A new phenol glycoside from Physalis angulata

Article abstract of DOI:10.1080/14786419.2016.1269102

A new phenol glycoside, physanguloside A (1), was isolated from Physalis angulata together with four known compounds. We report herein, for the first time, the presence of compounds 2–5 in the genus Physalis. The structures of all the compounds were established by NMR, IR, UV and HRESIMS spectroscopic analyses, and comparison with the literature data. All isolated compounds were assayed for inhibitory activity on nitric oxide production by LPS-induced in RAW 264.7 macrophages.

Full text of DOI:10.1080/14786419.2016.1269102

Natural Product Research
Formerly Natural Product Letters
ISSN: 1478-6419 (Print) 1478-6427 (Online) Journal homepage: http://www.tandfonline.com/loi/gnpl20
A new phenol glycoside from Physalis angulata
Cheng-Peng Sun, Xiu-Fang Nie, Ning Kang, Feng Zhao, Li-Xia Chen & Feng Qiu
To cite this article: Cheng-Peng Sun, Xiu-Fang Nie, Ning Kang, Feng Zhao, Li-Xia Chen & Feng
Qiu (2016): A new phenol glycoside from Physalis angulata, Natural Product Research, DOI:
10.1080/14786419.2016.1269102
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Date: 03 January 2017, At: 03:54

Natural Product research, 2016
http://dx.doi.org/10.1080/14786419.2016.1269102
A new phenol glycoside from Physalis angulata
Cheng-Peng Suna,b, Xiu-Fang Nieb, Ning Kanga, Feng Zhaoc, Li-Xia Chenb and
Feng Qiua,b
atianjin state Key laboratory of Modern chinese Medicine and school of chinese Materia Medica, tianjin
b
university of traditional chinese Medicine, tianjin, china; Key laboratory of structure-Based drug design
& discovery, Ministry of education, department of Natural Products chemistry, school of traditional chinese
c
Materia Medica, shenyang Pharmaceutical university, shenyang, china; Key laboratory of Molecular
Pharmacology and drug evaluation, Ministry of education, collaborative Innovation center of advanced drug
delivery system and Biotech drugs in universities of shandong, school of Pharmacy, Yantai university, Yantai,
china
ABSTRACT
ARTICLE HISTORY
received 14 July 2016
accepted 20 November 2016
A new phenol glycoside, physanguloside A (1), was isolated from
Physalis angulata together with four known compounds. We report
herein, for the first time, the presence of compounds 2–5 in the genus
Physalis. The structures of all the compounds were established by
NMR, IR, UV and HRESIMS spectroscopic analyses, and comparison
with the literature data. All isolated compounds were assayed for
inhibitory activity on nitric oxide production by LPS-induced in RAW
264.7 macrophages.
KEYWORDS
Physalis angulata; phenol
glycoside; nitric oxide
1. Introduction
Physalis angulata L. (known in Chinese as ‘ku-zhi’) is a member of the genus Physalis
(Solanaceae) comprising approximately 120 species widely distributed in tropical and sub-
tropical regions (Institute of Botany of the Chinese Academy of Sciences & Kunming Institute
of Botany of the Chinese Academy of Sciences 1978). As a traditional folk medicine, P. angu-
lata has been used to cure inflammatory-related diseases, such as dermatitis, asthma, hep-
atitis and malaria in other countries such as Peru, Mexico and Brazil (Di Stasi et al. 1989).
Phytochemical investigations of the genus Physalis have led to the isolation of withanolides
(Chen et al. 2007; Qiu et al. 2008a; Guan et al. 2014; Nicolás et al. 2015), labdane-type
CONTACT li-Xia chen
syzyclx@163.com; Feng Qiu
fengqiu20070118@163.com
supplemental data for this article can be accessed at http://dx.doi.org/10.1080/14786419.2016.1269102.
© 2016 Informa uK limited, trading as taylor & Francis Group

