Irisdichotins A-C, three new flavonoid glycosides from the rhizomes of Iris dichotoma Pall.

Article abstract of DOI:10.1080/10286020.2011.587806

Three new compounds including one flavonol glycoside, irisdichotin A (1), and two flavanonol glycosides, irisdichotinsB (2) and C (3), were isolated from the rhizomes of Iris dichotoma Pall. Their structures were elucidated on the basis of spectroscopic methods.

Full text of DOI:10.1080/10286020.2011.587806

This article was downloaded by: [Moskow State Univ Bibliote]
On: 13 February 2014, At: 07:25
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered
office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Journal of Asian Natural Products
Research
Publication details, including instructions for authors and
subscription information:
http://www.tandfonline.com/loi/ganp20
Irisdichotins A–C, three new flavonoid
glycosides from the rhizomes of Iris
dichotoma Pall.
Long Huang a , Wen-Hui Ma b , Yan-Ze Liu a , Jun-Shan Yang a , Yong
Peng a & Pei-Gen Xiao a
a Institute of Medicinal Plant Development, Chinese Academy
of Medical Sciences and Peking Union Medical College , Beijing,
100193, China
b Shanghai Micronmr Information Technology Co., Ltd. , Shanghai,
200437, China
Published online: 13 Jul 2011.
To cite this article: Long Huang , Wen-Hui Ma , Yan-Ze Liu , Jun-Shan Yang , Yong Peng &
Pei-Gen Xiao (2011) Irisdichotins A–C, three new flavonoid glycosides from the rhizomes
of Iris dichotoma Pall., Journal of Asian Natural Products Research, 13:8, 744-748, DOI:
10.1080/10286020.2011.587806
To link to this article: http://dx.doi.org/10.1080/10286020.2011.587806
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the
“Content”) contained in the publications on our platform. However, Taylor & Francis,
our agents, and our licensors make no representations or warranties whatsoever as to
the accuracy, completeness, or suitability for any purpose of the Content. Any opinions
and views expressed in this publication are the opinions and views of the authors,
and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content
should not be relied upon and should be independently verified with primary sources
of information. Taylor and Francis shall not be liable for any losses, actions, claims,
proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or
howsoever caused arising directly or indirectly in connection with, in relation to or arising
out of the use of the Content.
This article may be used for research, teaching, and private study purposes. Any
substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,
systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &

Conditions of access and use can be found at http://www.tandfonline.com/page/terms-
and-conditions

