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1.
J Enzyme Inhib Med Chem ; 37(1): 781-791, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35193444

ABSTRACT

Herein, we report the preparation of a panel of Schiff bases analogues as antiprotozoal agents by modification of the stereoelectronic effects of the substituents on N-1 and N-4 and the nature of the chalcogen atom (S, Se). These compounds were evaluated towards Trypanosoma cruzi and Trichomonas vaginalis. Thiosemicarbazide 31 showed the best trypanocidal profile (epimastigotes), similar to benznidazole (BZ): IC50 (31)=28.72 µM (CL-B5 strain) and 33.65 µM (Y strain), IC50 (BZ)=25.31 µM (CL-B5) and 22.73 µM (Y); it lacked toxicity over mammalian cells (CC50 > 256 µM). Thiosemicarbazones 49, 51 and 63 showed remarkable trichomonacidal effects (IC50 =16.39, 14.84 and 14.89 µM) and no unspecific cytotoxicity towards Vero cells (CC50 ≥ 275 µM). Selenoisosters 74 and 75 presented a slightly enhanced activity (IC50=11.10 and 11.02 µM, respectively). Hydrogenosome membrane potential and structural changes were analysed to get more insight into the trichomonacidal mechanism.


Subject(s)
Antiprotozoal Agents/pharmacology , Semicarbazones/pharmacology , Trichomonas vaginalis/drug effects , Trypanosoma cruzi/drug effects , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/chemistry , Dose-Response Relationship, Drug , Molecular Structure , Parasitic Sensitivity Tests , Semicarbazones/chemical synthesis , Semicarbazones/chemistry , Structure-Activity Relationship
2.
Molecules ; 26(21)2021 Oct 21.
Article in English | MEDLINE | ID: mdl-34770765

ABSTRACT

Two new series of betulin derivatives with semicarbazone (7a-g) or thiosemicarbazone (8a-g) groups at the C-28 position were synthesized. All compounds were evaluated for their in vitro cytotoxicities in human hepatocellular carcinoma cells (HepG2), human breast carcinoma cells (MCF-7), human lung carcinoma cells (A549), human colorectal cells (HCT-116) and normal human gastric epithelial cells (GES-1). Among these compounds, 8f displayed the most potent cytotoxicity with an IC50 value of 5.86 ± 0.61 µM against MCF-7 cells. Furthermore, the preliminary mechanism studies in MCF-7 cells showed that compound 8f could trigger the intracellular mitochondrial-mediated apoptosis pathway by losing MMP level, which was related with the upregulation of Bax, P53 and cytochrome c expression; the downregulation of Bcl-2 expression; activation of the expression levels of caspase-3, caspase-9, cleaved caspase-3 and cleaved caspase-9; and an increase in the amounts of intracellular reactive oxygen species. These results indicated that compound 8f may be used as a valuable skeleton structure for developing novel antitumor agents.


Subject(s)
Apoptosis/drug effects , Chemistry Techniques, Synthetic , Drug Design , Mitochondria/drug effects , Mitochondria/metabolism , Semicarbazones/chemistry , Semicarbazones/pharmacology , Triterpenes/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Biomarkers , Cell Line, Tumor , Cell Proliferation/drug effects , Flow Cytometry , Humans , Membrane Potential, Mitochondrial/drug effects , Metabolic Networks and Pathways/drug effects , Molecular Structure , Reactive Oxygen Species/metabolism , Semicarbazones/chemical synthesis
3.
J Inorg Biochem ; 220: 111468, 2021 07.
Article in English | MEDLINE | ID: mdl-33951554

ABSTRACT

The solution chemical properties such as proton dissociation, complex formation with copper(II) and gallium(III) ions in addition to antibacterial and antitumor activity of a novel tridentate salicyaldehyde semicarbazone-estrone hybrid (estrone-SC) and a related bicyclic compound (thn-SC) were investigated. The crystal structure of complex [Cu(thn-SCH-1)Cl] was studied by single crystal X-ray diffraction method. Estrone-SC and thn-SC form mono-ligand complexes with Cu(II) characterized by relatively high stability, however, they are much less stable than their thiosemicarbazone analogues. The neutral Cu(II) complexes with (O-,N,O-)(H2O) coordination mode predominate at physiological pH. Estrone-SC and thn-SC are more efficient Ga(III) binders in comparison with thiosemicarbazones, although the complexes also suffer dissociation at pH 7.4. The Cu(II) complex of estrone-SC displayed significant cytotoxicity in A549, SW480 and CH1/PA cancer cells, and moderate apoptosis induction and ROS formation. The semicarbazone compounds did not exhibit antibacterial effect; unlike the related Cu(II)-thiosemicarbazone complexes represented by the fairly low MIC values (3-50 µM) obtained on the Gram-positive Staphylococcus aureus and Enterococcus faecalis bacteria.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/pharmacology , Coordination Complexes/pharmacology , Estrone/analogs & derivatives , Estrone/pharmacology , Semicarbazones/pharmacology , Anti-Bacterial Agents/chemical synthesis , Antineoplastic Agents/chemical synthesis , Ascorbic Acid/chemistry , Bacteria/drug effects , Cell Line, Tumor , Coordination Complexes/chemical synthesis , Copper/chemistry , Drug Screening Assays, Antitumor , Gallium/chemistry , Glutathione/chemistry , Humans , Ligands , Molecular Structure , Reactive Oxygen Species/metabolism , Semicarbazones/chemical synthesis
4.
Bioorg Med Chem ; 29: 115891, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33278783

