Discovery of thiosemicarbazone derivatives as effective New Delhi metallo-β-lactamase-1 (NDM-1) inhibitors against NDM-1 producing clinical isolates

@#New Delhi metallo-β-lactamase-1 (NDM-1) is capable of hydrolyzing nearly all β-lactam antibiotics, posing an emerging threat to public health. There are currently less effective treatment options for treating NDM-1 positive “superbug”, and no promising NDM-1 inhibitors were used in clinical practice. In this study, structure–activity relationship based on thiosemicarbazone derivatives was systematically characterized and their potential activities combined with meropenem (MEM) were evaluated. Compounds 19bg and 19bh exhibited excellent activity against 10 NDM-positive isolate clinical isolates in reversing MEM resistance. Further studies demonstrated compounds 19bg and 19bh were uncompetitive NDM-1 inhibitors with Ki = 0.63 and 0.44 μmol/L, respectively. Molecular docking speculated that compounds 19bg and 19bh were most likely to bind in the allosteric pocket which would affect the catalytic effect of NDM-1 on the substrate meropenem. Toxicity evaluation experiment showed that no hemolysis activities even at concentrations of 1000 mg/mL against red blood cells. In vivo experimental results showed combination of MEM and compound 19bh was markedly effective in treating infections caused by NDM-1 positive strain and prolonging the survival time of sepsis mice. Our finding showed that compound 19bh might be a promising lead in developing new inhibitor to treat NDM-1 producing superbug.

Synthesis And Biological Evaluation Of Thiosemicarbazone Analogues Of Ornidazole As Antifungal Agents

To synthesize a series of ornidazole thiosemicarbazone analogues on the basis of literature reviews of 2-Methyl-5-nitroimidazoles and thiosemicarbazones and to evaluate all the analogues in vitro for their activity against Aspergillus niger and fumigatus. Thiosemicarbazone analogues were synthesized from oxidising ornidazole with potassium dichromate and refluxing the oxidised product with substituted thiosemicarbazide using ethanol as solvent in the acidic medium overnight. All the synthesized analogues of ornidazole showed good antifungal action against fumigatus and niger except compound C-4. Unsubstituted amine analogue C-2 has shown highest percentage inhibition (96.6%, 500 μg/ml) against fumigatus while aromatic amine with or without electronegative atom analogues C-3 and C-5 has shown highest activity against Aspergillus niger which is two times than standard drug ornidazole (100%, 1000 μg/ml).

Efecto citotóxico de los compuestos de inclusión de paladio (II) en la beta-ciclodextrina / Cytotoxic effect of palladium (II) inclusion compounds in beta-cyclodextrin

Resumen Introducción. Las tiosemicarbazonas y sus complejos de paladio (II) poseen actividad antineoplásica con pocos efectos secundarios, por lo cual se las considera como una nueva alternativa terapéutica. Sin embargo, existen diferencias en los rangos de la concentración inhibitoria media (CI50) asociada a la divergencia estructural y la solubilidad de los complejos, así como a la sensibilidad de los blancos celulares. La inclusión de fármacos en la beta-ciclodextrina con fines terapéuticos ha mejorado su solubilidad y estabilidad, pero los efectos de su combinación con los complejos de paladio (II) y las tiosemicarbazonas no se han comprobado aún. Objetivo. Estudiar el efecto citotóxico de los complejos de paladio en la beta-ciclodextrina. Materiales y métodos. La actividad citotóxica de los complejos de paladio en la beta-ciclodextrina se evaluó en la línea celular de cáncer de mama (MCF-7), empleando el método de la sulforodamina B. Resultados. Los ligandos MePhPzTSC y Ph2PzTSC, sus complejos de paladio (II) libres e incluidos en la beta-ciclodextrina y el cisplatino mostraron actividad citotóxica en la línea celular MCF-7; sin embargo, la citotoxicidad fue mayor con la inclusión en la beta-ciclodextrina ([Pd(MePhPzTSC)2]•ß-CD y [Pd(Ph2PzTSC)2]•ß-CD). La concentración inhibitoria media (CI50) para estos complejos se obtuvo en concentraciones de 0,14 y 0,49 μM, y con dosis hasta cinco veces inferiores comparadas con las concentraciones de los ligandos libres (1,4 y 2,9 μM), de los complejos de paladio (II) libres (0,57 y 1,24 μM) y del cisplatino (6,87 μM). Conclusiones. El uso de la beta-ciclodextrina mejoró significativamente la actividad citotóxica de las tiosemicarbazonas y sus complejos de paladio (II), lo cual probablemente está asociado al incremento de la solubilidad y biodisponibilidad del compuesto, estrategia que se puede sugerir para el diseño de futuros fármacos antineoplásicos.

Abstract Introduction: Thiosemicarbazones and palladium (II) complexes have antineoplastic activities with mild side effects, for which they are considered new alternative antineoplastic drugs. However, the IC50 ranges of these complexes vary due to differences in their structure and solubility and their sensitivities for various cellular targets. Beta-cyclodextrin is an additive used to improve the solubility and stability of various drugs for therapeutic use, but the combination of beta-cyclodextrin with palladium (II) complexes and thiosemicarbazones has not been tested yet. Objective: To study the cytotoxic effect of palladium (II) inclusion complexes in beta-cyclodextrin. Materials and methods: We tested the cytotoxic activity of palladium complexes combined with betacyclodextrin in the breast cancer cell line MCF-7 using a sulforhodamine B assay. Results: We tested the antiproliferative activity of palladium (II) complexes with and without the ligands MePhPzTSC and Ph2PzTSC and with and without beta-cyclodextrin in MCF-7 cells and compared them to that of cisplatin. All combinations showed antiproliferative activity; however, the activity was greater for the combinations that included beta-cyclodextrin: ([Pd (MePhPzTSC) 2] • ß-CD and [Pd (Ph2PzTSC) 2] • ß-CD), at concentrations of 0.14 and 0.49 μM, respectively. The IC50 for this complex was 5-fold lower than that of the ligand-free combinations (1.4 and 2.9 μM, respectively). The IC50 for free palladium (II) complex was 0.571.24 μM and that for cisplatin was 6.87 μM. Conclusions: Beta-cyclodextrin significantly enhanced the cytotoxic activities of palladium (II) complexes and thiosemicarbazones probably by improving their solubility and bioavailability. The addition of betacyclodextrin is a possible strategy for designing new anticancer drugs.

Synthesis, spectral aspects and biological activities of 5-hydroxy-2-nitrobenzaldehydethiosemicarbazone and their Mn(II), Co(II) and Ni(II) complexes.

The ligation behavior of 5-hydroxy-2-nitrobenzaldehydethiosemicarbazone (L) and its Mn(II), Co(II) and Ni(II) complexes has been synthesized and characterized by Elemental analysis, Electronic, FT-IR, Raman, EPR spectral techniques and Cyclic voltammetric study. The ligand (L) belongs to triclinic system with P1 space group. The IR spectral data of ligand indicate the taking part of sulphur and azomethine nitrogen in coordination to the central metal ion. The electronic, FT-IR and EPR spectral studies reveals all the complexes are distorted octahedral geometry. The synthesized ligand and its metal(II) complexes were tested for their antioxidant activity by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method and antibacterial activity against E.coli, Staphylococcus aureus, Bacillus subtilis, Salmonella typhi and Klebsiella pneumonia. The antibacterial and antioxidant activities of the ligand and its metal complexes had shown moderate to good activity, among all the compounds Ni(II) complex had shown more activity.

Synthesis and antitumor activities of fluoroquinolone C-3 isosteres(VIII):s-triazole sulfide-one thiosemicarbazone derivatives from pefloxacin / 中国药科大学学报

@#To improve the antitumor activity of fluoroquinolones for a promising development of druggability, twelve novel fluoroquinolone C-3 s-triazole sulfide-one thiosemicarbazone derivatives(6a-6l)were designed and synthesized with a functionalized sulfide-one thiosemicarbazone as a modified side-chain for the C-3 bioisteric s-triazole ring of pefloxacin(1). The structures were characterized by elemental analysis and spectral data。The in vitro antitumor activity of novel compounds against SMMC-7721, L1210 and HL60 cell lines was evaluated. The preliminary pharmacological results demonstrated that the title compounds exhibited more significantly antiproliferative activity than either the parent 1 or the corresponding sulfide-one intermediates(5a-5l). In particular, compounds bearing a hydroxyl group or a fluorine atom attached to benzene ring were comparable to the control doxorubicin with an IC50 value of micro-molar concentration, respectively. It suggests that an azole ring modified with functional side-chain instead of the C-3 carboxylic group is favorable to the improve ment of antitumor activity.

Design, synthesis and spectral characterization of 5-[2(3)-dialkylamino alkoxy] indole 3-hydrazone 2-one and 5-hydroxyindole 3-thiosemicarbazone 2-ones.

In the present work, some new 5-[2(3)-dialkylamino alkoxy] Indole 3-hydrazone 2-one and 5-[2(3)-dialkylamino alkoxy] indole 3-thiosemicarbazone 2- ones were prepared from 5-hydroxy isatin. The structures of the products were characterized by IR, NMR, MASS Spectral studies. Simplicity of the reaction conditions, easy workup procedure and good yields are the key features of this protocol.

Synthesis and biological activity of acetylacetone thiosemicarbazone and their metallic complexes.

In present work, Ligand acetylacetone thiosemicarbazone and their 11 complexes of the type ML2X2, ML2X’, where M = Cu(II), Cd(II), Co(II), Zn(II), Hg(II); L = acetylacetone thiosemicarbazone; X = Cl, NO3 or CH3COO; X’ = SO4 have been synthesized and characterized with the help of molar conductance, magnetic susceptibility measurements, infra-red and ultra-violet spectroscopy. The spectral data revealed that the thiosemicarbazone act as bidentate ligand, making use of thionic sulphur and the azomethine nitrogen atom for co-ordination to the central metal atom. All the compounds have been screened for their antibacterial activity against Gram positive bacteria Staphylococcus aureus, Staphylococcus epidermidis and Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. Some of complexes exhibited appreciable activity.

Synthesis and biological activity of acetylacetone thiosemicarbazone and their metallic complexes.

In present work, Ligand acetylacetone thiosemicarbazone and their 11 complexes of the type ML2X2, ML2X’, where M = Cu(II), Cd(II), Co(II), Zn(II), Hg(II); L = acetylacetone thiosemicarbazone; X = Cl, NO3 or CH3COO; X’ = SO4 have been synthesized and characterized with the help of molar conductance, magnetic susceptibility measurements, infra-red and ultra-violet spectroscopy. The spectral data revealed that the thiosemicarbazone act as bidentate ligand, making use of thionic sulphur and the azomethine nitrogen atom for co-ordination to the central metal atom. All the compounds have been screened for their antibacterial activity against Gram positive bacteria Staphylococcus aureus, Staphylococcus epidermidis and Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. Some of complexes exhibited appreciable activity.

Spectroscopic and biological studies on newly synthesized copper (II) and nickel (II) complexes with p-Dimethylaminobanzaldehyde semicarbazone and p-Dimethylaminobanzaldehyde thiosemicarbazone.

Cu (II) and Ni (II) complexes of general composition [ML2]X2 (M = Cu(II), Ni(II); X = Cl-, NO3 -) were synthesized by the condensation of metal salts with semicarbazone / thiosemicarbazone derived from pdimethylaminobanzaldehyde. The metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR and atomic absorption spectral studies. On the basis of electronic and infrared spectral studies, the metal complexes were found to have tetrahedral geometry. The Schiff bases and their metal complexes were tested for their antibacterial and antioxidant activities.

In-vitro studies of some carbonyl derivatives on liver acid phosphatase.

For a compound to be pharmacologically/ therapeutically active interaction of the compound with biologically significant molecules exists. It may be with a protein molecule, receptor site, enzyme, nucleic acid etc. In the present work we have evaluated the effect of semicarbazones, thiosemicarbazones and hydrazones of simple aryl aldehydes on the activity of liver acid phosphatase.

Anti-parasitic action and elimination of intracellular Toxoplasma gondii in the presence of novel thiosemicarbazone and its 4-thiazolidinone derivatives

Toxoplasma, which infects all eukaryotic cells, is considered to be a good system for the study of drug action and of the behavior of infected host cells. In the present study, we asked if thiosemicarbazone derivatives can be effective against tachyzoites and which morphological and ultrastructural features of host cells and parasites are associated with the destruction of Toxoplasma. The compounds were tested in infected Vero cell culture using concentration screens (0.1 to 20 mM). The final concentration of 1 mM was chosen for biological assay. The following results were obtained: 1) These new derivatives decreased T. gondii infection with an in vitro parasite IC50 percent of 0.2-0.7 mM, without a significant effect on host cells and the more efficient compounds were 2, 3 (thiosemicarbazone derivatives) and 4 (thiazolidinone derivative); 2) The main feature observed during parasite elimination was continuous morphological disorganization of the tachyzoite secretory system, progressive organelle vesiculation, and then complete disruption; 3) Ultrastructural assays also revealed that progressive vesiculation in the cytoplasm of treated parasites did not occur in the host cell; 4) Vesiculation inside the parasite resulted in death, but this feature occurred asynchronously in different intracellular tachyzoites; 5) The death and elimination of T. gondii was associated with features such as apoptosis-like stage, acidification and digestion of parasites into parasitophorous vacuoles. Our results suggest that these new chemical compounds are promising for the elimination of intracellular parasites by mainly affecting tachyzoite development at 1 mM concentration for 24 h of treatment.