Journal of Asian Natural Products Research
Vol. 13, No. 8, August 2011, 744–748
Irisdichotins A–C, three new flavonoid glycosides from
the rhizomes of Iris dichotoma Pall.
Long Huanga, Wen-Hui Mab, Yan-Ze Liua, Jun-Shan Yanga,
Yong Penga and Pei-Gen Xiaoa*
aInstitute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union
Medical College, Beijing 100193, China; Shanghai Micronmr Information Technology Co., Ltd.,
Shanghai 200437, China
b
(Received 15 February 2011; final version received 10 May 2011)
Three new compounds including one flavonol glycoside, irisdichotin A (1), and two
flavanonol glycosides, irisdichotins B (2) and C (3), wereisolatedfromtherhizomesof Iris
dichotoma Pall. Their structures were elucidated on the basis of spectroscopic methods.
Keywords: Iris dichotoma; irisdichotin A; irisdichotin B; irisdichotin C
1. Introduction
five aromatic protons at dH 6.86 (d, 1H,
J ¼ 2.4 Hz), 6.95 (d, 1H, J ¼ 8.4 Hz), 7.04
(d, 1H, J ¼ 2.4 Hz), 7.75 (dd, 1H, J ¼ 8.4,
2.4 Hz), and 7.79 (d, 1H, J ¼ 2.4 Hz), and
two OH groups at dH 9.09 and 9.67 (s, 1H
each) on aromatic rings, which were very
similar to those of 3,5,30-trihydroxy-7,40-
dimethoxyflavone [3]. In addition, six
proton signals were found in the range of
dH 3.0–4.0, together with the signal at dH
4.86 (d, 1H, J ¼ 7.8 Hz) assigned as the
anomeric proton, which suggested the
existence of a sugar moiety. Comparison
of the NMR spectra of 1 with those of
3,5,30-trihydroxy-7,40-dimethoxyflavone
showed that the OH group at C-5 in 3,5,30-
trihydroxy-7,40-dimethoxyflavone was
replaced by an O-b-D-Glu group in 1, as
confirmed by typical 13C NMR signals at
dC 103.5, 73.6, 75.9, 69.9, 77.6, and 60.9
[4]. The HMBC correlations (Figure 2) of
H-100 at dH 4.86 (d, 1H, J ¼ 7.8 Hz) with
C-5 at dC 157.9 also revealed that the OGlu
group was located at C-5. Acid hydrolysis
of 1 gave glucose, which was identified by
Iris dichotoma Pall. (Iridaceae) is a
perennial herb that is native to China. Its
rhizomes are commonly used in Chinese
folk medicine for clearing heat and
detoxifying, eliminating phlegm, swelling,
and pain in the throat [1]. Several
flavonoids had been previously reported
from the rhizomes of I. dichotoma [2].
To find potential drug leads, the chemical
constituents of I. dichotoma were further
investigated. This paper deals with the
isolation and structural elucidation of three
new flavonoid glycosides, irisdichotins
A–C (1–3; Figure 1).
2. Results and discussion
Irisdichotin A (1), yellow powder, had
molecular formula C23H24O12 on the basis
of HR-ESI-MS data (m/z 493.1352,
[M þ H]þ). The IR spectrum indicated
the presence of hydroxyl (3350 cm21) and
carbonyl (1665 cm21). The 1H NMR
spectrum (Table 1) showed two MeO
groups at dH 3.90 (s, 3H) and 3.86 (s, 3H),
*Corresponding author. Email: xiaopg@public.bta.net.cn
ISSN 1028-6020 print/ISSN 1477-2213 online
q 2011 Taylor & Francis
DOI: 10.1080/10286020.2011.587806
http://www.informaworld.com

Journal of Asian Natural Products Research
745
R3
3'
OMe
R4
4'
2'
1'
MeO
O
O
8
R2O
O
OH
5'
7
2
3
9
10
6'
6
4
OH
OH
5
OR
OR1
O
R1
D-Glc Me OMe OH
Me D-Glc OH
R2 R3 R4
1 R = D-Glc
2
3
H
Figure 1. Structures of compounds 1–3.
comparing with authentic sample. The
assignment of OH group of B ring was
deduced from HMBC correlations
between OH-40 at dH 9.67 and C-50 at dC
115.5, C-30 at 148.5 and C-40 at 147.4.
On the other hand, the correlation between
the methoxyl at dH 3.86 and C-30 at dC
148.5 suggested that the MeO group was
attached at C-30 (Figure 2). Thus, the
structure of 1 was elucidated as 3,40-
dihydroxy-7,30-dimethoxyflavonol-5-O-b-
D-glucopyranoside (Figure 1).
according to the HR-ESI-MS data (m/z
517.1349 [M þ Na]þ). The UV, IR, and
NMR spectral data of 2 were similar to
those of 1. Comparison of the 13C NMR and
DEPT spectra of 2 with those of 1 revealed
that the tetrasubstituted double bond at
C-2,3 in 1 was replaced by two methine
1
carbons in 2, as confirmed by H NMR
signals at dH 5.04 (d, 1H, J ¼ 12.0Hz, H-2)
and 4.47 (dd, 1H, J ¼ 12.0, 4.8 Hz, H-3).
The circular dichroism (CD) spectrum of 2,
which showed a positive Cotton effect in
the region of 334 nm and a negative effect at
300 nm, established the R configuration at
Irisdichotin B (2), yellow powder,
had the molecular formula C23H26O12
Table 1. 1H NMR spectral data of 1–3 (600 MHz, in DMSO at 27o, d in ppm, J in Hz).
Position
1
2
3
H-2
H-3
5.04 (d, J ¼ 12.0)
4.47 (dd, J ¼ 12.0, 4.8)
6.28 (d, J ¼ 2.4)
6.48 (d, J ¼ 2.4)
7.10 (d, J ¼ 1.8)
5.04 (d, J ¼ 12.0)
4.41 (dd, J ¼ 12.0, 4.8)
6.48 (d, J ¼ 2.4)
6.27 (d, J ¼ 2.4)
7.32 (d, J ¼ 9.0)
6.79 (d, J ¼ 9.0)
6.79 (d, J ¼ 9.0)
7.32 (d, J ¼ 9.0)
3.78 (s)
H-6
H-8
6.86 (d, J ¼ 2.4)
7.04 (d, J ¼ 2.4)
7.79 (d, J ¼ 2.4)
H-20
H-30
H-50
6.95 (d, J ¼ 8.4)
6.79 (d, J ¼ 8.4)
H-60
7.75 (dd, J ¼ 8.4, 2.4)
6.92 (dd, J ¼ 8.4, 1.8)
MeO-5
MeO-7
MeO-30
HO-40
HO-3
Glucose
H-100
H-200
H-300
H-400
H-500
H-600
3.90 (s)
3.86 (s)
9.67 (s)
9.09 (s)
3.79 (s)
3.78 (s)
9.08 (s)
5.41 (d, J ¼ 4.8)
9.53 (s)
5.42 (d, J ¼ 4.8)
4.86 (d, J ¼ 7.8)
3.42 (m)
3.33 (m)
3.19 (m)
3.51 (m)
3.77 (m)
4.87 (d, J ¼ 7.2)
4.87 (d, J ¼ 7.8)
3.41 (m)
3.37 (m)
3.43 (m)
3.35 (m)
3.22 (m)
3.46 (m)
3.77 (m)
3.17 (m)
3.48 (m)
3.75 (m)

