Synthesis, Spectral, and In Vitro Antibacterial Studies of Organosilicon(IV) Complexes with Schiff Bases Derived from Amino Acids.

PubMed

Singh, Har Lal; Singh, Jangbhadur; Mukherjee, A

2013-01-01

The present work stems from our interest in the synthesis, characterization, and antibacterial evaluation of organosilicon(IV) complexes of a class of amino-acid-based Schiff base which have been prepared by the interaction of ethoxytrimethylsilane with the Schiff bases (N OH) in 1 : 1 molar ratio. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including electronic IR and NMR ((1)H, (13)C, and (29)Si) spectroscopy. The analytical and spectral data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated for in vitro antimicrobial activity against bacteria (Bacillus cereus, Nocardia spp., E. aerogenes, Escherichia coli, Klebsiella spp., and Staphylococcus spp.). The complexes were found to be more potent as compared to the ligands.

Fluorescence properties of Schiff base - N,N‧-bis(salicylidene) - 1,2-Phenylenediamine in presence of bile acid host

NASA Astrophysics Data System (ADS)

Roy, Nayan; Paul, Pradip C.; Singh, T. Sanjoy

2015-05-01

Fluorescence properties of Schiff base - N,N‧-bis(salicylidene) - 1,2-phenylenediamine (LH2) is used to study the micelles formed by aggregation of different important bile acids like cholic acid, deoxycholic acid, chenodeoxycholic acid and glycocholic acid by steady state and picosecond time-resolved fluorescence spectroscopy. The fluorescence band intensity was found out to increase with concomitant red shift with gradual addition of different bile acids. Binding constant of the probe with different bile acids as well as critical micelle concentration was obtained from the variation of fluorescence intensity on increasing concentration of bile acids in the medium. The increase in fluorescence quantum yields, fluorescence decay times and substantial decrease in nonradiative decay rate constants in bile acids micellar environment points to the restricted motion of the fluorophore inside the micellar subdomains.

Exploring DNA binding and nucleolytic activity of few 4-aminoantipyrine based amino acid Schiff base complexes: A comparative approach

NASA Astrophysics Data System (ADS)

Raman, N.; Sakthivel, A.; Pravin, N.

A series of novel Co(II), Cu(II), Ni(II) and Zn(II) complexes were synthesized from Schiff base(s), obtained by the condensation of 4-aminoantipyrine with furfural and amino acid (glycine(L1)/alanine(L2)/valine(L3)) and respective metal(II) chloride. Their structural features and other properties were explored from the analytical and spectral methods. The binding behaviors of the complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The intrinsic binding constants for the above synthesized complexes are found to be in the order of 102 to 105 indicating that most of the synthesized complexes are good intercalators. The binding constant values (Kb) clearly indicate that valine Schiff-base complexes have more intercalating ability than alanine and glycine Schiff-base complexes. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens. The IC50 values of [Ni(L1)2] and [Zn(L1)2] complexes imply that these complexes have preferable ability to scavenge hydroxyl radical.

A heterobimetallic Ga/Yb-Schiff base complex for catalytic asymmetric alpha-addition of isocyanides to aldehydes.

PubMed

Mihara, Hisashi; Xu, Yingjie; Shepherd, Nicholas E; Matsunaga, Shigeki; Shibasaki, Masakatsu

2009-06-24

Development of a new heterobimetallic Ga(O-iPr)(3)/Yb(OTf)(3)/Schiff base 2d complex for catalytic asymmetric alpha-additions of isocyanides to aldehydes is described. Schiff base 2d derived from o-vanillin was suitable to utilize cationic rare earth metal triflates with good Lewis acidity in bimetallic Schiff base catalysis. The Ga(O-iPr)(3)/Yb(OTf)(3)/Schiff base 2d complex promoted asymmetric alpha-additions of alpha-isocyanoacetamides to aryl, heteroaryl, alkenyl, and alkyl aldehydes in good to excellent enantioselectivity (88-98% ee).

Design, characterization, teratogenicity testing, antibacterial, antifungal and DNA interaction of few high spin Fe(II) Schiff base amino acid complexes

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.; Lashin, Fakhr El-Din

2013-07-01

In this study, new Fe(II) Schiff base amino acid chelates derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized via elemental, thermogravimetric analysis, molar conductance, IR, electronic, mass spectra and magnetic moment measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. Correlation of all spectroscopic data suggested that Schiff bases ligands exhibited tridentate with ONO sites coordinating to the metal ions via protonated phenolic-OH, azomethine-N and carboxylate-O with the general formulae [Fe(HL)2]·nH2O. But in case of L-histidine, the ligand acts as tetradentate via deprotonated phenolic-OH, azomethine-N, carboxylate-O and N-imidazole ring ([FeL(H2O)2]·2H2O), where HL = mono anion and L = dianion of the ligand. The structure of the prepared complexes is suggested to be octahedral. The prepared complexes were tested for their teratogenicity on chick embryos and found to be safe until a concentration of 100 μg/egg with full embryos formation. Moreover, the interaction between CT-DNA and the investigated complexes were followed by spectrophotometric and viscosity measurements. It was found that, the prepared complexes bind to DNA via classical intercalative mode and showed a different DNA activity with the sequence: nhi > nari > nali > nasi > nphali. Furthermore, the free ligands and their complexes are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus flavus and Trichotheium rosium in order to assess their antimicrobial potential. The results show that the metal complexes are more reactive with respect to their corresponding Schiff base amino acid ligands.

Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

PubMed

Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

2014-01-01

Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

Stereoconversion of amino acids and peptides in uryl-pendant binol schiff bases.

PubMed

Park, Hyunjung; Nandhakumar, Raju; Hong, Jooyeon; Ham, Sihyun; Chin, Jik; Kim, Kwan Mook

2008-01-01

(S)-2-Hydroxy-2'-(3-phenyluryl-benzyl)-1,1'-binaphthyl-3-carboxaldehyde (1) forms Schiff bases with a wide range of nonderivatized amino acids, including unnatural ones. Multiple hydrogen bonds, including resonance-assisted ones, fix the whole orientation of the imine and provoke structural rigidity around the imine C==N bond. Due to the structural difference and the increase in acidity of the alpha proton of the amino acid, the imine formed with an L-amino acid (1-l-aa) is converted into the imine of the D-amino acid (1-D-aa), with a D/L ratio of more than 10 for most amino acids at equilibrium. N-terminal amino acids in dipeptides are also predominantly epimerized to the D form upon imine formation with 1. Density functional theory calculations show that 1-D-Ala is more stable than 1-L-Ala by 1.64 kcal mol(-1), a value that is in qualitative agreement with the experimental result. Deuterium exchange of the alpha proton of alanine in the imine form was studied by (1)H NMR spectroscopy and the results support a stepwise mechanism in the L-into-D conversion rather than a concerted one; that is, deprotonation and protonation take place in a sequential manner. The deprotonation rate of L-Ala is approximately 16 times faster than that of D-Ala. The protonation step, however, appears to favor L-amino acid production, which prevents a much higher predominance of the D form in the imine. Receptor 1 and the predominantly D-form amino acid can be recovered from the imine by simple extraction under acidic conditions. Hence, 1 is a useful auxiliary to produce D-amino acids of industrial interest by the conversion of naturally occurring L-amino acids or relatively easily obtainable racemic amino acids.

Synthesis, physicochemical studies, embryos toxicity and DNA interaction of some new Iron(II) Schiff base amino acid complexes

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.

2013-05-01

New Fe(II) Schiff base amino acid complexes derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized by elemental analysis, IR, electronic spectra, and conductance measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. The investigated Schiff bases exhibited tridentate coordination mode with the general formulae [Fe(HL)2]·nH2O for all amino acids except L-histidine. But in case of L-histidine, the ligand acts as tetradentate ([FeL(H2O)2]·2H2O), where HL = mono anion and L = dianion of the ligand. The structure of the prepared complexes is suggested to be octahedral. The prepared complexes were tested for their toxicity on chick embryos and found to be safe until a concentration of 100 μg/egg with full embryos formation. The interaction between CT-DNA and the investigated complexes were followed by spectrophotometry and viscosity measurements. It was found that, the prepared complexes bind to DNA via classical intercalative mode and showed a different DNA cleavage activity with the sequence: nhi > nari > nali > nasi > nphali. The thermodynamic Profile of the binding of nphali complex and CT-DNA was constructed by analyzing the experimental data of absorption titration and UV melting studies with the McGhee equation, van't Hoff's equation, and the Gibbs-Helmholtz equation.

Synthesis and spectroscopic properties of novel asymmetric Schiff bases.

PubMed

Güngör, Ozlem; Gürkan, Perihan

2010-09-15

Three novel diimine Schiff bases including two asymmetric imines (2-OH)R-CHN-C(6)H(4)-CHN-R'(2-OH) type [where R=R'=phenyl for H(2)L(1); R=naphthyl, R'=phenyl for H(2)L(2) and R=R'=naphthyl for H(2)L(3)] have been synthesized with a new two step method. For this purpose, the starting Schiff bases 4-nitrobenzylidene-2-hydroxyaniline (SB(1)-NO(2)) and 4-nitrobenzylidene-2-hydroxy-3-naphthylamine (SB(2)-NO(2)) have been synthesized, previously. Nitro groups of them have been reduced into their amino derivatives (SB(1)-NH(2) and SB(2)-NH(2)) with sodium dithionite as selective reductant and the other imino groups have been formed by adding salicylaldehyde or 2-hydroxy-1-naphthaldehyde to the same solutions. The structures of the diimine Schiff bases were confirmed by elemental analyses, ESI-MS, FT-IR, (1)H NMR and (13)C NMR spectroscopy. The phenol-imine and keto-amine tautomerism of the Schiff bases were investigated by FT-IR, (1)H NMR, (13)C NMR techniques and UV-vis spectra in different solvents (DMSO, methanol, chloroform, toluene and cyclohexane). The effects of acidic and basic media on the tautomeric equilibria were discussed. Copyright 2010 Elsevier B.V. All rights reserved.

Structural and molecular docking studies of biologically active mercaptopyrimidine Schiff bases

NASA Astrophysics Data System (ADS)

Kirubavathy, S. Jone; Velmurugan, R.; Karvembu, R.; Bhuvanesh, N. S. P.; Enoch, Israel V. M. V.; Selvakumar, P. Mosae; Premnath, D.; Chitra, S.

2017-01-01

Novel Schiff bases derived from the treatment of mercapto-diamino pyrimidine with two different aldehydes are characterized using elemental analysis, single crystal X-ray diffraction and 1H NMR spectroscopy. The pharmacological action of the synthesized compounds viz., antimicrobial, anticancer and antitubercular activities is studied. The Schiff bases show a very good activity against various test pathogens. DNA and β-CD binding interactions of the compounds are studied using UV-Visible absorption and fluorescence spectral measurements. The binding constants of the compounds towards β-CD are in the order of 103 to 104. Molecular docking is done using MOE program on the 3D structure of the enzymes, viz., human thymidylate synthase complexed with dump and raltitrex, candida albicans N-myristoyltransferasepeptidic inhibitor, catalytic domain of protein kinase pKnb from mycobacterium tuberculosis in complex with mitoxantrone, pare, topoisomerase atpase inhibitor, E. coli and lactobacillus casdihydrofolatereductase. The MIC/IC50 values of the Schiff bases are compared with the glide scores from the molecular docking studies. The number of hydrogen bonding interactions between the Schiff bases and amino acid residues are also reported.

Periodic acid‑Schiff staining method for function detection of liver cells is affected by 2% horse serum in induction medium.

PubMed

Hui, Hui; Ma, Wenjun; Cui, Jiejie; Gong, Mengjia; Wang, Yi; Zhang, Yuanyuan; He, Tongchuan; Bi, Yang; He, Yun

2017-12-01

Developing a thorough understanding of experimental methods of hepatic differentiation in hepatic progenitor cells (HPCs) should expand the knowledge of hepatocyte induction in vitro and may help to develop cell transplantation therapies for the clinical usage of HPCs in liver diseases. A previous induction method effectively induced differentiation and metabolic abilities in HPCs. Periodic acid‑Schiff (PAS) staining is used to identify glycogen synthesis and hepatocyte function; however, this method failed to detect induced hepatocytes. The present study aimed to investigate the possible factors affecting the previous confusing results of PAS staining. Removal of single induction factors, including dexamethasone, hepatic growth factor and fibroblast growth factor 4 from the induction media did not restore PAS staining, whereas replacement of 2% horse serum (HS) with 10% fetal bovine serum (FBS) significantly increased the number of PAS positive cells. Following 12 days of basal induction, replacing the induction medium with media containing 10% FBS for 12‑72 h significantly improved PAS staining, but did not influence indocyanine green uptake. Furthermore, incubation in induction medium with 10% FBS following 12 days of normal induction did not affect the expression of hepatic markers and mature function of HPCs. Therefore, the present study suggested that 2% HS in the induction medium did not affect the hepatic function of induced cells, but did affect glycogen storage, whereas replacement of medium with 10% FBS in advance of PAS staining may restore the failure of PAS staining in low serum concentrations of induced hepatocytes.

Multi-wavelength spectrophotometric determination of acidity constant of some newly synthesized Schiff bases and their QSPR study

NASA Astrophysics Data System (ADS)

Hemmateenejad, Bahram; Emami, Leila; Sharghi, Hashem

2010-01-01

The acidity constants of some newly synthesized Schiff base derivatives were determined by hard-model based multivariate data analysis of the spectrophotometric data in the course of pH-metric titration in 50% (v/v) methanol-water binary solvent. The employed data analysis method was also able to extract the pure spectra and pH-dependent concentration profiles of the acid-base species. The molecules that possess different substituents (both electron donating and withdrawing) on the ortho-, meta- and para-positions of one of the phenyl ring showed variable acidity constants ranging from 8.77 to 11.07 whereas the parent molecule had an acidity constant of 10.25. To investigate the quantitative effects of changing of substitution pattern on the acidity constant, a quantitative structure-property relation analysis was conducted using substituent constants and molecular descriptor. Some models with high statistical quality (measured by cross-validation Q2) were obtained. It was found that the acidity constant of the studied molecules in the methanol-water mixed solvent not only is affected by electronic features of the solutes but also by the lipophilic interaction between methanol part of solvent and the deprotonated solutes.

Antimicrobial Activity and Urease Inhibition of Schiff Bases Derived from Isoniazid and Fluorinated Benzaldehydes and of Their Copper(II) Complexes.

PubMed

Habala, Ladislav; Varényi, Samuel; Bilková, Andrea; Herich, Peter; Valentová, Jindra; Kožíšek, Jozef; Devínsky, Ferdinand

2016-12-17

In order to evaluate the influence of substitution on biological properties of Schiff bases and their metal complexes, a series of differently substituted fluorine-containing Schiff bases starting from the drug isoniazid (isonicotinylhydrazide) were prepared and their structures were established by single-crystal X-ray diffraction. Also, four copper(II) complexes of these Schiff bases were synthesized. The prepared compounds were evaluated for their antimicrobial activity and urease inhibition. Two of the Schiff bases exerted activity against C. albicans . All copper(II) complexes showed excellent inhibitory properties against jack bean urease, considerably better than that of the standard inhibitor acetohydroxamic acid.

Keto-enol tautomerism in asymmetric Schiff bases derived from p-phenylenediamine

NASA Astrophysics Data System (ADS)

Užarević, Krunoslav; Rubčić, Mirta; Stilinović, Vladimir; Kaitner, Branko; Cindrić, Marina

2010-12-01

Reaction of dehydroacetic acid and p-phenylenediamine afforded a monosubstituted Schiff base, I, with the other amino group free. In further reactions with various salicylaldehyde derivatives, I served as a precursor for synthesis of asymmetric bis-Schiff bases. The synthesized compounds are thus comprised of two subunits, dehydroacetic ( dha) and salicylidene ( sal), which are bridged by the phenylene linker. All products were investigated by means of elemental analysis, FT-IR and NMR spectroscopy, thermal methods, powder X-ray diffraction and, when possible, by single crystal X-ray crystallography. Structural and spectroscopic studies revealed that in the bis-products, the dha subunit adopts the keto-amino tautomeric form, while the sal subunit adopts the enol-imino form. Tautomeric forms were not affected if a methoxo group was introduced on the salicylidene ring. Both tautomeric subunits are stabilized by strong resonance-assisted hydrogen bonds, RAHB. The two subunits of the prepared bis-Schiff bases predominantly retain in solution the same tautomeric forms as found in the solid state.

Subcutaneous aspergillosis with coexisting atypical mycobacterial infection.

PubMed

Duraipandian, Jeyakumari; Rengasamy, Gopal; Madasamy, Balamurugan; Kulanthaivelu, Ambedkarraj; Subramanian, Girija

2010-01-01

A 60-year-old woman, a known diabetic and asthmatic, was admitted for acute exacerbation of chronic obstructive pulmonary disease. Physical examination revealed two soft nodules in the left infra axillary region. Fine needle aspiration cytology (FNAC) showed fungal granulomatous reaction suggestive of fungal infection. Periodic acid Schiff stain (PAS stain) revealed PAS positive, acutely branching, septate fungal hyphae. Wet mount of the aspirate revealed plenty of pus cells and branching septate hyphae. Ziehl-Neelsen (ZN) stain showed moderate numbers of acid fast bacilli. Culture yielded Aspergillus flavus and Mycobacterium fortuitum.

PAS-cal: a Generic Recombinant Peptide Calibration Standard for Mass Spectrometry

NASA Astrophysics Data System (ADS)

Breibeck, Joscha; Serafin, Adam; Reichert, Andreas; Maier, Stefan; Küster, Bernhard; Skerra, Arne

2014-08-01

We describe the design, preparation, and mass-spectrometric characterization of a new recombinant peptide calibration standard with uniform biophysical and ionization characteristics for mass spectrometry. "PAS-cal" is an artificial polypeptide concatamer of peptide cassettes with varying lengths, each composed of the three small, chemically stable amino acids Pro, Ala, and Ser, which are interspersed by Arg residues to allow site-specific cleavage with trypsin. PAS-cal is expressed at high yields in Escherichia coli as a Small Ubiquitin-like MOdifier (SUMO) fusion protein, which is easily purified and allows isolation of the PAS-cal moiety after SUMO protease cleavage. Upon subsequent in situ treatment with trypsin, the PAS-cal polypeptide yields a set of four defined homogeneous peptides in the range from 2 to 8 kDa with equal mass spacing. ESI-MS analysis revealed a conveniently interpretable raw spectrum, which after deconvolution resulted in a very simple pattern of four peaks with similar ionization signals. MALDI-MS analysis of a PAS-cal peptide mixture comprising both the intact polypeptide and its tryptic fragments revealed not only the four standard peptides but also the singly and doubly charged states of the intact concatamer as well as di- and trimeric adduct ion species between the peptides, thus augmenting the observable m/z range. The advantageous properties of PAS-cal are most likely a result of the strongly hydrophilic and conformationally disordered PEG-like properties of the PAS sequences. Therefore, PAS-cal offers an inexpensive and versatile recombinant peptide calibration standard for mass spectrometry in protein/peptide bioanalytics and proteomics research, the composition of which may be further adapted to fit individual needs.

Oxidation of benzoin catalyzed by oxovanadium(IV) schiff base complexes

PubMed Central

2013-01-01

Background The oxidative transformation of benzoin to benzil has been accomplished by the use of a wide variety of reagents or catalysts and different reaction procedures. The conventional oxidizing agents yielded mainly benzaldehyde or/and benzoic acid and only a trace amount of benzil. The limits of practical utilization of these reagents involves the use of stoichiometric amounts of corrosive acids or toxic metallic reagents, which in turn produce undesirable waste materials and required high reaction temperatures. In recent years, vanadium complexes have attracted much attention for their potential utility as catalysts for various types of reactions. Results Active and selective catalytic systems of new unsymmetrical oxovanadium(IV) Schiff base complexes for the oxidation of benzoin is reported. The Schiff base ligands are derived between 2-aminoethanol and 2-hydroxy-1-naphthaldehyde (H2L1) or 3-ethoxy salicylaldehyde (H2L3); and 2-aminophenol and 3-ethoxysalicylaldehyde (H2L2) or 2-hydroxy-1-naphthaldehyde (H2L4). The unsymmetrical Schiff bases behave as tridentate dibasic ONO donor ligands. Reaction of these Schiff base ligands with oxovanadyl sulphate afforded the mononuclear oxovanadium(IV) complexes (VIVOLx.H2O), which are characterized by various physico-chemical techniques. The catalytic oxidation activities of these complexes for benzoin were evaluated using H2O2 as an oxidant. The best reaction conditions are obtained by considering the effect of solvent, reaction time and temperature. Under the optimized reaction conditions, VOL4 catalyst showed high conversion (>99%) with excellent selectivity to benzil (~100%) in a shorter reaction time compared to the other catalysts considered. Conclusion Four tridentate ONO type Schiff base ligands were synthesized. Complexation of these ligands with vanadyl(IV) sulphate leads to the formation of new oxovanadium(IV) complexes of type VIVOL.H2O. Elemental analyses and spectral data of the free ligands and their

Oxidation of benzoin catalyzed by oxovanadium(IV) schiff base complexes.

PubMed

Alsalim, Tahseen A; Hadi, Jabbar S; Ali, Omar N; Abbo, Hanna S; Titinchi, Salam Jj

2013-01-07

The oxidative transformation of benzoin to benzil has been accomplished by the use of a wide variety of reagents or catalysts and different reaction procedures. The conventional oxidizing agents yielded mainly benzaldehyde or/and benzoic acid and only a trace amount of benzil. The limits of practical utilization of these reagents involves the use of stoichiometric amounts of corrosive acids or toxic metallic reagents, which in turn produce undesirable waste materials and required high reaction temperatures.In recent years, vanadium complexes have attracted much attention for their potential utility as catalysts for various types of reactions. Active and selective catalytic systems of new unsymmetrical oxovanadium(IV) Schiff base complexes for the oxidation of benzoin is reported. The Schiff base ligands are derived between 2-aminoethanol and 2-hydroxy-1-naphthaldehyde (H2L1) or 3-ethoxy salicylaldehyde (H2L3); and 2-aminophenol and 3-ethoxysalicylaldehyde (H2L2) or 2-hydroxy-1-naphthaldehyde (H2L4). The unsymmetrical Schiff bases behave as tridentate dibasic ONO donor ligands. Reaction of these Schiff base ligands with oxovanadyl sulphate afforded the mononuclear oxovanadium(IV) complexes (VIVOLx.H2O), which are characterized by various physico-chemical techniques.The catalytic oxidation activities of these complexes for benzoin were evaluated using H2O2 as an oxidant. The best reaction conditions are obtained by considering the effect of solvent, reaction time and temperature. Under the optimized reaction conditions, VOL4 catalyst showed high conversion (>99%) with excellent selectivity to benzil (~100%) in a shorter reaction time compared to the other catalysts considered. Four tridentate ONO type Schiff base ligands were synthesized. Complexation of these ligands with vanadyl(IV) sulphate leads to the formation of new oxovanadium(IV) complexes of type VIVOL.H2O.Elemental analyses and spectral data of the free ligands and their oxovanadium(IV) complexes were

Mono-Schiff-base or di-Schiff-base? Synthesis, spectroscopic, X-ray structural and DFT study of a series of Schiff-bases derived from benzil dihydrazone

NASA Astrophysics Data System (ADS)

Tan, Xue-Jie; Hao, Xiu-Qi; Zhao, Qing-Zhe; Cheng, Shuang-Shuang; Xie, Wen-Long; Xing, Dian-Xiang; Liu, Yun; Song, Lai-Zhou

2015-11-01

A series of mono- and di-Schiff-bases based on Benzil Dihydrazone (BDH) were designed and synthesized to be set as the model compounds to explain which one should be the advanced product and which parameters will determine the end-product. As the first step of a series of investigations, this article presents the syntheses and characterization of five new Schiff-bases plus one preliminary reported Schiff-base, all derived from BDH. The compounds were characterized by single crystal (or conventional powder) X-ray diffractometry, elemental analysis, m.p., 1H NMR, 13C NMR, IR and UV-Vis. Structural features of the five new Schiff-bases are similar. For instance, all molecules are nonsymmetrical/symmetrical double helix with the torsion angle of two "half-parts" about 72-97°. The Ph-Cdbnd N-Ndbnd C-Ph moiety all exists in planar and anti form, indicating significant conjugation. The crystal structures appear to be stabilized by π-stacking between the aromatic rings, as well as by intermolecular hydrogen bonds and C-H … π stacking interactions. DFT calculations have been performed to explain the trend of the experimentally measured reaction yields. In the case of the studied systems by us, the type of Schiff-bases exhibits a clear dependence on the molar ratio of reactants if the products have similar stabilities. Otherwise the importance of reaction conditions will be weakened and the most stable product will be favored.

A history of US Army PAs.

PubMed

Chalupa, Robyn L; Marble, W Sanders

2017-11-01

The US military has a long tradition of using physician assistants (PAs). The Army began using PAs in 1971 in an effort to supplement the physicians and surgeons in the medical corps. As their numbers grew, PAs gradually replaced general medical officers assigned to battalions. Later, specialty positions developed in aviation medicine, orthopedics, and emergency medicine. The need for a PA serving as an adviser in the major commands slowly developed at all levels of leadership. In 2015, the Army removed limitations on female PAs assigned to combat units. PAs lead in tactical and clinical settings, filling command roles, senior clinical positions, and administrative leadership roles.

Effects of Schiff Base Formation and Aldol Condensation on the Determination of Aldehydes in Rice Wine Using GC-MS.

PubMed

Han, Ji Hye; Lee, Sang Mi; Kim, Young-Suk

2017-04-11

The Schiff base reaction and aldol condensation that occur during sample preparation can lead to the reduction of aldehyde content in the analysis of traditional Korean rice wine, makgeolli. The contents of aldehydes were decreased, whereas those of hydroxy carbonyl compounds were increased by increasing the pH. In the presence of added amino acids, the levels of aldehydes in makgeolli were reduced as the amount of the amino acid alanine increased. Also, the contents of hydroxyl carbonyl compounds were reduced by alanine addition as compared to the control. Therefore, the determination of aldehydes can be affected by pH and the amount of amino acids, which can vary during fermentation and storage of alcoholic beverages because pH and amino acids affect Schiff base formation and aldol condensation.

Histopathological examination of nail clippings using PAS staining (HPE-PAS): gold standard in diagnosis of Onychomycosis.

PubMed

Jeelani, Shazia; Ahmed, Qazi Masood; Lanker, Audil Mohmad; Hassan, Iffat; Jeelani, Nasir; Fazili, Tawheeda

2015-01-01

Onychomycosis is fungal infection of one or more of the nail units. However, because fungi cause only about half of all nail dystrophies, the use of appropriate diagnostic techniques is important to ensure correct diagnosis and treatment. Aim of the present study was to compare direct microscopy, culture and HPE-PAS for diagnosis of onychomycosis by evaluating their sensitivity and various other relevant statistical parameters. A prospective, hospital-based, cross-sectional study was conducted on 216 patients with a high degree of clinical suspicion of onychomycosis. Nail specimens were evaluated using three diagnostic methods, i.e. direct microscopy using 20% Potassium hydroxide (KOH) & 40% Di-methyl-suphoxide (DMSO), culture and histopathological examination using PAS stain (HPE-PAS). Of 216 patients direct microscopy was positive in 138 (63.9%), culture in 147 (68%) and HPE-PAS in 164 patients (76%). One hundred and seventy-nine patients fitted into the criteria set for confirmed diagnosis of onychomycosis. Using this as a denominator; direct microscopy, culture and HPE-PAS had sensitivities of 77.1%, 70% and 91.6% respectively. Also, HPE-PAS showed the highest sensitivity of 94.7% in 19 cases with prediagnostic antimycotic treatment compared to direct microscopy (42.1%) or culture (57.9%). HPE-PAS shows high sensitivity for diagnosis of onychomycosis and can be considered as a gold standard in the diagnosis of onychomycosis. © 2014 Blackwell Verlag GmbH.

Spectral characterization of novel ternary zinc(II) complexes containing 1,10-phenanthroline and Schiff bases derived from amino acids and salicylaldehyde-5-sulfonates

NASA Astrophysics Data System (ADS)

Boghaei, Davar M.; Gharagozlou, Mehrnaz

2007-07-01

A series of new ternary zinc(II) complexes [Zn(L 1-10)(phen)], where phen is 1,10-phenanthroline and H 2L 1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, L-phenylalanine, L-valine, L-alanine, and L-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δ ν ( νas(COO) - νs(COO)) of 191-225 cm -1, indicating a monodentate coordination of the carboxylate group. Spectral data showed that in these ternary complexes the zinc atom is coordinated with the Schiff base ligand acts as a tridentate ONO moiety, coordinating to the metal through its phenolic oxygen, imine nitrogen, and carboxyl oxygen, and also with the neutral planar chelating ligand, 1,10-phenanthroline, coordinating through nitrogens.

Schiff bases in medicinal chemistry: a patent review (2010-2015).

PubMed

Hameed, Abdul; Al-Rashida, Mariya; Uroos, Maliha; Abid Ali, Syed; Khan, Khalid Mohammed

2017-01-01

Schiff bases are synthetically accessible and structurally diverse compounds, typically obtained by facile condensation between an aldehyde, or a ketone with primary amines. Schiff bases contain an azomethine (-C = N-) linkage that stitches together two or more biologically active aromatic/heterocyclic scaffolds to form various molecular hybrids with interesting biological properties. Schiff bases are versatile metal complexing agents and have been known to coordinate all metals to form stable metal complexes with vast therapeutic applications. Areas covered: This review aims to provide a comprehensive overview of the various patented therapeutic applications of Schiff bases and their metal complexes from 2010 to 2015. Expert opinion: Schiff bases are a popular class of compounds with interesting biological properties. Schiff bases are also versatile metal complexing ligands and have been used to coordinate almost all d-block metals as well as lanthanides. Therapeutically, Schiff bases and their metal complexes have been reported to exhibit a wide range of biological activities such as antibacterial including antimycobacterial, antifungal, antiviral, antimalarial, antiinflammatory, antioxidant, pesticidal, cytotoxic, enzyme inhibitory, and anticancer including DNA damage.

Reductive evolution and the loss of PDC/PAS domains from the genus Staphylococcus

PubMed Central

2013-01-01

Background The Per-Arnt-Sim (PAS) domain represents a ubiquitous structural fold that is involved in bacterial sensing and adaptation systems, including several virulence related functions. Although PAS domains and the subclass of PhoQ-DcuS-CitA (PDC) domains have a common structure, there is limited amino acid sequence similarity. To gain greater insight into the evolution of PDC/PAS domains present in the bacterial kingdom and staphylococci in specific, the PDC/PAS domains from the genomic sequences of 48 bacteria, representing 5 phyla, were identified using the sensitive search method based on HMM-to-HMM comparisons (HHblits). Results A total of 1,007 PAS domains and 686 PDC domains distributed over 1,174 proteins were identified. For 28 Gram-positive bacteria, the distribution, organization, and molecular evolution of PDC/PAS domains were analyzed in greater detail, with a special emphasis on the genus Staphylococcus. Compared to other bacteria the staphylococci have relatively fewer proteins (6–9) containing PDC/PAS domains. As a general rule, the staphylococcal genomes examined in this study contain a core group of seven PDC/PAS domain-containing proteins consisting of WalK, SrrB, PhoR, ArlS, HssS, NreB, and GdpP. The exceptions to this rule are: 1) S. saprophyticus lacks the core NreB protein; 2) S. carnosus has two additional PAS domain containing proteins; 3) S. epidermidis, S. aureus, and S. pseudintermedius have an additional protein with two PDC domains that is predicted to code for a sensor histidine kinase; 4) S. lugdunensis has an additional PDC containing protein predicted to be a sensor histidine kinase. Conclusions This comprehensive analysis demonstrates that variation in PDC/PAS domains among bacteria has limited correlations to the genome size or pathogenicity; however, our analysis established that bacteria having a motile phase in their life cycle have significantly more PDC/PAS-containing proteins. In addition, our analysis revealed a

Reductive evolution and the loss of PDC/PAS domains from the genus Staphylococcus.

PubMed

Shah, Neethu; Gaupp, Rosmarie; Moriyama, Hideaki; Eskridge, Kent M; Moriyama, Etsuko N; Somerville, Greg A

2013-07-31

The Per-Arnt-Sim (PAS) domain represents a ubiquitous structural fold that is involved in bacterial sensing and adaptation systems, including several virulence related functions. Although PAS domains and the subclass of PhoQ-DcuS-CitA (PDC) domains have a common structure, there is limited amino acid sequence similarity. To gain greater insight into the evolution of PDC/PAS domains present in the bacterial kingdom and staphylococci in specific, the PDC/PAS domains from the genomic sequences of 48 bacteria, representing 5 phyla, were identified using the sensitive search method based on HMM-to-HMM comparisons (HHblits). A total of 1,007 PAS domains and 686 PDC domains distributed over 1,174 proteins were identified. For 28 Gram-positive bacteria, the distribution, organization, and molecular evolution of PDC/PAS domains were analyzed in greater detail, with a special emphasis on the genus Staphylococcus. Compared to other bacteria the staphylococci have relatively fewer proteins (6-9) containing PDC/PAS domains. As a general rule, the staphylococcal genomes examined in this study contain a core group of seven PDC/PAS domain-containing proteins consisting of WalK, SrrB, PhoR, ArlS, HssS, NreB, and GdpP. The exceptions to this rule are: 1) S. saprophyticus lacks the core NreB protein; 2) S. carnosus has two additional PAS domain containing proteins; 3) S. epidermidis, S. aureus, and S. pseudintermedius have an additional protein with two PDC domains that is predicted to code for a sensor histidine kinase; 4) S. lugdunensis has an additional PDC containing protein predicted to be a sensor histidine kinase. This comprehensive analysis demonstrates that variation in PDC/PAS domains among bacteria has limited correlations to the genome size or pathogenicity; however, our analysis established that bacteria having a motile phase in their life cycle have significantly more PDC/PAS-containing proteins. In addition, our analysis revealed a tremendous amount of variation in the

Synthesis, spectroscopic, thermal and electrical conductivity studies of three charge transfer complexes formed between 1,3-di[( E)-1-(2-hydroxyphenyl)methylideneamino]-2-propanol Schiff base and different acceptors

NASA Astrophysics Data System (ADS)

Refat, Moamen S.; Ibrahim, Mohamed M.; Moussa, Mohamed A. A.

2012-01-01

Charge-transfer complexes (CTC) resulting from interactions of 1,3-di[( E)-1-(2-hydroxyphenyl) methylideneamino]-2-propanol Schiff base with some acceptors such as iodine (I2), bromine (Br2), and picric acid (PiA) have been isolated in the solid state in a chloroform solvent at room temperature. Based on elemental analysis, UV-Vis, infrared, and 1H NMR spectra, and thermogravimetric analysis (TG/DTG) of the solid CTC, [(Schiff)(I2)] (1), [(Schiff)(Br2)] complexes with a ratio of 1:1 and [(Schiff)(PiA)3] complexes with 1:3 have been prepared. In the picric acid complex, infrared and 1H NMR spectroscopic data indicate that the charge-transfer interaction is associated with a hydrogen bonding, whereas the iodine and bromine complexes were interpreted in terms of the formation of dative ion pairs [Schiff+, I{2/•-}] and [Schiff+, Br{2/•-}], respectively. Kinetic parameters were obtained for each stage of thermal degradation of the CT complexes using Coats-Redfern and Horowitz-Metzger methods. DC electrical properties as a function of temperature of these charge transfer complexes have been studied.

Experimental and theoretical studies of Schiff bases as corrosion inhibitors.

PubMed

Jamil, Dalia M; Al-Okbi, Ahmed K; Al-Baghdadi, Shaimaa B; Al-Amiery, Ahmed A; Kadhim, Abdulhadi; Gaaz, Tayser Sumer; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

2018-02-05

Relatively inexpensive, stable Schiff bases, namely 3-((4-hydroxybenzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ3) and 3-((4-(dimethylamino)benzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ4), were employed as highly efficient inhibitors of mild steel corrosion by corrosive acid. The inhibition efficiencies were estimated based on weight loss method. Moreover, scanning electron microscopy was used to investigate the inhibition mechanism. The synthesized Schiff bases were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and micro-elemental analysis. The inhibition efficiency depends on three factors: the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight. Inhibition efficiencies of 96 and 92% were achieved with BZ4 and BZ3, respectively, at the maximum tested concentration. Density functional theory calculations of BZ3 and BZ4 were performed to compare the effects of hydroxyl and N,N-dimethylamino substituents on the inhibition efficiency, providing insight for designing new molecular structures that exhibit enhanced inhibition efficiencies.

Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases; Part 1: alkyl halide alkylations.

PubMed

Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim A

2013-10-01

Alkylations of chiral or achiral Ni(II) complexes of glycine Schiff bases constitute a landmark in the development of practical methodology for asymmetric synthesis of α-amino acids. Straightforward, easy preparation as well as high reactivity of these Ni(II) complexes render them ready available and inexpensive glycine equivalents for preparing a wide variety of α-amino acids, in particular on a relatively large scale. In the case of Ni(II) complexes containing benzylproline moiety as a chiral auxiliary, their alkylation proceeds with high thermodynamically controlled diastereoselectivity. Similar type of Ni(II) complexes derived from alanine can also be used for alkylation providing convenient access to quaternary, α,α-disubstituted α-amino acids. Achiral type of Ni(II) complexes can be prepared from picolinic acid or via recently developed modular approach using simple secondary or primary amines. These Ni(II) complexes can be easily mono/bis-alkylated under homogeneous or phase-transfer catalysis conditions. Origin of diastereo-/enantioselectivity in the alkylations reactions, aspects of practicality, generality and limitations of this methodology is critically discussed.

Spanish validation of the Premorbid Adjustment Scale (PAS-S).

PubMed

Barajas, Ana; Ochoa, Susana; Baños, Iris; Dolz, Montse; Villalta-Gil, Victoria; Vilaplana, Miriam; Autonell, Jaume; Sánchez, Bernardo; Cervilla, Jorge A; Foix, Alexandrina; Obiols, Jordi E; Haro, Josep Maria; Usall, Judith

2013-02-01

The Premorbid Adjustment Scale (PAS) has been the most widely used scale to quantify premorbid status in schizophrenia, coming to be regarded as the gold standard of retrospective assessment instruments. To examine the psychometric properties of the Spanish version of the PAS (PAS-S). Retrospective study of 140 individuals experiencing a first episode of psychosis (n=77) and individuals who have schizophrenia (n=63), both adult and adolescent patients. Data were collected through a socio-demographic questionnaire and a battery of instruments which includes the following scales: PAS-S, PANSS, LSP, GAF and DAS-sv. The Cronbach's alpha was performed to assess the internal consistency of PAS-S. Pearson's correlations were performed to assess the convergent and discriminant validity. The Cronbach's alpha of the PAS-S scale was 0.85. The correlation between social PAS-S and total PAS-S was 0.85 (p<0.001); while for academic PAS-S and total PAS-S it was 0.53 (p<0.001). Significant correlations were observed between all the scores of each age period evaluated across the PAS-S scale, with a significance value less than 0.001. There was a relationship between negative symptoms and social PAS-S (0.20, p<0.05) and total PAS-S (0.22, p<0.05), but not with academic PAS-S. However, there was a correlation between academic PAS-S and general subscale of the PANSS (0.19, p<0.05). Social PAS-S was related to disability measures (DAS-sv); and academic PAS-S showed discriminant validity with most of the variables of social functioning. PAS-S did not show association with the total LSP scale (discriminant validity). The Spanish version of the Premorbid Adjustment Scale showed appropriate psychometric properties in patients experiencing a first episode of psychosis and who have a chronic evolution of the illness. Moreover, each domain of the PAS-S (social and academic premorbid functioning) showed a differential relationship to other characteristics such as psychotic symptoms, disability

Benzaldehyde Schiff bases regulation to the metabolism, hemolysis, and virulence genes expression in vitro and their structure-microbicidal activity relationship.

PubMed

Xia, Lei; Xia, Yu-Fen; Huang, Li-Rong; Xiao, Xiao; Lou, Hua-Yong; Liu, Tang-Jingjun; Pan, Wei-Dong; Luo, Heng

2015-06-05

There is an urgent need to develop new antibacterial agents because of multidrug resistance by bacteria and fungi. Schiff bases (aldehyde or ketone-like compounds) exhibit intense antibacterial characteristics, and are therefore, promising candidates as antibacterial agents. To investigate the mechanism of action of newly designed benzaldehyde Schiff bases, a series of high-yielding benzaldehyde Schiff bases were synthesized, and their structures were determined by NMR and MS spectra data. The structure-microbicidal activity relationship of derivatives was investigated, and the antibacterial mechanisms were investigated by gene assays for the expression of functional genes in vitro using Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The active compounds were selective for certain active groups. The polar substitution of the R2 group of the amino acids in the Schiff bases, affected the antibacterial activity against E. coli and S. aureus; specific active group at the R3 or R4 groups of the acylhydrazone Schiff bases could improve their inhibitory activity against these three tested organisms. The antibacterial mechanism of the active benzaldehyde Schiff bases appeared to regulate the expression of metabolism-associated genes in E. coli, hemolysis-associated genes in B. subtilis, and key virulence genes in S. aureus. Some benzaldehyde Schiff bases were bactericidal to all the three strains and appeared to regulate gene expression associated with metabolism, hemolysis, and virulence, in vitro. The newly designed benzaldehyde Schiff bases possessed unique antibacterial activity and might be potentially useful for prophylactic or therapeutic intervention of bacterial infections. Copyright © 2015. Published by Elsevier Masson SAS.

Ford Partnership for Advanced Studies (Ford PAS)

ERIC Educational Resources Information Center

Carrier, Cheryl

2006-01-01

This article features the Ford Partnership for Advanced Studies (Ford PAS) program that helps students gain knowledge about real-life business issues. Ford PAS is an educational program that combines college-prep academics with the critical 21st century skills students will need to succeed in college and in the workplace. The Ford PAS program uses…

Synthesis, spectral, thermal and optical properties of Schiff-base complexes derived from 2(E)-2-((z)-4-hydroxypent-3-en-2-ylideneamino)-5-guanidinopentanoic acid and acetylacetone

NASA Astrophysics Data System (ADS)

Hosny, Nasser Mohammed; Hussien, Mostafa A.; Radwan, Fatima M.; Nawar, Nagwa

2017-09-01

New metal complexes derived from the in situ reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H2L) resulted from the condensation of 2-amino-5-guanidinopentanoic acid (arginine) and acetylacetone have been synthesized. The resulting complexes have been characterized by, elemental analyses, ES-MS, IR, Raman spectra, UV-Vis., 1HNMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that, The Schiff-base ligand acts as bi-negative tridentate coordinating via azomethine nitrogen, enolic carbonyl oxygen and carboxylate oxygen after displacement of hydrogen. The thermodynamic parameters E∗, ΔH, ΔG and ΔS of the isolated complexes have been calculated. The optical band gap (Eg) values of Cu, Co, Ni and Zn were found to be 3.3, 3.4, 3.7 and 4.3 eV, respectively, arising from direct transitions. Optical band gap measurements indicate the semi-conductivity nature of these complexes.

A Schiff base connectivity switch in sensory rhodopsin signaling

PubMed Central

Sineshchekov, Oleg A.; Sasaki, Jun; Phillips, Brian J.; Spudich, John L.

