2-Butanone thiosemicarbazone ligand was prepared by condensation reaction between thiosemicarbazide and butanone. The ligand was characterized by 1H NMR, 13C NMR, FT-IR, mass spectrometry and UV spectroscopic studies. Docking studies were performed to study inhibitory action against topoisomerase II (Topo II) and ribonucleoside diphosphate reductase (RR) enzymes. Inhibition constants (K
 i
 ) of the ligand were 437.87 and 327.4 μM for the two enzymes, respectively. The ligand was tested for its potential anticancer activity against two cancer cell lines MDA-MB-231 and A549 using MTT assay and was found to exhibit good activity at higher doses with an IC50 = 80 μM against human breast cancer cell line MDA-MB-231. On the other hand, no significant activity was obtained against the lung carcinoma cell line A549. Antibacterial activity of the ligand was tested against Staphylococcus aureus and E. coli using the disc diffusion method. Ligand did not exhibit any significant antibacterial activity. Four complexes of Co(III), Fe(II), Cu(II), and Zn(II) were prepared with the ligand and characterized by various spectroscopic studies. Low molar conductance values were obtained for all complexes displaying non-electrolyte nature except in Co(III) complex. As expected, complexation with metal ions significantly increased the cytotoxicity of the ligand against the tested cell lines viz. IC50 values of <20 μM for Co, Fe, and Zn complexes and approx. 80 μM against MDA cells versus IC50 value of <20 μM for Co and Cu complexes and that of 30 and 50 μM for Fe and Zn complexes, respectively, against A549 cells. The Cu complex was found to be active against E. coli and S. aureus with MIC values in the range of 6–10 mg/mL. Other than Cu, only Co complex was found to possess antibacterial activity with MIC values of 5–10 mg/mL when tested against S. aureus. Bioactivity score and Prediction of Activity Spectra for Substances (PASS) analysis also depicted the drug-like nature of ligand and complexes.

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Molecular docking, PASS analysis, bioactivity score prediction, synthesis, characterization and biological activity evaluation of a functionalized 2-butanone thiosemicarbazone ligand and its complexes.

A catalytic atroposelective cycloaddition reaction between thioureas and ynals is developed. This reaction features the first NHC-catalyzed addition of thioureas to acetylenic acylazolium intermediates to eventually set up C-N axial chirality with excellent optical purities. The obtained axially chiral thiazine derivative products bear multiple functional groups and are feasible for further transformations.

N-Heterocyclic Carbene-Catalyzed Atroposelective Annulation for Access to Thiazine Derivatives with C-N Axial Chirality.

A series of novel copper (II) and nickel (II) complexes derived from chiral Schiff-base ligands [(R)/(S)-H2L(1)=(R)/(S)-2-[(1-Hydroxymethyl-propylimino)-methyl]-5-methoxy-phenol and (R)/(S)-H2L(2)=(R)/(S)-2-[(1-Hydroxymethyl-2-phenyl-ethylimino)-methyl]-5-methoxy-phenol], were synthesized and characterized by elemental analyses, (1)H NMR spectra, FT-IR spectrum. The crystal structures of complexes 1-5 were determined through single crystal X-ray diffraction (SXRD). The structures showed the ligands coordinated to the Cu/Ni (II) ion in a neutral manner via ONO donor atoms, and oxygen atoms of solvent molecules occupy the axial positions in Ni (II) complexes 3 and 4. The complexes interactions with BSA and CT-DNA were investigated by various spectroscopic methods (UV-Visible, circular dichroism spectrum, fluorescence spectroscopic and synchronous fluorescence spectra). Interactions of chiral copper (II) complexes are stronger than nickel (II) complexes. Further, the cytotoxicities of the complexes 1-6 towards three kinds of cancerous cell lines, were human lung adenocarcinoma (A549), human cervical carcinoma cell (HeLa) and human breast cancer cell (MCF-7) respectively, were evaluated by MTT assay. All complexes exhibited good cytotoxic activity. Furthermore, Cu (II) complex 5 derived from (R)-Schiff-base ligand was found to be more effective towards HeLa cancerous cell. The results showed that chirality and metal ion have important influence on their anticancer activities and interactions with DNA/BSA.

Cu(II), Ni(II) complexes derived from chiral Schiff-base ligands: Synthesis, characterization, cytotoxicity, protein and DNA-binding properties.

Structural, optical, morphology characterization and DFT studies of nano sized Cu(II) complexes containing schiff base using green synthesis

Dietary Tridax procumbens leaves extract stimulated growth, antioxidants, immunity, and resistance of Nile tilapia, Oreochromis niloticus, to monogenean parasitic infection

Molecular docking is a kind of bioinformatic modelling which involves the interaction of two or more molecules to give the stable adduct. Depending upon binding properties of ligand and target, it predicts the three-dimensional structure of any complex. Molecular docking generates different possible adduct structures that are ranked and grouped together using scoring function in the software. Docking simulations predict optimized docked conformer based upon total energy of the system. In spite of all potential approaches, ligand chemistry (tautomerism and ionization), receptor flexibility (single conformation of rigid receptor) and scoring function (differentiate true binding mode) still remained the challenge. Many important aspects of molecular docking in terms of its approaches, types, applications and challenges are briefly discussed in this article.

Molecular Docking: Approaches, Types, Applications and Basic Challenges

Schiff bases are a group of compounds prepared by the condensation of primary amines and active carbonyl compounds. The Schiff bases have a general structure RRʹC=N-Rʹʹ (where R, R’ and Rʹʹ are alkyl, cyclohexyl, hydroxyalky1, hydroxyary1, etc). Herein the different synthetic routes of Schiff Base complexes like, direct synthesis, in situ method, oxidation of coordinated secondary amine, amine exchange approach, metal exchange and ligand exchange reaction are reviewed. A concise survey of literature on the coordination modes of complexes of Schiff base ligands is also presented in this article. The coordination complexes have been successfully screened against different strains of bacteria where they depicted the potential antimicrobial behaviour.

Synthesis of schiff base metal complexes: a concise review

The design and synthesis of medicinal chemotherapeutic agents of copper with 2-(benzothiazol-2-yl iminomethyl)-phenol, 2-(benzothiazol-2-yliminomethyl)-valine, cyanoaceto (2-mer- captobenzylidene)-hydrazide, 2-(phenacyl bromide)-aminothiophenol, (2-mercaptobenzaldehyde) thio- semicarbazone, N-(phenacyl bromide)-2- yliminobenzothiazole, 2-aminobenzothiazole, benzothiazol-2-yliminomethyl)-phenol and 2-[(2E¹-aminobenzylidene)- amino]-benzenethiol were synthesized. The characterization was done by FTIR, 1H and 13C NMR, MS, TGA and elemental analysis. Interaction of complexes 8 and 9 with CT DNA was done by using UV-vis and fluorescence spectroscopy depicting the hyperchromic behaviour of complexes. The intrinsic binding constants (Kb) for complex 8 and 9 were 2.35 × 103 M-1 and 2.12 × 103 M-1. The cleavage studies of complex 8 and 9 were done with pBR322 plasmid showing the potential cleaving ability of the complexes at very low concentration. The gel electrophoresis pattern also demonstrated that the complex 8 alone or in presence of Cu (II) causes the nicking of supercoiled pBR322 and it seems to follow the mechanistic pathway involving generation of hydroxyl radicals that are responsible for initiating DNA strand scission. The molecular docking studies showed the minor groove binding behaviour of the complexes 8 and 9 with DNA. During the MTT assay against different cancer cell lines like SW480, HepG2, HT29 and HL60, all the complexes showed potential cytotoxic behaviour by giving effective IC50 close to Cisplatin. The bioactivity score and PASS analysis also depicted the drug like nature of the complexes. During the comet assay, apoptotic degradation of DNA in the presence of complex 8 and 9 was analysed by agarose gel electrophoresis and visualized by ethidium bromide staining.

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DNA Binding, Cleavage Activity, Molecular Docking, Cytotoxicityand Genotoxicity Studies of Newly Synthesized Copper Based MetalComplexes

DNA binding, artificial nuclease activity and cytotoxic studies of newly synthesized steroidal pyrimidines.

Thiazolidinones is the special class of heterocyclic compounds with a broad spectrum of biological activities such as anti-inflammatory, antiproliferative, antihistaminic, anti-HIV, hypnotic, anaesthetic, antifungal, anthelmintic and antiviral agents as well as CNS stimulants. Therefore researchers have synthesized these condensed heterocycles through different complex pathways as target structures for biological studies. This review focuses on the various strategies followed for the convenient synthesis of thiazolidinone based heterocyclic derivatives. The steps included condensation followed by cyclization of Schiff’s bases, either in a step-wise manner or in one pot under different conditions. Mercaptoacetic acid, thiolactic acid, chloroacetyl chloride, potassium thiocyanate, ethylchloro acetate and ammonium thiocyanate are the most common reagents used for the synthesis thiazolidinone appended on different heterocyclic skeletons.

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Shafia Mir

Papers

Molecular Docking: Approaches, Types, Applications and Basic Challenges

Synthesis of schiff base metal complexes: a concise review

DNA Binding, Cleavage Activity, Molecular Docking, Cytotoxicityand Genotoxicity Studies of Newly Synthesized Copper Based MetalComplexes

DNA binding, artificial nuclease activity and cytotoxic studies of newly synthesized steroidal pyrimidines.

Strategies for the Synthesis of Thiazolidinone Heterocycles