746
L. Huang et al.
as 3b,40-dihydroxy-5-methoxyflavonone-
7-O-b-D-glucopyranoside.
OCH3
O
O
H3CO
OH
3. Experimental
OH
3.1 General experimental procedures
HO
HO
HO
O
O
Optical rotations were measured on a
JASCO DIP-360 digital polarimeter. UV
spectra were recorded on a PGENRAL
UV-T6 spectrophotometer. IR spectra
were recorded on a SHIMADZU FTIR-
8400s spectrometer. 1H and 13C NMR
spectra (DMSO-d6) were recorded on a
Bruker Avance-600 instrument, and
chemical shifts are given in d (ppm) with
tetramethylsilane as an internal standard.
CD spectra were recorded on a JASCO
J-815 spectrophotometer. Mass spectra
were obtained using a Thermo LTQ
ORBITRAP XL mass spectrometer (for
ESI and HR-ESI). Preparative HPLC was
carried out with LabAlliance Series 1500
pump and LabAlliance Model 500 variable
wavelength detector with a reversed-phase
column (Alltech Alltima C18, 5 mm,
10 £ 250 mm, at 3.5 1 ml/min with detec-
tion at 260 nm).
H
HO
Figure 2. Key HMBC correlations of 1.
the C-2 position [5]. The coupling constant
between H-2 and H-3 (J ¼ 12.0Hz) also
indicated the stereochemistry of C-3 to be R
[6]. Finally, the structure of2 was elucidated
as 3b,40-dihydroxy-7,30-dimethoxyflavo-
none-5-O-b-D-glucopyranoside.
Irisdichotin C (3), white powder, had
the molecular formula C22H24O11 accord-
ing to the HR-ESI-MS data (m/z 487.1224
[M þ Na]þ). Comparison of the H and
1
13C NMR spectral data of 3 with those of 2
indicated that the differences between two
compounds were the locations of methoxy
and the sugar moiety at A-ring, and the
substituent groups at B-ring. AA0BB0 spin
system, which was exhibited at dH 7.32
(d, 2H, J ¼ 9.0 Hz) and 6.79 (d, 2H,
J ¼ 9.0 Hz), and the HMBC correlation of
OH at dH 9.53 with C-40 at dC 157.7
suggested that the OH group was attached
to C-40. The OMe group was attached to
C-5, based on HMBC correlations between
OMe at dH 3.78 and C-5 at dC 165.6, as
well as between H-6 at dH 6.48 and C-5
(Figure 3). The Glu group was attached to
C-7, according to the HMBC correlations
between H-100 at dH 4.87 and C-7 at dC
159.6, and between H-8 at dH 6.27 and
C-7. Finally, the structure was elucidated
3.2 Plant material
The rhizomes of I. dichotoma were
collected at Jiufeng Mountain in Beijing,
China, in April2009, and identified byProf.
Pei-Gen Xiao, Institute of Medicinal Plant
Development, Chinese Academy of Medi-
cal Sciences and Peking Union Medical
College. A voucher specimen (Bj090412)
has been deposited at the Institute of
Medicinal Plant Development, Chinese
Academy of Medical Sciences and Peking
Union Medical College, Beijing, China.
OH
HO
3.3 Extraction and isolation
O
O
O
O
HO
HO
The air-dried rhizomes of I. dichotoma
(5 kg) were refluxed with 90% EtOH
(3 £ 40l, 2 h each). The extracts were
concentrated under reduced pressure to
syrup. The syrup was suspended in H2O
HO
H
OH
OCH3
Figure 3. Key HMBC correlations of 3.

