KBrO_3/MoO_3:An efficient reagent system for the oxidative deprotection of semicarbazones,1,1-diacetates and acetals

Semicarbazones, 1,1-diacetates and acetals are efficiently converted to their corresponding carbonyl compounds using synergistic effect between KBrO3 and MoO3 in refluxing CH3CN-H2O in good to high yields.

Microwave-assisted synthesis,anticonvulsant activity and quantum mechanical modelling of N-(4-bromo-3-methylphenyl) semicarbazones

Objective: To study the effect of halo substitution on disubstituted aryl semicarbazones on the anticonvulsant potential and model the activity based on quantum mechanics. Methods: A series of twenty-six compounds of N4-(4-bromo-3-methylphenyl) semicarbazones were synthesized and evaluated for the anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure threshold tests. Some potential compounds were also tested in the subcutaneous strychnine (scSTY) and subcutaneous picrotoxin (scPIC) seizure threshold tests. The synthesized compounds were tested for behavioral impairment and CNS (central nervous system) depression in mice. Quantum mechanical modelling was carried out on these compounds to gain understanding on the structural features essential for activity. Results: Some compounds possessed broad spectrum anticonvulsant activity as indicated by their effect in pentylenetetrazole, strychnine, picrotoxin and maximal electro- shock seizures models in resemblance to other aryl semicarbazone derivatives reported earlier. The higher the difference in HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels was, the greater was the activity profile. Conclusion: The pharmacophoric requirements for compounds to exhibit anticonvulsant activity that includes one aryl unit in proximity to a hydrogen donor-acceptor domain and an electron donor have been justified with the molecular orbital surface analysis of the synthesized compounds.

Intramolecular cyclization of steroidal semicarbazones to pyrazoles using Vilsmeier reagent

The preparation of hitherto unknown steroidal heterocycles containing pyrazole fused to 6,7-position of the steroidal nucleus is described. These heterocycles were prepared by the action of Vilsmeier reagent with steroidal semicarbazones in DMF. The structure of the compounds has been established on the basis of their elemental analysis and spectral data. A general mechanistic scheme for these reactions is also suggested based on current and previous results.

Synthesis and evaluation of 4-substituted semicarbazones of levulinic acid for anticonvulsant activity

Objective: A series of 4-aryl substituted semicarbazones of levulinic acid (4-oxo pentanoic acid) was designed and synthesized to meet the structural requirements essential for anticonvulsant activity. Methods: All the compounds were evaluated for anticonvulsant activity. Anticonvulsant activity was determined after intraperitoneal (i.p.) administration to mice by maximal electroshock (MES) and subcutaneous metrazol (ScMet) induced seizure methods and minimal motor impairment was determined by rotorod test. Results: A majority of the compounds exhibited significant anticonvulsant activity after intraperitoneal administration. In the present study 4-(4'-fluoro phenyl) levulinic acid semicarbazone emerged as the most active molecule, showing broad spectrum of activity with low neurotoxicity. Unsubstituted levulinic acid semicarbazone was found to be inactive in all the screens. Conclusion: The results obtained validate the hypothesis that presence of an aryl group near the semicarbazone moiety is essential for anticonvulsant activity. The results also indicate that the hydrophilic-hydrophobic site can accommodate hydrophilic groups.

Synthesis and Crystal Structure ofp-tert-Butylcalix[4]arene 1,3-Distal and Monosubstituted Semicarbazones and Thiosemicarbazones

A series of p-tert-butylcalix[4]arene 1,3-distal and monosubstituted semicarbazones and thiosemicarbazones was preparedd by acid catalyzed condensation reaction of active calixarene aldehydes with semi- carbazide and thiocarbazide in methanol. One representative single crystal was determined by X-ray dirraction method, which shows that calixarene exists in cone configuration and intramolecular hydrogen-bands exist in the crystal.

