Flavonoids from the seeds of Oroxylum indicum and their anti-inflammatory and cytotoxic activities

Article abstract of DOI:10.1016/j.phytol.2019.05.003

Two new flavonoid glycosides, named oroxin C (1)and oroxin D (scutellarein 4'-methyl ether 7-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside, 2), together with eight known flavonoids (3–10), were isolated from the seeds of Oroxylum indicum. Their structures were elucidated unambiguously by spectroscopic techniques and chemical methods. Anti-inflammatory and cytotoxic activities of all the isolated compounds were evaluated. Chrysin (3)and chrysin-6-C-β-D-glucopyranosyl-8-C-α-L-arabinopyranoside (10)showed moderate inhibitory effects aganist the LPS-induced NO production in murine RAW264.7 macrophages with IC₅₀ values of 18.63 ± 0.91 and 28.69 ± 0.43 μM, respectively. Chrysin (3)exhibited weak cytotoxic activity aganist A549, HepG2 and SW480 human cancer cell lines with IC₅₀ values of 40.88 ± 3.85, 50.55 ± 2.59 and 91.60 ± 4.27 μM, respectively.

Full text of DOI:10.1016/j.phytol.2019.05.003

Phytochemistry Letters 32 (2019) 66–69
Contents lists available at ScienceDirect
Phytochemistry Letters
journal homepage: www.elsevier.com/locate/phytol
Flavonoids from the seeds of Oroxylum indicum and their anti-inflammatory
and cytotoxic activities
Bing-Lan Wu , Zhou-Wei Wua,b, Fan Yanga,b, Xiao-Fei Shen , Lun Wang , Bin Chen , Fu Li ,
a,b
c
a,⁎
a
a
a,⁎
Ming-Kui Wang
a
Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province,
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
b
c
University of Chinese Academy of Sciences, Beijing 100049, China
Key Laboratory of Birth Defects and Related Diseases of Women and Children (Ministry of Education), Department of Paediatrics, West China Second University Hospital,
Sichuan University, Chengdu 610041, China
A R T I C L E I N F O
A B S T R A C T
Keywords:
Two new flavonoid glycosides, named oroxin C (1) and oroxin D (scutellarein 4'-methyl ether 7-O-β-D-gluco-
pyranosyl-(1→6)-β-D-glucopyranoside, 2), together with eight known flavonoids (3–10), were isolated from the
seeds of Oroxylum indicum. Their structures were elucidated unambiguously by spectroscopic techniques and
chemical methods. Anti-inflammatory and cytotoxic activities of all the isolated compounds were evaluated.
Chrysin (3) and chrysin-6-C-β-D-glucopyranosyl-8-C-α-L-arabinopyranoside (10) showed moderate inhibitory
effects aganist the LPS-induced NO production in murine RAW264.7 macrophages with IC50 values of
Oroxylum indicum
Flavonoid glycosides
Anti-inflammatory activity
Cytotoxic activity
1
8.63 ± 0.91 and 28.69 ± 0.43 μM, respectively. Chrysin (3) exhibited weak cytotoxic activity aganist A549,
HepG2 and SW480 human cancer cell lines with IC50 values of 40.88 ± 3.85, 50.55 ± 2.59 and 91.60 ± 4.27
μM, respectively.
1
. Introduction
et al., 2016, 2015). As a part of a program to search for undescribed and
bioactive compounds from traditional Chinese medicines, a methanol
Oroxylum indicum Vent. (Bignoniaceae) is a small or medium sized
extract of the seeds of O. indicum was investigated. This procedure led
to the isolation of two new flavonoids glycosides (1 and 2), named
oroxin C and oroxin D, together with eight known ones (3–10). In this
paper, we report the isolation and structural analysis of these flavo-
noids, along with the assessment of their anti-inflammatory and cyto-
toxic activities.
deciduous tree growing throughout Asia continent, and used as eth-
nomedicine in China, Japan and other Asian countries. The seeds of this
plant, named as “Mu Hu Die” in Chinese, have been used as an an-
algesic, antitussive and anti-inflammatory agent for the treatment of
cough, bronchitis and other diseases (Dev et al., 2010; Lalrinzuali et al.,
2
018). Modern pharmacological studies suggested that this plant pos-
sessed anticancer (Nakahara et al., 2001; Roy et al., 2007; Ahad et al.,
014), anti-inflammatory (Doshi et al., 2012), antimicrobial (Kumar
2. Results and discussion
2
et al., 2011), antioxidant (Siriwatanametanon et al., 2010) and im-
munostimulant activities (Zaveri et al., 2006; Ahad et al., 2014).