Journal of Asian Natural Products Research
747
Table 2. 13C NMR spectral data of 1–3
(150 MHz, in DMSO at 278; d in ppm).
(6l), followed by successive partitioning
with petroleum ether, AcOEt, and BuOH.
The BuOH extract (326.3g) was subjected
to column chromatography (CC; SiO2;
CHCl3/MeOH/H2O: 100:1:1 to 10:5:1) to
afford 12 fractions (Frs. 1 , 12). Fr. 4
(21.1 g) was further subjected to repeated
CC (CHCl3/MeOH/H2O: 50:3:1 to 10:3:1),
and then with preparative HPLC (Alltima
C18, 5 mm, 10 £ 250 mm, MeOH/H2O
47:53, flow rate 3.6 ml/min) to give
compound 1 (7 mg) and compound 2
(5.6 mg). Fr. 11 (23.3 g) was further
subjected to repeated CC (CHCl3/
MeOH/H2O: 99:1 to 6:4:1) to afford 15
fractions (Fr. 11.1 , 11.15). Fr. 11.12
(9.8 g), eluted with CHCl3/MeOH/H2O
(15:3:1), was subjected to repeated CC
(SiO2; CHCl3/MeOH/H2O 15:3:1), and then
with prep. HPLC (MeOH/H2O 50:50; flow
rate 5 ml/min) to give compound 3 (5 mg).
Position
1
2
3
C-2
C-3
C-4
C-5
C-6
C-7
C-8
C-9
C-10
C-10
C-20
C-30
C-40
C-50
C-60
MeO-5
MeO-7
MeO-30
C-100
C-200
C-300
C-400
C-500
C-600
143.6 (s)
137.7 (s)
171.7 (s)
157.9 (s)
102.3 (d)
163.4 (s)
95.6 (d)
157.2 (s)
107.3 (s)
121.4 (s)
111.5 (d)
148.5 (s)
147.4 (s)
115.5 (d)
122.0 (s)
82.8 (d)
72.5 (d)
191.3 (s)
159.5 (s)
97.0 (d)
82.5 (d)
72.6 (d)
191.3 (s)
165.6 (s)
97.0 (d)
159.6 (s)
95.4 (d)
163.5 (s)
104.4 (s)
127.5 (s)
114.8 (d)
129.3 (d)
157.7 (s)
129.3 (d)
114.8 (s)
55.8 (q)
165.6 (s)
95.4 (d)
163.7 (s)
104.4 (s)
128.0 (s)
115.0 (d)
147.3 (s)
146.9 (s)
112.2 (d)
121.0 (s)
56.0 (q)
60.8 (q)
103.5 (d)
73.6 (d)
75.9 (d)
69.9 (d)
77.6 (d)
60.9 (t)
55.8 (q)
55.7 (q)
101.6 (d)
73.3 (d)
76.2 (d)
69.7 (d)
77.4 (d)
60.7 (t)
101.6 (d)
73.3 (d)
76.2 (d)
69.8 (d)
77.4 (d)
60.8 (t)
3.3.1 3,40-Dihydroxy-7,30-dimethoxy-
flavonol-5-O-b-D-glucopyranoside (1)
3.3.1.1 Yellow powder. [a]2D5 274.8 (c
0.05, MeOH). UV (MeOH) lmax (log1) 205
(4.68), 252 (4.33), 367 (4.36) nm; IR (KBr)
3.3.3 3b,40-Dihydroxy-5-methoxy-
flavonone-7-O-b-D-glucopyranoside (3)
n
1616, 1541, 1506, 1456, 1421, 1300, 1271,
max cm21: 3320 (br), 2938, 2376, 1665,
3.3.3.1 White powder. [a ]2D5 273.3 (c
0.12, MeOH). UV (MeOH) lmax (log 1)
201 (4.75), 227 (4.76), 282 (4.55) nm; CD
(MeOH) D1300 nm 22.356, D1334 nm 1.419;
IR (KBr) nmax cm21: 3350 (br), 2955,
2925, 2881, 1690, 1616, 1595, 1456, 1261,
1170, 1103. 1H and 13C NMR spectral data
are shown in Tables 1 and 2. HR-ESI-MS:
m/z 487.1224 [M þ Na]þ (calcd for
C22H24O11Na, 487.1216).
1
1213, 1103, 1078, 993. H and 13C NMR
spectral data are shown in Tables 1 and 2.
HR-ESI-MS: m/z 493.1352 [M þ H]þ
(calcd for C23H25O12, 493.1346).
3.3.2 3b,40-Dihydroxy-7,30-dimethoxy-
flavonone-5-O-b-D-glucopyranoside (2)
3.3.2.1 Yellow powder. [a]2D5 256.4 (c
0.05, MeOH). UV (MeOH) lmax (log 1)
202 (4.82), 227 (4.53), 283 (4.40) nm; CD
(MeOH) D1300 nm 22.295, D1334 nm 1.252;
IR (KBr) nmax cm21: 3350 (br), 2952,
2922, 2902, 1681, 1612, 1573, 1440, 1257,
1163, 1103. 1H and 13C NMR spectral data
are shown in Tables 1 and 2. HR-ESI-MS:
m/z 517.1349 [M þ Na]þ (calcd for
C23H26O12Na, 517.1322).
3.4 Acid hydrolysis of compounds 1, 2,
and 3
Each compound (3 mg) dissolved in 3 ml
of HCl–H2O–EtOH (2:1:2) was stirred at
808C for 4 h. The hydrolysate was parti-
tioned between EtOAc and H2O. The
aqueous layer was analyzed by silica gel
TLC [CHCl3–MeOH–H2O (8:5:1)] and

