Gum arabic-OPO3H2as a new natural-based green catalyst for the one-pot pseudo-four-component synthesis of naphtho[1,2-: E] [1,3]oxazines

Article abstract of DOI:10.1039/d0ra07199d

Gum arabic-OPO3H2 (GA-OPO3H2) as a unique natural-based green catalyst was synthesized by the reaction of phosphorus pentoxide with gum arabic. The structure and properties of the catalyst were studied via several analysis methods such as FT-IR, MAPPING, EDS, SEM, XRD, and TGA. The efficiency of the above-mentioned catalyst was investigated for the synthesis of naphtho-1,3-oxazines via a pseudo-four-component reaction of primary amines, formaldehyde, and 2-naphthol under the solvent-free grinding condition at room temperature using an electrical mortar-heater. The obtained results indicated that GA-OPO3H2 is a highly efficient green catalyst for the synthesis of naphtho[1,2-e][1,3]oxazines with high yields, simple workup, and benign reaction condition.

Full text of DOI:10.1039/d0ra07199d

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Gum arabic-OPO H as a new natural-based green
3
2
catalyst for the one-pot pseudo-four-component
Cite this: RSC Adv., 2020, 10, 40508
synthesis of naphtho[1,2-e][1,3]oxazines†
Sahar Saadat Hosseinikhah, Bi Bi Fatemeh Mirjalili, *a Naeimeh Salehia
a
b
and Abdolahamid Bamoniri
3 2 3 2
Gum arabic-OPO H (GA-OPO H ) as a unique natural-based green catalyst was synthesized by the
reaction of phosphorus pentoxide with gum arabic. The structure and properties of the catalyst were
studied via several analysis methods such as FT-IR, MAPPING, EDS, SEM, XRD, and TGA. The efficiency of
the above-mentioned catalyst was investigated for the synthesis of naphtho-1,3-oxazines via a pseudo-
four-component reaction of primary amines, formaldehyde, and 2-naphthol under the solvent-free
grinding condition at room temperature using an electrical mortar-heater. The obtained results indicated
Received 21st August 2020
Accepted 13th October 2020
DOI: 10.1039/d0ra07199d
3 2
that GA-OPO H is a highly efficient green catalyst for the synthesis of naphtho[1,2-e][1,3]oxazines with
rsc.li/rsc-advances
high yields, simple workup, and benign reaction condition.
a primary amine, (2) aza-acetalization of aromatic aldehydes
with 2-(N-substituted aminomethyl) phenols in the presence of
Introduction
For the synthesis of organic compounds, the need for envi- an acid as a catalyst and (3) electrooxidative cyclization of
21
ronmentally friendly conditions, green pathways, and low-cost hydroxyamino compounds. The most common method for the
with short reaction times is increasing. Therefore, it is pref- synthesis of naphtho[1,2-e][1,3]oxazines is the multicomponent
erable to use the natural-based catalysts and solvent-free reaction of 2-naphthol, formaldehyde and a primary amine via
methods. Gum Arabic (GA) is a biodegradable and renewable a Mannich-type condensation. The synthesis of naphtho[1,2-e]
glucoprotein, which is an exudate collected from the stems [1,3]oxazines using MCRs offers signicant advantages
1
,2
and branches of Acacia trees. GA is also known to be including a reduction in the number of steps, energy
a branched and complex acidic heteropolysaccharide whose consumption, and waste production.
main chain consists of (1/3)-b-D-galactopyranosyl units and
Some of the catalysts that have previously been used for the
22
4 2 2
side chains consists of L-arabinofuranosyl, L-rhamnopyr- synthesis of these products are KAl(SO ) $12H O (alum),
2
3
anosyl, D-galactopyranosyl, and D-glucopyranosyluronic acid ZrOCl
,
1-benzyl- 3-methyl imidazolium hydrogen sulfate
2
3
,4
24
25
units. GA is generally safe, and in recent years, it has been [bnmim] [HSO
], polyethylene glycol (PEG), and thiamine
4
5
–9
10,11
26
widely used as a support, hydrogel
and gold nanoparticle hydrochloride (VB ). Despite the remarkable achievements for
1
1
2
stabilizer. 1,3-Oxazines as an important class of heterocycles the synthesis of naphtho[1,2-e][1,3]oxazine derivatives, some of
have wide biological and pharmacological activities such as these catalysts have limitations such as inefficient separation of
antitumor, antibacterial, anti-HIV, analgesic, antihy- the catalyst from reaction mixtures, unrecyclable and environ-
1
3
14
15
16
1
7
18
19
pertensive,
antithrombotic,
and antiulcer activities.
mental limitations. Furthermore, this reaction was performed
27,28
Moreover, naphthoxazine derivatives have exhibited thera- without a catalyst under harsh reaction conditions.
