Home Environmentally friendly synthesis and computational studies of novel class of acridinedione integrated spirothiopyrrolizidines/indolizidines
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Environmentally friendly synthesis and computational studies of novel class of acridinedione integrated spirothiopyrrolizidines/indolizidines

  • Rajesh Raju EMAIL logo , Raghavachary Raghunathan , Natarajan Arumugam EMAIL logo , Abdulrahman I. Almansour , Raju Suresh Kumar , P. A. Vivekanand , Cheriyan Ebenezer , Rajadurai Vijay Solomon and Karthikeyan Perumal
Published/Copyright: July 13, 2023
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Green Processing and Synthesis
From the journal Green Processing and Synthesis Volume 12 Issue 1

Abstract

An efficient and environmentally benign synthesis of a new class of acridinedione embedded spirooxindolo/acenaphthenothiopyrrolizidines and spirooxindolo/acenathenoindolizidines has been synthesized in good to excellent yields employing ionic liquid accelerated one-pot [3 + 2]-cycloaddition strategy. The pre-requisite starting substrates, O-acryloyl acridinediones were prepared from dimedone in three good yielding steps, while the 1,3-dipole was derived in situ from isatin/acenaphthenequinone and thiazolidine-4-carboxylc acid/l-pipecolinic acid via decarboxylative condensation. The cycloadduct possesses three stereogenic carbons, one of which is a spiro carbon through the formation of two C–C and one C–N bonds in one-pot synthetic transformation. Geometrical parameters of the synthesized compounds were calculated using the B3LYP/6-311g(d,p) level of theory. The activity of these molecules was evaluated against main protease of COVID-19 to screen them for their inhibitor efficiency. In order to get a broad understanding of the interactions of these synthesized ligands, a detailed molecular docking analysis was performed. Molecular docking analysis shows that compound 8b has the highest binding affinity toward the protein. The compound can be a potential candidate for the treatment of COVID-19.

Keywords: spirooxindolo/acenathenothiopyrrolidines; spirooxindolo/acenathenoindolizidines; acridinedione; ecofriendly green protocol; 1,3-dipolar cycloaddition

1 Introduction

Hybrid heterocycles play an essential role in drug discovery because of their presence in a significant number of drugs [1]. Heterocycles not only provide protein-binding functional groups, but also have a beneficial effect on drug solubility and its pharmacokinetic properties. Spiro compound-embedded heterocycles have emerged as particularly attractive synthetic targets in drug discovery because of their structural rigidity and inherent structural complexity and ability to expose functionality that offers enhanced affinity to biotargets [2]. In addition, the spiro compounds serve as useful molecular scaffolds for exploring and utilizing the pharmacophore space, which has led to the discovery of new drug leads. Spiro compounds containing acenaphthenone or oxindole moieties are of particular interest in medicinal chemistry because of their interesting biological properties, including antimicrobial, cholinesterase inhibitory activity, anticancer, and anti-mycobaterium tuberculosis activities [3–10]. Similarly, thiazolidine and indolizidine, an important class of heterocyclic motifs found in many naturally occurring alkaloids, has displayed a wide range of biological activities [11–14].

Among the typical synthetic transformations leading to the spiroheterocyclic hybrids, multicomponent 1,3-dipolar cycloaddition of electron-deficient exocyclic alkenes with 1,3-dipole, derived from non-enolizable diketones and α-amino acids, is the most widely accepted synthetic strategy [15–19] as it allows the creation of several bonds in one-pot synthetic transformation that led to facilitate exciting advantages such as (i) direct isolation of target product, (ii) minimal number of synthetic operation which in turn minimize the waste, (iii) atom economy and ease automization, and (iv) operational simplicity. In addition, this strategy aids the effective generation of a series of potent pharmaceutically stimulating drug like compounds and plays an essential role in combinatorial and diversity-oriented synthesis [20]. Incidentally, it is known that the acridine structural motif possesses multifarious biological activities [22–24] and is an active motif present in numerous alkaloids [25].

Recently, we have reported a series of acridinedione bridged hybrid spiroheterocycles employing cascade cycloaddition reaction process via decarboxylative condensation [21]. In continuation of our research in the cycloaddition process and the biological importance of the above spiro compounds encouraged us to attempt the preparation of series of structurally interesting new classes of heterocycles embedding acridinedione and spirooxindole/acenapthenothiopyrrolizidines/indolizidines employing single pot cycloaddition strategy. In our earlier study, we reported the synthesis of spiropyrrolidine/pyrrolizidines derived from N-methylglycine and l-proline by 1,3-dipolarcycloaddition strategy [21]. In the present investigation, herein we report the synthesis and computational studies of a structurally intriguing new class of acridinedione tethered spirooxindolothiopyrrolizidines/indolizidines and acenaphthenothiopyrrolizidines/indolizidines derived from thiazolidine-4-carboxylc acid/pipecolinic acid employing ionic liquid-assisted intermolecular cycloaddition cascade green reaction sequence. Furthermore, O-acryloyl acridinediones utilized as dipolarophile for cycloaddition reaction is relatively less explored in the literature. The reaction sequence has been described in the flow chart of Figure 1a and the synthetic approach for the preparation of spiro compounds from amino acids and α,ά-diketones as outlined in Figure 1b. It is important to note that new structural novelty and diversity will lead to the addition of some better biological activities that are of paramount importance in medicinal chemistry. On the other hand, computational methods have unlocked new ways in understanding the chemical properties of molecules using calculations as a substitute for experimental investigation. The computational approach is not laborious and can be achieved effortlessly. The recent effects of density functional theory (DFT) methods together with quantum chemical calculations are significant. As DFT is great in predicting the chemical and physical properties of molecules with great accuracy, it is one among the most effective and useful computational tools [26,27].

Figure 1 (a) Flow chart for synthesis of spirocycloadducts and (b) synthetic approaches for acridinedione tethered spiro heterocyclic analogs.
Figure 1

(a) Flow chart for synthesis of spirocycloadducts and (b) synthetic approaches for acridinedione tethered spiro heterocyclic analogs.

2 Materials and methods

2.1 General procedure for the synthesis of O-acryloylacridinedione dipolarophile, 5a–b

To a solution of acridinedione 4a–b (1.0 g, 2.6 mmol) in dry dichloromethane (DCM) (40 mL) kept at 0–5°C triethylamine was added (1 mL) followed by acryloyl chloride (0.24 g, 2.6 mmol). Then the reaction mixture was stirred at RT for 5 h and after completion of the reaction, as monitored by thin layer chromatography (TLC), the triethylamine hydrochloride was filtered off. Upon concentrating the filtrate under reduced pressure below 50°C, a viscous material was obtained. The viscous material was dissolved in DCM and made into a slurry with silica gel. Column chromatography over silica gel with 2% methanol in chloroform as eluent furnished the compound 5a–b.

2.1.1 4-(3,3,6,6-Tetramethyl-9-phenyl-3,4,6,7,9,10-hexahydro-1,8(2H,5H)acridinedione-10-yl)phenyl acrylate (5a)

Yield: 75%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.81 (s, 6H), 0.96 (s, 6H), 1.82–1.88 (d, 2H, J = 17.4 Hz), 2.15–2.18 (d, 4H, J = 7.8 Hz), 5.27 (s, 1H), 6.10–6.13 (d, 1H, J = 10.2 Hz), 6.33–6.42 (dd, 1H, J = 10.5 Hz), 6.66–6.71 (d, 1H, J = 17.4 Hz), 7.08–7.43 (m, 9H). 13C NMR (CDCl3, 75 MHz): δ 26.77, 29.73, 32.42, 41.83, 50.22, 114.77, 123.17, 125.98, 127.44, 127.83, 128.08, 133.62, 136.35, 146.02, 149.66, 150.91, 163.95, 195.80. Mass: m/z 495 (M+). Anal. calculated for C32H33NO4: C, 77.55%; H, 6.71%; N, 2.83%; Found: C, 77.66%; H, 6.80%; N, 2.96%.

2.1.2 4-(3,3,6,6,-Tetramethyl-9-(4-nitrophenyl)-3,4,7,9,10-hexahydro-1,8(2H,8H) acridinedione-10-yl)phenylacrylate (5b)

Yield: 79%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.81 (s, 6H), 1.12 (s, 6H), 1.84–1.90 (d, 4H, J = 17.4 Hz), 2.08–2.13 (d, 2H, J = 16.8 Hz), 2.17–2.19 (d, 4H, J = 6.0 Hz), 5.34 (m, 1H), 6.10–6.14 (d, 1H, J = 10.5 Hz), 66.33–6.42 (dd, 1H, J = 10.2, 10.5 Hz), 6.6–6.72 (d, 1H, J = 10.8 Hz), 7.25–7.28 (m, 3H), 7.39–7.61 (m, 3H), 8.07–8.14 (m, 2H). 13C NMR (CDCl3, 75 MHz):δ 26.75, 29.23, 32.23, 40.84, 41.90, 50.04, 113.75, 114.54, 123.43, 127.38, 128.84, 129.36, 133.73, 135.94, 146.24, 150.27, 151.12, 153.44, 162.90, 195.64, 196.26. Mass: m/z 540 (M+). Anal. calculated for C32H32N2O6: C, 71.09%; H, 5.97%; N, 5.18%; Found: C, 71.20%; H, 6.07%; N, 5.27%.

