New flavonoid glycosides from Xanthium strumarium with their protein tyrosine phosphatase 1B inhibitory activity

Article abstract of DOI:10.1080/10286020.2021.1873957

Two new flavonoid glycosides named 6-hydroxy-3-methoxy-apigenin 7-O-α-?-rhamnopyranoside (1) and 3-hydroxyl-apigenin 8-C-β-?-xylopyranoside (2), along with five known compounds (3-7), were isolated from Xanthium strumarium. Their structures were elucidate

Full text of DOI:10.1080/10286020.2021.1873957

Journal of Asian Natural Products Research
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New flavonoid glycosides from Xanthium
strumarium with their protein tyrosine
phosphatase 1B inhibitory activity
Pei-Jing Jiang, Mei-Jiao Lu, Yi-Yuan Xi, Jun Chen, Ju-Jia Zheng & Xiang-Wei Xu
To cite this article: Pei-Jing Jiang, Mei-Jiao Lu, Yi-Yuan Xi, Jun Chen, Ju-Jia Zheng &
Xiang-Wei Xu (2021): New flavonoid glycosides from Xanthiumꢀstrumarium with their protein
tyrosine phosphatase 1B inhibitory activity, Journal of Asian Natural Products Research, DOI:
10.1080/10286020.2021.1873957
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JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH
https://doi.org/10.1080/10286020.2021.1873957
New flavonoid glycosides from Xanthium strumarium with
their protein tyrosine phosphatase 1B inhibitory activity
a
b
c
a
c
ꢀ
ꢀ
Pei-Jing Jiang , Mei-Jiao Lu , Yi-Yuan Xi , Jun Chen , Ju-Jia Zheng and
Xiang-Wei Xua
aDepartment of Pharmacy, The First People’s Hospital of Yongkang, Yongkang 321300, China;
c
bDepartment of Pharmacy, The People’s Hospital of Jinyun, Jinyun 321400, China; School of
Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
ABSTRACT
ARTICLE HISTORY
Received 15 November 2020
Accepted 5 January 2021
Two new flavonoid glycosides named 6-hydroxy-3-methoxy-apige-
nin 7-O-a-ʟ -rhamnopyranoside (1) and 3-hydroxyl-apigenin 8-C-
b-ᴅ-xylopyranoside (2), along with five known compounds (3-7),
were isolated from Xanthium strumarium. Their structures were
elucidated on the basis of spectroscopic and physicochemical analy-
ses. All compounds were evaluated for in vitro inhibitory activity
against PTP1B. Among them, compounds 1 and 5 showed signifi-
cant inhibitory activity on PTP1B with IC50 values of 11.3 1.7 and
8.9 0.7 lM, respectively.
KEYWORDS
Xanthium strumarium;
Compositae; flavonoid
glycosides; PTP1B
1. Introduction
Xanthium strumarium L. (Compositae) is an annual herb with irregularly toothed
leaves and small oblong fruits with covered curved hooks [1]. In China, X. struma-
rium is popularly known as “Cang-Er-Zi” and widely distributes in the northern
regions of China. And it was used for treating nasosinusitis, headache, pruritus, and
rheumatic arthralgia as a traditional Chinese medicine [2–4]. And the leaf decoction of
X. strumarium was used orally to treat malaria fever in North East India [5].
Phytochemical investigations have shown that X. strumarium contains several classes of
compounds such as flavonoid, ent-kauranoid glycoside, lignan, phenolic acid, and
CONTACT Xiang-Wei Xu
xiangweixuphd@163.com
Department of Pharmacy, The First People’s Hospital of
Yongkang, Yongkang 321300, China
Supplemental data for this article is available online at https://doi.org/10.1080/10286020.2021.1873957.
These authors contributed equally to this work.
ß 2021 Informa UK Limited, trading as Taylor & Francis Group
ꢀ

