Microwave assisted Facile Green Synthesis, Characterization and Biological Evaluation of Organogermanium (IV) complexes

 

Anita Kumari, Renu Khedar, Taruna Pandey, R V Singh, Nighat Fahmi*

Department of Chemistry, University of Rajasthan, Jaipur, India 302004.

*Corresponding Author E-mail: anitasigger@yahoo.in, nighat.fahmi@gmail.com

 

ABSTRACT:

A green, straightforward, microwave-assisted method of synthesizing organogermanium complexes derived from 1-acetylferrocenehydrazinecarboxamide (AcSCZH) and 1-acetylferrocenehydrazinecarbothioamide (AcTSCZH) have been reported. For structural elucidation, elemental analysis, melting point measurements, and a mix of UV, IR, and 1H NMR spectroscopy methods were used to describe all of the produced compounds. According to physicochemical and spectroscopic investigations, the ligands are coupled to the Ge (IV) by azomethine nitrogen and the thiolicsulphur atom/enoloic oxygen atom. A trigonal-bipyramidal structure has been assigned to 1:1 germanium (IV) complexes, while an octahedral structure has been assigned to 1:2 germanium (IV) complexes. Antibacterial and antifungal activity of the compounds were investigated in vitro against human pathogenic bacteria and fungi respectively. The complexes' DNA cleavage abilities and antioxidant properties were also investigated. The present research work highlights the current progress in the development of germanium complexes as novel anti-oxidant and DNA cleavage agents.

 

KEYWORDS: Spectroscopic techniques, Antibacterial and Antifungal activities, DNA Cleavage abilities, Antioxidant activity.

 

 


INTRODUCTION: 

The notion of "green chemistry" emerged due to the large-scale manufacturing of pesticides, medicines, and petrochemicals that cause chemical pollution. Microwave-assisted methods for organic and inorganic synthesis in homogeneous media are becoming increasingly popular due to their numerous benefits, including reduced reaction time, higher yields of desired products,  lower energy consumption, and the avoidance of environmentally harmful solvents1-5. It is a powerful method for rapidly and efficiently synthesizing physiologically active compounds without the need to isolate any intermediates, resulting in atom economy and high selectivity6. As a result, the microwave approach has been effectively used to produce a variety of Schiff base complexes7-11. In diverse disciplines, many imines and their complexes have been investigated for their fascinating and crucial features12-14.

 

 

Photoluminescence materials15, organic light emitting diodes16-18, optical materials and technologies19,20, and sophisticated applications such as photovoltaic cells21 are all examples of their uses. The metal complexes of these compounds are used in medicine and pharmacy because of their biological effects, such as anticancer 22,23, antibacterial24,25, antimicrobial and antifungal.26–31 It was also recently revealed that small molecule phenolic Schiff base derivatives may be used to make bright chemosensors32-35. Schiff base derivatives have chemical and biological significance due to lone pair electrons in the sp2 hybridized orbital of the nitrogen atom of the azomethine group.36

 

Thiosemicarbazones that are most widely studied are the sulfur and nitrogen-based ligands37. The biological activities of acetylferrocenylthiosemicarbazone metal complexes have been reported. Acetylferrocenylthiosemicarbazone metal complexes may stop normal or altered tumor cells from multiplying38. Advances in organogermanium chemistry, notably in the domain of organogermanium derivatives with expanded pentacoordinated spheres, the majority of which are physiologically active compounds39, led us to conduct systematic research in this area. This paper describes the synthesis of the complexes [Ph2GeCl(AcSCZ)], [Ph2GeCl(AcTSCZ)], [Ph2Ge(AcSCZ)2] and [Ph2Ge(AcTSCZ)2] with a view to study the effect of coordination on antimicrobial, DNA cleavage and radical scavenging activities to explore the possibility of their use as potential biologicalagents.

 

MATERIALS AND METHODS:

Materials:

Alfa Aesar provided the reagents Ph2GeCl2, 1-acetylferrocene, semicarbazide hydrochloride, and thiosemicarbazide, which were used as such. Prior to usage, analytical grade solvents were distilled from suitable drying agents. The Rast Camphor technique was used to calculate molecular weights. Germanium was identified as GeO2 by gravimetric analysis. The Kjeldahl process measured nitrogen, while the Messenger method was used to quantify sulfur40. Using  a Nicolet Megna FTIR-550 spectrophotometer, the infrared spectra of the ligands and their complexes were recorded on KBr pellets (Shimadzu, USA). TheraChem, Sitapura, Jaipur, recorded 1H NMR spectra in DMSO-d6 using a Bruker-300MHz NMR spectrometer using TMS as the internal standard. The biological activities of the ligands and their complexes were examined at Dr. B. Lal Laboratory in Malviya Nagar, Jaipur.

