Synthesis, characterization, and antioxidant activity of heterocyclic Schiff bases

Kızılkaya, Hakan; Dağ, Beşir; Aral, Tarık; Genç, Nusret; Erenler, Ram­azan

doi:10.1002/jccs.202000161

Cited by 36 publications

(18 citation statements)

References 28 publications

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“…Schiff bases containing imine ( C N ) or azomethine ( CH N ) groups are one of the most important class functional groups in organic chemistry due to their extensive biological and chemical properties. [1][2][3][4][5] The Schiff bases are also used as intermediates for the synthesis of important drugs, pesticides, and other natural products because of the conversion possibility of C N group to the desirable functional groups through reduction, addition, cyclization, and aziridination reactions. [6][7][8][9][10][11] Furthermore, antibacterial, anti-fungal, anti-oxidant, anti-tumor, anti-viral, anti-HIV, anti-inflammatory, and anti-proliferative properties of Schiff bases have been reported in the literature.…”

Section: Introductionmentioning

confidence: 99%

“…Schiff bases containing imine (CN) or azomethine (CHN) groups are one of the most important class functional groups in organic chemistry due to their extensive biological and chemical properties 1–5 . The Schiff bases are also used as intermediates for the synthesis of important drugs, pesticides, and other natural products because of the conversion possibility of CN group to the desirable functional groups through reduction, addition, cyclization, and aziridination reactions 6–11 .…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of new Schiff bases; Investigation of their in situ catalytic activity for Suzuki CC coupling reactions and antioxidant activities

Yılmaz

2021

J Chinese Chemical Soc

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New series of Schiff bases have been synthesized from the reaction between cyclohepta-2,4,6-trien-1-ylmethanamine and different aldehydes, and characterized via using 1 H NMR, 13 C NMR, FTIR spectroscopy, and GC-MS. After the successful synthesis, the in situ catalytic activity of all Schiff bases have been examined for the Suzuki C C cross-coupling reactions using phenylboronic acid, aryl bromides, and PdCl 2 as a catalyst. Before starting these investigations, reaction conditions were optimized using different bases and solvents. At the end of these reactions, the best efficiency was obtained in Et 3 N and EtOH. In addition to catalytic investigations, antioxidant activities of all synthesized Schiff bases were examined using DPPH and Iron (Fe 2+ ) chelation methods, and IC 50 values were calculated. While many molecules show various amounts of antioxidant activity, especially molecules 8e and 8g showed the best activity compared to butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), which were used as positive controls, in DPPH and Iron chelating methods, respectively.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis of new Schiff bases; Investigation of their in situ catalytic activity for Suzuki CC coupling reactions and antioxidant activities

Yılmaz

2021

J Chinese Chemical Soc

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“…To assess the mode of binding of Co 2+ with A , 1 H and 13 C‐NMR spectra of A were recorded in CDCl 3 with the indicated amounts of Co 2+ ions. The 1 H NMR spectrum of probe A displayed a singlet peak at δ 9.88 ppm, [44] which accounted for one proton. The singlet was attributable to the imine proton (−CH=N−), and the downfield shift suggested the involvement of imine proton in intramolecular H‐bonding (Figures 7, S8&S9).…”

Section: Resultsmentioning

confidence: 99%

Rotational Isomerization about C−C Single Bond in a Novel ICT Probe Facilitates Naked‐Eye, Colorimetric and Ratiometric Detection of Cobalt in Aqueous Samples**