2008-01-01

Sensory rhodopsin I (SRI) in Halobacterium salinarum acts as a receptor for single-quantum attractant and two-quantum repellent phototaxis, transmitting light stimuli via its bound transducer HtrI. Signal-inverting mutations in the SRI–HtrI complex reverse the single-quantum response from attractant to repellent. Fast intramolecular charge movements reported here reveal that the unphotolyzed SRI–HtrI complex exists in two conformational states, which differ by their connection of the retinylidene Schiff base in the SRI photoactive site to inner or outer half-channels. In single-quantum photochemical reactions, the conformer with the Schiff base connected to the cytoplasmic (CP) half-channel generates an attractant signal, whereas the conformer with the Schiff base connected to the extracellular (EC) half-channel generates a repellent signal. In the wild-type complex the conformer equilibrium is poised strongly in favor of that with CP-accessible Schiff base. Signal-inverting mutations shift the equilibrium in favor of the EC-accessible Schiff base form, and suppressor mutations shift the equilibrium back toward the CP-accessible Schiff base form, restoring the wild-type phenotype. Our data show that the sign of the behavioral response directly correlates with the state of the connectivity switch, not with the direction of proton movements or changes in acceptor pKa. These findings identify a shared fundamental process in the mechanisms of transport and signaling by the rhodopsin family. Furthermore, the effects of mutations in the HtrI subunit of the complex on SRI Schiff base connectivity indicate that the two proteins are tightly coupled to form a single unit that undergoes a concerted conformational transition. PMID:18852467

A Schiff base connectivity switch in sensory rhodopsin signaling.

PubMed

Sineshchekov, Oleg A; Sasaki, Jun; Phillips, Brian J; Spudich, John L

2008-10-21

Sensory rhodopsin I (SRI) in Halobacterium salinarum acts as a receptor for single-quantum attractant and two-quantum repellent phototaxis, transmitting light stimuli via its bound transducer HtrI. Signal-inverting mutations in the SRI-HtrI complex reverse the single-quantum response from attractant to repellent. Fast intramolecular charge movements reported here reveal that the unphotolyzed SRI-HtrI complex exists in two conformational states, which differ by their connection of the retinylidene Schiff base in the SRI photoactive site to inner or outer half-channels. In single-quantum photochemical reactions, the conformer with the Schiff base connected to the cytoplasmic (CP) half-channel generates an attractant signal, whereas the conformer with the Schiff base connected to the extracellular (EC) half-channel generates a repellent signal. In the wild-type complex the conformer equilibrium is poised strongly in favor of that with CP-accessible Schiff base. Signal-inverting mutations shift the equilibrium in favor of the EC-accessible Schiff base form, and suppressor mutations shift the equilibrium back toward the CP-accessible Schiff base form, restoring the wild-type phenotype. Our data show that the sign of the behavioral response directly correlates with the state of the connectivity switch, not with the direction of proton movements or changes in acceptor pK(a). These findings identify a shared fundamental process in the mechanisms of transport and signaling by the rhodopsin family. Furthermore, the effects of mutations in the HtrI subunit of the complex on SRI Schiff base connectivity indicate that the two proteins are tightly coupled to form a single unit that undergoes a concerted conformational transition.

Antimicrobial salicylaldehyde Schiff bases: synthesis, characterization and evaluation.

PubMed

Adeel-Sharif, Hafiz Muhammad; Ahmed, Dildar; Mir, Hira

2015-03-01

As the pathogens soon develop resistance to the existing antibiotics, the demand for new and more effective anti-microbial agents is a continuous phenomenon. In this paper we are reporting synthesis and spectral data of eight Schiff bases of salicylaldehyde with different amines, and evaluation of their anti-microbial activities against different bacterial strains. The bases were synthesized by reflux method, and their structures were determined based FT-IR, (1)H-NMR, (13)C-NMR and Mass spectrometric data. The Schiff bases synthesized included 2-{[(Z)-(2-hydroxyphenyl) methylidene] amino}benzoicacid (SB1), 4-{[(Z)-(2-hydroxyphenyl) methylidene] amino} benzoic acid (SB2),2-[(naphthalene-2-ylimino)methyl] phenol(SB3),2-2'-[benzene-1,4-diylbis(nitrilomethylylidene)]diphenol (SB4), 2-2'-[benzene-1,2-diylbis (nitrile-(E)-methylylidene)]diphenol (SB5), 2-[(2-phenylhydrazineylidene)methyl]phenol (SB6), 2-2'-[ethene-1,2-diylbis(iminomethanediyl)]diphenol (SB7) and 2-[(Z)-(phenylimino)methyl]phenol (SB8). The anti-microbial activities of synthesized Schiff bases were determined in terms of zones of inhibition and minimum inhibitory concentrations (MICs). All the bases showed moderate to good activities against all the tested microorganisms. The MICs of most compounds were 100-200βg/mL against different microorganisms. However, it was 50βg/mL for SB1 against P. aeruginosa (1), SB3 against P. aurantiaca, P. aeruginosa (1), E. coli (2), S. typhi (2) and C. freundii, SB4against E. coli (2), S. typhi (1) and S. maltophilia, SB5 against K. pneumoniae and S. typhi (2), SB6 against P. aeruginosa (3) and C. freundii, SB7 against E. cloacae and A. lipoferum, and SB8 against E. coli (2). Considerably active bases may prove to be potential candidates for future antibiotic drugs.

Development and cytotoxicity of Schiff base derivative as a fluorescence probe for the detection of L-Arginine

NASA Astrophysics Data System (ADS)

Shang, Xuefang; Li, Jie; Guo, Kerong; Ti, Tongyu; Wang, Tianyun; Zhang, Jinlian

2017-04-01

Inspired from biological counter parts, chemical modification of Schiff base derivatives with function groups may provide a highly efficient method to detect amino acids. Therefore, a fluorescent probe involving Schiff base and hydroxyl group has been designed and prepared, which showed high response and specificity for Arginine (Arg) among normal eighteen standard kinds of amino acids (Alanine, Valine, Leucine, Isoleucine, Methionine, Asparticacid, Glutamicacid, Arginine, Glycine, Serine, Threonine, Asparagine, Phenylalanine, Histidine, Tryptophan, Proline, Lysine, Glutamine, Tyrosine and Cysteine). Furthermore, theoretical investigation further illustrated the possible binding mode in the host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. In addition, the synthesized fluorescent probe exhibited high binding ability for Arg and low cytotoxicity to MCF-7 cells over a concentration range of 0-200 μg mL-1 which can be also used as a biosensor for the Arg detection in vivo.

A lecithin phosphatidylserine and phosphatidic acid complex (PAS) reduces symptoms of the premenstrual syndrome (PMS): Results of a randomized, placebo-controlled, double-blind clinical trial.

PubMed

Schmidt, Katja; Weber, Nicole; Steiner, Meir; Meyer, Nadin; Dubberke, Anne; Rutenberg, David; Hellhammer, Juliane

2018-04-01

Many women experience emotional and physical symptoms around the time of ovulation and more so before menstruation interfering with their daily normal life also known as premenstrual syndrome (PMS). Recent observational data suggest that supplementation with Lipogen's phosphatidylserine (PS) and phosphatidic acid (PA) complex (PAS) alleviates these PMS symptoms. The aim of this study was to confirm these observations on the effects of PAS on PMS symptom severity within a controlled clinical trial setting. Forty women aged 18-45 years with a diagnosis of PMS were assigned to either take PAS (containing 400 mg PS & 400 mg PA per day) or a matching placebo. The study comprised 5 on-site visits including 1 baseline menstrual cycle followed by 3 treatment cycles. Treatment intake was controlled for by using an electronic device, the Medication Event Monitoring System (MEMS ® ). Primary outcome of the study was the PMS symptoms severity as assessed by using the Daily Record of Severity of Problems (DRSP). Further, SIPS questionnaire (a German version of the Premenstrual Symptoms Screening Tool (PSST)), salivary hormone levels (cortisol awakening response (CAR) and evening cortisol levels) as well as serum levels (cortisol, estradiol, progesterone and corticosteroid binding globulin (CBG)) were assessed. PMS symptoms as assessed by the DRSP Total score showed a significantly better improvement (p = 0.001) over a 3 cycles PAS intake as compared to placebo. In addition, PAS treated women reported a greater improvement in physical (p = 0.002) and depressive symptoms (p = 0.068). They also reported a lower reduction of productivity (p = 0.052) and a stronger decrease in interference with relationships with others (p = 0.099) compared to the placebo group. No other DRSP scale or item showed significant results. Likewise, the reduction in the number of subjects fulfilling PMS or premenstrual dysphoric disorder (PMDD) criteria as classified by the SIPS did not

Phenoxyacetohydrazide Schiff bases: β-glucuronidase inhibitors.

PubMed

Jamil, Waqas; Perveen, Shagufta; Shah, Syed Adnan Ali; Taha, Muhammad; Ismail, Nor Hadiani; Perveen, Shahnaz; Ambreen, Nida; Khan, Khalid M; Choudhary, Muhammad I

2014-06-25

Phenoxyacetohydrazide Schiff base analogs 1-28 have been synthesized and their in vitro β-glucouoronidase inhibition potential studied. Compounds 1 (IC50=9.20±0.32 µM), 5 (IC50=9.47±0.16 µM), 7 (IC50=14.7±0.19 µM), 8 (IC50=15.4±1.56 µM), 11 (IC50=19.6±0.62 µM), 12 (IC50=30.7±1.49 µM), 15 (IC50=12.0±0.16 µM), 21 (IC50=13.7±0.40 µM) and 22 (IC50=22.0±0.14 µM) showed promising β-glucuronidase inhibition activity, better than the standard (D-saccharic acid-1,4-lactone, IC50=48.4±1.25 µM).

Synthesis, spectroscopic characterization, and antibacterial evaluation of new Schiff bases bearing benzimidazole moiety

NASA Astrophysics Data System (ADS)

Redayan, Muayed Ahmed; Salih Hussein, Maha; Tark lafta, Ashraf

2018-05-01

The present work comprise synthesis of new derivatives for Schiff bases bearing benzimidazole ring. Compounds 1(a-d) were prepared by reaction of o-pheneylenediamine with a various of amino acids (glycine, alanine, phenyl alanine and tyrosine) in the presence 6N HCl to yielded derivatives of benzimidazole compounds containing free –NH2 group. Then these compounds used to prepare different Schiff bases through reaction with various of aromatic aldehydes. The chemical structure of synthesized compounds were confirmed by FTIR,1H,13C-NMR, and 13C-NMR dept135 spectroscopy. Some selected compounds were evaluated in vitro for their antibacterial activity against two types of Gram-positive bacteria namely (Staphylococcous aureus, Bacillus subtilis) and Gram-negative bacteria namely (Pseudomonas aeruginosa, Escherichia coli). Most of the results of the antibacterial activity of these compounds were good when compared with the standard antibiotic ampicillin and ciprofloxacin.

Discriminative staining methods for the nervous system: luxol fast blue--periodic acid-Schiff--hematoxylin triple stain and subsidiary staining methods.

PubMed

Goto, N

1987-09-01

This paper describes a new series of staining methods which can discriminatively demonstrate every structure of the nervous system, including axons and capillaries, in animal and human materials. Methods described in this paper consist of one primary stain, luxol fast blue-periodic acid Schiff-hematoxylin (LPH) and six different subsidiary staining methods. The LPH triple stain can precisely differentiate the following structures: neurons (Nissl bodies, cytoplasm, nuclear membrane and nucleolus), various kinds of nuclei (glia, ependyma, endothelium, leucocyte, connective tissue, etc.), myelin sheaths, neuronal processes (axons and dendrites), reacted glial cell bodies (protoplasmic astrocytes, foamy cells, etc.), blood vessels (arteries, veins and capillaries), meninges, intervening connective tissue, erythrocytes, lipofuscin granules, amyloid bodies, and others. Subsidiary staining methods are also described briefly. Applications are discussed in the context of staining technology and neuromorphological research.

Spectral characterization, cyclic voltammetry, morphology, biological activities and DNA cleaving studies of amino acid Schiff base metal(II) complexes

NASA Astrophysics Data System (ADS)

Neelakantan, M. A.; Rusalraj, F.; Dharmaraja, J.; Johnsonraja, S.; Jeyakumar, T.; Sankaranarayana Pillai, M.

2008-12-01

Metal complexes are synthesized with Schiff bases derived from o-phthalaldehyde (opa) and amino acids viz., glycine (gly) L-alanine (ala), L-phenylalanine (pal). Metal ions coordinate in a tetradentate or hexadentate manner with these N 2O 2 donor ligands, which are characterized by elemental analysis, molar conductance, magnetic moments, IR, electronic, 1H NMR and EPR spectral studies. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). Based on EPR studies, spin-Hamiltonian and bonding parameters have been calculated. The g-values calculated for copper complexes at 300 K and in frozen DMSO (77 K) indicate the presence of the unpaired electron in the d orbital. The evaluated metal-ligand bonding parameters showed strong in-plane σ- and π-bonding. X-ray diffraction (XRD) and scanning electron micrography (SEM) analysis provide the crystalline nature and the morphology of the metal complexes. The cyclic voltammograms of the Cu(II)/Mn(II)/VO(II) complexes investigated in DMSO solution exhibit metal centered electroactivity in the potential range -1.5 to +1.5 V. The electrochemical data obtained for Cu(II) complexes explains the change of structural arrangement of the ligand around Cu(II) ions. The biological activity of the complexes has been tested on eight bacteria and three fungi. Cu(II) and Ni(II) complexes show an increased activity in comparison to the controls. The metal complexes of opapal Schiff base were evaluated for their DNA cleaving activities with calf-thymus DNA (CT DNA) under aerobic conditions. Cu(II) and VO(II) complexes show more pronounced activity in presence of the oxidant.

Female PAs-Where are we today?

PubMed

Curtis, L Gail; Dobbs, Lauren; Hildebrandt, Carol A

2017-09-01

As the physician assistant (PA) profession celebrates its 50th birthday, we can be proud of the gains our profession has accomplished. However, despite the positive reports of job satisfaction, a marked increase in female PA leaders, and overall gains in PA compensation, a significant wage gap remains between male and female PAs. The PA profession is flourishing but it is time female PAs are paid equitably.

Stereoselective synthesis of unsaturated α-amino acids.

PubMed

Fanelli, Roberto; Jeanne-Julien, Louis; René, Adeline; Martinez, Jean; Cavelier, Florine

2015-06-01

Stereoselective synthesis of unsaturated α-amino acids was performed by asymmetric alkylation. Two methods were investigated and their enantiomeric excess measured and compared. The first route consisted of an enantioselective approach induced by the Corey-Lygo catalyst under chiral phase transfer conditions while the second one involved the hydroxypinanone chiral auxiliary, both implicating Schiff bases as substrate. In all cases, the use of a prochiral Schiff base gave higher enantiomeric excess and yield in the final desired amino acid.

New Tetra-Schiff Bases as Efficient Photostabilizers for Poly(vinyl chloride).

PubMed

Ahmed, Dina S; El-Hiti, Gamal A; Hameed, Ayad S; Yousif, Emad; Ahmed, Ahmed

2017-09-09

Three new tetra-Schiff bases were synthesized and characterized to be used as photostabilizers for poly(vinyl chloride) (PVC) films. The photostability of PVC films (40 μm thickness) in the presence of Schiff bases (0.5 wt %) upon irradiation (300 h) with a UV light (λ max = 365 nm and light intensity = 6.43 × 10 -9 ein∙dm -3 ∙s -1 ) was examined using various spectroscopic measurements and surface morphology analysis. The changes in various functional groups' indices, weight and viscosity average molecular weight of PVC films were monitored against irradiation time. The additives used showed photostability for PVC films, with Schiff base 1 being the most effective additive upon irradiation, followed by 2 and 3 . The atomic force microscopy (AFM) images for the PVC surface containing Schiff base 1 after irradiation were found to be smooth, with a roughness factor ( R q) of 36.8, compared to 132.2 for the PVC (blank). Several possible mechanisms that explain PVC photostabilization upon irradiation in the presence of tetra-Schiff bases were proposed.

A gallium(III) Schiff base-curcumin complex that binds to amyloid-β plaques.

PubMed

Lange, Jaclyn L; Hayne, David J; Roselt, Peter; McLean, Catriona A; White, Jonathan M; Donnelly, Paul S

2016-09-01

Gallium-68 is a positron-emitting isotope that can be used in positron-emission tomography imaging agents. Alzheimer's disease is associated with the formation of plaques in the brain primarily comprised of aggregates of a 42 amino acid protein called amyloid-β. With the goal of synthesising charge neutral, low molecular weight, lipophilic gallium complexes with the potential to cross the blood-brain barrier and bind to Aβ plaques we have used an ancillary tetradentate N 2 O 2 Schiff base ligand and the β-diketone curcumin as a bidentate ligand to give a six-coordinate Ga 3+ complex. The tetradentate Schiff base ligand adopts the cis-β configuration with deprotonated curcumin acting as a bidentate ligand. The complex binds to amyloid-β plaques in human brain tissue and it is possible that extension of this chemistry to positron-emitting gallium-68 could provide useful imaging agents for Alzheimer's disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Synthesis and photoluminescence properties of novel Schiff base type polymer-rare earth complexes containing furfural-based bidentate Schiff base ligands

NASA Astrophysics Data System (ADS)

Gao, Baojiao; Zhang, Dandan; Li, Yanbin

2018-03-01

Luminescent polymer-rare earth complexes are an important class of photoluminescence and electroluminescence materials. Via molecular design, two furfural-based bidentate Schiff base ligands, furfural-aniline (FA) type ligand and furfural-cyclohexylamine (FC) type ligand, were bonded on the side chains of polysulfone (PSF), respectively, forming two functionalized macromolecules, PSF-FA and PSF-FC. And then through respective coordination reactions of the two functionalized macromolecules with Eu(Ⅲ) ion and Tb(Ⅲ) ion, novel luminescent binary and ternary (with 1,10-phenanthroline as the second ligand) polymer-rare earth complexes were synthesized. For these complexes, on basis of the characterization of their chemical structures, they photoluminescence properties were main researched, and the relationship between their luminescent properties and structures was explored. The experimental results show that the complexes coming from PSF-FA and Eu(Ⅲ) ion including binary and ternary complexes emit strong red luminescence, indicating that the bonded bidentate Schiff base ligand FA can sensitize the fluorescence emission of Eu(III) ion. While the complexes coming from PSF-FC and Tb(Ⅲ) ion produce green luminescence, displaying that the bonded bidentate Schiff base ligand FC can sensitize the fluorescence emission of Tb(Ⅲ) ion. The fluorescence emission intensities of the ternary complexes were stronger than that of binary complexes, reflecting the important effect of the second ligand. The fluorescence emission of the solid film of complexes is much stronger than that of the solutions of complexes. Besides, by comparison, it is found that the furfural (as a heteroaromatic compound)-based Schiff base type polymer-rare earth complexes have stronger fluorescence emission and higher energy transfer efficiency than salicylaldehyde (as a common aromatic compound)-based Schiff base type polymer-rare earth complexes.

Pulmonary hyalinosis in dogs.

PubMed

Dagle, G E; Filipy, R E; Adee, R R; Stuart, B O

1976-01-01

Pulmonary hyalinosis occurred in Beagles exposed to radon daughters with uranium ore dust. The lesion was composed of alveolar cells distended with material positive for periodic acid-Schiff (PAS) and oil red O that ultrastructurally consisted of a whorled arrangement of lamellar membranes suggestive of a storage disease. The high incidence in exposed dogs and the ultrastructural appearance suggested the material originated endogenously as a degenerative response to injury.

Investigation of irradiated rats DNA in the presence of Cu(II) chelates of amino acids Schiff bases.

PubMed

Karapetyan, N H; Torosyan, A L; Malakyan, M; Bajinyan, S A; Haroutiunian, S G

2016-01-01

The new synthesized Cu(II) chelates of amino acids Schiff bases were studied as a potential radioprotectors. Male albino rats of Wistar strain were exposed to X-ray whole-body irradiation at 4.8 Gy. This dose caused 30% mortality of the animals (LD30). The survival of animals exposed to radiation after preliminary administration of 10 mg/kg Cu(II)(Nicotinyl-L-Tyrosinate)2 or Cu(II)(Nicotinyl-L-Tryptophanate)2 prior to irradiation was registered about 80 and 100% correspondingly. Using spectrophotometric melting and agarose gel electrophoresis methods, the differences between the DNA isolated from irradiated rats and rats pretreated with Cu(II) chelates were studied. The fragments of DNA with different breaks were revealed in DNA samples isolated from irradiated animals. While, the repair of the DNA structure was observed for animals pretreated with the Cu(II) chelates. The results suggested that pretreatment of the irradiated rats with Cu(II)(Nicotinyl-L-Tyrosinate)2 and Cu(II)(Nicotinyl-L-Tryptophanate)2 compounds improves the liver DNA characteristics.

Synthesis and Spectral Characterization of Antifungal Sensitive Schiff Base Transition Metal Complexes

PubMed Central

Sakthivel, A.; Rajasekaran, K.

2007-01-01

New N2O2 donor type Schiff base has been designed and synthesized by condensing acetoacetanilido-4-aminoantipyrine with 2-aminobenzoic acid in ethanol. Solid metal complexes of the Schiff base with Cu(II), Ni(II), Co(II), Mn(II), Zn(II), VO(IV), Hg(II) and Cd(II) metal ions were synthesized and characterized by elemental analyses, magnetic susceptibility, molar conduction, fast atom bombardment (FAB) mass, IR, UV-Vis, and 1H NMR spectral studies. The data show that the complexes have the composition of ML type. The UV-Vis. and magnetic susceptibility data of the complexes suggest a square-planar geometry around the central metal ion except VO(IV) complex which has square-pyramidal geometry. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer, Candida albicans, Rhizoctonia bataicola and Trichoderma harizanum. All the metal complexes showed stronger antifungal activities than the free ligand. The minimum inhibitory concentrations (MIC) of the metal complexes were found in the range of 10~31 µg/ml. PMID:24015086

Development and Evaluation of Cefadroxil Drug Loaded Biopolymeric Films Based on Chitosan-Furfural Schiff Base

PubMed Central

Dixit, Ritu B.; Uplana, Rahul A.; Patel, Vishnu A.; Dixit, Bharat C.; Patel, Tarosh S.

2010-01-01

Cefadroxil drug loaded biopolymeric films of chitosan-furfural schiff base were prepared by reacting chitosan with furfural in presence of acetic acid and perchloric acid respectively for the external use. Prepared films were evaluated for their strength, swelling index, thickness, drug content, uniformity, tensile strength, percent elongation, FTIR spectral analysis and SEM. The results of in vitro diffusion studies revealed that the films exhibited enhanced drug diffusion as compared to the films prepared using untreated chitosan. The films also demonstrated good to moderate antibacterial activities against selective gram positive and gram negative bacteria. PMID:21179325

Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: Synthesis, spectral characterization, antimicrobial and nuclease studies

NASA Astrophysics Data System (ADS)

Subbaraj, P.; Ramu, A.; Raman, N.; Dharmaraja, J.

2014-01-01

A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA = Schiff base and B = 2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, 1H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, 1H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique.

Games network and application to PAs system.

PubMed

Chettaoui, C; Delaplace, F; Manceny, M; Malo, M

2007-02-01

In this article, we present a game theory based framework, named games network, for modeling biological interactions. After introducing the theory, we more precisely describe the methodology to model biological interactions. Then we apply it to the plasminogen activator system (PAs) which is a signal transduction pathway involved in cancer cell migration. The games network theory extends game theory by including the locality of interactions. Each game in a games network represents local interactions between biological agents. The PAs system is implicated in cytoskeleton modifications via regulation of actin and microtubules, which in turn favors cell migration. The games network model has enabled us a better understanding of the regulation involved in the PAs system.

Lorentz-violating contributions to the nuclear Schiff moment and nuclear EDM

NASA Astrophysics Data System (ADS)

Araujo, Jonas B.; Casana, Rodolfo; Ferreira, Manoel M.

2018-03-01

In the context of an atom endowed with nuclear electric dipole moments (EDM), we consider the effects on the Schiff moment of C P T -even Lorentz-violating (LV) terms that modify the Coulomb potential. First, we study the modifications on the Schiff moment when the nucleus interacts with the electronic cloud by means of a Coulomb potential altered only by the P -even LV components. Next, by supposing the existence of an additional intrinsic LV EDM generated by other LV sources, we assess the corrections to the Schiff moment when the interaction nucleus-electrons runs mediated by a Coulomb potential modified by both the P -odd and P -even LV components. We then use known estimates and EDM measurements to discuss upper bounds on the new Schiff moment components and the possibility of a nuclear EDM component ascribed to LV effects.

Multi-PAS domain-mediated protein oligomerization of PpsR from Rhodobacter sphaeroides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heintz, Udo; Meinhart, Anton; Winkler, Andreas, E-mail: andreas.winkler@mpimf-heidelberg.mpg.de

2014-03-01

Crystal structures of two truncated variants of the transcription factor PpsR from R. sphaeroides are presented that enabled the phasing of a triple PAS domain construct. Together, these structures reveal the importance of α-helical PAS extensions for multi-PAS domain-mediated protein oligomerization and function. Per–ARNT–Sim (PAS) domains are essential modules of many multi-domain signalling proteins that mediate protein interaction and/or sense environmental stimuli. Frequently, multiple PAS domains are present within single polypeptide chains, where their interplay is required for protein function. Although many isolated PAS domain structures have been reported over the last decades, only a few structures of multi-PAS proteinsmore » are known. Therefore, the molecular mechanism of multi-PAS domain-mediated protein oligomerization and function is poorly understood. The transcription factor PpsR from Rhodobacter sphaeroides is such a multi-PAS domain protein that, in addition to its three PAS domains, contains a glutamine-rich linker and a C-terminal helix–turn–helix DNA-binding motif. Here, crystal structures of two N-terminally and C-terminally truncated PpsR variants that comprise a single (PpsR{sub Q-PAS1}) and two (PpsR{sub N-Q-PAS1}) PAS domains, respectively, are presented and the multi-step strategy required for the phasing of a triple PAS domain construct (PpsR{sub ΔHTH}) is illustrated. While parts of the biologically relevant dimerization interface can already be observed in the two shorter constructs, the PpsR{sub ΔHTH} structure reveals how three PAS domains enable the formation of multiple oligomeric states (dimer, tetramer and octamer), highlighting that not only the PAS cores but also their α-helical extensions are essential for protein oligomerization. The results demonstrate that the long helical glutamine-rich linker of PpsR results from a direct fusion of the N-cap of the PAS1 domain with the C-terminal extension of the N

Acute Toxicity and Gastroprotection Studies of a New Schiff Base Derived Manganese (II) Complex against HCl/Ethanol-Induced Gastric Ulcerations in Rats.

PubMed

Ibrahim, Mohamed Yousif; Hashim, Najihah Mohd; Dhiyaaldeen, Summaya M; Al-Obaidi, Mazen M Jamil; El-Ferjani, Rashd M; Adam, Hoyam; Alkotaini, Bassam; Batran, Rami Al; Ali, Hapipah Mohd

2016-05-27

Manganese is a crucial element for health. In this study, the gastroprotective efficacy of Mn (II) complex (MDLA) against acidified ethanol (HCl/Ethanol)-induced gastric ulceration in rats was evaluated. The animals were distributed into 5 groups. Groups 1 and 2 received carboxymethylcellulose (CMC), group 3 was pretreated with omeprazole, and groups 4 and 5 were given 10 and 20 mg/kg of MDLA, respectively. After one hour, CMC and HCl/Ethanol were given to groups 2-5 whilst the animals in group 1 were ingested with CMC. After sacrifice, gastric lesions were evaluated by wall mucus, gross appearance, histology, antioxidant enzymes and immunohistochemistry. Group 2 displayed severe gastric damage with a significant reduction in wall mucus. Conversely, gastric lesions were reduced in groups 3-5 by 85.72%, 56.51% and 65.93%, respectively. The rats in groups 3-5 showed up-regulation of heat shock protein 70 (Hsp70) with down-regulation of Bcl-2-associated protein x (Bax). Pretreatment with omeprazole or MDLA led to an increase in the uptake of Periodic Acid Schiff (PAS) stain in the glandular part of the gastric tissue, raised levels of prostaglandin E2 (PGE2) and superoxide dismutase (SOD), and a reduction in malondialdehyde (MDA) concentrations. These results suggested the gastroprotective action of Mn (II) complex.

The productivity of PAs, APRNs, and physicians in Utah.

PubMed

Pedersen, Donald M; Chappell, Boyd; Elison, Gar; Bunnell, Robert

2008-01-01

The physician assistant workforce in Utah is experiencing remarkable growth, with a 9% net annual rate of increase since 1998. An additional 84 PAs provided patient care in Utah in the 4-year period of 1998 through 2001, an average increase of 21 per year. The Utah Medical Education Council believes that the demand for PAs will be high over the next 10 to 15 years, with several factors fueling this growth. Productivity is one of these factors. Even though Utah PAs make up only approximately 6.3% of the state's combined clinician (physician, PA, advanced practice registered nurse [APRN]) workforce; the PAs contribute approximately 7.2% of the patient care full-time equivalents (FTE) in the state. This is in contrast to the 10% FTE contribution made by the state's APRN workforce, which has nearly triple the number of clinicians providing patient care in the state. The majority (73%) of Utah PAs work at least 36 hours per week. Utah PAs also spend a greater percentage of the total hours worked in patient care, when compared to the physician workforce. The rural PA workforce reported working a greater number of total hours and patient care hours when compared to the overall PA workforce.

Synthesis of new kojic acid based unnatural α-amino acid derivatives.

PubMed

Balakrishna, C; Payili, Nagaraju; Yennam, Satyanarayana; Uma Devi, P; Behera, Manoranjan

2015-11-01

An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond. Copyright © 2015 Elsevier Ltd. All rights reserved.

Secondary Interactions Arrest the Hemiaminal Intermediate To Invert the Modus Operandi of Schiff Base Reaction: A Route to Benzoxazinones.

PubMed

Patel, Ketan; Deshmukh, Satej S; Bodkhe, Dnyaneshwar; Mane, Manoj; Vanka, Kumar; Shinde, Dinesh; Rajamohanan, Pattuparambil R; Nandi, Shyamapada; Vaidhyanathan, Ramanathan; Chikkali, Samir H

2017-04-21

Discovered by Hugo Schiff, condensation between amine and aldehyde represents one of the most ubiquitous reactions in chemistry. This classical reaction is widely used to manufacture pharmaceuticals and fine chemicals. However, the rapid and reversible formation of Schiff base prohibits formation of alternative products, of which benzoxazinones are an important class. Therefore, manipulating the reactivity of two partners to invert the course of this reaction is an elusive target. Presented here is a synthetic strategy that regulates the sequence of Schiff base reaction via weak secondary interactions. Guided by the computational models, reaction between 2,3,4,5,6-pentafluoro-benzaldehyde with 2-amino-6-methylbenzoic acid revealed quantitative (99%) formation of 5-methyl-2-(perfluorophenyl)-1,2-dihydro-4H-benzo[d][1,3]oxazin-4-one (15). Electron donating and electron withdrawing ortho-substituents on 2-aminobenzoic acid resulted in the production of benzoxazinones 9-36. The mode of action was tracked using low temperature NMR, UV-vis spectroscopy, and isotopic ( 18 O) labeling experiments. These spectroscopic mechanistic investigations revealed that the hemiaminal intermediate is arrested by the hydrogen-bonding motif to yield benzoxazinone. Thus, the mechanistic investigations and DFT calculations categorically rule out the possibility of in situ imine formation followed by ring-closing, but support instead hydrogen-bond assisted ring-closing to prodrugs. This unprecedented reaction represents an interesting and competitive alternative to metal catalyzed and classical methods of preparing benzoxazinone.

Synthesis and biological evaluation of histamine Schiff bases as carbonic anhydrase I, II, IV, VII, and IX activators.

PubMed

Akocak, Suleyman; Lolak, Nabih; Vullo, Daniela; Durgun, Mustafa; Supuran, Claudiu T

2017-12-01

A series of 20 histamine Schiff base was synthesised by reaction of histamine, a well known carbonic anhydrase (CA, E.C 4.2.2.1.) activator pharmacophore, with substituted aldehydes. The obtained histamine Schiff bases were assayed as activators of five selected human (h) CA isozymes, the cytosolic hCA I, hCA II, and hCA VII, the membrane-anchored hCA IV and transmembrane hCA IX. Some of these compounds showed efficient activity (in the nanomolar range) against the cytosolic isoform hCA VII, which is a key CA enzyme involved in brain metabolism. Moderate activity was observed against hCA I and hCA IV (in the nanomolar to low micromolar range). The structure-activity relationship for activation of these isoforms with the new histamine Schiff bases is discussed in detail based on the nature of the aliphatic, aromatic, or heterocyclic moiety present in the aldehyde fragment of the molecule, which may participate in diverse interactions with amino acid residues at the entrance of the active site, where activators bind, and which is the most variable part among the different CA isoforms.

Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: synthesis, spectral characterization, antimicrobial and nuclease studies.

PubMed

Subbaraj, P; Ramu, A; Raman, N; Dharmaraja, J

2014-01-03

A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA=Schiff base and B=2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, (1)H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, (1)H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique. Copyright © 2013 Elsevier B.V. All rights reserved.

Rodent renal structure differs among species.

PubMed

Ichii, Osamu; Yabuki, Akira; Ojima, Toshimichi; Matsumoto, Mitsuharu; Suzuki, Shusaku

2006-05-01

In the present study, we histologically and morphometrically investigated species differences in renal structure using laboratory rodents (mice, gerbils, hamsters, rats, and guinea pigs). Morphometric parameters were as follows, 1) diameter of the cortical renal corpuscles, 2) diameter of the juxtamedullary renal corpuscles, 3) percentage of the renal corpuscles with a cuboidal parietal layer, 4) number of nuclei in proximal convoluted tubules (PCTs) per unit area of cortex, 5) semi-quantitative score of the periodic acid-Schiff (PAS) -positive granules in PCTs, and 6) semi-quantitative score of the PAS-positive granules in proximal straight tubules (PSTs). Significant species differences were detected for each parameter, and particularly severe differences were observed in the PAS-positive granules of PCTs and PSTs. Granular scores varied among species and sexes. Vacuolar structures that did not stain with PAS or hematoxylin-eosin were observed in the renal proximal tubules. The appearance and localization of these vacuolar structures differed remarkably between species and sexes.

Two different forms of metarhodopsin II: Schiff base deprotonation precedes proton uptake and signaling state.

PubMed

Arnis, S; Hofmann, K P

1993-08-15

Rhodopsin is a retinal protein and a G-protein-coupled receptor; it shares with both of these families the seven helix structure. To generate the G-interacting helix-loop conformation, generally identified with the 380-nm absorbing metarhodopsin II (MII) photoproduct, the retinal Schiff base bond to the apoprotein must be deprotonated. This occurs as a key event also in the related retinal proteins, sensory rhodopsins, and the proton pump bacteriorhodopsin. In MII, proton uptake from the aqueous phase must be involved as well, since its formation increases the pH of the aqueous medium and is accelerated under acidic conditions. In the native membrane, the pH effect matches MII formation kinetically, suggesting that intramolecular and aqueous protonation changes contribute in concert to the protein transformation. We show here, however, that proton uptake, as indicated by bromocresol purple, and Schiff base deprotonation (380-nm absorption change) show different kinetics when the protein is solubilized in suitable detergents. Our data are consistent with a two-step reaction:

[Synthesis and spectral characteristics of novel di-schiff base derivatives incorporting oxadiazole ring].

PubMed

Chen, Tong-bin; Zhang, Xiong-lu; Fan, Xiao-lin; Li, Xun

2008-12-01

4-nitrobenzoic acid and hydraxine sulfate were cyclized with H3PO4/P2O5 to afford 2,5-bis(4-nitrophenyl)-1, 3,4-oxadiazole(1), then(1)was reduced to 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole using Zn/CaCl2 as reduction reagent, and at last, a series of novel di-schiff base derivatives containing oxadiazole ring were obtained by the reaction of 2,5-bis(4-aminophenyl)-1, 3,4-oxadiazole with aromatic aldehydes (yield: 65%-81%). The structures of these compounds were confirmed by 1H NMR, FTIR and MS. Their UV-Vis spectra as well as fluorescence spectra were studied and the electrochemical properties were tested with cyclic voltammetry. The UV-Vis spectroscopy results show that the characteristic absorption peaks of 1, 3, 4-oxadiazole unit and di-schiff base unit disappeared. The maximum absorption wavelength was detected at 345-357 nm because conjugation effect made the two energy bands partially hybrid and form a new energy band structure. Fluorescence spectroscopy results show that they emit strong blue and purple fluorescence, and the emission maximum wavelengths of di-schiff base are from 390 to 407 nm. Electrochemical properties results show that they have higher affinity energy (2.36-3.04 eV) and ionic potential (5.35-6.06 eV), which indicated that they have better electron-transporting properties than PBD except 3 a and 3 h. The results give a reference to further application to organic electroluminescent devices of the target compound.

Personal Assistance Services (PAS) for individuals with disabilities: self-care at the workplace.

PubMed

Solovieva, Tatiana I; Walls, Richard T; Dowler, Denetta L

2010-01-01

The intent of this investigation was to identify current definitions, issues, and strategies related to the use of Personal Assistance Services (PAS) in the workplace. The participants were employees with disabilities who used PAS in the workplace as well as employers who participated in research studies over the past 20 years. More than 30 articles were reviewed to determine PAS definitions, use, policies, and outcomes. A comprehensive search of bibliographic resources (e.g., EBSCOhost) was conducted to identify appropriate articles. The articles revealed current definitions of workplace PAS, demonstrated an increasing need for PAS, and highlighted fiscal and societal barriers to the full implementation of PAS at work. The outcomes clarify the historical components, but also identify questions that remain. These questions concern the effectiveness of PAS, best practices for funding PAS, and the need for national and local policies to support the use of PAS for workers with disabilities.

Changes in Quaternary Structure in the Signaling Mechanisms of PAS Domains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayers, Rebecca A.; Moffat, Keith

2008-12-15

FixL from Bradyrhizobium japonicum is a PAS sensor protein in which two PAS domains covalently linked to a histidine kinase domain are responsible for regulating nitrogen fixation in an oxygen-dependent manner. The more C-terminal PAS domain, denoted bjFixLH, contains a heme cofactor that binds diatomic molecules such as carbon monoxide and oxygen and regulates the activity of the FixL histidine kinase as part of a two-component signaling system. We present the structures of ferric, deoxy, and carbon monoxide-bound bjFixLH in a new space group (P1) and at resolutions (1.5--1.8 {angstrom}) higher than the resolutions of those previously obtained. Interestingly, bjFixLHmore » can form two different dimers (in P1 and R32 crystal forms) in the same crystallization solution, where the monomers in one dimer are rotated {approx}175 deg. relative to the second. This suggests that PAS monomers are plastic and that two quite distinct quaternary structures are closely similar in free energy. We use screw rotation analysis to carry out a quantitative pairwise comparison of PAS quaternary structures, which identifies five different relative orientations adopted by isolated PAS monomers. We conclude that PAS monomer arrangement is context-dependent and could differ depending on whether the PAS domains are isolated or are part of a full-length protein. Structurally homologous residues comprise a conserved dimer interface. Using network analysis, we find that the architecture of the PAS dimer interface is continuous rather than modular; the network of residues comprising the interface is strongly connected. A continuous dimer interface is consistent with the low dimer-monomer dissociation equilibrium constant. Finally, we quantitate quaternary structural changes induced by carbon monoxide binding to a bjFixLH dimer, in which monomers rotate by up to 2 deg. relative to each other. We relate these changes to those in other dimeric PAS domains and discuss the role of quaternary

Co(II) and Cd(II) Complexes Derived from Heterocyclic Schiff-Bases: Synthesis, Structural Characterisation, and Biological Activity

PubMed Central

Ahmed, Riyadh M.; Yousif, Enaam I.; Al-Jeboori, Mohamad J.

2013-01-01

New monomeric cobalt and cadmium complexes with Schiff-bases, namely, N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]furan-2-carbohydrazide (L1) and N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]thiophene-2-carbohydrazide (L2) are reported. Schiff-base ligands L1 and L2 were derived from condensation of 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin) with furan-2-carboxylic acid hydrazide and thiophene-2-carboxylic acid hydrazide, respectively. Complexes of the general formula [M(L)2]Cl2 (where M = Co(II) or Cd(II), L = L1 or L2) have been obtained from the reaction of the corresponding metal chloride with the ligands. The ligands and their metal complexes were characterised by spectroscopic methods (FTIR, UV-Vis, 1H, and 13C NMR spectra), elemental analysis, metal content, magnetic measurement, and conductance. These studies revealed the formation of four-coordinate complexes in which the geometry about metal ion is tetrahedral. Biological activity of the ligands and their metal complexes against gram positive bacterial strain Bacillus (G+) and gram negative bacteria Pseudomonas (G−) revealed that the metal complexes become less resistive to the microbial activities as compared to the free ligands. PMID:24027449

Antibacterial and antifungal metal based triazole Schiff bases.

PubMed

Chohan, Zahid H; Hanif, Muhammad

2013-10-01

A new series of four biologically active triazole derived Schiff base ligands (L(1)-L(4)) and their cobalt(II), nickel(II), copper(II) and zinc(II) complexes (1-16) have been synthesized and characterized. The ligands were prepared by the condensation reaction of 3-amino-5-methylthio-1H-1,2,4-triazole with chloro-, bromo- and nitro-substituted 2-hydroxybenzaldehyde in an equimolar ratio. The antibacterial and antifungal bioactivity data showed the metal(II) complexes to be more potent antibacterial and antifungal than the parent Schiff bases against one or more bacterial and fungal species.

Weakly-bridged dimeric diorganotin(IV) compounds derived from pyruvic acid hydrazone Schiff base ligands: Synthesis, characterization and crystal structures

NASA Astrophysics Data System (ADS)

Hong, Min; Yin, Han-Dong; Cui, Ji-Chun

2011-03-01

We report the synthesis of four diorganotin(IV) compounds of Schiff base pyruvic acid hydrazone derivatives formulated as [R 2SnLY] 2, where L 1 is 2-SC 4H 3CON 2C(CH 3)CO 2 with Y = CH 3CH 2CH 2CH 2OH, R = n-Bu ( 1); L 2 is C 6H 5CON 2C(CH 3)CO 2 with Y = CH 3CH 2OH, R = p-F-Bz ( 2); L 3 is 2-HOC 6H 4CON 2C(CH 3)CO 2 with Y dbnd H 2O, R = p-CN -Bz ( 3); and L 4 is 4-NO 2-C 6H 4CON 2C(CH 3)CO 2 with Y dbnd CH 3CH 2OH, R = Bz ( 4). The structures of all compounds have been established by a combination of single-crystal X-ray diffraction analysis, 1H and 119Sn NMR spectroscopy, IR spectroscopy, and elemental analysis. Studies reveal that four ligands present the same coordination mode with tin center, which all present tridentate ONO donor Schiff bases and coordinate to the tin center in an enolic form. In compounds 1- 4, each tin atom is seven-coordinated and exhibits a distorted pentagonal bipyramid with a planar SnO 4N unit and two apical alkyl carbon atoms, thus forming a weakly-bridged dimeric molecule. Additionally, the distance of Sn⋯O bridge in each compound is obviously affected by the choice of different alkyl groups and coordination solvent molecules, which fluctuates in the range of 2.571(5)-2.839(4) Å. Furthermore, the supramolecular structure analysis show that there are two types of supramolecular infrastructures, 1D chain or 2D network, which are formed by intermolecular O-H···N or C-H⋯X (X = O, N or F) hydrogen bonds.

Functional anatomy of the lacrimal gland in African black ostrich Struthio camelus domesticus in the embryonic and postnatal period.