 

Methods of Preparation of the Ligands:

For the sake of comparability, the ligands were synthesized using two alternative techniques. The environmentally friendly microwave aided synthesis and the traditional thermal technique are the two options.

 

Conventional Thermal Method:

The ligands (AcSCZH) and (AcTSCZH) were prepared by mixing 1-acetylferrocene (3.24g, 14.19mmol) with semicarbazide hydrochloride (1.58g, 14.19mmol) (in the presence of sodium acetate) and thiosemicarbazide (1.30g, 14.19mmol), respectively in a 1:1 molar ratio in ethanol. The reaction mixture was then allowed to stand for a few hours after being refluxed for 3–4 hours over a water bath. The ligands were purified and tested before use by recrystallization from the same solvent (ethanol). Tautomeric versions of the parent ligands are shown in Figure.1.

 

Figure 1: Tautomerism of the ligands.

 

Microwave Method:

1-acetylferrocene was dissolved in ethanol and added to the  ethnolic solutions of semicarbazide hydrochloride(in presence of anhydrous sodium acetate) (AcSCZH) and thiosemicarbazide (AcTSCZH). The reaction mixture was subjected to microwave irradiation for 4-5 minutes. On completion of the reaction, mixture was cooled at room temperature. When the precipitate of colored products obtained, filtered them, dried and recrystallized from ethanol.

 

Synthesis of the Complexes:

Conventional Thermal Method:

Concurrently, the compounds were made using traditional thermal techniques, using the same procedure as stated above. The thermal technique took 7-8 hours instead of 5-7 minutes to complete the reactions. The reaction mixture was heated under  reflux, and the white precipitate of NaCl generated was filtered off. Compounds were dried at low pressure for 2 hours. These were cleansed in the same way as the others. The purity was confirmed using TLC on silica gel-G with anhydrous methanol as a solvent.

 

Microwave Method:

For the synthesis of [Ph2Ge(AcSCZ)Cl], [Ph2Ge(AcTSCZ)Cl], [Ph2Ge(AcSCZ)2] and [Ph2Ge(AcTSCZ)2]  complexes, methanolic solution of Ph2GeCl2 (0.52g,1.74mmol )was mixed with the corresponding sodium salts of the ligands [AcSCZH(0. 512g,1.74mmol) and AcTSCZH(0.524g,1.74mmol)] in the ratios of 1:1 and 1:2 using few mL of methanol as a solvent and irradiated  in the in the microwave oven for 5-7 minutes. The products recovered from the microwave oven dissolved in dry methanol. The white precipitate of NaCl formed during the course of the reaction was recovered by filtration and the filtrate was dried under reduced pressure. The resulting products were repeatedly washed with petroleum ether and finally dried at 60şC/0.5 mm Hg for 2 h.(Table I)

 


 

Table 1: Physical parameters of all the synthesized ligands and complexes by conventional heating and microwave method.

Compounds

Color

M.P.

(°C)

Elemental analysis (%)

Found (Calc.)

Molar mass Found (Calc.)

C

H

N

S

Ge

Cl

AcSCZH

C13H15N3OFe

Brown

186

59.99

(60.47)

5.20

(5.86)

14.10

(14.74)

-

-

-

284.81

(285.13)

AcTSCZH

C13H15N3SFe

LightBrown

175

51.39

(51.84)

4.90

(5.02)

13.51

(13.95)

10.22

(10.65)

-

-

301.00

(301.19)

[Ph2Ge(AcSCZ)Cl]

C25H24N3OGeFeCl

Dark brown

130

54.59

(54.95)

4.24

(4.43)

7.30

(7.69)

-

12.89

(13.29)

6.01

(6.49)

546.22

(546.42)

[Ph2Ge(AcSCZ)2]

C38H38N6O2GeFe2

Coffee brown

142

56.90

(57.40)

4.52

(4.82)

10.07

(10.57)

-

8.70

(9.14)

-

795.00

(795.08)

[Ph2Ge(AcTSCZ)Cl]

C25H24N3SGeFeCl

Brown

125

52.77

(53.39)

4.12

(4.30)

6.89

(7.47)

5.16

(5.70)

12.28

(12.91)

5.99

(6.30)

562.31

(562.48)

[Ph2Ge(AcTSCZ)2]

C38H38N6S2GeFe2

Dark brown

148

54.67

(55.17)

4.45

(4.63)

9.85

(10.16)

7.50

(7.75)

8.44

(8.78)

-

827.06

(827.21)

 

Table 2: Comparison between microwave and thermal methods.