ABSTRACT

Ryanodine receptors (RyRs) are important ligand-gated Ca2+ channels; their excessive activation leads to Ca2+ leakage in the sarcoplasmic reticulum that may cause neurological diseases. In this study, three series of novel potent RyR1 inhibitors based on dantrolene and bearing semicarbazone and imidazolyl moieties were designed and synthesized, and their biological activity was evaluated. Using a single-cell calcium imaging method, the calcium overload inhibitory activities of 26 target compounds were tested in the R614C cell line, using dantrolene as a positive control. The preliminary investigation showed that compound 12a suppressed Ca2+ release as evidenced by store overload-induced Ca2+release (SOICR) (31.5 ± 0.1%, 77.2 ± 0.1%, 93.7 ± 0.2%) at 0.1 µM, 3 µM and 10 µM, respectively. Docking simulation results showed that compound 12a could bind at the active site of the RyR1 protein. The Morris water-maze test showed that compound 12a significantly improved the cognitive behavior of AD-model mice. Further studies on the structural optimization of this series of derivatives are currently underway in our laboratory.


Subject(s)
Alzheimer Disease/drug therapy , Calcium Channel Blockers/chemical synthesis , Neuroprotective Agents/chemical synthesis , Ryanodine Receptor Calcium Release Channel/metabolism , Semicarbazones/chemical synthesis , Animals , Calcium Channel Blockers/pharmacology , Calcium Signaling , Dantrolene/chemistry , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Humans , Imidazoles/chemistry , Male , Mice , Molecular Docking Simulation , Morris Water Maze Test , Neuroprotective Agents/pharmacology , Protein Binding , Protein Conformation , Semicarbazones/pharmacology , Single-Cell Analysis , Structure-Activity Relationship
5.
Bioorg Med Chem ; 28(13): 115557, 2020 07 01.
Article in English | MEDLINE | ID: mdl-32546298

ABSTRACT

Parthenolide is an important sesquiterpene lactone with potent anticancer activities. In order to further improve its biological activity, a series of parthenolide semicarbazone or thiosemicarbazone derivatives was synthesized and evaluated for their anticancer activity. Derivatives were tested in vitro against 5 human tumor cell lines, and many of these showed higher cytotoxicity than parthenolide. Five compounds were further studied for their antitumor activity in mice. The in vivo result indicated that compound 4d showed both promising antitumor activity against mice colon tumor and small side effects on immune systems. The cell apoptosis and cell cycle distribution of compound 4d were also studied. Molecular docking studies revealed multiple interactions between 4d and NF-κB. Our findings demonstrate the potential of semicarbazones as a promising type of compounds with anticancer activity.


Subject(s)
Antineoplastic Agents/chemical synthesis , Semicarbazones/chemical synthesis , Sesquiterpenes/chemistry , Thiosemicarbazones/chemical synthesis , Animals , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Carbamates/chemistry , Cell Line, Tumor , Cell Survival/drug effects , Drug Screening Assays, Antitumor , Humans , Male , Mice , Mice, Inbred C57BL , Molecular Docking Simulation , NF-kappa B/metabolism , Neoplasms, Experimental , Semicarbazones/pharmacology , Structure-Activity Relationship , Thiosemicarbazones/pharmacology
6.
Molecules ; 25(5)2020 Mar 07.
Article in English | MEDLINE | ID: mdl-32156024

ABSTRACT

A series of novel steroidal 5α,8α-endoperoxide derivatives bearing semicarbazone (7a-g) or thiosemicarbazone (7h-k) side chain were designed, synthesized and evaluated for their cytotoxicities in four human cancer cell lines (HepG2, HCT-116, MCF-7, and A549) using the MTT assay in vitro. The results showed that compound 7j exhibited significant cytotoxic activity against HepG2 cells (IC50 = 3.52 µM), being more potent than ergosterol peroxide. Further cellular mechanism studies in HepG2 cells indicated that compound 7j triggered the mitochondrial-mediated apoptosis by decreasing mitochondrial membrane potential (MMP), which was associated with up-regulation of Bax, down-regulation of Bcl-2, activation levels of the caspase cascade, and formation of reactive oxygen species (ROS). The above findings indicated that compound 7j may be used as a promising skeleton for antitumor agents with improved efficacy.


Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Semicarbazones/chemistry , Steroids/chemistry , Antineoplastic Agents/chemistry , Apoptosis/physiology , Caspases/metabolism , Cell Line, Tumor , Drug Design , Drug Screening Assays, Antitumor , Hep G2 Cells , Humans , Membrane Potential, Mitochondrial/drug effects , Oxidative Stress/drug effects , Peroxides/chemistry , Proto-Oncogene Proteins c-bcl-2/metabolism , Semicarbazones/chemical synthesis , Semicarbazones/pharmacology , Thiosemicarbazones/chemical synthesis , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology , bcl-2-Associated X Protein/metabolism
7.
Bioorg Med Chem Lett ; 29(23): 126726, 2019 12 01.
Article in English | MEDLINE | ID: mdl-31615700

ABSTRACT

A series of novel 2,3-dihydro-4H-1-benzoselenin-4-one (thio)semicarbazone derivatives were designed and synthesized by using molecular hybridization approach. All the target compounds were characterized by HRMS and NMR and evaluated in vitro antifungal activity against five pathogenic strains. In comparison with precursor selenochroman-4-ones, the hybrid molecules in this study showed significant improvement in antifungal activities. Notably, compound B8 showed significant antifungal activity against other strains excluding Aspergillus fumigatus (0.25 µg/mL on Candida albicans, 2 µg/mL on Cryptococcus neoformans, 8 µg/mL on Candida zeylanoides and 2 µg/mL on fluconazole-sensitive strains of Candida albicans). Moreover, compounds B8, B9 and C2 also displayed most potent activities against four fluconazole-resistance strains. Especially the MIC values of the hybrid molecule B8 against fluconazole-resistant strains were in the range of 0.5-2 µg/mL. Therefore, the molecular hybridization approach in this study provided new ideas for the development of antifungal drug.


Subject(s)
Antifungal Agents/therapeutic use , Aspergillus fumigatus/drug effects , Candida albicans/drug effects , Cryptococcus neoformans/drug effects , Semicarbazones/chemical synthesis , Antifungal Agents/pharmacology , Molecular Structure , Semicarbazones/chemistry , Structure-Activity Relationship
8.
Steroids ; 148: 36-46, 2019 08.
Article in English | MEDLINE | ID: mdl-31075341

ABSTRACT

Eleven new steroidal mono- and bis(semicarbazones) 2a-e, 4d and 3a-e have been prepared starting from various 3-oxo-α,ß-unsaturated steroids. Mono-semicarbazones 2a-e were further subjected to ethyl chloroacetate in boiling absolute ethanol but, instead of expected intramolecular cyclocondensation reaction products, the new carbazate esters 5a-e were obtained. The structures of all synthesized compounds and identification of each E/Z isomer were deduced by elemental analysis, HRMS, NMR, and IR spectroscopy. Preliminary screening for the cytotoxic activity in vitro of the new compounds has been conducted against three cancer cell lines, K562, Jurkat and HeLa cells. HeLa cells were the most sensitive while K562 cells were the least sensitive to the cytotoxic action of the novel steroid derivatives. Compounds 2e, 3c and 5e were found to have the best but still moderate cytotoxic effects. All tested compounds showed very weak antimicrobial activities. These results demonstrate that the replacement of thioxo group with carbonyl group in steroidal hydrazone derivatives resulted in decrease in their biological activity.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Antineoplastic Agents/pharmacology , Semicarbazones/pharmacology , Steroids/pharmacology , Animals , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Artemia/drug effects , Aspergillus/drug effects , Cell Proliferation/drug effects , Clostridium/drug effects , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Drug Screening Assays, Antitumor , HeLa Cells , Humans , Jurkat Cells , K562 Cells , Microbial Sensitivity Tests , Molecular Conformation , Pseudomonas aeruginosa/drug effects , Semicarbazones/chemical synthesis , Semicarbazones/chemistry , Stereoisomerism , Steroids/chemical synthesis , Steroids/chemistry , Structure-Activity Relationship
9.
Molecules ; 24(1)2019 Jan 07.
Article in English | MEDLINE | ID: mdl-30621111