2.2 General procedure for the synthesis of cycloadducts

A mixture of O-acryloylacridinedione dipolarophile 5a–b (1 mmol), thiazolidine-4-carboxylc acid 7/pipecolinic acid 9 (1 mmol) and isatin 6/acenapthenequinone (11) (1 mmol) were heated in [Bmim]Br (3 mL) for 1 h at 100°C. After completion of reaction (TLC), the reaction mixture was diluted with EtOAc (2 × 5 mL). The ethyl acetate layer was extracted and reduced under low temperature. The crude compounds were separated by column chromatography with chloroform–methanol (9:1) mixture to get the cycloadducts in good yields.

2.2.1 Spiro[2.3′]-oxindolo-3-[4″-(3,3,6,6-tetramethyl-9-phenyl-3,4,6,7,9,10-hexahydro-1,8(2H,5H) acridinedione-10-yl)phenyl]carboxylate thiopyrrolizidine (8a)

Yield: 92%. Yellow solid, mp 210–212°C;1H NMR (CDCl3, 300 MHz): δ 0.77 (s, 6H), 0.92 (s, 6H), 1.69–1.75 (d, 2H, J = 18.3 Hz), 1.94–2.00 (d, 2H, J = 17.4 Hz), 2.13–2.15 (d, 4H, J = 6.0 Hz), 2.32–2.44 (m, 1H), 2.54–2.62 (m, 1H), 3.01–3.05 (d, 1H, J = 11.7 Hz), 3.18–3.25 (m, 1H), 3.48–3.52 (d, 1H, J = 10.8 Hz), 3.90–3.93 (d, 1H, J = 10.8 Hz), 3.97–4.03 (dd, 1H, J = 6.6, 6.9 Hz), 4.34–4.37 (m, 1H), 5.24 (s, 1H), 6.40–6.43 (d, 2H, J = 8.4 Hz), 7.00–7.16 (m, 4H), 718–7.23 (m, 3H), 7.35–7.43 (m, 3H), 7.60–7.63 (d, 1H, J = 7.2 Hz), 9.05 (s, 1H). 13C NMR (CDCl3, 75 MHz): δ 26.74, 26.79, 29.67, 32.41, 32.56, 33.46, 38.17, 41.73, 50.14, 53.27, 54.97, 68.00, 73.97, 110.73, 114.72, 122.38, 122.89, 123.96, 126.03, 127.59, 127.78, 128.08, 130.45, 136.51, 142.23, 145.89, 149.79, 150.29, 168.44, 180.20, 196.08. Mass: m/z 713 (M+). Anal. calculated for C43H43N3O5S: C, 72.35%; H, 6.07%; N, 5.89%; Found: C, 72.44%; H, 6.18%; N, 5.96%.

2.2.2 Spiro[2.3′]-oxindolo-3-[4″-(3,3,6,6-tetramethyl-9-(4-nitrophenyl)-3,4,6,7,9,10-hexahydro-1,8(2H,5H)acridinedione-10-yl)phenyl]carboxylate thiopyrrolizidine (8b)

Yield: 87%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.783 (s, 6H), 0.961 (s, 6H), 1.74–1.80 (d, 2H, J = 17.4 Hz), 2.16–2.10 (d, 2H, J = 18.6 Hz), 2.03 (s, 4H), 2.30–2.41 (m, 1H), 3.18–3.24 (m, 1H), 3.48–3.52 (d, 1H, J = 10.8 Hz), 3.89–3.93 (d, 1H, J = 10.8 Hz), 3.96–4.00 (dd, 1H, J = 7.2 Hz), 4.07–4.14 (dd, 2H, J = 6.9 Hz), 4.32–4.34 (m, 1H), 5.26 (s, 1H), 6.45–6.47(d, 2H, J = 8.2 Hz), 7.00–6.97 (d, 1H, J = 7.8 Hz), 7.07–7.10 (m, 2H), 7.33–7.38 (t, 1H, J = 8.1, 7.8 Hz), 7.53 (m, 3H), 8.03 (s, 1H), 8.08–8.11 (d, 2H, J = 8.4 Hz), 10.38 (s, 1H). 13C NMR (CDCl3, 75 MHz): δ 31.41, 34.30, 36.11, 38.18, 42.92, 46.37, 54.70, 57.85, 65.01, 72.65, 78.35, 115.20, 118.04, 126.42, 128.10, 128.68, 132.08, 133.55, 134.97, 140.58, 147.87, 150.81, 155.20, 155.31, 158.26, 167.27, 200.43, 184.10, 173.27. Mass: m/z 758 (M+). Anal. calculated for C43H42N4O7S: C, 68.06%; H, 5.58%; N, 7.38%; Found: C, 68.15%; H, 5.65%; N, 7.49%.

2.2.3 Spiro[2.2′]-oxindolo-3-[4″-(3,3,6,6-tetramethyl-9-phenyl-3,4,6,7,9,10-hexahydro-1,8 (2H,5H)acridinedione-10-yl)phenyl]carboxylate indolizidine (10a)

Yield: 79%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.78 (s, 6H), 0.92 (s, 6H), 0.82 (m, 2H), 0.97 (m, 2H), 1.28–1.31 (m, 2H), 1.54–2.21 (m, 6H), 2.31–2.15 (d, 4H, J = 6.6 Hz), 2.29–2.50 (m, 2H), 3.26 (m, 1H), 3.69–3.76 (dd, 1H, J = 7.8 Hz), 5.24 (s, 1H), 6.45–6.43 (d, 2H, J = 6.0 Hz), 6.88–6.90 (d, 1H, J = 7.8 Hz), 7.01–7.04 (d, 2H, J = 9.0 Hz), 7.08–7.13 (m, 2H), 7.19–7.24 (t, 2H, J = 7.2, 7.8 Hz), 7.29–7.32 (m, 2H), 7.36–7.41 (m, 2H), 8.00 (s, 1H). 13C NMR (CDCl3, 75 MHz): δ 23.65, 25.64, 26.69, 29.56, 31.85, 32.85, 32.39, 33.49, 34.17, 41.71, 45.42, 49.95, 50.97, 59.49, 72.38, 109.58, 113.60, 122.94, 123.42, 126.01, 128.73, 129.01, 129.23, 129.48, 130.55, 135.80, 141.93, 146.12, 150.40, 150.54, 153.32, 170.09, 180.21, 195.79. Mass: m/z 709 (M+). Anal. calculated for C45H47N3O5: C, 76.14%; H, 6.67%; N, 5.92%; Found: C, 76.25%; H, 6.76%; N, 5.98%.

2.2.4 Spiro[2.3′]-oxindolo-3-[4″-(3,3,6,6-tetramethyl-9-(4-nitrophenyl)-3,4,6,7,9,10-hexahydro-1,8(2H,5H)acridinedione)phenyl]carboxylate indolizidine (10b)

Yield: 81%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.77 (s, 6H), 0.94 (s, 6H), 0.82–0.85 (m, 2H), 0.98–1.01 (m, 2H), 1.31–1.35 (m, 2H), 1.71–2.21 (m, 6H), 2.12–2.16 (d, 4H), 2.30–2.53 (m, 2H), 3.22–3.33 (m, 1H), 3.70–3.76 (dd, 1H, J = 8.1, 7.5 Hz), 5.31 (s, 1H), 6.46–6.49(d, 2H, 8.2 Hz), 6.87–6.90 (d, 1H, J = 7.8 Hz), 7.02–7.04 (d, 2H, J = 8.4 Hz), 7.08–7.13 (t, 1H, J = 7.2, 7.5 Hz), 7.30–7.35 (m, 2H), 7.53–7.61 (m, 3H), 7.78 (s, 1H), 8.09–8.12 (d, 2H, J = 8.4 Hz).13C NMR (CDCl3, 75 MHz): δ 23.72, 25.69, 26.74, 29.59, 31.89, 32.44, 33.54, 34.22, 41.77, 45.48, 49.98, 51.06, 59.53, 72.44, 109.62, 113.64, 122.95, 123.49, 126.00, 128.8, 129.34, 129.50, 130.61, 135.89, 141.96, 146.20, 150.44, 150.66, 153.40, 170.10, 180.26, 195.84. Mass: m/z 754 (M+). Anal. calculated for C45H46N4O7: C, 71.60%; H, 6.14%; N, 7.42%; Found: C, 71.72%; H, 6.26%; N, 7.54%.

2.2.5 Spiro[2.2′]-acenapthene-1′-one-3-[4″-(3,3,6,6-tetramethyl-9-phenyl-3,4,6,7,9,10-hexahydro-1,8(2H,5H)acridinedione-10-yl)phenyl]carboxylate thiopyrrolizidine (12a)

Yield: 80%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.73 (s, 6H), 0.88 (s, 6H), 1.52–1.59 (dd, 2H, J = 4.8 Hz), 1.80–1.87 (dd, 2H, J = 1.8, 2.1 Hz), 2.09–2.11 (d, 4H, J = 5.1 Hz), 2.45–2.57 (m, 1H), 2.63–2.72 (m, 1H), 3.09–3.14 (dd, 1H, J = 2.1, 2.4 Hz), 3.25–3.31 (m, 1H), 3.27–3.30 (d, 1H, J = 10.8 Hz), 3.85–3.88 (d, 1H, J = 10.8 Hz), 4.10–4.16 (dd, 1H, J = 6.6 Hz), 4.40–4.48 (m, 1H), 5.19 (s, 1H), 5.91 (d, 2H, J = 8.6 Hz), 6.81–6.84 (d, 2H, J = 9.0 Hz), 7.05–7.10 (t, 1H, J = 7.5 Hz, 7.2 Hz), 7.17–7.22 (t, 2H, J = 7.5 Hz), 7.31–7.33 (d, 2H, J = 7.2 Hz), 7.71–7.80 (m, 2H), 7.92–7.95 (d, 1H, J = 6.9 Hz), 8.00–8.02 (d, 1H, J = 8.1 Hz), 88.08–8.10 (d, 1H, J = 6.9 Hz), 8.17–8.20 (d, 1H, J = 8.1 Hz). 13C NMR (CDCl3, 75 MHz): δ 25.70, 28.65, 31.31, 32.79, 37.47, 40.59, 4 9.09, 52.47, 54.02, 67.40, 76.31, 113.62, 113.67, 120.87, 121.54, 123.54, 124.95 ,125.10, 126.75, 127.02, 127.35, 129.61, 130.52, 131.03, 132.04, 135.11, 141.73, 144.89, 148.42, 148.74, 167.43, 194.72, 203.91. Mass: m/z 748 (M+). Anal. calculated for C47H44N2O5S: C, 75.37%; H, 5.92%; N, 3.74%; Found: C, 75.45%; H, 6.02%; N, 3.86%.