PubMed

Klećkowska-Nawrot, Joanna; Goździewska-Harłajczuk, Karolina; Nowaczyk, Renata; Krasucki, Krzysztof

2015-03-25

The aim of the present study was morphological and histochemical analysis of the lacrimalgland (LG) in African black ostrich Struthio camelus domesticus in the embryonic and postnatalperiod. Studies were conducted on 50 ostriches aged between the 28th day of incubation until7 months old. Tissue sections were stained with haematoxylin and eosin, Azan trichrome,periodic acid-Schiff, Alcian blue pH 2.5, aldehyde fuchsin and Hale's dialysed iron. The LGin ostrich was classified as a tubulo-acinar type. The primordia of the lobes were determinedin the LG structure on the 28th day of incubation, whilst the weakly visible lobes with aciniand tubules were observed on the 40th day of incubation. Morphometric studies of the LGshowed steady growth, characterised by an increase in both length and width. Histometricmeasurements of lobe size showed little difference between the first, second and third agegroups, whilst in the fourth age group a marked increase in size of lobes was observed.The study showed that, apart from morphological changes, during the growth of the LGthe character of acid mucopolysaccharides changed. Sulphated acid mucopolysaccharideswere indicated, particularly with aldehyde fuchsin (AF) staining in the fourth age group.The Hale's dialysed iron (HDI) staining showed a low concentration of carboxylated acidmucopolysaccharides in the first and second age groups and a higher concentration in thethird and fourth age groups. Periodic acid-Schiff staining (PAS)-positive cells were observedin each age group, but only a small number of cells with a weakly PAS-positive reaction weredemonstrated in the first age group.

Poly(vinyl Chloride) Photostabilization in the Presence of Schiff Bases Containing a Thiadiazole Moiety.

PubMed

Shaalan, Naser; Laftah, Nawres; El-Hiti, Gamal A; Alotaibi, Mohammad Hayal; Muslih, Raad; Ahmed, Dina S; Yousif, Emad

2018-04-15

Five Schiff bases containing a thiadiazole moiety have been used as poly(vinyl chloride) photostabilizers at low concentrations. The efficiency of Schiff bases as photostabilizers was investigated using various techniques, for example, the changes in poly(vinyl chloride) infrared spectra, molecular weight, chain scission quantum yield, and surface morphology were monitored upon irradiation with an ultraviolet light. Evidently, all the additives used inhibited poly(vinyl chloride) photodegradation at a significant level. The most efficient Schiff base exhibited a high level of aromaticity and contained a hydroxyl group. It seems possible that such photostabilization could be due to the direct absorption of ultraviolet radiation by the additives. In addition, Schiff bases could act as radical scavengers and proton transfer facilitators to stabilize the polymeric materials.

Microplate assay for screening the antibacterial activity of Schiff bases derived from substituted benzopyran-4-one.

PubMed

Amin, Rehab M; Abdel-Kader, Nora S; El-Ansary, Aida L

2012-09-01

Schiff bases (SB(1)-SB(3)) were synthesized from the condensation of 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one with 2-aminopyridine (SB(1)), p-phenylenediamine (SB(2)) and o-phenylenediamine (SB(3)), while Schiff bases (SB(4)-SB(6)) were synthesized by condensation of 5,7-dihydroxy-6-formyl-2-methylbenzopyran-4-one with 2-aminopyridine (SB(4)), p-phenylenediamine (SB(5)) and o-phenylenediamine (SB(6)). Schiff bases were characterized using elemental analysis, IR, UV-Vis, (1)H NMR, (13)C NMR and mass spectroscopy. These compounds were screened for antibacterial activities by micro-plate assay technique. Escherichia coli and Staphylococcus capitis were exposed to different concentrations of the Schiff bases. Results showed that the antibacterial effect of these Schiff bases on Gram-negative bacteria were higher than that on Gram-positive bacteria moreover, the Schiff bases containing substituent OCH(3) on position five have higher antibacterial activity than that containing hydroxy group on the same position. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis, spectroscopic properties and theoretical studies of bis-Schiff bases derived from polyamine and pyrazolones.

PubMed

Ren, Tiegang; Liu, Shuyun; Li, Guihui; Zhang, Jinglai; Guo, Jia; Li, Weijie; Yang, Lirong

2012-11-01

A series of novel bis-Schiff base were synthesized from 1-aryl-3-methyl-4-benzoyl-5-pyrazolones and diethylenetriamine (or triethylenetetramine) as the starting materials. All of these bis-Schiff bases were characterized by means of NMR, IR, and MS. The UV-vis absorption spectra and fluorescent spectra of these bis-Schiff bases were also measured. Moreover, the B3LYP/6-31G(d) method was used to optimize the ground state geometry of the bis-Schiff bases; and the UV-vis spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVDZ basis set of TD-B3LYP method. It has been found that all of these bis-Schiff bases show a remarkable absorption peak in a wavelength range of 270-340 nm; and their maximum emission peaks are around 348 nm. Copyright © 2012 Elsevier B.V. All rights reserved.

Progress of Chiral Schiff Bases with C1 Symmetry in Metal-Catalyzed Asymmetric Reactions.

PubMed

Hayashi, Masahiko

2016-12-01

In this Personal Account, various chiral Schiff base-metal-catalyzed enantioselective organic reactions are reported; the Schiff bases used were O,N,O- as well as N,N,P-tridentate ligands and N,N-bidentate ligands having C 1 symmetry. In particular, the enantioselective addition of trimethylsilyl cyanide, dialkylzinc, and organozinc halides to aldehydes, enantioselective 1,4-addition of dialkylzinc to cyclic and acyclic enones, and asymmetric allylic oxidation are reported. Typically, ketimine-type Schiff base-metal complexes exhibited higher reactivity and enantioselectivity compared with the corresponding aldimine-type Schiff base-metal complexes. Notably, remarkable ligand acceleration was observed for all reactions. The obtained products can be used as key intermediates for optically active natural products and pharmaceuticals. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Two different forms of metarhodopsin II: Schiff base deprotonation precedes proton uptake and signaling state.

PubMed Central

Arnis, S; Hofmann, K P

1993-01-01

Rhodopsin is a retinal protein and a G-protein-coupled receptor; it shares with both of these families the seven helix structure. To generate the G-interacting helix-loop conformation, generally identified with the 380-nm absorbing metarhodopsin II (MII) photoproduct, the retinal Schiff base bond to the apoprotein must be deprotonated. This occurs as a key event also in the related retinal proteins, sensory rhodopsins, and the proton pump bacteriorhodopsin. In MII, proton uptake from the aqueous phase must be involved as well, since its formation increases the pH of the aqueous medium and is accelerated under acidic conditions. In the native membrane, the pH effect matches MII formation kinetically, suggesting that intramolecular and aqueous protonation changes contribute in concert to the protein transformation. We show here, however, that proton uptake, as indicated by bromocresol purple, and Schiff base deprotonation (380-nm absorption change) show different kinetics when the protein is solubilized in suitable detergents. Our data are consistent with a two-step reaction: Images Fig. 6 PMID:8356093

Cutaneous protothecosis on the bilateral wrists of a food handler.

PubMed

Tan, M; Pan, J Y; Chia, H Y; Oon, H H

2017-01-01

Cutaneous protothecosis is caused by the achlorophyllic algae Prototheca, typically presenting as a localized plaque in immunocompetent individuals. We report a patient with bilateral erythematous plaques and pustules on her forearms, which had initially been treated with steroids for presumed eczema. Histology showed spherical spore-like bodies with internal morula-like septation, which were positive for periodic-acid-Schiff (PAS) staining, consistent with cutaneous protothecosis. Definitive treatment with oral itraconazole resulted in resolution of the lesions. © 2016 British Association of Dermatologists.

Synthesis, characterization and biological activity of some transition metals with Schiff base derived from 2-thiophene carboxaldehyde and aminobenzoic acid.

PubMed

Mohamed, Gehad G; Omar, M M; Hindy, Ahmed M M

2005-12-01

Metal complexes of Schiff base derived from 2-thiophene carboxaldehyde and 2-aminobenzoic acid (HL) are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance and thermal analysis (TGA). The ligand dissociation as well as the metal-ligand stability constants were calculated pH metrically at 25 degrees C and ionic strength mu=0.1 (1M NaCl). The complexes are found to have the formulae [M(HL)2](X)n.yH2O (where M=Fe(III) (X=Cl, n=3, y=3), Co(II) (X=Cl, n=2, y=1.5), Ni(II) (X=Cl, n=2, y=1) and UO2(II) (X=NO3, n=2, y=0)) and [M(L)2] (where M=Cu(II) (X=Cl) and Zn(II) (X=AcO)). The molar conductance data reveal that Fe(III) and Co(II), Ni(II) and UO2(II) chelates are ionic in nature and are of the type 3:1 and 2:1 electrolytes, respectively, while Cu(II) and Zn(II) complexes are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a terdentate manner with ONS donor sites of the carboxylate O, azomethine N and thiophene S. From the magnetic and solid reflectance spectra, it is found that the geometrical structure of these complexes are octahedral. The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, DeltaH*, DeltaS* and DeltaG* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligands, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus pyogones and Fungi (Candida). The activity data show that the metal complexes to be more potent/antibacterial than the parent Schiff base ligand against one or more bacterial species.

Synthesis, characterization and biological activity of some transition metals with Schiff base derived from 2-thiophene carboxaldehyde and aminobenzoic acid

NASA Astrophysics Data System (ADS)

Mohamed, Gehad G.; Omar, M. M.; Hindy, Ahmed M. M.

2005-12-01

Metal complexes of Schiff base derived from 2-thiophene carboxaldehyde and 2-aminobenzoic acid (HL) are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance and thermal analysis (TGA). The ligand dissociation as well as the metal-ligand stability constants were calculated pH metrically at 25 °C and ionic strength μ = 0.1 (1 M NaCl). The complexes are found to have the formulae [M(HL) 2](X) n· yH 2O (where M = Fe(III) (X = Cl, n = 3, y = 3), Co(II) (X = Cl, n = 2, y = 1.5), Ni(II) (X = Cl, n = 2, y = 1) and UO 2(II) (X = NO 3, n = 2, y = 0)) and [M(L) 2] (where M = Cu(II) (X = Cl) and Zn(II) (X = AcO)). The molar conductance data reveal that Fe(III) and Co(II), Ni(II) and UO 2(II) chelates are ionic in nature and are of the type 3:1 and 2:1 electrolytes, respectively, while Cu(II) and Zn(II) complexes are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a terdentate manner with ONS donor sites of the carboxylate O, azomethine N and thiophene S. From the magnetic and solid reflectance spectra, it is found that the geometrical structure of these complexes are octahedral. The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, Δ H*, Δ S* and Δ G* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligands, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus pyogones and Fungi (Candida). The activity data show that the metal complexes to be more potent/antibacterial than the parent Schiff base ligand against one or more bacterial species.

NMR structural study of the prototropic equilibrium in solution of Schiff bases as model compounds.

PubMed

Ortegón-Reyna, David; Garcías-Morales, Cesar; Padilla-Martínez, Itzia; García-Báez, Efren; Aríza-Castolo, Armando; Peraza-Campos, Ana; Martínez-Martínez, Francisco

2013-12-31

An NMR titration method has been used to simultaneously measure the acid dissociation constant (pKa) and the intramolecular NHO prototropic constant ΔKNHO on a set of Schiff bases. The model compounds were synthesized from benzylamine and substituted ortho-hydroxyaldehydes, appropriately substituted with electron-donating and electron-withdrawing groups to modulate the acidity of the intramolecular NHO hydrogen bond. The structure in solution was established by 1H-, 13C- and 15N-NMR spectroscopy. The physicochemical parameters of the intramolecular NHO hydrogen bond (pKa, ΔKNHO and ΔΔG°) were obtained from 1H-NMR titration data and pH measurements. The Henderson-Hasselbalch data analysis indicated that the systems are weakly acidic, and the predominant NHO equilibrium was established using Polster-Lachmann δ-diagram analysis and Perrin model data linearization.

The Ability of PAS, Acetylsalicylic Acid and Calcium Disodium EDTA to Protect Against the Toxic Effects of Manganese on Mitochondrial Respiration in Gill of Crassostrea virginica.

PubMed

Crawford, Sherine; Davis, Kiyya; Saddler, Claudette; Joseph, Jevaun; Catapane, Edward J; Carroll, Margaret A

2011-01-01

Manganese (Mn) is an essential metal that at excessive levels in brain causes Manganism, a condition similar to Parkinson's disease. Previously we showed that Mn had a neurotoxic effect on the dopaminergic, but not serotonergic, innervation of the lateral ciliated cells in the gill of the Eastern Oyster, Crassostrea virginica. While the mechanism of action of Mn toxicity is not completely understood, studies suggest that Mn toxicity may involve mitochondrial damage and resulting neural dysfunction in the brain's dopaminergic system. In this study we utilized micro-batch chambers and oxygen probes to measure oyster gill mitochondrial respiration in the presence of Mn and potential Mn blockers. The addition of Mn to respiring mitochondria caused a dose dependent decrease in mitochondrial O(2) consumption. Pretreating mitochondria with calcium disodium EDTA (caEDTA), p aminosalicylic acid (PAS) or acetylsalicylic acid (ASA) before Mn additions, provided full protection against the toxic effects of Mn. While mitochondrial pretreatment with any of the 3 drugs effectively blocked Mn toxicity, none of the drugs tested was able to reverse the decrease in mitochondrial O(2) consumption seen in Mn treated mitochondria. The study found that high levels of Mn had a toxic effect on gill mitochondrial O(2) consumption and that this effect could be blocked by the drugs caEDTA, PAS and ASA. C. virginica continues to be a good model with which to investigate the mechanism that underlies manganese neurotoxcity and in the pharmacological study of drugs to treat or prevent Manganism.

The Ability of PAS, Acetylsalicylic Acid and Calcium Disodium EDTA to Protect Against the Toxic Effects of Manganese on Mitochondrial Respiration in Gill of Crassostrea virginica

PubMed Central

Crawford, Sherine; Davis, Kiyya; Saddler, Claudette; Joseph, Jevaun; Catapane, Edward J.; Carroll, Margaret A.

2011-01-01

Manganese (Mn) is an essential metal that at excessive levels in brain causes Manganism, a condition similar to Parkinson's disease. Previously we showed that Mn had a neurotoxic effect on the dopaminergic, but not serotonergic, innervation of the lateral ciliated cells in the gill of the Eastern Oyster, Crassostrea virginica. While the mechanism of action of Mn toxicity is not completely understood, studies suggest that Mn toxicity may involve mitochondrial damage and resulting neural dysfunction in the brain’s dopaminergic system. In this study we utilized micro-batch chambers and oxygen probes to measure oyster gill mitochondrial respiration in the presence of Mn and potential Mn blockers. The addition of Mn to respiring mitochondria caused a dose dependent decrease in mitochondrial O2 consumption. Pretreating mitochondria with calcium disodium EDTA (caEDTA), p aminosalicylic acid (PAS) or acetylsalicylic acid (ASA) before Mn additions, provided full protection against the toxic effects of Mn. While mitochondrial pretreatment with any of the 3 drugs effectively blocked Mn toxicity, none of the drugs tested was able to reverse the decrease in mitochondrial O2 consumption seen in Mn treated mitochondria. The study found that high levels of Mn had a toxic effect on gill mitochondrial O2 consumption and that this effect could be blocked by the drugs caEDTA, PAS and ASA. C. virginica continues to be a good model with which to investigate the mechanism that underlies manganese neurotoxcity and in the pharmacological study of drugs to treat or prevent Manganism. PMID:21977482

Carbonic anhydrase inhibitors. Inhibition of human cytosolic isoforms I and II with (reduced) Schiff's bases incorporating sulfonamide, carboxylate and carboxymethyl moieties.

PubMed

Nasr, Gihane; Cristian, Alina; Barboiu, Mihail; Vullo, Daniella; Winum, Jean-Yves; Supuran, Claudiu T

2014-05-15

A library of Schiff bases was synthesized by condensation of aromatic amines incorporating sulfonamide, carboxylic acid or carboxymethyl functionalities as Zn(2+)-binding groups, with aromatic aldehydes incorporating tert-butyl, hydroxy and/or methoxy groups. The corresponding amines were thereafter obtained by reduction of the imines. These compounds were assayed for the inhibition of two cytosolic human carbonic anhydrase (hCA, EC 4.2.1.1) isoenzymes, hCA I and II. The Ki values of the Schiff bases were in the range of 7.0-21,400nM against hCA II and of 52-8600nM against hCA I, respectively. The corresponding amines showed Ki values in the range of 8.6nM-5.3μM against hCA II, and of 18.7-251nM against hCA I, respectively. Unlike the imines, the reduced Schiff bases are stable to hydrolysis and several low-nanomolar inhibitors were detected, most of them incorporating sulfonamide groups. Some carboxylates also showed interesting CA inhibitory properties. Such hydrosoluble derivatives may show pharmacologic applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthesis, characterization and antibacterial activity of biodegradable films prepared from Schiff bases of zein.

PubMed

Soliman, E A; Khalil, A A; Deraz, S F; El-Fawal, G; Elrahman, S Abd

2014-10-01

Pure zein is known to be very hydrophobic, but is still inappropriate for coating and film applications because of their brittle nature. In an attempt to improve the flexibility and the antimicrobial activity of these coatings and films, Chemical modification of zein through forming Schiff bases with different phenolic aldhydes was tried. Influence of this modifications on mechanical, topographical, wetting properties and antimicrobial activity of zein films were evaluated. The chemical structure of the Schiff bases films were characterized by ATR-FTIR spectroscopy. The results indicate an improvement in mechanical properties with chemically modification of zein to form Schiff bases leading to a reduction in the elastic modulus. An increase in the elongation at break has been observed, but with slight influence on tensile strength. Plasticized zein films have similar initial contact angle (∼40°). An increase in reaction temperature and time increases film's affinity towards water. As shown by contact angle measurements, a noticeable relation was found between film composition and the hydrophilicity. Surface topography also varied by forming Schiff bases, becoming rougher than zein-based films. The antibacterial activities of zein and Schiff bases of zein-based films were investigated against gram-positive bacteria (Listeria innocua, Listeria monocytogenes, Bacillus cereus and Clostridium sporogenes) and gram-negative bacteria (Escherichia coli, Yersinia enterocolitica and Salmonella enterica). It was found that the antibacterial activity of the Schiff bases-based films was more effective than that of zein-based films.

Prolinimines: N-Amino-l-Pro-methyl Ester (Hydrazine) Schiff Bases from a Fish Gastrointestinal Tract-Derived Fungus, Trichoderma sp. CMB-F563.

PubMed

Mohamed, Osama G; Khalil, Zeinab G; Capon, Robert J

2018-01-19

A rice cultivation of a fish gastrointestinal tract-derived fungus, Trichoderma sp. CMB-F563, yielded natural products incorporating a rare hydrazine moiety, embedded within a Schiff base. Structures inclusive of absolute configurations were assigned to prolinimines A-D (1-4) on the basis of detailed spectroscopic and C 3 Marfey's analysis, as well as biosynthetic considerations, biomimetic total synthesis, and chemical transformations. Of note, monomeric 1 proved to be acid labile and, during isolation, underwent quantitative transformation to dimeric 3 and trimeric 4. Prolinimines are only the second reported natural products incorporating an N-amino-Pro residue, the first to include l-Pro, the first to occur as Schiff bases, and the first to be isolated from a microorganism.

Synthesis, characterization and biological activity of Schiff bases based on chitosan and arylpyrazole moiety.

PubMed

Salama, Hend E; Saad, Gamal R; Sabaa, Magdy W

2015-08-01

The Schiff bases of chitosan were synthesized by the reaction of chitosan with 3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde. The structure of the prepared chitosan derivatives was characterized by FT-IR spectroscopy, elemental analysis, and X-ray diffraction studies and thermogravimetric analysis (TG). The results show that the specific properties of Schiff bases of chitosan can be altered by modifying the molecular structures with proper substituent groups.TG results reveal that the thermal stability of the prepared chitosan Schiff bases was lower than chitosan. The activation energy of decomposition was calculated using Coats-Redfern model. The antimicrobial activity of chitosan and Schiff bases of chitosan were investigated against Streptococcus pneumonia, Bacillis subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi). The results indicated that the antimicrobial activity of the Schiff bases was stronger than that of chitosan and was dependent on the substituent group. The activity of un-substituted arylpyrazole chitosan derivative toward the investigated bacteria and fungi species was better than the other derivatives. Copyright © 2015 Elsevier B.V. All rights reserved.

How electronic health records can unmask the hidden value of PAs.

PubMed

Ogunfiditimi, Folusho; Sherry, Scott P; Foote, Monica; Christie, Sarah L; Shock, Lisa P; Cawley, James; Browne, Aaron

2017-06-01

The Fee for Value (FFV) Task Force, a subgroup of the American Academy of PAs' Research and Strategic Initiatives Commission, has examined tools and mechanisms aimed at better clarifying the volume and value of PA work and how that work contributes to improving access to high-quality care. Establishing the value of PAs has been a challenging task for many healthcare providers. Often, PA value has been defined by their clinical productivity, without any clear direction as to what constitutes value versus productivity. The objective of this article is to unmask the value of PAs through the role of electronic health records and highlight PAs' ability to produce services that are value-oriented and quantifiably productive.

Photostability and Performance of Polystyrene Films Containing 1,2,4-Triazole-3-thiol Ring System Schiff Bases.

PubMed

Ali, Gassan Q; El-Hiti, Gamal A; Tomi, Ivan Hameed R; Haddad, Raghad; Al-Qaisi, Alaa J; Yousif, Emad

2016-12-09

Series of 4-(4-substituted benzylideneamino)-5-(3,4,5-trimethoxyphenyl)-4 H -1,2,4-triazole-3-thiols were synthesized and their structures were confirmed. The synthesized Schiff bases were used as photostabilizers for polystyrene against photodegradation. Polystyrene polymeric films containing synthesized Schiff bases (0.5% by weight) were irradiated (λ max = 365 nm and light intensity = 6.43 × 10 -9 ein·dm -3 ·s -1 ) at room temperature. The photostabilization effect of 1,2,4-triazole-3-thiols Schiff bases was determined using various methods. All the additives used enhanced the photostability of polystyrene films against irradiation compared with the result obtained in the absence of Schiff base. The Schiff bases can act as photostabilizers for polystyrene through the direct absorption of UV radiation and/or radical scavengers.

Immunohistochemical study of the digestive tract of Oligosarcus hepsetus

PubMed Central

Vieira-Lopes, Danielle A; Pinheiro, Nadja L; Sales, Armando; Ventura, Adriana; Araújo, Francisco G; Gomes, Iracema D; Nascimento, Aparecida A

2013-01-01

AIM: To describe the histology of the digestive tract and to investigate the occurrence of endocrine cells in Oligosarcus hepsetus (O. hepsetus). METHODS: The digestive tract (DT) of O. hepsetus was divided into esophagus, two stomach regions (glandular and non-glandular) and two intestinal regions (anterior and posterior). These specimens were processed by routine histological techniques and stained with hematoxylin-eosin, Gomori’s trichrome, periodic acid Schiff (PAS) and Alcian blue (AB). An immunohistochemical method using avidin-biotin-peroxidase was employed. RESULTS: The esophagus is lined with a non-keratinized stratified squamous epithelium that is reactive to PAS and AB. The stomach has a mucosa lined with a simple columnar epithelium with mucus-secreting cells that are reactive only to PAS. The intestine has a simple columnar epithelium with a brush border and goblet cells that are reactive to PAS and AB. Somatostatin, serotonin and cholecystokinin immunoreactive cells were identified throughout the DT. CONCLUSION: This study revealed adaptations for the species’ diet and showed that the distribution and relative frequency of immunoreactive cells are similar to those of other fish. PMID:23569337

PAs in orthopedics in the VHA's community-based outpatient clinics.

PubMed

Reed, Daniel O; Hooker, Roderick S

2017-04-01

In the Veterans Health Administration (VHA) system, most orthopedic care takes place in the VA medical centers (VAMCs). Because most patients receiving orthopedic care were referred by adult medicine providers, more widely deploying physician assistants (PAs) in orthopedic medicine might help offset this workload. An orthopedic medicine demonstration project recruited, trained, and positioned PAs in community-based outpatient clinics (CBOCs) to improve access to care. The project involved surgeons at the Houston VAMC instructing five newly employed PAs in a wide range of orthopedic evaluation and management strategies before their assignment to a CBOC. An administrative assessment compared encounter data pre- and postproject (2012 and 2014) to determine if this strategy modified orthopedic workload and improved patient access to care. By 2014, orthopedic patient visit volume had increased 31%-10% at the VAMC and 21% at the five CBOCs. Overall, the five deployed PAs managed 28% of all orthopedic encounters spread over 1 year and only 3.2% of visits required VAMC referral for further evaluation or treatment. During the project, the total volume of patient visits increased throughout the Houston VAMC region but access to care for this specialty service also increased, with more veteran musculoskeletal care being met at the five CBOCs, off-loading visit demand centrally. The adaptability and flexibility of new roles has been identified as one of the defining characteristics of PAs. That the VHA can take advantage of this role malleability suggests that employing PAs is useful in meeting medical service needs of veterans.

The electric and thermoelectric properties of Cu(II)-Schiff base nano-complexes

NASA Astrophysics Data System (ADS)

Ibrahim, E. M. M.; Abdel-Rahman, Laila H.; Abu-Dief, Ahmed M.; Elshafaie, A.; Hamdan, Samar Kamel; Ahmed, A. M.

2018-05-01

The physical properties, such as electric and optical properties, of metal-Schiff base complexes have been widely investigated. However, their thermoelectric (TE) properties remain unreported. This work presents Cu(II)-Schiff base complexes as promising materials for TE power generation. Therefore, three Cu(II)-Schiff base complexes (namely, [Cu(C32H22N4O2)].3/2H2O, [Cu(C23H17N4O7Br)], and [Cu(C27H22N4O8)].H2O) have been synthesized in nanosized scale. The electric and TE properties have been studied and comprehensive discussions have been presented to promote the nano-complexes (NCs) practical applications in the field of TE power generation. The electrical measurements confirm that the NCs are semiconductors and the electrical conduction process is governed by intermolecular and intramolecular transfer of the charge carriers. The TE measurements reveal that the Cu(II)-Schiff base NCs are nondegenerate P-type semiconductors. The measured Seebeck coefficient values were higher compared to the values reported in previous works for other organic materials indicating that the complexes under study are promising candidates for theremoelectric applications if the electrical conductivity could be enhanced.

Novel mutations in the gene encoding acid α-1,4-glucosidase in a patient with late-onset glycogen storage disease type II (Pompe disease) with impaired intelligence.

PubMed

Muraoka, Tomie; Murao, Koji; Imachi, Hitomi; Kikuchi, Fumi; Yoshimoto, Takuo; Iwama, Hisakazu; Hosokawa, Hitoshi; Nishino, Ichizo; Fukuda, Tokiko; Sugie, Hideo; Adachi, Kaori; Nanba, Eiji; Ishida, Toshihiko

2011-01-01

A 17-year-old Japanese man was referred to our hospital because of highly elevated serum levels of creatine kinase (CK) and transaminases. On admission, the proximal muscles of the lower extremities were found to be predominantly affected, and a score of 3/5 was obtained on Medical Research Council (MRC) scale. Muscular atrophy was evident and Gowers' sign was positive. His functional vital capacity (FVC) was markedly reduced. The results of the third edition of the Wechsler Adult Intelligence Scale (WAIS-III) indicated impairment of the patient's intelligence. Muscle biopsy showed scattered intracytoplasmic vacuoles with basophilic amorphous materials inside which were strongly stained by both periodic acid Schiff (PAS) and acid phosphatase. Biochemical analysis of the muscle tissue confirmed the diagnosis of GSDII because the glucosidase activity was 1.0 nmol/4 MU/mg/30 min (control range, 7.3 ± 2.2). Genetic analysis revealed a novel compound heterozygous missense mutation in GAA--c.1814 G >A (p.Gly605Asp) and c.1846 G >A (p.Asp616Asn) both in exon 13.

Synthesis, antimicrobial evaluation and docking studies of some novel quinazolinone Schiff base derivatives

PubMed Central

Nasab, Rezvan Rezaee; Mansourian, Mahboubeh; Hassanzadeh, Farshid

2018-01-01

The quinazolin-4(3H)-one structural motif possesses a wide spectrum of biological activities. DNA gyrase play an important role in induction of bacterial death. It has been shown that many quinazolin-4(3H)-one derivatives have antibacterial effects through inhibition of DNA gyrase. Based on this information we decided to synthesize novel quinazolinone Schiff base derivatives in order to evaluate their antibacterial effects. A series of novel quinazolinone Schiff base derivatives were designed and synthesized from benzoic acid. The potential DNA gyrase inhibitory activity of these compounds was investigated using in silico molecular docking simulation. All new synthesized derivatives were screened for their antimicrobial activities against three species of Gram-negative bacteria including Escherichia coli, Pseudomonas aeruginosa, Salmonella entritidis and three species of Gram-positive bacteria comprising of Staphylococcus aurous, Bacillus subtilis, Listeria monocitogenes as well as for antifungal activities against Candida albicans using the conventional micro dilution method. Most of the compounds have shown good antibacterial activities, especially against E. coli at 128 µg/mL concentration while no remarkable antifungal activities were observed for these compounds. All the synthesized compounds exhibit dock score values between -5.96 and -8.58 kcal/mol. The highest dock score among them was -8.58 kcal/mol for compound 4c. PMID:29853931

Synthesis and spectral characterization of trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes with Schiff bases.

PubMed

Singh, Atresh Kumar; Singh, Alok Kumar

2012-10-01

Some novel trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes of the general formula [Fe(3)O(OOCR)(3)(SB)(3)L(3)] (where R=C(13)H(27), C(15)H(31) or C(17)H(35,) HSB=Schiff bases and L=Ethanol) have been synthesized by the stepwise substitutions of acetate ions from μ(3)-oxo-hexa(acetato)tri(aqua)iron(II)diiron(III), first with straight chain carboxylic acids and then with Schiff bases. The complexes were characterized by elemental analyses, molecular weight determinations and spectral (electronic, infrared, FAB mass, Mössbauer and powder XRD) studies. Molar conductance measurements indicated the complexes to be non-electrolytes in nitrobenzene. Bridging nature of carboxylate and Schiff base anions in the complexes was established by their infrared spectra. Mössbauer spectroscopic studies indicated two quadrupole-split doublets due to Fe(II) and Fe(III) ions at 80, 200 and 295K, confirming the complexes are mixed-valence species. This was also supported by the observed electronic spectra of the complexes. Magnetic susceptibility measurements displayed octahedral geometry around iron in mixed-valence state and a net antiferromagnetic exchange coupling via μ-oxo atom. Trinuclear nature of the complexes was confirmed by their molecular weight determination and FAB mass spectra. A plausible structure for these complexes has been established on the basis of spectral and magnetic moment data. Copyright © 2012 Elsevier B.V. All rights reserved.

2-Phenylacetylenesulfonamide (PAS) induces p53-independent apoptotic killing of B-chronic lymphocytic leukemia (CLL) cells.

PubMed

Steele, Andrew J; Prentice, Archibald G; Hoffbrand, A Victor; Yogashangary, Birunthini C; Hart, Stephen M; Lowdell, Mark W; Samuel, Edward R; North, Janet M; Nacheva, Elisabeth P; Chanalaris, Anastasios; Kottaridis, Panagiotis; Cwynarski, Kate; Wickremasinghe, R Gitendra

2009-08-06

We studied the actions of 2-phenylacetylenesulfonamide (PAS) on B-chronic lymphocytic leukemia (CLL) cells. PAS (5-20 microM) initiated apoptosis within 24 hours, with maximal death at 48 hours asassessed by morphology, cleavage of poly(ADP-ribose) polymerase (PARP), caspase 3 activation, and annexin V staining. PAS treatment induced Bax proapoptotic conformational change, Bax movement from the cytosol to the mitochondria, and cytochrome c release, indicating that PAS induced apoptosis via the mitochondrial pathway. PAS induced approximately 3-fold up-regulation of proapoptotic Noxa protein and mRNA levels. In addition, Noxa was found unexpectedly to be bound to Bcl-2 in PAS-treated cells. PAS treatment of CLL cells failed to up-regulate p53, suggesting that PAS induced apoptosis independently of p53. Furthermore, PAS induced apoptosis in CLL isolates with p53 gene deletion in more than 97% of cells. Normal B lymphocytes were as sensitive to PAS-induced Noxa up-regulation and apoptosis as were CLL cells. However, both T lymphocytes and bone marrow hematopoietic progenitor cells were relatively resistant to PAS. Our data suggest that PAS may represent a novel class of drug that induces apoptosis in CLL cells independently of p53 status by a mechanism involving Noxa up-regulation.

Schiff base metal derivatives enhance the expression of HSP70 and suppress BAX proteins in prevention of acute gastric lesion.

PubMed

Golbabapour, Shahram; Gwaram, Nura Suleiman; Al-Obaidi, Mazen M Jamil; Soleimani, A F; Ali, Hapipah Mohd; Abdul Majid, Nazia

2013-01-01

Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP) 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg), the positive control (Tween 20 5% v/v, 5 mL/kg), and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg). After 1 h, all of the groups received ethanol 95% (5 mL/kg) but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg). The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E), immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.

Schiff Base Metal Derivatives Enhance the Expression of HSP70 and Suppress BAX Proteins in Prevention of Acute Gastric Lesion

PubMed Central

Gwaram, Nura Suleiman; Al-Obaidi, Mazen M. Jamil; Soleimani, A. F.; Ali, Hapipah Mohd; Abdul Majid, Nazia

2013-01-01

Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP) 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg), the positive control (Tween 20 5% v/v, 5 mL/kg), and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg). After 1 h, all of the groups received ethanol 95% (5 mL/kg) but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg). The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E), immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats. PMID:24298554

Effect of vagal stimulation on gastric mucosal barrier in albino rats.

PubMed

Somasundaram, K; Ganguly, A K

1987-01-01

To study the influence of vagus nerves on gastric mucosal barrier in albino rats, gastric adherent mucus and mucosal epithelial neutral glycoproteins were quantitatively assessed after vagal stimulation at the cardio-esophageal region by a specially designed circular electrode. Gastric adherent mucus and epithelial mucus were studied from oxyntic and pyloric gland areas by Alcian blue binding and periodic acid Schiff's (PAS) staining method respectively. The results when compared with sham operated control animals showed increase in the visible mucus concurrent with decrease in PAS positive materials. The stimulation at the cardio-esophageal region of vagotomized animals did not produce these effects. This study indicates that in an acute condition, increased vagal influence is important in increasing mucus secretion and strengthening the first line of defence of the mucosal barrier.

Synthesis, characterization of α-amino acid Schiff base derived Ru/Pt complexes: Induces cytotoxicity in HepG2 cell via protein binding and ROS generation

NASA Astrophysics Data System (ADS)

Alsalme, Ali; Laeeq, Sameen; Dwivedi, Sourabh; Khan, Mohd. Shahnawaz; Al Farhan, Khalid; Musarrat, Javed; Khan, Rais Ahmad

2016-06-01

We have synthesized two new complexes of platinum (1) and ruthenium (2) with α-amino acid, L-alanine, and 2,3-dihydroxybenzaldehyde derived Schiff base (L). The ligand and both complexes were characterized by using elemental analysis and several other spectroscopic techniques viz; IR, 1H, 13C NMR, EPR, and ESI-MS. Furthermore, the protein-binding ability of synthesized complexes was monitored by UV-visible, fluorescence and circular dichroism techniques with a model protein, human serum albumin (HSA). Both the PtL2 and RuL2 complexes displayed significant binding towards HSA. Also, in vitro cytotoxicity assay for both complexes was carried out on human hepatocellular carcinoma cancer (HepG2) cell line. The results showed concentration-dependent inhibition of cell viability. Moreover, the generation of reactive oxygen species was also evaluated, and results exhibited substantial role in cytotoxicity.

Synthesis, characterization and biological activity of C6-Schiff bases derivatives of chitosan.

PubMed

Xu, Ruibo; Aotegen, Bayaer; Zhong, Zhimei

2017-12-01

C 6 -Schiff bases derivatives of chitosan were synthesized for the first time. C 2 -amino groups and C 3 -hydroxy groups were firstly protected by CuSO 4 ·5H 2 O, and the C 6 -hydroxy was then transformed into aldehyde, which then reacted with anilines through nucleophilic addition to introduce the CN group at C 6 -position in chitosan chain. Finally, C 6 -Schiff bases derivatives of chitosan were got by the deprotection of C 2 -NH 2 with cation exchange resin. The structures and properties of the new synthesized products were characterized by Fourier transform infrared spectroscopy, 13 C NMR, SEM image, and elemental analysis. The antibacterial activities of derivatives were tested in the experiment, and the results showed that the prepared chitosan derivatives had significantly improved antibacterial activity toward Staphylococcus aureus and Escherichia coli. The Cytotoxicity test showed that the prepared chitosan derivatives had low Cytotoxicity, compared with chitosan and C 2 -benzaldehyde Schiff bases of chitosan. This paper allowed a new method for the synthesis of Schiff bases of chitosan, which was enlightening. Copyright © 2017 Elsevier B.V. All rights reserved.

Spectroscopic characterization, antimicrobial activity, DFT computation and docking studies of sulfonamide Schiff bases

NASA Astrophysics Data System (ADS)

Mondal, Sudipa; Mandal, Santi M.; Mondal, Tapan Kumar; Sinha, Chittaranjan

2017-01-01

Schiff bases synthesised from the condensation of 2-(hydroxy)naphthaldehyde and sulfonamides (sufathiazole (STZ), sulfapyridine (SPY), sulfadiazine (SDZ), sulfamerazine (SMZ) and sulfaguanidine (SGN)) are characterized by different spectroscopic data (FTIR, UV-Vis, Mass, NMR) and two of them, (E)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)-N-(thiazol-2-yl)benzenesulfonamide (1a) and (E)-N-(diaminomethylene)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)benzenesulfonamide (1e) have been confirmed by single crystal X-ray structure determination. Antimicrobial activities of the Schiff bases have been evaluated against certified and resistant Gram positive (Staphylococcus aureus, Enterococcus facelis) and Gram negative (Streptococcus pyogenes, Salmonella typhi, Shigella dysenteriae, Shigella flexneri, Klebsiella pneumonia) pathogens. Performance of Schiff base against the resistant pathogens are better than standard stain and MIC data lie 32-128 μg/ml while parent sulfonamides are effectively inactive (MIC >512 μg/ml). The DFT optimized structures of the Schiff bases have been used to accomplish molecular docking studies with DHPS (dihydropteroate synthase) protein structure (downloaded from Protein Data Bank) to establish the most preferred mode of interaction. ADMET filtration, Cytotoxicity (MTT assay) and haemolysis assay have been examined for evaluation of druglike character.

Changes at the KinA PAS-A Dimerization Interface Influence Histidine Kinase Function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, James; Tomchick, Diana R.; Brautigam, Chad A.

2008-11-12

The Bacillus subtilis KinA protein is a histidine protein kinase that controls the commitment of this organism to sporulate in response to nutrient deprivation and several other conditions. Prior studies indicated that the N-terminal Per-ARNT-Sim domain (PAS-A) plays a critical role in the catalytic activity of this enzyme, as demonstrated by the significant decrease of the autophosphorylation rate of a KinA protein lacking this domain. On the basis of the environmental sensing role played by PAS domains in a wide range of proteins, including other bacterial sensor kinases, it has been suggested that the PAS-A domain plays an important regulatorymore » role in KinA function. We have investigated this potential by using a combination of biophysical and biochemical methods to examine PAS-A structure and function, both in isolation and within the intact protein. Here, we present the X-ray crystal structure of the KinA PAS-A domain, showing that it crystallizes as a homodimer using {beta}-sheet/{beta}-sheet packing interactions as observed for several other PAS domain complexes. Notably, we observed two dimers with tertiary and quaternary structure differences in the crystalline lattice, indicating significant structural flexibility in these domains. To confirm that KinA PAS-A also forms dimers in solution, we used a combination of NMR spectroscopy, gel filtration chromatography, and analytical ultracentrifugation, the results of which are all consistent with the crystallographic results. We experimentally tested the importance of several residues at the dimer interface using site-directed mutagenesis, finding changes in the PAS-A domain that significantly alter KinA enzymatic activity in vitro and in vivo. These results support the importance of PAS domains within KinA and other histidine kinases and suggest possible routes for natural or artificial regulation of kinase activity.« less

Personal Assistance Services (PAS): Toward Universal Access to Support. Annotated Bibliography.

ERIC Educational Resources Information Center

Racino, Julie Ann

This annotated bibliography provides approximately 100 summaries and evaluations of documents, published from 1979 to 1995, on personal assistance services (PAS) for individuals with disabilities. Studies and articles were selected for inclusion based upon their capacity to inform the development of PAS models, including conceptual, policy, and…

PAs: Fifty years young.

PubMed

Mandel, Ellen D; North, Shannon

2017-10-01

The PA profession is 50 years young. Practicing PAs and current students hail from several generational categories ranging from Builders to Generation Z. This article reviews how different generations may have experienced PA program expansion, professional identity, state licensing, and prescription delegation. The authors sampled a cohort of PA program applicants about their views on what evokes optimism and concern for the PA profession. These themes mirror the recently paved professional road, while posing the all-important question: What construction lies on the horizon?

Digital radiography using amorphous selenium: photoconductively activated switch (PAS) readout system.

PubMed

Reznik, Nikita; Komljenovic, Philip T; Germann, Stephen; Rowlands, John A

2008-03-01

A new amorphous selenium (a-Se) digital radiography detector is introduced. The proposed detector generates a charge image in the a-Se layer in a conventional manner, which is stored on electrode pixels at the surface of the a-Se layer. A novel method, called photoconductively activated switch (PAS), is used to read out the latent x-ray charge image. The PAS readout method uses lateral photoconduction at the a-Se surface which is a revolutionary modification of the bulk photoinduced discharge (PID) methods. The PAS method addresses and eliminates the fundamental weaknesses of the PID methods--long readout times and high readout noise--while maintaining the structural simplicity and high resolution for which PID optical readout systems are noted. The photoconduction properties of the a-Se surface were investigated and the geometrical design for the electrode pixels for a PAS radiography system was determined. This design was implemented in a single pixel PAS evaluation system. The results show that the PAS x-ray induced output charge signal was reproducible and depended linearly on the x-ray exposure in the diagnostic exposure range. Furthermore, the readout was reasonably rapid (10 ms for pixel discharge). The proposed detector allows readout of half a pixel row at a time (odd pixels followed by even pixels), thus permitting the readout of a complete image in 30 s for a 40 cm x 40 cm detector with the potential of reducing that time by using greater readout light intensity. This demonstrates that a-Se based x-ray detectors using photoconductively activated switches could form a basis for a practical integrated digital radiography system.