Compound

Conventional Method

Microwave Method

Yeild (%)

Solvent (mL)

Time(h)

Yeild (%)

Solvent (mL)

Time(min)

AcSCZH

77

80

4

82

3-5

5

AcTSCZH

81

80

3

88

2-3

4

[Ph2Ge(AcSCZ)Cl]

75

50

8

86

3-4

5

[Ph2Ge(AcSCZ)2]

74

45

7

87

3

7

[Ph2Ge(AcTSCZ)Cl]

77

50

7

90

4

6

[Ph2Ge(AcTSCZ)2]

72

50

8

83

3

7

 

 

Scheme 1: Preparation of organogermanium(IV) complexes in 1:1 and 1:2.

 

Biological Screening:

Antibacterial Activity:

Antibacterial activity of synthesized compounds was evaluated by the “Paper Disc Plate Method” using Inhibition Zone Technique41. The complexes were screened against Staphylococcus aureus and Klebseilla aerogenous bacteria. The reference drug used was Streptomycin.

 

Antifungal Activity:

The complexes were screened against Fusarium oxysporum and Aspergillus niger fungi. The antifungal activity of the synthesized compounds was evaluated by the Radial Growth Method42.

 

DNA Cleavage Analysis:

At room temperature, the DNA binding and cleavage assays were carried out. The DNA cleavage activity of the Ge(IV) complexes was investigated using agarose gel electrophoresis, and a 24hour old culture (primary culture) of Pseudomonas aeruginosa was taken and grown on nutrient broth (peptone-5g; beef extract-3g; NaCl-5g; distilled water -1000mL; pH-7.0 autoclaved at 121°C and pressure- 15psi). Pseudomonas aeruginosa was introduced into the medium (ATCC 27853).

 

The pellet from a 1000µL fresh bacterial culture was centrifuged (6000rpm for 10 minutes) and dissolved in 250µL of cell lyses buffer. 250µL saturated phenol, chloroform, and isoamyl alcohol mixture was added in a 25:24:1 ratio to this and incubated at -20°C for 1 hour. The top aqueous layer was then collected after centrifugation at 10,000rpm for 10 minutes. Two volumes of cold 100% alcohol and 50 µL of sodium acetate were added to the supernatant. Centrifugation was used to separate the precipitated DNA. The pellet was dried, collected, and dissolved in TE buffer (10mm Tris pH 8.0, 1mm EDTA) before being kept in the refrigerator.

 

The cleavage products were analysed using the agarose gel electrophoresis technique. DMF was used to manufacture test samples (1mg/mL). The samples (25g) were mixed with Pseudomonas aeruginosa DNA that had been isolated. The samples were incubated for 2 hours at 37 degrees Celsius, and then 20L of DNA sample (mixed 1:1 with bromophenol blue dye) was carefully loaded into the electrophoresis chamber wells, along with standard DNA marker containing TAE buffer (4.84g Tris base, pH 8.0, 0.5m EDTA/L), and then loaded onto an agarose gel and passed through a constant 50V of electricity for around 30 minutes. The gel was removed and stained with 10.0g/mL ethidium bromide for 10-15 minutes, after which the bands were photographed and examined under a UV transilluminator to measure the degree of DNA breakage, and the findings were compared to those obtained with a standard DNA marker.

 

Antioxidant activity (2,2-diphenyl-1-picrylhydrazyl) (DPPH) Radical Scavenging Activity):

The ability of the test sample compounds to scavenge DPPH radicals was evaluated. Initially, 1mL of 0.2mM DPPH dissolved in methanol was mixed with 0.1mL of samples at 250, 500, and 1000g/mL concentrations. In the dark, the reaction mixture was maintained at 28°C for 20minutes. The blank had methanol, and the control contained all of the compounds but not the sample. The absorbance at 517nm was measured using a UV-VIS spectrophotometer to determine the DPPH radical scavenging activity. The DPPH radical scavenging activity of ascorbic acid was also investigated for comparison. The following equation was used to compute the proportion of DPPH radical scavenger:

                                            A0-A1

Scanvenging effect (%) =-------------X 100

                                              A0

Where, A0 is the absorbance of the control reaction and A1 is the absorbance in the presence of the samples.

 

RESULTS AND DISCUSSION:

In unimolar and bimolar ratios, diphenylgermanium dichloride interacts with the sodium salts of the ligands AcSCZH and AcTSCZH, yielding [Ph2Ge(AcSCZ)Cl], [Ph2Ge(AcTSCZ)Cl], [Ph2Ge(AcSCZ)2], and [Ph2Ge(AcTSCZ)2] solids. In DMF and DMSO, they are soluble. The reactions were carried out in a completely dry methanolic medium, and the precipitation of NaCl occurred smoothly. The development of these complexes follows the Scheme 1 pattern.