According to previous studies, O. indicum is a source rich in flavo-
noids, and the major bioactive constituents in the seeds of O. indicum
included chrysin, baicalein, baicalein-7-O-β-D-glucoside (oroxin A) and
baicalein-7-O-diglucoside (oroxin B) (Yang et al., 2006; Krüger and
Ganzera, 2012). In recent years, more attention has been paid to
chrysin, baicalein and their glycosides due to their variety of biological
activities, such as anti-inflammatory, antioxidant, anti-allergic and anti-
cancer activities (Nijveldt et al., 2001; Chen et al., 2003; Lalrinzuali
Two new flavonoid glycosides, oroxin C (1) and oroxin D (2)
(Fig. 1), together with eight known ones were isolated from the seeds of
O. indicum. The known compounds were confirmed as chrysin (3)
(Majumdar et al., 2010), oroxin B (4) (Cheng and Chao, 1964), chrysin-
7-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (5) (Rosa and
Stefano, 1983), scutellarein-7-O-β-D-glucopyranosyl-(1→6)-β-D-gluco-
pyranoside (6) (Yan et al., 2001), oroxin A (7) (Cheng and Chao, 1964),
quercetin 7-O-β-D-glucopyranoside (8) (Markham and Ternai, 1976;
Qin et al., 2003), quercetin-3-O-α-L-arabinoside (9) (Bilia et al., 1996)
and chrysin-6-C-β-D-glucopyranosyl-8-C-α-L-arabinopyranoside (10)
⁎
Corresponding authors.
E-mail addresses: wanglun@cib.ac.cn (L. Wang), wangmk@cib.ac.cn (M.-K. Wang).
https://doi.org/10.1016/j.phytol.2019.05.003
Received 30 January 2019; Received in revised form 26 April 2019; Accepted 7 May 2019
1874-3900/ © 2019 Phytochemical Society of Europe. Published by Elsevier Ltd. All rights reserved.

B.-L. Wu, et al.
Phytochemistry Letters 32 (2019) 66–69
Fig. 1. Structures of compounds 1 and 2.
(
Zhou and Yang, 2000), based on NMR data and mass spectrometric
observed. The 13C NMR, DEPT, and HSQC spectra exhibited 28 carbon
signals, of which 16 carbons were assigned to the aglycone moiety, and
12 carbons for two sugar units. Comparison of the NMR data of 2 with
analysis, as well as by comparison of the spectral data with those re-
ported (Fig. S1).
Compound 1 was isolated as a yellow amorphous powder. The
those
of
scutellarein
7-O-β-D-glucopyranosyl-(1→6)-β-
molecular formula C33
H
40
O
20 of 1 was inferred from its HRESIMS data
D–glucopyranoside (6) indicated that these two compounds shared the
same sugar chain linked to C-7 of the aglycone, and a similar aglycone
except for the presence of one methoxyl group at C-4' in 2 instead of one
hydroxyl group at C-4' in 6. This was further confirmed by HMBC
+
+
(
m/z 757.2167 [M+H] , calcd for C33
H
41
O
20 , 757.2186). The IR
−
1
spectrum indicated the presence of hydroxyl (3286 cm ), carbonyl
−
1
−1
(
1666 cm ) and aromatic groups (1613, 1585, 1473 cm ). UV ab-
sorptions maxima at λmax 280 and 321 nm were indicative of flavanone
correlations of δ
H
3.85 (OMe-4') with δ
C
162.4 (C-4') and δ 8.06 (H-2',
H
1
3
structure. The C NMR, DEPT, and HSQC spectra revealed the presence
of 33 carbon resonances, including three methylenes, twenty-two me-
thines, one carbonyl and seven quaternary carbons, of which 15 car-
bons were attributed to a flavonoid skeleton and 18 carbons were as-
6') with δ 162.4 (C-4') (Fig. 2). Acid hydrolysis of 2 gave D-glucose.