2
P.-J. JIANG ET AL.
Figure 1. The structures of compounds 1 and 2.
sesquiterpene lactone [6–8]. A variety of biological properties including anti-diabetes, anti-
inflammatory, diuretic, anthelmintic, antifungal, anti-cancer were also reported [9–14].
As a part of our ongoing program towards the discovery of new protein tyrosine
phosphatase 1B (PTP1B) inhibitors from natural sources, X. strumarium was investi-
gated. As a result, two new flavonoid glycosides (1–2), together with five known com-
pounds (3–7), were isolated from X. strumarium (Figure 1). And their structures
were elucidated on the basis of NMR analyses and mass spectrometry. Herein, we
report the isolation, structural elucidation, and PTP1B inhibitory activities of
these compounds.
2. Results and discussion
Compound 1 was obtained as a yellow amorphous powder, and the molecular for-
mula was determined to be C22H22O11 by HREIMS at m/z 462.1024 for the [M]þ.
The IR spectrum revealed the absorptions of hydroxy (3431 cmꢁ1), c-pyrone
(1662 cmꢁ1) and double bonds (1589 cmꢁ1). The 1H NMR spectrum (Table 1)
showed a set of aromatic protons at dH 7.76 (d, J ¼ 9.0 Hz, H-20,60) and 6.92 (d,
J ¼ 8.4 Hz, H-30,50), a penta-substituted aromatic ring at dH 6.21 (s, H-8), and a
methoxy group at dH 3.85. The 13C NMR spectrum of 1 indicated twenty-two car-
bons including twelve aromatic carbons, a chelated carbonyl carbon at dC 177.7 (C-
1
4), two olefinic carbons at dC 148.8 (C-2) and 134.2 (C-3). Combination of H NMR
and 13C NMR data of 1 established the basic skeleton of a known compound 6-
hydroxy-kaempferol [15]. In addition, the key HMBC correlations of dH 6.21 (H-8)
with dC 132.6 (C-6), 152.6 (C-7) and 150.0 (C-9), dH 12.63 (OH-5) with dC 145.5 (C-
5), 132.6 (C-6), 104.1 (C-10), and dH 3.85 with dC 134.2 (C-3) could further deter-
mine the structure of 6-hydroxy-3-methoxy-apigenin. The anomeric proton of the
sugar at dH 5.29 (d, J ¼ 1.2 Hz, H-10’) and a methyl group at dH 0.79 (d, J ¼ 6.0 Hz,
H-60’) suggested that it was a a-ʟ-rhamnopyranoside. The 13C NMR spectrum of 1
exhibited signals of six carbons at dC 101.8 (C-10’), 70.3 (C-20’), 70.6 (C-30’), 71.1 (C-
40’), 70.1 (C-50’), and 17.5 (C-60’), which were in good accordance with the presence
of a a-ʟ-rhamnopyranoside. And sugar moiety could also be further confirmed by
acid hydrolysis experiment. Furthermore, a long range correlation between the
anomeric proton at dH 5.29 (d, J ¼ 1.2 Hz, H-10’) and the carbon at dC 152.6 (C-7) of
the flavonoid skeleton in HMBC spectrum determined the position of a-ʟ

JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH
3
Table 1. 1H and 13C NMR spectral data of compounds 1 and 2 in DMSO-d6 (1H: 600 MHz,
13C: 125 MHz).
1
2
No
dH
dC
dH
dC
2
3
4
5
6
7
8
9
10
10
20
30
40
50
60
10’
20’
30’
40’
50’
148.8
134.2
177.7
145.5
132.6
152.6
93.7
150.0
104.1
120.5
130.6
115.4
159.6
115.4
130.6
101.8
70.3
148.6
135.7
182.1
161.1
98.4
163.0
104.6
155.9
103.9
121.1
129.5
116.0
160.5
116.0
129.5
74.6
6.25, s
6.21, s
7.76, d (9.0)
6.92, d (8.4)
8.21, d (9.0)
6.90, d (9.0)
6.92, d (8.4)
7.76, d (9.0)
5.29, d (1.2)
3.97, overlap
3.48, dd (9.6, 3.6)
3.16, overlap
3.30,
overlap
0.79, d (6.0)
3.85, s
6.90, d (9.0)
8.21, d (9.0)
4.62, d (8.4)
3.15-3.17, m
3.86-3.88, m
3.84-3.86, m
3.58-3.60, m
3.43-3.45, m
71.1
74.9
69.1
68.3
70.6
71.1
70.1
60’
-OCH3
5-OH
17.5
55.6
12.63, s
13.29 ,s
-rhamnopyranoside (Figure 2). Thus, the structure of 1 was determined as 6-
hydroxy-3-methoxy-apigenin 7-O-a-ʟ-rhamnopyranoside.
Compound 2, isolated as a yellow amorphous powder, gave a molecular formula
of C20H18O10 according to an [M]þ ion at m/z 418.0865 in its HREIMS. The kaemp-
ferol skeleton of this compound was supported by comparison of its NMR data with
those of 1 and kaempferol, which showed signals of protons and carbons for the
kaempferol and sugar moiety. However, the observation of anomeric proton at dH
1
4.62 (d, J ¼ 8.4 Hz, H-10’), according to the analysis of H, 13C NMR spectra, HMBC
data, the carbon signals of sugar [dC 74.6 (C-1), 71.1 (C-2), 74.9 (C-3), 69.1 (C-4),
68.3] suggested that the type of glycoside was b-ᴅ-xylopyranoside, which was com-
pletely consistent with results of the acid hydrolysis of 2. The key HMBC correlations
of dH 4.62 (H-10’) with dC 104.6 (C-8), and dH 6.25 (H-6) with dC 161.1 (C-5), 163.0
(C-7), 104.6 (C-8), and 103.9 (C-10) showed C-10’ of b-ᴅ-xylopyranoside was directly
linked with C-8. Thus, the structure of 2 was determined as 3-hydroxyl-apigenin 8-C-
b-ᴅ-xylopyranoside.
Along with two new flavonoid glycosides, five known compounds (3-7) were
obtained from X. strumarium. The known compounds were identified as 5,7,30,40-tet-
rahydroxyisoflavone (3) [16], formononetin 7-O-b-ᴅ-glucopyranoside (4) [17], kushe-
nol O (5) [18], 3-caffeoylquinic acid (6) [19], 6-hydroxykaempferol 3-glucoside (7)
[20] based on NMR data and comparison with literatures.
The isolated compounds 1-7 were evaluated for their inhibitory activities against
PTP1B, and RK-682 was used to be the positive control (Table 2). The data suggested
that all isolates except compounds 6 and 7 had different level of inhibitory activities