2.2.6 Spiro[2.3′]-acenapthene-1′-one-3-[4″-(3,3,6,6-tetramethyl-9-(4-nitrophenyl)-3,4,6,7,9,10-hexahydro-1,8 (2H,5H)acridinedione-10-yl)phenyl]carboxylate thiopyrrolizidine (12b)

Yield: 83%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.78 (s, 6H), 0.91 (s, 6H), 1.53–1.59 (d, 2H, J = 17.2 Hz), 1.81–1.87 (d, 2H, J = 17.8 Hz), 2.13–2.17 (d, 4H, J = 6.2 Hz), 2.48–2.63 (m, 1H), 2.72–2.76 (m, 1H), 3.89–3.91 (d, 1H, J = 10.6 Hz), 3.28–3.39 (m, 2H), 3.89–3.91 (d, 1H, J = 10.6 Hz), 4.17–4.18 (dd, 1H, J = 6.8 Hz), 4.42–4.56 (m, 1H), 5.25 (s, 1H), 5.96–6.0 (d, 2H, J = 8.6 Hz), 6.85–6.87 (d, 2H, J = 9.2 Hz), 7.11–7.15 (t, 1H, J = 7.5 Hz), 7.22–7.27 (t, 2H, J = 7.8 Hz), 7.36–7.38 (d, 2H, J = 7.2 Hz), 7.7–7.85 (m, 2H), 7.97–8.01 (d, 1H, J = 7.2 Hz), 8.05–8.07 (d, 1H, J = 8.4 Hz), 8.13–8.15 (d, 1H, J = 7.2 Hz), 8.22–8.25 (d, 1H, J = 8.4 Hz). 13C NMR (CDCl3, 75 MHz): δ 25.72, 28.68, 31.35, 31.52, 32.83, 37.51, 40.62, 49.11, 52.49, 54.08, 67.43, 76.36, 113.65, 113.69, 120.90, 121.56, 123.58, 125.01, 125.20, 127.0, 127.38, 129.81, 130.57, 131.08, 132.07, 135.17, 141.78, 144.93, 148.45, 148.79, 167.48, 194.76, 203.97. Mass: m/z 793 (M+). Anal. calculated for C47H43N3O7S: C, 71.10%; H, 5.46%; N, 5.29%; Found: C, 71.21%; H, 5.54%; N, 5.37%.

2.2.7 Spiro[2.2′]-acenapthene-1′-one-3-[4′-(3,3,6,6-tetramethyl-9-phenyl-3,4,6,7,9,10-hexahydro-1,8 (2H,5H)acridinedione-10-yl)phenyl]carboxylate indolizidine (13a)

Yield: 85%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.75 (s, 6H), 0.90 (s, 6H), 0.83–0.86 (m, 2H), 0.95–0.98 (m, 2H), 1.28–1.33 (m, 2H), 1.71–2.28 (m 6H), 2.10–2.12 (d, 4H, J = 5.7 Hz), 2.31–2.43 (m, 2H), 3.35–3.41 (m, 1H), 3.74–3.80 (dd, 14H, J = 7.8 Hz), 5.21 (s, 1H), 6.15 (m, 2H), 6.89–6.92 (d, 2H, J = 9.0 Hz), 7.08–7.11 (d, 1H, J = 7.5 Hz), 7.19–7.24 (t, 2H, J = 7.5 Hz), 7.33–7.36 (d, 2H, J = 7.2 Hz), 7.58–7.61 (d, 1H, J = 6.9 Hz), 7.68–7.80 (m, 3H), 7.92–7.98 (m, 2H), 8.14–8.17 (d, 1H, J = 8.1 Hz). 13C NMR (CDCl3, 75 MHz): δ 23.74, 25.71, 26.78, 29.66, 31.90, 32.40, 32.60, 34.23, 41.74, 45.48, 46.00, 50.15, 51.04, 59.51, 72.40, 109.74, 114.73, 122.85, 123.17, 124.36, 125.91, 126.00, 127.13, 127.82, 128.08, 129.34, 129.48, 130.39, 136.32, 142.10, 145.95, 149.73, 150.46, 170.15, 180.26, 195.98. Mass: m/z 744 (M+). Anal. calculated for C49H48N2O5: C, 79.01%; H, 6.49%; N, 3.76%; Found: C, 79.12%; H, 6.60%; N, 3.88%.

2.2.8 Spiro[2.2′]-acenapthene-1′-one-3-[4″-(3,3,6,6-tetramethyl-9-(4-nitrophenyl)-3,4,6,7,9,10-hexahydro-1,8(2H,5H)acridinedione)phenyl]carboxylate indolizidine (13b)

Yield: 86%. Yellow solid, mp 210–212°C; 1H NMR (CDCl3, 300 MHz): δ 0.75 (s, 6H), 0.916 (s, 6H), 0.85 (m, 2H), 0.97 (m, 2H), 1.28–1.33 (m, 2H), 1.62–1.99 (m, 4H), 1.90–1.95 (m, 2H), 2.10–2.38 (d, 4H, J = 10.5 Hz), 2.20–2.24 (m, 2H), 2.35–2.44 (m, 2H), 3.37–3.38 (m, 1H), 3.75–3.81 (dd, 1H, J = 7.8 Hz), 5.29 (s, 1H), 6.16–6.23 (d, 1H, J = 8.5 Hz), 6.94–6.91 (d, 1H, J = 8.7 Hz), 7.51–7.54 (m, 2H), 7.59–7.61 (d, 1H, J = 6.9 Hz). 7.68–7.80 (m, 3H), 7.87–7.90 (m, 1H), 7.93–7.98 (t, 2H, J = 7.5, 9.0 Hz), 8.08–8.81 (m, 2H), 8.15–8.18 (d, 1H, J = 8.4 Hz). 13C NMR (CDCl3, 75 MHz): δ 23.82, 25.85, 26.73, 29.58, 32.02, 32.40, 33.49, 34.57, 41.71, 45.67, 49.97, 50.95, 60.21, 77.26, 113.61, 121.39, 122.15, 122.83, 123.47, 125.00, 128.44, 128.79, 128.92, 130.12, 131.45, 131.74, 135.65, 139.30, 142.84, 146.19, 150.21, 150.242, 153.39, 170.42, 195.61, 208.12. Mass: m/z 789 (M+). Anal. calculated for C49H47N3O7: C, 74.50%; H, 6.00%; N, 5.32%; Found: C, 74.62%; H, 6.11%; N, 5.41%.

2.3 Computational details

The input structures are drawn using Gaussview-5.0. [28] All the DFT computational calculations are performed using Gaussian 09 package [29]. In this work, the geometrical optimization of the molecule has been done using B3LYP/6-311g(d,p) level [26,27]. The frequency analysis is done on the optimized geometries and the results reveal that all the obtained frequencies are real which correspond to their ground state. Chem Craft software is used to portray the images of optimized geometries and the frontier molecular orbitals [30]. Using AutoDock Vina software, molecular docking analysis has been performed where DFT optimized structures have been used [31]. The three-dimensional structure of the protein is extracted from protein data bank. The PDB id for the protein is 6LU7 [32]. During docking process, a grid box with the sizes 60, 60, and 60 along the X-, Y-, and Z-axes is used as reported earlier [33,34]. The flow chart of the cycloaddition process has been described in

3 Results and discussion

3.1 Chemistry

The highly functionalized dipolarophiles, O-acryloylacridinediones 5a–b were derived from dimedone 1 in three good yielding steps [35] as shown in Scheme 1. Primarily, the reaction of dimedone 1 and aromatic aldehyde 2 in methanol afforded 4-hydroxyphenyl tetraketone 3 which was cyclized with 4-aminophenol in acetic acid to give the acridinediones 4a–b. The O-acylation of 4 with acryloyl chloride in CH2Cl2 in the presence of Et3N at 0°C to room temperature afforded O-acryloyl acridinediones 5a–b in good yields. The structure of the compounds was fully characterized by NMR spectroscopic data. In the 1H NMR spectrum of compound 5a, the two doublets at δ 6.10 and δ 6.66 were assigned to Ha and Hb of allyl –CH2 protons and a doublet of doublets at δ 6.33 to Hc proton. The 13C NMR spectrum of compound 5a showed a signal at δ 133.6 ppm due to the allyl –CH2, while the ester carbonyl group resonated at δ 163.95 ppm. The gem-dimethyl carbons resonated at δ 26.77 and δ 29.74 ppm and two methylene carbons appeared at δ 41.82 and δ 50.21 ppm.

Scheme 1 Synthesis of O-acryloylacridinedione dipolarophiles, 5a–b.
Scheme 1

Synthesis of O-acryloylacridinedione dipolarophiles, 5a–b.