2
0
peutic potential for the treatment of Parkinson's disease.
Based on the biological importance of benzo-fused 1,3-oxa- procedure for the synthesis of naphtho[1,2-e][1,3]oxazines
zines, numerous methods have been developed for the using GA-OPO as a new natural-based green catalyst via the
In this study, we wish to report an efficient eco-friendly
H
2
3
synthesis of pseudo-four-component including (1) Mannich- reaction of primary amines, formaldehyde, and 2-naphthol.
type condensation of 1- or 2-naphthol, formaldehyde, and
Results and discussion
a
Department of Chemistry, College of Science, Yazd University, P. O. Box 89195-741,
In this study, an efficient and environmentally benign protocol
was developed for the synthesis of naphtho[1,2-e][1,3]oxazine
derivatives using a pseudo-four-component reaction of primary
Yazd, Iran. E-mail: fmirjalili@yazd.ac.ir; Fax: +983538210644; Tel: +983531232672
b
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan,
Kashan, Iran
amines, formaldehyde, and 2-naphthol in the presence of GA-
OPO . The steps for the synthesis of the GA-OPO catalyst
†
Electronic supplementary information (ESI) available. See DOI:
0.1039/d0ra07199d
1
3
H
2
3 2
H
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are shown in Scheme 1. The as-synthesized catalyst was char-
acterized via FT-IR, XRD, SEM, MAPPING, EDS, and TGA.
The FT-IR (KBR) spectra of GA and GA-OPO H are shown in
3
2
Fig. 1. The characteristic absorption bands of GA at 1069 and
ꢀ
1
ꢀ1
1
148 cm (C–O, stretch), 1423 (O–H, bending), 1616 cm (C]
ꢀ
1
O, aliphatic acid), 2928 cm
(C–H, stretch), and 3000–
ꢀ
1
3
600 cm (O–H, stretch) can be observed (Fig. 1a). The strong
ꢀ1
peaks in the range of 900–1200 cm are the ngerprints of
carbohydrates. These peaks are observed in the case of GA and
ꢀ1
ꢀ1
GA-OPO H . The bands at 1071 cm (P–O–C) and 1228 cm
3
2
(P]O) are attributed to the stretching vibrations of the phos-
phoric acid section that overlaps with the absorption bands of
GA in this region.
3 2
Fig. 1 FT-IR spectra of (a) GA (b) GA-OPO H .
The particles size and morphology of GA-OPO
3 2
H were
investigated via SEM. The exterior surface of GA-OPO
3
H
2
appears as an irregular rocky surface in which the dimensions
were found to be below 10 mm (Fig. 2). Fig. 3 illustrates the
powder X-ray diffractograms obtained for natural GA, GA-
OPO H , and reused GA-OPO H , respectively. The broad peak
3
2
3
2
ꢁ
at 2q ¼ 19.895 (Fig. 3a) relates to the amorphous nature of GA.
Aer the reaction of P with GA, the intensity of the corre-
sponding peak decreases (Fig. 3b), verifying that P is bonded
to GA. Other peaks in the GA-OPO spectrum may be due to
2 5
O
2 5
O
3
H
2
the release of metals by the hydrolysis of calcium, magnesium,
and potassium salts of GA, their binding to free hydroxyl
groups, and the formation of metal complexes.
3 2
Fig. 2 SEM image of GA-OPO H .
Also, the presence of C, O, N, and P in the catalyst was
investigated via EDX analysis data (Fig. 4). The percentages of O,
C, N, and P in the catalyst are 57.53, 27.65, 8.33, and 6.49, gravimetric analysis (TGA) in the temperature range of
ꢁ
respectively. Fig. 5 shows the elemental mapping of GA- 33–404 C (Fig. 6). The TGA curve of gum arabic shows three
ꢁ
ꢁ
OPO
3
H
2
. The images and patterns recorded conrm the pres- steps of weight loss: (a) 10% at 70–150 C, (b) 50% at 250–320 C
ꢁ
ence of carbon, nitrogen, oxygen, and phosphorus elements in and (c) 10% at 320–400 C. The char yield of gum arabic at
the catalyst. In addition, it shows that catalyst functional groups 400 C is 30%. Also, the TGA curve of GA-OPO
are well-scattered throughout the catalyst. The thermal stability steps weight loss which contains (a) 5 % at 30–120 C, (b) 10% at
of gum arabic and GA-OPO H were evaluated via thermo- 150–220 C and (c) 15% at 250–400 C. The rst weight loss is
ꢁ
H
shows three
3
2
ꢁ
ꢁ
ꢁ
3
2
3
Scheme 1 Preparation of GA-OPO H.
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Fig. 6 Thermal gravimetric analysis pattern of (a) gum arabic, (b) GA-
3 2
OPO H .
3 2
Fig. 3 XRD patterns of the (a) GA, (b) GA-OPO H and (c) reused GA-
3 2
OPO H .
ꢁ
OPO
3
H
2
at 400 C is 63.96%. These evidences show that thermal
is higher than that of gum arabic. The
acidic capacity of the catalyst was measured via titrating it with
.03 N of NaOH. The number of OPO H groups on the gum GA-
3 2
stability of GA-OPO H
0
3
2
ꢀ
1
OPO H is 6.6 mmol g . The catalytic performance of GA-
3
2
OPO H was investigated in a one-pot reaction of 2-naphthol
3
2
(1 mmol), formalin (2 mmol), and primary amine (1 mmol)
towards the synthesis of naphtho[1,2-e][1,3]oxazines. Initially,
the optimization experiments were performed in the reaction of
2-naphthol (1 mmol), formalin (2 mmol), aniline (1 mmol)) as
the model reaction. The reaction was optimized via various
parameters such as temperature, solvent, and catalyst amounts,
and the results are summarized in Table 1. To investigate the
effect of reaction temperature, the reaction was performed at
different temperatures under solvent-free conditions (Table 1,
entries 8–11).
3 2
Fig. 4 EDS spectra of GA-OPO H .
The highest yield was achieved at room temperature using
an electrical mortar-heater (Table 1, entry 8). Different solvents
including H O, EtOH, CHCl , CH CN, H O : EtOH, MeOH were
2 3 3 2
attributed to the evaporation of free water and the second and
third weight loss steps corresponded to decomposition and
burning of the GA section of the catalyst. The char yield of GA-
also screened (Table 1, entries 2–7). The model reaction was
easier and gave the highest yield in a solvent-free condition. To
optimize the catalyst amount, the model reaction was carried
out in the presence of various amounts of the catalyst, and
according to the obtained results, the optimum amount of the
catalyst was 0.04 g (Table 1, entry 12). In a reaction, without
catalyst, a low yield of the product was achieved aer a long
reaction time (Table 1, entry 1), and this indicates the high
efficiency of catalyst for this reaction. According to the results,
the best condition is using 0.04 g of the catalyst under the
solvent-free condition at room temperature with an electrical
mortar-heater (Table 1, entry 12).
Due to remarkable results from the above experiments, we
decided to synthesize naphtho[1,2-e][1,3]oxazines, and the
results are summarized in Table 2. The products were obtained
in good to excellent yields in short reaction times with aliphatic
and aromatic amines with electron-withdrawing/donating
substituents.
Aer the completion of the reaction, the reusability of the
catalyst was also investigated in the model reaction. It was
separated by ltration, washed 3 times with ethanol, and dried
ꢁ
in an oven at 50 C to provide an opportunity for recycling
experiments. The separated catalyst was reused in the
3 2
Fig. 5 Elemental mapping images of GA-OPO H .
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Table 1 The reaction of 2-naphthol (1 mmol), formalin (2 mmol) and aniline (1 mmol) under various conditions
a
b
Entry
Solvent
Catalyst (g [mmol])
Condition
Time (min)
Yield (%)
c
1
2
3
4
5
6
7
8
9
—
—
r. t.
60
25
25
25
25
25
25
5
60
60
60
5
15
56
69
49
62
63
55
94
25
17
—
99
92
87
H
2
O
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.05 [0.33]
0.04 [0.26]
0.03 [0.2]
0.02 [0.13]
r. t.
r. t.
r. t.
r. t.
r. t.c
r. t.c
r. t.
C
2
H
5
OH
CHCl
CH CN
O : C
OH
3
3
H
2
2
H
5
OH (1 : 1)
CH
—
—
—
—
—
—
—
3
ꢁ
c
c
c
50 C
ꢁ
10
11
12
13
14
60 C
ꢁ
80 C
c
r. t. c
r. t. c
r. t.
5
5
a
b
c
GA-OPO
3
H
2
.
Isolated yield. Electrical mortar-heater.
a
3 2
Table 2 Synthesis of naphtho[1,2-e][1,3]oxazines in the presence of GA-OPO H under solvent-free condition at room temperature
b
ꢁ
Entry
R
C
Product
Time (min)
Yield (%)
MP ( C)
1
2
3
4
5
6
7
8
9
6
H
5
–
4a
4b
4c
4d
4e
4f
4g
4h
4i
9
99
94
91
97
97
95
91
90
97
94
92
94
95
45–47 (ref. 22)
86–88 (ref. 22)
44–46 (ref. 21)
116–118 (ref. 22)
100–104 (ref. 21)
76–78 (ref. 22)
124–125 (ref. 21)
72–73 (ref. 21)
233(d) (ref. 21)
98–100 (ref. 21)
4-Me–C
4-Et–C
4-Br–C
4-Cl–C
4-OMe–C
–CH
2-Cl–C
–CH
6
H
H –
4
4
–
10
10
9
9
9
10
11
9
6
6
H
4
–
–
6
H
4
6
H
4
–
C
6
H
5
2
-
6
H
4
–CH
2
-
2
-
C
6
H
5
2
–CH
10
11
12
13
2-Furyl–CH
Cyclohexyl-
n-Butyl–
2
–
4j
4k
4l
9
c
11
11
11
250(d) (ref. 21)
170(d) (ref. 21)
178(d) (ref. 21)
c
c
n-Hexyl–
4m
a
b
c
3 2
The amount ratio of 1 (mmol) : 2 (mmol) : 3 (mmol): GA-OPO H (mmol) is equal to 1 : 2 : 1 : 0.26. Isolated yield. Decompose.
mentioned reaction ve times without considerable loss of its
The efficiency of the GA-OPO
3 2
H catalyst in comparison with
catalytic activity (Fig. 7).
some previously reported ones for the synthesis naphtho[1,2-e]
The separated catalyst was reused in the mentioned reaction [1,3]oxazines are summarized in Table 3. As Table 3 indicates,
ve times without considerable loss of its catalytic activity the use of GA-OPO H has remarkably improved the synthesis

3
2
(Fig. 7 and 3c).
of naphtho[1,2-e][1,3]oxazines in different terms such as
simplicity of protocol with compatibility with the environment.
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The suggested mechanism for the synthesis of naphtho[1,2-
e][1,3]oxazines has been shown in Scheme 2. The GA-OPO H2
3
catalyst operates as a Brønsted acid and at rst, actuates the
carbonyl group in formaldehyde. Then, the Mannich-type
condensation of amine (3) with formaldehyde (2) gives imine
I, which was attacked by the electron-rich center of 2-naphthol
(1) to form intermediate II. Intermediate II, via a second
Mannich-type condensation with a second molecule of form-
aldehyde, gives intermediate III, which through intramolecular
cyclization afforded product (4).
Fig. 7 Catalyst recycling experiments.
Conclusions
3 2
Table 3 Comparison of the efficiency of the GA-OPO H catalyst with
other reported catalysts for the synthesis of naphtho[1,2-e][1,3]oxa-
zines (4a)
3 2
In conclusion, we have introduced GA-OPO H as a highly effi-
cient, eco-friendly, inexpensive, and natural-based heteroge-
neous catalyst. The invented catalyst conveniently catalyzed the
synthesis of naphtho[1,2-e][1,3]oxazine derivatives via a one-pot
three-component reaction of 2-naphthol, formalin, and aniline
using GA-OPO H under the solvent-free condition at room
Conditions
Time
(min) Yield (%)
ꢁ
d
Entry Solvent/temp( C)/catalyst
3
2
a
1
2
3
4
5
6
7
H
2
O/r.t. /KAl(SO
4
)
2
$12H
2
O
15
0.5
1
75 (ref. 22)
80 (ref. 23)
77 (ref. 24)
89 (ref. 27)
65 (ref. 26)
92 (ref. 29)
temperature with an electrical mortar-heater. Short reaction
time and excellent yields are among the advantages of this novel
methodology.
—/r.t/ZrOCl
—/r.t/[bnmim][HSO
—/r.t/(PEG)
O/r.t/thiamine hydrochloride (VB
O/r.t/nano-Al /BF /Fe
2
b
4
]
c
5
H
H
2
1
)
60
20
9
2
2
O
3
3
3 4
O
—/r.t./GA-OPO
3
H
2
99 (this work) Experimental
a
b
Room temperature.
sulphate. Polyethylene glycol. Isolated yield.
1-Benzyl-3-methyl imidazolium hydrogen Materials and methods
c
d
All compounds were purchased from Merck, Aldrich, and Fluka
chemical companies and used without any additional
Scheme 2 Proposed mechanism for the synthesis of naphtho[1,2-e][1,3]oxazines.
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purication. The electrical mortar-heater that was used for the
grinding of the reaction mixture, was purchased from Borna-
Kherad Co., Iran, Yazd. FT-IR spectra were recorded on
a Bruker, Equinox 55 spectrometer. A Bruker (DRX-400 Avanes)
NMR was used to record the H-NMR and C-NMR spectra.
Melting points were determined by a Buchi melting point B-540
B. V. CHI apparatus and were uncorrected. X-ray diffraction
3 P. S. Gils, D. Ray and P. K. Sahoo, Int. J. Biol. Macromol., 2010,
46, 237.
4 M. Ling, H. Zhao, X. Xiaoc, F. Shi, M. Wu, J. Qiu, S. Li,
X. Song, G. Liu and S. Zhang, J. Mater. Chem. A, 2015, 3, 2036.
5 A. Khazaei, S. Rahmati, A. Ghaderi and L. Roshani, J. Iran.
Chem. Soc., 2014, 11, 263.
1
13
6 T. Baran and A. Mente ¸s , Int. J. Biol. Macromol., 2020, 161,
1559.
(XRD) patterns were obtained by a Philips Xpert MPD diffrac-
ꢀ
tometer equipped with a Cu Ka anode (k ¼ 1.54 A) in the 2q
7 B. Sreedhar, P. Surendra Reddy and D. Keerthi Devi, J. Org.
Chem., 2009, 74, 8806.
ꢁ
ꢁ
range from 10 to 80 . Quantitative elemental information and
maps of GA-OPO H were studied via energy-dispersive X-ray
spectroscopy (EDS) by a Phenom pro X instrument. Thermal
gravimetric analysis (TGA) was conducted using a “Universal
8 C. Wu and D. Chen, Nanoscale Res. Lett., 2012, 7, 317.
9 B. Sreedhar, P. S. Reddy and D. K. Devi, J. Org. Chem., 2009,
74, 8806.
3
2
V4.5A TA” instrument. The morphology was studied using 10 S. L. Favaro, F. D. Oliveira, A. V. Reis, M. R. Guilherme,
a Philips XL30 scanning electron microscope (SEM).
E. C. Muniz and E. B. Tambourgi, J. Appl. Polym. Sci., 2008,
07, 1500.
1
1
1 A. T. Paulino, M. R. Guilherme, L. H. C. Mattoso and
E. B. Tambourgi, Macromol. Chem. Phys., 2010, 211, 1196.
2 V. Kattumuri, S. KattiK Bhaskaran, E. J. Boote, S. W. Casteel,
G. M. Fent, D. J. Robertson, M. Chandrasekhar, R. Kannan
and K. V. Katti, Nano.Micro.Small, 2007, 3, 333.
Preparation of GA-OPO H
3
2
GA is an exudate from the Acacia tree. Then, the catalyst (GA-
1
OPO H ) is simply prepared by adding P O (3 g) in the n-hexane
3
2
2 5
solution (5 ml) containing gum arabic (1 g). The mixture was
ꢁ
stirred for 10 min at 68 C. The mixture is sticky; hence, we have
1
1
1
3 J. Chyli n´ ska, T. Urba n´ ski and M. Mordarski, J. Med. Chem.,
added dichloromethane (5 ml) to make it into a powder. The
resulted suspension was ltered and washed 2 times with
acetonitrile to remove unreacted P
temperature.