ABSTRACT

During the last three decades the extent of life-threatening fungal infections has increased remarkably worldwide. Synthesis and structure elucidation of certain imidazole-semicarbazone conjugates 5a⁻o are reported. Single crystal X-ray analysis of compound 5e unequivocally confirmed its assigned chemical structure and the (E)-configuration of its imine double bond. Compound 5e crystallized in the triclinic system, P-1, a = 6.3561 (3) Å, b = 12.5095 (8) Å, c = 14.5411 (9) Å, α = 67.073 (4)°, ß = 79.989 (4)°, γ =84.370 (4)°, V = 1048.05 (11) ų, Z = 2. In addition, DIZ and MIC assays were used to examine the in vitro antifungal activity of the title conjugates 5a⁻o against four fungal strains. Compound 5e, bearing a 4-ethoxyphenyl fragment, showed the best MIC value (0.304 µmol/mL) against both C. tropicalis and C. parapsilosis species, while compounds 5c (MIC = 0.311 µmol/mL), 5k, and 5l (MIC = 0.287 µmol/mL) exhibited the best anti-C. albicans activity.


Subject(s)
Antifungal Agents/chemistry , Benzodioxoles/chemistry , Imidazoles/chemistry , Semicarbazones/chemistry , Antifungal Agents/chemical synthesis , Antifungal Agents/pharmacology , Benzodioxoles/chemical synthesis , Benzodioxoles/pharmacology , Candida albicans/drug effects , Candida albicans/pathogenicity , Humans , Imidazoles/chemical synthesis , Imidazoles/pharmacology , Microbial Sensitivity Tests , Molecular Structure , Semicarbazones/chemical synthesis , Semicarbazones/pharmacology , Spectrum Analysis , Structure-Activity Relationship
10.
Bioorg Chem ; 82: 211-223, 2019 02.
Article in English | MEDLINE | ID: mdl-30326403

ABSTRACT

Based on the quantitative structure-activity relationship (QSAR), some novel p-aminobenzoic acid derivatives as promising cholinesterase enzyme inhibitors were designed, synthesized, characterized and evaluated to enhance learning and memory. The in vitro enzyme kinetic study of the synthesized compounds revealed the type of inhibition on the respective acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The in vivo studies of the synthesized compounds exhibited significant reversal of cognitive deficits in the animal models of amnesia as compared to standard drug donepezil. Further, the ex vivo studies in the specific brain regions like the hippocampus, hypothalamus, and prefrontal cortex regions also exhibited AChE inhibition comparable to standard donepezil. The in silico molecular docking and dynamics simulations studies of the most potent compound 22 revealed the consensual interactions at the active site pocket of the AChE.


Subject(s)
Alzheimer Disease/drug therapy , Cholinesterase Inhibitors/therapeutic use , Nootropic Agents/therapeutic use , para-Aminobenzoates/therapeutic use , Acetylcholinesterase/chemistry , Acetylcholinesterase/metabolism , Animals , Brain/metabolism , Butyrylcholinesterase/chemistry , Butyrylcholinesterase/metabolism , Catalytic Domain , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/toxicity , Drug Design , Female , Kinetics , Male , Memory/drug effects , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Structure , Nootropic Agents/chemical synthesis , Nootropic Agents/chemistry , Nootropic Agents/toxicity , Quantitative Structure-Activity Relationship , Rats , Semicarbazones/chemical synthesis , Semicarbazones/chemistry , Semicarbazones/therapeutic use , Semicarbazones/toxicity , para-Aminobenzoates/chemical synthesis , para-Aminobenzoates/chemistry , para-Aminobenzoates/toxicity
11.
Mol Biol Rep ; 46(1): 679-686, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30511302