4
P.-J. JIANG ET AL.
Figure 2. Key HMBC correlations of compounds 1 and 2.
Table 2. PTP1B inhibitory activity of compounds 1-7 (lM).
a
Compounds
IC50
1
2
3
4
5
6
11.3 1.7
18.3 0.8
31.2 1.1
23.1 1.3
8.9 0.7
>60
7
>60
4.2 0.5
RK-682b
a
IC50 values were determined by regression analyses and expressed as means SD of three replicates.
Positive control.
b
on PTP1B. And compounds 1 and 5 showed significant inhibitory activity on PTP1B
with IC50 values of 11.3 1.7 and 8.9 0.7 lM, respectively. Although compound 7
didn’t show inhibitory activity on PTP1B, this result still revealed that some flavonoid
glycosides might have potential effect on PTP1B inhibition. Thus, further investiga-
tion and optimization of the derivatives of flavonoid glycoside inhibiting PTP1B
might need to be intensified.
3. Experimental
3.1. General experimental procedures
Optical rotations were determined on a Perkin-Elmer 241MC automatic digital polar-
imeter (PerkinElmer, Waltham, USA). UV spectra were recorded on Shimadzu UV-
2401PC spectrophotometer (Shimadzu Corporation, Tokyo, Japan). IR spectra were
recorded with a Bruker IFS-55 IR spectrometer with KBr disks (Bruker, Karlsruhe,
German). Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker
Avance III 600 MHz spectrometer with tetramethylsilane (TMS) as an internal stand-
ard (Bruker, Karlsruhe, Germany). Mass spectra were obtained on a Bruker APEX II
mass spectrometer, and EIMS were recorded using an HP-5988 MS spectrometer
(Bruker, Karlsruhe, Germany). Column chromatography was conducted using silica
gel (200-300 lm particle size, Qingdao Marine Chemical Factory, Qingdao, China).
TLC was performed with precoated silica gel GF254 glass plates (Qingdao Marine
Chemical Factory, Qingdao, China). Preparative RP-HPLC was conducted on a
Shimadzu LC-6AD instrument and a SPD-20A detector (Shimadzu, Kyoto, Japan)

JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH
5
using a YMC-Pack ODS-A column (10 ꢂ 250 mm, 5 lm particle size, Shiseido Fine
Chemicals, Tokyo, Japan).
3.2. Plant material
Xanthium strumarium were collected in Hezi, Shandong province, China, and
authenticated by Professor Hongchang Gao (College of Pharmacy, Wenzhou Medical
University). A voucher specimen of the plant (No. 20190814) was deposited at the
College of Pharmacy, Wenzhou Medical University, Wenzhou, China.
3.3. Extraction and isolation
The dried X. strumarium (15.0 kg) was extracted with 75% EtOH to give an extract
(1.4 kg). This extract was suspended in water and partitioned by petroleum ether
(PE), EtOAc and n-BuOH, respectively. The EtOAc fraction (312.5 g) was separated
into eighteen fractions (Fr.1-Fr.18) using Si gel column chromatography (CC) with a
gradient of CH2Cl2-MeOH (from 100:1 to 0:1). Fr.9 (25.6 g) was divided into twelve
parts (Fr.9.1-Fr.9.12) by a Si gel CC eluting with gradient PE-EtOAc (from 50:1 to
0:1). Furthermore, Fr.9.7 (2.9 g) was subjected to the RP-18 column using the elution
of MeOH-H2O (from 20:80 to 100:0) to afford eleven fractions (Fr.9.7.1-Fr.9.7.11).
Fr.9.7.5 (689.3 mg) was applied to C18 reversed-phase HPLC column and eluted with
a gradient of 45%-65% MeOH in H2O at a flow rate of 3.0 ml/min over 120 min.
This resulted in the isolation of compound 1 (6.7 mg, tR ¼ 39.2 min), compound 2
(9.3 mg, tR ¼ 49.8 min), compound 5 (10.8 mg, tR ¼ 55.3 min), compound 3 (5.8 mg,
tR ¼ 59.5 min), compound 4 (7.4 mg, tR ¼ 68.5 min) and compound 6 (6.8 mg, tR
¼ 77.5 min).
3.3.1. 6-Hydroxy-3-methoxy-apigenin 7-O-a-ʟ-rhamnopyranoside (1)
25
Yellow amorphous powder; ½aꢃD ꢁ37.5 (c 0.1, MeOH); UV (MeOH) kmax (log e): 262
(4.00), 273 (3.70), 294 (2.18), 300 (2.15), 321 (2.38), 350 (2.30) nm; IR (KBr disc)
1
ꢀmax 3431, 2947, 1662, 1589, 1550, 1509, 1389 cmꢁ1; H (600 MHz) and 13C NMR
(150 MHz) spectral data in DMSO-d6, see Table 1; HREIMS: m/z 462.1024 [M]þ
(calcd for C22H22O11, 462.1162).
3.3.2. 3-Hydroxyl-apigenin 8-C-b-ᴅ-xylopyranoside (2)
25
Yellow amorphous powder; ½aꢃD ꢁ46.3 (c 0.1, MeOH); UV (MeOH) kmax (log e): 272
(1.57), 299 (1.24), 369 (1.22) nm; IR (KBr disc) ꢀmax 3442, 2921, 1653, 1597, 1554,
1
1502, 1380cmꢁ1; H (600 MHz) and 13C NMR (150 MHz) spectral data in DMSO-d6,
see Table 1; HREIMS: m/z 418.0865 [M]þ (calcd for C20H18O10, 418.0900).
3.4. PTP1B assay
The enzyme activity was measured according to previous method [21]. Briefly, each
96 well (final volume: 100 ll) was added 2 mM p-nitrophenyl phosphate (pNPP) and
PTP1B (0.05-0.1 lg) in a buffer containing 50 mM citrate (pH 6.0), 0.1 M NaCl,