Divya

Thennarasu

2021

ChemistrySelect

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A new UV‐active indole‐pyrazole extended π‐system (probe A) that displays a large bathochromic shift (∼325 nm) when it interacts only with Co2+ and not with other transition metal ions, is presented. The increase in the intensity of new transitions at 592 and 684 nm due to A−Co2+−Cl2.H2O complex formation occurs at the expense of the transition at 358 nm arising from the probe A, and thereby offers a ratiometric method for detection of Co2+ present in aqueous samples. The ratiometric method sets the detection limit for Co2+ at 0.404×10−6 M and 0.337×10−6 M, when calculated for the transitions at 592 and 684 nm, respectively. The corresponding association constants are 4.041×105 M−1 at 592 nm, and 3.617×105 M−1 at 684 nm. Job plot and ESI‐MS data confirmed the 1 : 1 stoichiometry of A−Co2+−Cl2.H2O complex. The mode of interaction between the probe A and Co2+ is explained in terms of conformational isomerization and chelation, using 1H NMR method and DFT calculations. Other metal ions commonly found in the environment do not seem to interfere in the selective determination of Co2+ ions. Suitability of probe A in the detection of Co2+ at concentrations less than 1.7 μM (recommended level of Co2+ ions by US‐EPA) is also demonstrated using water samples collected from the environment. Test kits suitable for routine on‐site analysis are also developed.

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“…There have been reports of compounds with fluorine substituent (C 0.5 FRAP = 424.5-502.6 µM) with potent antioxidant activities in FRAP [72]. Similarly, other reports have shown significant antioxidant activities of benzothiazole (553.5 mmol Fe 2+ /mmol Compound) [73] and thiophene (4.55 mmol TE/g compound) [74] derivatives. In this study, Q6 with fluorine substituent and perchlorate counter anion had the lowest ferric reducing power.…”

Section: In Vitro Antioxidant Studiesmentioning

confidence: 88%

Quinoline Functionalized Schiff Base Silver (I) Complexes: Interactions with Biomolecules and In Vitro Cytotoxicity, Antioxidant and Antimicrobial Activities

et al. 2021

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A series of fifteen silver (I) quinoline complexes Q1–Q15 have been synthesized and studied for their biological activities. Q1–Q15 were synthesized from the reactions of quinolinyl Schiff base derivatives L1–L5 (obtained by condensing 2-quinolinecarboxaldehyde with various aniline derivatives) with AgNO3, AgClO4 and AgCF3SO3. Q1–Q15 were characterized by various spectroscopic techniques and the structures of [Ag(L1)2]NO3Q1, [Ag(L1)2]ClO4Q6, [Ag(L2)2]ClO4Q7, [Ag(L2)2]CF3SO3Q12 and [Ag(L4)2]CF3SO3Q14 were unequivocally determined by single crystal X-ray diffraction analysis. In vitro antimicrobial tests against Gram-positive and Gram-negative bacteria revealed the influence of structure and anion on the complexes′ moderate to excellent antibacterial activity. In vitro antioxidant activities of the complexes showed their good radical scavenging activity in ferric reducing antioxidant power (FRAP). Complexes with the fluorine substituent or the thiophene or benzothiazole moieties are more potent with IC50 between 0.95 and 2.22 mg/mL than the standard used, ascorbic acid (2.68 mg/mL). The compounds showed a strong binding affinity with calf thymus-DNA via an intercalation mode and protein through a static quenching mechanism. Cytotoxicity activity was examined against three carcinoma cell lines (HELA, MDA-MB231, and SHSY5Y). [Ag(L2)2]ClO4Q7 with a benzothiazole moiety and [Ag(L4)2]ClO4Q9 with a methyl substituent had excellent cytotoxicity against HELA cells.

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Synthesis, characterization, and antioxidant activity of heterocyclic Schiff bases

Cited by 36 publications

References 28 publications

Synthesis of new Schiff bases; Investigation of their in situ catalytic activity for Suzuki CC coupling reactions and antioxidant activities

Synthesis of new Schiff bases; Investigation of their in situ catalytic activity for Suzuki CC coupling reactions and antioxidant activities

Rotational Isomerization about C−C Single Bond in a Novel ICT Probe Facilitates Naked‐Eye, Colorimetric and Ratiometric Detection of Cobalt in Aqueous Samples**

Quinoline Functionalized Schiff Base Silver (I) Complexes: Interactions with Biomolecules and In Vitro Cytotoxicity, Antioxidant and Antimicrobial Activities

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