C
The β-configuration of glucose was determined by large J values
(> 7.0 Hz) of the anomeric protons. The linkage of the sugar residues
was deduced from the HMBC correlations of δ
H
4.22 (H-1”') with δ
C
1
signed to the sugar moieties. The H NMR spectrum of 1 displayed the
69.6 (C-6”) and δ
H
5.03 (H-1”) with δ 151.4 (C-7). The structure of
C
characteristic signals at δ
H
7.08 (1H, s, H-3) and δ
H
6.98 (1H, s, H-8),
compound 2 was further verified by extensive 2D-NMR experiments.
Consequently, compound 2 was identified as scutellarein 4'-methyl
ether 7-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside, and named
as oroxin D.
two multiplets proton signals at δ
H
8.10 (2H, m, H-2', 6') and δ 7.62
H
(
3H, m, H-3', 4', 5') for a flavonoid skeleton. Furthermore, signals for
hydroxyl group at δ
H
12.10 (1H, s, 5-OH) and δ
H
8.57 (1H, s, 6-OH),
4.67 (1H, d, J
three anomeric proton at δ
H
5.03 (1H, d, J = 7.2 Hz), δ
H
The isolated compounds 1–10 were tested for their cytotoxicities
against A-549, HepG2, and SW480 human cell lines, with taxol as the
positive control (Table 2). Among the tested compounds, compound 3
exhibited weak cytotoxic activity aganist A549, HepG2 and SW480
human cancer cell lines with IC50 values of 40.88 ± 3.85,
50.55 ± 2.59 and 91.60 ± 4.27 μM, respectively, while other com-
pounds displayed no cytotoxic activity (IC50 > 100 μM).
=
7.3 Hz) and δ 4.22 (1H, d, J = 7.6 Hz) were observed. The above
H
NMR data suggested that compound 1 was a flavonoid glycoside. A
detailed comparison of the NMR data of 1 with those of co-occurring
known compounds oroxin B (4) and oroxin A (7) indicated that they
shared the same aglycone. The main difference occurred in the sugar
1
3
chain linked to C-7 of the aglycone. The C NMR spectral data of the
sugar moieties of 1 were similar to those of 4 except the presence of an
additional β-glucopyranosyl unit at C-6 of Glc2 unit. This was further
All isolated compounds were evaluated for their inhibition of LPS-
induced NO production in RAW264.7 macrophages, with BAY11-7082
as the positive control (Table 3). Compounds 3 and 10 showed mod-
erate inhibitory effects on the production of NO with IC50 values of
18.63 ± 0.91 and 28.69 ± 0.43 μM, respectively. While other com-
pounds displayed no anti-inflammatory activity (IC50 > 50 μM).
confirmed by the HMBC corrections (Fig. 2) of δ
H
4.67 (H-1””) with δ
C
6
6.9 (C-6”'), δ
H
4.22 (H-1”') with δ
C
69.2 (C-6”) and δ
H
5.03 (H-1”) with
δ 151.6 (C-7). Acid hydrolysis experiment indicated the sugar residues
C
are D-glucoses. The β-configurations of glucose were assigned based on
3
the large coupling constants ( J1,2 > 7.0 Hz) of their anomeric protons.
The structure of compound 1 was further verified by extensive 2D-NMR
experiments. Accordingly, compound 1 was elucidated as baicalein 7-O-
β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl-(1→6)-β-D-glucopyr-
anoside, and named as oroxin C.
3
. Experimental
3.1. General
Compound 2 was obtained as a yellow, amorphous powder. Its
Optical rotations were measured by using a Perkin-Elmer 341 po-
molecular formula was C28
H
32
O
16, which was determined by HRESIMS
larimeter at room temperature. IR spectra were identified on a Perkin
Elmer 1725X-FT spectrometer with KBr disks. NMR spectra were re-
gistered on a Bruker Avance-400 spectrometer. UV spectra were run on
a Shimadzu UV-2550 spectrophotometer. NMR spectra were recorded
in ppm with TMS as internal standard, and coupling constants (J) are in
Hz. High resolution electrospray ionization mass spectrometry (HR-ESI-
MS) were performed a MicroTOF-QII mass spectrometer. Analytical
HPLC was carried out on Prominence LC-20AT with a model SPD-M20A
detector and a Welch Ultimate C18 column (250 mm × 4.60 mm, 5 μm).
Preparative HPLC was carried out on P3000 with a UV 3000 detector
+
+
at m/z 625.1756 ([M+H] , calcd for C28
H
33
O
16 , 625.1763). The IR
−1
spectrum displayed absorption bands of hydroxyl groups (3415 cm ),
-
1
−1
carbonyl (1651 cm ) and aromatic groups (1605, 1582, 1470 cm ).
The UV spectrum demonstrated absorption maxima at 284 and 340 nm,
1
featuring a flavonoid. The H NMR spectrum of 2 showed two doublets
at δ
H
8.06 (2H, d, J = 8.8 Hz, H-2', H-6') and δ
H
7.18 (2H, d, J =
ˊ
8
.8 Hz, H-3', H-5') suggesting the presence of an AAʹXXʹ spin system in
the B ring. Singlets at δ
to H-8 and H-3 on the basis of HSQC and HMBC spectra. Two anomeric
proton signals at δ 5.03 (1H, d, J = 7.3 Hz) and δ 4.22 (1H, d, J =
.7 Hz), as well as one methoxyl group signal at δ 3.85 (3H, s) were
H
7.14 (1H, s) and δ
H
6.88 (1H, s) were assigned
H
H
(
Beijing ChuangXin Tong Heng Science and Technology Co. Ltd) and
7
H
Ultimate C18 column (250 mm × 30 mm, 10 μm). Silica gel (100–200
Fig. 2. Key HMBC (H→C) correlations of
compounds 1 and 2.
67

B.-L. Wu, et al.
Phytochemistry Letters 32 (2019) 66–69
mesh and 200–300 mesh, Qingdao Marine Chemical Factory) and RP-
Table 1
1
H NMR (400 MHz) and 13C NMR (100 MHz) data of compounds 1 and 2 in
C
18 (150–200 mesh, Merck, Germany) were used for column chroma-
DMSO-d
Position
6
(δ in ppm, J in Hz).
tography (CC). TLC was carried out on precoated silica gel GF254 plates
and spots were visualised under UV light.
1
ꢀ
2
ꢀ
δ
H
δ
C
δ
H
δ
C
3
.2. Plant material
2
3
4
5
6
7
8
9
163.7
104.6
182.7
146.5
130.5
151.6
94.2
163.7
103.1
182.5
146.5
130.4
151.4
94.5
6.98 (1H, s)
7.07 (1H, s)
6.88 (1H, s)
The seeds of O. indicum were purchased from Sichuan Neautus
Traditional Chinese Medicine Co. Ltd. People's Republic of China,
which were collected from, Guangxi province, People’s Republic of
China, in February 2017, and were identified by Prof. W.K. Bao of
Chengdu Institute of Biology, Chinese Academy of Sciences. A voucher
specimen (CIB-A-423) has been stored at the Laboratory of
Phytochemistry, Chengdu Institute of Biology, Chinese Academy of
Sciences. The purity (> 98%) of compounds 1–10used for biological
7.14 (1H, s)
149.3
106.3
130.8
126.5
129.3
132.2
101.1
72.1
149.2
105.9
122.9
128.4
114.9
162.4
101.1
73.2
1
1
2
0
'
', 6'
8.10 (2H, m)
7.62 (2H, m)
7.62 (1H, m)
5.03 (1H, d, 7.2)
3.15 (1H, m)
3.42 (1H, m)
3.23 (1H, m)
3.34 (1H, m)
3.68 (1H, m)
8.06 (2H, d, 8.8)
7.18 (2H, d, 8.8)
3',5'
4
'
analysis was determined by HPLC-UV(DAD) with MeCN–H O (1%
2
Glc1-1”
5.03 (1H, d, 7.3)
3.38 (1H, m)
3.17 (1H, m)
3.13 (1H, m)
3.78 (1H, m)
3.65 (1H, m)
4.05 (1H, d, 11.1)
4.22 (1H, d, 7.7)
3.32 (1H, m)
3.09 (1H, m)
3.21 (1H, t, 9.4)
3.18 (1H, m)
3.34 (1H, m)
acetic acid), a Welch Ultimate C18 column (250 mm × 4.60 mm, 5 μm)
was used and the flow rate was set at 0.8 ml/min.
2
3
4
5
6
”
”
”
”
”
73.3
76.8
70.3
70.3
75.5
75.6
3.3. Extraction and isolation
69.2
69.6
4
.03 (1H, d, 11.2)
Glc2-1”'
4.22 (1H, d, 7.6)
3.16 (1H, m)
3.41 (1H, m)
3.68 (1H, m)
3.34 (1H, m)
3.65 (2H, m)
103.9
72.5
73.5
70.1
75.5
66.9
103.8
75.7
73.6
69.8
77.3
61.3
The dried and powdered seeds of O. indicum (50 kg) were extracted
2
3
4
”'
”'
”'
with 70% MeOH three times (300 L, 2d, each) at room temperature. The
solvent was evaporated, and the residue was suspended in water and
then extracted with n-BuOH, to yield water extract and n-BuOH extract.
The water solution was chromatographed on HPD-100 macroporous
5”'
6”'
3
.66 (1H, m)
resin, eluting with EtOH-H O (0:100, 30:70, 80:20), to give two frac-
2
Glc3-1””
4.67 (1H, d, 7.3)
3.44 (1H, m)
3.32 (1H, m)
3.67 (1H, m)
3.17 (1H, m)
3.44 (1H, m)
98.5
73.2
75.1
69.7
76.8
60.6
tions (Fr.1 and Fr.2). Fraction 1 (1.3 kg) was depurated by reversed
phase preparative HPLC using an isocratic solvent system of
2
3
””
””
MeOH–H
2
O (0.5% acetic acid, 50:50), to obtain six fractions (Fr.1a-
4””
5
6
””
””
Fr.1f). Fr.1c and Fr.1f were recrystallized from MeOH to afford com-
pounds 4 (130 g) and 7 (115 g). Fr.1d and Fr.1e were further purified by
3
.50 (1H, m)
preparative HPLC with MeCN–H O (0.5% acetic acid, 30:70, v/v) as the
2
4
'-OMe
ꢀ
ꢀ
3.85 (3H, s)
12.68 (1H, s)
8.53 (1H, s)
55.6
eluent to get 5 (t
26.1 min, 200 mg). Fr.1a was purified by reversed phase preparative
HPLC and eluted with MeCN-H O (0.5% acetic acid, 21:79, v/v) to
afford three subfractions (Fr.1a1-Fr.1a3). Fr.1a1 (1.5 g) and Fr.1a3
2.35 g) were further purified by reversed phase preparative HPLC with
MeCN-H O (0.5% acetic acid, 21:79, v/v) to give compounds 10 (t
65.7 min, 47 mg), 8 (t =26.2 min, 30 mg) and 1 (t =28 min,
0 mg). Fr.1a2 (10.3 g) was subjected to a silica gel column chroma-
tography using gradient solvents of CH Cl −MeOH–H O (7:1:0.1,
:1:0.1, 1:1:0.1, v/v) to give two major fractions (Fr.1a2a-Fr.1a2b).
Fr.1a2a was further purified by reversed phase preparative HPLC with
MeCN-H O (0.5% acetic acid, 20:80, v/v) as the eluent to afford 6 (t
65.7 min, 40 mg). Fraction 2 (820 g) was chromatographed on silica
gel with EtOAc−MeOH–H (10:1:0.2, 8:1:0.2, 6:1:0.2, 5:1:0.2,
:1:0.2, 1:1:0.2, v/v) to give seven fractions, Fr.2a–Fr.2 g. Fr.2b was
recrystallized by MeOH to give compound 3 (15 g).
R
=38.9 min, 15 g), 9 (t
R
=34.5 min, 600 mg), 2 (t
R
5-OH
6-OH
12.10 (1H, s)
8.57 (1H, s)
=
2
Table 2
(
Cytotoxicity of Compound 3 against A549, HepG2 and SW480 cell lines
2
R
(
mean ± SD, n = 3).
=
R
R
6
Compound
IC50 (μM)
2
2
2
A549
HepG2
SW480
4
3
40.88 ± 3.85
50.55 ± 2.59
91.6 ± 4.27
a
2
R
Taxol
10.14 ± 0.71 nM
12.84 ± 0.58 nM
20.74 ± 1.87 nM
=
a
Positive control.
2
O
3
Table 3
Inhibitory effects of compounds 3 and 10 against LPS-
induced NO production in RAW-264.7 macrophages
(mean ± SD, n = 3).
3.3.1. oroxin C (1)
2
0
Yellow, amorphous powder; [α] −72.0 (c 0.1, MeOH); IR (KBr)
Compounds
IC50 (μM)
D
−
1
ν
max 3286, 1666, 1613, 1585, and 1473 cm ; UV (MeOH) λmax (log ε)
3
18.63 ± 0.91
28.69 ± 0.43
2.99 ± 0.46
1
13
3
21 (2.16) nm, λmax (log ε) 280 (2.40) nm; for H and C NMR data,
+ +
1
0
a
see Table 1; HRESIMS m/z 757.2167 [M+H] (calcd for C33
H
41
O
20
,
BAY11-7082
7
57.2186).
a
Positive control.
3
.3.2. oroxin D (2)
3
.4. Acid hydrolysis of compounds 1 and 2
2
0
Yellow, amorphous powder; [α] −170.0 (c 0.1, MeOH); IR (KBr)
D
−
1
ν
max 3415, 2924, 1651, 1605, 1470, 1053 cm ; UV (MeOH) λmax (log
The absolute configurations of the sugar moieties were determined
using the method previously reported (Li et al., 2017). Compounds 1
and 2 (each 5 mg) was heated with 5% H SO (3 ml) under reflux for
5 h. The reaction mixture was diluted with H O and then extracted with
1
13
ε) 340 (2.21) nm, λmax (log ε) 284 (2.19) nm; for H and C NMR data,
+
+
see Table 1; HRESIMS m/z 625.1756 [M+H] (calcd for C28
H
33
O
16
,
2
4
6
25.1763).
2
68

B.-L. Wu, et al.
Phytochemistry Letters 32 (2019) 66–69
EtOAc three times. The H
2
O layer was neutralized with Ba(OH)
2
, fil-
Pharm. Sin. 11, 762–767.
Dev, L.R., Anurag, M., Rajiv, G., 2010. Oroxylum indicum: a review. Pharmacognosy 2,
tered and subjected to TLC analysis with authentic glucose sample. The
3
04–310.
optical rotation of the water solution was determined to be [α]
Doshi, K., Ilanchezhian, R., Acharya, R., Patel, B.R., Ravishankar, B., 2012. Anti-in-
flammatory activity of root bark and stem bark of Shyonaka. J. Ayurveda Integr. Med.
3, 194–197.
2
0
20
+
51.8 (c 0.018, H
2
O) and [α] +51.2 (c 0.014, H
2
O) for com-
D
D
pounds 1 and 2, indicating the absolute configurations of the glucose in
Gu, X.Y., Shen, X.F., Wang, L., Wu, Z.W., Chen, B., Zhang, G.L., Wang, M.K., 2018.
Bioactive steroidal alkaloids from the fruits of Solanum nigrum. Phytochemistry 147,
compounds 1 and 2 should be in D-form.
1
25–131.
Krüger, A., Ganzera, M., 2012. Oroxylum indicum seeds-analysis of flavonoids by HPLC-
MS. J. Pharm. Biomed. Anal. 70, 553–556.
3.5. Cytotoxicity assay
Kumar, V., Chaurasia, A.K., Naglot, A., Gopalakrishnan, R., Gogoi, B.J., Singh, L.,
Srivastava, R.B., Deka, D.C., 2011. Antioxidant and antimicrobial activities of stem
bark extracts of Oroxylum indicum Vent. (Bignoniaceae): a medicinal plant of north-
eastern India. South Asian J. Exp. Biol. 1, 152–157.
All isolated compounds were evaluated for their cytotoxicity against
A549, HepG2 and SW480 cell lines (obtained from the Shanghai Cell
Bank, Chinese Academy of Sciences). The cytotoxic activities were as-
sayed by using the MTT method in 96 well plates according to the
previous report (Gu et al., 2018).
Lalrinzuali, K., Vabeiryureilai, M., Jagetia, G.C., Lalawmpuii, P.C., 2015. Free radical
scavenging and antioxidant potential of different extracts of Oroxylum indicum in
vitro. Adv. Biomed. Pharm. 2, 120–130.
Lalrinzuali, K., Vabeiryureilai, M., Jagetia, G.C., 2016. Investigation of the anti-in-
flammatory and analgesic activities of ethanol extract of stem bark of Sonapatha
Oroxylum indicum in vivo. Int. J. Inflam. 2016, 1–8.
3.6. Anti-inflammatory activity
Lalrinzuali, K., Vabeiryureilai, M., Jagetia, G.C., 2018. Topical application of stem bark
ethanol extract of Sonapatha, Oroxylum indicum (L.) Kurz accelerates healing of deep
dermal excision wound in Swiss albino mice. J. Ethnopharmacol. 227, 290–299.
Li, F., Yang, F.M., Xin, L., Wang, L., Chen, B., Li, L.H., Wang, M.K., 2017. Cucurbitane
glycosides from the fruit of Siraitia grosvenori and their effects on glucose uptake in
human HepG2 cells in vitro. Food Chem. 228, 567–573.
The anti-inflammatory activity of all compounds was evaluated
based on the reported procedures (Gu et al., 2018).
Conflict of interest
Majumdar, S., Mohanta, B.C., Chowdhury, D.R., Banik, R., Dinda, B., Basak, A., 2010.
Proprotein convertase inhibitory activities of flavonoids isolated from Oroxylum in-
dicum. Curr. Med. Chem. 17, 2049–2058.
The authors declare no conflict of interest.
Acknowledgments
1
3
Markham, K.R., Ternai, B., 1976. C NMR of flavonoids-Ⅱ, flavonoids other then flavone
and flavonol aglycones. Tetrahedron 32, 2607–2612.
Nakahara, K., Onishi, K.M., Ono, H., Yoshida, M., Trakoontivakorn, G., 2001.
Antimutagenic activity against trp-P-1 of the edible Thai plant: Oroxylum indicum
Vent. Biosci. Biotechnol. Biochem. 65, 2358–2360.
This work was supported by Sichuan Science and Technology
Program (2017SZ0020) and West Light Foundation of Chinese
Academy of Sciences (Y7C1031100).
Nijveldt, R., Nood, E., Hoorn, D.E.C., Boelens, P.G., Norren, K., Leeuwen, P.A.M., 2001.
Flavonoids: a review of probable mechanisms of action and potential applications.
Am. J. Clin. Nutr. 74, 418–425.
Qin, B., Wang, H.Q., Zhu, D.Y., 2003. Investigation on the chemical constituents of
Debregeasia longifolia. Nat. Prod. Res. Dev. 15, 21–23.
Appendix A. Supplementary data
Rosa, D.S., Stefano, D.S., 1983. Chrysin 7-gentiobioside from the flowers of Spartium
junceum. Phytochemistry 22, 2323–2324.
Roy, M.K., Nakahara, K., Na, V., Trakoontivakorn, G., Takenaka, M., Isobe, S., Tsushida,
T., 2007. Baicalein, a flavonoid extracted from a methanolic extract of Oroxylum
indicum inhibits proliferation of a cancer cell line in vitro via induction of apoptosis.
Pharmazie 62, 149–153.
Supplementary material related to this article can be found, in the
online version, at doi:https://doi.org/10.1016/j.phytol.2019.05.003.
Siriwatanametanon, N., Fiebich, B.L., Efferth, T., Prieto, J.M., Heinrich, M., 2010.
Traditionally used Thai medicinal plants: in vitro anti-inflammatory, anticancer and
antioxidant activities. J. Ethnopharmacol. 130, 196–207.
References
Ahad, A., Ganni, A.A., Sareer, O., Najm, M.Z., Kausar, A., Mohd, M., Siddiqui, W.A., 2014.
Yan, R.Y., Cao, Y.Y., Chen, C.Y., 2001. Antioxidant flavonoids from the seed of Oroxylum
indicum. Fitoterapia 82, 841–848.
Therapeutic potential of Oroxylum indicum: a review. J. Pharm. Res. Opin. 2,
1
63–172.
Yang, M.H., Zeng, J., Chen, B., Yan, F., 2006. Analysis of flavonoids in seeds of Oroxylum
indicum. Nat. Prod. Res. Dev. 37, 505–508.
Bilia, A.R., Ciampi, L., Mendez, J., Morelli, I., 1996. Phytochemical investigations of
Licania genus. Flavonoids from Licania pyrifolia. Pharm. Acta Helv. 71, 199–204.
Chen, L.J., Games, D.E., Jones, J., 2003. Isolation and identification of four flavonoid
constituents from the seeds of Oroxylum indicum by high-speed counter-current
chromatography. J. Chromatogr. A 988, 95–105.
Zaveri, M., Gohil, P., Jain, S., 2006. Immunostimulant activity of n-butanol fraction of
root bark of Oroxylum indicum Vent. J. Immunotoxicol. 3, 83–99.
Zhou, Z.H., Yang, C.R., 2000. Five new flavonoid glycosides from Scutellaria amoena. Acta
Bot. Yunnan 22, 475–481.
Cheng, C.L., Chao, C.Y., 1964. Two new flavone glucosides oroxin A and oroxin B. Acta
69