Electronic Spectra:

The electronic spectra of the ligands and their organogermanium complexes have been studied. The ligand spectra show a broadband about 375nm, which might be attributed to the azomethine group's n- π* transition, which has a blue shift in the organogermanium complexes due to polarization within the >C=N chromophore formed by the germanium ligand chelation. The occurrence of a band at 320nm might be due to π-π* transitions in the ligands, which are substantially unchanged in germanium compounds.

 

IR Spectra:

The IR spectral data of the generated ligands and their compounds are shown in Table 3. The infrared spectra of the >C= N group in the ligands exhibit a strong band in the range 1620– 1612 cm–1 that shifts to a lower frequency in the complexes, showing that the azomethine nitrogen is coordinated to the germanium atom. The absorption bands at 3310 cm–1, 1036 cm–1, 1685 cm–1, and 950 cm–1 in ligands are assigned to (N-H), (C=S), (C=O), and (N-N), respectively. The bands at 1036 cm1 due to >C=S and 1680 cm–1 due to >C=O are pushed down in frequency in the complexes, showing sulphur and oxygen coordination to the germanium atom, respectively. The far IR spectra of these germanium compounds showed many new bands that were not present in the ligands' spectra. The v(Ge-O), v(Ge-S), and v(Ge-N) modes are responsible for these bands, which are located at in the range 890-895cm-1, 410-414 cm–1 and 679-690 cm–1, respectively.

 

1 H NMR Spectra:

The 1HNMR spectra of the compounds further confirm the bonding as mentioned above  (Table 3). The 1HNMR spectrum data of the ligands and their associated organogermanium (IV) complexes were obtained in DMSO-d6, using TMS as an internal standard. In the 1H NMR spectra of ligands, the singlet at 2.23 ppm due to NH2 protons remained practically constant, showing that the NH2 group does not participate in the coordination. The absence of an NH proton signal in the spectra of organogermanium complexes at 8.50-8.90 ppm indicates deprotonation of the –NH group and complexation and coordination with the germanium atom.

 

The ligands are clearly monofunctional bidentate in nature, based on those as mentioned above Physico-chemical and spectrum data. Because these ligands are monomeric, they have been ascribed a trigonalbipyramidal structure for 1:1 and an octahedral structure for 1:2 organogermanium (IV) complexes.

 

 

Table 3: IR and 1HNMR spectral data of the synthesized ligands and their Ge(IV) complexes

IR Spectral data(cm-1)

1HNMR Spectral  data (ppm)

Compounds

>C=N

νN-H

>C=O/C-O

>C=S/C-S

Ge←N

Ge-S

Ge-O

-NH

-NH2

-CH3

AcSCZH

1612

3310

1680

-

-

-

-

8.54

2.23

1.07

AcTSCZH

1620

3250

-

1036

-

-

-

8.90

2.31

1.10

[Ph2Ge( AcSCZ )Cl]

1608

-

1670

-

690

-

895

-

2.36

1.21

[Ph2Ge(AcSCZ)2]

1610

-

1674

-

685

-

890

-

2.38

1.24

[Ph2Ge(AcTSCZ)Cl]

1615

-

-

1020

680

414

-

-

2.42

1.24

[Ph2Ge(AcTSCZ)2]

1618

-

-

1025

679

410

-

-

2.43

1.25

 

Figure 2: Activity index of antibacterial activity of ligands and their germanium (IV) complexes.

 

Figure 3: Antifungal screening data for the ligands and their germanium (IV) complexes [inhibition after 96 h (%) (conc. in ppm)].


Bioassay:

Antimicrobial Assay:

According to the antimicrobial screening findings, both the ligands and their complexes suppressed the development of the tested bacterial and fungal species to varying degrees. The antibacterial (Figure. 2) and antifungal (Figure. 3) findings clearly show that their activity enhanced when the ligands were coupled to the germanium. Charge equilibration within the chelate ring decreases the polarities of the ligands and the core germanium atom, according to the chelation theory[43], which explains why chelates have greater activity than ligands. This increases the chelate's lipophilicity, enabling it to pass through the bacterial membranes lipoid layer. The efficacy of various chemicals against different species is influenced by the permeability of microorganisms' cells or changes in ribosomes of microbial cells. Concentration has also been considered a factor in increasing the degree of inhibition: as concentration increases, so doesthe activity. It's worth mentioning that the activity of the AcTSCZH-produced organogermanium complexes is greater than AcSCZH's. This might be due to the presence of sulfur atoms inthe ligand.

 

Antioxidant Activity:

Antioxidant supplements have been suggested in many studies to reduce oxidative stress and delay or prevent the development of disease-related complications44-46. The DPPH radical scavenging method was used to measure the ability of the test compounds to scavenge the DPPH radical. They contain a lot of antioxidants in (Figure.4). The hydrogen-donating activity was measured using DPPH radicals as the hydrogen acceptor, and the new molecule concentration and the percentage of inhibition showed a high correlation. The method depended on reducing an alcoholic DPPH solution in the presence of a hydrogen-donating antioxidant to produce the non- radical form DPPH-H.