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C.-P. SUN ET AL.
Figure 1. chemical constituents of P. angulata.
diterpenes (Pérez-Castorena et al. 2006, 2010; Maldonado et al. 2015), flavonoids (Qiu et al.
2008a; Maldonado et al. 2012), megastigmane glycosides (Qiu et al. 2008b), alkaloids (Basey
et al. 1992; Asano et al. 1995), ceramides (Su et al. 2002) and acylsucroses (Maldonado et al.
2006). Some of the isolated compounds have shown significant pharmacological activities,
including anti-inflammatory (Choi & Hwang 2003; Bastos et al. 2008; He et al. 2014), antitumor
(Hsieh et al. 2006; Hseu et al. 2011; He, Zang, Feng, Wang, 2013; He, Zang, Feng, Chen, 2013;
Zhang et al. 2014), immunomodulatory (Kusumaningtyas et al. 2015) and antinociceptive
(Bastos et al. 2006) activities.
As part of our ongoing search to obtain potential anti-inflammatory agents from P. angu-
lata (Sun et al. 2016a, 2016b), 75% EtOH extract of P. angulata was subjected to various
chromatographic techniques to afford a new phenol glycoside, physanguloside A (1) and
four known compounds including a phenylcarbinol glycoside (2), two phenol glycosides (3
and 5) and a phenethanol glycoside (4) (Figure 1). Their structural elucidations were identified
by NMR, IR, UV and HRESIMS analysis. All isolated compounds were evaluated for inhibitory
effects on nitric oxide production in RAW 264.7 macrophages.
2. Results and discussion
Physanguloside A (1) was obtained as a pale yellow amorphous powder. Its molecular for-
mula was deduced as C20H28O13 by the positive HRESIMS m/z 499.1434 [M + Na]+ and 13C
NMR data, indicating 7 degrees of unsaturation. The IR spectrum of 1 showed absorption
1
bands of hydroxy (3424 cm−1) and aromatic (1646 and 1468 cm−1) functionalities. The H
NMR data of 1 (Table S1) showed signals of a methoxy group at δH 3.88 (3H, s) and four
aromatic protons at δH 7.69 (1H, dd, J = 7.9, 1.8 Hz, H-6), 7.52 (1H, td, J = 7.9, 1.8 Hz, H-4), 7.25
(1H, br d, J = 7.9 Hz, H-3) and 7.07 (1H, br t, J = 7.9 Hz, H-5), suggesting the presence of
12-disubstituted benzene. In addition, two anomeric signals at δH 5.34 (1H, d, J = 7.4 Hz,
H-1′) and 4.82 (1H, d, J = 7.7 Hz, H-1′′) indicated the presence of two glycoses. The 13C NMR
spectrum of 1 revealed 20 carbon resonances, including a carboxyl carbon (δC 168.1), 6
aromatic carbons (δC 157.7, 135.0, 132.5, 122.6, 121.5 and 116.4), 2 anomeric carbons
(δC 104.5 and 99.8), 10 oxygenated carbons (δC 83.1, 77.9, 77.8, 77.7, 77.5, 76.2, 71.0, 70.9,