A novel series of 2,5-disubstituted 1,3,4-thiadiazoles as potential anticonvulsant agent

In pursuit for better antiepileptic drug and the importance of semicarbazones and 2,5-disubstituted 1,3,4-thiadiazoles as anticonvulsant pharmacophore, a series of novel N-（{5-[（6-methyl-l-benzofuran-3-yl）methyl]-l,3,4-thiadiazol-2-yl}carba- mothioyl）-2/3/4-substitutedbenzamide were designed, synthesized and evaluated for their anticonvulsant activity. The findings of the present studies confirmed that the pharmacophore model with four binding sites is crucial for anticonvulsant activity. Structure-activity relationships among synthesized compounds were also established.

Synthesis and Crystal Structure of a Zinc(II) Complex Salt with the Schiff Base of Picolinaldehyde N-oxide and Semicarbazone

The title zinc（Ⅱ） complex salt [Zn（H2O）6]（ClO4）2-（PNOS）4, where PNOS is derived from picolinaldehyde N-oxide with semicarbazone, has been prepared and structurally characterized by X-ray single-crystal analysis. It crystallizes in triclinic, space group PI with a = 7.529（3）, b = 10.206（4）, c = 14.678（6）A, a = 86.293（6）, β= 87.686（7）, γ= 81.382（6）°, C28H44Cl2N16O22Zn, Mr = 1093.06, V = 1112.3（8） ,A^3 Z = 1, Dc = 1.632 g/cm^3, S = 1.089, μ（MoKa） = 0.773 mm^-1, F（000） = 564, the final R = 0.0438 and wR = 0.1076 for 3888 independent reflections with Rint = 0.0224. The crystal structure possesses a [Zn（H2O）6]^2＋ cation, two ClO4^- anions and four PNOSs. In the crystal structure, Zn^2＋ cation is located at the symcenter and coordinated by six water molecules. In [Zn（H2O）6]^2＋, an elongate octahedral complex cation, the average Zn-O bond length is 2.087（2） A. There exist a lot of H bonds in the structure, linking the cation [Zn（H2O）6]^2＋, anion ClO4^- and PNOS to form a 3D network.

Hepatoprotective effect of acetone semicarbazone on Ehrlich ascites carcinoma induced carcinogenesis in experimental mice

Objective:To determine the hepatoprotective effect of acetone semicarbazone(ASC)in vivo in normal and Ehrlich ascites carcinoma(EAC)bearing male Swiss albino mice.Methods:Druginduced changes in biochemical and behavioral parameters at dose of 2.0 mg/kg body weight for14 d and nullifying the toxicity induced by EAC cells were studied.The histopathology studies of the protective effects of ASC on vital organs were also assessed.Results:The administration of ASC made insignificant changes in body weight and behavioral(salivation,diarrhea,muscular numbness)changes during treatment period due to minor toxicity were minimized after the treatment in normal mice.The biochemical parameters,including serum glutamate pyruvate transaminase,glutamate oxaloactate transaminase,alkaline phosphatase,serum glucose,cholesterol,urea,triglyceride and billirubin changed modestly in normal mice receiving ASC.Though the treatment continued,these values gradually decreased to normal level after the treatment.In EAC bearing mice,the toxic effects due to EAC cells in all cases were nullified by treatment with the ASC.Significant abnormalities were not detected in histology of the various organs of the normal mice treated with ASC.Conclusions:ASC can,therefore,be considered safe in formulating novel anticancer drug,as it exhibits strong protective effect against EAC cell bearing mice.

Synthesis,Crystal Structure and Interaction with DNA of a Novel Chromium(Ⅲ) Complex Containing Salicylaldehyde Semicarbazone

The novel chromium（Ⅲ） complex with salicylaldehyde semicarbazone was synthesized and characterized by IR spectra and single-crystal X-ray diffraction analysis. The crystal belongs to the orthorhombic system, space group Pbca with a = 8.9849（13）, b = 12.0475（16）, c = 34.522（5）A, V = 3736.9（9）A3, Z = 8, C16H18C1CrN6O5, Mr= 461.81, De= 1.642 g/cm^3, F（000） = 1896,A（MoKα） = 0.799 mm^-1, the final R = 0.0370 and wR = 0.0827 for 2908 observed reflections with I 〉 2σ（I）. The interaction between the chromium（Ⅲ） complex with calf thymus DNA （Ct-DNA） has been investigated by absorption spectroscopy, fluorescence spectroscopy and viscosity measurements. The results indicated that the complex was bonded to Ct-DNA through a non-classical intercalative mode.

Crystal and Molecular Structure of 4-Phenyl-cyclohexanone Semicarbazone

C13H17N3O,Mr=231.30,monoclinic,P21/,a=7.094(5).b =32.14(l),c=5.894(4)A,β=112.84(4)°,Z=4,Dx=l.24 gcm-3,V=1238(l) A 3,λ(MoKα)=0.71069 A,μ=0.76 cm-1.F(000)=496,T=293K,R=0.060,Rω=0.062 for 1205 reflections(I】3σ(I)).The cyclohexane ring shows a slightly distorted chair conformation.The NHCONH2 group has a conformation with the C=O bond trans to the N-N bond.The molecules in the crystal are linked together by the O…H-N hydrogen bonding.forming an infinite ribbon.

In vivo Anticancer Activities of Benzophenone Semicarbazone against Ehrlich Ascites Carcinoma Cells in Swiss Albino Mice

Objective Benzophenone semicarbazone(BSC) was synthesized and characterized to identify compounds with anticancer activities. Methods Anticancer activities were studied against Ehrlich Ascites Carcinoma(EAC) cells in Swiss albino mice by monitoring parameters such as tumor weight measurement,survival time of tumor bearing mice,tumor cell growth inhibition,and so on.Some hematological parameters,such as red blood cells,white blood cells,and hemoglobin content,were also measured. Results The results showed that BSC has a positive effect against EAC cells.An assessment was conducted by comparing these results with those obtained using the standard drug bleomycin. Conclusions The BSC compound can be considered as a potent anticancer agent.

Synthesis, Spectral Characterization and Crystal Structure of 2-((3-Aminophenyl)(phenyl)methylene) hydrazinecarboxamide

A benzophenone substituted semicarbazone, 2-((3-aminophenyl)(phenyl)methylene)hydrazinecarboxamide (APHC) had been synthesized in good yield by the condensation of 3-aminobenzophenone and semicarbazide hydrochloride. The title compound was elucidated by elemental analysis (CHN), FTIR, 1H and 13C-NMR, 1H-1H COSY, TGA and single crystal X-ray diffraction. The compound crystallized in the orthorhombic crystal system with space group of Pccn, Z = 32, V = 10375.1 (2) ?3, and lattice constants a = 12.3855 (1) ?, b = 34.5746 (5) ?, c = 24.2283 (3) ??and γ = β = α = 90°. The molecular view shows that APHC contains four molecules of each species in the asymmetric unit, with similar geometries. However, there is no intramolecular hydrogen bond found in the crystal structure of the synthesized compound. X-ray diffraction also reveals that the molecule of the semicarbazone exists as a Z isomer with respect to the C=N.

Design, Synthesis and Biological Evaluation of Novel Benzothiazole Derivatives Bearing Semicarbazone Moiety as Antitumor Agents

A series of novel benzothiazole derivatives bearing semicarbazone as a linker was designed and synthe- sized, and their in vitro antitumor activities were evaluated against four cancer cell lines（HT29, H460, A549 and MDA-MB-231）. Most of them showed moderate to excellent activity against all the tested cell lines. Among them, compounds 12a--12i with fluoro-substituted benzyl-1H-indole moiety displayed more potent activity than those with phenyl moiety. The most promising compound 12d exhibited excellent antitumor activity with IC50 values of 0.015, 0.28, 1.53 and 0.68 p.mol/L against the four tested cell lines respectively.

Synthesis and characterization of semicarbazone metal complexes of Sn(IV) and Zr(IV)

Three semicarbazonyl ligands were synthesized and used to form six novel organometallic complexes with Ph2SnCl2 and Cp2ZrCl2. All these complexes were characterized by IR 1H NMR MS and elemental analysis.