 

 

Figure 4: % Scavenging effect of compounds toward 1,1-diphenyl-2-picrilhydrazyl (DPPH)

 

DNA Cleavage Activity:

The representative Schiff base ligands (AcSCZH andAcTSCZH) and their organogermanium complexes are studied for their DNA cleavage activity by agarose gelelectrophrorosis method against Pseudomonas aeruginosa (ATCC 27853). The characterization of DNA recognition bythe DNA cleavage chemistry that is associated with redox-active or photoactivated metal complexes. The electrophoresis analysis clearly revealed that the Schiff base and their metal complexes have acted on DNA as there was a difference in molecular weight between the control and the treated DNA samples. The difference was observed in the bands of lanes of complexes compared with the control DNA ofPseudomonas aeruginosa (ATCC27853)(Figure. 5) which is due to the relaxation of circular DNA into linear form. This shows that the control DNA alone does not show any apparent cleavage, whereas the Schiff bases and their complexes do show. In this work, the comparative data of DNA cleavage of organogermanium complexes showed that Ge(IV) complex with AcTSCZH has better activity towards cleavage of DNA, and all the other complexes exhibited better results than free ligands.

 

Figure 5: DNA cleavage gel diagram of synthesized compounds. Lane 1, control DNA of P.Aeruginosa; Lane 2, standard molecular weight marker(DNA ladder); Lanes 3 and 4, P.AeruginosaDNA treated with the ligands AcSCZH and AcTSCZH respectively; Lane 5-8 P.Aeruginosa DNA treated with [Ph2Ge( AcSCZH)Cl], [Ph2Ge(AcSCZH)2], [Ph2Ge(AcTSCZH)Cl] and [Ph2Ge(AcTSCZH)2] complexes, respectively

 

CONCLUSION:

Equipment that is available for purchase. The present work shows the advantages of microwave- assisted synthesis in synthesisingazomethine compounds, which are becoming more prominent in domains such as medicinal chemistry and drug development. Microwave irradiation was shown to be a more efficient and environmentally friendly approach to perform various inorganic syntheses with higher yields and shorter reaction durations when compared to classical synthesis. Analytical studies discovered the ligands to coordinate to the germanium atom in a monobasic bidentate manner. The antibacterial activity of the AcTSCZH and AcSCZH ligand complexes indicated that the latter is more active than the parent ligands. DNA cleavage studies also revealed that organogermanium complexes cleaved DNA better than ligands. The DPPH radical scavenging method was used to measure the ability of the test compounds to scavenge the DPPH radical. According to the DPPH studies, complexes scavenge DPPH to a significant degree. The proportion of scavenging activity increases dramatically as the concentration of the chemicals increases.

 

CONFLICT OF INTEREST:

The authors have no conflicts of interest.

 

ACKNOWLEDGEMENT:

The Authors are thankful to UGC, New Delhi for their financial assistance.

 

REFERENCES:

1.      Jadhav A A. Devale R P. Review on Microwave, The General purpose in Microwave Assisted Synthesis for Green Chemistry. Asian Journal of Research in Chemistry. 2022; 15(2):182-5. DOI: 10.52711/0974-4150.2022.00031.

2.      Jayalakshmi P M. Sheeba Jasmin T S. Jose M. Microwave Assisted Synthesis and Antibacterial Evaluation of 1, 3, 4-Thiadiazole Derivatives. Research Journal of Pharmacy and Technology. 2021; 14(10):5293-6.DOI:10.52711/0974-360X.2021.00923.

3.      Navale V A. Mokle S S. Vibhute A Y. Karamunge KG. KhansoleS V. Junne S B. Vibhute Y B. Microwave-Assisted Synthesis and Antibacterial Activity of Some New Flavones and 1, 5-Benzothiazepines.Asian Journal of  Research in Chemistry. 2009; 2(4): 472-475.

4.      Canton-Díaz A M. Munoz-Flores BM.MoggioI. Arias E.Turlakov G. Angel-Mosqueda, CD. Ramirez-Montes PI. Jimenez-Perez VM. Molecular structures, DFT studies and their photophysical properties in solution and solid state. Microwave-assisted multi component synthesis of organotin bearing Schiff bases. Journal of Molecular Structure. 2019;1180:642-650. DOI: https://doi.org/10.1016/j.molstruc.2018.12.039.

5.      Hanif M. Hassan M. Rafiq M.Abbas Q. Ishaq A. Shahzadi S. Seo S Y. Saleem M. Microwave-assisted synthesis, in vivo anti-inflammatory and in vitro anti-oxidant activities and molecular docking study of new substituted schiff base derivatives. Pharmaceutical Chemistry Journal. 2018;52:424-437. DOI: https://doi.org/10.1007/s11094-018-1835-0.