NATURAL PRODUCT RESEARCH
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62.5 and 61.6) and a methoxy carbon (δC 52.8). The above NMR data indicated that 1 was a
phenol glycoside.
HPLC with an optical rotation detector (HPLC-OR) is widely used to determine enantiomers
(Yamamoto et al. 2008), and can also be performed for the configuration of glycoses (Sun
et al. 2016b; Wang et al. 2016). Two glycoses were identified by HPLC-OR analysis for hydro-
lysed products of 1 to be D-glucose. The anomeric configurations of two glucoses were
deduced as a β-orientation based on the coupling constants [δH 5.34 (1H, d, J = 7.4 Hz, H-1′)
and 4.82 (1H, d, J = 7.7 Hz, H-1′′)] (Sun et al. 2016b). In the HMBC spectrum of 1, long-range
correlations of H-1′ with C-2, H-1′′ with C-2′, H-6 with C-7, and OCH3 with C-7 (Figure S1)
indicated the locations of two glucoses, the methoxy group and the ester carbonyl group.
The NOESY cross-peaks of H-3 with H-1′/H-4, H-4 with H-5, and H-5 with H-6 (Figure S1)
further confirmed the above conclusion. Taking all above data into consideration, the struc-
ture of physanguloside A (1) was defined as methyl 2-(2′-O-β-D-glucopyranosyl)-β-D-
glucopyranosyloxybenzoate.
In addition, the investigation of the 75% EtOH extract of P. angulata led to the isolation
of four known compounds, including benzylalchohol O-α-L-arabinopyranosyl(1→6)-β-D-
glucopyranoside (2) (Kawahara et al. 2005), gaultherin (3) (Wang et al. 2011), phenetha-
nol-β-vicianoside (4) (Wang et al. 2012) and guaiacyl-β-D-primeveroside (5) (Mayr et al. 2014).
To the best of our knowledge, this is the first report of compounds 2–5 in the genus Physalis.
Nitric oxide (NO) is a well-known cellular signalling molecule and is considered as an
important regulator in many physiological mechanisms (Turtay et al. 2015; Bahnson et al.
2016; Ren et al. 2016). Pharmacological studies have indicated that inflammation is related
to overproduction of NO (Mulligan et al. 1991). P. angulata is a traditional folk medicine used
to treat inflammatory-related conditions, such as dermatitis, asthma, hepatitis and malaria.
In our previous studies, some compounds isolated from P. angulata, such as physangulatins
I, J and K, physagulides I and K and physagulin I, displayed a potent inhibition of NO pro-
duction (Sun et al. 2016a, 2016b). Therefore, all isolated compounds (1–5) were evaluated
for inhibitory effects on NO production induced by LPS in RAW 264.7 macrophages (Table
S2). However, none of the isolates displayed significant inhibitory effect against NO
production.
3. Experimental
3.1. General experimental procedures
Optical rotations were recorded on a Perkin-Elmer 241 polarimeter (Perkin-Elmer, Waltham,
MA, USA). UV spectra were measured with a Shimadzu UV 2201 spectrophotometer
(Shimadzu Corporation, Kyoto, Japan). IR spectra were carried out on a Bruker IFS 55 spec-
trometer (Bruker Optics, Ettlingen, Germany). NMR experiments were performed on Bruker
AV-400 and AV-600 spectrometers (Bruker Biospin, Fallanden, Switzerland). Chemical shift
values are expressed in δ (ppm) using the peak signals of the solvent MeOH-d4 (δH 3.31 and
δC 49.2) as the reference. HRESIMS were obtained on an Agilent 6210 TOF mass spectrometer
(Palo Alto, USA). AB-8 resins were purchased from the Chemical Plant of NanKai University
(Tianjin, China). Silica gel GF254 used to prepare TLC plates and silica gel (200−300 mesh)
for column chromatography (CC) were obtained from Qingdao Marine Chemical Factory
(Qingdao, China). Sephadex LH-20 was a product of Pharmacia (Amersharm, Sweden).

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C.-P. SUN ET AL.
Octadecyl silica gel was purchased from Merck Chemical Company Ltd (Darmstadt, German).
RP-HPLC equipped with an LC-6AD liquid chromatograph, SPD-20A UV detector (Shimadzu,
Kyoto, Japan) and ODS column (250 × 20 mm, 5 μm, 120 Å, YMC Co. Ltd) was used for the
separation. All reagents were purchased from Tianjin Damao Chemical Company (Tianjin,
China). Spots were detected on TLC plates under UV light or heated after spraying with
anisaldehyde-H2SO4 reagent.
3.2. Plant material
The stems and leaves of P. angulata were collected in Nanning, Guangxi Province, China, in
July 2013. It was identified by Jia-Fu Wei, Guangxi Institute for Food and Drug Control, and
a voucher specimen (PA-20130826) has been deposited in the herbarium of the Department
of Natural Products Chemistry, Shenyang Pharmaceutical University.
3.3. Extraction and isolation
The dried stems and leaves of P. angulata (9.5 kg) were extracted with 75% EtOH (110
L × 2 h × 2). The extract (1.3 kg) was concentrated in vacuo, suspended with H2O (5 L), and
partitioned with petroleum ether (5 L × 3), EtOAc (5 L × 3) and n-BuOH (5 L × 3), successively.
The n-BuOH extract (102.0 g) was subjected to AB-8 resin CC (10 × 80 cm) eluted with EtOH/
H2O (0:100, 30:70, 60:40 and 95:5) to obtain four fractions (B1−B4). Fraction B2 (10.0 g) was
separated by ODS CC (3 × 50 cm), MeOH−H2O as eluent (1:9 to 1:0), yielding three subfrac-
tions (B21−B23). Subfraction B23 (2.0 g) was purified by a Sephadex LH-20 column (3 × 80 cm)
using MeOH as eluent to afford three subfractions (B231-B233). Finally, compounds 1 (15 mg,
tR = 20 min), 2 (38 mg, tR = 15 min), 3 (21 mg, tR = 16 min), 4 (5 mg, tR = 34 min) and 5 (3 mg,
tR = 24 min) were obtained from subfraction B232 (870 mg) by preparative a HPLC analysis
(CH3CN-H2O, 20:80).
Physanguloside A (1): pale yellow amorphous powder; [ꢀ]2D5 − 29.3 (c 0.075, MeOH); UV
(MeOH) λmax (log ε) 222 (3.9), 289 (3.9) nm; IR (KBr) νmax 3396, 2921, 2850, 1717, 1646, 1468,
1384, 1122 cm−1; 1H (400 MHz, MeOH-d4) and 13C NMR (100 MHz, MeOH-d4) data, see Table
S1; HRESIMS m/z 499.1434 [M + Na]+ (calcd for C20H28O13Na, 499.1428).
3.4. Acid hydrolysis of compound 1
Compound 1 (4 mg) was dissolved in 2 M HCl (3.0 mL) and stirred at 90 °C for 3 h (Sun et al.
2016b; Wang et al. 2016). The reaction mixture was extracted with CHCl3, and the aqueous
layer was evaporated to give a monosaccharide. The residue was analysed by HPLC using a
Jasco LC-NetII/ADC system, equipped with a Jasco OR-4090 detector, a gradient pump, and
a Shodex Asahipak NH2P-50 4E column (250 × 4.6 mm, 5 μm). A 20 μL sample was injected,
and the mobile phase was a solvent of CH3CN-H2O (75:25). The HPLC spectrum of D-glucose
(No. 492–61-5, ChromaDex Inc., USA) showed the positive peak at 12.5 min, and that of
L-glucose (No. 921–60-8, Tokyo Chemical Industry Co., LTD, Japan) showed the negative peak
at 12.5 min.

NATURAL PRODUCT RESEARCH
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3.5. NO Production Bioassay
All compounds were assayed for the inhibition of NO production according to Griess method
(Li et al. 2010; Sun et al. 2016a). 1 × 106 Cells/well of RAW 264.7 cells were placed into 96-well
plates, and incubated at 37 °C for 24 h by the stimulation of LPS (1 μg/mL) with or without
test compounds. After the addition of Griess reagent [0.1% N-(1-naphthyl)ethylenediamine
(50 μL); 1% sulphanilamide in 5% H3PO4 (50 μL)], absorbance (540 nm) was recorded using
a microplate reader. The standard curve was used to calculate the NO concentrations and
inhibitory rates.
4. Conclusion
In summary, a new phenol glycoside (1) and four known compounds (2–5) were isolated
from the stems and leaves of P. angulata. This is the first report about the presence of phenol
glycoside derivatives (2–5) in the genus Physalis. Furthermore, compounds 1–5 were eval-
uated for their effects on NO production in RAW 264.7 macrophages.
Supplementary material
Supplementary material relating to this article is available online, alongside with Figures S1–S10.
Disclosure statement
No potential conflict of interest was reported by the authors.
Funding
This work was financially supported by grants from the National Natural Science Foundation of China
(NSFC) [grant number 81430095]; Fund of the Educational Department of Liaoning Province [grant
number L2011177]; Liaoning Baiqianwan Talents Program [grant number 2013921043]; 2015 Career
Development Program for Young and Middle-aged Teachers of Shenyang Pharmaceutical University
[grant number ZQN2015015].
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