With the acridinedione dipolarophiles in hand, to start with the three-component cycloaddition reaction, initially in order to optimize the reaction conditions, a representative reaction was carried out involving isatin 6, thiazolidine-4-carboxylc acid 7, and O-acryloyl acridinedione 5a with various solvent system such as methanol, 1,4-dioxane, acetonitrile, toluene, and tetrahydrofuran (Table 1). The reaction of isatin 6, thiazolidine-4-carboxylc acid 7 via a decarboxylative pathway furnished the 1,3-dipole component which in turn added regioselectivity to 5a. Thus, a mixture of 5a, 6, and 7 in 5 mL of CH3CN was refluxed for 8 h. After all starting materials had completely disappeared as indicated by TLC analysis, the crude product was purified by column chromatography and it was observed that among these solvents, the reaction in CH3CN gave the best yield of the product 8a (89%) than the other solvents. Since the main goal of organic synthesis is to develop a new synthetic strategy using green solvents, we performed the same reaction in an ionic liquid, [Bmim]Br and expected, a quantitative yield of 8a (92%) in [Bmim]Br was observed in a significantly shorter reaction time (5 h) (Scheme 2, Table 1). Subsequently, all other reactions were executed with the ionic liquid. It is pertinent to note that ionic liquids are eco-friendly green solvents because of their lower vapor pressure, good solvating capacity, high thermal and chemical stability, good solvating ability, non-coordinating nature, and easy recyclability which make them a good choice for various chemical reactions. In addition, ionic liquids have attracted tremendous attention in recent years due to their identification and tunable properties as green solvents, catalysts, and reagents. It is important to note that ionic liquids act as both catalysts and solvents in various synthetic transformations.

Table 1

Solvent optimization of mono-spirocycloadduct, 8a

Entry Solvents Time (h) Yield (%)
1 Methanol 12 47
2 1,4-Dioxane 18 12
3 Acetonitrile 8 89
4 Toluene 16 —
5 THF 12 34
6 [Bmim]Br 5 92
Scheme 2 Synthesis of spirooxindolothiopyrrolizidines/indolizidines, 8–10.
Scheme 2

Synthesis of spirooxindolothiopyrrolizidines/indolizidines, 8–10.

The structure and the regiochemistry of the cycloadducts were unambiguously established by their spectroscopic analysis. The 1H NMR spectrum of compound 8a showed a multiplet in the range δ 4.34–4.38 for Hb proton. The Ha proton was observed as a doublet of doublets at δ 3.97–4.03 (J = 6.6, 6.9 Hz). If another isomer was formed, one would expect a multiplet instead of a doublet of doublet. The Hc and Hd protons appeared as a multiplet in the range δ 2.32–2.44 and δ 2.54–2.62, respectively. The methylene proton flanked between the nitrogen and sulfur atom appeared as two doublets at δ 3.48 and 3.90. The –NH proton of the oxindole ring resonated at δ 9.05 ppm as a singlet. The gem-dimethyl proton showed two singlets at δ 0.77 and 0.92 ppm for acridinedione moiety. The 13C NMR spectrum of 8a exhibited a peak at δ 180.44 ppm due to acridinedione carbonyl carbon. The two peaks at δ 168.44 and 196.08 ppm were due to oxindole and ester carbonyl carbons. A peak at δ 73.97 ppm was accounted for the spiro carbon of oxindole moiety. The DEPT 135 spectrum showed peaks at δ 33.46, 38.17, 41.72, 50.13, and 55.00 ppm in negative region for the five methylene carbons present in the cycloadducts (Figure 2).

Figure 2 Selected 1H and 13C NMR chemical shifts of 8a.
Figure 2

Selected 1H and 13C NMR chemical shifts of 8a.

We extended the same methodology for the synthesis of a novel mono spirooxindoloindolizidines 10a–b. The non-stabilized azomethine ylide generated in situ from isatin 6 with pipecolinic acid 9, underwent cycloaddition with O-acryloyl acridinedione 5a–b in ionic liquids, [Bmim]Br condition to afford mono spirooxindoloindolizidines 10a–b in good yields (Scheme 2). No trace of the other possible regioisomer was observed even after prolonged reaction time. The structure and regiochemistry of the products 10a–b were established by IR, 1H and 13C NMR spectroscopy analysis. The 1H NMR spectrum of compound 10b exhibited a multiplet in the range of δ 3.23–3.29 for Hb proton. The doublet of doublet appeared at δ 3.70 due to Ha proton confirmed the regio chemistry of the cycloaddition. The Hc and Hd protons resonated at δ 2.30–2.53 as a multiplet. The –NH proton of the oxindole ring resonated at δ 7.78 as a singlet. The gem-dimethyl proton showed two singlets at δ 0.77 and 0.94 for acridinedione moiety. In the 13C NMR spectrum of cycloadduct 10b, the ester and oxindole carbonyl carbon were resonated at 195.84 and 170.10 ppm, respectively. The acridinedione carbonyl carbon appeared at 180.26 ppm and the spiro quaternary carbon of oxindole ring appeared at 72.40 ppm. In DEPT 135 studies confirmed the presence of seven methylene carbons in cycloadduct which appeared at 23.72, 25.69, 31.88, 34.21, 41.89, 45.48, and 49.97 ppm.

The utility of acridinedione dipolarophiles 5a–b in the preparation of diverse spiroheterocyclic hybrids were further explored by executing the cycloaddition process with different diketone, acenaphthenequinone 11. Thus, an equimolar mixture of acenapthequinone 11, thiazolidine-4-carboxylc acid 7/pipecolinic acid 9, and O-acryloylacridinedione 5a–b refluxed in [Bmim]Br at 100°C resulted in the formation of spiroacenapthenothiopyrrolizidines 12a–b/indolizidines 13a–b in good yield (Scheme 3, Table 2). The formation of the products was confirmed by the spectroscopic analysis.

Scheme 3 Synthesis of acenaphthenopyrrolizidines/indolizidines, 12–13.
Scheme 3

Synthesis of acenaphthenopyrrolizidines/indolizidines, 12–13.

A plausible reaction pathway for the formation of the spirohybrid heterocycles 8–10 and 12–13 is described in Scheme 4 considering a representative case 8a. Initially, the condensation reaction of isatin 6 and thiazolidine-4-carboxylic acid 7 afforded the iminium ion intermediate 14 by dehydration. The spirooxazolidinone 15 derived from 14 afforded the reactive azomethine ylide 16 by decarboxylation. The cycloaddition reaction of the 1,3-dipole component 16 and the alkene 5a, may occur either via route A or route B. However, the exclusive formation of spirooxindolothiopyrrolizidines 8a revealed that route A is favored than route B. In route A, the amide carbonyl group of the 1,3-dipole 16 having secondary orbital interaction (SOI) [36] with the carbonyl group of dipolarophile 5a with ylide 16, whereas in route B such kind of SOI was ruled out because the carbonyl group of dipole 16 is far away from the carbonyl group of dipolarophile 5a. In addition, the regioselectivity product 8a was observed and other possible regioisomer 17 was not formed since the electron rich dipole 16 preferentially attacks the electron deficient β-carbon of 5a affording 8a. The resulting cycloadduct obtained possesses three sterogenic carbons that have a spiro carbon via the generation of one C–N and two C–C in a one-pot reaction sequence.

Scheme 4 Persuasive mechanism for the synthesis of spiroheterocyclic hybrids.
Scheme 4

Persuasive mechanism for the synthesis of spiroheterocyclic hybrids.

3.2 Geometrical analysis

The optimized geometry of the molecules is given in Figure 3. From the figure, it is clear that the molecules are not planar and are twisted. The molecules are twisted due to the presence of C–C single bonds between moieties. All the molecules are twisted by an angle of ∼154°. The bond length of C═O in all the molecules is observed to be at around 1.91 Å. In all the molecules, the oxygen flanked between the carboxyl group and the benzene is acting as a conjugation stopper. In molecules 8a, 8b, 10a, and 10b, the hydrogen of –NH group can be easily abstracted. For instance, in these molecules the –NH bonds are having a length of 1.01 Å while the usual –NH bond is 1.00 Å. Thus, due to this –NH elongation in these molecules the hydrogen atoms can be abstracted.

Figure 3 Optimized geometry of the molecules.
Figure 3

Optimized geometry of the molecules.

3.2.1 Frontier molecular orbitals analysis

Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the molecules are given in Figure 4. It can be seen that the HOMO of the molecules is localized on the hexahydro acridine dione moiety. The LUMO of 8a and 10a is localized on the hexahydro acridine dione and the benzoic acid moieties, whereas on substitution of NO2 in the 8b and 10b molecules the LUMO gets localized on phenyl and hexahydro acridine dione moieties. In the case of 12a, 12b, 13a, and 13b molecules the LUMO is localized on acenaphthylenone moiety. The HOMO–LUMO energy gap is depicted in Figure 5. The HOMO–LUMO gap is greatest in 10a (4.13 eV) and lowest in 12b (3.13 eV). Thus, 10a molecule is the most stable and 12b molecule is expected to be highly active with a low HOMO–LUMO gap among all the molecules. The HOMO–LUMO gap values are in the range of 3.13–4.13 eV.

Figure 4 Frontier molecular orbitals of the molecules.
Figure 4

Frontier molecular orbitals of the molecules.

Figure 5 HOMO–LUMO energy gap of the molecules.
Figure 5

HOMO–LUMO energy gap of the molecules.

Table 2

Cycloaddition of ylides generated from di ketones and secondary amino acids with the dipolarophiles, 5a–b

Entry Dipolarophile Diketone Sec-amino acid Products Time (h) Yield (%)a
1 5a 6 7 8a 5 84
2 5b 6 7 8b 4.5 87
3 5a 6 9 10a 4 79
4 5b 6 9 10b 3.5 81
5 5a 11 7 12a 4 80
6 5b 11 7 12b 3.5 83
7 5a 11 9 13a 5 85
8 5b 11 9 13b 4.5 86

aIsolated product after column chromatography.

3.2.2 Molecular docking

Drug designing industry largely depends on computer-aided tools in predicting the activity of drugs at molecular level. One such important tool is molecular docking analysis which is used to find out the binding modes of the drugs, inhibitors, ligands, and metal complexes toward the protein [37]. Therefore, molecular docking analysis in combination with density functional theory calculations is carried out. Results of molecular docking reveal that the 8b molecule shows better binding ability than the other molecules. 8b has the highest binding energy with −10.4 kcal·mol−1. The most favorable docking pose of ligand–protein for all molecules is given in Figure 6. The decreasing order of binding energies in the synthesized molecules is 8b > 12a > 12b > 10b, 13a > 8a > 10a, 13b. The representation of the interactions of the molecules with amino acids of the protein for all is given in Figure 7. The results obtained from Figures 6 and 7 are discussed below. The binding pocket of 8a consists of the following resides: Thr 199, Asn 238, Thr 196, Asp 197, Ala 194, Val 171, Thr 135, Asn 133, Thr 169, Agr131, Lys 137, Tyr 239, Leu 286, Leu 287, Met276, Gly 275, Leu 271, Leu 272, and Tyr 237. The ligand 8a has one π-donor hydrogen bond with Asn 133, two π-sigma interactions with Leu 287 and Val 171 and one π-alkyl interaction with Ala 194. In 8b Leu 286 has three interactions: π-sigma interaction and two π-alkyl interactions. Apart from this 8b has a π-donor hydrogen bond with Leu 287 and a π-alkyl interaction with Ala 285. Also, 8b has a conventional hydrogen bond with Lys 137 with a distance of 2.00 Å. For 10a conventional hydrogen bonds are observed with Arg 131 (2.80 Å) and Asn (2.09 Å), two π-alkyl interactions with Leu 286 and a π-alkyl interaction with Met 276. 10b has a conventional hydrogen bond with Trp 207 having a distance of 2.20 Å and three π-alkyl interactions with Leu 286. The molecule 12a has one conventional hydrogen bond (Tyr 239) with a distance of 2.13 Å, one π-sigma interaction (Val 171) and five π-alkyl interactions (Asp 197, Ala 194, Leu 286, Met 276, and Leu 287). 12b molecule has three interactions with Leu 286 (one π-sigma interaction and two π-alkyl interactions). Apart from this 12b has a conventional hydrogen bond with Thr 199 having a bond distance of 3.06 Å. For 13a molecule one π-anion interaction with Glu 288, one π-sigma interaction with Leu 286 and three π-alkyl interactions with Lys 137, Leu 286, and Leu 287 is observed. 13a also has two conventional hydrogen bonds with Lys 137 (2.66 Å) and Tyr 239 (2.62 Å). The 13b molecule has two π–π T-shaped interactions with Tyr 237, two π-alkyl interactions with Leu 286, one π-cation interaction with Lys 137 and one conventional hydrogen bond with Lys 137 (2.62 Å). Thus, all the ligands are stabilized by hydrogen bonding, π–π interactions and electrostatic interactions. Hence, all these molecules are promising inhibitors for COVID-19 drug discovery and further experimental studies have to be done in order to prove their utility.

Figure 6 Molecular docking studies on the best possible binding position of molecules in the protein.
Figure 6

Molecular docking studies on the best possible binding position of molecules in the protein.

Figure 7 Schematic representation of interaction of spirocompounds with the protein.
Figure 7

Schematic representation of interaction of spirocompounds with the protein.

4 Conclusion

A series of structurally intriguing new class of acridinedione embedded spirooxindolothiazolidine/indolizidine and spiroacenapthenothiazolidine/indolizidine has been synthesized in quantitative yields employing ionic liquid supported eco-friendly green protocol. The cycloaddition protocol was investigated under various solvent systems and observed that ionic liquids are better yield than other organic solvents. The cycloaddition protocol generated three stereogenic carbons, out of three one is spiro carbon via the formation of C–N and two C–C bonds in single synthetic transformation. These cycloadducts were unambiguously assigned by spectroscopic analysis. Geometrical parameters of the synthesized compounds were investigated using the B3LYP/6-311g(d,p) level of theory. Molecular simulation was performed to understand the binding affinity of spiro compounds with protein. The molecules are stabilized by hydrogen bonding interactions along with other non-covalent interactions and results reveal that spiro compound 8b binds to the protein more readily than the other compounds. As spiroheterocycles are prime compounds with unique structural features, the current methodology described in this study can be adopted for the synthesis of similar spiroheterocycles with diverse substitutions and can be evaluated multifarious biological assays.

  1. Funding information: The project was funded by Researchers Supporting Project Number (RSP2023R143), King Saud University, Riyadh, Saudi Arabia.

  2. Author contributions: Rajesh Raju, Raghavachary Raghunathan, and Natarajan Arumugam: conceptualization, investigation, supervision, formal analysis, methodology, validation, writing – original draft, visualization; Raju Suresh Kumar: methodology, validation, writing – review and editing; Abdulrahman I. Almansour: project administration, visualization, writing – review and editing; P.A. Vivekanand: writing – review and editing; Cheriyan Ebenezer and Rajadurai Vijay Solomon: validation, writing – review and editing. Karthikeyan Perumal: investigation, formal analysis, methodology.

  3. Conflict of interest: The authors state no conflict of interest.

  4. Data availability statement: All materials for this study are presented in this article and available on request to the corresponding author.

Appendix

A1 Selected 1H and 13C NMR spectra of the spirocompounds

Figure A1 1H NMR spectrum of compound 8a.
Figure A1

1H NMR spectrum of compound 8a.

Figure A2 1H NMR expansion spectrum of compound 8a.
Figure A2

1H NMR expansion spectrum of compound 8a.

Figure A3 13C NMR spectrum of compound 8a.
Figure A3

13C NMR spectrum of compound 8a.

Figure A4 DEPT 135 NMR spectrum of compound 8a.
Figure A4

DEPT 135 NMR spectrum of compound 8a.

Figure A5 1H NMR spectrum of compound 13a.
Figure A5

1H NMR spectrum of compound 13a.

Figure A6 13C NMR spectrum of compound 13a.
Figure A6

13C NMR spectrum of compound 13a.

Figure A7 DEPT 135 NMR spectrum of compound 13a.
Figure A7

DEPT 135 NMR spectrum of compound 13a.

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Received: 2023-03-01
Revised: 2023-06-07
Accepted: 2023-06-18
Published Online: 2023-07-13

© 2023 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Research Articles
  2. Value-added utilization of coal fly ash and recycled polyvinyl chloride in door or window sub-frame composites
  3. High removal efficiency of volatile phenol from coking wastewater using coal gasification slag via optimized adsorption and multi-grade batch process
  4. Evolution of surface morphology and properties of diamond films by hydrogen plasma etching
  5. Removal efficiency of dibenzofuran using CuZn-zeolitic imidazole frameworks as a catalyst and adsorbent
  6. Rapid and efficient microwave-assisted extraction of Caesalpinia sappan Linn. heartwood and subsequent synthesis of gold nanoparticles
  7. The catalytic characteristics of 2-methylnaphthalene acylation with AlCl3 immobilized on Hβ as Lewis acid catalyst
  8. Biodegradation of synthetic PVP biofilms using natural materials and nanoparticles
  9. Rutin-loaded selenium nanoparticles modulated the redox status, inflammatory, and apoptotic pathways associated with pentylenetetrazole-induced epilepsy in mice
  10. Optimization of apigenin nanoparticles prepared by planetary ball milling: In vitro and in vivo studies
  11. Synthesis and characterization of silver nanoparticles using Origanum onites leaves: Cytotoxic, apoptotic, and necrotic effects on Capan-1, L929, and Caco-2 cell lines
  12. Exergy analysis of a conceptual CO2 capture process with an amine-based DES
  13. Construction of fluorescence system of felodipine–tetracyanovinyl–2,2′-bipyridine complex
  14. Excellent photocatalytic degradation of rhodamine B over Bi2O3 supported on Zn-MOF nanocomposites under visible light
  15. Optimization-based control strategy for a large-scale polyhydroxyalkanoates production in a fed-batch bioreactor using a coupled PDE–ODE system
  16. Effectiveness of pH and amount of Artemia urumiana extract on physical, chemical, and biological attributes of UV-fabricated biogold nanoparticles
  17. Geranium leaf-mediated synthesis of silver nanoparticles and their transcriptomic effects on Candida albicans
  18. Synthesis, characterization, anticancer, anti-inflammatory activities, and docking studies of 3,5-disubstituted thiadiazine-2-thiones
  19. Synthesis and stability of phospholipid-encapsulated nano-selenium
  20. Putative anti-proliferative effect of Indian mustard (Brassica juncea) seed and its nano-formulation
  21. Enrichment of low-grade phosphorites by the selective leaching method
  22. Electrochemical analysis of the dissolution of gold in a copper–ethylenediamine–thiosulfate system
  23. Characterisation of carbonate lake sediments as a potential filler for polymer composites
  24. Evaluation of nano-selenium biofortification characteristics of alfalfa (Medicago sativa L.)
  25. Quality of oil extracted by cold press from Nigella sativa seeds incorporated with rosemary extracts and pretreated by microwaves
  26. Heteropolyacid-loaded MOF-derived mesoporous zirconia catalyst for chemical degradation of rhodamine B
  27. Recovery of critical metals from carbonatite-type mineral wastes: Geochemical modeling investigation of (bio)hydrometallurgical leaching of REEs
  28. Photocatalytic properties of ZnFe-mixed oxides synthesized via a simple route for water remediation
  29. Attenuation of di(2-ethylhexyl)phthalate-induced hepatic and renal toxicity by naringin nanoparticles in a rat model
  30. Novel in situ synthesis of quaternary core–shell metallic sulfide nanocomposites for degradation of organic dyes and hydrogen production
  31. Microfluidic steam-based synthesis of luminescent carbon quantum dots as sensing probes for nitrite detection
  32. Transformation of eggshell waste to egg white protein solution, calcium chloride dihydrate, and eggshell membrane powder
  33. Preparation of Zr-MOFs for the adsorption of doxycycline hydrochloride from wastewater
  34. Green nanoarchitectonics of the silver nanocrystal potential for treating malaria and their cytotoxic effects on the kidney Vero cell line
  35. Carbon emissions analysis of producing modified asphalt with natural asphalt
  36. An efficient and green synthesis of 2-phenylquinazolin-4(3H)-ones via t-BuONa-mediated oxidative condensation of 2-aminobenzamides and benzyl alcohols under solvent- and transition metal-free conditions
  37. Chitosan nanoparticles loaded with mesosulfuron methyl and mesosulfuron methyl + florasulam + MCPA isooctyl to manage weeds of wheat (Triticum aestivum L.)
  38. Synergism between lignite and high-sulfur petroleum coke in CO2 gasification
  39. Facile aqueous synthesis of ZnCuInS/ZnS–ZnS QDs with enhanced photoluminescence lifetime for selective detection of Cu(ii) ions
  40. Rapid synthesis of copper nanoparticles using Nepeta cataria leaves: An eco-friendly management of disease-causing vectors and bacterial pathogens
  41. Study on the photoelectrocatalytic activity of reduced TiO2 nanotube films for removal of methyl orange
  42. Development of a fuzzy logic model for the prediction of spark-ignition engine performance and emission for gasoline–ethanol blends
  43. Micro-impact-induced mechano-chemical synthesis of organic precursors from FeC/FeN and carbonates/nitrates in water and its extension to nucleobases
  44. Green synthesis of strontium-doped tin dioxide (SrSnO2) nanoparticles using the Mahonia bealei leaf extract and evaluation of their anticancer and antimicrobial activities
  45. A study on the larvicidal and adulticidal potential of Cladostepus spongiosus macroalgae and green-fabricated silver nanoparticles against mosquito vectors
  46. Catalysts based on nickel salt heteropolytungstates for selective oxidation of diphenyl sulfide
  47. Powerful antibacterial nanocomposites from Corallina officinalis-mediated nanometals and chitosan nanoparticles against fish-borne pathogens
  48. Removal behavior of Zn and alkalis from blast furnace dust in pre-reduction sinter process
  49. Environmentally friendly synthesis and computational studies of novel class of acridinedione integrated spirothiopyrrolizidines/indolizidines
  50. The mechanisms of inhibition and lubrication of clean fracturing flowback fluids in water-based drilling fluids
  51. Adsorption/desorption performance of cellulose membrane for Pb(ii)
  52. A one-pot, multicomponent tandem synthesis of fused polycyclic pyrrolo[3,2-c]quinolinone/pyrrolizino[2,3-c]quinolinone hybrid heterocycles via environmentally benign solid state melt reaction
  53. Green synthesis of silver nanoparticles using durian rind extract and optical characteristics of surface plasmon resonance-based optical sensor for the detection of hydrogen peroxide
  54. Electrochemical analysis of copper-EDTA-ammonia-gold thiosulfate dissolution system
  55. Characterization of bio-oil production by microwave pyrolysis from cashew nut shells and Cassia fistula pods
  56. Green synthesis methods and characterization of bacterial cellulose/silver nanoparticle composites
  57. Photocatalytic research performance of zinc oxide/graphite phase carbon nitride catalyst and its application in environment
  58. Effect of phytogenic iron nanoparticles on the bio-fortification of wheat varieties
  59. In vitro anti-cancer and antimicrobial effects of manganese oxide nanoparticles synthesized using the Glycyrrhiza uralensis leaf extract on breast cancer cell lines
  60. Preparation of Pd/Ce(F)-MCM-48 catalysts and their catalytic performance of n-heptane isomerization
  61. Green “one-pot” fluorescent bis-indolizine synthesis with whole-cell plant biocatalysis
  62. Silica-titania mesoporous silicas of MCM-41 type as effective catalysts and photocatalysts for selective oxidation of diphenyl sulfide by H2O2
  63. Biosynthesis of zinc oxide nanoparticles from molted feathers of Pavo cristatus and their antibiofilm and anticancer activities
  64. Clean preparation of rutile from Ti-containing mixed molten slag by CO2 oxidation
  65. Synthesis and characterization of Pluronic F-127-coated titanium dioxide nanoparticles synthesized from extracts of Atractylodes macrocephala leaf for antioxidant, antimicrobial, and anticancer properties
  66. Effect of pretreatment with alkali on the anaerobic digestion characteristics of kitchen waste and analysis of microbial diversity
  67. Ameliorated antimicrobial, antioxidant, and anticancer properties by Plectranthus vettiveroides root extract-mediated green synthesis of chitosan nanoparticles
  68. Microwave-accelerated pretreatment technique in green extraction of oil and bioactive compounds from camelina seeds: Effectiveness and characterization
  69. Studies on the extraction performance of phorate by aptamer-functionalized magnetic nanoparticles in plasma samples
  70. Investigation of structural properties and antibacterial activity of AgO nanoparticle extract from Solanum nigrum/Mentha leaf extracts by green synthesis method
  71. Green fabrication of chitosan from marine crustaceans and mushroom waste: Toward sustainable resource utilization
  72. Synthesis, characterization, and evaluation of nanoparticles of clodinofop propargyl and fenoxaprop-P-ethyl on weed control, growth, and yield of wheat (Triticum aestivum L.)
  73. The enhanced adsorption properties of phosphorus from aqueous solutions using lanthanum modified synthetic zeolites
  74. Separation of graphene oxides of different sizes by multi-layer dialysis and anti-friction and lubrication performance
  75. Visible-light-assisted base-catalyzed, one-pot synthesis of highly functionalized cinnolines
  76. The experimental study on the air oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid with Co–Mn–Br system
  77. Highly efficient removal of tetracycline and methyl violet 2B from aqueous solution using the bimetallic FeZn-ZIFs catalyst
  78. A thermo-tolerant cellulase enzyme produced by Bacillus amyloliquefaciens M7, an insight into synthesis, optimization, characterization, and bio-polishing activity
  79. Exploration of ketone derivatives of succinimide for their antidiabetic potential: In vitro and in vivo approaches
  80. Ultrasound-assisted green synthesis and in silico study of 6-(4-(butylamino)-6-(diethylamino)-1,3,5-triazin-2-yl)oxypyridazine derivatives
  81. A study of the anticancer potential of Pluronic F-127 encapsulated Fe2O3 nanoparticles derived from Berberis vulgaris extract
  82. Biogenic synthesis of silver nanoparticles using Consolida orientalis flowers: Identification, catalytic degradation, and biological effect
  83. Initial assessment of the presence of plastic waste in some coastal mangrove forests in Vietnam
  84. Adsorption synergy electrocatalytic degradation of phenol by active oxygen-containing species generated in Co-coal based cathode and graphite anode
  85. Antibacterial, antifungal, antioxidant, and cytotoxicity activities of the aqueous extract of Syzygium aromaticum-mediated synthesized novel silver nanoparticles
  86. Synthesis of a silica matrix with ZnO nanoparticles for the fabrication of a recyclable photodegradation system to eliminate methylene blue dye
  87. Natural polymer fillers instead of dye and pigments: Pumice and scoria in PDMS fluid and elastomer composites
  88. Study on the preparation of glycerylphosphorylcholine by transesterification under supported sodium methoxide
  89. Wireless network handheld terminal-based green ecological sustainable design evaluation system: Improved data communication and reduced packet loss rate
  90. The optimization of hydrogel strength from cassava starch using oxidized sucrose as a crosslinking agent
  91. Green synthesis of silver nanoparticles using Saccharum officinarum leaf extract for antiviral paint
  92. Study on the reliability of nano-silver-coated tin solder joints for flip chips
  93. Environmentally sustainable analytical quality by design aided RP-HPLC method for the estimation of brilliant blue in commercial food samples employing a green-ultrasound-assisted extraction technique
  94. Anticancer and antimicrobial potential of zinc/sodium alginate/polyethylene glycol/d-pinitol nanocomposites against osteosarcoma MG-63 cells
  95. Nanoporous carbon@CoFe2O4 nanocomposite as a green absorbent for the adsorptive removal of Hg(ii) from aqueous solutions
  96. Characterization of silver sulfide nanoparticles from actinobacterial strain (M10A62) and its toxicity against lepidopteran and dipterans insect species
  97. Phyto-fabrication and characterization of silver nanoparticles using Withania somnifera: Investigating antioxidant potential
  98. Effect of e-waste nanofillers on the mechanical, thermal, and wear properties of epoxy-blend sisal woven fiber-reinforced composites
  99. Magnesium nanohydroxide (2D brucite) as a host matrix for thymol and carvacrol: Synthesis, characterization, and inhibition of foodborne pathogens
  100. Synergistic inhibitive effect of a hybrid zinc oxide-benzalkonium chloride composite on the corrosion of carbon steel in a sulfuric acidic solution
  101. Review Articles
  102. Role and the importance of green approach in biosynthesis of nanopropolis and effectiveness of propolis in the treatment of COVID-19 pandemic
  103. Gum tragacanth-mediated synthesis of metal nanoparticles, characterization, and their applications as a bactericide, catalyst, antioxidant, and peroxidase mimic
  104. Green-processed nano-biocomposite (ZnO–TiO2): Potential candidates for biomedical applications
  105. Reaction mechanisms in microwave-assisted lignin depolymerisation in hydrogen-donating solvents
  106. Recent progress on non-noble metal catalysts for the deoxydehydration of biomass-derived oxygenates
  107. Rapid Communication
  108. Phosphorus removal by iron–carbon microelectrolysis: A new way to achieve phosphorus recovery
  109. Special Issue: Biomolecules-derived synthesis of nanomaterials for environmental and biological applications (Guest Editors: Arpita Roy and Fernanda Maria Policarpo Tonelli)
  110. Biomolecules-derived synthesis of nanomaterials for environmental and biological applications
  111. Nano-encapsulated tanshinone IIA in PLGA-PEG-COOH inhibits apoptosis and inflammation in cerebral ischemia/reperfusion injury
  112. Green fabrication of silver nanoparticles using Melia azedarach ripened fruit extract, their characterization, and biological properties
  113. Green-synthesized nanoparticles and their therapeutic applications: A review
  114. Antioxidant, antibacterial, and cytotoxicity potential of synthesized silver nanoparticles from the Cassia alata leaf aqueous extract
  115. Green synthesis of silver nanoparticles using Callisia fragrans leaf extract and its anticancer activity against MCF-7, HepG2, KB, LU-1, and MKN-7 cell lines
  116. Algae-based green AgNPs, AuNPs, and FeNPs as potential nanoremediators
  117. Green synthesis of Kickxia elatine-induced silver nanoparticles and their role as anti-acetylcholinesterase in the treatment of Alzheimer’s disease
  118. Phytocrystallization of silver nanoparticles using Cassia alata flower extract for effective control of fungal skin pathogens
  119. Antibacterial wound dressing with hydrogel from chitosan and polyvinyl alcohol from the red cabbage extract loaded with silver nanoparticles
  120. Leveraging of mycogenic copper oxide nanostructures for disease management of Alternaria blight of Brassica juncea
  121. Nanoscale molecular reactions in microbiological medicines in modern medical applications
  122. Synthesis and characterization of ZnO/β-cyclodextrin/nicotinic acid nanocomposite and its biological and environmental application
  123. Green synthesis of silver nanoparticles via Taxus wallichiana Zucc. plant-derived Taxol: Novel utilization as anticancer, antioxidation, anti-inflammation, and antiurolithic potential
  124. Recyclability and catalytic characteristics of copper oxide nanoparticles derived from bougainvillea plant flower extract for biomedical application
  125. Phytofabrication, characterization, and evaluation of novel bioinspired selenium–iron (Se–Fe) nanocomposites using Allium sativum extract for bio-potential applications
  126. Erratum
  127. Erratum to “Synthesis, characterization, and evaluation of nanoparticles of clodinofop propargyl and fenoxaprop-P-ethyl on weed control, growth, and yield of wheat (Triticum aestivum L.)”
https://doi.org/10.1515/gps-2023-0036
Keywords for this article
spirooxindolo/acenathenothiopyrrolidines; spirooxindolo/acenathenoindolizidines; acridinedione; ecofriendly green protocol; 1,3-dipolar cycloaddition
Creative Commons
BY 4.0

Articles in the same Issue

  1. Research Articles
  2. Value-added utilization of coal fly ash and recycled polyvinyl chloride in door or window sub-frame composites
  3. High removal efficiency of volatile phenol from coking wastewater using coal gasification slag via optimized adsorption and multi-grade batch process
  4. Evolution of surface morphology and properties of diamond films by hydrogen plasma etching
  5. Removal efficiency of dibenzofuran using CuZn-zeolitic imidazole frameworks as a catalyst and adsorbent
  6. Rapid and efficient microwave-assisted extraction of Caesalpinia sappan Linn. heartwood and subsequent synthesis of gold nanoparticles
  7. The catalytic characteristics of 2-methylnaphthalene acylation with AlCl3 immobilized on Hβ as Lewis acid catalyst
  8. Biodegradation of synthetic PVP biofilms using natural materials and nanoparticles
  9. Rutin-loaded selenium nanoparticles modulated the redox status, inflammatory, and apoptotic pathways associated with pentylenetetrazole-induced epilepsy in mice
  10. Optimization of apigenin nanoparticles prepared by planetary ball milling: In vitro and in vivo studies
  11. Synthesis and characterization of silver nanoparticles using Origanum onites leaves: Cytotoxic, apoptotic, and necrotic effects on Capan-1, L929, and Caco-2 cell lines
  12. Exergy analysis of a conceptual CO2 capture process with an amine-based DES
  13. Construction of fluorescence system of felodipine–tetracyanovinyl–2,2′-bipyridine complex
  14. Excellent photocatalytic degradation of rhodamine B over Bi2O3 supported on Zn-MOF nanocomposites under visible light
  15. Optimization-based control strategy for a large-scale polyhydroxyalkanoates production in a fed-batch bioreactor using a coupled PDE–ODE system
  16. Effectiveness of pH and amount of Artemia urumiana extract on physical, chemical, and biological attributes of UV-fabricated biogold nanoparticles
  17. Geranium leaf-mediated synthesis of silver nanoparticles and their transcriptomic effects on Candida albicans
  18. Synthesis, characterization, anticancer, anti-inflammatory activities, and docking studies of 3,5-disubstituted thiadiazine-2-thiones
  19. Synthesis and stability of phospholipid-encapsulated nano-selenium
  20. Putative anti-proliferative effect of Indian mustard (Brassica juncea) seed and its nano-formulation
  21. Enrichment of low-grade phosphorites by the selective leaching method
  22. Electrochemical analysis of the dissolution of gold in a copper–ethylenediamine–thiosulfate system
  23. Characterisation of carbonate lake sediments as a potential filler for polymer composites
  24. Evaluation of nano-selenium biofortification characteristics of alfalfa (Medicago sativa L.)
  25. Quality of oil extracted by cold press from Nigella sativa seeds incorporated with rosemary extracts and pretreated by microwaves
  26. Heteropolyacid-loaded MOF-derived mesoporous zirconia catalyst for chemical degradation of rhodamine B
  27. Recovery of critical metals from carbonatite-type mineral wastes: Geochemical modeling investigation of (bio)hydrometallurgical leaching of REEs
  28. Photocatalytic properties of ZnFe-mixed oxides synthesized via a simple route for water remediation
  29. Attenuation of di(2-ethylhexyl)phthalate-induced hepatic and renal toxicity by naringin nanoparticles in a rat model
  30. Novel in situ synthesis of quaternary core–shell metallic sulfide nanocomposites for degradation of organic dyes and hydrogen production
  31. Microfluidic steam-based synthesis of luminescent carbon quantum dots as sensing probes for nitrite detection
  32. Transformation of eggshell waste to egg white protein solution, calcium chloride dihydrate, and eggshell membrane powder
  33. Preparation of Zr-MOFs for the adsorption of doxycycline hydrochloride from wastewater
  34. Green nanoarchitectonics of the silver nanocrystal potential for treating malaria and their cytotoxic effects on the kidney Vero cell line
  35. Carbon emissions analysis of producing modified asphalt with natural asphalt
  36. An efficient and green synthesis of 2-phenylquinazolin-4(3H)-ones via t-BuONa-mediated oxidative condensation of 2-aminobenzamides and benzyl alcohols under solvent- and transition metal-free conditions
  37. Chitosan nanoparticles loaded with mesosulfuron methyl and mesosulfuron methyl + florasulam + MCPA isooctyl to manage weeds of wheat (Triticum aestivum L.)
  38. Synergism between lignite and high-sulfur petroleum coke in CO2 gasification
  39. Facile aqueous synthesis of ZnCuInS/ZnS–ZnS QDs with enhanced photoluminescence lifetime for selective detection of Cu(ii) ions
  40. Rapid synthesis of copper nanoparticles using Nepeta cataria leaves: An eco-friendly management of disease-causing vectors and bacterial pathogens
  41. Study on the photoelectrocatalytic activity of reduced TiO2 nanotube films for removal of methyl orange
  42. Development of a fuzzy logic model for the prediction of spark-ignition engine performance and emission for gasoline–ethanol blends
  43. Micro-impact-induced mechano-chemical synthesis of organic precursors from FeC/FeN and carbonates/nitrates in water and its extension to nucleobases
  44. Green synthesis of strontium-doped tin dioxide (SrSnO2) nanoparticles using the Mahonia bealei leaf extract and evaluation of their anticancer and antimicrobial activities
  45. A study on the larvicidal and adulticidal potential of Cladostepus spongiosus macroalgae and green-fabricated silver nanoparticles against mosquito vectors
  46. Catalysts based on nickel salt heteropolytungstates for selective oxidation of diphenyl sulfide
  47. Powerful antibacterial nanocomposites from Corallina officinalis-mediated nanometals and chitosan nanoparticles against fish-borne pathogens
  48. Removal behavior of Zn and alkalis from blast furnace dust in pre-reduction sinter process
  49. Environmentally friendly synthesis and computational studies of novel class of acridinedione integrated spirothiopyrrolizidines/indolizidines
  50. The mechanisms of inhibition and lubrication of clean fracturing flowback fluids in water-based drilling fluids
  51. Adsorption/desorption performance of cellulose membrane for Pb(ii)
  52. A one-pot, multicomponent tandem synthesis of fused polycyclic pyrrolo[3,2-c]quinolinone/pyrrolizino[2,3-c]quinolinone hybrid heterocycles via environmentally benign solid state melt reaction
  53. Green synthesis of silver nanoparticles using durian rind extract and optical characteristics of surface plasmon resonance-based optical sensor for the detection of hydrogen peroxide
  54. Electrochemical analysis of copper-EDTA-ammonia-gold thiosulfate dissolution system
  55. Characterization of bio-oil production by microwave pyrolysis from cashew nut shells and Cassia fistula pods
  56. Green synthesis methods and characterization of bacterial cellulose/silver nanoparticle composites
  57. Photocatalytic research performance of zinc oxide/graphite phase carbon nitride catalyst and its application in environment
  58. Effect of phytogenic iron nanoparticles on the bio-fortification of wheat varieties
  59. In vitro anti-cancer and antimicrobial effects of manganese oxide nanoparticles synthesized using the Glycyrrhiza uralensis leaf extract on breast cancer cell lines
  60. Preparation of Pd/Ce(F)-MCM-48 catalysts and their catalytic performance of n-heptane isomerization
  61. Green “one-pot” fluorescent bis-indolizine synthesis with whole-cell plant biocatalysis
  62. Silica-titania mesoporous silicas of MCM-41 type as effective catalysts and photocatalysts for selective oxidation of diphenyl sulfide by H2O2
  63. Biosynthesis of zinc oxide nanoparticles from molted feathers of Pavo cristatus and their antibiofilm and anticancer activities
  64. Clean preparation of rutile from Ti-containing mixed molten slag by CO2 oxidation
  65. Synthesis and characterization of Pluronic F-127-coated titanium dioxide nanoparticles synthesized from extracts of Atractylodes macrocephala leaf for antioxidant, antimicrobial, and anticancer properties
  66. Effect of pretreatment with alkali on the anaerobic digestion characteristics of kitchen waste and analysis of microbial diversity
  67. Ameliorated antimicrobial, antioxidant, and anticancer properties by Plectranthus vettiveroides root extract-mediated green synthesis of chitosan nanoparticles
  68. Microwave-accelerated pretreatment technique in green extraction of oil and bioactive compounds from camelina seeds: Effectiveness and characterization
  69. Studies on the extraction performance of phorate by aptamer-functionalized magnetic nanoparticles in plasma samples
  70. Investigation of structural properties and antibacterial activity of AgO nanoparticle extract from Solanum nigrum/Mentha leaf extracts by green synthesis method
  71. Green fabrication of chitosan from marine crustaceans and mushroom waste: Toward sustainable resource utilization
  72. Synthesis, characterization, and evaluation of nanoparticles of clodinofop propargyl and fenoxaprop-P-ethyl on weed control, growth, and yield of wheat (Triticum aestivum L.)
  73. The enhanced adsorption properties of phosphorus from aqueous solutions using lanthanum modified synthetic zeolites
  74. Separation of graphene oxides of different sizes by multi-layer dialysis and anti-friction and lubrication performance
  75. Visible-light-assisted base-catalyzed, one-pot synthesis of highly functionalized cinnolines
  76. The experimental study on the air oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid with Co–Mn–Br system
  77. Highly efficient removal of tetracycline and methyl violet 2B from aqueous solution using the bimetallic FeZn-ZIFs catalyst
  78. A thermo-tolerant cellulase enzyme produced by Bacillus amyloliquefaciens M7, an insight into synthesis, optimization, characterization, and bio-polishing activity
  79. Exploration of ketone derivatives of succinimide for their antidiabetic potential: In vitro and in vivo approaches
  80. Ultrasound-assisted green synthesis and in silico study of 6-(4-(butylamino)-6-(diethylamino)-1,3,5-triazin-2-yl)oxypyridazine derivatives
  81. A study of the anticancer potential of Pluronic F-127 encapsulated Fe2O3 nanoparticles derived from Berberis vulgaris extract
  82. Biogenic synthesis of silver nanoparticles using Consolida orientalis flowers: Identification, catalytic degradation, and biological effect
  83. Initial assessment of the presence of plastic waste in some coastal mangrove forests in Vietnam
  84. Adsorption synergy electrocatalytic degradation of phenol by active oxygen-containing species generated in Co-coal based cathode and graphite anode
  85. Antibacterial, antifungal, antioxidant, and cytotoxicity activities of the aqueous extract of Syzygium aromaticum-mediated synthesized novel silver nanoparticles
  86. Synthesis of a silica matrix with ZnO nanoparticles for the fabrication of a recyclable photodegradation system to eliminate methylene blue dye
  87. Natural polymer fillers instead of dye and pigments: Pumice and scoria in PDMS fluid and elastomer composites
  88. Study on the preparation of glycerylphosphorylcholine by transesterification under supported sodium methoxide
  89. Wireless network handheld terminal-based green ecological sustainable design evaluation system: Improved data communication and reduced packet loss rate
  90. The optimization of hydrogel strength from cassava starch using oxidized sucrose as a crosslinking agent
  91. Green synthesis of silver nanoparticles using Saccharum officinarum leaf extract for antiviral paint
  92. Study on the reliability of nano-silver-coated tin solder joints for flip chips
  93. Environmentally sustainable analytical quality by design aided RP-HPLC method for the estimation of brilliant blue in commercial food samples employing a green-ultrasound-assisted extraction technique
  94. Anticancer and antimicrobial potential of zinc/sodium alginate/polyethylene glycol/d-pinitol nanocomposites against osteosarcoma MG-63 cells
  95. Nanoporous carbon@CoFe2O4 nanocomposite as a green absorbent for the adsorptive removal of Hg(ii) from aqueous solutions
  96. Characterization of silver sulfide nanoparticles from actinobacterial strain (M10A62) and its toxicity against lepidopteran and dipterans insect species
  97. Phyto-fabrication and characterization of silver nanoparticles using Withania somnifera: Investigating antioxidant potential
  98. Effect of e-waste nanofillers on the mechanical, thermal, and wear properties of epoxy-blend sisal woven fiber-reinforced composites
  99. Magnesium nanohydroxide (2D brucite) as a host matrix for thymol and carvacrol: Synthesis, characterization, and inhibition of foodborne pathogens
  100. Synergistic inhibitive effect of a hybrid zinc oxide-benzalkonium chloride composite on the corrosion of carbon steel in a sulfuric acidic solution
  101. Review Articles
  102. Role and the importance of green approach in biosynthesis of nanopropolis and effectiveness of propolis in the treatment of COVID-19 pandemic
  103. Gum tragacanth-mediated synthesis of metal nanoparticles, characterization, and their applications as a bactericide, catalyst, antioxidant, and peroxidase mimic
  104. Green-processed nano-biocomposite (ZnO–TiO2): Potential candidates for biomedical applications
  105. Reaction mechanisms in microwave-assisted lignin depolymerisation in hydrogen-donating solvents
  106. Recent progress on non-noble metal catalysts for the deoxydehydration of biomass-derived oxygenates
  107. Rapid Communication
  108. Phosphorus removal by iron–carbon microelectrolysis: A new way to achieve phosphorus recovery
  109. Special Issue: Biomolecules-derived synthesis of nanomaterials for environmental and biological applications (Guest Editors: Arpita Roy and Fernanda Maria Policarpo Tonelli)
  110. Biomolecules-derived synthesis of nanomaterials for environmental and biological applications
  111. Nano-encapsulated tanshinone IIA in PLGA-PEG-COOH inhibits apoptosis and inflammation in cerebral ischemia/reperfusion injury
  112. Green fabrication of silver nanoparticles using Melia azedarach ripened fruit extract, their characterization, and biological properties
  113. Green-synthesized nanoparticles and their therapeutic applications: A review
  114. Antioxidant, antibacterial, and cytotoxicity potential of synthesized silver nanoparticles from the Cassia alata leaf aqueous extract
  115. Green synthesis of silver nanoparticles using Callisia fragrans leaf extract and its anticancer activity against MCF-7, HepG2, KB, LU-1, and MKN-7 cell lines
  116. Algae-based green AgNPs, AuNPs, and FeNPs as potential nanoremediators
  117. Green synthesis of Kickxia elatine-induced silver nanoparticles and their role as anti-acetylcholinesterase in the treatment of Alzheimer’s disease
  118. Phytocrystallization of silver nanoparticles using Cassia alata flower extract for effective control of fungal skin pathogens
  119. Antibacterial wound dressing with hydrogel from chitosan and polyvinyl alcohol from the red cabbage extract loaded with silver nanoparticles
  120. Leveraging of mycogenic copper oxide nanostructures for disease management of Alternaria blight of Brassica juncea
  121. Nanoscale molecular reactions in microbiological medicines in modern medical applications
  122. Synthesis and characterization of ZnO/β-cyclodextrin/nicotinic acid nanocomposite and its biological and environmental application
  123. Green synthesis of silver nanoparticles via Taxus wallichiana Zucc. plant-derived Taxol: Novel utilization as anticancer, antioxidation, anti-inflammation, and antiurolithic potential
  124. Recyclability and catalytic characteristics of copper oxide nanoparticles derived from bougainvillea plant flower extract for biomedical application
  125. Phytofabrication, characterization, and evaluation of novel bioinspired selenium–iron (Se–Fe) nanocomposites using Allium sativum extract for bio-potential applications
  126. Erratum
  127. Erratum to “Synthesis, characterization, and evaluation of nanoparticles of clodinofop propargyl and fenoxaprop-P-ethyl on weed control, growth, and yield of wheat (Triticum aestivum L.)”
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