-9), 160.92 (C-5),
164.09 (C-7), 176.05 (C-4) [3].
Quercetin-3′-O-
β
-D-glucoside (3), yellow powder, mp 183-184°C (MeOH). UV spectrum (λ
max
, MeOH, nm): 252,
370.
PMR spectrum (600 MHz, DMSO-d
6
, δ, ppm, J/Hz): 3.17-5.09 (sugar protons), 5.15 (1H, d, J = 4.2, H-1″), 6.19 (1H,
d, J = 1.8, H-6), 6.49 (1H, d, J = 1.8, H-8), 6.98 (1H, d, J = 8.4, H-5′), 7.85 (1H, q, J = 8.4, 2.4, H-6′), 7.96 (1H, d, J = 1.8, H-2′),
9.22 (1H, s, 4′-OH), 9.42 (2H, s, 3-OH), 10.67 (1H, s, 7-OH), 12.46 (1H, s, 5-OH).
13
C NMR spectrum (150 MHz, DMSO-d
6
, δ, ppm): 60.76 (C-6″), 69.73 (C-4″), 73.49 (C-2″), 76.14 (C-3″), 77.42
(C-5″), 93.90 (C-8), 98.44 (C-6), 102.59 (C-1″) 103.22 (C-10), 115.93 (C-2′), 116.20 (C-5′), 122.42 (C-6′), 123.77 (C-1′),
136.20 (C-3), 145.49 (C-3′), 146.43 (C-2), 148.98 (C-4′), 156.39 (C-9), 160.84 (C-5), 164.22 (C-7), 176.13 (C-4) [4, 5].
Quercetin-3-O-
β
-D-glucoside (4), yellow powder, mp 249-250°C (MeOH). UV spectrum (λ
max
, MeOH, nm): 257,
361.