Synthesis and optical characterization of novel carbazole Schiff bases

NASA Astrophysics Data System (ADS)

Çiçek, Baki; Çalışır, Ümit; Tavaslı, Mustafa; Tülek, Remziye; Teke, Ali

2018-02-01

In this study, newly substituted carbazole derivatives of S1; (Z)-4-((9-isobutyl-9H-carbazol-3-ylimino)methyl)phenol, S2; (Z)-9-butyl- N-(2,3,4-trimethoxybenzylidine)-9H-carbazol-3-amine, S3; (Z)-4-((9-octyl-9H-carbazol-3-ylimino)methyl)benzene-1,2-diol and S4; (Z)-3-((9-octyl-9H-carbazol-3-ylimino)methyl)benzene-1,2-diol compounds are synthesized by using condensation reaction between carbazole amines and aromatic aldehydes. All synthesized carbazole Schiff bases are purified by crystallizing from chloroform. The structural and optical characterizations of synthesized compounds are investigated by FT-IR (Fourier Transform-Infrared Spectroscopy), 1H NMR (Proton Nuclear Magnetic Resonance), 13C NMR (Carbon Nuclear Magnetic Resonance), LC-MS (Liquid Chromatography-Mass Spectrometry) and temperature dependent PL (Photoluminescence) measurements. The formations of synthesized Schiff bases were confirmed by FT-IR, NMR and microanalysis. Due to stronger π-conjugation and efficient charge transfer from host material, the broad and complex bands centered at about ∼2.16 and ∼1.76 eV are observed in PL spectra for all samples. Their relative intensities depend on functional groups associated with the carbazole. These newly synthesized Schiff bases could be considered as an active emissive layer for organic light emitting diodes.

Photophysical properties of Schiff's bases from 3-(1,3-benzothiazol-2-yl)-2-hydroxy naphthalene-1-carbaldehyde.

PubMed

Satam, Manjaree A; Telore, Rahul D; Sekar, Nagaiyan

2014-11-11

A series of novel Schiff's bases have been synthesized from 3-(1,3-benzothiazol-2-yl)-2-hydroxynaphthalene-1-carbaldehyde. The presence of hydroxyl group ortho to the benzothiazolyl group as well as the imine linkage lead to the occurrence of excited state intramolecular proton transfer process. The computational strategy was used to study the ESIPT process of the synthesized Schiff's bases, which revealed surprisingly that the keto form predominantly exists in the ground state contradicting the ESIPT process. Density functional theory and time dependent density functional theory have been used to investigate the structural parameters and photophysical properties in different solvents of one of the Schiff's bases. The experimental results correlate well with the computed results. All Schiff's bases show good thermal stability. Copyright © 2014 Elsevier B.V. All rights reserved.

Heterocyclic Schiff bases as non toxic antioxidants: Solvent effect, structure activity relationship and mechanism of action

NASA Astrophysics Data System (ADS)

Shanty, Angamaly Antony; Mohanan, Puzhavoorparambil Velayudhan

2018-03-01

Phenolic heterocyclic imine based Schiff bases from Thiophene-2-carboxaldehyde and Pyrrole-2-carboxaldehyde were synthesized and characterized as novel antioxidants. The solvent effects of these Schiff bases were determined and compared with standard antioxidants, BHA employing DPPH assay and ABTS assay. Fixed reaction time and Steady state measurement were used for study. IC50 and EC50 were calculated. Structure-activity relationship revealed that the electron donating group in the phenolic ring increases the activity where as the electron withdrawing moiety decreases the activity. The Schiff base derivatives showed antioxidant property by two different pathways namely SPLET and HAT mechanisms in DPPH assay. While in ABTS method, the reaction between ABTS radical and Schiff bases involves electron transfer followed by proton transfer (ET-PT) mechanism. The cytotoxicity of these compounds has been evaluated by MTT assay. The results showed that all these compounds are non toxic in nature.

Synthesis, characterization, X-ray crystallography, acetyl cholinesterase inhibition and antioxidant activities of some novel ketone derivatives of gallic hydrazide-derived Schiff bases.

PubMed

Gwaram, Nura Suleiman; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen; Buckle, Michael J C; Sukumaran, Sri Devi; Chung, Lip Yong; Othman, Rozana; Alhadi, Abeer A; Yehye, Wageeh A; Hadi, A Hamid A; Hassandarvish, Pouya; Khaledi, Hamid; Abdelwahab, Siddig Ibrahim

2012-02-28

Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 μM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.

Extravehicular Activity (EVA) Power, Avionics, and Software (PAS) 101

NASA Technical Reports Server (NTRS)

Irimies, David

2011-01-01

EVA systems consist of a spacesuit or garment, a PLSS, a PAS system, and spacesuit interface hardware. The PAS system is responsible for providing power for the suit, communication of several types of data between the suit and other mission assets, avionics hardware to perform numerous data display and processing functions, and information systems that provide crewmembers data to perform their tasks with more autonomy and efficiency. Irimies discussed how technology development efforts have advanced the state-of-the-art in these areas and shared technology development challenges.

Synthesis, structure elucidation, biological screening, molecular modeling and DNA binding of some Cu(II) chelates incorporating imines derived from amino acids

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; Abu-Dief, Ahmed M.; Ismael, Mohammed; Mohamed, Mounir A. A.; Hashem, Nahla Ali

2016-01-01

Three tridentate Schiff bases amino acids were prepared by direct condensation of 3-methoxysalicylaldehyde (MS) or 4-diethylaminosalicylaldehyde (DS) with α-amino acid ligands [L-phenylalanine (P), L-histidine (H) and DL-tryptophan (T)]. The prepared Schiff bases amino acids were investigated by melting points, elemental analysis, 1HNMR and 13CNMR, IR, UV-Vis spectra, conductivity and magnetic measurements analyses. Subsequently, copper was introduced and Cu(II) complexes formed. These complexes were analyzed by thermal and elemental analyses and further investigated by FT-IR and UV/Vis spectroscopies. The experimental results indicating that all Cu(II) complexes contain hydrated water molecules (except DSPCu complex) and don't contain coordinated water molecules. The kinetic and thermal parameters were extracted from the thermal data using Coast and Redfern method. The molar conductance values of the Schiff base amino acid ligands and their Cu(II) complexes were relatively low, showing that these compounds have non-electrolytic nature. Magnetic susceptibility measurements showed the diamagnetic nature of the Schiff base amino acid ligands and paramagnetic nature of their complexes. Additionally, a spectrophotometric method was determined to extract their stability constants. It was found that the complexes possess 1:2 (M:L) stoichiometry. The results suggested that 3-methoxysalicylaldehyde and 4-diethylaminosalicylaldehyde amino acid Schiff bases behave as monobasic tridentate ONO ligands and coordinate Cu(II) ions in octahedral geometry according to the general formula [Cu(HL)2]·nH2O. To further understanding the structural and electronic properties of these complexes, Density Functional Theory (DFT) calculations were employed and provided a satisfactory description. The optimized structures of MST Schiff base ligand and its complex were calculated using DFT. The antimicrobial activity of the Schiff base ligands and their complexes were screened against some

Kinetics of acid hydrolysis and reactivity of some antibacterial hydrophilic iron(II) imino-complexes

NASA Astrophysics Data System (ADS)

Shaker, Ali Mohamed; Nassr, Lobna Abdel-Mohsen Ebaid; Adam, Mohamed Shaker Saied; Mohamed, Ibrahim Mohamed Abdelhalim

2015-05-01

Kinetic study of acid hydrolysis of some hydrophilic Fe(II) Schiff base amino acid complexes with antibacterial properties was performed using spectrophotometry. The Schiff base ligands were derived from sodium 2-hydroxybenzaldehyde-5-sulfonate and glycine, L-alanine, L-leucine, L-isoleucine, DL-methionine, DL-serine, or L-phenylalanine. The reaction was studied in aqueous media under conditions of pseudo-first order kinetics. Moreover, the acid hydrolysis was studied at different temperatures and the activation parameters were calculated. The general rate equation was suggested as follows: rate = k obs [Complex], where k obs = k 2 [H+]. The evaluated rate constants and activation parameters are consistent with the hydrophilicity of the investigated complexes.

Synthesis and Evaluation of In Vitro Antibacterial and Antitumor Activities of Novel N,N-Disubstituted Schiff Bases

PubMed Central

Luo, Heng; Xia, Yu-fen; Sun, Bao-fei; Huang, Li-rong; Wang, Xing-hui; Lou, Hua-yong; Zhu, Xu-hui

2017-01-01

To get inside the properties of N,N-disubstituted Schiff bases, we synthesized three high-yielding benzaldehyde Schiff bases. We used the reaction between salicylaldehyde and different diamine compounds, including diamine, ethanediamine, and o-phenylenediamine, determining the structure of obtained molecules by nuclear magnetic resonance spectroscopy and electrospray ionization mass spectroscopy. We thus evaluated the microbicidal and antitumor activity of these compounds, showing that salicylaldehyde-hydrazine hydrate Schiff base (compound 1a) significantly inhibited the growth of S. aureus; salicylaldehyde-o-phenylenediamine Schiff base (compound 1c) displayed a strong capability to inhibit the proliferation of leukemia cell lines K562 and HEL. Moreover, we observed that the antibacterial action of 1a might be associated with the regulation of the expression of key virulence genes in S. aureus. Compound 1c resulted in a strong apoptotic activity against leukemia cells, also affecting the cell cycle distribution. Overall, our novel N,N-disubstituted Schiff bases possess unique antibacterial or antitumor activities that exhibit the potent application prospect in prophylactic or therapeutic interventions, providing new insights for developing new antibacterial and anticancer chemical agents. PMID:28713593

Crystal structure characterization as well as theoretical study of spectroscopic properties of novel Schiff bases containing pyrazole group.

PubMed

Guo, Jia; Ren, Tiegang; Zhang, Jinglai; Li, Guihui; Li, Weijie; Yang, Lirong

2012-09-01

A series of novel Schiff bases containing pyrazole group were synthesized using 1-aryl-3-methyl-4-benzoyl-5-pyrazolone and phenylenediamine as the starting materials. All as-synthesized Schiff bases were characterized by means of NMR, FT-IR, and MS; and the molecular geometries of two Schiff bases as typical examples were determined by means of single crystal X-ray diffraction. In the meantime, the ultraviolet-visible light absorption spectra and fluorescent spectra of various as-synthesized products were also measured. Moreover, the B3LYP/6-1G(d,p) method was used for the optimization of the ground state geometry of the Schiff bases; and the spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVTZ basis set of TD-B3LYP method. It has been found that all as-synthesized Schiff bases show a remarkable absorption peak in a wavelength range of 270-370 nm; and their maximum emission peaks are around 344 nm and 332 nm, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

Complex and dynamic landscape of RNA polyadenylation revealed by PAS-Seq

PubMed Central

Shepard, Peter J.; Choi, Eun-A; Lu, Jente; Flanagan, Lisa A.; Hertel, Klemens J.; Shi, Yongsheng

2011-01-01

Alternative polyadenylation (APA) of mRNAs has emerged as an important mechanism for post-transcriptional gene regulation in higher eukaryotes. Although microarrays have recently been used to characterize APA globally, they have a number of serious limitations that prevents comprehensive and highly quantitative analysis. To better characterize APA and its regulation, we have developed a deep sequencing-based method called Poly(A) Site Sequencing (PAS-Seq) for quantitatively profiling RNA polyadenylation at the transcriptome level. PAS-Seq not only accurately and comprehensively identifies poly(A) junctions in mRNAs and noncoding RNAs, but also provides quantitative information on the relative abundance of polyadenylated RNAs. PAS-Seq analyses of human and mouse transcriptomes showed that 40%–50% of all expressed genes produce alternatively polyadenylated mRNAs. Furthermore, our study detected evolutionarily conserved polyadenylation of histone mRNAs and revealed novel features of mitochondrial RNA polyadenylation. Finally, PAS-Seq analyses of mouse embryonic stem (ES) cells, neural stem/progenitor (NSP) cells, and neurons not only identified more poly(A) sites than what was found in the entire mouse EST database, but also detected significant changes in the global APA profile that lead to lengthening of 3′ untranslated regions (UTR) in many mRNAs during stem cell differentiation. Together, our PAS-Seq analyses revealed a complex landscape of RNA polyadenylation in mammalian cells and the dynamic regulation of APA during stem cell differentiation. PMID:21343387

Synthesis, characterization, spectroscopic studies and antimicrobial activity of three new Schiff bases derived from Heterocyclic moiety

NASA Astrophysics Data System (ADS)

Mesbah, Mounira; Douadi, Tahar; Sahli, Farida; Issaadi, Saifi; Boukazoula, Soraya; Chafaa, Salah

2018-01-01

Three new Schiff-bases compounds (I-III) were synthesized by a condensation reaction in 1:2 M ratios of 4,4‧-diaminodiphenyl sulfide and pyrrol/thiophene/furan-2-carboxaldehyde in ethanol. The structural determinations of the Schiff-bases were identified with the help of elemental analysis then confirmed by UV-Vis, FT-IR and 1H NMR. The products were obtained in excellent yields. On the other hand, the in vitro antibacterial and antifungal activities of the synthesized compounds were investigated using disc diffusion method. Schiff bases synthesized individually exhibited varying degrees of inhibitory effects on the growth of the tested microbial species.

Synthesis, characterization and biological studies of Schiff bases derived from heterocyclic moiety.

PubMed

Shanty, Angamaly Antony; Philip, Jessica Elizabeth; Sneha, Eeettinilkunnathil Jose; Prathapachandra Kurup, Maliyeckal R; Balachandran, Sreedharannair; Mohanan, Puzhavoorparambil Velayudhan

2017-02-01

Some new Schiff bases (H 1 -H 7 ) have been synthesized by the condensation of 2-aminophenol, 2-amino-4-nitrophenol, 2-amino-4-methylphenol, 2-amino benzimidazole with thiophene-2-carboxaldehyde and pyrrole-2-carboxaldehyde. The structures of newly synthesized compounds were characterized by elemental analysis, FT-IR, 1 H NMR, UV-VIS, and single crystal X-ray crystallography. The in vitro antibacterial activity of the synthesized compounds has been tested against Salmonella typhi, Bacillus coagulans, Bacillus pumills, Escherichia coli, Bacillus circulans, Pseudomonas, Clostridium and Klebsilla pneumonia by disk diffusion method. The quantitative antimicrobial activity of the test compounds was evaluated using Resazurin based Microtiter Dilution Assay. Ampicillin was used as standard antibiotics. Schiff bases individually exhibited varying degrees of inhibitory effects on the growth of the tested bacterial species. The antioxidant activity of the synthesized compounds was determined by the 1,1-diphenyl-2-picrylhydrazyl(DPPH) method. IC 50 value of synthesized Schiff bases were calculated and compared with standard BHA. Copyright © 2016 Elsevier Inc. All rights reserved.

Synthesis, spectroscopic characterization, DFT optimization and biological activities of Schiff bases and their metal (II) complexes

NASA Astrophysics Data System (ADS)

Rauf, Abdur; Shah, Afzal; Munawar, Khurram Shahzad; Khan, Abdul Aziz; Abbasi, Rashda; Yameen, Muhammad Arfat; Khan, Asad Muhammad; Khan, Abdur Rahman; Qureshi, Irfan Zia; Kraatz, Heinz-Bernhard; Zia-ur-Rehman

2017-10-01

A Novel Schiff base, 3-(((4-chlorophenyl)imino)methyl)benzene-1,2-diol (HL1) was successfully synthesized along with a structurally similar Schiff base 3-(((4-bromophenyl)imino)methyl)benzene-1,2-diol (HL2). Both the Schiff bases were used to synthesize their zinc (II) and cobalt (II) complexes. These compounds were characterized by FTIR, 1H NMR, 13C NMR and elemental analysis. Metal complexes were confirmed by TGA. Crystals of Schiff bases were also characterized by X-ray analysis and experimental parameters were found in line with the theoretical parameters. Quantum mechanical approach was also used to fine useful structural parameters and to ensure the geometry of metal complexes. The photometric behaviors of all the synthesized compounds were investigated in a wide pH range using BR buffers. The appearance of isosbestic points indicated the existence of Schiff bases in more than one isomeric form. Moreover, these compounds were screened for enzyme inhibition; antibacterial, cytotoxic and in vivo antidiabetic activities and compounds were found active against one or other activity. Results indicate that ZnL22 is a good inhibitor of alkaline phosphatase enzyme and possess highest potential against diabetes, blood cholesterol level and cancer cells. This effort just provides preliminary data for some biological properties. Further investigations are required to precisely determine mechanistic pathways of their use towards drug development.

Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base

PubMed Central

Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Kadihum, Abdulhadi; Mohamad, Abu Bakar; How, Chong K.; Junaedi, Sutiana

2014-01-01

The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene) hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PD) and electrochemical frequently modulation (EFM) in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM). The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene)hydrazinecarbothioamide was also verified by scanning electron microscope (SEM). PMID:28788488

Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base.

PubMed

Al-Amiery, Ahmed A; Kadhum, Abdul Amir H; Kadihum, Abdulhadi; Mohamad, Abu Bakar; How, Chong K; Junaedi, Sutiana

2014-01-28

The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene) hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PD) and electrochemical frequently modulation (EFM) in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM). The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene)hydrazinecarbothioamide was also verified by scanning electron microscope (SEM).

Physicochemical characterization of novel Schiff bases derived from developed bacterial cellulose 2,3-dialdehyde.

PubMed

Keshk, Sherif M A S; Ramadan, Ahmed M; Bondock, Samir

2015-08-20

The synthesis of two novel Schiff's bases (cellulose-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] (5) & cellulose-2,3-bis-[(4-methylene-amino)-N-(thiazol-2-yl)-benzenesulfonamide] (6) via condensation reactions of periodate oxidized developed bacterial cellulose ODBC (2) with sulfa drugs [sulfanilamide (3) & sulfathiazole (4)] was reported. The physicochemical characterization of the condensation products was performed using FTIR, (1)H NMR, (13)C NMR spectral analyses, X-ray diffraction and DTA. The ODBC exhibited the highest degree of oxidation based on the aldehyde group number percentage (82.9%), which confirms the highest reactivity of developed bacterial cellulose [DBC (1)]. The X-ray diffractograms indicated an increase in the interplanar distance of the cellulose Schiff base (6) compared to ODBC (2) due to sulfathiazole (4) inclusion between ODBC (2) sheets corresponding to the 1 1 0 plane. In addition, the aldehyde content of Schiff base (6) was (20.8%) much lower than that of Schiff base (5) (41.5%). These results confirmed the high affinity of sulfathiazole (4) to the ODBC (2) chain, and the substantial changes in the original properties of ODBC were due to these chemical modifications rather than the sulfanilamide (3). Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis, characterization and biological assay of Salicylaldehyde Schiff base Cu(II) complexes and their precursors

NASA Astrophysics Data System (ADS)

Iftikhar, Bushra; Javed, Kanwal; Khan, Muhammad Saif Ullah; Akhter, Zareen; Mirza, Bushra; Mckee, Vickie

2018-03-01

Three new Schiff base ligands were synthesized by the reaction of Salicylaldehyde with semi-aromatic diamines, prepared by the reduction of corresponding dinitro-compounds, and were further used for the formation of complexes with Cu(II) metal ion. The structural features of the synthesized compounds were confirmed by their physical properties and infrared, electronic and NMR spectroscopic techniques. The studies revealed that the synthesized Schiff bases existed as tetradentate ligands and bonded to the metal ion through the phenolic oxygen and azomethine nitrogen. One of the dinitro precursors was also analyzed by single crystal X-ray crystallography, which showed that it crystallizes in monoclinic system with space group P2/n. The thermal behavior of the Cu(II) complexes was determined by thermogravimetric analysis (TGA) and kinetic parameters were evaluated from the data. Schiff base ligands, their precursors and metal complexes were also screened for antibacterial, antifungal, antitumor, Brine shrimp lethality, DPPH free radical scavenging and DNA damage assays. The results of these analyses indicated the substantial potential of the synthesized Schiff bases, their precursors and Cu(II) complexes in biological field as future drugs.

Synthesis, characterization and toxicity studies of pyridinecarboxaldehydes and L-tryptophan derived Schiff bases and corresponding copper (II) complexes

PubMed Central

Malakyan, Margarita; Babayan, Nelly; Grigoryan, Ruzanna; Sarkisyan, Natalya; Tonoyan, Vahan; Tadevosyan, Davit; Matosyan, Vladimir; Aroutiounian, Rouben; Arakelyan, Arsen

2016-01-01

Schiff bases and their metal-complexes are versatile compounds exhibiting a broad range of biological activities and thus actively used in the drug development process. The aim of the present study was the synthesis and characterization of new Schiff bases and their copper (II) complexes, derived from L-tryptophan and isomeric (2-; 3-; 4-) pyridinecarboxaldehydes, as well as the assessment of their toxicity in vitro. The optimal conditions of the Schiff base synthesis resulting in up to 75-85% yield of target products were identified. The structure-activity relationship analysis indicated that the location of the carboxaldehyde group at 2-, 3- or 4-position with regard to nitrogen of the pyridine ring in aldehyde component of the L-tryptophan derivative Schiff bases and corresponding copper complexes essentially change the biological activity of the compounds. The carboxaldehyde group at 2- and 4-positions leads to the higher cytotoxic activity, than that of at 3-position, and the presence of the copper in the complexes increases the cytotoxicity. Based on toxicity classification data, the compounds with non-toxic profile were identified, which can be used as new entities in the drug development process using Schiff base scaffold. PMID:28344771

Synthesis, characterization and toxicity studies of pyridinecarboxaldehydes and L-tryptophan derived Schiff bases and corresponding copper (II) complexes.

PubMed

Malakyan, Margarita; Babayan, Nelly; Grigoryan, Ruzanna; Sarkisyan, Natalya; Tonoyan, Vahan; Tadevosyan, Davit; Matosyan, Vladimir; Aroutiounian, Rouben; Arakelyan, Arsen

2016-01-01

Schiff bases and their metal-complexes are versatile compounds exhibiting a broad range of biological activities and thus actively used in the drug development process. The aim of the present study was the synthesis and characterization of new Schiff bases and their copper (II) complexes, derived from L-tryptophan and isomeric (2-; 3-; 4-) pyridinecarboxaldehydes, as well as the assessment of their toxicity in vitro . The optimal conditions of the Schiff base synthesis resulting in up to 75-85% yield of target products were identified. The structure-activity relationship analysis indicated that the location of the carboxaldehyde group at 2-, 3- or 4-position with regard to nitrogen of the pyridine ring in aldehyde component of the L-tryptophan derivative Schiff bases and corresponding copper complexes essentially change the biological activity of the compounds. The carboxaldehyde group at 2- and 4-positions leads to the higher cytotoxic activity, than that of at 3-position, and the presence of the copper in the complexes increases the cytotoxicity. Based on toxicity classification data, the compounds with non-toxic profile were identified, which can be used as new entities in the drug development process using Schiff base scaffold.

Synthesis and antibacterial activity of Schiff bases and amines derived from alkyl 2-(2-formyl-4-nitrophenoxy)alkanoates.

PubMed

Goszczyńska, Agata; Kwiecień, Halina; Fijałkowski, Karol

A series of novel Schiff bases and secondary amines were obtained in good yields, as a result of the reductive amination of alkyl 2-(2-formyl-4-nitrophenoxy)alkanoates with both aniline and 4-methoxyaniline under established mild reaction conditions. Sodium triacetoxyborohydride as well as hydrogen in the presence of palladium on carbon were used as efficient reducing agents of the Schiff bases, in both direct and stepwise reductive amination processes. The Schiff bases, amines, and amine hydrochlorides were designed as potential antibacterial agents, and structure-activity relationship could be established following in vitro assays against Gram-positive and Gram-negative bacteria. The minimal inhibitory concentration and zone of inhibition were also determined. In these tests, some of Schiff bases and secondary amine hydrochlorides showed moderate-to-good activity against Gram-positive bacteria, including S. aureus , M. luteus , and S. mutans .

Investigation of the antioxidant and radical scavenging activities of some phenolic Schiff bases with different free radicals.

PubMed

Marković, Zoran; Đorović, Jelena; Petrović, Zorica D; Petrović, Vladimir P; Simijonović, Dušica

2015-11-01

The antioxidant properties of some phenolic Schiff bases in the presence of different reactive particles such as (•)OH, (•)OOH, (CH2=CH-O-O(•)), and (-•)O2 were investigated. The thermodynamic values, ΔH BDE, ΔH IP, and ΔH PA, were used for this purpose. Three possible mechanisms for transfer of hydrogen atom, concerted proton-electron transfer (CPET), single electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) were considered. These mechanisms were tested in solvents of different polarity. On the basis of the obtained results it was shown that SET-PT antioxidant mechanism can be the dominant mechanism when Schiff bases react with radical cation, while SPLET and CPET are competitive mechanisms for radical scavenging of hydroxy radical in all solvents under investigation. Examined Schiff bases react with the peroxy radicals via SPLET mechanism in polar and nonpolar solvents. The superoxide radical anion reacts with these Schiff bases very slowly.

Bacterial growth kinetics in ACD-A apheresis platelets: comparison of plasma and PAS III storage.

PubMed

Dumont, Larry J; Wood, Tammara A; Housman, Molly; Herschel, Louise; Brantigan, Barbara; Heber, Cheryl; Houghton, Jaime

2011-05-01

Our objective was to determine the growth kinetics of bacteria in leukoreduced apheresis platelets (LR-AP) in a platelet (PLT) additive solution (PAS; InterSol, Fenwal, Inc.) compared to LR-AP stored in plasma. Hyperconcentrated, double-dose LR-AP were collected from healthy donors with a separator (AMICUS, Fenwal, Inc.). LR-AP were evenly divided, InterSol was added to half (65% InterSol:35% plasma [PAS]), and PLTs in autologous plasma were used for a paired control (PL). Bacteria were inoculated into each LR-AP PAS/PL pair (0.5-1.6 colony-forming units [CFUs]/mL), and bacterial growth was followed for up to 7 days. Time to the end of the lag phase, doubling times, maximum concentration (conc-max), and time to maximum concentration (time-max) were estimated. Streptococcus viridans did not grow to detectable levels in either PAS or PL units. The other bacteria had no significant overall difference in the conc-max (p = 0.47) or time-max (p = 0.7) between PL and PAS LR-AP; PL had a 0.14 hours faster doubling rate (p = 0.023); and PAS had a 4.7 hours shorter lag time (p = 0.016). We observed that five index organisms will grow in LR-AP stored in a 35%:65% ratio of plasma to InterSol where initial bacterial concentrations are 0.5 to 1.6 CFUs/mL. The more rapid initiation of log-phase growth for bacteria within a PAS storage environment resulted in a bacterial concentration up to 4 logs higher in the PAS units compared to the plasma units at 24 hours, but with no difference in the conc-max. This may present an early bacterial detection advantage for PAS-stored PLTs. © 2010 American Association of Blood Banks.

Supramolecular control over recognition and efficient detection of picric acid.

PubMed

Béreau, Virginie; Duhayon, Carine; Sutter, Jean-Pascal

2014-10-18

Bimetallic Schiff-base Al(3+) complexes bearing ester functions at the periphery of the ligands are shown to be efficient fluorescent chemosensors for picric acid detection. The prominent role of an association between the chemosensor and the picric acid in the detection process is demonstrated. The detection of picric acid in water is achieved with the sensor deposited on paper.

Does DSM-IV Have Equivalents for the Parental Alienation Syndrome (PAS) Diagnosis?

ERIC Educational Resources Information Center

Gardner, Richard A.

2003-01-01

Child custody evaluators commonly find themselves confronted with resistance when they attempt to use the term parental alienation syndrome (PAS) in courts of law. The purpose of this article is to elucidate the reasons for the reluctance to use the PAS diagnosis and the applicability of parental alienation, as well as current DSM-IV substitute…

In vitro antibacterial, antifungal and cytotoxic activities of some triazole Schiff bases and their oxovanadium(IV) complexes.

PubMed

Sumrra, Sajjad H; Chohan, Zahid H

2013-12-01

The condensation reaction of 3,5-diamino-1,2,4-triazole with methoxy-, chloro-, bromo-, iodo- and nitro-substituted 2-hydroxybenzaldehydes formed triazole Schiff bases (L(1))-(L(6)). The synthesized ligands have been characterized through physical, spectral and analytical data. Furthermore, the reaction of synthesized Schiff bases with the oxovanadium(IV) sulphate in (1:2) (metal:ligand) molar ratio afforded the oxovanadium(IV) complexes (1)-(6). All the complexes were non-electrolytic and showed a square-pyramidal geometry. The synthesized compounds have been screened for in-vitro antibacterial, antifungal and brine shrimp bioassay. The bioactivity data showed the complexes to be more active than the original Schiff bases.

HPLC analysis of para-aminosalicylic acid and its metabolite in plasma, cerebrospinal fluid and brain tissues

PubMed Central

Hong, Lan; Jiang, Wendy; Zheng, Wei; Zeng, Su

2011-01-01

Para-aminosalicylic acid (PAS), an approved drug for treatment of tuberculosis, is a promising therapeutic agent for treatment of manganese (Mn)-induced parkinsonian syndromes. Lack of a quantifying method, however, has hindered the clinical evaluation of its efficacy and thereupon new drug development. This study was aimed at developing a simple and effective method to quantify PAS and its major metabolite, N-acetyl-para-aminosalicylic acid (AcPAS), in plasma, cerebrospinal fluid (CSF) and tissues. Biological samples underwent one-step protein precipitation. The supernatant was fractionated on a reversed-phase C18 column with a gradient mobile system, followed by on-line fluorescence detection. The lower limits of quantification for both PAS and AcPAS were 50 ng/ml of plasma and 17 ng/g of tissues. The intra-day and inter-day precision values did not exceed 5% and 8%, respectively, in all three matrices. The method was used to quantify PAS and AcPAS in rat plasma and brain following a single iv injection of PAS. Data showed a greater amount of PAS than AcPAS in plasma, while a greater amount of AcPAS than PAS was found in brain tissues. The method has been proven to be sensitive, reproducible, and practically useful for laboratory and clinical investigations of PAS in treatment of Mn Parkinsonism. PMID:21159459

para-Aminosalicylic acid is a prodrug targeting dihydrofolate reductase in Mycobacterium tuberculosis.

PubMed

Zheng, Jun; Rubin, Eric J; Bifani, Pablo; Mathys, Vanessa; Lim, Vivian; Au, Melvin; Jang, Jichan; Nam, Jiyoun; Dick, Thomas; Walker, John R; Pethe, Kevin; Camacho, Luis R

2013-08-09

para-Aminosalicylic acid (PAS) is one of the antimycobacterial drugs currently used for multidrug-resistant tuberculosis. Although it has been in clinical use for over 60 years, its mechanism(s) of action remains elusive. Here we report that PAS is a prodrug targeting dihydrofolate reductase (DHFR) through an unusual and novel mechanism of action. We provide evidences that PAS is incorporated into the folate pathway by dihydropteroate synthase (DHPS) and dihydrofolate synthase (DHFS) to generate a hydroxyl dihydrofolate antimetabolite, which in turn inhibits DHFR enzymatic activity. Interestingly, PAS is recognized by DHPS as efficiently as its natural substrate para-amino benzoic acid. Chemical inhibition of DHPS or mutation in DHFS prevents the formation of the antimetabolite, thereby conferring resistance to PAS. In addition, we identified a bifunctional enzyme (riboflavin biosynthesis protein (RibD)), a putative functional analog of DHFR in a knock-out strain. This finding is further supported by the identification of PAS-resistant clinical isolates encoding a RibD overexpression mutation displaying cross-resistance to genuine DHFR inhibitors. Our findings reveal that a metabolite of PAS inhibits DHFR in the folate pathway. RibD was shown to act as a functional analog of DHFR, and as for DHFS, both were shown to be associated in PAS resistance in laboratory strains and clinical isolates.

Amido-Schiff base derivatives as colorimetric fluoride sensor: Effect of nitro substitution on the sensitivity and color change.

PubMed

Ghosh, Soumen; Alam, Md Akhtarul; Ganguly, Aniruddha; Guchhait, Nikhil

2015-01-01

A series of Schiff bases synthesized by the condensation of benzohydrazide and -NO2 substituted benzaldehyde have been used as selective fluoride ion sensor. Test paper coated with these synthetic Schiff bases (test kits) can detect fluoride ion selectively with a drastic color change and detection can be achieved by just using the naked-eye without the help of any optical instrument. Interestingly, the position of -NO2 group in the amido Schiff bases has an effect on the sensitivity as well as on the change of color of species. Copyright © 2015 Elsevier B.V. All rights reserved.

Schiff base-Poloxamer P85 combination demonstrates chemotherapeutic effect on prostate cancer cells in vitro.

PubMed

Demirci, Selami; Doğan, Ayşegül; Türkmen, Neşe Başak; Telci, Dilek; Rizvanov, Albert A; Şahin, Fikrettin

2017-02-01

Prostate cancer is a multistep and complicated cancer type that is regulated by androgens at the cellular level and remains the second commonest cause of death among men. Discovery and development of novel chemotherapeutic agents enabling rapid tumor cell death with minimal toxic effects to healthy tissues might greatly improve the safety of chemotherapy. The present study evaluates the anti-cancer activity of a novel heterodinuclear copper(II)Mn(II) complex (Schiff base) in combination with poly(ethylene oxide) and poly(propylene oxide) block copolymer (Pluronic) P85. We used assays for cell proliferation, apoptosis, cell migration and invasion, DNA binding and cleavage to elucidate the molecular mechanisms of action, in addition to the anti-inflammatory potency of the new combination. The combined treatment of Schiff base and P85 lead to a remarkable anti-cancer effect on prostate cancer cell lines. Cell proliferation was inhibited in Schiff base-P85 treatment. The activity of this formulation is on DNA binding and cleavage and prevents inflammation in in vitro conditions. This is the first study presenting the anti-cancer activity of the present Schiff base derivative and its combination with P85 to treat prostate cancer in vitro. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Protein changes associated with reprotonation of the Schiff base in the photocycle of Asp96-->Asn bacteriorhodopsin. The MN intermediate with unprotonated Schiff base but N-like protein structure

NASA Technical Reports Server (NTRS)

Sasaki, J.; Shichida, Y.; Lanyi, J. K.; Maeda, A.

1992-01-01

The difference Fourier transform infrared spectrum for the N intermediate in the photoreaction of the light-adapted form of bacteriorhodopsin can be recorded at pH 10 at 274 K (Pfefferle, J.-M., Maeda, A., Sasaki, J., and Yoshizawa, T. (1991) Biochemistry 30, 6548-6556). Under these conditions, Asp96-->Asn bacteriorhodopsin gives a photoproduct which shows changes in protein structure similar to those observed in N of wild-type bacteriorhodopsin. However, decreased intensity of the chromophore bands and the single absorbance maximum at about 400 nm indicate that the Schiff base is unprotonated, as in the M intermediate. This photoproduct was named MN. At pH 7, where the supply of proton is not as restricted as at pH 10, Asp96-->Asn bacteriorhodopsin yields N with a protonated Schiff base. The Asn96 residue, which cannot deprotonate as Asp96 in wild-type bacteriorhodopsin, is perturbed upon formation of both MN at pH 10 and N at pH 7. We suggest that the reprotonation of the Schiff base is preceded by a large change in the protein structure including perturbation of the residue at position 96.

New Thiazolyl-triazole Schiff Bases: Synthesis and Evaluation of the Anti-Candida Potential.

PubMed

Stana, Anca; Enache, Alexandra; Vodnar, Dan Cristian; Nastasă, Cristina; Benedec, Daniela; Ionuț, Ioana; Login, Cezar; Marc, Gabriel; Oniga, Ovidiu; Tiperciuc, Brîndușa

2016-11-22

In the context of the dangerous phenomenon of fungal resistance to the available therapies, we present here the chemical synthesis of a new series of thiazolyl-triazole Schiff bases B1 - B15 , which were in vitro assessed for their anti- Candida potential. Compound B10 was found to be more potent against Candida spp. when compared with the reference drugs Fluconazole and Ketoconazole. A docking study of the newly synthesized Schiff bases was performed, and results showed good binding affinity in the active site of co-crystallized Itraconazole-lanosterol 14α-demethylase isolated from Saccharomyces cerevisiae . An in silico ADMET (absorption, distribution, metabolism, excretion, toxicity) study was done in order to predict some pharmacokinetic and pharmacotoxicological properties. The Schiff bases showed good drug-like properties. The results of in vitro anti- Candida activity, a docking study and ADMET prediction revealed that the newly synthesized compounds have potential anti- Candida activity and evidenced the most active derivative, B10 , which can be further optimized as a lead compound.

One-step electrochemical deposition of Schiff base cobalt complex as effective water oxidation catalyst

NASA Astrophysics Data System (ADS)

Huang, Binbin; Wang, Yan; Zhan, Shuzhong; Ye, Jianshan

2017-02-01

Schiff base metal complexes have been applied in many fields, especially, a potential homogeneous catalyst for water splitting. However, the high overpotential, time consumed synthesis process and complicated working condition largely limit their application. In the present work, a one-step approach to fabricate Schiff base cobalt complex modified electrode is developed. Microrod clusters (MRC) and rough spherical particles (RSP) can be obtained on the ITO electrode through different electrochemical deposition condition. Both of the MRC and RSP present favorable activity for oxygen evolution reaction (OER) compared to the commercial Co3O4, taking an overpotential of 650 mV and 450 mV to drive appreciable catalytic current respectively. The highly active and stable RSP shows a Tafel plot of 84 mV dec-1 and negligible decrease of the current density for 12 h bulk electrolysis. The synthesis strategy of effective and stable catalyst in this work provide a simple method to fabricate heterogeneous OER catalyst with Schiff base metal complex.

Deep Eutectic Solvents as Convenient Media for Synthesis of Novel Coumarinyl Schiff Bases and Their QSAR Studies.

PubMed

Molnar, Maja; Komar, Mario; Brahmbhatt, Harshad; Babić, Jurislav; Jokić, Stela; Rastija, Vesna

2017-09-05

Deep eutectic solvents, as green and environmentally friendly media, were utilized in the synthesis of novel coumarinyl Schiff bases. Novel derivatives were synthesized from 2-((4-methyl-2-oxo-2 H -chromen-7-yl)oxy)acetohydrazide and corresponding aldehyde in choline chloride:malonic acid (1:1) based deep eutectic solvent. In these reactions, deep eutectic solvent acted as a solvent and catalyst as well. Novel Schiff bases were synthesized in high yields (65-75%) with no need for further purification, and their structures were confirmed by mass spectra, ¹H and 13 C NMR. Furthermore, their antioxidant activity was determined and compared to antioxidant activity of previously synthesized derivatives, thus investigating their structure-activity relationship utilizing quantitative structure-activity relationship QSAR studies. Calculation of molecular descriptors has been performed by DRAGON software. The best QSAR model ( R tr = 0.636; R ext = 0.709) obtained with three descriptors ( MATS3m , Mor22u , Hy ) implies that the pairs of atoms higher mass at the path length 3, three-dimensional arrangement of atoms at scattering parameter s = 21 Å - ¹, and higher number of hydrophilic groups (-OH, -NH) enhanced antioxidant activity. Electrostatic potential surface of the most active compounds showed possible regions for donation of electrons to 1,1-diphenyl-2-picryhydrazyl (DPPH) radicals.

Comparison of Short-Term Effects of Diquafosol and Rebamipide on Mucin 5AC Level on the Rabbit Ocular Surface.

PubMed

Hori, Yuichi; Kageyama, Tomofumi; Sakamoto, Asuka; Shiba, Tomoaki; Nakamura, Masatsugu; Maeno, Takatoshi

To investigate the short-term effects of 2 new secretagogue eye drops for dry eye, 3% diquafosol tetrasodium ophthalmic solution (diquafosol) and 2% rebamipide ophthalmic suspension (rebamipide), on the concentration of mucin 5AC (MUC5AC) in rabbit tear fluid and conjunctival goblet cells. One dose of artificial tears, diquafosol or rebamipide, was instilled into 8 eyes of Japanese white rabbits. MUC5AC concentration in the tear fluid was examined using the enzyme-linked immunosorbent assay 15 min after instillation and compared with 8 untreated controls. Impression cytology was performed to measure the number of periodic acid Schiff (PAS)-positive cells and the ratio of the PAS-positive area using image analysis software. Statistical comparison was performed using ANOVA with post hoc analysis with the Tukey's test. After 15 min, only diquafosol significantly (P ≤ 0.01) increased the MUC5AC level in the tear fluid. Although no drug affected the number of PAS-positive cells, the ratio of the PAS-positive area decreased significantly (P ≤ 0.01) only in the diquafosol group. These data indicated that more PAS-positive MUC5AC was released into the tear fluid from the goblet cells by diquafosol than by rebamipide. There is a difference in the induction pattern of MUC5AC into the tears from the goblet cells between these eye drops.

Combining protein sequence, structure, and dynamics: A novel approach for functional evolution analysis of PAS domain superfamily.

PubMed

Dong, Zheng; Zhou, Hongyu; Tao, Peng

2018-02-01

PAS domains are widespread in archaea, bacteria, and eukaryota, and play important roles in various functions. In this study, we aim to explore functional evolutionary relationship among proteins in the PAS domain superfamily in view of the sequence-structure-dynamics-function relationship. We collected protein sequences and crystal structure data from RCSB Protein Data Bank of the PAS domain superfamily belonging to three biological functions (nucleotide binding, photoreceptor activity, and transferase activity). Protein sequences were aligned and then used to select sequence-conserved residues and build phylogenetic tree. Three-dimensional structure alignment was also applied to obtain structure-conserved residues. The protein dynamics were analyzed using elastic network model (ENM) and validated by molecular dynamics (MD) simulation. The result showed that the proteins with same function could be grouped by sequence similarity, and proteins in different functional groups displayed statistically significant difference in their vibrational patterns. Interestingly, in all three functional groups, conserved amino acid residues identified by sequence and structure conservation analysis generally have a lower fluctuation than other residues. In addition, the fluctuation of conserved residues in each biological function group was strongly correlated with the corresponding biological function. This research suggested a direct connection in which the protein sequences were related to various functions through structural dynamics. This is a new attempt to delineate functional evolution of proteins using the integrated information of sequence, structure, and dynamics. © 2017 The Protein Society.

Epitaxial nanowire formation in metamorphic GaAs/GaPAs short-period superlattices

NASA Astrophysics Data System (ADS)

Zheng, Nan; Ahrenkiel, S. Phillip

2017-07-01

Metamorphic growth presents routes to novel nanomaterials with unique properties that may be suitable for a range of applications. We discuss self-assembled, epitaxial nanowires formed during metalorganic chemical vapor deposition of metamorphic GaAs/GaPAs short-period superlattices. The heterostructures incorporate strain-engineered GaPAs compositional grades on 6°-<111>B miscut GaAs substrates. Lateral diffusion within the SPS into vertically aligned, three-dimensional columns results in nanowires extending along <110>A directions with a lateral period of 70-90 nm. The microstructure is probed by transmission electron microscopy to confirm the presence of coherent GaAs nanowires within GaPAs barriers. The compositional profile is inferred from analysis of {200} dark-field image contrast and <210> lattice images.

Mixed (phthalocyaninato)(Schiff-base) di-dysprosium sandwich complexes. Effect of magnetic coupling on the SMM behavior.

PubMed

Wang, Hailong; Liu, Chenxi; Liu, Tao; Zeng, Suyuan; Cao, Wei; Ma, Qi; Duan, Chunying; Dou, Jianmin; Jiang, Jianzhuang

2013-11-21

Reaction between Schiff-base ligand and half-sandwich complex M(Pc)(acac) led to the isolation of new sandwich-type mixed (phthalocyaninato)(Schiff-base) di-lanthanide compounds M2(Pc)2(L)H2O (M = Dy, Gd) (1, 2) [H2Pc = metal free phthalocyanine, Hacac = acetylacetone, H2L = N,N'-bis(3-methyloxysalicylidene)benzene-1,2-diamine] with the triple-decker molecular structure clearly revealed by single crystal X-ray diffraction analysis. For the comparative studies, sandwich triple-decker analogues with pure Schiff-base ligand M2(L)3H2O (M = Dy, Gd) (3, 4) were also prepared. Dynamic magnetic measurement result reveals the single-molecule magnet (SMM) nature of the di-dysprosium derivative 1, while the static magnetic investigation over both pure and the diamagnetic diluted samples of this compound discloses the interionic ferromagnetic coupling between the two dysprosium ions, which in turn effectively suppresses the QTM and enhances the energy barrier of this SMM. Nevertheless, comparative studies over the static magnetic properties of the di-dysprosium triple-decker complexes 1 and 3 indicate the stronger magnetic coupling between the two lanthanide ions in mixed (phthalocyaninato)(Schiff-base) species than in the pure Schiff-base triple-decker analogue, suggesting the special coordination sphere around the dysprosium ions in the former compound over the latter one on the more intense inter-ionic ferromagnetic coupling. As a very small step towards understanding the structure-property relationship, the present result will be surely helpful for the design and synthesis of the multinuclear lanthanide-based SMMs with good properties.

