Characterization of a Novel Curcumin based Schiff base Ligand, Synthesized by Microwave Method

A new Schiff base ligand derived from curcumin and ethylenediamine has been synthesized by the microwave irradiation method. The synthesized ligand was characterized by using FT-IR, UV-VIS, Molar conductance, NMR, PL and DLS studies. The results confirmed that the successful formation of Curcumin Based Schiff Base ligand. The ligand synthesized was stable at room temperature, completely soluble in hot methanol/DMF, partially soluble in ethanol/DMSO/acetone and insoluble in water. The spectra studies of FTIR and UV-visible confirmed the formation of the azomethine group in the ligand. NMR spectrum confirmed the presence of aromatic proton, hydroxyl proton, amine proton etc in the ligand. The luminescent property of the ligand was confirmed by the photoluminescence spectroscopic method. The low molar conductance value showed the non-electrolytic nature of the ligand. The dynamic light scattering studies showed that the ligand synthesized was in nanometer scale. The structure of the ligand was also proposed based on the analysis reports.

Synthesis, spectroscopic and antimicrobial studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes derived from benzoic acid bidentate Schiff base ligand

The Schiff base was synthesized by condensation of 2-hydroxy-1-naphthaldehyde with 3- aminobenzoic acid in 1:1 molar ratio. The Schiff base ligand formed complexes with Co (II), Ni (II), Cu (II) and Zn (II) acetate via mechanochemical synthesis. The synthesized compounds were characterized by solubility test, thermal analysis, FT-IR, powder x-ray diffraction, molar conductance measurement, magnetic susceptibility and elemental analysis. The Schiff base has a melting point of 190 oC. The decomposition temperature of complexes was found to be in the range 289 – 302 oC. The Schiff base and its metal (II) complexes were soluble in DMF, DMSO and sparingly soluble in acetonitrile, chloroform, diethyl ether and insoluble in n-hexane which indicate the polar nature of the synthesized compounds. The IR spectral analysis of the free Schiff base shows a band at 1622 cm-1, assigned to v(C=N) stretching vibrations. This band was shifted in the spectra of complexes (1607 – 1633 cm-1), indicating coordination of the Schiff base to the metal ion through the azomethine group. The molar conductance of complexes determined are in the range 9.51 – 14.87 Ohm-1cm2mol-1 which indicate the non-electrolytic nature in DMF. Magnetic susceptibility measurements of Co (II), Ni (II) and Cu (II) complexes exhibit a magnetic moment in the range 1.25 – 3.08 BM. The values correspond to square-planar geometry. The magnetic moment value of Zn (II) complex indicates a diamagnetic behaviour. The elemental analysis of the complexes for C, H and N determined showed that the observed and the calculated percentages of the elements are in good agreement.

Synthesis, in vitro Antioxidant Activity, and Toxicity Evaluation of Hydrazone Derivatives Naphthalene-1-ylmethylene hydrazine

Hydrazone is a versatile organic compound that has a basic structure (-NHN=CH-) called the azomethine group. This structure is responsible for the physical and chemical of hydrazone, which makes this compound has variety bioactivities such as antioxidant, antitumor, and anticancer. In this work, two hydrazone derivatives from 1-naphthaldehyde and hydrazine (phenylhydrazine/hydrazine hydrate) have been synthesized under microwave irradiation. Their antioxidant activity and toxicity were evaluated by DPPH and BSLT method, respectively. Structures of the synthesized compounds were confirmed based on spectroscopic data included UV, FTIR, HRMS, and 1H-NMR. Based on the DPPH assay, hydrazone from phenylhydrazine has strong antioxidant (IC50 28.90 μg/mL) but inactive antioxidant for hydrazine hydrate (IC50 >1000 μg/mL). However, both compounds have a high toxicity effect on Artemia Salina Leach with each LC50 1.45 and 47.20 μg/mL, hence they have the potential to be developed into anticancer drugs.

Synthesis, DFT Calculations, Antiproliferative, Bactericidal Activity and Molecular Docking of Novel Mixed-Ligand Salen/8-Hydroxyquinoline Metal Complexes

Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2′-{1,2-ethanediylbis[nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR, 1H NMR, 13C NMR, UV–VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H2O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H2O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC50 values (1.49 and 1.95 µM, respectively) that were comparable to that of cisplatin (1.55 µM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC50 values of 1.95 and 1.43 µM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and -negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.

Synthesis and Spectral Characterization of Some New Novel Schiff bases Derived from Hydroxy Propiophenone

New Schiff bases derived by the condensation of methyl, chloro, and bromo substituted 2' hydroxy propiophenones with aliphatic and aromatic amines have been synthesized. The Schiff bases are yellow solids with sharp melting points. Schiff bases The spectral characterization of these newly synthesized Schiff base ligands has been done.These Schiff bases were characterized by IR spectroscopy, Nuclear magnetic resonance spectroscopy, UV spectroscopy, and Mass spectroscopy. IR spectra confirmed the presence of the phenolic OH group and azomethine group.

Organosilane-Functionalized Graphene Oxide Hybrid Material: Efficient Adsorbent For Heavy Metal Ions In Drinking Water

Organosilane-functionalized and chemically activated graphene-supported Schiff base ligand were synthesized and characterized with XRD, SEM, EDX, TEM, UV.-Vis., FT-IR and TG/DTA techniques. In the synthesis process, graphene oxide was firstly obtained with Hummer’ s method and reacted with 3-(trimethoxysilyl)propylamine. The last, the amine-activated and organosilane containing GO was reacted with 3,5-di-tert-butylsalicylaldehyde resulting the hybrid material (M) having azomethine group. The material (M) was used as an adsorbent in order to remove the cobalt(II) and zinc(II) ions in drinking water and standard solutions. The adsorption capacity of the material (M) to cobalt(II) and zinc(II) ions was investigated by batch method. Moreover, the effect of pH, contact time, temperature, and concentration on the adsorption capacity of the material was also investigated. The enrichment factors were calculated as 441 and 675 for zinc(II) and cobalt(II), respectively. The recovery performance of the material was determined in 98.65-101.75% and 98.55-104.0% range for zinc(II) and cobalt(II) ions, respectively.

Synthesis, X-ray Structure and Evaluation of Bactericidal Activity of an o-vanillin Functionalized Schiff Base

The present study reports the synthesis, crystal structure and evaluation of biological activities of a Schiff base, [L = (Z)-2-methoxy-6-(((2-methoxyphenyl) imino) methyl) phenol]. X-ray structure of Schiff base reveals that the compound crystallizes in the orthorhombic system with Pca space group. The Schiff base adopts two methoxy groups, one phenolic-OH and one azomethine group and exists in a Z-stereomer. Investigation on the self-assembled structure of the Schiff base exhibits the formation of a 3D supramolecular architecture through intermolecular O...H hydrogen bonding interactions. The bactericidal activity of the Schiff base has been examined against some pathogenic bacteria.