748
L. Huang et al.
[2] Y.Q. Li, Y.R. Lu, and L.X. Wei, Acta
Pharmacol. Sin. 21, 836 (1986).
[3] H. Dong, Y.L. Gou, S.G. Cao, S.X. Chen,
K.Y. Sim, S.H. Goh, and R.M. Kini,
Phytochemistry 50, 899 (1999).
identified by comparing with authentic
samples, and the result showed that the
sugar was glucose.
[4] A.H. Abou-Donia, S.M. Toaima, H.M.
Hammoda, E. Shawky, E. Kinoshita, and
H. Takayama, Chem. Biodivers. 5, 332
(2008).
[5] J.L. Ingham, S. Tahara, and S.Z. Dziedzic,
J. Nat. Prod. 49, 631 (1986).
[6] T.S. Wu, M.Y. Hsu, P.C. Kuo, A.G. Damu,
C.R. Su, C.Y. Li, and H.C. Chang, J. Nat.
Prod. 66, 1207 (2003).
References
[1] G.P. Zhao, S. Dai, and R.S. Chen, in
Zhongyao Da Cidian (The Dictionary of
Chinese Crude Drugs), edited by Nanjing
University of Chinese Medicine (Shanghai
Science and Technology Press, Shanghai,
2006), p. 1027.