Establishment of a hepatocyte line for studying biosynthesis of long-chain polyunsaturated fatty acids from a marine teleost, the white-spotted spinefoot Siganus canaliculatus.

PubMed

Liu, Y; Zhang, Q H; Dong, Y W; You, C H; Wang, S Q; Li, Y Q; Li, Y Y

2017-08-01

A hepatocyte line was established from the liver of white-spotted spinefoot Siganus canaliculatus to study the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA). The cells from the line, designated S. canaliculatus hepatocyte line (SCHL), grew and multiplied well in Dulbecco's modified Eagle's medium (DMEM)-F12 medium supplemented with 20 mM 4-(2-hydroxyethyl) piperazine-1-ethanesulphonic acid (HEPES), 10% foetal bovine serum (FBS) and 0·5% rainbow trout Oncorhychus mykiss serum at 28° C, showing an epithelial-like morphology and the normal chromosome number of 48 (2n) and have been subcultured for over 60 passages. The identity of the hepatocytes was confirmed by periodic acid Schiff (PAS) staining. The mRNA expression of all genes encoding the key enzymes for LC-PUFA biosynthesis including two desaturases (Δ4 Fad and Δ6-Δ5 Fad) and two elongases (Elovl4 and Elovl5), were detected in all cells from passages 5 to 60 and their expression levels became stable after passage 35 and showed responses to various PUFA incubation. This is similar to the situation determined in the liver of S. canaliculatus that were fed diets containing different fatty acids. These results indicated that SCHL was successfully established and can provide an in vitro tool to investigate lipid metabolism and regulatory mechanisms of LC-PUFA biosynthesis in teleosts, especially marine species. © 2017 The Fisheries Society of the British Isles.

Synthesis, characterization, and biological evaluation of Schiff base-platinum(II) complexes

NASA Astrophysics Data System (ADS)

Shiju, C.; Arish, D.; Bhuvanesh, N.; Kumaresan, S.

2015-06-01

The platinum complexes of Schiff base ligands derived from 4-aminoantipyrine and a few substituted aldehydes were synthesized and characterized by elemental analysis, mass, 1H NMR, IR, electronic spectra, molar conductance, and powder XRD. The structure of one of the ligands L5 was confirmed by a single crystal XRD analysis. The Schiff base ligand crystallized in the triclinic, space group P-1 with a = 7.032(2) Ǻ, b = 9.479(3) Ǻ, c = 12.425(4) Ǻ, α = 101.636(3)°, β = 99.633(3)°, γ = 94.040(3)°, V = 795.0(4) Ǻ3, Z = 2, F(0 0 0) = 352, Dc = 1.405 mg/m3, μ = 0.099 mm-1, R = 0.0378, and wR = 0.0967. The spectral results show that the Schiff base ligand acts as a bidentate donor coordinating through the azomethine nitrogen and the carbonyl oxygen atoms. The geometrical structures of these complexes are found to be square planar. Antimicrobial studies indicate that these complexes exhibit better activity than the ligand. The anticancer activities of the complexes have also been studied towards human cervical cancer cell line (HeLa), Colon Cancer Cells (HCT116) and Epidermoid Carcinoma Cells (A431) and it was found that the [Pt(L3)Cl2] complex is more active.

In vitro anticancer activities of Schiff base and its lanthanum complex

NASA Astrophysics Data System (ADS)

Neelima; Poonia, Kavita; Siddiqui, Sahabjada; Arshad, Md; Kumar, Dinesh

2016-02-01

Schiff base metal complexes are well-known to intercalate DNA. The La(III) complexes have been synthesized such that they hinder with the role of the topoisomerases, which control the topology of DNA during the cell-division cycle. Although several promising chemotherapeutics have been developed, on the basis of Schiff base metal complex DNA intercalating system they did not proceed past clinical trials due to their dose-limiting toxicity. Herein, we discuss an alternative compound, the La(III) complex, [La(L1)2Cl3]·7H2O based on a Schiff base ligand 2,3-dihydro-1H-indolo-[2,3-b]-phenazin-4(5H)-ylidene)benzothiazole-2-amine (L1), and report in vitro cell studies. Results of antitumor activity using cell viability assay, reactive oxygen species (ROS) generation and nuclear condensation in PC-3 (Human, prostate carcinoma) cells show that the metal complex is more potent than ligand. La(III) complexes have been synthesized by reaction of lanthanum(III) salt in 1:2 M ratio with ligands L1 and 3-(ethoxymethylene)-2,3-dihydro-1H-indolo[2,3-b]-phenazin-4(5H)-ylidene)benzathiazole-2-amine (L2) in methanol. The ligands and their La(III) complexes were characterized by molar conductance, magnetic susceptibility, elemental analyses, FT-IR, UV-Vis, 1H/13C NMR, thermogravimetric, XRD, and SEM analysis.

Irreversible covalent modification of type I dehydroquinase with a stable Schiff base.

PubMed

Tizón, Lorena; Maneiro, María; Peón, Antonio; Otero, José M; Lence, Emilio; Poza, Sergio; van Raaij, Mark J; Thompson, Paul; Hawkins, Alastair R; González-Bello, Concepción

2015-01-21

The irreversible inhibition of type I dehydroquinase (DHQ1), the third enzyme of the shikimic acid pathway, is investigated by structural, biochemical and computational studies. Two epoxides, which are mimetics of the natural substrate, were designed as irreversible inhibitors of the DHQ1 enzyme and to study the binding requirements of the linkage to the enzyme. The epoxide with the S configuration caused the covalent modification of the protein whereas no reaction was obtained with its epimer. The first crystal structure of DHQ1 from Salmonella typhi covalently modified by the S epoxide, which is reported at 1.4 Å, revealed that the modified ligand is surprisingly covalently attached to the essential Lys170 by the formation of a stable Schiff base. The experimental and molecular dynamics simulation studies reported here highlight the huge importance of the conformation of the C3 carbon of the ligand for covalent linkage to this type of aldolase I enzyme, revealed the key role played by the essential His143 as a Lewis acid in this process and show the need for a neatly closed active site for catalysis.

[Parental alienation syndrome (PAS): unknown in medical settings, endemic in courts].

PubMed

Pignotti, Maria Serenella

2013-02-01

A purposed syndrome of so-called parental alienation (PAS), unsupported by any evidence-based data, unknown in medical settings, unquoted in medical books, absent in DSM and ICD, never demonstrated by controlled studies published in high scientific level journals, is rampant in Courts where it can lead to loose parental custody. During a divorce trial, almost always the mothers and the children, become joint in a sort of folie au deux, in a denigration campaign of ex-husband/father. From a review on this issue it seems evident its theoretical roots lie on a theory that justify gender violence and children sexual abuse. The bias that both of them are layers and that he children have not autonomy block their possibility of any defence in front of a Court. In severe cases, PAS becomes a new and efficient tool of intra-familiar violence. The treatment of severe cases is to stop any contact between mother and children. The resort to PAS in Courts must be strongly rejected.

Langmuir-Blodgett Films of Aromatic Schiff’s Bases Functionalized in the Side Chains of Polymethacrylate

DTIC Science & Technology

1991-05-03

Report No. 21 - Latigmuir-Blodgett Films of Aromatic Schiffs Bases , K Fuctionalized in the Side Chains of Polymethacrylate by T. Takahashi, P. Miller...aromatic Schiff’s bases functionalized in the side chains of Polymethacrylate T. Takahashi**, P. Miller*, Y. M. Chen*, L. Samuelson***, D. Galotti, B...has been investigated for polymers in which nonlinear optical (NLO) moieties are attachcd i, the side chain of polymethacrylate (PMA) backbone. Polymer

Metal based pharmacologically active agents: Synthesis, structural characterization, molecular modeling, CT-DNA binding studies and in vitro antimicrobial screening of iron(II) bromosalicylidene amino acid chelates

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.; Ismael, Mohamed; Seleem, Amin Abdou

2014-01-01

In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine (arg)). The structure of the investigated iron(II) complexes was elucidated using elemental analyses, infrared, ultraviolet-visible, thermogravimetric analysis, as well as conductivity and magnetic susceptibility measurements. Moreover, the stoichiometry and the stability constants of the prepared complexes have been determined spectrophotometrically. The results suggest that 5-bromosalicylaldehyde amino acid Schiff bases (bs:aa) behave as dibasic tridentate ONO ligands and coordinate to Fe(II) in octahedral geometry according to the general formula [Fe(bs:aa)2]ṡnH2O. The conductivity values between 37 and 64 ohm-1 mol-1 cm2 in ethanol imply the presence of nonelectrolyte species. The structure of the complexes was validated using quantum mechanics calculations based on accurate DFT methods. Geometry optimization of the Fe-Schiff base amino acid complexes showed that all complexes had octahedral coordination. In addition, the interaction of these complexes with (CT-DNA) was investigated at pH = 7.2, by using UV-vis absorption, viscosity and agarose gel electrophoresis measurements. Results indicated that the investigated complexes strongly bind to calf thymus DNA via intercalative mode and showed a different DNA binding according to the sequence: bsari > bshi > bsali > bsasi > bsphali. Moreover, the prepared compounds are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus

Synthetic bioactive novel ether based Schiff bases and their copper(II) complexes

NASA Astrophysics Data System (ADS)

Shabbir, Muhammad; Akhter, Zareen; Ismail, Hammad; Mirza, Bushra

2017-10-01

Novel ether based Schiff bases (HL1- HL4) were synthesized from 5-chloro-2-hydroxy benzaldehyde and primary amines (1-amino-4-phenoxybenzene, 4-(4-aminophenyloxy) biphenyl, 1-(4-aminophenoxy) naphthalene and 2-(4-aminophenoxy) naphthalene). From these Schiff bases copper(II) complexes (Cu(L1)2-Cu(L4)2)) were synthesized and characterized by elemental analysis and spectroscopic (FTIR, NMR) techniques. The synthesized Schiff bases and copper(II) complexes were further assessed for various biological studies. In brine shrimp assay the copper(II) complexes revealed 4-fold higher activity (LD50 3.8 μg/ml) as compared with simple ligands (LD50 12.4 μg/ml). Similar findings were observed in potato disc antitumor assay with higher activities for copper(II) complexes (IC50 range 20.4-24.1 μg/ml) than ligands (IC50 range 40.5-48.3 μg/ml). DPPH assay was performed to determine the antioxidant potential of the compounds. Significant antioxidant activity was shown by the copper(II) complexes whereas simple ligands have shown no activity. In DNA protection assay significant protection behavior was exhibited by simple ligand molecules while copper(II) complexes showed neutral behavior (neither protective nor damaging).

Studies on free radical scavenging, cancer cell antiproliferation, and calf thymus DNA interaction of Schiff bases.

PubMed

da Silva, Cleiton M; Silva, Marina M; Reis, Fabiano S; Ruiz, Ana Lúcia T G; de Carvalho, João E; Santos, Josué C C; Figueiredo, Isis M; Alves, Rosemeire B; Modolo, Luzia V; de Fátima, Ângelo

2017-07-01

Thirty-nine Schiff bases were synthesized by performing microwave-assisted condensation of the corresponding aldehydes and aromatic amines. Their reactive nitrogen species (RNS) scavenging activity and inhibitory effects against cancer cell growth were then subsequently investigated. Additionally, the interaction between the calf thymus DNA (ctDNA) and selected Schiff bases was evaluated using fluorescence spectroscopy, and their binding parameters were determined. The yields of the various compounds ranged from moderate to excellent (43-99%) after only a 2-min reaction. The hydroxylated Schiff bases 2, 8, 15, 16, 18, 20, 29, 32, 34, and 37 were found to be potent scavengers of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals with half-maximal scavenging concentration (SC 50 ) values lower than that of the positive control, resveratrol. The presence of hydroxyl substituents on the aromatic rings also proved essential to the cytotoxicity of the compounds. The binding constants (K b ) obtained using fluorescence spectroscopy ranged from 0.37 to 3.07×10 5 Lmol -1 , and were strongly influenced by the structure and hydroxylation degree. Schiff bases 3 and 8 showed promising cytotoxic activity, with half-maximal growth inhibitory (GI 50 ) values in the same order of magnitude as those exhibited by the reference drug, doxorubicin against various cell lines. Interestingly, these compounds also showed the highest K b , suggesting that the cytotoxic activity could be related to their interaction with the DNA of the tumor cells. The results of this study highlighted some Schiff bases as potential lead compounds for the design of new free radical scavengers and anticancer agents. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis of new 1,2,4-triazole compounds containing Schiff and Mannich bases (morpholine) with antioxidant and antimicrobial activities.

PubMed

Ünver, Yasemin; Deniz, Sadik; Çelik, Fatih; Akar, Zeynep; Küçük, Murat; Sancak, Kemal

2016-01-01

Compound 2 was synthesized by reacting CS 2 /KOH with compound 1. The treatment of compound 2 with hydrazine hydrate produced compound 3. Then, compound 3 was converted to Schiff bases (4a-d) by the handling with several aromatic aldehydes. The treatment of triazole compounds 4a-d containing Schiff base with morpholine gave compounds 5a-d. All compounds were tested for their antioxidant and antimicrobial activities. The antioxidant test results of DPPH• radical scavenging and ferric reducing/antioxidant power methods showed good antioxidant activity. The triazole-thiol (3) was the most active, and the effect of the substituent type of the thiophene ring on the activity was same for both Schiff bases (4a-d) and Mannich bases (5a-d). Among the newly synthesized triazole derivatives, the Schiff base 4d and the Mannich base 5d carrying nitro substituent on the thiophene ring showed promising antibacterial and antifungal activity, with lower MIC values than the standard antibacterial ampicillin.

Sum Rule for a Schiff-Like Dipole Moment

NASA Astrophysics Data System (ADS)

Raduta, A. A.; Budaca, R.

The energy-weighted sum rule for an electric dipole transition operator of a Schiff type differs from the Thomas-Reiche-Kuhn (TRK) sum rule by several corrective terms which depend on the number of system components, N. For illustration the formalism was applied to the case of Na clusters. One concludes that the random phase approximation (RPA) results for Na clusters obey the modified TRK sum rule.

Return on investment of advanced practice medical degrees: NPs vs. PAs.

PubMed

Craig, Christopher K; Holmes, James H; Carter, Jeffery E

2017-06-01

As the United States faces a predicted physician shortage over the next 2 decades, physician assistants (PAs) and NPs are expected to fill the void. At the same time, because education is expensive, student loan and tuition increases have many potential applicants assessing differences in reimbursement and wondering about their return on investment (ROI). An analysis compared PA and NP salaries by incorporating national salary data, federal income tax, and student loans for a comparative analysis of each career pathway. Salaries were abstracted from the 2012 Bureau of Labor Statistics database. The net present value (NPV) of PA and NP salaries was calculated with a 5% discount rate. Principal and interest for student loans was calculated at a 6% interest fixed-rate loan over 30 years. NPVs were then compared with projected ROI at retirement age. Relative career values were also given to each career choice, based on a retirement age of 65 years, which translates to about 41 years of employment for both PAs and NPs. PAs' and NPs' educational loans both equalled $129,484 on total repayment. The median annual salary of a PA was $90,930 and $89,960 for an NP. PA data yielded a 5% NPV of $781,323 compared with $764,348 for NPs. Of note, the 5% NPV of a 4-year nursing degree is $728,436. PAs have a slightly higher ROI compared with NPs. These findings may change due to adjustments in nursing training models. Many PA programs allow matriculation immediately after obtaining a bachelor's degree. NP schools often require nursing experience before entering their program. Some schools are considering an accelerated NP program, allowing immediate matriculation after obtaining a bachelor's degree. Because many NP programs have become doctoral degrees, the increased duration of training, higher tuition, and fewer years worked before retirement lower the overall NP ROI. A similar reduction in ROI was considered marginal in PAs who attend residency programs-though these programs are

Developing Tools to Search for PNe in the J­PAS Survey

NASA Astrophysics Data System (ADS)

Gonçalves, D.; Villegas, T. A.; Marcolino, W.; Lorenz-Martins, S.; Borges Fernandes, M.; Kanaan, A.; Pereira, C. B.; Daflon, S.; Ederoclite, A.; Alfaro, E. J.; Ribeiro, T.; Vázquez Ramió, H.; Schmitz, T.; Martínez-Delgado, D.; JPAS Collaboration

2014-04-01

The Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a new astronomical facility dedicated to mapping the observable Universe in 59 colors, and will produce high-quality images and an unique spectral resolution over the 8000 deg^2. It will consist of two telescopes. One of 2.5-m (J-PAS) and another of 0.8-m (J-PLUS, mainly for calibrations). The former will have a dedicated 1.2-G pixel survey camera (containing an array of 14 CCDs) with a FoV of 5 deg^2. It is planned to take 4-5 years and is expected to map the above area to a 5σ magnitude depth for point sources equivalent to i˜23.3 over an aperture of 2 arcsec^2. The J-PAS filter system consists of 54 contiguous narrow band filters of 100-Å FWHM, from 3,500 to 10,000Å. To those filters 2 broad-band ones will be at the extremes, UV and IR, plus 3 SDSS g, r, and i filters. J-PLUS, on the other hand, comprise 12 filters, including g, r, i and z SDSS ones. Though about 2,500 PNe (confirmed spectroscopically) are known in the Galaxy, only about 20 objects have been identified as halo PNe. They were found from their location, kinematics and chemistry. Halo PNe are able to reveal precious information for the study of low- and intermediate-mass star evolution and the early chemical conditions of the Galaxy. The characteristic low continuum and intense line emissions of PNe make them good objects to be searched for by J-PAS. For instance, the halo PNe BoBn 1, DdDm 1 and PS 1, located somewhere between 11 and 24 kpc from the Sun, have B magnitudes of 16, 14 and 13.4, respectively. Such values are easily encompassed by J-PAS, given the typical limit magnitude of the survey. Because of the low number of halo PNe detected so far, we are developing tools to find these objects by using J-PAS/J-PLUS, and planning a follow-up study for any possible candidate identified by the survey. Color magnitudes diagram able to separate PNe from other strong line emission objects are being explored by the

Composition, Characterization and Antibacterial activity of Mn(II), Co(II),Ni(II), Cu(II) Zn(II) and Cd(II) mixed ligand complexes Schiff base derived from Trimethoprim with 8-Hydroxy quinoline

NASA Astrophysics Data System (ADS)

Numan, Ahmed T.; Atiyah, Eman M.; Al-Shemary, Rehab K.; Ulrazzaq, Sahira S. Abd

2018-05-01

New Schiff base ligand 2-((4-amino-5-(3, 4, 5-trimethoxybenzyl) pyrimidin-2-ylimino) (phenyl)methyl)benzoic acid] = [HL] was synthesized using microwave irradiation trimethoprim and 2-benzoyl benzoic acid. Mixed ligand complexes of Mn((II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) are reacted in ethanol with Schiff base ligand [HL] and 8-hydroxyquinoline [HQ] then reacted with metal salts in ethanol as a solvent in (1:1:1) ratio. The ligand [HL] is characterized by FTIR, UV-Vis, melting point, elemental microanalysis (C.H.N), 1H-NMR, 13C-NMR, and mass spectra. The mixed ligand complexes are characterized by infrared spectra, electronic spectra, (C.H.N), melting point, atomic absorption, molar conductance and magnetic moment measurements. These measurements indicate that the ligand [HL] coordinates with metal (II) ion in a tridentate manner through the oxygen and nitrogen atoms of the ligand, octahedral structures are suggested for these complexes. Antibacterial activity of the ligands [HL], [HQ] and their complexes are studied against (gram positive) and (gram negative) bacteria.

Dual Fatty Acid Elongase Complex Interactions in Arabidopsis

PubMed Central

Morineau, Céline; Gissot, Lionel; Bellec, Yannick; Hematy, Kian; Tellier, Frédérique; Renne, Charlotte; Haslam, Richard; Beaudoin, Frédéric; Napier, Johnathan; Faure, Jean-Denis

2016-01-01

Very long chain fatty acids (VLCFAs) are involved in plant development and particularly in several cellular processes such as membrane trafficking, cell division and cell differentiation. However, the precise role of VLCFAs in these different cellular processes is still poorly understood in plants. In order to identify new factors associated with the biosynthesis or function of VLCFAs, a yeast multicopy suppressor screen was carried out in a yeast mutant strain defective for fatty acid elongation. Loss of function of the elongase 3 hydroxyacyl-CoA dehydratase PHS1 in yeast and PASTICCINO2 in plants prevents growth and induces cytokinesis defects. PROTEIN TYROSIN PHOSPHATASE-LIKE (PTPLA) previously characterized as an inactive dehydratase was able to restore yeast phs1 growth and VLCFAs elongation but not the plant pas2-1 defects. PTPLA interacted with elongase subunits in the Endoplasmic Reticulum (ER) and its absence induced the accumulation of 3-hydroxyacyl-CoA as expected from a dehydratase involved in fatty acid (FA) elongation. However, loss of PTPLA function increased VLCFA levels, an effect that was dependent on the presence of PAS2 indicating that PTPLA activity repressed FA elongation. The two dehydratases have specific expression profiles in the root with PAS2, mostly restricted to the endodermis, while PTPLA was confined in the vascular tissue and pericycle cells. Comparative ectopic expression of PTPLA and PAS2 in their respective domains confirmed the existence of two independent elongase complexes based on PAS2 or PTPLA dehydratase that are functionally interacting. PMID:27583779

Dual Fatty Acid Elongase Complex Interactions in Arabidopsis.

PubMed

Morineau, Céline; Gissot, Lionel; Bellec, Yannick; Hematy, Kian; Tellier, Frédérique; Renne, Charlotte; Haslam, Richard; Beaudoin, Frédéric; Napier, Johnathan; Faure, Jean-Denis

2016-01-01

Very long chain fatty acids (VLCFAs) are involved in plant development and particularly in several cellular processes such as membrane trafficking, cell division and cell differentiation. However, the precise role of VLCFAs in these different cellular processes is still poorly understood in plants. In order to identify new factors associated with the biosynthesis or function of VLCFAs, a yeast multicopy suppressor screen was carried out in a yeast mutant strain defective for fatty acid elongation. Loss of function of the elongase 3 hydroxyacyl-CoA dehydratase PHS1 in yeast and PASTICCINO2 in plants prevents growth and induces cytokinesis defects. PROTEIN TYROSIN PHOSPHATASE-LIKE (PTPLA) previously characterized as an inactive dehydratase was able to restore yeast phs1 growth and VLCFAs elongation but not the plant pas2-1 defects. PTPLA interacted with elongase subunits in the Endoplasmic Reticulum (ER) and its absence induced the accumulation of 3-hydroxyacyl-CoA as expected from a dehydratase involved in fatty acid (FA) elongation. However, loss of PTPLA function increased VLCFA levels, an effect that was dependent on the presence of PAS2 indicating that PTPLA activity repressed FA elongation. The two dehydratases have specific expression profiles in the root with PAS2, mostly restricted to the endodermis, while PTPLA was confined in the vascular tissue and pericycle cells. Comparative ectopic expression of PTPLA and PAS2 in their respective domains confirmed the existence of two independent elongase complexes based on PAS2 or PTPLA dehydratase that are functionally interacting.

Artificial ligand binding within the HIF2[alpha] PAS-B domain of the HIF2 transcription factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scheuermann, Thomas H.; Tomchick, Diana R.; Machius, Mischa

2009-05-12

The hypoxia-inducible factor (HIF) basic helix-loop-helix Per-aryl hydrocarbon receptor nuclear translocator (ARNT)-Sim (bHLH-PAS) transcription factors are master regulators of the conserved molecular mechanism by which metazoans sense and respond to reductions in local oxygen concentrations. In humans, HIF is critically important for the sustained growth and metastasis of solid tumors. Here, we describe crystal structures of the heterodimer formed by the C-terminal PAS domains from the HIF2{alpha} and ARNT subunits of the HIF2 transcription factor, both in the absence and presence of an artificial ligand. Unexpectedly, the HIF2{alpha} PAS-B domain contains a large internal cavity that accommodates ligands identified frommore » a small-molecule screen. Binding one of these ligands to HIF2{alpha} PAS-B modulates the affinity of the HIF2{alpha}:ARNT PAS-B heterodimer in vitro. Given the essential role of PAS domains in forming active HIF heterodimers, these results suggest a presently uncharacterized ligand-mediated mechanism for regulating HIF2 activity in endogenous and clinical settings.« less

Synthesis, crystal structures, molecular docking and urease inhibition studies of Ni(II) and Cu(II) Schiff base complexes

NASA Astrophysics Data System (ADS)

Sangeeta, S.; Ahmad, K.; Noorussabah, N.; Bharti, S.; Mishra, M. K.; Sharma, S. R.; Choudhary, M.

2018-03-01

[Ni(L)2] 1 and [Cu(L)2] 2 [HL = 2-((E)-(2-methoxyphenylimino)methyl)-4,6-dichlorophenol] Schiff base complexes have been successfully synthesized and were characterized by FT-IR, UV-Vis, fluorescence spectroscopy and thermogravimetric analysis. The crystal structures of the two complexes were determined through X-ray crystallography. Its inhibitory activity against Helicobacter pylori urease was evaluated in vitro and showed strong inhibitory activity against H. pylori urease compared with acetohydroxamic acid (IC50 = 42.12 μmolL-1), which is a positive reference. A docking analysis using the AutoDock 4.0 program could explain the inhibitory activity of the complex against urease.

Silica functionalized Cu(II) acetylacetonate Schiff base complex: An efficient catalyst for the oxidative condensation reaction of benzyl alcohol with amines

NASA Astrophysics Data System (ADS)

Anbarasu, G.; Malathy, M.; Karthikeyan, P.; Rajavel, R.

2017-09-01

Silica functionalized Cu(II) acetylacetonate Schiff base complex via the one pot reaction of silica functionalized 3-aminopropyltriethoxysilane with acetyl acetone and copper acetate has been reported. The synthesized material was well characterized by analytical techniques such as FT-IR, UV-DRS, XRD, SEM-EDX, HR-TEM, EPR, ICP-AES and BET analysis. The characterization results confirmed the grafting of Cu(II) Schiff base complex on the silica surface. The catalytic activity of synthesized silica functionalized Cu(II) acetylacetonate Schiff base complex was evaluated through the oxidative condensation reaction of benzyl alcohol to imine.

Synthesis and Characterization of Metal Complexes with Schiff Base Ligands

ERIC Educational Resources Information Center

Wilkinson, Shane M.; Sheedy, Timothy M.; New, Elizabeth J.

2016-01-01

In order for undergraduate laboratory experiments to reflect modern research practice, it is essential that they include a range of elements, and that synthetic tasks are accompanied by characterization and analysis. This intermediate general chemistry laboratory exercise runs over 2 weeks, and involves the preparation of a Schiff base ligand and…

A new chitosan Schiff base supported Pd(II) complex for microwave-assisted synthesis of biaryls compounds

NASA Astrophysics Data System (ADS)

Baran, Talat

2017-08-01

In this study, a new heterogeneous palladium (II) catalyst that contains O-carboxymethyl chitosan Schiff base has been designed for Suzuki coupling reactions. The chemical structures of the synthesized catalyst were characterized with the FTIR, TG/DTG, ICP-OES, SEM/EDAX, 1H NMR, 13C NMR, GC/MS, XRD, and magnetic moment techniques. The reusability and catalytic behavior of heterogeneous catalyst was tested towards Suzuki reactions. As a result of the tests, excellent selectivity was obtained, and by-products of homo coupling were not seen in the spectra. The biaryls products were identified on a GC/MS. In addition, it was determined in the reusability tests that the catalysts could be used several times (seven runs). More importantly, with very low catalyst loading (6 × 10-3 mol %) in very short reaction time (5 min), chitosan Schiff base supported Pd(II) complex gave high TON and TOF values. These findings showed that Schiff base supported Pd(II) catalyst is suitable for Suzuki cross coupling reactions.

Substitution of amino acids Asp-85, Asp-212, and Arg-82 in bacteriorhodopsin affects the proton release phase of the pump and the pK of the Schiff base.

PubMed

Otto, H; Marti, T; Holz, M; Mogi, T; Stern, L J; Engel, F; Khorana, H G; Heyn, M P

1990-02-01

Photocycle and flash-induced proton release and uptake were investigated for bacteriorhodopsin mutants in which Asp-85 was replaced by Ala, Asn, or Glu; Asp-212 was replaced by Asn or Glu; Asp-115 was replaced by Ala, Asn, or Glu; Asp-96 was replaced by Ala, Asn, or Glu; and Arg-82 was replaced by Ala or Gln in dimyristoylphosphatidylcholine/3-[(3-cholamidopropyl)dimethylammonio]-1- propanesulfonate micelles at pH 7.3. In the Asp-85----Ala and Asp-85----Asn mutants, the absence of the charged carboxyl group leads to a blue chromophore at 600 and 595 nm, respectively, and lowers the pK of the Schiff base deprotonation to 8.2 and 7, respectively, suggesting a role for Asp-85 as counterion to the Schiff base. The early part of the photocycles of the Asp-85----Ala and Asp-85----Asn mutants is strongly perturbed; the formation of a weak M-like intermediate is slowed down about 100-fold over wild type. In both mutants, proton release is also slower but clearly precedes the rise of M. The amplitude of the early (less than 0.2 microseconds) reversed photovoltage component in the Asp-85----Asn mutant is very large, and the net charge displacement is close to zero, indicating proton release and uptake on the cytoplasmic side of the membrane. The data suggest an obligatory role for Asp-85 in the efficient deprotonation of the Schiff base and in the proton release phase, probably as proton acceptor. In the Asp-212----Asn mutant, the rise of the absorbance change at 410 nm is slowed down to 220 microsecond, its amplitude is small, and the release of protons is delayed to 1.9 ms. The absorbance changes at 650 nm indicate perturbations in the early time range with a slow K intermediate. Thus Asp-212 also participates in the early events of charge translocation and deprotonation of the Schiff base. In the Arg-82----Gln mutant, no net transient proton release was observed, whereas, in the Arg-82----Ala mutant, uptake and release were reversed. The pK shift of the purple

Efficient Synthesis and Discovery of Schiff Bases as Potent Cholinesterase Inhibitors.

PubMed

Razik, Basma M Abd; Osman, Hasnah; Ezzat, Mohammed O; Basiri, Alireza; Salhin, Abdussalam; Kia, Yalda; Murugaiyah, Vikneswaran

2016-01-01

The search for new cholinesterase inhibitors is still a promising approach for management of Alzheimer`s disease. Schiff bases are considered as important class of organic compounds, which have wide range of applications including as enzyme inhibitors. In the present study, a new green ionic liquid mediated strategy was developed for convenient synthesis of two series of Schiff bases 3(a-j) and 5(a-j) as potential cholinesterase inhibitors using aromatic aldehydes and primary amines in [bmim]Br. The synthesized compounds were evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential by modified Ellman's method. The molecular interactions between the most active compound and the enzyme were analyzed by molecular docking. Among them, 3j displayed higher inhibitory activities than reference drug, galanthamine, with IC50 values of 2.05 and 5.77 µM, for AChE and BChE, respectively. Interestingly, all the compounds except 3b displayed higher BChE inhibitions than galanthamine with IC50 values ranging from 5.77 to 18.52 µM. Molecular docking of compound 3j inside the TcAChE and hBChE completely coincided with the inhibitory activities observed. The compound forms strong hydrogen bonding at the peripheral anionic site of AChE whereas on BChE, it had hydrophobic and mild polar interactions. An efficient and eco-friendly synthetic methodology has been developed to synthesize Schiff bases in a very short reaction time and excellent yields in ionic solvent, whereby the compounds from series 3 showed promising cholinesterase inhibitory activity.

Sodium p-Aminosalicylic Acid Reverses Sub-Chronic Manganese-Induced Impairments of Spatial Learning and Memory Abilities in Rats, but Fails to Restore γ-Aminobutyric Acid Levels.

PubMed

Li, Shao-Jun; Ou, Chao-Yan; He, Sheng-Nan; Huang, Xiao-Wei; Luo, Hai-Lan; Meng, Hao-Yang; Lu, Guo-Dong; Jiang, Yue-Ming; Vieira Peres, Tanara; Luo, Yi-Ni; Deng, Xiang-Fa

2017-04-10

Excessive manganese (Mn) exposure is not only a health risk for occupational workers, but also for the general population. Sodium para-aminosalicylic acid (PAS-Na) has been successfully used in the treatment of manganism, but the involved molecular mechanisms have yet to be determined. The present study aimed to investigate the effects of PAS-Na on sub-chronic Mn exposure-induced impairments of spatial learning and memory, and determine the possible involvements of γ-aminobutyric acid (GABA) metabolism in vivo. Sprague-Dawley male rats received daily intraperitoneal injections MnCl₂ (as 6.55 mg/kg Mn body weight, five days per week for 12 weeks), followed by daily subcutaneous injections of 100, 200, or 300 mg/kg PAS-Na for an additional six weeks. Mn exposure significantly impaired spatial learning and memory ability, as noted in the Morris water maze test, and the following PAS-Na treatment successfully restored these adverse effects to levels indistinguishable from controls. Unexpectedly, PAS-Na failed to recover the Mn-induced decrease in the overall GABA levels, although PAS-Na treatment reversed Mn-induced alterations in the enzyme activities directly responsible for the synthesis and degradation of GABA (glutamate decarboxylase and GABA-transaminase, respectively). Moreover, Mn exposure caused an increase of GABA transporter 1 (GAT-1) and decrease of GABA A receptor (GABA A ) in transcriptional levels, which could be reverted by the highest dose of 300 mg/kg PAS-Na treatment. In conclusion, the GABA metabolism was interrupted by sub-chronic Mn exposure. However, the PAS-Na treatment mediated protection from sub-chronic Mn exposure-induced neurotoxicity, which may not be dependent on the GABA metabolism.

Sodium p-Aminosalicylic Acid Reverses Sub-Chronic Manganese-Induced Impairments of Spatial Learning and Memory Abilities in Rats, but Fails to Restore γ-Aminobutyric Acid Levels

PubMed Central

Li, Shao-Jun; Ou, Chao-Yan; He, Sheng-Nan; Huang, Xiao-Wei; Luo, Hai-Lan; Meng, Hao-Yang; Lu, Guo-Dong; Jiang, Yue-Ming; Vieira Peres, Tanara; Luo, Yi-Ni; Deng, Xiang-Fa

2017-01-01

Excessive manganese (Mn) exposure is not only a health risk for occupational workers, but also for the general population. Sodium para-aminosalicylic acid (PAS-Na) has been successfully used in the treatment of manganism, but the involved molecular mechanisms have yet to be determined. The present study aimed to investigate the effects of PAS-Na on sub-chronic Mn exposure-induced impairments of spatial learning and memory, and determine the possible involvements of γ-aminobutyric acid (GABA) metabolism in vivo. Sprague-Dawley male rats received daily intraperitoneal injections MnCl2 (as 6.55 mg/kg Mn body weight, five days per week for 12 weeks), followed by daily subcutaneous injections of 100, 200, or 300 mg/kg PAS-Na for an additional six weeks. Mn exposure significantly impaired spatial learning and memory ability, as noted in the Morris water maze test, and the following PAS-Na treatment successfully restored these adverse effects to levels indistinguishable from controls. Unexpectedly, PAS-Na failed to recover the Mn-induced decrease in the overall GABA levels, although PAS-Na treatment reversed Mn-induced alterations in the enzyme activities directly responsible for the synthesis and degradation of GABA (glutamate decarboxylase and GABA-transaminase, respectively). Moreover, Mn exposure caused an increase of GABA transporter 1 (GAT-1) and decrease of GABA A receptor (GABAA) in transcriptional levels, which could be reverted by the highest dose of 300 mg/kg PAS-Na treatment. In conclusion, the GABA metabolism was interrupted by sub-chronic Mn exposure. However, the PAS-Na treatment mediated protection from sub-chronic Mn exposure-induced neurotoxicity, which may not be dependent on the GABA metabolism. PMID:28394286

Cache domains that are homologous to, but different from PAS domains comprise the largest superfamily of extracellular sensors in prokaryotes

DOE PAGES

Upadhyay, Amit A.; Fleetwood, Aaron D.; Adebali, Ogun; ...

2016-04-06

Cellular receptors usually contain a designated sensory domain that recognizes the signal. Per/Arnt/Sim (PAS) domains are ubiquitous sensors in thousands of species ranging from bacteria to humans. Although PAS domains were described as intracellular sensors, recent structural studies revealed PAS-like domains in extracytoplasmic regions in several transmembrane receptors. However, these structurally defined extracellular PAS-like domains do not match sequence-derived PAS domain models, and thus their distribution across the genomic landscape remains largely unknown. Here we show that structurally defined extracellular PAS-like domains belong to the Cache superfamily, which is homologous to, but distinct from the PAS superfamily. Our newly builtmore » computational models enabled identification of Cache domains in tens of thousands of signal transduction proteins including those from important pathogens and model organisms.Moreover, we show that Cache domains comprise the dominant mode of extracellular sensing in prokaryotes.« less

Cache domains that are homologous to, but different from PAS domains comprise the largest superfamily of extracellular sensors in prokaryotes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Upadhyay, Amit A.; Fleetwood, Aaron D.; Adebali, Ogun

Cellular receptors usually contain a designated sensory domain that recognizes the signal. Per/Arnt/Sim (PAS) domains are ubiquitous sensors in thousands of species ranging from bacteria to humans. Although PAS domains were described as intracellular sensors, recent structural studies revealed PAS-like domains in extracytoplasmic regions in several transmembrane receptors. However, these structurally defined extracellular PAS-like domains do not match sequence-derived PAS domain models, and thus their distribution across the genomic landscape remains largely unknown. Here we show that structurally defined extracellular PAS-like domains belong to the Cache superfamily, which is homologous to, but distinct from the PAS superfamily. Our newly builtmore » computational models enabled identification of Cache domains in tens of thousands of signal transduction proteins including those from important pathogens and model organisms.Moreover, we show that Cache domains comprise the dominant mode of extracellular sensing in prokaryotes.« less

47 CFR Appendix B to Part 64 - Priority Access Service (PAS) for National Security and Emergency Preparedness (NSEP)

Code of Federal Regulations, 2013 CFR

2013-10-01

... providers as necessary to maintain the viability of the PAS system. 5. Maintain a database for PAS related... NSEP PAS database only to those having a need-to-know or who will not use the information for economic... selected for this priority should be responsible for ensuring the viability or reconstruction of the basic...

47 CFR Appendix B to Part 64 - Priority Access Service (PAS) for National Security and Emergency Preparedness (NSEP)

Code of Federal Regulations, 2011 CFR

2011-10-01

... providers as necessary to maintain the viability of the PAS system. 5. Maintain a database for PAS related... NSEP PAS database only to those having a need-to-know or who will not use the information for economic... selected for this priority should be responsible for ensuring the viability or reconstruction of the basic...

47 CFR Appendix B to Part 64 - Priority Access Service (PAS) for National Security and Emergency Preparedness (NSEP)

Code of Federal Regulations, 2014 CFR

2014-10-01

... providers as necessary to maintain the viability of the PAS system. 5. Maintain a database for PAS related... NSEP PAS database only to those having a need-to-know or who will not use the information for economic... selected for this priority should be responsible for ensuring the viability or reconstruction of the basic...

47 CFR Appendix B to Part 64 - Priority Access Service (PAS) for National Security and Emergency Preparedness (NSEP)

Code of Federal Regulations, 2012 CFR

2012-10-01

... providers as necessary to maintain the viability of the PAS system. 5. Maintain a database for PAS related... NSEP PAS database only to those having a need-to-know or who will not use the information for economic... selected for this priority should be responsible for ensuring the viability or reconstruction of the basic...

Mycobacterium tuberculosis Arylamine N-Acetyltransferase Acetylates and Thus Inactivates para-Aminosalicylic Acid.

PubMed

Wang, Xude; Yang, Shanshan; Gu, Jing; Deng, Jiaoyu

2016-12-01

Mycobacterium tuberculosis arylamine N-acetyltransferase (TBNAT) is able to acetylate para-aminosalicylic acid (PAS) both in vitro and in vivo as determined by high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS) techniques. The antituberculosis activity of the acetylated PAS is significantly reduced. As a result, overexpression of TBNAT in M. tuberculosis results in PAS resistance, as determined by MIC tests and drug exposure experiments. Taken together, our results suggest that TBNAT from M. tuberculosis is able to inactivate PAS by acetylating the compound. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Synthesis and Degradation of Schiff Bases Containing Heterocyclic Pharmacophore

PubMed Central

Ledeţi, Ionuţ; Alexa, Anda; Bercean, Vasile; Vlase, Gabriela; Vlase, Titus; Şuta, Lenuţa-Maria; Fuliaş, Adriana

2015-01-01

This paper reports on the synthesis and characterization of two Schiff bases bearing 1,2,4-triazolic moieties, namely 4H-4-(2-hydroxy-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole and 4H-4-(4-nitro-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole using thin layer chromatography, melting interval, elemental analysis, spectroscopy and thermal stability studies. PMID:25590299

Synthesis, spectroscopic, coordination and biological activities of some organometallic complexes derived from thio-Schiff base ligands

NASA Astrophysics Data System (ADS)

Abou-Hussein, Azza A.; Linert, Wolfgang

2014-01-01

Two series of mono- and binuclear complexes cyclic or acyclic thio-ferocine Schiff base ligands, derived from the condensation of 2-aminobenzenthiol (L) with monoacetyl ferrocene in the molar ratio 1:1 or in the molar ratio 1:2 for diacetyl ferocine have been prepared. The condensation reactions yield the corresponding Schiff Base ligands, HLa-Maf and H2Lb-Daf. The chelation of the ligands to metal ions occurs through the sulfur of the thiol group as well as the nitrogen atoms of the azomethine group of the ligands. HLa-Maf acts as monobasic bidentate or dibasic tetradentate, while H2Lb-Daf behaves as twice negatively cargend tetradentate ligand. The structures of these ligands were elucidated by elemental analysis, infrared, ultraviolet-visible spectra, as well as 1H NMR spectra. Reactions of the Schiff bases ligands with ruthenium(III), oxovanadium(IV) and dioxouranium(VI) afforded the corresponding transition metal complexes. The properties of the newly prepared complexes were analyse by elemental analyses, infrared, electronic spectra, 1H NMR as well as the magnetic susceptibility and conductivity measurement. The metal complexes exhibits different geometrical arrangements such as octahedral and square pyramidal coordination. Schiff base ligands and their metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi to study their biological activity. All the complexes exhibit antibacterial and antifungal activities against these organisms.