ABSTRACT

A new series of semicarbazone-triazole hybrid derivatives have been synthesized by condensation between heterocyclic aldehydes and the commercial semicarbazide hydrochloride. The in vitro antioxidant activity of these species was tested using 1,1-diphenyl-2-picrylhydrazyl radical, 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and Ferric reducing antioxidant power assays and their antimicrobial activity against different microbial strains was carried out. Furthermore, molecular properties prediction and drug likeness were also determinated using Molinspiration. Among such derivatives, compounds (E)-2-(4-((1-(2,6-dimethylphenyl)-1H-1,2,3-triazol-4-yl)methoxy)benzylidene)hydrazine carboxamide (4c), and (E)-2-(4-((1-(2-methoxyphenyl)-1-H-1,2,3-triazol-4-yl)methoxy)benzylidene)hydrazine-carboxamide (4e) exhibit excellent scavenging ability, especially with IC50 = 1.57 ± 1.66 mg/mL (4c) and IC50 = 1.82 ± 0.15 mg/mL (4e) with 1,1-diphenyl-2-picrylhydrazyl radical and IC50 = 1.90 ± 1.33 mg/mL (4c) with 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) as compared to the standards butylhydroxytoluene (IC50 = 1.60 ± 1.98 mg/mL) and Trolox (IC50 = 1.45 ± 1.33 mg/mL), respectively. The antimicrobial assay results, show that compounds 4c and 4e highlighted the most interesting profile with the potent activity was obtained against S. enteritidis (1.56-fold) and then M. luteus (1.45-fold) which are significantly higher than the positive control, chloramphenicol. By the other hand, the synthesized semicarbazone derivatives met the Lipinski's rule criteria by presenting good drug likeness and bioactivity scores. The structure-property-activity relationships have been carried out in order to determine the effect of various substituents on the molecular and the biological properties. All these investigations confirm that our synthetic semicarbazone can be explored for generating new potential drug with good oral bioavailability.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Antioxidants/pharmacology , Semicarbazones/chemical synthesis , Semicarbazones/pharmacology , Triazoles/chemical synthesis , Triazoles/pharmacology , Anti-Bacterial Agents/chemical synthesis , Antifungal Agents/chemical synthesis , Bacteria/drug effects , Biphenyl Compounds/chemistry , Free Radical Scavengers/pharmacology , Fungi/drug effects , Microbial Sensitivity Tests , Picrates/chemistry , Software , Structure-Activity Relationship
12.
Bioorg Chem ; 82: 6-16, 2019 02.
Article in English | MEDLINE | ID: mdl-30267972

ABSTRACT

Urease is a bacterial enzyme that is responsible for virulence of various pathogenic bacteria such as Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumoniae, Ureaplasma urealyticum, Helicobacter pylori and Mycobacterium tuberculosis. Increased urease activity aids in survival and colonization of pathogenic bacteria causing several disorders especially gastric ulceration. Hence, urease inhibitors are used for treatment of such diseases. In search of new molecules with better urease inhibitory activity, herein we report a series of acridine derived (thio)semicarbazones (4a-4e, 6a-6l) that were found to be active against urease enzyme. Molecular docking studies were carried out to better comprehend the preferential mode of binding of these compounds against urease enzyme. Docking against urease from pathogenic bacterium S. pasteurii was also carried out with favorable results. In silico ADME evaluation was done to determine drug likeness of synthesized compounds.


Subject(s)
Acridines/chemistry , Enzyme Inhibitors/chemistry , Hydrazones/chemistry , Semicarbazones/chemistry , Urease/antagonists & inhibitors , Acridines/chemical synthesis , Acridines/pharmacokinetics , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacokinetics , Catalytic Domain , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Hydrazones/chemical synthesis , Hydrazones/pharmacokinetics , Molecular Docking Simulation , Molecular Structure , Semicarbazones/chemical synthesis , Semicarbazones/pharmacokinetics , Sporosarcina/enzymology , Structure-Activity Relationship , Urease/chemistry
13.
Med Chem ; 15(3): 240-256, 2019.
Article in English | MEDLINE | ID: mdl-30332972

ABSTRACT

BACKGROUND: Chagas disease, also known as American trypanosomiasis, is classified as one of the 17 most important neglected diseases by the World Health Organization. The only drugs with proven efficacy against Chagas disease are benznidazole and nifurtimox, however both show adverse effects, poor clinical efficacy, and development of resistance. For these reasons, the search for new effective chemical entities is a challenge to research groups and the pharmaceutical industry. OBJECTIVE: Synthesis and evaluation of antitrypanosomal activities of a series of thiosemicarbazones and semicarbazones containing 1,2,3-1H triazole isatin scaffold. METHOD: 5'-(4-alkyl/aryl)-1H-1,2,3-triazole-isatins were prepared by Huisgen 1,3-dipolar cycloaddition and the thiosemicarbazones and semicarbazones were obtained by the 1:1 reactions of the carbonylated derivatives with thiosemicarbazide and semicarbazide hydrochloride, respectively, in methanol, using conventional reflux or microwave heating. The compounds were assayed for in vitro trypanocidal activity against Trypanosoma cruzi, the aetiological agent of Chagas disease. Beyond the thio/semicarbazone derivatives, isatin and triazole synthetic intermediates were also evaluated for comparison. RESULTS: A series of compounds were prepared in good yields. Among the 37 compounds evaluated, 18 were found to be active, in particular thiosemicarbazones containing a non-polar saturated alkyl chain (IC50 = 24.1, 38.6, and 83.2 µM; SI = 11.6, 11.8, and 14.0, respectively). To further elucidate the mechanism of action of these new compounds, the redox behaviour of some active and inactive derivatives was studied by cyclic voltammetry. Molecular docking studies were also performed in two validated protein targets of Trypanosoma cruzi, i.e., cruzipain (CRZ) and phosphodiesterase C (TcrPDEC). CONCLUSION: A class of thio/semicarbazones structurally simple and easily accessible was synthesized. Compounds containing thiosemicarbazone moieties showed the best results in the series, being more active than the corresponding semicarbazones. Our results indicated that the activity of these compounds does not originate from an oxidation-reduction pathway but probably from the interactions with trypanosomal enzymes.