6.      AnastasP T.WarnerJ C. Green Chemistry: Theory and Practice, Oxford University Press,   New York. 1998. p.30.

7.      Tapabashi N O. Taha N I. El-Subeyhi M. Design Microwave Assisted Synthesis of Some Schiff Bases Derivatives of Congo Red and Conventional Preparation of Their Structurally Reversed Analogous Compounds. International Journal of Organic Chemistry. 2021; 11: 35-45. DOI: https://doi.org/10.4236/ijoc.2021.111004.

8.      Sathe P S. Pete U D, Bendre S R. Synthesis, Characterization and Investigation of Anti-Oxidant Activity of Hydrazide–hydrazone Derivatives of 2-(2-Isopropyl-5-methyl phenoxy) Acetohydrazide, Asian Journal of research in chemistry.2018; 11(3):533-538.DOI: 10.5958/0974-4150.2018.00095.0

9.      El-Wahaba H A. El-Fattahb M A. El-alfya H M Z. Owdaa M E. Linc L. Hamdya I.Synthesis and characterisation of sulphonamide (Schiff base) ligand and its copper metal complex and their efficiency in polyurethane varnish as flame retardant and antimicrobial surface coating additives.Progress in Organic Coatings. 2020; 142: 105577. DOI: https://doi.org/10.1016/j.porgcoat.2020.105577.

10.   Al-Hiyari B A. Shakya A K. Naik R R. Bardaweel S. Microwave-Assisted Synthesis of Schiff Bases of Isoniazid and Evaluation of Their Anti-Proliferative and Antibacterial Activities. Molbank. 2021; 1: M1189. DOI:https://doi.org/ 10.3390/M1189.

11.   Antony R. Arun T. Manickam S T D. A review on applications of chitosan-based Schiff bases.International Journal of Biological Macromolecules. 2019;129:615-633. DOI:https://doi.org/10.1016/j.ijbiomac.2019.02.047.

12.   Manjuraj T. Krishnamurthy G. Bodke D Y. Naik H S B. Shafeeulla M. Co(II), Ni(II) and Cu(II) complexes of new Mannich base of of N'-(1H-benzimidazol-1-ylmethyl) Pyridine-4-Carbohydrazide: Spectral, XRD, Molecular Docking, Antioxidant and Antimicrobial Studies. Asian Journal of Research in Chemistry. 2017; 10(4): 470-476. DOI: 10.5958/0974-4150.2017.00076.1

13.   Zianna  A. Geromichalos G D. Pekou A. Hatzidimitriou A G. Coutouli-Argyropoulou E. Lalia-Kantouri M. Pantazaki A A. Psomas G. A palladium(II) complex with the Schiff base 4-chloro-2-(nethyliminomethyl)-phenol: synthesis, structural characterization, and in vitro and in silico biological activity studies.Journal of Inorganic Biochemistry. 2019; 199: 110792-110806. DOI:https://doi.org/10.1016/j.jinorgbio.2019.110792.

14.   Wu D. GuoL. Li S J. Synthesis, structural characterization and anti-breast cancer activity evaluation of three new Schiff base metal (II) complexes and their nanoparticles. Journal of Molecular Structure.2020;1199:126938. DOI:https://doi.org/10.1016/j.molstruc.2019. 126938.

15.   Iwan A. Schab-Balcerzak E. Grucela-Zajac M. Skorka L. Structural characterization, absorption and photoluminescence study of symmetrical azomethines with long aliphatic chains. Journal of Molecular Structure. 2014; 1058:130-135. DOI:https://doi.org/10.1016/j. molstruc.2013.10.067.

16.   Zhang J. Xu L. Wong W Y. Energy materials based onmetal Schiff base complexes,Coordination Chemistry Reviews.  2018; 355: 180-198. DOI:https://doi.org/10.1016/j.ccr.2017.08.007.

17.   Sharbati M T. Rad M N S. Behrouz S. Gharavi A. Emami F.Near infrared organic light-emitting diodes based on acceptor–donor–acceptor (ADA) using novel conjugated isatin  Schiff bases. Journal of Luminescence. 2011; 131: 553-558. DOI:https://doi.org/10.1016/ j.jlumin.2010.10.016.

18.   García-López M C. Muńoz-Flores B M. Jiménez-PérezV M. Moggio I. Arias E. Chan-Navarro R. Santillan R. Synthesis and photophysical characterization of organotin compounds derived from Schiff bases for organic light emitting diodes. Dyes and Pigments. 2014;106:188-196. DOI:https://doi.org/10.1016/j.dyepig.2014.02.021.