Pituitary Adenoma With Paraganglioma/Pheochromocytoma (3PAs) and Succinate Dehydrogenase Defects in Humans and Mice

PubMed Central

Xekouki, Paraskevi; Szarek, Eva; Bullova, Petra; Giubellino, Alessio; Quezado, Martha; Mastroyannis, Spyridon A.; Mastorakos, Panagiotis; Wassif, Christopher A.; Raygada, Margarita; Rentia, Nadia; Dye, Louis; Cougnoux, Antony; Koziol, Deloris; Sierra, Maria de La Luz; Lyssikatos, Charalampos; Belyavskaya, Elena; Malchoff, Carl; Moline, Jessica; Eng, Charis; Maher, Louis James; Pacak, Karel; Lodish, Maya

2015-01-01

Context: Germline mutations in genes coding succinate dehydrogenase (SDH) subunits A, B, C, and D have been identified in familial paragangliomas (PGLs)/pheochromocytomas (PHEOs) and other tumors. We described a GH-secreting pituitary adenoma (PA) caused by SDHD mutation in a patient with familial PGLs. Additional patients with PAs and SDHx defects have since been reported. Design: We studied 168 patients with unselected sporadic PA and with the association of PAs, PGLs, and/or pheochromocytomas, a condition we named the 3P association (3PAs) for SDHx germline mutations. We also studied the pituitary gland and hormonal profile of Sdhb+/− mice and their wild-type littermates at different ages. Results: No SDHx mutations were detected among sporadic PA, whereas three of four familial cases were positive for a mutation (75%). Most of the SDHx-deficient PAs were either prolactinomas or somatotropinomas. Pituitaries of Sdhb+/− mice older than 12 months had an increased number mainly of prolactin-secreting cells and several ultrastructural abnormalities such as intranuclear inclusions, altered chromatin nuclear pattern, and abnormal mitochondria. Igf-1 levels of mutant mice tended to be higher across age groups, whereas Prl and Gh levels varied according to age and sex. Conclusion: The present study confirms the existence of a new association that we termed 3PAs. It is due mostly to germline SDHx defects, although sporadic cases of 3PAs without SDHx defects also exist. Using Sdhb+/− mice, we provide evidence that pituitary hyperplasia in SDHx-deficient cells may be the initial abnormality in the cascade of events leading to PA formation. PMID:25695889

Graphene oxide for solid-phase extraction of bioactive phenolic acids.

PubMed

Hou, Xiudan; Wang, Xusheng; Sun, Yingxin; Wang, Licheng; Guo, Yong

2017-05-01

A solid-phase extraction (SPE) method for the efficient analysis of trace phenolic acids (PAs, caffeic acid, ferulic acid, protocatechuic acid, cinnamic acid) in urine was established. In this work, a graphene oxide (GO) coating was grafted onto pure silica to be investigated as SPE material. The prepared GO surface had a layered and wrinkled structure that was rough and well organized, which could provide more open adsorption sites. Owing to its hydrophilicity and polarity, GO showed higher extraction efficiency toward PAs than reduced GO did, in agreement with the theoretical calculation results performed by Gaussian 09 software. The adsorption mechanism of PAs on GO@Sil was also investigated through static state and kinetic state adsorption experiments, which showed a monolayer surface adsorption. Extraction capacity of the as-prepared material was optimized using the response surface methodology. Under the optimized conditions, the as-established method provided wide linearity range (2-50 μg L -1 for protocatechuic acid and 1-50 μg L -1 for caffeic acid, ferulic acid, and cinnamic acid) and low limits of detection (0.25-1 μg L -1 ). Finally, the established method was applied for the analysis of urine from two healthy volunteers. The results indicate that the prepared material is a practical, cost-effective medium for the extraction and determination of phenolic acids in complex matrices. Graphical Abstract A graphene oxide coating was grafted onto pure silica as the SPE material for the extraction of phenolic acids in urines and the extraction mechanism was also mainly investigated.

Optical Sensing Properties of Pyrene-Schiff Bases toward Different Acids.

PubMed

Babgi, Bandar A; Alzahrani, Asma

2016-07-01

A set of (4-substituted-phenyl)-pyren-1-ylmethylene-amine (PMA) was prepared by the reaction of pyrene-1-carboxaldehyde and the corresponding 4-substituted aniline. The structure of the PMA compounds were confirmed by spectroscopic data (IR, (1)HNMR, (13)CNMR, ISI-MS and elemental analysis. The structure of (4-bromo-phenyl)-pyren-1-ylmethylene-amine (BrPMA) was further confirmed by the single X-ray crystallography. The absorption and emission spectroscopic behaviors were investigated in variant acids. The compounds showed dramatic spectroscopic changes upon acidifying with strong acids and negligible effects when weak acids are used in the acidifications. Hence, the PMA compounds can be used as sensors to distinguish between weak and strong acids.

Synthesis, crystal structure and biological activity of the Schiff base organotin(IV) complexes based on salicylaldehyde-o-aminophenol

NASA Astrophysics Data System (ADS)

Tan, Yu-Xing; Zhang, Zhi-Jian; Liu, Yang; Yu, Jiang-Xi; Zhu, Xiao-Ming; Kuang, Dai-Zhi; Jiang, Wu-Jiu

2017-12-01

Schiff base organotin(IV) complexes C1 ∼ C5b have been synthesized via the reaction of the substituted salicylaldehyde-o-aminophenol Schiff base ligands (L1 ∼ L3) with the dibenzyltin dichloride, n-butyltin trichloride or dibutyltin oxide, respectively. The complexes have been characterized by IR, UV-Vis, 1H NMR, 13C NMR spectra, elemental analysis and the crystal structures have been determined by X-ray diffraction. The anticancer activity of the Schiff base ligand and complexes C1 ∼ C5b against five species of cancer cell which are Hela, MCF7, HepG2, Colo205, NCIsbnd H460 were tested respectively, the tests showed that C1 ∼ C5b exhibited significant anticancer activity for the cancer cells in comparison with the ligand, and the activity was greater than carboplatin.

Synthesis of phosphonic acid silver-graphene oxide nanomaterials with photocatalytic activity through ultrasonic-assisted method.

PubMed

Li, Yongshen; Song, Yunna; Ma, Zheng; Niu, Shuai; Li, Jihui; Li, Ning

2018-06-01

In this article, phosphonic acid silver-graphene oxide nanomaterials (Nano-PAS-GO) was synthesized from silver nitrate (AgNO 3 ) solution and phosphoric graphene oxide (PGO) via the convenient ultrasonic-assisted method, and the structure and morphology were characterized, and the photocatalytic activity and recyclability were evaluated through photocatalyzing degradation of Rhodamin B (RhB) aqueous solution, and the possible photocatalytic mechanism was also discussed. Based on those, it was confirmed that Nano-PAS-GO has been synthesized from AgNO 3 solution and PGO colloidal suspension under ultrasonic-assisted condition, and Nano-PAS-GO has consisted of phosphoric acid silver nanoparticles and GO with 2D lattice (2D GO lattice) connected in the form of C-P bonds, and the photodegradation rate of Nano-PAS-GO for RhB aqueous solution has reached 93.99%, and Nano-PAS-GO has possessed the nicer recyclability when the photocatalytic time was 50 min. From those results, the strong and stable interface . between PAS nanoparticles and 2D GO lattice connected in the form of the covalent bonds has effectively inhibited the occurrence of the photocorrosion phenomenon. Copyright © 2018 Elsevier B.V. All rights reserved.

The Schiff angular bremsstrahlung distribution from composite media

NASA Astrophysics Data System (ADS)

Taylor, M. L.; Dalton, B.; Franich, R. D.

2012-12-01

The Schiff differential for the angular distribution of bremsstrahlung is widely employed, but calculations involving composite materials (i.e. compounds and mixtures) are often undertaken in a somewhat ad hoc fashion. In this work, we suggest an alternative approach to power-law estimates of the effective atomic number utilising Seltzer and Berger's combined approach in order to generate single-valued effective atomic numbers applicable over a large energy range (in the worst case deviation from constancy of about 2% between 10 keV and 1 GeV). Differences with power-law estimates of Z for composites are potentially significant, particularly for low-Z media such as biological or surrogate materials as relevant within the context of medical physics. As an example, soft tissue differs by >70% and cortical bone differs by >85%, while for high-Z composites such as a tungsten-rhenium alloy the difference is of the order of 1%. Use of the normalised Schiff formula for shape only does not exhibit strong Z dependence. Consequently, in such contexts the differences are negligible - the power-law approach overestimates the magnitude by 1.05% in the case of water and underestimates it by <0.1% for the high-Z alloys. The differences in the distribution are most pronounced for small angles and where the bremsstrahlung quanta are low energy.

Searching for planetary nebulae at the Galactic halo via J-PAS and J-PLUS

NASA Astrophysics Data System (ADS)

Goncalves, Denise R.; Aparício-Villegas, Teresa; Akras, Stavros; Borges Fernandes, Marcelo; J-PAS Collaboration

2015-08-01

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a narrow-band imaging, very wide field cosmological survey to be carried out from a dedicated 2.5m telescope and a 4.7 sq.deg camera with 1.2Gpix. It will last 5 years and will observe 8500 sq.deg of Northern sky to a 5-σ magnitude depth for point sources, equivalent to i ~23.3 over an aperture of 2 arcsec2. The J-PAS filter system consists of 54 contiguous narrow band filters of 145-Å FWHM, from 3,500 to 10,000Å. Two broad-band filters will be added at the extremes, UV and IR, plus 3 SDSS g, r, and i filters. The Javalambre Photometric Local Universe Survye (J-PLUS) will be an auxiliary survey ofJ-PAS (mainly for calibration) with a dedicated 0.80m telescope. J-PLUS comprises 12 filters, including g, r, i and z SDSS ones. Though about 2,500 planetary nebulae (PNe, confirmed spectroscopically) are known in the Galaxy, only 14 objects have been convincingly identified as halo PNe. They were classified as such from their location, kinematics and chemistry. Halo PNe are able to reveal precious information for the study of low- and intermediate-mass star evolution and the early chemical conditions of the Galaxy. The characteristic low continuum and intense line emissions of PNe make them good objects to be searched by J-PAS, and even by J-PLUS. For instance, the halo PNe BoBn 1, DdDm 1 and PS 1, located somewhere between 11 and 24 kpc from the Sun, have B magnitudes of 16, 14 and 13.4, respectively. Such values are easily encompassed by J-PAS/J-PLUS, given the typical limit magnitude of the survey. Though covering a significantly smaller sky area, data from the ALHAMBRA survey were used to test our J-PAS/J-PLUS strategy to search for PNe. Our first results will be shown in this poster.

Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors

PubMed Central

Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz; Riahi, Siavash

2008-01-01

Ionophore incorporated PVC membrane sensors are well-established analytical tools routinely used for the selective and direct measurement of a wide variety of different ions in complex biological and environmental samples. Potentiometric sensors have some outstanding advantages including simple design and operation, wide linear dynamic range, relatively fast response and rational selectivity. The vital component of such plasticized PVC members is the ionophore involved, defining the selectivity of the electrodes' complex formation. Molecular recognition causes the formation of many different supramolecules. Different types of supramolecules, like calixarenes, cyclodextrins and podands, have been used as a sensing material in the construction of ion selective sensors. Schiff's bases and crown ethers, which feature prominently in supramolecular chemistry, can be used as sensing materials in the construction of potentiometric ion selective electrodes. Up to now, more than 200 potentiometric membrane sensors for cations and anions based on Schiff's bases and crown ethers have been reported. In this review cation binding and anion complexes will be described. Liquid membrane sensors based on Schiff's bases and crown ethers will then be discussed. PMID:27879786

New insights into the coordination chemistry of Schiff bases derived from amino acids: Planar [Ni4] complexes with tyrosine side-chains

NASA Astrophysics Data System (ADS)

Muche, Simon; Hołyńska, Małgorzata

2017-08-01

Structure and properties of a rare metal complex of the chiral Schiff base ligand derived from ortho-vanillin and L-tyrosine are presented. This study is a continuation of research on ligands containing biologically compatible moieties. The ligand is also fully characterized in form of a sodium salt, in particular in solution, for the first time. The metal complex contains a unique bowl-shaped [Ni4] core. Its structure is investigated both in solution (ESI-MS, NMR) and in solid state (X-ray diffraction studies). Under certain conditions the complex can be isolated as crystalline DMF solvate which is studied in solid state.

Fluorescent chemosensor based on sensitive Schiff base for selective detection of Zn2+

NASA Astrophysics Data System (ADS)

Singh, T. Sanjoy; Paul, Pradip C.; Pramanik, Harun A. R.

2014-03-01

A Schiff-base fluorescent compound - N, N‧-bis(salicylidene)-1,2 - phenylenediamine (LH2) was synthesized and evaluated as a chemoselective Zn2+ sensor. Addition of Zn2+ to ethanol solution of LH2 resulted in a red shift with a pronounced enhancement in the fluorescence intensity. Moreover, other common alkali, alkaline earth and transition metal ions failed to induce response or minimal spectral changes. Notably, this chemosensor could distinguish clearly Zn2+ from Cd2+. Fluorescence studies on free Schiff base ligand LH2 and LH2 - Zn2+ complex reveal that the quantum yield strongly increases upon coordination. The stoichiometric ratio and association constant were evaluated using Benesi - Hildebrand relation giving 1:1 stoichiometry. This further corroborated 1:1 complex formation based on Job's plot analyses.

Novel polymer anchored Cr(III) Schiff base complexes: Synthesis, characterization and antimicrobial properties

NASA Astrophysics Data System (ADS)

Selvi, Canan; Nartop, Dilek

2012-09-01

New polymer-bound Schiff bases and Cr(III) complexes have been synthesized by the reaction of 4-benzyloxybenzaldehyde, polymer-bound with 2-aminophenol, 2-amino-4-chlorophenol and 2-amino-4-methylphenol. The structure of polymeric-Schiff bases and their Cr(III) complexes have been characterized by elemental analyses, magnetic measurements, IR, UV-Vis, TG-DTA and 1H-NMR. All these compounds have also been investigated for antibacterial activity by the well-diffusion method against Staphylococcus aureus (RSKK-07035), Shigella dysenteria type 10 (RSKK 1036), Listeria monocytogenes 4b(ATCC 19115, Escherichia coli (ATCC 1230), Salmonella typhi H (NCTC 901.8394), Staphylococcus epidermis (ATCC 12228), Brucella abortus (RSKK-03026), Micrococcs luteus (ATCC 93419, Bacillus cereus sp., Pseudomonas putida sp. and for antifungal activity against Candida albicans (Y-1200-NIH).

Primary Pulmonary Ewing's Sarcoma/Primitive Neuroectodermal Tumor in a 67-year-old Man

PubMed Central

Lee, Yoon Young; Kim, Do Hoon; Lee, Ji Hye; Choi, Jong Sang; In, Kwang Ho; Oh, Yu Whan; Cho, Kyung Hwan

2007-01-01

Extraskeletal Ewing's sarcoma (EES) is a branch of neuroectodermal tumor (PNET), which is very rare soft tissue sarcoma. We report a case of EES/PNET arising is the lung of a 67-yr-old man. Computed tomography, bone scintigraphy, and positron emission tomography confirmed the mass to have a primary pulmonary origin. The mass showed positive reactivity in the Periodic Acid Schiff (PAS) stain and MIC-2 immunoreactivity in immunohistochemical stain. Fluorescence in situ hybridization (FISH) was performed, which revealed an EWSR1 (Ewing sarcoma breakpoint region 1) 22q12 rearrangement. The diagnosis was confirmed both pathologically and genetically. The mass lesion was resected, and the patient is currently undergoing chemotherapy. PMID:17923745

Water-soluble Schiff base-actinyl complexes and their effect on the solvent extraction of f-elements

DOE PAGES

Hawkins, Cory A.; Bustillos, Christian G.; May, Iain; ...

2016-09-07

Conventional solvent extraction of selected f-element cations by bis(2-ethylhexyl)phosphoric acid (HDEHP) yields increased extraction from aqueous to organic solution along the series Np(V) < Cm(III) < Eu(III) < U(VI), with distribution ratios all within two orders of magnitude. However, in the presence of the water-soluble tetradentate Schiff base (N,N'-bis(5-sulfonatosalicylidene)-ethylenediamine or H 2salenSO 3), selective complexation of the two actinyl cations (Np(V) and U(VI)) resulted in an extraction order of Np(V) < U(VI) << Eu(III) < Cm(III). The extraction of neither Cm(III) or Eu(III) by HDEHP are significantly impacted by the presence of the aqueous phase Schiff base. Despite observed hydrolyticmore » decomposition of H 2salenSO 3 in aqueous solutions, the calculated high conditional stability constant (β 11 = 26) for the complex [UO 2(salenSO 3)] 2- demonstrates its capacity for aqueous hold-back of U(VI). UV-visible-NIR spectroscopy of solutions prepared with a Np(VI) stock and H 2salenSO 3 suggest that reduction of Np(VI) to Np(V) by the ligand was rapid, resulting in a pentavalent Np complex that was substantially retained in the aqueous phase. Lastly, results from 1H NMR of aqueous solutions of H 2salenSO 3 with U(VI) and La(III), Eu(III), and Lu(III) provides additional evidence that the ligand readily chelates U(VI), but has only weak interactions with trivalent lanthanide ions.« less

Schiff Bases of Benzothiazol-2-ylamine and Thiazolo[5,4-b] pyridin-2-ylamine as Anticonvulsants: Synthesis, Characterization and Toxicity Profiling.

PubMed

Shukla, Rashmi; Singh, Ajeet P; Sonar, Pankaj K; Mishra, Mudita; Saraf, Shailendra K

2016-01-01

Schiff bases have a broad spectrum of biological activities like antiinflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic and so forth. Thus, after a thorough perusal of literature, it was decided to conjugate benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine with aromatic and heteroaromatic aldehydes to get a series of Schiff bases. Synthesis, characterization, in-silico toxicity profiling and anticonvulsant activity of the Schiff bases of Benzothiazol-2-ylamine and Thiazolo [5, 4-b] pyridin-2-ylamine. Aniline/4-aminopyridine was converted to the corresponding thiourea derivatives, which were cyclized to obtain benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine. Finally, these were condensed with various aromatic and heteroaromatic aldehydes to obtain Schiff bases of benzothiazol-2-ylamine and thiazolo [5, 4-b] pyridin-2-ylamine. The synthesized compounds were characterized and screened for their anticonvulsant activity using maximal electroshock (MES) test and isoniazid (INH) induced convulsions test. In-silico toxicity profiling of all the synthesized compounds was done through "Lazar" and "Osiris" properties explorer. Majority of the compounds were more potent against MES induced convulsions than INH induced convulsions. Schiff bases of benzothiazol-2-ylamine were more effective than thiazolo [5, 4-b] pyridin-2-ylamine against MES induced convulsions. The compound benzothiazol-2-yl-(1H-indol-2-ylmethylene)-amine (VI) was the most potent member of the series against both types of convulsions. Compound VI exhibited the most significant activity profile in both the models. The compounds did not exhibit any carcinogenicity or acute toxicity in the in-silico studies. Thus, it may be concluded that the Schiff bases of benzothiazol-2-ylamine exhibit the potential to be promising and non-toxic anticonvulsant agents.

Pyrrolizidine alkaloids (PAs) in honey and pollen-legal regulation of PA levels in food and animal feed required.

PubMed

Kempf, Michael; Reinhard, Annika; Beuerle, Till

2010-01-01

Pyrrolizidine alkaloids (PAs) are secondary plant constituents that comprise about 400 different structures and occur in two major forms, a tertiary form and the corresponding N-oxide. PAs containing a 1,2-double bond are pre-toxins and metabolically activated by the action of hepatic P-450 enzymes to toxic pyrroles. Besides the acute toxic effects, the genotoxic and tumorigenicity potential of PAs was demonstrated in some eukaryotic model systems. Recently, the potential PA contamination of food and feeding stuff attracted recurrent great deals of attention. Humans are exposed to these toxins by consumption of herbal medicine, herbal teas, dietary supplements or food containing PA plant material. In numerous studies the potential threat to human health by PAs is stated. In pharmaceuticals, the use of these plants is regulated. Considering the PA concentrations observed especially in authentic honey from PA producing plants and pollen products, the results provoke an international regulation of PAs in food.

Theoretical study on the optical response behavior to hydrogen chloride gas of a series of Schiff-base-based star-shaped structures.

PubMed

Wang, Fei; Qi, Tianhong; Su, Zhongmin; Xie, Yuzhong

2018-02-17

Schiff-base compounds have many applications in the field of optoelectronic materials and chemical sensing because of their appealing coordination ability, and simple and easily accessible use in structural modification. Herein, five kinds of star-shaped Schiff-base compounds were designed and their optical response behavior to hydrogen chloride (HCl) gas was studied using dependent/time-dependent density functional theory (DFT/TDDFT). Moreover, the relationship between structures and properties was investigated upon changing the benzene group into N atom or triazine group at the core-position and introducing a methoxyl (-OCH 3 ) or nitro (-NO 2 ) group into the star-shaped Schiff-bases at the tail of the branches. The results show that all five Schiff-bases could be candidates for HCl gas sensing materials. Furthermore, introducing an electron-donating group at either the core or the tail forms a charge transfer channel with the electron deficient H-bonded imino group, which is convenient for charge transfer and subsequently promotes a red-shift in absorption spectra and fluorescence quenching.

Metal based biologically active compounds: design, synthesis, and antibacterial/antifungal/cytotoxic properties of triazole-derived Schiff bases and their oxovanadium(IV) complexes.

PubMed

Chohan, Zahid H; Sumrra, Sajjad H; Youssoufi, Moulay H; Hadda, Taibi B

2010-07-01

A new series of oxovanadium(IV) complexes have been designed and synthesized with a new class of triazole Schiff bases derived from the reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde and acetyl pyridine-2-carboxaldehyde, respectively. Physical (magnetic susceptibility, molar conductance), spectral (IR, (1)H NMR, (13)C NMR, mass and electronic) and analytical data have established the structures of these synthesized Schiff bases and their oxovanadium(IV) complexes. The Schiff bases, predominantly act as bidentate and coordinate with the vanadium(IV) metal to give a stoichiometric ratio of 1:2 [M:L], forming a general formulae, [M(L-H)(2)] and [M(L)(2)]SO(4) where L = (L(1))-(L(4)) and M = VO(IV) of these complexes in a square-pyramidal geometry. In order to evaluate the biological activity of Schiff bases and to assess the role of vanadium(IV) metal on biological activity, the triazole Schiff bases and their oxovanadium(IV) complexes have been studied for in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexenari, Pseudomonas aeruginosa, Salmonella typhi) and two Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacterial strains, in vitro antifungal activity against Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani and Candida glaberata. The simple Schiff bases showed weaker to significant activity against one or more bacterial and fungal strains. In most of the cases higher activity was exhibited upon coordination with vanadium(IV) metal. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Exploratory studies of extended storage of apheresis platelets in a platelet additive solution (PAS)

PubMed Central

Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Pellham, Esther; Bailey, S. Lawrence; Bolgiano, Doug

2014-01-01

To evaluate the poststorage viability of apheresis platelets stored for up to 18 days in 80% platelet additive solution (PAS)/20% plasma, 117 healthy subjects donated platelets using the Haemonetics MCS+, COBE Spectra (Spectra), or Trima Accel (Trima) systems. Control platelets from the same subjects were compared with their stored test PAS platelets by radiolabeling their stored and control platelets with either 51chromium or 111indium. Trima platelets met Food and Drug Administration poststorage platelet viability criteria for only 7 days vs almost 13 days for Haemonetics platelets; ie, platelet recoveries after these storage times averaged 44 ± 3% vs 49 ± 3% and survivals were 5.4 ± 0.3 vs 4.6 ± 0.3 days, respectively. The differences in storage duration are likely related to both the collection system and the storage bag. The Spectra and Trima platelets were hyperconcentrated during collection, and PAS was added, whereas the Haemonetics platelets were elutriated with PAS, which may have resulted in less collection injury. When Spectra and Trima platelets were stored in Haemonetics’ bags, poststorage viability was significantly improved. Platelet viability is better maintained in vitro than in vivo, allowing substantial increases in platelet storage times. However, implementation will require resolution of potential bacterial overgrowth during storage. PMID:24258816

Synthesis, spectroscopic characterization and pH dependent photometric and electrochemical fate of Schiff bases.

PubMed

Rauf, Abdur; Shah, Afzal; Abbas, Saghir; Rana, Usman Ali; Khan, Salah Ud-Din; Ali, Saqib; Zia-Ur-Rehman; Qureshi, Rumana; Kraatz, Heinz-Bernhard; Belanger-Gariepy, Francine

2015-03-05

A new Schiff base, 1-((4-bromophenylimino) methyl) naphthalen-2-ol (BPIMN) was successfully synthesized and characterized by (1)H NMR, (13)C NMR, FTIR and UV-Vis spectroscopy. The results were compared with a structurally related Schiff base, 1-((4-chlorophenylimino) methyl) naphthalen-2-ol (CPIMN). The photometric and electrochemical fate of BPIMN and CPIMN was investigated in a wide pH range. The experimental findings were supported by quantum mechanical approach. The redox mechanistic pathways were proposed on the basis of results obtained electrochemical techniques. Moreover, pH dependent UV-Vis spectroscopy of BPIMN and CPIMN was carried out and the appearance of isosbestic points indicated the existence of these compounds in different tautomeric forms. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis, characterization, crystal structure and HSA binding of two new N,O,O-donor Schiff-base ligands derived from dihydroxybenzaldehyde and tert-butylamine

NASA Astrophysics Data System (ADS)

Khosravi, Iman; Hosseini, Farnaz; Khorshidifard, Mahsa; Sahihi, Mehdi; Rudbari, Hadi Amiri

2016-09-01

Two new o-hydroxy Schiff-bases compounds, L1 and L2, were derived from the 1:1 M condensation of 2,3-dihydroxybenzaldehyde and 2,4-dihydroxybenzaldehyde with tert-butylamine and were characterized by elemental analysis, FT-IR, 1H and 13C NMR spectroscopies. The crystal structure of L2 was also determined by single crystal X-ray analysis. The crystal structure of L2 showed that the compound exists as a zwitterionic form in the solid state, with the H atom of the phenol group being transferred to the imine N atom. It adopts an E configuration about the central Cdbnd N double bond. Furthermore, binding of these Schiff base ligands to Human Serum Albumin (HSA) was investigated by fluorescence quenching, absorption spectroscopy, molecular docking and molecular dynamics (MD) simulation methods. The fluorescence emission of HSA was quenched by ligands. Also, suitable models were used to analyze the UV-vis absorption spectroscopy data for titration of HSA solution by various amounts of Schiff bases. The spectroscopic studies revealed that these Schiff bases formed 1:1 complex with HSA. Energy transfer mechanism of quenching was discussed and the values of 3.35 and 1.57 nm as the mean distances between the bound ligands and the HSA were calculated for L1 and L2, respectively. Molecular docking results indicated that the main active binding site for these Schiff bases ligands is in subdomain IB. Moreover, MD simulation results suggested that this Schiff base complex can interact with HSA, with a slight modification of its tertiary structure.

Charge transfer complexes of adenosine-5‧-monophosphate and cytidine-5‧-monophosphate with water-soluble cobalt(II) Schiff base complexes in aqueous solution

NASA Astrophysics Data System (ADS)

Boghaei, Davar M.; Gharagozlou, Mehrnaz

2006-01-01

Water-soluble cobalt(II) tetradentate Schiff base complexes have been shown to form charge transfer (CT) complexes with a series of nucleoside monophosphates including adenosine-5‧-monophosphate (AMP) and cytidine-5‧-monophosphate (CMP). The investigated water-soluble cobalt(II) Schiff base complexes are (i) disodium[{bis(5-sulfo-salicylaldehyde)-o-phenylenediiminato}cobalt(II)], Na2[Co(SO3-salophen)] (1); (ii) disodium[{bis(5-sulfo-salicylaldehyde)-4,5-dimethyl-o-phenylenediiminato}cobalt(II)], Na2[Co(SO3-sal-4,5-dmophen)] (2) and (iii) disodium[{bis(4-methoxy-5-sulfo-salicylaldehyde)-4,5-dimethyl-o-phenylenediiminato}cobalt(II)], Na2[Co(SO3-4-meosal-4,5-dmophen)] (3). The formation constant and thermodynamic parameters for charge transfer complex formation of water-soluble cobalt(II) Schiff base complexes with nucleoside monophosphates were determined spectrophotometrically in aqueous solution at constant ionic strength (I = 0.2 mol dm-3 KNO3) under physiological condition (pH 7.0) and at various temperatures between 288 and 308 K. The stoichiometry has been found to be 1:1 (water-soluble cobalt(II) Schiff base complex: nucleoside monophosphate) in each case. Our spectroscopic and thermodynamic results show that the interaction of water-soluble cobalt(II) Schiff base complexes with the investigated nucleoside monophosphates occurs mainly through the phosphate group. The trend of the interaction according to the cobalt(II) Schiff base complexes due to electronic and steric factors is as follows: Na2[Co(SO3-salophen)] > Na2[Co(SO3-sal-4,5-dmophen)] > Na2[Co(SO3-4-meosal-4,5-dmophen)]. Also the trend of the interaction of a given cobalt(II) Schiff base complex according to the nucleoside monophosphate is as follows: CMP > AMP.

Design and synthesis of binucleating macrocyclic clefts derived from Schiff-base calixpyrroles.

PubMed

Givaja, Gonzalo; Volpe, Manuel; Leeland, James W; Edwards, Michael A; Young, Thomas K; Darby, S Barnie; Reid, Stuart D; Blake, Alexander J; Wilson, Claire; Wolowska, Joanna; McInnes, Eric J L; Schröder, Martin; Love, Jason B

2007-01-01

The syntheses, characterisation and complexation reactions of a series of binucleating Schiff-base calixpyrrole macrocycles are described. The acid-templated [2+2] condensations between meso-disubstituted diformyldipyrromethanes and o-phenylenediamines generate the Schiff-base pyrrolic macrocycles H(4)L(1) to H(4)L(6) upon basic workup. The single-crystal X-ray structures of both H(4)L(3).2 EtOH and H(4)L(6).H2O confirm that [2+2] cyclisation has occurred, with either EtOH or H2O hydrogen-bonded within the macrocyclic cleft. A series of complexation reactions generate the dipalladium [Pd2(L)] (L=L(1) to L(5)), dinickel [Ni2(L(1))] and dicopper [Cu2(L)] (L=L(1) to L(3)) complexes. All of these complexes have been structurally characterised in the solid state and are found to adopt wedged structures that are enforced by the rigidity of the aryl backbone to give a cleft reminiscent of the structures of Pacman porphyrins. The binuclear nickel complexes [Ni2(mu-OMe)2Cl2(HOMe)2(H(4)L(1))] and [Ni2(mu-OH)2Cl2(HOMe)(H(4)L(5))] have also been prepared, although in these cases the solid-state structures show that the macrocyclic ligand remains protonated at the pyrrolic nitrogen atoms, and the Ni(II) cations are therefore co-ordinated by the imine nitrogen atoms only to give an open conformation for the complex. The dicopper complex [Cu2(L(3))] was crystallised in the presence of pyridine to form the adduct [Cu2(py)(L(3))], in which, in the solid state, the pyridine ligand is bound within the binuclear molecular cleft. Reaction between H(4)L(1) and [Mn(thf){N(SiMe(3))2}2] results in clean formation of the dimanganese complex [Mn2(L(1))], which, upon crystallisation, formed the mixed-valent complex [Mn2(mu-OH)(L(1))] in which the hydroxo ligand bridges the metal centres within the molecular cleft.

Chemopreventive evaluation of a Schiff base derived copper (II) complex against azoxymethane-induced colorectal cancer in rats.

PubMed

Hajrezaie, Maryam; Hassandarvish, Pouya; Moghadamtousi, Soheil Zorofchian; Gwaram, Nura Suleiman; Golbabapour, Shahram; Najihussien, Abdrabuh; Almagrami, Amel Abdullah; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Fani, Somaye; Kamalidehghan, Behnam; Majid, Nazia Abdul; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen

2014-01-01

Based on the potential of Schiff base compounds to act as sources for the development of cancer chemotherapeutic agents, this in vivo study was performed to investigate the inhibitory properties of the synthetic Schiff base compound Cu(BrHAP)2 on colonic aberrant crypt foci (ACF). This study involved five groups of male rats. The negative control group was injected with normal saline once a week for 2 weeks and fed 10% Tween 20 for 10 weeks, the cancer control group was subcutaneously injected with 15 mg/kg azoxymethane once per week for two consecutive weeks, the positive control group was injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and 35 mg/kg 5-fluorouracil (injected intra-peritoneally) for 4 weeks, and the experimental groups were first injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and then fed 2.5 or 5 mg/kg of the Schiff base compound once a day for 10 weeks. Application of the Schiff base compound suppressed total colonic ACF formation by up to 72% to 74% (P<0.05) when compared with the cancer control group. Analysis of colorectal specimens revealed that treatments with the Schiff base compound decreased the mean crypt scores in azoxymethane-treated rats. Significant elevations of superoxide dismutase, glutathione peroxidase and catalase activities and a reduction in the level of malondialdehyde were also observed. Histologically, all treatment groups exhibited significant decreases in dysplasia compared to the cancer control group (P<0.05). Immunohistochemical staining demonstrated down-regulation of the PCNA protein. Comparative western blot analysis revealed that COX-2 and Bcl2 were up-regulated and Bax was down-regulated compared with the AOM control group. The current study demonstrated that the Cu(BrHAP)2 compound has promising chemoprotective activities that are evidenced by significant decreases in the numbers of ACFs in azoxymethane-induced colon cancer.

Chemopreventive Evaluation of a Schiff Base Derived Copper (II) Complex against Azoxymethane-Induced Colorectal Cancer in Rats

PubMed Central

Hajrezaie, Maryam; Hassandarvish, Pouya; Moghadamtousi, Soheil Zorofchian; Gwaram, Nura Suleiman; Golbabapour, Shahram; NajiHussien, Abdrabuh; Almagrami, Amel Abdullah; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Fani, Somaye; Kamalidehghan, Behnam; Majid, Nazia Abdul; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen

2014-01-01

Background Based on the potential of Schiff base compounds to act as sources for the development of cancer chemotherapeutic agents, this in vivo study was performed to investigate the inhibitory properties of the synthetic Schiff base compound Cu(BrHAP)2 on colonic aberrant crypt foci (ACF). Methodology This study involved five groups of male rats. The negative control group was injected with normal saline once a week for 2 weeks and fed 10% Tween 20 for 10 weeks, the cancer control group was subcutaneously injected with 15 mg/kg azoxymethane once per week for two consecutive weeks, the positive control group was injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and 35 mg/kg 5-fluorouracil (injected intra-peritoneally) for 4 weeks, and the experimental groups were first injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and then fed 2.5 or 5 mg/kg of the Schiff base compound once a day for 10 weeks. Application of the Schiff base compound suppressed total colonic ACF formation by up to 72% to 74% (P<0.05) when compared with the cancer control group. Analysis of colorectal specimens revealed that treatments with the Schiff base compound decreased the mean crypt scores in azoxymethane-treated rats. Significant elevations of superoxide dismutase, glutathione peroxidase and catalase activities and a reduction in the level of malondialdehyde were also observed. Histologically, all treatment groups exhibited significant decreases in dysplasia compared to the cancer control group (P<0.05). Immunohistochemical staining demonstrated down-regulation of the PCNA protein. Comparative western blot analysis revealed that COX-2 and Bcl2 were up-regulated and Bax was down-regulated compared with the AOM control group. Conclusion The current study demonstrated that the Cu(BrHAP)2 compound has promising chemoprotective activities that are evidenced by significant decreases in the numbers of ACFs in azoxymethane-induced colon cancer

Constitutive signaling by the phototaxis receptor sensory rhodopsin II from disruption of its protonated Schiff base–Asp-73 interhelical salt bridge

PubMed Central

Spudich, Elena N.; Zhang, Weisheng; Alam, Maqsudul; Spudich, John L.

1997-01-01

Sensory rhodopsin II (SRII) is a repellent phototaxis receptor in the archaeon Halobacterium salinarum, similar to visual pigments in its seven-helix structure and linkage of retinal to the protein by a protonated Schiff base in helix G. Asp-73 in helix C is shown by spectroscopic analysis to be a counterion to the protonated Schiff base in the unphotolyzed SRII and to be the proton acceptor from the Schiff base during photoconversion to the receptor signaling state. Coexpression of the genes encoding mutated SRII with Asn substituted for Asp-73 (D73N) and the SRII transducer HtrII in H. salinarum cells results in a 3-fold higher swimming reversal frequency accompanied by demethylation of HtrII in the dark, showing that D73N SRII produces repellent signals in its unphotostimulated state. Analogous constitutive signaling has been shown to be produced by the similar neutral residue substitution of the Schiff base counterion and proton acceptor Glu-113 in human rod rhodopsin. The interpretation for both seven-helix receptors is that light activation of the wild-type protein is caused primarily by photoisomerization-induced transfer of the Schiff base proton on helix G to its primary carboxylate counterion on helix C. Therefore receptor activation by helix C–G salt-bridge disruption in the photoactive site is a general mechanism in retinylidene proteins spanning the vast evolutionary distance between archaea and humans. PMID:9144172

Three VO2+ complexes of the pyridoxal-derived Schiff bases: Synthesis, experimental and theoretical characterizations, and catalytic activity in a cyclocondensation reaction

NASA Astrophysics Data System (ADS)

Jafari-Moghaddam, Faezeh; Beyramabadi, S. Ali; Khashi, Maryam; Morsali, Ali

2018-02-01

Three oxovanadium(IV) complexes of the pyridoxal Schiff bases have been newly synthesized and characterized. The used Schiff bases were N,N‧-dipyridoxyl(ethylenediamine), N,N‧-dipyridoxyl(1,3-propanediamine) and N,N‧-dipyridoxyl(1,2-benzenediamine). Also, the optimized geometry, assignment of the IR bands and the Natural Bond Orbital (NBO) analysis of the complexes have been computed using the density functional theory (DFT) methods. Dianionic form of the Schiff bases (L2-) acts as a tetradentate N2O2 ligand. The coordinating atoms of the Schiff base are the phenolate oxygens and imine nitrogens, which occupy four base positions of the square-pyramidal geometry of the complexes. The oxo ligand occupies the apical position of the [VO(L)] complexes. In the optimized geometry of the complexes, the coordinated Schiff bases have more planar structure than their free form. Due to the high-energy gaps, all of the complexes are predicted to be stable. Good agreement between the experimental values and the DFT-computed results supports suitability of the optimized geometries for the complexes. The investigated complexes show high catalytic activities in synthesis of the tetrahydrobenzo[b]pyrans through a three-component cyclocondensation reaction of dimedone, malononitrile and some aromatic aldehydes. The complexes catalyzed the reaction in solvent free conditions and the catalysts were found to be reusable.

Specific Inhibition of the transcription factor Ci by a Cobalt(III)-Schiff base-DNA conjugate

PubMed Central

Hurtado, Ryan R.; Harney, Allison S.; Heffern, Marie C.; Holbrook, Robert J.; Holmgren, Robert A.; Meade, Thomas J.

2012-01-01

We describe the use of Co(III) Schiff base-DNA conjugates, a versatile class of research tools that target C2H2 transcription factors, to inhibit the Hedgehog (Hh) pathway. In developing mammalian embryos, Hh signaling is critical for the formation and development of many tissues and organs. Inappropriate activation of the Hedgehog (Hh) pathway has been implicated in a variety of cancers including medulloblastomas and basal cell carcinomas. It is well known that Hh regulates the activity of the Gli family of C2H2 zinc finger transcription factors in mammals. In Drosophila the function of the Gli proteins is performed by a single transcription factor with an identical DNA binding consensus sequence, Cubitus Interruptus (Ci). We have demonstrated previously that conjugation of a specific 17 base-pair oligonucleotide to a Co(III) Schiff base complex results in a targeted inhibitor of the Snail family C2H2 zinc finger transcription factors. Modification of the oligonucleotide sequence in the Co(III) Schiff base-DNA conjugate to that of Ci’s consensus sequence (Co(III)-Ci) generates an equally selective inhibitor of Ci. Co(III)-Ci irreversibly binds the Ci zinc finger domain and prevents it from binding DNA in vitro. In a Ci responsive tissue culture reporter gene assay, Co(III)-Ci reduces the transcriptional activity of Ci in a concentration dependent manner. In addition, injection of wild-type Drosophila embryos with Co(III)-Ci phenocopies a Ci loss of function phenotype, demonstrating effectiveness in vivo. This study provides evidence that Co(III) Schiff base-DNA conjugates are a versatile class of specific and potent tools for studying zinc finger domain proteins and have potential applications as customizable anti-cancer therapeutics. PMID:22214326

Antimycobacterial, antimicrobial, and biocompatibility properties of para-aminosalicylic acid with zinc layered hydroxide and Zn/Al layered double hydroxide nanocomposites

PubMed Central

Saifullah, Bullo; El Zowalaty, Mohamed E; Arulselvan, Palanisamy; Fakurazi, Sharida; Webster, Thomas J; Geilich, Benjamin M; Hussein, Mohd Zobir

2014-01-01

The treatment of tuberculosis by chemotherapy is complicated due to multiple drug prescriptions, long treatment duration, and adverse side effects. We report here for the first time an in vitro therapeutic effect of nanocomposites based on para-aminosalicylic acid with zinc layered hydroxide (PAS-ZLH) and zinc-aluminum layered double hydroxides (PAS-Zn/Al LDH), against mycobacteria, Gram-positive bacteria, and Gram-negative bacteria. The nanocomposites demonstrated good antimycobacterial activity and were found to be effective in killing Gram-positive and Gram-negative bacteria. A biocompatibility study revealed good biocompatibility of the PAS-ZLH nanocomposites against normal human MRC-5 lung cells. The para-aminosalicylic acid loading was quantified with high-performance liquid chromatography analysis. In summary, the present preliminary in vitro studies are highly encouraging for further in vivo studies of PAS-ZLH and PAS-Zn/Al LDH nanocomposites to treat tuberculosis. PMID:25114509

The Zinc-Schiff Base-Novicidin Complex as a Potential Prostate Cancer Therapy

PubMed Central

Milosavljevic, Vedran; Haddad, Yazan; Merlos Rodrigo, Miguel Angel; Moulick, Amitava; Polanska, Hana; Hynek, David; Heger, Zbynek; Kopel, Pavel; Adam, Vojtech

2016-01-01

Prostate cancer cells control energy metabolism by chelating intracellular zinc. Thus, zinc delivery has been a popular therapeutic approach for prostate cancer. Here, we propose the use of the membrane-penetrating peptide Novicidin connected to zinc-Schiff base as a carrier vehicle for the delivery of zinc to prostate cells. Mass spectrometry, electrochemistry and spectrophotometry confirmed the formation/stability of this complex and provided insight regarding the availability of zinc for complex interactions. This delivery system showed minor toxicity in normal PNT1A cells and high potency towards PC3 tumor cells. The complex preferentially penetrated PC3 tumor cells in contrast to confinement to the membranes of PNT1A. Furthermore, zinc uptake was confirmed in both cell lines. Molecular analysis was used to confirm the activation of zinc stress (e.g., ZnT-1) and apoptosis (e.g., CASP-1). Our results strongly suggest that the zinc-Schiff base-Novicidin complex has great potential as a novel anticancer drug. PMID:27727290

Synthesis, X-ray crystallography, thermal studies, spectroscopic and electrochemistry investigations of uranyl Schiff base complexes.

PubMed

Asadi, Zahra; Shorkaei, Mohammad Ranjkesh

2013-03-15

Some tetradentate salen type Schiff bases and their uranyl complexes were synthesized and characterized by UV-Vis, NMR, IR, TG, C.H.N. and X-ray crystallographic studies. From these investigations it is confirmed that a solvent molecule occupied the fifth position of the equatorial plane of the distorted pentagonal bipyramidal structure. Also, the kinetics of complex decomposition by using thermo gravimetric methods (TG) was studied. The thermal decomposition reactions are first order for the studied complexes. To examine the properties of uranyl complexes according to the substitutional groups, we have carried out the electrochemical studies. The electrochemical reactions of uranyl Schiff base complexes in acetonitrile were reversible. Copyright © 2012 Elsevier B.V. All rights reserved.