Subject(s)
Cell Survival/drug effects , Electrochemical Techniques/methods , Semicarbazones/chemical synthesis , Semicarbazones/pharmacology , Spectrum Analysis/methods , Thiosemicarbazones/chemical synthesis , Thiosemicarbazones/pharmacology , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/pharmacology , Animals , Cell Line , Mice , Molecular Docking Simulation , Semicarbazones/chemistry , Structure-Activity Relationship , Thiosemicarbazones/chemistry , Trypanocidal Agents/chemistry , Trypanosoma cruzi/drug effects
14.
Bioorg Chem ; 79: 19-26, 2018 09.
Article in English | MEDLINE | ID: mdl-29709568

ABSTRACT

A series of hydrazinecarboxamide derivatives were synthesized and examined against urease for their inhibitory activity. Among the series, the 1-(3-fluorobenzylidene)semicarbazide (4a) (IC50 = 0.52 ±â€¯0.45 µM), 4u (IC50 = 1.23 ±â€¯0.32 µM) and 4h (IC50 = 2.22 ±â€¯0.32 µM) were found most potent. Furthermore, the molecular docking study was also performed to demonstrate the binding mode of the active hydrazinecarboxamide with the enzyme, urease. In order to estimate drug likeness of compounds, in silico ADME evaluation was carried out. All compounds exhibited favorable ADME profiles with good predicted oral bioavailability.


Subject(s)
Enzyme Inhibitors/chemistry , Semicarbazones/chemistry , Urease/antagonists & inhibitors , Canavalia/enzymology , Catalytic Domain , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Molecular Docking Simulation , Molecular Structure , Semicarbazones/chemical synthesis , Semicarbazones/pharmacokinetics , Structure-Activity Relationship , Urease/chemistry
15.
J Biomol Struct Dyn ; 36(15): 4099-4113, 2018 11.
Article in English | MEDLINE | ID: mdl-29198175

ABSTRACT

Two new compounds (E)-2-(5,7-dibromo-3,3-dimethyl-3,4-dihydroacridin-1(2H)-ylidene)hydrazinecarbothiomide (3) and (E)-2-(5,7-dibromo-3,3-dimethyl-3,4-dhihydroacridin-1(2H)-ylidene)hydrazinecarboxamide (4) were synthesized and evaluated for their anticholinesterase activities. In vitro tests performed by NMR and Ellman's tests, pointed to a mixed kinetic mechanism for the inhibition of acetylcholinesterase (AChE). This result was corroborated through further docking and molecular dynamics studies, suggesting that the new compounds can work as gorge-spanning ligands by interacting with two different binding sites inside AChE. Also, in silico toxicity evaluation suggested that these new compounds can be less toxic than tacrine.


Subject(s)
Acetylcholinesterase/chemistry , Molecular Dynamics Simulation , Nootropic Agents/chemical synthesis , Semicarbazones/chemical synthesis , Alzheimer Disease/drug therapy , Alzheimer Disease/enzymology , Alzheimer Disease/physiopathology , Catalytic Domain , Drug Design , Enzyme Assays , Gene Expression , Humans , Hydrogen Bonding , Kinetics , Ligands , Molecular Docking Simulation , Nootropic Agents/pharmacology , Protein Binding , Protein Interaction Domains and Motifs , Protein Structure, Secondary , Semicarbazones/pharmacology , Tacrine/pharmacology , Thermodynamics
16.
J Enzyme Inhib Med Chem ; 33(1): 37-57, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29098902

ABSTRACT

A series of 2-amino-5-nitrothiazole derived semicarbazones were designed, synthesised and investigated for MAO and ChE inhibition properties. Most of the compounds showed preferential inhibition towards MAO-B. Compound 4, (1-(1-(4-Bromophenyl)ethylidene)-4-(5-nitrothiazol-2-yl)semicarbazide) emerged as lead candidate (IC50 = 0.212 µM, SI = 331.04) against MAO-B; whereas compounds 21 1-(5-Bromo-2-oxoindolin-3-ylidene)-4-(5-nitrothiazol-2-yl)semicarbazide (IC50 = 0.264 µM) and 17 1-((4-Chlorophenyl) (phenyl)methylene)-4-(5-nitrothiazol-2-yl)semicarbazide (IC50 = 0.024 µM) emerged as lead AChE and BuChE inhibitors respectively; with activity of compound 21 almost equivalent to tacrine. Kinetic studies indicated that compound 4 exhibited competitive and reversible MAO-B inhibition while compounds 21 and 17 showed mixed-type of AChE and BuChE inhibition respectively. Docking studies revealed that these compounds were well-accommodated within MAO-B and ChE active sites through stable hydrogen bonding and/or hydrophobic interactions. This study revealed the requirement of small heteroaryl ring at amino terminal of semicarbazone template for preferential inhibition and selectivity towards MAO-B. Our results suggest that 5-nitrothiazole derived semicarbazones could be further exploited for its multi-targeted role in development of anti-neurodegenerative agents. [Formula: see text] A library of 2-amino-5-nitrothiazole derived semicarbazones (4-21) was designed, synthesised and evaluated for in vitro MAO and ChE inhibitory activity. Compounds 4, 21 and 17 (shown) have emerged as lead MAO-B (IC50:0.212 µM, competitive and reversible), AChE (IC50:0.264 µM, mixed and reversible) and BuChE (IC50:0.024 µM, mixed and reversible) inhibitor respectively. SAR studies disclosed several structural aspects significant for potency and selectivity and indicated the role of size of aryl binding site in potency and selectivity towards MAO-B. Antioxidant activity and neurotoxicity screening results further suggested their multifunctional potential for the therapy of neurodegenerative diseases.


Subject(s)
Cholinesterase Inhibitors/pharmacology , Drug Design , Monoamine Oxidase Inhibitors/pharmacology , Semicarbazones/pharmacology , Thiazoles/pharmacology , Acetylcholinesterase/metabolism , Animals , Binding Sites/drug effects , Brain/enzymology , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/chemistry , Dose-Response Relationship, Drug , Mitochondria/drug effects , Mitochondria/metabolism , Molecular Structure , Monoamine Oxidase/metabolism , Monoamine Oxidase Inhibitors/chemical synthesis , Monoamine Oxidase Inhibitors/chemistry , Particle Size , Rats , Rats, Wistar , Semicarbazones/chemical synthesis , Semicarbazones/chemistry , Structure-Activity Relationship , Thiazoles/chemistry
17.
Inorg Chem ; 56(16): 9725-9741, 2017 Aug 21.
Article in English | MEDLINE | ID: mdl-28766938

ABSTRACT

This research aimed to develop new tumor targeted theranostic agents taking advantage of the similarities in coordination chemistry between technetium and rhenium. A γ-emitting radioactive isotope of technetium is commonly used in diagnostic imaging, and there are two ß- emitting radioactive isotopes of rhenium that have the potential to be of use in radiotherapy. Variants of the 6-hydrazinonicotinamide (HYNIC) bifunctional ligands have been prepared by appending thioamide functional groups to 6-hydrazinonicotinamide to form pyridylthiosemicarbazide ligands (SHYNIC). The new bidentate ligands were conjugated to the tumor targeting peptides Tyr3-octreotate and cyclic-RGD. The new ligands and conjugates were used to prepare well-defined {M═O}3+ complexes (where M = 99mTc or natRe or 188Re) that feature two targeting peptides attached to the single metal ion. These new SHYNIC ligands are capable of forming well-defined rhenium and technetium complexes and offer the possibility of using the 99mTc imaging and 188/186Re therapeutic matched pairs.


Subject(s)
Coordination Complexes/chemical synthesis , Peptides, Cyclic/chemical synthesis , Rhenium/chemistry , Semicarbazones/chemical synthesis , Coordination Complexes/chemistry , Drug Stability , Hydrazines/chemistry , Ligands , Peptides, Cyclic/chemistry , Pyridines/chemistry , Semicarbazones/chemistry , Theranostic Nanomedicine , Thioamides/chemistry
18.
Chembiochem ; 18(15): 1502-1509, 2017 08 04.
Article in English | MEDLINE | ID: mdl-28440961

ABSTRACT

Zinc-complexing ligands are prospective anti-biofilm agents because of the pivotal role of zinc in the formation of Staphylococcus aureus biofilm. Accordingly, the potential of a thiosemicarbazone (compound C1) and a benzothiazole-based ligand (compound C4) in the prevention of S. aureus biofilm formation was assessed. Compound C1 displayed a bimodal activity, hindering biofilm formation only at low concentrations and promoting biofilm growth at higher concentrations. In the case of C4, a dose-dependent inhibition of S. aureus biofilm growth was observed. Atomic force microscopy analysis suggested that at higher concentrations C1 formed globular aggregates, which perhaps formed a substratum that favored adhesion of cells and biofilm formation. In the case of C4, zinc supplementation experiments validated zinc complexation as a plausible mechanism of inhibition of S. aureus biofilm. Interestingly, C4 was nontoxic to cultured HeLa cells and thus has promise as a therapeutic anti-biofilm agent. The essential understanding of the structure-driven implications of zinc-complexing ligands acquired in this study might assist future screening regimes for identification of potent anti-biofilm agents.


Subject(s)
Benzothiazoles/pharmacology , Biofilms/drug effects , Chelating Agents/pharmacology , Semicarbazones/pharmacology , Staphylococcus aureus/drug effects , Zinc/chemistry , Benzothiazoles/chemical synthesis , Benzothiazoles/toxicity , Chelating Agents/chemical synthesis , Chelating Agents/toxicity , Edetic Acid/pharmacology , Edetic Acid/toxicity , HeLa Cells , Humans , Microscopy, Fluorescence , Semicarbazones/chemical synthesis , Semicarbazones/toxicity
19.
J Inorg Biochem ; 162: 295-308, 2016 09.
Article in English | MEDLINE | ID: mdl-27138101

ABSTRACT

Substituted semicarbazones/thiosemicarbazones and their copper complexes have been prepared and several single crystal structures examined. The copper complexes of these semicarbazone/thiosemicarbazones were prepared and several crystal structures examined. The single crystal X-ray structure of the pyridyl-substituted semicarbazone showed two types of copper complexes, a monomer and a dimer. We also found that the p-nitrophenyl semicarbazone formed a conventional 'magic lantern' acetate-bridged dimer. Electron Paramagnetic Resonance (EPR) of several of the copper complexes was consistent with the results of single crystal X-ray crystallography. The EPR spectra of the p-nitrophenyl semicarbazone copper complex in dimethylsulfoxide (DMSO) showed the presence of two species, confirming the structural information. Since thiosemicarbazones and semicarbazones have been reported to exhibit anticancer activity, we examined the anticancer activity of several of the derivatives reported in the present study and interestingly only the thiosemicarbazone showed activity while the semicarbazones were not active indicating that introduction of sulphur atom alters the biological profile of these thiosemicarbazones.


Subject(s)
Antineoplastic Agents/chemical synthesis , Coordination Complexes/chemical synthesis , Copper/chemistry , Semicarbazones/chemical synthesis , Thiosemicarbazones/chemical synthesis , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Coordination Complexes/pharmacology , Crystallography, X-Ray , Dimerization , Dimethyl Sulfoxide/chemistry , Electron Spin Resonance Spectroscopy , Epithelial Cells , Humans , Inhibitory Concentration 50 , Molecular Structure , Semicarbazones/pharmacology , Solvents/chemistry , Structure-Activity Relationship , Sulfur/chemistry , Thiosemicarbazones/pharmacology
20.
ChemMedChem ; 11(11): 1145-60, 2016 06 06.
Article in English | MEDLINE | ID: mdl-27135466

ABSTRACT

A library of 3,4-(methylenedioxy)aniline-derived semicarbazones was designed, synthesized, and evaluated as monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitors for the treatment of neurodegenerative diseases. Most of the new compounds selectively inhibited MAO-B and AChE, with IC50 values in the micro- or nanomolar ranges. Compound 16, 1-(2,6-dichlorobenzylidene)-4-(benzo[1,3]dioxol-5-yl)semicarbazide presented a balanced multifunctional profile of MAO-A (IC50 =4.52±0.032 µm), MAO-B (IC50 =0.059±0.002 µm), and AChE (IC50 =0.0087±0.0002 µm) inhibition without neurotoxicity. Kinetic studies revealed that compound 16 exhibits competitive and reversible inhibition against MAO-A and MAO-B, and mixed-type inhibition against AChE. Molecular docking studies further revealed insight into the possible interactions within the enzyme-inhibitor complexes. The most active compounds were found to interact with the enzymes through hydrogen bonding and hydrophobic interactions. Additionally, in silico molecular properties and ADME properties of the synthesized compounds were calculated to explore their drug-like characteristics.


Subject(s)
Acetylcholinesterase/metabolism , Cholinesterase Inhibitors/chemical synthesis , Drug Design , Monoamine Oxidase Inhibitors/chemical synthesis , Monoamine Oxidase/metabolism , Semicarbazones/metabolism , Acetylcholinesterase/chemistry , Aniline Compounds/chemistry , Animals , Brain/drug effects , Brain/metabolism , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacology , Drug Evaluation, Preclinical , Enzyme Activation/drug effects , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions , Inhibitory Concentration 50 , Male , Mice , Molecular Docking Simulation , Monoamine Oxidase/chemistry , Monoamine Oxidase Inhibitors/pharmacology , Protein Binding/drug effects , Protein Structure, Tertiary , Rats , Rats, Wistar , Semicarbazones/chemical synthesis , Semicarbazones/chemistry , Structure-Activity Relationship
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