19.   Bhumannavar V M. Patil P S. Gummagol N B. Structure Characterization, Spectroscopic investigation and Nonlinear Optical Study using Density Functional Theory of (E)-1-(4-Chlorophenyl)-3-(4-methylphenyl) prop-2-en-1-one. Asian Journal of Research in Chemistry. 2022; 15(2):121-8. DOI: 10.52711/0974-4150.2022.00019

20.   Arroudj S. Bouchouit M. Bouchouit K. Bouraiou A. Messaadia L. Kulyk B. Figa V. Bouacida S. Sofiani Z. Taboukhat S. Synthesis, spectral, optical properties and theoretical calculations on schiff bases ligands containing o-tolidine. Optical Materials. 2016; 56: 116-120. https://doi.org/10.1016/j.optmat.2015.12.046.

21.   Jeevadason A W. Murugavel K K. Neelakantan M A. Review on Schiff bases and their metal complexes as organic photovoltaic materials. Renewable and Sustainable Energy Reviews. 2014; 36: 220-227. DOI:https://doi.org/10.1016/j.rser.2014.04.060.

22.   Ahamad M N. Iman K. Raza M K. Kumar M. Ansari  A. Ahmad M. Shahid M. Anticancer properties, apoptosis and catecholase mimic activities of dinuclear cobalt(II) and copper(II) Schiff base complexes. Bioorganic Chemistry. 2020; 95: 103561. DOI:https://doi.org/10.1016/j.bioorg.2019.103561.

23.   Aslan H G.Akkoç S. Kökbudak Z. Anticancer activities of various new metal complexes prepared from a Schiff base on A549 cell line. Inorganic Chemistry Communications. 2020;111:107645. DOI:https://doi.org/10.1016/j.inoche.2019.107645.

24.   Vamsikrishna N. DaravathS. GanjiN. Pasha N.synthesis, structural characterization, DNA interaction, antibacterial and cytotoxicity studies of bivalent transition metal complexes of 6-aminobenzothiazole Schiff base. Inorganic Chemistry Communications. 2020; 113: 107767. DOI:https://doi.org/10.1016/j.inoche.2020. 107767.

25.   Albobaledi  Z. Esfahani M H. Behzad M. Abbasi A. Mixed ligand Cu(II) complexes of an unsymmetrical Schiff base ligand and N donorheterocyclic co-ligands: investigation of the effect of co-ligand on the antibacterial properties. Inorganica Chimica Acta. 2020; 499: 119185. DOI:https://doi.org/10.1016/j.ica.2019.119185.

26.   Vivekanand D B, Mruthyunjayaswamy B H M. Synthesis characterization and antimicrobial activity studies of some transition metal complexes derived from 3-chloro-6-methoxy-N’-((2-thioxo-1, 2-dihydroquinolin-3-yl) methylene)benzo[b] thiophene-2-carboxyhydrazide. Asian Journal of Research in Chemistry. 2013; 6(1):35-46.

27.   Nartop D. Özkan E H. Gündem M. Çeker S. Ağar G. Öğütcü H. Sarı N.Synthesis, antimicrobial and antimutagenic effects of novel polymeric Schiff bases including indol. Journal of Molecular Structure. 2019; 1195: 877-882. DOI:https://doi.org/10.1016/j.molstruc.2019.06.042.

28.   Satheesh C E. Kumar P R. Shivakumar N. Lingaraju K. Krishna P M. Rajanaika H. Hosamani A. Synthesis, structural characterization, antimicrobial and DNA binding studies of homoleptic zinc and copper complexes of NO Schiff bases derived from homoveratrylamine.InorganicaChimicaActa. 2019; 495: 118929. DOI:https://doi.org/10.1016/j.ica.2019.05.028.

29.   Joshi R. Kumari A. Singh K. Mishra H. Pokharia S. Triorganotin (IV) complexes of Schiff base derived from 1,2,4-triazole moiety: synthesis, spectroscopic investigation, DFT studies, antifungal activity and molecular docking studies. Journal of Molecular Structure. 2020; 1206: 1-15. DOI:https://doi.org/10.1016/j.molstruc.2019.127639

30.   Anita. Ghanghas P. Poonia K. Synthesis, Characterization, UTI and Antibacterial Activity of Schiff Base, (E)-2-(decan-2-ylidene) hydrazine-1-carboxamide Co2+, Mn2+ and Fe3+Metal Complexes. Asian Journal of Research in Chemistry. 2022; 15(2):145-0. DOI: 10.52711/0974-4150.2022.00023

31.   Muthuselvan P.  David S T. Nair M S. Transition Metal Schiff base Complexes with N, S and O donors – Synthesis, Characterisation and Antimicrobial Studies. Asian Journal of Research in Chemistry. 2011; 4(8):1305-1310.

32.   Süleymanoglu N. Ustabaş R.Unver Y. Alpaslan Y B. Direkel S. Karaman U.5-Phenyl thiophene amino phenol derivatives: synthesis, spectroscopic characterization, computational study and antimicrobial activity. Journal of Molecular Structure. 2019; 1182:36-46. DOI:https://doi.org/10.1016/j.molstruc.2019.01.005.

33.   Alyaninezhad Z. Bekhradnia A. Feizi N. Arshadi S. Zibandeh M.A novel aluminum-sensitive fluorescent chemosensor based on 4-aminoantipyrine: an experimental and theoretical study. Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy. 2019;212:32-41. DOI:https://doi.org/10.1016/j.saa.2018.12.035.

34.   Singh A. Tom S. Trivedi D R. Aminophenol based colorimetric chemosensor for naked-eye detection of biologically important fluoride and acetate ions in organo-aqueous medium: effective and simple anion sensors. Journal of Photochemistry and Photobiology A: Chemistry. 2018; 353: 507-520.DOI: https://doi.org/10.1016/j.jphotochem.2017.12. 002.

35.   Bai L. Tao F. Li L. Deng A. Yan C. Li G. Wang L.A simple turn-on fluorescent chemosensor based on Schiff base-terminated water-soluble polymer for selective detection of Al3+ in 100% aqueous solution. Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy. 2019; 214: 436-444. DOI:https://doi.org/10. 1016/j.saa.2019.02.062.

36.   Fahmi N.    Shrivastava S. Meena R.  Joshi S. C.  Singh R V. Microwave assisted synthesis, spectroscopic characterization and biological aspects of some new chromium(iii) complexes derived from N⁁O donor Schiff bases,  New Journal of Chemistry. 2013; 37: 1445-1453. DOI:(https://doi.org/10.1039/C3NJ40907D).

37.   Bonaccorso C. Marzo T. Mendola D L. Biological Applications of Thiocarbohydrazones and Their Metal Complexes: A Perspective Review. Pharmaceuticals. 2020; 13: 4-9. DOI:10.3390/ph13010004.

38.   Li M X. Chen C L. Zhang D. Niu J Y. Ji B S.  Mn(II), Co(II) and Zn(II) complexes with heterocyclic substituted thiosemicarbazones: synthesis, characterization, X-ray crystal structures and antitumor comparison. European Journal of Medicinal Chemistry. 2010; 45: 3169-3177. DOI: 10.1016/j.ejmech.2010.04.009.

39.   Kluska M. Some Aspects of the Analysis of Biologically Active Organogermanium Substances.Critical Reviews in Analytical Chemistry. 2008; 38: 84-92.DOI:https://doi.org/10.1080/10408340701804459.

40.   Vogel A I. A Textbook of Organic Quantitative Analysis, (Pearson Education Ltd.: Thames Polytechnique, London) 2004. p. 243.

41.   Fahmi N. Sharma K. Singh R V. Palladium(II) and platinum(II) derivatives of benzothiazoline ligands: Synthesis, characterization, antimicrobial and antispermatogenic activity. Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy. 2011; 78: 80.(https://doi.org/10.01016/j.saa.2010.08.076).

42.   Singh R V. Yadav S.Ferrocenyl-substituted Schiff base complexes of boron: Synthesis, structural, physico-chemical and biochemical aspects. Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy. 2011; 78: 298. (DOI:https://doi.org/10.1016/j.saa.2010.10.010.)

43.   Tweedy B G. Plant Extracts with Metal Ions as Potential Antimicrobial Agents. Phytopathology.1964; 55:910-918.

44.   Ahmed S A. Ansari A Q. Waheed M A. Sayyed J A. Extraction and determination of antioxidant activity of Withania somnifera Dunal. European Journal of Experimental Biology. 2013;3:502-507.

45.   Rahmani S E. Lahrech M Evaluation of the Antioxidant Activity of some Hydrazone Schiff’s bases bearing Benzotriazole Moiety. Research Journal of Pharmacy and Technology. 2018; 11(9):1-4.DOI: 10.5958/0974-360X.2018.00754.0

46.   Swathi N. Subrahmanyam C V S. Satyanarayana K . Synthesis and Quantitative Structure-Antioxidant Activity Relationship Analysis of Thiazolidine-2,4-dione Analogues.  Asian Journal of Research in Chemistry. 2015; 8(1): 21-26. DOI: 10.5958/0974-4150.2015.00005.X

 

 

 

 

Received on 01.05.2022            Modified on 15.11.2022

Accepted on 24.03.2023           © RJPT All right reserved

Research J. Pharm. and Tech 2023; 16(10):4703-4710.

DOI: 10.52711/0974-360X.2023.00764