GIAO-DFT calculation of 15 N NMR chemical shifts of Schiff bases: Accuracy factors and protonation effects.

PubMed

Semenov, Valentin A; Samultsev, Dmitry O; Krivdin, Leonid B

2018-02-09

15 N NMR chemical shifts in the representative series of Schiff bases together with their protonated forms have been calculated at the density functional theory level in comparison with available experiment. A number of functionals and basis sets have been tested in terms of a better agreement with experiment. Complimentary to gas phase results, 2 solvation models, namely, a classical Tomasi's polarizable continuum model (PCM) and that in combination with an explicit inclusion of one molecule of solvent into calculation space to form supermolecule 1:1 (SM + PCM), were examined. Best results are achieved with PCM and SM + PCM models resulting in mean absolute errors of calculated 15 N NMR chemical shifts in the whole series of neutral and protonated Schiff bases of accordingly 5.2 and 5.8 ppm as compared with 15.2 ppm in gas phase for the range of about 200 ppm. Noticeable protonation effects (exceeding 100 ppm) in protonated Schiff bases are rationalized in terms of a general natural bond orbital approach. Copyright © 2018 John Wiley & Sons, Ltd.

A Quantum Chemical and Statistical Study of Phenolic Schiff Bases with Antioxidant Activity against DPPH Free Radical

PubMed Central

Anouar, El Hassane

2014-01-01

Phenolic Schiff bases are known as powerful antioxidants. To select the electronic, 2D and 3D descriptors responsible for the free radical scavenging ability of a series of 30 phenolic Schiff bases, a set of molecular descriptors were calculated by using B3P86 (Becke’s three parameter hybrid functional with Perdew 86 correlation functional) combined with 6-31 + G(d,p) basis set (i.e., at the B3P86/6-31 + G(d,p) level of theory). The chemometric methods, simple and multiple linear regressions (SLR and MLR), principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to reduce the dimensionality and to investigate the relationship between the calculated descriptors and the antioxidant activity. The results showed that the antioxidant activity mainly depends on the first and second bond dissociation enthalpies of phenolic hydroxyl groups, the dipole moment and the hydrophobicity descriptors. The antioxidant activity is inversely proportional to the main descriptors. The selected descriptors discriminate the Schiff bases into active and inactive antioxidants. PMID:26784873

Laser diode bars based on strain-compensated AlGaPAs/GaAs heterostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marmalyuk, Aleksandr A; Ladugin, M A; Yarotskaya, I V

2012-01-31

Traditional (in the AlGaAs/GaAs system) and phosphorus-compensated (in the AlGaAs/AlGaPAs/GaAs system) laser heterostructures emitting at a wavelength of 850 nm are grown by MOVPE and studied. Laser diode bars are fabricated and their output characteristics are studied. The method used to grow heterolayers allowed us to control (minimise) mechanical stresses in the AlGaPAs/GaAs laser heterostructure, which made it possible to keep its curvature at the level of the initial curvature of the substrate. It is shown that the use of a compensated AlGaPAs/GaAs heterostructure improves the linear distribution of emitting elements in the near field of laser diode arrays andmore » allows the power - current characteristic to retain its slope at high pump currents owing to a uniform contact of all emitting elements with the heat sink. The radius of curvature of the grown compensated heterostructures turns out to be smaller than that of traditional heterostructures.« less

Rational design of a colorimetric pH sensor from a soluble retinoic acid chaperone.

PubMed

Berbasova, Tetyana; Nosrati, Meisam; Vasileiou, Chrysoula; Wang, Wenjing; Lee, Kin Sing Stephen; Yapici, Ipek; Geiger, James H; Borhan, Babak

2013-10-30

Reengineering of cellular retinoic acid binding protein II (CRABPII) to be capable of binding retinal as a protonated Schiff base is described. Through rational alterations of the binding pocket, electrostatic perturbations of the embedded retinylidene chromophore that favor delocalization of the iminium charge lead to exquisite control in the regulation of chromophoric absorption properties, spanning the visible spectrum (474-640 nm). The pKa of the retinylidene protonated Schiff base was modulated from 2.4 to 8.1, giving rise to a set of proteins of varying colors and pH sensitivities. These proteins were used to demonstrate a concentration-independent, ratiometric pH sensor.

Comparison of multi-fiber reproducibility of PAS-MRI and Q-ball with empirical multiple b-value HARDI

NASA Astrophysics Data System (ADS)

Nath, Vishwesh; Schilling, Kurt G.; Blaber, Justin A.; Ding, Zhaohua; Anderson, Adam W.; Landman, Bennett A.

2017-02-01

Crossing fibers are prevalent in human brains and a subject of intense interest for neuroscience. Diffusion tensor imaging (DTI) can resolve tissue orientation but is blind to crossing fibers. Many advanced diffusion-weighted magnetic resolution imaging (MRI) approaches have been presented to extract crossing-fibers from high angular resolution diffusion imaging (HARDI), but the relative sensitivity and specificity of approaches remains unclear. Here, we examine two leading approaches (PAS and q-ball) in the context of a large-scale, single subject reproducibility study. A single healthy individual was scanned 11 times with 96 diffusion weighted directions and 10 reference volumes for each of five b-values (1000, 1500, 2000, 2500, 3000 s/mm2) for a total of 5830 volumes (over the course of three sessions). We examined the reproducibility of the number of fibers per voxel, volume fraction, and crossing-fiber angles. For each method, we determined the minimum resolvable angle for each acquisition. Reproducibility of fiber counts per voxel was generally high ( 80% consensus for PAS and 70% for q-ball), but there was substantial bias between individual repetitions and model estimated with all data ( 10% lower consensus for PAS and 15% lower for q-ball). Both PAS and q-ball predominantly discovered fibers crossing at near 90 degrees, but reproducibility was higher for PAS across most measures. Within voxels with low anisotropy, q-ball finds more intra-voxel structure; meanwhile, PAS resolves multiple fibers at greater than 75 degrees for more voxels. These results can inform researchers when deciding between HARDI approaches or interpreting findings across studies.

Synthesis, Characterization and Biological Activities of Creatinine Amides and Creatinine Schiff Bases.

PubMed

Mumtaz, Amara; Zahoor, Fareeha; Zaib, Sumera; Nawaz, Muhammad Azhar H; Saeed, Aamer; Waseem, Amir; Khan, Afsar; Hussain, Izhar; Iqbal, Jamshed

2017-01-30

In spite of substantial progress in scientific cognizance and medical technology, still infectious diseases are among the leading cause of morbidity and mortality. Creatinine and Schiff bases are well known for their diverse range of biological activities and thought to be emerging and useful therapeutic target for the treatment of several diseases. The present work was aimed to illustrate the influence of substitution of amides and Schiff bases on creatinine and their antimicrobial, antioxidant and anti-urease effectiveness was determined. Creatinine substituted amides (1-2) and creatinine Schiff bases (3-7) were synthesized and characterized by NMR and IR spectral data in combination with elemental analysis. All the compounds (1-7) were investigated on Jack bean urease for their urease inhibitory potential. Investigation of antimicrobial activity of the compounds was made by the agar dilution method. Moreover, 1,1-diphenyl-2- picrylhydrazyl (DPPH) method was used to determine their antioxidant potential. Molecular docking studies were also carried out to elucidate their relationship with the binding pockets of the enzyme. The compounds were found to be potent inhibitors of urease. The synthesized derivatives exhibited significant inhibition against Gram-positive and Gram-negative bacterial strains, as compared to standard, ciprofloxacin. Creatinine based derivatives exhibited potential antifungal activity when tested on infectious and pathogenic fungal strains. Similarly, most of the compounds exhibited good antioxidant activity. These derivatives may serve as a source of potential antioxidants and also help to retard microbial growth in food industry. Similarly, the studies provide a basis for further research to develop more potent urease inhibitory compounds of medicinal /agricultural interest. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Synthesis and structural features of U VI and V IV chelate complexes with (hhmmbH)Cl·H 2O [hhmmb = {3-hydroxyl-5-(hydroxymethyl)-2-methylpyridine-4-yl-methylene}benzohydrazide], a new Schiff base ligand derived from vitamin B6

NASA Astrophysics Data System (ADS)

Back, Davi Fernando; Ballin, Marco Aurélio; de Oliveira, Gelson Manzoni

2009-10-01

The Schiff base ligand {3-hydroxyl-5-(hydroxymethyl)-2-methylpyridine-4-yl-methylene}benzohydrazide hydrochloride monohydrated {(hhmmbH)Cl·H 2O} ( 1) was prepared by reaction of pyridoxine hydrochloride with benzoic acid hydrazide. The reaction of 1 with [VO(acac) 2] and triethylamine yields the neutral vanadium IV complex [VO 2(hhmmb)]·Py ( 2), with a distorted quadratic pyramidal configuration. The Schiff base 1 reacts also with UO 2(NO 3) 2·6H 2O and triethylamine under deprotonation giving the uranium VI cationic complexes [UO 2(hhmmb)(H 2O)Cl] + ( 3) and [UO 2(hhmmb)(CH 3OH)Cl] + ( 4), both showing the classical pentagonal bipyrimidal geometry of UO22+ complexes. The structural features of all compounds are discussed.

Evaluation of staining methods for cytologic diagnosis of oral lesions.

PubMed

Almeida, Janete Dias; Lima, Celina Faig; Brandão, Adriana Aigotti Haberbeck; Cabral, Luiz Antonio Guimarães

2008-01-01

To compare the efficacy ofPapanicolaou, hematoxylin-eosin (H-E), Leishman and periodic acid-Schiff (PAS) staining for cytologic diagnosis of oral lesions. Patients from the Discipline of Stomatology, São José dos Campos Dental School, from the wards of Hosapital Heliópolis and from the dentistry outpatient clinic of the University Hospital, University of São Paulo Medical School, with the following diseases, were selected: erythematous candidiasis (n=9), pseudomembranous candidiasis (n=10), squamous cell carcinoma (n=19), herpes simplex (n=8), paracoccidioidomycosis (n=8) and pemphigus vulgaris (n=1). The different staining methods were compared regarding the quality of definition of cytoplasmic and nuclear morphologic characteristics and the identification of bacteria, fungi, inflammatory cells and secretions. Papanicolaou and H-E staining were considered better methods. In cases of fungal infections, PAS staining is useful and should be applied as a complementary method. Within the limitations of this study, it can be concluded that the cytologic diagnosis of oral lesions along with different staining methods is a useful tool for oral diagnosis.

Clinical Manifestations, Treatment, and Diagnosis of Tropheryma whipplei Infections

PubMed Central

Dolmans, Ruben A. V.; Boel, C. H. Edwin; Lacle, Miangela M.

2017-01-01

SUMMARY Whipple's disease is a rare infectious disease that can be fatal if left untreated. The disease is caused by infection with Tropheryma whipplei, a bacterium that may be more common than was initially assumed. Most patients present with nonspecific symptoms, and as routine cultivation of the bacterium is not feasible, it is difficult to diagnose this infection. On the other hand, due to the generic symptoms, infection with this bacterium is actually quite often in the differential diagnosis. The gold standard for diagnosis used to be periodic acid-Schiff (PAS) staining of duodenal biopsy specimens, but PAS staining has a poor specificity and sensitivity. The development of molecular techniques has resulted in more convenient methods for detecting T. whipplei infections, and this has greatly improved the diagnosis of this often missed infection. In addition, the molecular detection of T. whipplei has resulted in an increase in knowledge about its pathogenicity, and this review gives an overview of the new insights in epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of Tropheryma whipplei infections. PMID:28298472

Metastatic iridociliary adenocarcinoma in a labrador retriever.

PubMed

Zarfoss, M K; Dubielzig, R R

2007-09-01

An enucleated left eye from a 15-year-old female spayed Labrador Retriever was received by the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) for histopathologic evaluation. Routine histologic preparation included staining with hematoxylin and eosin, and with alcian blue periodic acid-Schiff (PAS). At necropsy 9 months later, all grossly abnormal tissues (ipsilateral orbit and lung) were submitted to the COPLOW for histopathologic evaluation. Histopathologic evaluation of the globe revealed extensive invasion of the uvea and sclera by a pleomorphic cell population that formed disorganized cords and exhibited PAS-positive basement membrane material. Necropsy revealed a morphologically similar tumor in the ipsilateral orbit and lung. On immunohistochemical examination, the intraocular tumor stained diffusely immunopositive for vimentin, S-100, and neuron-specific enolase and multifocally, sparsely immunopositive for cytokeratin AE1/AE3. The orbital and thoracic tumors stained positively for vimentin but negatively for cytokeratin AE1/AE3. There are few reports of canine metastatic iridociliary adenocarcinoma in the literature; this is the first with immunohistochemical analysis.

Indole-3-acetic acid modulates phytohormones and polyamines metabolism associated with the tolerance to water stress in white clover.

PubMed

Li, Zhou; Li, Yaping; Zhang, Yan; Cheng, Bizhen; Peng, Yan; Zhang, Xinquan; Ma, Xiao; Huang, Linkai; Yan, Yanhong

2018-06-09

Endogenous hormones and polyamines (PAs) could interact to regulate growth and tolerance to water stress in white clover. The objective of this study was to investigate whether the alteration of endogenous indole-3-acetic acid (IAA) level affected other hormones level and PAs metabolism contributing to the regulation of tolerance to water stress in white clover. Plants were pretreated with IAA or L-2-aminooxy-3-phenylpropionic acid (L-AOPP, the inhibitor of IAA biosynthesis) for 3 days and then subjected to water-sufficient condition and water stress induced by 15% polyethylene glycol 6000 for 8 days in growth chambers. Exogenous application of IAA significantly increased endogenous IAA, gibberellin (GA), abscisic acid (ABA), and polyamine (PAs) levels, but had no effect on cytokinin content under water stress. The increase in endogenous IAA level enhanced PAs anabolism via the improvement of enzyme activities and transcript level of genes including arginine decarboxylase, ornithine decarboxylase, and S-adenosylmethionine decarboxylase. Exogenous application of IAA also affected PAs catabolism, as manifested by an increase in diamine oxidase and a decrease in polyamine oxidase activities and genes expression. More importantly, the IAA deficiency in white clover decreased endogenous hormone levels (GA, ABA, and PAs) and PAs anabolism along with decline in antioxidant defense and osmotic adjustment (OA). On the contrary, exogenous IAA effectively alleviated stress-induced oxidative damage, growth inhibition, water deficit, and leaf senescence through the maintenance of higher chlorophyll content, OA, and antioxidant defense as well as lower transcript levels of senescence marker genes SAG101 and SAG102 in leaves under water stress. These results indicate that IAA-induced the crosstalk between endogenous hormones and PAs could be involved in the improvement of antioxidant defense and OA conferring tolerance to water stress in white clover. Copyright © 2018 Elsevier

Anxiety in early Parkinson's disease: Validation of the Italian observer-rated version of the Parkinson Anxiety Scale (OR-PAS).

PubMed

Santangelo, Gabriella; Falco, Fabrizia; D'Iorio, Alfonsina; Cuoco, Sofia; Raimo, Simona; Amboni, Marianna; Pellecchia, Maria Teresa; Longo, Katia; Vitale, Carmine; Barone, Paolo

2016-08-15

Anxiety disorders are common in Parkinson's Disease (PD) and their identification is relevant even at early stages. The Parkinson Anxiety Scale (PAS) evaluates anxiety in PD; it was used only in the original validation study in PD patients mainly at 2-3 stages of Hoehn & Yahr system (H&Y). The study aimed to investigate psychometric properties of observer-rated version of the PAS (OR-PAS), prevalence rate of anxiety and its features, compared with diagnostic criteria in early PD patients. A sample of 101 PD patients with H&Y:1-2 underwent the OR-PAS. To assess convergent and divergent validity, PD patients underwent Beck Anxiety Inventory, and scales assessing depression, apathy, anhedonia and cognition. To diagnose anxiety disorders, Mini International Neuropsychiatric Inventory was used as gold standard. A "receiver operating characteristics" curve was obtained; positive and negative predictive values were calculated for different cut-off points of the OR-PAS and its subscales. There was no missing data, no floor and ceiling effects; mean score was 12.2±10.1; Cronbach's alpha was 0.899. The OR-PAS showed good convergent and divergent validity. Maximum discrimination was obtained with a cut-off score of 8.5. The anxiety occurred in 59 patients (58.4%). The OR-PAS is a reliable and valid screening instrument for assessing anxiety in patients at early PD. Anxiety was found in 58.4% of PD patients, demonstrating that anxiety occurs even at early stages. Copyright © 2016 Elsevier B.V. All rights reserved.

Pine beauty moth (Panolis flammea Schiff.) outbreak management: suppression versus natural enemies

Treesearch

Paulius Zolubas

2003-01-01

Pine beauty moth (Panolis flammea Schiff.) is one of the most serious defoliators that periodically threatens Scotch pine forests on poor sandy soils in Lithuania. Population increase of this pest began in 1999. Because a maximum of only 15% defoliation was predicted in particular areas, no additional funding was required for suppressing the...

Synthesis, characterization, and spectroscopic investigation of benzoxazole conjugated Schiff bases.

PubMed

Santos, Fabiano S; Costa, Tania M H; Stefani, Valter; Gonçalves, Paulo F B; Descalzo, Rodrigo R; Benvenutti, Edilson V; Rodembusch, Fabiano S

2011-11-24

Two Schiff bases were synthesized by reaction of 2-(4'-aminophenyl)benzoxazole derivatives with 4-N,N-diethylaminobenzaldehyde. UV-visible (UV-vis) and steady-state fluorescence in solution were applied in order to characterize its photophysical behavior. The Schiff bases present absorption in the UV region with fluorescence emission in the blue-green region, with a large Stokes' shift. The UV-vis data indicates that each dye behaves as two different chromophores in solution in the ground state. The fluorescence emission spectra of the dye 5a show that an intramolecular proton transfer (ESIPT) mechanism takes place in the excited state, whereas a twisted internal charge transfer (TICT) state is observed for the dye 5b. Theoretical calculations were performed in order to study the conformation and polarity of the molecules at their ground and excited electronic states. Using density functional theory (DFT) methods at theoretical levels BLYP/Aug-SV(P) for geometry optimizations and B3LYP/6-311++G(2d,p) for single-point energy evaluations, the calculations indicate that the lowest energy conformations are in all cases nonplanar and that the dipole moments of the excited state relaxed structures are much larger than those of the ground state structures, which corroborates the experimental UV-vis absorption results.

FTIR Studies of Internal Water Molecules of Bacteriorhodopsin: Structural Analysis of Halide-bound D85S and D212N Mutants in the Schiff Base Region

NASA Astrophysics Data System (ADS)

Shibata, Mikihiro; Kandori, Hideki

2007-12-01

Bacteriorhodopsin (BR), a membrane protein found in Halobacterium salinarum, functions as a light-driven proton pump. The Schiff base region has a quadropolar structure with positive charges located at the protonated Schiff base and Arg82, and counterbalancing negative charges located at Asp85 and Asp212 (Figure 1A). It is known that BR lacks a proton-pumping activity if Asp85 or Asp212 is neutralized by mutation. On the other hand, binding of C1- brings different effects for pumping functions in mutants at D85 and D212 position. While C1--bound D85T and D85S pump C1-, photovoltage measurements suggested that C1--bound D212N pumps protons at low pH. In this study, we measured low-temperature FTIR spectra of D85S and D212N containing various halides to compare the halide binding site of both proteins. In the case of D85S, the N-D stretching vibrations of the Schiff base were halide-dependent. This result suggests that the halide is a hydrogen-bond acceptor of the Schiff base, being consistent with the X-ray crystal structure. On the other hand, no halide dependence was observed for vibrational bands of the retinal skeleton and the Schiff base in the D212N mutant. This result suggests that the halide does not form a hydrogen bond with the Schiff base directly, unlike the mutation at D85 position. Halide-dependent water bands in the Schiff base region also differ between D85S and D212N. From these results, halide binding site of both proteins and role of two negative charges in BR will be discussed.

Antiaflatoxigenic and Antimicrobial Activities of Schiff Bases of 2-Hydroxy-4-methoxybenzaldehyde, Cinnamaldehyde, and Similar Aldehydes.

PubMed

Harohally, Nanishankar V; Cherita, Chris; Bhatt, Praveena; Anu Appaiah, K A

2017-10-11

2-Hydroxy-4-methoxybenzaldehyde (HMBA) is a nontoxic phenolic flavor from dietary source Decalipus hamiltonii and Hemidesmus indicus. HMBA is an excellent antimicrobial agent with additional antiaflatoxigenic potency. On the other hand, cinnamaldehyde from cinnamon is a widely employed flavor with significant antiaflatoxigenic activity. We have attempted the enhancement of antiaflatoxigenic and antimicrobial properties of HMBA, cinnamaldehyde, and similar molecules via Schiff base formation accomplished from condensation reaction with amino sugar (d-glucamine). HMBA derived Schiff bases exhibited commendable antiaflatoxigenic activity at the concentration 0.1 mg/mL resulting in 9.6 ± 1.9% growth of Aspergillus flavus and subsequent 91.4 ± 3.9% reduction of aflatoxin B 1 with respect to control.

A novel Schiff-base as a Cu(II) ion fluorescent sensor in aqueous solution

NASA Astrophysics Data System (ADS)

Gündüz, Z. Yurtman; Gündüz, C.; Özpınar, C.; Urucu, O. Aydın

2015-02-01

A new fluorescent Cu(II) sensor (L) obtained from the Schiff base of 5,5‧-methylene-bis-salicylaldehyde with amidol (2,4-diaminophenol) was synthesized and characterized by FT-IR, MS, 1H NMR, 13C NMR techniques. In the presence of pH 6.5 (KHPO4-Na2HPO4) buffer solutions, copper reacted with L to form a stable 2:1 complex. Fluorescence spectroscopic study showed that Schiff base is highly sensitive towards Cu(II) over other metal ions (K+, Na+, Al3+, Ni2+, Co2+, Fe3+, Zn2+, Pb2+) in DMSO/H2O (30%, v/v). The sensor L was successfully applied to the determination of copper in standard reference material. The structural properties and molecular orbitals of the complex formed between L and Cu2+ ions were also investigated using quantum chemical computations.

Step-Scan T-Cell Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) for Monitoring Environmental Air Pollutants

NASA Astrophysics Data System (ADS)

Liu, Lixian; Mandelis, Andreas; Melnikov, Alexander; Michaelian, Kirk; Huan, Huiting; Haisch, Christoph

2016-07-01

Air pollutants have adverse effects on the Earth's climate system. There is an urgent need for cost-effective devices capable of recognizing and detecting various ambient pollutants. An FTIR photoacoustic spectroscopy (FTIR-PAS) method based on a commercial FTIR spectrometer developed for air contamination monitoring will be presented. A resonant T-cell was determined to be the most appropriate resonator in view of the low-frequency requirement and space limitations in the sample compartment. Step-scan FTIR-PAS theory for regular cylinder resonator has been described as a reference for prediction of T-cell vibration principles. Both simulated amplitude and phase responses of the T-cell show good agreement with measurement data Carbon dioxide IR absorption spectra were used to demonstrate the capacity of the FTIR-PAS method to detect ambient pollutants. The theoretical detection limit for carbon dioxide was found to be 4 ppmv. A linear response to carbon dioxide concentration was found in the range from 2500 ppmv to 5000 ppmv. The results indicate that it is possible to use step-scan FTIR-PAS with a T-cell as a quantitative method for analysis of ambient contaminants.

Toxins vapC and pasB from prokaryotic TA modules remain active in mammalian cancer cells.

PubMed

Wieteska, Łukasz; Skulimowski, Aleksander; Cybula, Magdalena; Szemraj, Janusz

2014-09-30

Among the great number of addictive modules which have been discovered, only a few have been characterized. However, research concerning the adoption of toxins from these systems shows their great potential as a tool for molecular biology and medicine. In our study, we tested two different toxins derived from class II addictive modules, pasAB from plasmid pTF-FC2 (Thiobacillus ferrooxidans) and vapBC 2829Rv (Mycobacterium tuberculosis), in terms of their usefulness as growth inhibitors of human cancer cell lines, namely KYSE 30, MCF-7 and HCT 116. Transfection of the pasB and vapC genes into the cells was conducted with the use of two different expression systems. Cellular effects, such as apoptosis, necrosis and changes in the cell cycle, were tested by applying flow cytometry with immunofluorescence staining. Our findings demonstrated that toxins VapC and PasB demonstrate proapoptotic activity in the human cancer cells, regardless of the expression system used. As for the toxin PasB, observed changes were more subtle than for the VapC. The level of expression for both the genes was monitored by QPCR and did not reveal statistically significant differences within the same cell line.

FNAC Aided Diagnosis and Categorization of Hepatoblastoma:: A Report of Three Cases.

PubMed

Bera, Goutam; Das, Ram Narayan; Islam, Nelofar; Roy, Paromita; Mishra, Prafulla Kumar; Datta, Chhanda; Chaudhuri, Manoj Kumar; Chatterjee, Uttara

2017-01-01

Hepatoblastoma is the most common primary malignant hepatic tumour of infancy and early childhood. Histologically hepatoblastomas are categorized into pure epithelial and mixed epithelial-mesenchymal types and epithelial type is further subcategorized into pure fetal type, fetal and embryonal type, pure embryonal, and small cell types. This categorization has been shown to have prognostic and therapeutic implication. Fine needle aspiration cytology (FNAC) is useful in pre-operative diagnosis and categorization in most cases of hepatoblastomas. Periodic acid-Schiff (PAS) stain can be helpful to differentiate fetal subtype from embryonal subtype of hepatoblastoma. Here we describe three cases of hepatoblastomas diagnosed and categorized on cytology with subsequent confirmation on histological examination. Diagn. Cytopathol. 2017;45:77-82. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

An analysis of characteristics of post-authorisation studies registered on the ENCePP EU PAS Register

PubMed Central

Carroll, Robert; Ramagopalan, Sreeram V.; Cid-Ruzafa, Javier; Lambrelli, Dimitra; McDonald, Laura

2017-01-01

Background: The objective of this study was to investigate the study design characteristics of Post-Authorisation Studies (PAS) requested by the European Medicines Agency which were recorded on the European Union (EU) PAS Register held by the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (ENCePP). Methods: We undertook a cross-sectional descriptive analysis of all studies registered on the EU PAS Register as of 18 th October 2016. Results: We identified a total of 314 studies on the EU PAS Register, including 81 (26%) finalised, 160 (51%) ongoing and 73 (23%) planned. Of those studies identified, 205 (65%) included risk assessment in their scope, 133 (42%) included drug utilisation and 94 (30%) included effectiveness evaluation. Just over half of the studies (175; 56%) used primary data capture, 135 (43%) used secondary data and 4 (1%) used a hybrid design combining both approaches. Risk assessment and effectiveness studies were more likely to use primary data capture (60% and 85% respectively as compared to 39% and 14% respectively for secondary). The converse was true for drug utilisation studies where 59% were secondary vs. 39% for primary. For type 2 diabetes mellitus, database studies were more commonly used (80% vs 3% chart review, 3% hybrid and 13% primary data capture study designs) whereas for studies in oncology, primary data capture were more likely to be used (85% vs 4% chart review, and 11% database study designs). Conclusions: Results of this analysis show that PAS design varies according to study objectives and therapeutic area. PMID:29188016

Syntheses, spectroscopic characterization, SOD-like properties and antibacterial activities of dimer copper (II) and nickel (II) complexes based on imine ligands containing 2-aminothiophenol moiety: X-ray crystal structure determination of disulfide Schiff bases

NASA Astrophysics Data System (ADS)

Bharti, Sulakshna; Choudhary, Mukesh; Mohan, Bharti; Rawat, S. P.; Sharma, S. R.; Ahmad, K.

2018-07-01

A series of new dimer complexes of copper (II) and nickel (II) were designed and synthesized using the Schiff base ligands which was formed by the condensation of 2-aminothiophenol with 2- methoxybenzaldehyde, 3-formylbenzonitrile and 3-bromo-2-hydroxy-5-nitrobenzaldehyde, respectively. The synthesized metallic complexes were characterized by using different physicochemical and spectroscopic methods. The most plausible geometry for the 1:2 complexes appeared to be distorted square-planar or tetrahedral environments. All the synthesized metal complexes are found to be binuclear and confirmed by elemental analyses, magnetic susceptibility measurements and ESR spectroscopy. The Schiff base ligands (HL1/HL2/H2L) were coordinated to the metal ions through the ONS/SNN and/or N, S donor atoms. In order to prevent the oxidation of the thiol group during the formation of Schiff bases and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structures of the Schiff base ligands showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff bases as a new double Schiff base ligands (L1a/L2a/H2La). The L1b ligand is a bicyclic ring system of N, S-containing heterocyclic. The crystal structures of the double Schiff bases were determined by single crystal X-ray diffraction. The molar conductivity values of the complexes in DMSO implied the presence of non-electrolyte species. The SOD-like activity of Schiff bases and its complexes were investigated by NBT-DMSO assay and IC50 values were evaluated. Their biological properties have also been studied. These complexes were also tested for their in vitro antibacterial screening activities against three bacteria (Streptococcus aureus, Salmonella typhi, and Escherichia coli) comparing with the Schiff base ligands. Most of the complexes have higher antibacterial activities than those of the free Schiff bases, double Schiff bases and the control.

Supplementation with L-glutamine prevents tumor growth and cancer-induced cachexia as well as restores cell proliferation of intestinal mucosa of Walker-256 tumor-bearing rats.

PubMed

Martins, Heber Amilcar; Sehaber, Camila Caviquioli; Hermes-Uliana, Catchia; Mariani, Fernando Augusto; Guarnier, Flavia Alessandra; Vicentini, Geraldo Emílio; Bossolani, Gleison Daion Piovezana; Jussani, Laraine Almeida; Lima, Mariana Machado; Bazotte, Roberto Barbosa; Zanoni, Jacqueline Nelisis

2016-12-01

This study aimed to evaluate the intestinal mucosa of the duodenum and jejunum of Walker-256 tumor-bearing rats supplemented with L-glutamine. Thirty-two male 50-day-old Wistar rats (Rattus norvegicus) were randomly divided into four groups: control (C), control supplemented with 2 % L-glutamine (GC), Walker-256 tumor (WT), and Walker-256 tumor supplemented with 2 % L-glutamine (TWG). Walker-256 tumor was induced by inoculation viable tumor cells in the right rear flank. After 10 days, celiotomy was performed and duodenal and jejunal tissues were removed and processed. We evaluated the cachexia index, proliferation index, villus height, crypt depth, total height of the intestinal wall, and number of goblet cells by the technique of periodic acid-Schiff (PAS). Induction of Walker-256 tumor promoted a reduction of metaphase index in the TW group animals, which was accompanied by a reduction in the villous height and crypt depths, resulting in atrophy of the intestinal wall as well as increased PAS-positive goblet cells. Supplementation with L-glutamine reduced the tumor growth and inhibited the development of the cachectic syndrome in animals of the TWG group. Furthermore, amino acid supplementation promoted beneficial effects on the intestinal mucosa in the TWG animals through restoration of the number of PAS-positive goblet cells. Therefore, supplementation with 2 % L-glutamine exhibited a promising role in the prevention of tumor growth and cancer-associated cachexia as well as restoring the intestinal mucosa in the duodenum and jejunum of Walker-256 tumor-bearing rats.

Syntheses, crystal structures, anticancer activities of three reduce Schiff base ligand based transition metal complexes

NASA Astrophysics Data System (ADS)

Chang, Hui-Qin; Jia, Lei; Xu, Jun; Zhu, Tao-Feng; Xu, Zhou-Qing; Chen, Ru-Hua; Ma, Tie-Liang; Wang, Yuan; Wu, Wei-Na

2016-02-01

Three nickel(II) complexes, [Ni2(L1)2(tren)2(H2O)](ClO4)3 (1), [NiL2(tren)2](ClO4)·2.5H2O (2), [NiL2(tren)2]I·1.5H2O·CH3OH (3) based on amino acid reduced Schiff ligands are synthesized and characterized by physico-chemical and spectroscopic methods. The results show that in all complexes, the amino acid ligand is deprotonated and acts as an anionic ligand. In the dinuclear complex 1, each Ni(II) atom has a distorted octahedron geometry while with different coordination environment. However, the complexes 2 and 3 are mononuclear, almost with the same coordination environment. Furthermore, in vitro experiments are carried out, including MTT assay, Annexin V/PI flow cytometry and western blotting, to assess whether the complexes have antitumor effect. And the results show that all the three complexes have moderate anticancer activity towards human hepatic cancer (HepG2), human cervical cancer (HeLa) and human prostate (PC3) cell lines, in a concentration dependent way. The complex 1 exhibit higher cytotoxicity than the other two complexes and can induce human hepatic cancer cell (HepG2) to cell apoptosis by activating caspase 3.

Uric acid causes kidney injury through inducing fibroblast expansion, Endothelin-1 expression, and inflammation.

PubMed

Romi, Muhammad Mansyur; Arfian, Nur; Tranggono, Untung; Setyaningsih, Wiwit Ananda Wahyu; Sari, Dwi Cahyani Ratna

2017-10-31

Uric acid (UA) plays important roles in inducing renal inflammation, intra-renal vasoconstriction and renal damage. Endothelin-1 (ET-1) is a well-known profibrotic factor in the kidney and is associated with fibroblast expansion. We examined the role of hyperuricemia conditions in causing elevation of ET-1 expression and kidney injury. Hyperuricemia was induced in mice using daily intraperitoneal injection of uric acid 125 mg/Kg body weight. An NaCl injection was used in control mice. Mice were euthanized on days-7 (UA7) and 14 (UA14). We also added allopurinol groups (UAL7 and UAL14) with supplementation of allopurinol 50 mg/Kg body weight orally. Uric acid and creatinine serum were measured from blood serum. Periodic Acid Schiff (PAS) and Sirius Red staining were done for glomerulosclerosis, tubular injury and fibrosis quantification. mRNA expression examination was performed for nephrin, podocin, preproEndothelin-1 (ppET-1), MCP-1 and ICAM-1. PDGFRβ immunostaining was done for quantification of fibroblast, while α-SMA immunostaining was done for localizing myofibroblast. Western blot analysis was conducted to quantify TGF-β1, α-SMA and Endothelin A Receptor (ETAR) protein expression. Uric acid and creatinine levels were elevated after 7 and 14 days and followed by significant increase of glomerulosclerosis and tubular injury score in the uric acid group (p < 0.05 vs. control). Both UA7 and UA14 groups had higher fibrosis, tubular injury and glomerulosclerosis with significant increase of fibroblast cell number compared with control. RT-PCR revealed down-regulation of nephrin and podocin expression (p < 0.05 vs. control), and up-regulation of MCP-1, ET-1 and ICAM-1 expression (p < 0.05 vs. control). Western blot revealed higher expression of TGF-β1 and α-SMA protein expression. Determination of allopurinol attenuated kidney injury was based on reduction of fibroblast cell number, inflammation mediators and ppET-1 expression with reduction of TGF

Synthesis, characterization and biological properties of thienyl derived triazole Schiff bases and their oxovanadium(IV) complexes.

PubMed

Chohan, Zahid H; Sumrra, Sajjad H

2012-04-01

A new series of biologically active thienyl derived triazole Schiff bases and their oxovanadium(IV) complexes have been synthesized and characterized on the basis of physical (m.p., magnetic susceptibility and conductivity), spectral (IR, ¹H and ¹³C NMR, electronic and mass spectrometry) and microanalytical data. All the Schiff base ligands and their oxovanadium(IV) complexes have been subjected to in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella enterica serover typhi) and two Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains and, for in vitro antifungal activity against Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani and Candida glabrata. Brine shrimp bioassay was also carried out to check the cytotoxic nature of these compounds.

Pheromone traps and other methods in assessing pine beauty moth (Panolis flammea Schiff.)

Treesearch

Algimantas Ziogas

2003-01-01

The objective of this research was to evaluate different methodologies for quantifying pine beauty moth (Panolis flammea Schiff.) populations in pine stands of Southern part of Lithuania. Evaluations were conducted in selected pine stands by assessing the following: pupae (in the litter); larvae (falling from trees after chemical knock down); and...

Hematology, morphology, cytochemical staining, and ultrastuctural characteristics of blood cells in king cobras (Ophiophagus hannah).

PubMed

Salakij, Chaleow; Salakij, Jarernsak; Apibal, Suntaree; Narkkong, Nual-Anong; Chanhome, Lawan; Rochanapat, Nirachara

2002-01-01

King cobras (Ophiophagus hannah) have been captive-bred at Queen Saovabha Memorial Institute since 1996 to supply venom for antivenom production. Hematologic tests would be useful for evaluating the health of the snakes, however, basic hematologic data and morphology have not been described for this species. The purpose of this study was to determine basic hematologic values and evaluate light microscopic, cytochemical, and electron microscopic characteristics of king cobra blood cells. Blood samples from 13 wild-caught and 15 captive-bred king cobras were collected into EDTA from the ventral caudal vein. A CBC was done using standard methods. Significant differences between groups were determined using t-tests. Cytochemical stains (periodic acid-Schiff [PAS], Sudan black B [SBB], alpha-naphthyl acetate esterase [ANAE], acid phosphatase [AcP], and beta-glucuronidase [beta-glu]), and scanning and transmission electron microscopy were done using standard techniques. Eighteen snakes (64.3%) were positive for Hepatozoon infection. Hepatozoon organisms were detected nearly twice as frequently in wild-caught (11/13) as in captive-bred (7/15) snakes. Total WBC, azurophil, and lymphocyte counts were higher and fibrinogen concentration was lower in Hepatozoon-positive snakes. Captive-bred snakes had higher RBC values, lower azurophil, heterophil, and punctate reticulocyte percentages, and higher lymphocyte numbers compared with wild-caught snakes. Lymphocytes were the most commonly observed WBCs, and stained positive with PAS, ANAE, AcP, and beta-glu. Azurophil granules stained positive with SBB, PAS, and ANAE. Heterophils were the largest WBCs; their granules stained with SBB, ANAE, and beta-glu. Basophil granules stained with PAS, SBB, ANAE, and beta-glu. Thrombocytes were strongly positive with PAS. Transmission electron microscopic examination revealed organelles within all WBCs except eosinophils and revealed the gamonts of Hepatozoon sp in RBCs and azurophils. These

Recruitment of single muscle fibers during submaximal cycling exercise.

PubMed

Altenburg, T M; Degens, H; van Mechelen, W; Sargeant, A J; de Haan, A

2007-11-01

In literature, an inconsistency exists in the submaximal exercise intensity at which type II fibers are activated. In the present study, the recruitment of type I and II fibers was investigated from the very beginning and throughout a 45-min cycle exercise at 75% of the maximal oxygen uptake, which corresponded to 38% of the maximal dynamic muscle force. Biopsies of the vastus lateralis muscle were taken from six subjects at rest and during the exercise, two at each time point. From the first biopsy single fibers were isolated and characterized as type I and II, and phosphocreatine-to-creatine (PCr/Cr) ratios and periodic acid-Schiff (PAS) stain intensities were measured. Cross sections were cut from the second biopsy, individual fibers were characterized as type I and II, and PAS stain intensities were measured. A decline in PCr/Cr ratio and in PAS stain intensity was used as indication of fiber recruitment. Within 1 min of exercise both type I and, although to a lesser extent, type II fibers were recruited. Furthermore, the PCr/Cr ratio revealed that the same proportion of fibers was recruited during the whole 45 min of exercise, indicating a rather constant recruitment. The PAS staining, however, proved inadequate to fully demonstrate fiber recruitment even after 45 min of exercise. We conclude that during cycling exercise a greater proportion of type II fibers is recruited than previously reported for isometric contractions, probably because of the dynamic character of the exercise. Furthermore, the PCr/Cr ratio method is more sensitive in determining fiber activation than the PAS stain intensity method.

Schiff bases of putrescine with methylglyoxal protect from cellular damage caused by accumulation of methylglyoxal and reactive oxygen species in Dictyostelium discoideum.

PubMed

Park, Seong-Jun; Kwak, Min-Kyu; Kang, Sa-Ouk

2017-05-01

Polyamines protect protein glycation in cells against the advanced glycation end product precursor methylglyoxal, which is inevitably produced during glycolysis, and the enzymes that detoxify this α-ketoaldehyde have been widely studied. Nonetheless, nonenzymatic methylglyoxal-scavenging molecules have not been sufficiently studied either in vitro or in vivo. Here, we hypothesized reciprocal regulation between polyamines and methylglyoxal modeled in Dictyostelium grown in a high-glucose medium. We based our hypothesis on the reaction between putrescine and methylglyoxal in putrescine-deficient (odc - ) or putrescine-overexpressing (odc oe ) cells. In these strains, growth and cell cycle were found to be dependent on cellular methylglyoxal and putrescine contents. The odc - cells showed growth defects and underwent G1 phase cell cycle arrest, which was efficiently reversed by exogenous putrescine. Cellular methylglyoxal, reactive oxygen species (ROS), and glutathione levels were remarkably changed in odc oe cells and odc̄ cells. These results revealed that putrescine may act as an intracellular scavenger of methylglyoxal and ROS. Herein, we observed interactions of putrescine and methylglyoxal via formation of a Schiff base complex, by UV-vis spectroscopy, and confirmed this adduct by liquid chromatography with mass spectrometry via electrospray ionization. Schiff bases were isolated, analyzed, and predicted to have molecular masses ranging from 124 to 130. We showed that cellular putrescine-methylglyoxal Schiff bases were downregulated in proportion to the levels of endogenous or exogenous putrescine and glutathione in the odc mutants. The putrescine-methylglyoxal Schiff base affected endogenous metabolite levels. This is the first report showing that cellular methylglyoxal functions as a signaling molecule through reciprocal interactions with polyamines by forming Schiff bases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis, crystal structure, fluorescence and electrochemical studies of a new tridentate Schiff base ligand and its nickel(II) and palladium(II) complexes

NASA Astrophysics Data System (ADS)

Shafaatian, Bita; Soleymanpour, Ahmad; Kholghi Oskouei, Nasim; Notash, Behrouz; Rezvani, Seyyed Ahmad

2014-07-01

A new unsymmetrical tridentate Schiff base ligand was derived from the 1:1 M condensation of ortho-vanillin with 2-mercaptoethylamine. Nickel and palladium complexes were obtained by the reaction of the tridentate Schiff base ligand with nickel(II) acetate tetrahydrate and palladium(II) acetate in 2:1 M ratio. In nickel and palladium complexes the ligand was coordinated to metals via the imine N and enolic O atoms. The S groups of Schiff bases were not coordinated to the metals and S-S coupling was occured. The complexes have been found to possess 1:2 Metal:Ligand stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The complexes exhibited octahedral coordination geometry. The emission spectra of the ligand and its complexes were studied in methanol. Electrochemical properties of the ligand and its metal complexes were investigated in the CH3CN solvent at the 100 mV s-1 scan rate. The ligand and metal complexes showed both reversible and quasi-reversible processes at this scan rate. The Schiff base and its complexes have been characterized by IR, 1H NMR, UV/Vis, elemental analyses and conductometry. The crystal structure of nickel complex has been determined by single crystal X-ray diffraction.

Ion Sensor Properties of Fluorescent Schiff Bases Carrying Dipicolylamine Groups. A Simple Spectrofluorimetric Method to Determine Cu (II) in Water Samples.

PubMed

Vanlı, Elvan; Mısır, Miraç Nedim; Alp, Hakan; Ak, Tuğba; Özbek, Nurhayat; Ocak, Ümmühan; Ocak, Miraç

2017-09-01

Four fluorescent Schiff bases carrying dipicolylamine groups were designed and synthesized to determine their ion sensor properties in partial aqueous solution. The corresponding amine compound and the aldehyde compounds such as 1-naphthaldehyde, 9-anthraldehyde, phenanthrene-9-carboxaldehyde and 1-pyrenecarboxaldehyde were used to prepare the new Schiff bases. The influence of many metal cations and anions on the spectroscopic properties of the ligands was investigated in ethanol-water (1:1) by means of emission spectrometry. From the spectrofluorimetric titrations, the complexation stoichiometry and complex stability constants of the ligands with Cd 2+ , Zn 2+ , Cu 2+ and Hg 2+ ions were determined. The ligands did not interact with the anions. However, the Schiff base derived from phenanthrene-9-carboxaldehyde showed sensitivity for Cu 2+ among the tested metal ions. The phenanthrene-based Schiff base was used as analytical ligand for the simple and fast determination of Cu 2+ ion in water samples. A modified standard addition method was used to eliminate matrix effect. The linear range was from 0.3 mg/L to 3.8 μg/L. Detection and quantification limits were 0.14 and 0.43 mg/L, respectively. Maximum contaminant level goal (MCLG) for copper in drinking water according to EPA is 1.3 mg/L. The proposed method has high sensitivity to determine copper in drinking waters.

Kinetics and thermodynamics of irreversible inhibition of matrix metalloproteinase 2 by a Co(III) Schiff base complex

PubMed Central

Harney, Allison S.; Sole, Laura B.

2012-01-01

Cobalt(III) Schiff base complexes have been used as potent inhibitors of protein function through the coordination to histidine residues essential for activity. The kinetics and thermodynamics of the binding mechanism of Co(acacen)(NH3)2Cl [Co(acacen); where H2acacen is bis(acetylacetone)ethylenediimine] enzyme inhibition has been examined through the inactivation of matrix metalloproteinase 2 (MMP-2) protease activity. Co(acacen) is an irreversible inhibitor that exhibits time- and concentration-dependent inactivation of MMP-2. Co(acacen) inhibition of MMP-2 is temperature-dependent, with the inactivation increasing with temperature. Examination of the formation of the transition state for the MMP-2/Co(acacen) complex was determined to have a positive entropy component indicative of greater disorder in the MMP-2/Co(acacen) complex than in the reactants. With further insight into the mechanism of Co(acacen) complexes, Co(III) Schiff base complex protein inactivators can be designed to include features regulating activity and protein specificity. This approach is widely applicable to protein targets that have been identified to have clinical significance, including matrix metalloproteinases. The mechanistic information elucidated here further emphasizes the versatility and utility of Co(III) Schiff base complexes as customizable protein inhibitors. PMID:22729838

Experimental study on spatio-temporal behavior of a single particle forming a particle accumulation structure (PAS) in half-zone liquid bridge

NASA Astrophysics Data System (ADS)

Oba, Takeru; Ueno, Ichiro; Kaneko, Toshihiro

2017-11-01

We focus on particle behavior due to thermocapillary-driven convection in a half-zone liquid bridge of high-Prandtl number fluid. It has been known that the suspended particles exhibit a unique solid-like structure known as 'particle accumulation structure (PAS)' in a rotating frame of reference with traveling-type hydrothermal wave. It is said that PAS is caused by interaction between particles and the free surface of a half-zone liquid bridge. Such structures arise even under small Stokes number conditions. When observing PAS two-dimensionally, it looks like a closed single string, but the actual movement of particles is different. Therefore we employ three-dimensional particle tracking velocimetry to the half-zone liquid bridge of 2.5 mm in radius and 1.7 mm in height, and detect the particle behaviors close to the free surface. We explain the spatio-temporal correlation between the solid-like global structure of PAS and the local particle motions, and make comparisons with proposed physical models of PAS formation.

Evaluation of the Alphasense Optical Particle Counter (OPC-N2) and the Grimm Portable Aerosol Spectrometer (PAS-1.108)

PubMed Central

Sousan, Sinan; Koehler, Kirsten; Hallett, Laura; Peters, Thomas M.

2017-01-01

We compared the performance of a low-cost (∼$500), compact optical particle counter (OPC, OPC-N2, Alphasense) to another OPC (PAS-1.108, Grimm Technologies) and reference instruments. We measured the detection efficiency of the OPCs by size from 0.5 to 5 μm for monodispersed, polystyrene latex (PSL) spheres. We then compared number and mass concentrations measured with the OPCs to those measured with reference instruments for three aerosols: salt, welding fume and Arizona road dust. The OPC-N2 detection efficiency for monodispersed was similar to the PAS-1.108 for particles larger than 0.8 μm (minimum of 79% at 1 μm and maximum of 101% at 3 μm). For 0.5-μm particles, the detection efficiency of OPCN2 was underestimated at 78%, whereas PAS-1.108 overestimated concentrations by 183%. The mass concentrations from the OPCs were linear (r ≥ 0.97) with those from the reference instruments for all aerosols, although the slope and intercept were different. The mass concentrations were overestimated for dust (OPC-N2, slope = 1.6; PAS-1.108, slope = 2.7) and underestimated for welding fume (OPC-N2, slope = 0.05; PAS-1.108, slope = 0.4). The coefficient of variation (CV, precision) for OPC-N2 for all experiments was between 4.2% and 16%. These findings suggest that, given site-specific calibrations, the OPC-N2 can provide number and mass concentrations similar to the PAS-1.108 for particles larger than 1 μm. PMID:28871213

Evaluation of the Alphasense Optical Particle Counter (OPC-N2) and the Grimm Portable Aerosol Spectrometer (PAS-1.108).

PubMed

Sousan, Sinan; Koehler, Kirsten; Hallett, Laura; Peters, Thomas M

2016-01-01

We compared the performance of a low-cost (∼$500), compact optical particle counter (OPC, OPC-N2, Alphasense) to another OPC (PAS-1.108, Grimm Technologies) and reference instruments. We measured the detection efficiency of the OPCs by size from 0.5 to 5 μm for monodispersed, polystyrene latex (PSL) spheres. We then compared number and mass concentrations measured with the OPCs to those measured with reference instruments for three aerosols: salt, welding fume and Arizona road dust. The OPC-N2 detection efficiency for monodispersed was similar to the PAS-1.108 for particles larger than 0.8 μm (minimum of 79% at 1 μm and maximum of 101% at 3 μm). For 0.5-μm particles, the detection efficiency of OPCN2 was underestimated at 78%, whereas PAS-1.108 overestimated concentrations by 183%. The mass concentrations from the OPCs were linear (r ≥ 0.97) with those from the reference instruments for all aerosols, although the slope and intercept were different. The mass concentrations were overestimated for dust (OPC-N2, slope = 1.6; PAS-1.108, slope = 2.7) and underestimated for welding fume (OPC-N2, slope = 0.05; PAS-1.108, slope = 0.4). The coefficient of variation (CV, precision) for OPC-N2 for all experiments was between 4.2% and 16%. These findings suggest that, given site-specific calibrations, the OPC-N2 can provide number and mass concentrations similar to the PAS-1.108 for particles larger than 1 μm.

Challenges to "Classic" Esophageal Candidiasis: Looks Are Usually Deceiving.

PubMed

Alsomali, Mohammed I; Arnold, Michael A; Frankel, Wendy L; Graham, Rondell P; Hart, Phil A; Lam-Himlin, Dora M; Naini, Bita V; Voltaggio, Lysandra; Arnold, Christina A

2017-01-01

We undertook the first case control study of histologically confirmed esophageal candidiasis (EC). A computer search from July 2012 through February 2015 identified 1,011 esophageal specimens, including 40 cases of EC and 20 controls. The EC incidence was 5.2%; it was associated with immunosuppression and endoscopic white plaques and breaks. Smoking was a predisposing factor, and alcohol was protective. EC had no unique symptoms, and 54% of endoscopic reports did not suspect EC. Important histologic clues included superficial and detached fragments of desquamated and hyper-pink parakeratosis, acute inflammation, intraepithelial lymphocytosis, dead keratinocytes, and bacterial overgrowth. Thirty percent had no neutrophilic infiltrate. Pseudohyphae were seen on H&E in 92.5% (n = 37/40). "Upfront" periodic acid-Schiff with diastase (PAS/D) on all esophageal specimens would have generated $68,333.49 in patient charges. Our targeted PAS/D strategy resulted in $13,044.87 in patient charges (cost saving = 80.9%, $55,288.62). We describe the typical morphology of EC and recommend limiting PAS/D to cases where the organisms are not readily identifiable on H&E and with at least one of the following: (1) ulcer, (2) suspicious morphology, and/or (3) clinical impression of EC. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Immunohistochemical Expression of Placental Alkaline Phosphatase in Five Cases of Seminoma in Rabbits.

PubMed

Banco, B; Ferreira da Silva, J; Cotti Cometti, S; Stefanello, D; Grieco, V

2017-05-01

Testicular seminoma is reported in the rabbit but data about the immunophenotype of these tumours are lacking. The classification of human testicular germ cell tumours includes spermatocytic tumour (ST) originating from the post-pubertal spermatogonia/spermatocytes, which metastasizes rarely, and seminoma (SE), originating from gonocytes, which is malignant and metastasizes frequently. Gonocytes express placental alkaline phosphatase (PLAP) and are stained with periodic acid-Schiff (PAS). We report five cases of seminoma in pet rabbits. Microscopically, all the cases were diffuse seminoma and in one case there was metastasis to a sublumbar lymph node. Immunohistochemical expression of PLAP was diffuse in this metastatic tumour, in two other cases it was multifocal, in another it was limited to rare cells and in the remaining case was negative. PAS-positive cells were detected only in the four cases that expressed PLAP. These four cases were therefore classified as SE and the tumour without PLAP labelling or PAS staining was defined as ST. Both forms of human germ cell tumour therefore occur in the rabbit. SE appears to be well represented and may show metastasis, paralleling the human counterpart. The results of this study provide a basis for further evaluations of the rabbit as a possible animal model for the study of human SE. Copyright © 2017 Elsevier Ltd. All rights reserved.

Crystal structure of the Alpha subunit PAS domain from soluble guanylyl cyclase

PubMed Central

Purohit, Rahul; Weichsel, Andrzej; Montfort, William R

2013-01-01

Soluble guanylate cyclase (sGC) is a heterodimeric heme protein of ∼150 kDa and the primary nitric oxide receptor. Binding of NO stimulates cyclase activity, leading to regulation of cardiovascular physiology and providing attractive opportunities for drug discovery. How sGC is stimulated and where candidate drugs bind remains unknown. The α and β sGC chains are each composed of Heme-Nitric Oxide Oxygen (H-NOX), Per-ARNT-Sim (PAS), coiled-coil and cyclase domains. Here, we present the crystal structure of the α1 PAS domain to 1.8 Å resolution. The structure reveals the binding surfaces of importance to heterodimer function, particularly with respect to regulating NO binding to heme in the β1 H-NOX domain. It also reveals a small internal cavity that may serve to bind ligands or participate in signal transduction. PMID:23934793

Role of the Cytoplasmic N-terminal Cap and Per-Arnt-Sim (PAS) Domain in Trafficking and Stabilization of Kv11.1 Channels*

PubMed Central

Ke, Ying; Hunter, Mark J.; Ng, Chai Ann; Perry, Matthew D.; Vandenberg, Jamie I.

2014-01-01

The N-terminal cytoplasmic region of the Kv11.1a potassium channel contains a Per-Arnt-Sim (PAS) domain that is essential for the unique slow deactivation gating kinetics of the channel. The PAS domain has also been implicated in the assembly and stabilization of the assembled tetrameric channel, with many clinical mutants in the PAS domain resulting in reduced stability of the domain and reduced trafficking. Here, we use quantitative Western blotting to show that the PAS domain is not required for normal channel trafficking nor for subunit-subunit interactions, and it is not necessary for stabilizing assembled channels. However, when the PAS domain is present, the N-Cap amphipathic helix must also be present for channels to traffic to the cell membrane. Serine scan mutagenesis of the N-Cap amphipathic helix identified Leu-15, Ile-18, and Ile-19 as residues critical for the stabilization of full-length proteins when the PAS domain is present. Furthermore, mutant cycle analysis experiments support recent crystallography studies, indicating that the hydrophobic face of the N-Cap amphipathic helix interacts with a surface-exposed hydrophobic patch on the core of the PAS domain to stabilize the structure of this critical gating domain. Our data demonstrate that the N-Cap amphipathic helix is critical for channel stability and trafficking. PMID:24695734

Patency of Saphenous Vein Grafts Using the PAS-Port System During Coronary Artery Bypass Surgery.

PubMed

Kubota, Hiroshi; Endo, Hidehito; Ishii, Hikaru; Tsuchiya, Hiroshi; Takahashi, Yu; Inaba, Yusuke; Noma, Mio; Yoshimoto, Akihiro; Higuchi, Satoshi; Kohshoh, Hideyasu; Taniai, Seiichi; Ishiguro, Haruhisa; Yoshino, Hideaki; Sudo, Kenichi

2017-08-01

Several proximal anastomosis devices have been developed to shorten the time required for a proximal anastomosis and to avoid aortic cross-/side-clamping during coronary artery bypass grafting. This study retrospectively examined the patency of saphenous vein grafts (SVGs) using the PAS-Port System (Cardia Inc, Redwood City, CA). From 2004 to 2014, 451 patients underwent coronary artery bypass graft operations requiring at least 1 proximal anastomosis using a PAS-Port device. A total of 802 PAS-Port devices were used, and 95.0% (762 of 802) were implanted successfully. Among the successfully implanted anastomoses, 76.8% (585 of 762) were evaluated using coronary angiography or multidimensional computed tomography, or both. The evaluations were performed between postoperative days 4 and 3,182 (mean, 319 ± 624 days). The early (1 to 365 days) and the midterm to long-term (more than 366 days) occlusion rates were examined. A complete postoperative clinical course was recorded for 70.7% of the patients. Overall, 93.8% (549 of 585) of the device-dependent SVGs were patent. The patency rates of device-dependent SVGs that were 1, 2, 3, 4, 5, 6, 7, and 8 years old were 90.1% ± 1.8%, 87.1% ± 2.3%, 86.1% ± 2.5%, 82.9% ± 3.3%, 80.6% ± 3.9%, 77.2% ± 5.0%, 77.2% ± 5.0%, and 70.2% ± 8.1%, respectively. The longest follow-up period was 3,182 days (8.7 years). The occlusion rate for device-dependent SVGs tended to decrease as the number of patients accumulated. The PAS-Port system provided acceptable SVG patency and clinical outcome for the early and midterm to long-term. There may be a learning curve for the use of PAS-Port device that affects the device-dependent SVG patency. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

A comprehensive protein-protein interactome for yeast PAS kinase 1 reveals direct inhibition of respiration through the phosphorylation of Cbf1.

PubMed

DeMille, Desiree; Bikman, Benjamin T; Mathis, Andrew D; Prince, John T; Mackay, Jordan T; Sowa, Steven W; Hall, Tacie D; Grose, Julianne H

2014-07-15

Per-Arnt-Sim (PAS) kinase is a sensory protein kinase required for glucose homeostasis in yeast, mice, and humans, yet little is known about the molecular mechanisms of its function. Using both yeast two-hybrid and copurification approaches, we identified the protein-protein interactome for yeast PAS kinase 1 (Psk1), revealing 93 novel putative protein binding partners. Several of the Psk1 binding partners expand the role of PAS kinase in glucose homeostasis, including new pathways involved in mitochondrial metabolism. In addition, the interactome suggests novel roles for PAS kinase in cell growth (gene/protein expression, replication/cell division, and protein modification and degradation), vacuole function, and stress tolerance. In vitro kinase studies using a subset of 25 of these binding partners identified Mot3, Zds1, Utr1, and Cbf1 as substrates. Further evidence is provided for the in vivo phosphorylation of Cbf1 at T211/T212 and for the subsequent inhibition of respiration. This respiratory role of PAS kinase is consistent with the reported hypermetabolism of PAS kinase-deficient mice, identifying a possible molecular mechanism and solidifying the evolutionary importance of PAS kinase in the regulation of glucose homeostasis. © 2014 DeMille et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Faux-Pas Test: A Proposal of a Standardized Short Version.

PubMed

Fernández-Modamio, Mar; Arrieta-Rodríguez, Marta; Bengochea-Seco, Rosario; Santacoloma-Cabero, Iciar; Gómez de Tojeiro-Roce, Juan; García-Polavieja, Bárbara; González-Fraile, Eduardo; Martín-Carrasco, Manuel; Griffin, Kim; Gil-Sanz, David

2018-06-26

Previous research on theory of mind suggests that people with schizophrenia have difficulties with complex mentalization tasks that involve the integration of cognition and affective mental states. One of the tools most commonly used to assess theory of mind is the Faux-Pas Test. However, it presents two main methodological problems: 1) the lack of a standard scoring system; 2) the different versions are not comparable due to a lack of information on the stories used. These methodological problems make it difficult to draw conclusions about performance on this test by people with schizophrenia. The aim of this study was to develop a reduced version of the Faux-Pas test with adequate psychometric properties. The test was administered to control and clinical groups. Interrater and test-retest reliability were analyzed for each story in order to select the set of 10 stories included in the final reduced version. The shortened version showed good psychometric properties for controls and patients: test-retest reliability of 0.97 and 0.78, inter-rater reliability of 0.95 and 0.87 and Cronbach's alpha of 0.82 and 0.72.

Step-scan T cell-based differential Fourier transform infrared photoacoustic spectroscopy (DFTIR-PAS) for detection of ambient air contaminants

NASA Astrophysics Data System (ADS)

Liu, Lixian; Mandelis, Andreas; Huan, Huiting; Melnikov, Alexander

2016-10-01

A step-scan differential Fourier transform infrared photoacoustic spectroscopy (DFTIR-PAS) using a commercial FTIR spectrometer was developed theoretically and experimentally for air contaminant monitoring. The configuration comprises two identical, small-size and low-resonance-frequency T cells satisfying the conflicting requirements of low chopping frequency and limited space in the sample compartment. Carbon dioxide (CO2) IR absorption spectra were used to demonstrate the capability of the DFTIR-PAS method to detect ambient pollutants. A linear amplitude response to CO2 concentrations from 100 to 10,000 ppmv was observed, leading to a theoretical detection limit of 2 ppmv. The differential mode was able to suppress the coherent noise, thereby imparting the DFTIR-PAS method with a better signal-to-noise ratio and lower theoretical detection limit than the single mode. The results indicate that it is possible to use step-scan DFTIR-PAS with T cells as a quantitative method for high sensitivity analysis of ambient contaminants.

Comparison between Malassezia Folliculitis and Non-Malassezia Folliculitis

PubMed Central

Song, Hyo Sang; Kim, Sue Kyung

2014-01-01

Background Among the various types of folliculitis, differentiation of Malassezia folliculitis (MF) from other forms of folliculitis is important because it is usually treated with antifungal agents. Objective We attempted to find a method to enhance the detection rate of MF, and examined the differences in the clinical manifestation between MF and non-MF (NMF). Methods We performed a retrospective study involving patients with folliculitis who were previously diagnosed with MF or NMF on the basis of serial tissue sectioning and diastase-Periodic acid-Schiff (d-PAS) staining findings. The clinical features of MF and NMF were compared. Results Among a total of 100 folliculitis patients, 20 were diagnosed with MF and 80 with NMF. Tissues from the 80 patients with NMF were sectioned serially into 10 slices and stained with hematoxylin and eosin stain; among these, 10 had many round-to-oval yeast organisms in the hair follicles that confirmed MF. Finally, d-PAS staining was used to detect the presence of yeast in the NMF slides. Notably, among the 70 d-PAS-stained samples, yeast organisms were found in 6 samples, confirming MF. As a result, the diagnosis of 16 patients changed from NMF to MF. Compared with NMF, MF showed major involvement of the trunk and low involvement of the face and legs as well as male predilection. Conclusion Physicians should consider serial sectioning and/or d-PAS staining of folliculitis lesions, particularly of those on the trunk of male patients, even if no yeast organisms are detected initially. PMID:25324652

Synthesis, characterization and biological activity of some platinum(II) complexes with Schiff bases derived from salicylaldehyde, 2-furaldehyde and phenylenediamine.

PubMed

Gaballa, Akmal S; Asker, Mohsen S; Barakat, Atiat S; Teleb, Said M

2007-05-01

Four platinum(II) complexes of Schiff bases derived from salicylaldehyde and 2-furaldehyde with o- and p-phenylenediamine were reported and characterized based on their elemental analyses, IR and UV-vis spectroscopy and thermal analyses (TGA). The complexes were found to have the general formula [Pt(L)(H(2)O)(2)]Cl(2) x nH(2)O (where n=0 for complexes 1, 3, 4; n=1 for complex 2. The data obtained show that Schiff bases were interacted with Pt(II) ions in the neutral form as a bidentate ligand and the oxygens rather than the nitrogens are the most probable coordination sites. Square planar geometrical structure with two coordinated water molecules were proposed for all complexes The free ligands, and their metal complexes were screened for their antimicrobial activities against the following bacterial species: E. coli, B. subtilis, P. aereuguinosa, S. aureus; fungus A. niger, A. fluves; and the yeasts C. albican, S. cervisiea. The activity data show that the platinum(II) complexes are more potent antimicrobials than the parent Schiff base ligands against one or more microorganisms.

Localization and characterization of carbohydrates in adrenal medullary cells

PubMed Central

1975-01-01

The localization and characterization of carbohydrates in adrenal medullary cells were studied by histochemical and cytochemical methods. Adrenaline (A)-and noradrenaline (N)-storing granules were argentaphobic when ultrathin sections of Araldite-embedded medullae were stained according to the periodic acid-thiocarbohydrazide-silver proteinate technique of Thiery. A small amount of glycogen in the form of single beta-particles as well as lysosomes were, however, visualized by this technique. The entire core of the A granules was markedly positive after ultrathin sections of glutaraldehyde-fixed, glycol methacrylate (GMA)-embedded medullae were stained with phosphotungstic acid (PTA) at low pH (0.3). The N granules, in contrast, were mostly unreactive. In the A cells, PTA stained a large part of the Golgi complex, whereas in the N cells the Golgi complex was mostly unstained. In both cell types, the cell coat, lysosomes, and multivesticular bodies reacted to PTA. The periodic acid-Schiff (PAS) technique showed A but not N granules in semithin sections of GMA- or Araldite-embedded medullae. The PTA and PAS stains were abolished by acetylation, restored by saponification, unchanged by methylation, and greatly diminished by sulfation. In ultrathin sections of GMA- or Araldite- embedded medullae incubated with colloidal iron according to various techniques, the cell coat and lysosomes of both cell types were stained, unlike all the other cytoplasmic organelles. These results indicate that A granules and the Golgi complex of A cells, unlike the same structures in N cells, are rich in glycoproteins which are probably not acidic. PMID:47862

Polyamines Regulate Strawberry Fruit Ripening by Abscisic Acid, Auxin, and Ethylene.

PubMed

Guo, Jiaxuan; Wang, Shufang; Yu, Xiaoyang; Dong, Rui; Li, Yuzhong; Mei, Xurong; Shen, Yuanyue

2018-05-01

Polyamines (PAs) participate in many plant growth and developmental processes, including fruit ripening. However, it is not clear whether PAs play a role in the ripening of strawberry ( Fragaria ananassa ), a model nonclimacteric plant. Here, we found that the content of the PA spermine (Spm) increased more sharply after the onset of fruit coloration than did that of the PAs putrescine (Put) or spermidine (Spd). Spm dominance in ripe fruit resulted from abundant transcripts of a strawberry S -adenosyl-l-Met decarboxylase gene ( FaSAMDC ), which encodes an enzyme that generates a residue needed for PA biosynthesis. Exogenous Spm and Spd promoted fruit coloration, while exogenous Put and a SAMDC inhibitor inhibited coloration. Based on transcriptome data, up- and down-regulation of FaSAMDC expression promoted and inhibited ripening, respectively, which coincided with changes in several physiological parameters and their corresponding gene transcripts, including firmness, anthocyanin content, sugar content, polyamine content, auxin (indole-3-acetic acid [IAA]) content, abscisic acid (ABA) content, and ethylene emission. Using isothermal titration calorimetry, we found that FaSAMDC also had a high enzymatic activity with a K d of 1.7 × 10 -3 m In conclusion, PAs, especially Spm, regulate strawberry fruit ripening in an ABA-dominated, IAA-participating, and ethylene-coordinated manner, and FaSAMDC plays an important role in ripening. © 2018 American Society of Plant Biologists. All Rights Reserved.

Ammonium chloride catalyzed synthesis of novel Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitriles and evaluation of their antimicrobial and anti-breast cancer activities.

PubMed

Al-Shareef, Hossa F; Elhady, Heba A; Aboellil, Amany H; Hussein, Essam M

2016-01-01

Indolinone and spiro-indoline derivatives have been employed in the preparation of different important therapeutic compounds required for treatment of anticonvulsants, antibacterial, Antitubercular, and anticancer activities. Schiff bases have been found to possess various pharmacological activities such as antitubercular, plant growth inhibiting, insecticsidal, central nerve system depressant, antibacterial, anticancer, anti-inflammatory, and antimicrobial. Mannich bases have a variety of biological activities such as antibacterial and antifungal activities. In this study, a green, rapid and efficient protocol for the synthesis of a new series of Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitrile derivatives using ammonium chloride as a very inexpensive and readily available reagent. The prepared compounds were assessed in vitro for their antimicrobial activity. Also, the cytotoxic activity of the prepared compounds was assessed in vitro against human cells line MCF7 breast cancer. Good activity was distinguished for Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitriles, with some members recorded higher antimicrobial and anti-breast cancer activities.Graphical abstractNovel Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitriles.

Biologically active Schiff bases containing thiophene/furan ring and their copper(II) complexes: Synthesis, spectral, nonlinear optical and density functional studies

NASA Astrophysics Data System (ADS)

Gündüzalp, Ayla Balaban; Özsen, İffet; Alyar, Hamit; Alyar, Saliha; Özbek, Neslihan

2016-09-01

Schiff bases; 1,8-bis(thiophene-2-carboxaldimine)-p-menthane (L1) and 1,8-bis(furan-2-carboxaldimine)-p-menthane (L2) have been synthesized and characterized by elemental analysis, 1Hsbnd 13C NMR, UV-vis, FT-IR and LC-MS methods. 1H and 13C shielding tensors for L1 and L2 were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The vibrational band assignments, nonlinear optical (NLO) activities, frontier molecular orbitals (FMOs) and absorption spectrum have been investigated by the same basis set. Schiff base-copper(II) complexes have been synthesized and structurally characterized with spectroscopic methods, magnetic and conductivity measurements. The spectroscopic data suggest that Schiff base ligands coordinate through azomethine-N and thiophene-S/furan-O donors (as SNNS and ONNO chelating systems) to give a tetragonal geometry around the copper(II) ions. Schiff bases and Cu(II) complexes have been screened for their biological activities on different species of pathogenic bacteria, those are, Gram positive bacteria: Bacillus subtitilus, Yersinia enterotica, Bacillus cereus, Listeria monocytogenes, Micrococcus luteus and Gram negative bacteria: Escherichia coli, Pseudomonas aeroginosa, Shigella dysenteriae, Salmonella typhi, Klebsiella pseudomonas by using microdilution technique (MIC values in mM). Biological activity results show that Cu(II) complexes have higher activities than parent ligands and metal chelation may affect significantly the antibacterial behavior of the organic ligands.

The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration.

PubMed

Uarrota, Virgílio Gavicho; Moresco, Rodolfo; Schmidt, Eder Carlos; Bouzon, Zenilda Laurita; Nunes, Eduardo da Costa; Neubert, Enilto de Oliveira; Peruch, Luiz Augusto Martins; Rocha, Miguel; Maraschin, Marcelo

2016-04-15

This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total protein contents occurred from 3 to 5 days of storage and were correlated with the delay of PPD. Cassava samples stained with Periodic Acid-Schiff (PAS) highlighted the presence of starch and cellulose. Degradation of starch granules during PPD was also detected. Slight metachromatic reaction with toluidine blue is indicative of increasing of acidic polysaccharides and may play an important role in PPD delay. Principal component analysis (PCA) classified samples according to their levels of enzymatic activity based on the decision tree model which showed GPX and total protein amounts to be correlated with PPD. The Oriental (ORI) cultivar was more susceptible to PPD. Copyright © 2015 Elsevier Ltd. All rights reserved.

PAs and NPs in an emergency room-linked acute care clinic.

PubMed

Currey, C J

1984-12-01

The use of hospital emergency rooms for nonurgent care during evenings hours often strains medical resources and may affect the quality of emergency care. One facility's effective use of an after-hours acute care clinic staffed by PAs and NPs to divert nonurgent problems away from its emergency room is outlined. PAs and NPs work during peak demand hours (evenings and weekends) under the supervision of an emergency room physician, and receive supplementary support from other emergency room personnel. Incoming patients are referred to the emergency room or acute care clinic, depending on the nature of their problems. Acute care clinic patients are then treated by the PA or NP and either released or referred to an emergency room physician, if their conditions warrant additional treatment. As a result, use of the acute care clinic has greatly reduced the amount of non-urgent medical treatment in the emergency room and has provided other advantages to both patients and staff as well. These advantages and the encouraging statistics following six months of the clinic's operation are discussed.

Spectroscopic studies on two mono nuclear iron (III) complexes derived from a schiff base and an azodye

NASA Astrophysics Data System (ADS)

Mini, S.; Sadasivan, V.; Meena, S. S.; Bhatt, Pramod

2014-10-01

Two new mono nuclear Fe(III) complexes of an azodye (ANSN) and a Schiff base (FAHP) are reported. The azodye is prepared by coupling diazotized 1-amino-2-naphthol-4-sulphonicacid with 2-naphthol and the Schiff base is prepared by condensing 2-amino-3-hydroxy pyridine with furfural. The complexes were synthesized by the reaction of FeCl3˙2H2O with respective ligands. They were characterized on the basis of elemental analysis and spectral studies like IR, NMR, Electronic and M.ssbauer. Magnetic susceptibility and Molar conductance of complexes at room temperature were studied. Based on the spectroscopic evidences and other analytical data the complexes are formulated as[Fe(ANSN)Cl(H2O)2] and [Fe(FAHP)Cl2(H2O)2].

Synthesis and biological evaluation of novel 6-hydroxy-benzo[d][1,3]oxathiol-2-one Schiff bases as potential anticancer agents.

PubMed

Chazin, Eliza de Lucas; Sanches, Paola de Souza; Lindgren, Eric Brazil; Vellasco Júnior, Walcimar Trindade; Pinto, Laine Celestino; Burbano, Rommel Mario Rodríguez; Yoneda, Julliane Diniz; Leal, Kátia Zaccur; Gomes, Claudia Regina Brandão; Wardell, James Lewis; Wardell, Solange Maria Silva Veloso; Montenegro, Raquel Carvalho; Vasconcelos, Thatyana Rocha Alves

2015-01-27

With the aim of discovering new anticancer agents, we have designed and synthesized novel 6-hydroxy-benzo[d][1,3]oxathiol-2-one Schiff bases. The synthesis started with the selective nitration at 5-position of 6-hydroxybenzo[d][1,3]oxathiol-2-one (1) leading to the nitro derivative 2. The nitro group of 2 was reduced to give the amino intermediate 3. Schiff bases 4a-r were obtained from coupling reactions between 3 and various benzaldehydes and heteroaromatic aldehydes. All the new compounds were fully identified and characterized by NMR (1H and 13C) and specifically for 4q by X-ray crystallography. The in vitro cytotoxicity of the compounds was evaluated against cancer cell lines (ACP-03, SKMEL-19 and HCT-116) by using MTT assay. Schiff bases 4b and 4o exhibited promising cytotoxicity against ACP-03 and SKMEL-19, respectively, with IC50 values lower than 5 μM. This class of compounds can be considered as a good starting point for the development of new lead molecules in the fight against cancer.

Development of Inhibitors of the PAS-B Domain of the HIF-2α Transcription Factor

PubMed Central

Rogers, Jamie L.; Bayeh, Liela; Scheuermann, Thomas H.; Longgood, Jamie; Key, Jason; Naidoo, Jacinth; Melito, Lisa; Shokri, Cameron; Frantz, Doug E.; Bruick, Richard K.; Gardner, Kevin H.; MacMillan, John B.; Tambar, Uttam K.

2013-01-01

Hypoxia Inducible Factors (HIFs) are heterodimeric transcription factors induced in a variety of pathophysiological settings, including cancer. We describe the first detailed structure-activity-relationship study of small molecules designed to inhibit HIF-2α–ARNT heterodimerization by binding an internal cavity of the HIF-2α PAS-B domain. Through a series of biophysical characterizations of inhibitor/protein interactions (NMR and X-ray crystallography), we have established the structural requirements for artificial inhibitors of the HIF-2α–ARNT PAS-B interaction. These results may serve as a foundation for discovering therapeutic agents that function by a novel mode of action. PMID:23363003

Rational design and synthesis of 2-anilinopyridinyl-benzothiazole Schiff bases as antimitotic agents.

PubMed

Shaik, Thokhir B; Hussaini, S M Ali; Nayak, V Lakshma; Sucharitha, M Lakshmi; Malik, M Shaheer; Kamal, Ahmed

2017-06-01

Based on our previous results and literature precedence, a series of 2-anilinopyridinyl-benzothiazole Schiff bases were rationally designed by performing molecular modeling experiments on some selected molecules. The binding energies of the docked molecules were better than the E7010, and the Schiff base with trimethoxy group on benzothiazole moiety, 4y was the best. This was followed by the synthesis of a series of the designed molecules by a convenient synthetic route and evaluation of their anticancer potential. Most of the compounds have shown significant growth inhibition against the tested cell lines and the compound 4y exhibited good antiproliferative activity with a GI 50 value of 3.8µM specifically against the cell line DU145. In agreement with the docking results, 4y exerted cytotoxicity by the disruption of the microtubule dynamics by inhibiting tubulin polymerization via effective binding into colchicine domain, comparable to E7010. Detailed binding modes of 4y with colchicine binding site of tubulin were studied by molecular docking. Furthermore, 4y induced apoptosis as evidenced by biological studies like mitochondrial membrane potential, caspase-3, and Annexin V-FITC assays. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis and spectral characterization of Schiff base complexes of Cu(II), Co(II), Zn(II) and VO(IV) containing 4-(4-aminophenyl)morpholine derivatives: Antimicrobial evaluation and anticancer studies

NASA Astrophysics Data System (ADS)

Dhahagani, K.; Mathan Kumar, S.; Chakkaravarthi, G.; Anitha, K.; Rajesh, J.; Ramu, A.; Rajagopal, G.

2014-01-01

Metal(II) chelates of Schiff bases derived from the condensation of 4-morpholinoaniline with substituted salicylaldehyde have been prepared and characterized by 1H NMR, IR, electronic, EPR, and magnetic measurement studies. The complexes are of the type M(X-MPMP)2 [where M = Cu(II), Co(II)), Zn(II), or VO(IV); MPMP = 2-[(4 morpholinophenyl imino) methyl] 4-X-phenol, X = Cl, (L1H), X = Br (L2H)]. Single crystal X-ray crystallography studies confirm the structure of newly synthesized Schiff bases. The Schiff bases act as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The free ligands and metal complexes are screened for their biopotency. Metal complexes exhibit better activity than ligands. Anticancer activity of ligands and their metal complexes are evaluated in human heptocarcinoma(HepG2) cells. The preliminary bioassay indicates that the Schiff base and its zinc complex exhibit inhibitory activity against the human gastric cancer cell lines.

In Vitro Degradation of Pure Magnesium―The Effects of Glucose and/or Amino Acid

PubMed Central

Wang, Yu; Cui, Lan-Yue; Li, Shuo-Qi; Zou, Yu-Hong; Han, En-Hou

2017-01-01

The influences of glucose and amino acid (L-cysteine) on the degradation of pure magnesium have been investigated using SEM, XRD, Fourier transformed infrared (FTIR), X-ray photoelectron spectroscopy (XPS), polarization and electrochemical impedance spectroscopy and immersion tests. The results demonstrate that both amino acid and glucose inhibit the corrosion of pure magnesium in saline solution, whereas the presence of both amino acid and glucose accelerates the corrosion rate of pure magnesium. This may be due to the formation of -C=N- bonding (a functional group of Schiff bases) between amino acid and glucose, which restricts the formation of the protective Mg(OH)2 precipitates. PMID:28773085

Optical characterization of semiconductor materials by using FTIR-PAS

NASA Astrophysics Data System (ADS)

Arévalo, Fabiola; Saavedra, Renato; Paulraj, M.

2008-11-01

In this paper we discuss the procedures for photoacoustic measurements for semiconducting materials, including bulk samples like Gallium Antimonide (GaSb). The optical absorption at photon energies near the band gap was measured at room temperature using Fourier Transform Infrared Photoacoustic spectroscopy (FTIR-PAS). Measurements were performed using a NEXUS 670 FTIR-spectrometer (from Thermo Nicolet) with a MTEC model 300 PA cell (MTEC Photoacoustics, Inc.). Optical properties of the studied samples were determined from their room temperature PA spectra and band gaps were calculated directly from absorption spectra

Metal (II) Complexes Derived from Naphthofuran-2-carbohydrazide and Diacetylmonoxime Schiff Base: Synthesis, Spectroscopic, Electrochemical, and Biological Investigation

PubMed Central

Sumathi, R. B.; Halli, M. B.

2014-01-01

A new Schiff base and a new series of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) complexes were synthesized by the condensation of naphthofuran-2-carbohydrazide and diacetylmonoxime. Metal complexes of the Schiff base were prepared from their chloride salts of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) in ethanol. The ligand along with its metal complexes have been characterized on the basis of analytical data, IR, electronic, mass, 1HNMR, ESR spectral data, thermal studies, magnetic susceptibility, and molar conductance measurements. The nonelectrolytic behaviour of the complexes was assessed from the measured low conductance data. The elemental analysis of the complexes confirm the stoichiometry of the type CuL2Cl2 and MLCl2 where M = Ni(II), Co(II), Cd(II), and Hg(II) and L = Schiff base. The redox property of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In the light of these results, Co(II), Ni(II), and Cu(II) complexes are assigned octahedral geometry, Cd(II), and Hg(II) complexes tetrahedral geometry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleaving capacity of all the complexes was analysed by agarose gel electrophoresis method. PMID:24592203

One-pot microwave assisted synthesis under green chemistry conditions, antioxidant screening, and cytotoxicity assessments of benzimidazole Schiff bases and pyrimido[1,2-a]benzimidazol-3(4H)-ones.

PubMed

Neochoritis, Constantinos G; Zarganes-Tzitzikas, Tryfon; Tsoleridis, Constantinos A; Stephanidou-Stephanatou, Julia; Kontogiorgis, Christos A; Hadjipavlou-Litina, Dimitra J; Choli-Papadopoulou, Theodora

2011-01-01

The synthesis of a number of benzimidazole Schiff bases 3 and 3-oxo-pyrimido[1,2-a]benzimidazoles 4 in excellent yields by a one-step sequence from the reaction of 2-aminobenzimidazole under green chemistry conditions is described. Structural assignments of the new compounds as well as complete assignment of (1)H and (13)C NMR signals have been unambiguously achieved based on the analysis of their (1)H and (13)C NMR (1D and 2D), IR, MS and elemental analysis data. To the synthesized Schiff bases the E-configuration was assigned on the basis of comparison of experimental and calculated (DFT) (13)C NMR chemical shifts. Compounds 3 and 4 were evaluated as inhibitors of lipoxygenase (LOX) and of lipid peroxidation (LPO). All the tested derivatives showed inhibition of lipid peroxidation, whereas most of them were found to have higher activation than the reference compound trolox; The Schiff bases 3e, 3h, and 3i, and the pyrimidobenzimidazoles 4a, 4e and 4f were found to be the most potent. The most potent LOX inhibitor within the subset of Schiff bases was found compound 3i, followed by 3f, whereas compounds 4a and 4g were found the most potent of the 3-oxo-pyrimido[1,2-a]benzimidazole group. Moreover, some cytotoxicity assessments were undertaken, whereupon it was found that Schiff base 3i and pyrimidobenzimidazoles 4e and 4f did not exhibit cytotoxicity at similar concentrations resembling thus the inhibitory activity of lipid peroxidation. The most cytotoxic Schiff base and pyrimidobenzimidazole were found to be 3d and 4c, respectively. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Low-dose radiation pretreatment improves survival of human ceiling culture-derived proliferative adipocytes (ccdPAs) under hypoxia via HIF-1 alpha and MMP-2 induction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adachi, Naoki; Kubota, Yoshitaka, E-mail: kubota-cbu@umin.ac.jp; Kosaka, Kentarou

2015-08-07

Poor survival is a major problem of adipocyte transplantation. We previously reported that VEGF and MMPs secreted from transplanted adipocytes are essential for angiogenesis and adipogenesis. Pretreatment with low-dose (5 Gy) radiation (LDR) increased VEGF, MMP-2, and HIF-1 alpha mRNA expression in human ceiling culture-derived proliferative adipocytes (hccdPAs). Gene expression after LDR differed between adipose-derived stem cells (hASCs) and hccdPAs. Pretreatment with LDR improved the survival of hccdPAs under hypoxia, which is inevitable in the early stages after transplantation. Upregulation of VEGF and MMP-2 after LDR in hccdPAs is mediated by HIF-1 alpha expression. Our results suggest that pretreatment with LDRmore » may improve adipocyte graft survival in a clinical setting through upregulation of VEGF and MMP-2 via HIF-1 alpha. - Highlights: • Ceiling culture-derived proliferative adipocytes (ccdPAs) react to radiation. • Low-dose radiation (LDR) pretreatment improves survival of ccdPAs under hypoxia. • Gene expression after LDR differs between ccdPAs and adipose-derived stem cells. • LDR-induced increase in MMP-2 and VEGF is dependent on HIF-1 alpha induction. • LDR pretreatment may improve the adipocyte graft survival rate in clinical settings.« less

FTIR-PAS: a powerful tool for characterising the chemical composition and predicting the labile C fraction of various organic waste products.

PubMed

Bekiaris, Georgios; Bruun, Sander; Peltre, Clément; Houot, Sabine; Jensen, Lars S

2015-05-01

Fourier transform infrared (FT-IR) spectroscopy has been used for several years as a fast, low-cost, reliable technique for characterising a large variety of materials. However, the strong influence of sample particle size and the inability to measure the absorption of very dark and opaque samples have made FTIR unsuitable for many waste materials. FTIR-photoacoustic spectroscopy (FTIR-PAS) can eliminate some of the shortcomings of traditional FTIR caused by scattering effects and reflection issues, and recent advances in PAS technology have made commercial instruments available. In this study, FTIR-PAS was used to characterise a wide range of organic waste products and predict their labile carbon fraction, which is normally determined from time-consuming assays. FTIR-PAS was found to be capable of predicting the labile fraction of carbon as efficiently as near infrared spectroscopy (NIR) and furthermore of identifying the compounds that are correlated with the predicted parameter, thus facilitating a more mechanistic interpretation. Copyright © 2015 Elsevier Ltd. All rights reserved.

An IC-MS/MS Method for the Determination of 1-Hydroxyethylidene-1,1-diphosphonic Acid on Uncooked Foods Treated with Peracetic Acid-Based Sanitizers.

PubMed

Suzuki, Ippei; Kubota, Hiroki; Ohtsuki, Takashi; Tatebe, Chiye; