Solvent-free mechanochemical multicomponent preparation of 4H-pyrans catalyzed by Cu₂(NH₂-BDC)₂(DABCO) metal-organic framework

Abstract

4H-pyrans have been prepared through a mechanochemical multicomponent reaction (MCR) of different aldehydes, malononitrile, and various 1,3-dicarbonyl compounds, catalyzed by an amine-functionalized metal-organic framework (MOF) Cu₂(NH₂-BDC)₂(DABCO) as a heterogeneous catalyst with good to excellent yields.

Graphical abstract

1. Introduction

Pyrans are non-aromatic heterocyclic six-membered rings with a molecular formula of RC₅H₆O, including five carbon atoms, one oxygen atom, and two double bonds. The two isomers of the pyrans differ in the double bond position. In 2H-pyran (1), saturated sp3 carbon is positioned at position 2, but in 4H-Pyran (2), it is at position 4 (Scheme 1). In 1962, 4H-pyrans were created for the first time through the thermal decomposition of 2-acetoxy-3,4-dihydro-2H-pyran, and their properties and applications were investigated [1,2].

Scheme 1.

2H-Pyran and 4H-Pyran.

Heterocyclic compounds, including tetrahydrobenzo[b]pyrans and their derivatives, have been studied for their potential medicinal and pharmacological applications (see, for example, Scheme 2) [3]. They have attracted special attention, which can be attributed to their antioxidant [4], anticancer [5], antitumor [6] properties, etc. Tetrahydrobenzo[b]pyran-based compounds possess the potential for physical enhancers in treating neurological diseases such as Alzheimer's and Parkinson's diseases, Dawson's syndrome, amyotrophic lateral sclerosis, Huntington, Schizophrenia, AIDS-associated dementia, and myoclonus [7]. Also, these compounds are widely used in cosmetics and as pigments [8].

Scheme 2.

Pyran-based natural and synthetic drugs in clinical use [3].

Various methods have been reported to prepare tetrahydrobenzo[b]pyrans and their derivatives. Generally, the basis of their synthesis is the three-component condensation of variable 1,3-dicarbonyl derivatives, CH-active compounds, and aldehydes. Various heterogeneous and homogeneous catalysts have been reported so far for this condensation reaction, including magnetite l-proline [9], DABCO-CuCl complex [10], trisodium citrate [11], cesium carbonate [12], ninhydrin [13], ionic liquids based on choline hydroxide [Ch]⁺[OH]^- [14] or DABCO [H₂-DABCO][H₂PO₄]₂} [15], starch solution [16], sulfonic acid functionalized silica [17], Fe(ClO₄)₃/SiO₂ [18], ClO₄⁻/Al-MCM-41 [19], poly(4-vinyl pyridine) (P4VP) [20], and silica-supported dodeca-tungstophosphoric acid DTP/SiO₂ [21]. These methods may have disadvantages and problems, including using complex, toxic and destructive catalysts, tedious and challenging purification processes, low efficiency, and slow reaction rates.

Crystalline compounds are known as metal-organic frameworks (MOFs), composed of inorganic moieties (metal ions/clusters) and organic linkers, creating a porous structure of different dimensions (Scheme 3) [[22], a), b)]. They have a low density, a large surface area, and a high proportion of catalytically active transition metals. Most often, metals in the lattice of MOFs act as Lewis acids. The solvent type, solvent concentration, opposite ion nature, metal-to-ligand ratio, metal quadratic geometry, pH, temperature, and the nature of guest molecules determine the MOF structure [[22], [23], [24], [25], [26], [27], [28]]. MOFs have many applications in drug delivery, sensors and luminescence, gas separation and storage, and catalytic reactions [[29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40]].

Scheme 3.

General scheme of MOF synthesis.

Mechanochemical reactions are considered nowadays as green methods of chemical synthesis. Among the others, ball-milling has been a widely accepted tool for solvent-free mechanochemical reactions in recent years. The ball milling method has numerous benefits over other procedures, including quick reaction times, solvent-free settings, high yields, and high atom efficacy [[41], a), b), c), d)]. Based on successful organic synthesis through ball milling in previous studies [[42], a), b), c), d)], Herein, we presented a three-component, solvent-free synthesis of 4H-pyrans derivatives using ball-milling with nanoporous Cu₂(NH₂-BDC)₂(DABCO) as a heterogeneous catalyst with good to excellent yields (Scheme 4). These kinds of reactions can be considered as a base-catalyzed as well as an acid-catalyzed reactions. We have chosen Cu₂(NH₂-BDC)₂(DABCO), to have a bifunctional catalyst, namely both a Lewis acid Cu²⁺, as well as Lewis base NH₂ in a unique catalyst. The better activity of this catalyst has been shown in comparison to other catalysts.

Scheme 4.

The heterogeneous catalysis of Cu₂(NH₂-BDC)₂(DABCO) in a three-component, solvent-free synthesis of 4H-pyran derivatives.

2. Experimental section

2.1. Materials and reagents

All chemicals, such as 2-aminoterephthalic acid (NH₂-BDC), 1,4-diazabicyclo[2.2.2]octane (DABCO), metal salt Cu(OAc)₂.H₂O, aldehydes, and 1,3-dicarbonyl components were obtained through Sigma-Aldrich and Merck companies in reagent grade for direct use without additional purification. As eluents, EtOAc and n-hexane (1:1 or 1:2) were used for thin-layer chromatography (TLC).

2.2. Instrumental

Melting points have been measured using open capillaries (sealed at one end) using an Electrothermal 9100 instrument. FT-IR spectra were collected using a Shimadzu 8400S spectrometer. Spectra of ¹HNMR were obtained using a Bruker 500 MHz spectrometer. DMSO‑d₆ was used as solvent at ambient temperature. Using an X'pert MPD, XRD observations were conducted. Philips diffractometer with Cu radiation source (λ = 1.54050A) operating at 40 mA and40 KV. A MM400 Retsch ball milling device with two 10 mL jars and 7 mm stainless steel balls was utilized at a frequency of 28 Hz.

2.3. Synthesis of Cu₂(NH₂-BDC)₂(DABCO)

With a molar ratio of 2:2:1, 0.6 mmol of Cu(OAc)₂.H₂O, 0.6 mmol of NH₂-BDC, and 0.3 mmol of DABCO were forcefully grinded through solvent-free ball-milling (28 Hz) at ambient temperature for 2 h. This resulted in a green product washed three times with DMF (3 × 10 mL). Methanol was used for solvent exchange three times (10 mL each) at ambient temperature. In order to eliminate methanol molecules, the obtained powdered MOF was heated at 130 °C under a vacuum for 12 h [42].

2.4. Preparation of 2-amino-3-cyano-4H-pyran derivatives (5, 6, 8, or 9) zcatalyzed by Cu₂(NH₂-BDC)₂(DABCO)

In order to synthesize 2-amino-3-cyano-4H-pyran derivatives (5, 6, 8, or 9), a mixture of malononitrile (1 mmol), Cu₂(NH₂-BDC)₂(DABCO) (0.04 g), 1,3-dicarbonyl components (1 mmol), and aldehyde (1 mmol) was grinded through ball-mill forcefully at 27 Hz, at ambient temperature and solvent-free for the indicated intervals. After the reaction (monitored by TLC) was complete, the catalyst was separated by filtration, washed with (hot) ethanol, and dried for reuse. The product was obtained in pure form after evaporation of EtOH or recrystallization, if necessary.

3. Results and discussion

3.1. Synthesis and characterization of Cu₂(NH₂-BDC)₂(DABCO)

Following the previously reported procedure, a combination of DABCO, copper (II) acetate, and 2-aminoterephthalic acid in a molar ratio of 1:2:2 was grinded using a ball mill at ambient temperature without the use of any solvent to produce the metal-organic framework Cu₂ (NH₂-BDC)₂(DABCO) [42] (Scheme 5). The synthesis was finished in less than 2 h, yielding a green powder. Various methods were used to characterize the resultant MOF, including X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR).

Scheme 5.

Ball mill synthesis of Cu₂(NH₂-BDC)₂(DABCO).

The as-synthesized XRD pattern of Cu₂(NH₂-BDC)₂(DABCO) is shown in Fig. 1a,b. The significant peaks at 2θ values of 8, 9, 11, 12, and 16 align well with the previously reported data [42]. Comparing the patterns demonstrated the successful synthesis of a pure Cu₂(NH₂-BDC)₂(DABCO).

Fig. 1.

XRD pattern of a) the prepared Cu₂(NH₂-BDC)₂(DABCO) in this work, b) Simulated XRD pattern [42].

To describe the vibrational modes of the MOF, FT-IR spectroscopy was performed. Fig. 2 depicts the FT-IR spectrum of Cu₂(NH₂-BDC)₂(DABCO), NH₂-BDC, and DABCO. The asymmetric COO stretch mode (ν_as) is observed at 1614 cm⁻¹, whereas CO symmetric stretching is observed at 1377 cm⁻¹. The absorption bands at 3359 and 3469 cm⁻¹ correspond to two NH stretching bands of –NH₂ groups.

Fig. 2.

FT-IR spectra: a) 2-aminoterephthalic acid, b) DABCO, c) Cu(OAc)₂, d) Cu₂(NH₂-BDC)₂(DABCO).

The average particle size of the synthesized Cu₂(NH₂-BDC)₂(DABCO) samples were determined to be less than 100 nm based on scanning electron microscopy (SEM) images. (Fig. 3a). Transmission electron microscopy was utilized to examine the morphology of Cu₂(NH₂-BDC)₂(DABCO) (TEM). As depicted in Fig. 3b nano-scaled and crystalline material was generated. It is also important to note that the ball milling approach produced nanoparticles with the consistent distribution. As seen in the TEM photos, the presence of square units indicates the production of Cu₂(NH₂-BDC)₂(DABCO) frameworks, consistent with the SEM images confirming the nano-cubic shape. Cu was detected in the particles of Cu₂(NH₂-BDC)₂(DABCO) using energy dispersive X-ray spectroscopy (EDS) (Fig. 3c).

Fig. 3.

a) FESEM photographs, b) TEM photographs, c) EDS analysis and d) TGA spectra of Cu₂(BDC)₂(DABCO).

TGA was used to examine the thermal breakdown of Cu₂(NH₂-BDC)₂(DABCO) at temperatures up to 500 °C at a heating rate of 10 °C min⁻¹ in N₂ flow (Fig. 3d). Cu₂(NH₂-BDC)₂(DABCO) is stable up to 245 °C, and demonstrates distinct zones of weight loss commencing at approximately 110–150 °C (3.97% due to the loss of DMF and H₂O. This step of the TGA study (starting at approximately 245 °C) demonstrates the decomposition of linkers (Fig. 3d). The storage capacity of molecules in the pores and channels of MOFs was evaluated using the Brunauer-Emmett-Teller (BET) technique. Based on the findings, the Cu₂(NH₂-BDC)₂(DABCO) specific surface area was 143.35 ± 3.5 m²g^-1, mesopore diameter at maximum pore volume was 19.568 nm, and total pore volume was 0.629 cm³ g⁻¹in Cu₂(NH₂-BDC)₂(DABCO). These results show that the catalyst includes many pores and channels which can be effective in catalytic functions. The average crystal size which has been represented in Fig. 7 based on XRD calculation, was 95.2 nm.

Fig. 7.

X-ray diffraction of powder of Cu₂(NH₂-BDC)₂(DABCO): a) Fresh catalyst, b) Recovered catalyst after 6th runs.

3.2. Catalytic properties of Cu₂(NH₂-BDC)₂(DABCO)

To evaluate the catalytic properties of Cu₂(NH₂-BDC)₂(DABCO) in synthesizing 4H-pyran compounds, the three-component condensations of stoichiometric amounts of dimedone, 4-chlorobenzaldehyde, and malononitrile was studied. The findings data are reported in Table 1. The model reactions were investigated in a variety of solvents, including EtOH, THF, and CH₃CN, using Cu₂(NH₂-BDC)₂(DABCO) loading of 0.04 g at 75 °C temperature. The use of acetonitrile and tetrahydrofuran solvents resulted in increased reaction time and reduced efficiency; however, using ethanol as a solvent caused reduced reaction time and increased efficiency.

Table 1.

Optimizing the three-component reaction of 4-chlorobenzaldehyde (2a), malononitrile (3), and dimedone (4a) under various conditions.

.

Entry	Catalyst loading	Solvent	Temp. (°C)	Time (min)	Yieldb (%)
1	0.04	THF	75	360	68
2	0.04	MeCN	75	300	85
3	0.04	EtOH	75	20	90
4	0.04	EtOH	50	30	85
5	0.04	EtOH	r.t	45	80
6	–	Solvent-free	r.t	80	88
7	0.02	Solvent-free	r.t	26	90
8	0.04	Solvent-free	r.t	5	96
9	0.04	Solvent-free	r.t	20	78

^a Conditions of reaction: 4-chlorobenzaldehyde (2a, 1.0 mmol), malononitrile (3, 1.0 mmol), dimedone (4a, 1.0 mmol), grinding, ambient temperature.

^bYield refers to isolated products.

It was then examined how temperature affected yield and reaction time. It was shown in Table 1 that low temperatures reduce the efficiency and decrease the reaction speed. The solvent and reaction temperature zoptimization indicated that a higher yield could be achieved in EtOH using a reflux condition over a shorter period. The solvent-free condition has shown that the reaction was carried out in the shortest possible time and with the highest efficiency (entry 6). The turnover frequency (TOF) of the reaction has been calculated based on the following equation:

$$TOF=\frac{Numberofmolesofreactantconsumed}{Moleofcatalyst}$$

The TON (Turnover number) indicates the maximum number of molecular reactions or reaction cycles that can occur at a catalyst's reactive centre before the activity of the catalyst begins to degrade. It has been calculated as:

$$TON=TOF\left[{time}^{-1}\right]$$

Based on these equations, for the optimal conditions (Entry 8), the TOF was calculated as 15, and the TON as 5*10⁻² s⁻¹.

Generally, the ball milling method, except for the purification of the product, if necessary, no solvent is used, and hence it is considered a green synthetic method. Furthermore, the role of catalyst payload on reaction termination was studied. The best and highest yields are obtained with 0.04 g of catalyst (entry 8). The same reaction was performed with Cu₂(BDC)₂(DABCO) as a non-NH₂ catalyst at a relatively higher time and with lower efficiency (entry 9).

To illustrate the extent of the usability of this catalyst, we expanded the zoptimized reaction conditions to various aldehydes and 1,3-cyclohexanedione compounds. Table 2 shows a summary of the findings. As shown in the table, the highest yield was obtained for producing products 5 and 6 under optimal conditions progressively. In addition, the catalyst was simply isolated by filtration and removed from the reaction mixture.

Table 2.

Preparation of 4H-pyrans derivatives by using Cu₂(NH₂-BDC)₂(DABCO) as the catalyst^a

.

Entry	Aldehyde	Product	Time (min)	Yield (%)b	M. P. (°C)	M.P. (°C) [Lit.]
1	4-Chloro benzaldehyde	5a	5	96	212–214	212-214 [45]
2	2-Chloro benzaldehyde	5b	6	93	209–212	211-213 [46]
3	4- Bromo benzaldehyde	5c	8	96	204–207	205-206 [43]
4	Benzaldehyde	5d	12	90	223–226	222-224 [44]
5	2-Nitro benzaldehyde	5e	9	94	215–218	213-217 [15]
6	3-Nitro benzaldehyde	5f	6	90	214–216	216-218 [47]
7	4-Nitro benzaldehyde	5g	7	92	180–184	180-182 [48]
8	4-Methyl benzaldehyde	5h	20	90	217–220	215-217 [48]
9	3-Hydroxy benzaldehyde	5i	23	88	203–206	205-206 [49]
10	4-Hydroxy benzaldehyde	5j	25	85	206–209	205-206 [50]
11	2,4-Dichloro benzaldehyde	5k	6	94	189–192	192-194 [44]
12	4-Cyano benzaldehyde	5l	8	95	220–224	221-224 [50]
13	4-Chloro benzaldehyde	6a	20	94	242–244	241-244 [50]
14	2-Chloro benzaldehyde	6b	25	90	210–212	210-212 [51]
15	4- Bromo benzaldehyde	6c	22	90	235–237	236-238 [52]
16	Benzaldehyde	6d	40	86	237–240	241-242 [53]
17	2-Nitro benzaldehyde	6e	25	85	198–200	197-199 [54]
18	3-Nitro benzaldehyde	6f	30	92	234–237	234-236 [52]
19	4-Nitro benzaldehyde	6g	20	88	223–225	222-224 [52]
20	4-Methyl benzaldehyde	6h	40	90	224–228	225-226 [44]
21	2,4-Dichloro benzaldehyde	6i	23	89	220–223	221-223 [13]
22	4- Hydroxy benzaldehyde	6j	42	86	246–248	244-246 [50]

^aReaction conditions: aldehyde (2, 1.0 mmol), malononitrile (3, 1.0 mmol), dimedone or 1,3-cyclohexandione (4a-b, 1.0 mmol), Cu₂(NH₂-BDC)₂(DABCO) (0.04 g), solvent-free and room temperature.

^bIsolated yield.

In the next step, ethyl acetoacetate was used as the changeable component for extending the scope of the protocol to the less active reagents. A summary of the data can be found in Table 3. It should be noted that in addition to ethyl acetoacetate, acetylacetone was also studied. Under optimum reaction conditions, the good and desirable yield of the intended products (5, 6, 8, and 9) was achieved within a brief reaction time.

Table 3.

Preparation of 4H-pyrans derivatives by using Cu₂(NH₂-BDC)₂(DABCO) as the catalyst^a

.

Entry	Aldehyde	Product	Time (min)	Yield (%)b	M.P. (°C)	M.P. (°C) [Lit.]
1	4-Chloro benzaldehyde	8a	22	92	160–163	162 [55]
2	2-Chloro benzaldehyde	8b	25	90	188–192	190-191 [56]
3	4-Bromo benzaldehyde	8c	25	92	179–182	179-180 [57]
4	Benzaldehyde	8d	60	80	185–188	189 [58]
5	2-Nitro benzaldehyde	8e	42	90	178–180	177-178 [57]
6	3-Nitro benzaldehyde	8f	40	87	186–190	187-188 [57]
7	4-Nitro benzaldehyde	8g	40	89	175–178	174-176 [59]
8	4-Methyl benzaldehyde	8h	18	90	173–176	175-176 [59]
9	4-Chloro benzaldehyde	9a	30	65	149–154	153-155 [60]
10	3-Nitro benzaldehyde	9b	42	63	160–164	166 [61]

^aReaction conditions: aldehyde (2, 1.0 mmol), malononitrile (3, 1.0 mmol), acetyl acetone or ethyl acetoacetate (7a-b, 1.0 mmol), Cu₂(NH₂-BDC)₂(DABCO) (0.04 g), solvent-free and room Temperature.

^bIsolated yield.

Physical and spectroscopic data were compared to those of previously described compounds in the literature, allowing the clear labelling of all products. In FT-IR spectra of the products, the significant band at around 2190 cm⁻¹ is related to the CN stretching band, and the broad band at 3200-3400 cm⁻¹ approves the presence of the NH₂ moiety (see Fig. 4d) [50]. As shown in Fig. 5 for the compound 6h, the characteristic H4 in ¹H NMR spectra of these compounds was appeared as a singlet above 4.0 ppm [50].

Fig. 4.

FT-IR spectra of 2-amino-3-cyano-4-(4-methylphenyl)-5-oxo-5,6,7,8-tetrahydro-4H-1-benzopyran (6h).

Fig. 5.

¹H NMR spectra of 2-amino-3-cyano-4-(4-methylphenyl)-5-oxo-5,6,7,8-tetrahydro-4H-1-benzopyran (6h).

A plausible mechanism has been suggested in Scheme 6. The first step consists of forming a cyanocinnamonitrile Knoevenagel intermediate in the reaction of by Cu²⁺-activated aldehyde reacting with malononitrile. At this stage, the catalyst Cu₂(NH₂-BDC)₂(DABCO) produces an anion by attacking the acid hydrogens of malononitrile. The produced anion is a nucleophile and attacks the carbonyl group of the aldehyde as an electrophile. Subsequently, by removing a water molecule, the Knoevenagel intermediate is formed. Then, 1,3-dicarbonyl components are added to the intermediate by Michael's addition of the enol form. Then the cyclization, and subsequent tautomerization of the imino-pyran intermediates is carried out on the amino-pyran.

Scheme 6.

The suggested mechanism of the 4H-pyrans derivatives synthesis using Cu₂(NH₂-BDC)₂(DABCO).

3.3. Catalytic properties of Cu₂(NH₂-BDC)₂(DABCO)

The recyclability and the reusability of Cu₂(NH₂-BDC)₂(DABCO) were also studied for a minimum of six rounds in the model reaction zsynthesizing the product 5a. A simple filtration process separated the catalyst from the reaction after each run. A summary of the results can be found in Fig. 6. It has been demonstrated that Cu₂(NH₂-BDC)₂(DABCO) is reusable without a substantial loss of activity in 4H-pyrans synthesis.

Fig. 6.

Reusability of Cu₂(NH₂-BDC)₂(DABCO) catalyst for the MCR synthesis of 4H-pyran 5a.

XRD and FT-IR techniques were used to zanalyze the structure of the retrieved catalyst, which showed no degradation (Fig. 7, Fig. 8b). The recovered catalyst's FT-IR spectra and x-ray pattern show that its crystalline structure remains intact and stable.

Fig. 8.

FT-IR spectra of powder of Cu₂(NH₂-BDC)₂(DABCO): a) Fresh catalyst, b) Recovered catalyst after 6th runs.

3.4. Comparison activity of Cu₂(NH₂-BDC)₂(DABCO)

The new methodology for synthesizing various 4H-pyran derivatives was assessed by comparing several previous reports and accepted methods to demonstrate its efficacy and capabilities. Table 4 provides a comprehensive summary of the results of the present protocol, demonstrating its superiority over other approaches with respect to the yield of the product, reaction time, non-using of organic solvents as green chemistry, as well as simplified separation and reusability of the catalyst.

Table 4.

A comparison of the previously reported procedures for the synthesis of chemicals 5a, 6f, and 8a.

Entry	Product	Catalyst	Catalyst loading	Solvent	Temp. (°C)	Time (min)	Yield (%)	Ref.
1	5a	Cu2(NH2-BDC)2(DABCO)	40 mg	Solvent-free	r.t	5	96	This work
2	5a	Cu2(BDC)2(DABCO)	40 mg	Solvent-free	r.t	20	78	This work
3	5a	NH4Al(SO4)2.12H2O (Alum)	20 mg	EtOH	80	120	94	[62]
4	5a	PhB(OH)2	5 mol%	H2O/EtOH	Reflux	30	84	[63]
5	5a	SiO2-Pr-SO3H	30 mg	H2O/EtOH	Reflux	15	97	[17]
6	5a	KF/Al2O3	250 mg	DMF	r.t	60–180	48	[60]
7	5a	MPA-MDAZYb	140 mg	EtOH	80	70	90	[64]
8	5a	ChCl/Urea DESc	1 mL	ChCl/Urea DESc	80	60–240	92	[65]
9	5a	Amberlyst A21	30 mg	EtOH	r.t	60	84	[66]
10	6f	Sodium Alginate	10 mol%	EtOH	Reflux	52	93	[67]
11	6f	MPA-MDAZYb	140 mg	EtOH	80	40	75	[64]
12	6f	Lipase from Porcine pancreas (PPL)	30 mg	H2O/EtOH	35	60	96	[68]
13	8a	ChCl/Urea DESc	1 mL	ChCl/Urea DESc	80	210	82	[65]
14	8a	Sodium Alginate	10 mol%	EtOH	Reflux	150	90	[67]
15	8a	nanocrystalline ZnO	10 mol%	H2O/EtOH	r.t	150	96	[61]

^a Entries 1–8: Obtained outcomes for the synthesis of molecule5a, Entries 9–11: Obtained outcomes for the synthesis of molecule6f, Entries 12–14: Obtained findings for 8a compound synthesis.

^b12-Molybdophosphoric acid (MPA), modified dealuminated zeolite Y (MDAZY).

^cDeep eutectic solvent (DES).

4. Conclusion

In this paper, we developed a highly effective, environmentally friendly, and greenway for the multicomponent synthesis of 4H-pyran derivatives in the presence of Cu₂(NH₂-BDC)₂(DABCO) as a heterogeneous and renewable catalyst. In addition to all of these, our method has many advantages, such as concise reaction time, the reaction at ambient temperature and non-solvent conditions, high yields of products, as well as easy separation of catalyst from the reaction mixture. It is noteworthy that the catalyst was synthesized in a solvent-free manner.

Author contribution statement

Zahra Akhlaghi, Mohammad R. Naimi-Jamal, Leila Panahi: Conceived and designed the experiments; Performed the experiments; Analyzed and interpreted the data; Contributed reagents, materials, analysis tools or data; Wrote the paper.

Mohammad G. Dekamin: Conceived and designed the experiments; Contributed reagents, materials, analysis tools or data.

Bahareh Farasati Far: Analyzed and interpreted the data; Wrote the paper.

Funding statement

Partial support by the Iran University of Science and Technology is acknowledged.

Data availability statement

Data will be made available on request.

Declaration of interest’s statement

The authors declare no conflict of interest.