1963, 6, 484.
4 B. P. Mathew, A. Kumar, S. Sharma, P. K. Shukla and
M. Nath, Eur. J. Med. Chem., 2010, 45, 1502.
5 A. J. Cocuzza, D. R. Chidester, B. C. Cordova, S. Jeffrey,
R. L. Parsons, L. T. Bacheler, S. Erickson-Viitanen,
G. L. Trainor and S. S. Ko, Bioorg. Med. Chem. Lett., 2001,
11, 1177.
2 5
O and dried at room
General procedure the synthesis of naphtho[1,2-e][1,3]
oxazines
1
1
6 T. Kurz, Tetrahedron, 2005, 61, 3091.
7 M. Kajino, Y. Shibouta, K. Nishikawa and K. Meguro, Chem.
Pharm. Bull., 1991, 39, 2896.
A mixture of 2-naphthol (1 mmol), formalin (2 mmol), primary
amine (1 mmol), and GA-OPO H (0.04 g) was stirred under the
solvent-free condition at room temperature with an electrical
mortar-heater. Aer the completion of the reaction (monitored
by TLC, n-hexane: EtOAc (4 : 1)), the reaction mixture was dis-
solved in hot ethanol (4 ml), and the catalyst was separated via
3
2
1
1
2
8 B. O. Buckman, R. Mohan, S. Koovakkat, A. Liang, L. Trinh
and M. M. Morrissey, Bioorg. Med. Chem. Lett., 1998, 8, 2235.
9 Y. Katsura, S. Nishino and H. Takasugi, Chem. Pharm. Bull.,
1991, 39, 2937.

ltration. Aer the evaporation of the solvent, the crude prod-
0 J. N. Joyce, S. Presgraves, L. Renish, S. Borwege, T. Osredkar,
D. Hagner, M. Replogle, M. PazSoldan and M. J. Millan, Exp.
Neurol., 2003, 184, 393.
ucts were recrystallized from ethanol to give pure naphtho-1,3-
oxazine derivatives. The recovered catalyst was washed 3 times
ꢁ
with ethanol, dried in an oven at 50 C, and then reused
2
2
1 S. Azad and B. F. Mirjalili, Mol. Diversity, 2019, 23, 413.
2 S. A. Sadaphal, S. S. Sonar, B. B. Shingate and M. S. Shingare,
Green Chem. Lett. Rev., 2010, 3, 213.
successfully.
Conflicts of interest
2
3 A. H. Kategaonkar, S. S. Sonar, R. U. Pokalwar,
A. H. Kategaonkar, B. B. Shingate and M. S. Shingare, Bull.
Korean Chem. Soc., 2010, 31, 1657.
There are no conicts to declare.
2
2
2
2
4 A. H. Kategaonkar, S. S. Sonar, K. F. Shelke, B. B. Shingate
and M. S. Shingare, Org. Commun., 2010, 3, 1.
5 P. V. Shinde, A. H. Kategaonkar, B. B. Shingate and
M. S. Shingare, Chin. Chem. Lett., 2011, 22, 915.
6 V. D. Dhakane, S. S. Gholap, U. P. Deshmukh, H. V. Chavan
and B. P. Bandgar, C. R. Chim., 2014, 17, 431.
Acknowledgements
The Research Council of Yazd University gratefully acknowl-
edged for the nancial support for this work.
7 A. Y. Shen, C. T. Tsai and C. L. Chen, Eur. J. Med. Chem.,
References
1999, 34, 877.
1
P. Mao, M. Zhao, F. Zhang, Y. Fang, G. O. Phillips, 28 P. D. Woodgate, G. M. Horner, N. P. Maynard and
K. Nishinari and F. Jiang, Carbohydr. Polym., 2013, 98, 699. C. E. Rickard, J. Organomet. Chem., 1999, 592, 180.
S. A. Fazeli-Attar and B. F. Mirjalili, Environ. Chem. Lett., 29 E. Babaei and B. F. Mirjalili, Polycyclic Aromat. Compd., 2019,
018, 16, 671. DOI: 10.1080/10406638.2019.1600561.
2
2
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