6
P.-J. JIANG ET AL.
1 mM ethylene diamine tetraacetic acid (EDTA), and 1 mM dithiothreitol (DTT),
with or without test compounds. Following incubation at 37 ꢄC for 30 min, the reac-
tion was terminated with 1 M NaOH. The amount of produced p-nitrophenol was
estimated by measuring the absorbance at 405 nm.
3.5. Acid hydrolysis of compounds 1 and 2
An aqueous solution (3 ml) of each sample (2 mg) was refluxed with 2 M HCl (3 ml)
at 100 ꢄC for 4 h. After neutralization with NaHCO3 solution, the reaction mixture
was extracted with EtOAc (2 ꢂ 10 ml). The collected organic phase was evaporated
and subjected to PTLC using CHCl2-MeOH (5:1) as eluent to yield the aglycone. The
water layer was concentrated and submitted to PTLC (CHCl2/MeOH/H2O ¼ 7:3:0.5)
to yield the sugars which were identified by TLC (CHCl2/MeOH/H2O ¼ 7:3:0.5)
20
20
with authentic samples and ½aꢃD as follows: ᴅ-xylose (½aꢃD þ19.2) and ʟ-rhamnose
20
(½aꢃD þ8.0) [22].
Acknowledgements
The authors wish to express thanks to the First People’s Hospital of Yongkang for providing a
research grant and the Department of Instrumental Analysis of Wenzhou Medical University
for the measurement of the UV, IR, HREIMS and NMR.
Disclosure statement
No potential conflict of interest was reported by the authors.
References
[1] R.K. Sahoo, K.J. Tamuli, N. Lhouvum, D. Dutta, M. Bordoloi, H.K. Sharma, K. Gogoi,
and D.R. Bhattacharyya, S. Afr. J. Bot. 135, 35 (2020).
[2] H. Jiang, G.X. Ma, L. Yang, X.D. Xing, M.L. Yan, Y.Y. Zhang, Q.H. Wang, H.X.
Kuang, and X.D. Xu, Phytochem. Lett. 18, 192 (2016).
[3] T. Han, H.L. Li, Q.Y. Zhang, H.C. Zheng, and L.P. Qin, Chem. Nat. Compd. 42, 567
(2006).
[4] R.H. Yin, X. Bai, T. Feng, Z.J. Dong, Z.H. Li, and J.K. Liu, J. Asian Nat. Prod. Res. 18,
354 (2016).
[5] R. Shankar, S. Deb, and B.K. Sharma, J. Ayurveda Integr. Med. 3, 10 (2012).
[6] S.M. Mangel, K.S. Naresh, and S.D. Kuldip, Phytochemistry 32, 206 (1992).
[7] L. Qin, T. Han, H. Li, Q.Y. Zhang, and H.C. Zheng, Fitoterapia 77, 245 (2006).
[8] Y.H. Dai, Z. Cui, and J.L. Li, J. Shenyang Pharm. Univ. 24, 786 (2007).
[9] H. Huang, J.G. Yu, and L. Sun, China J. Chin. Mater. Med. 30, 1027 (2005).
[10] S.H. Hwang, Z. Wang, H.N. Yoon, and S.S. Lim, Molecules 21, 1241 (2016).
[11] W.X. Fan, L.H. Fan, C.Y. Peng, Q. Zhang, L. Wang, L. Lin, J.L. Wang, D.Y. Zhang, W.
Peng, and C.J. Wu, Molecules 24, 359 (2019).
[12] B. Lin, Y. Zhao, P. Han, W. Yue, X.Q. Ma, K. Rahman, C.J. Zheng, L.P. Qin, and T.
Han, J. Ethnopharmacol. 155, 248 (2014).
[13] S.R. Sharma, D. Singh, F.A. Khan, C.P. Swarankar, and P.S.K. Bhagwan, Indian. J.
Anim. Sci. 73, 342 (2003).

JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH
7
[14] M. Lavault, A. Landreau, G. Larcher, J.P. Bouchara, F. Pagniez, P.L. Pape, and P.
Richomme, Fitoterapia 76, 363 (2005).
[15] L.E. Urbatsch, J.D. Bacon, and T.J. Mabry, Phytochemistry 14, 2279 (1975).
[16] N.T. Hiep, J. Kwon, D.W. Kim, S. Hong, Y. Guo, B.Y. Hwang, N. Kim, W. Mar, and
D. Lee, Tetrahedron 73, 2747 (2017).
[17] M.S. Kim, J.S. Park, Y.C. Chung, S.C. Jang, C.G. Hyun, and S.Y. Kim, Molecules 24,
3910 (2019).
[18] C. Zhang, Y.M. Wang, F.C. Zhao, L.M. Chen, Q.W. Zhang, H.M. Gao, and Z.M. Wang,
Helv. Chim. Acta 94, 1516 (2014).
[19] P.R. Lin, P.C. Kuo, Y.C. Lia, C.F. Jhuo, W.L. Hsu, and J.T.C. Tzena, J. Ethnopharmacol.
262, 1 (2020).
[20] M. Hattori, X.L. Huang, Q.M. Ch, Y. Kawat, Y. Tezuk, T. Kikuchi, and T. Namba,
Phytochemistry 31, 4001 (1992).
[21] N. Li, Z.D. Tuo, S.S. Xing, S.Z. Qi, H.S. Lee, and L. Cui, Bull. Korean Chem. Soc. 35,
3122 (2014).
[22] T.Y. Xu, Z.H. Wang, T.L. Lei, C.N. Lv, J. Wang, and J.C. Lu, Fitoterapia 101, 125
(2015).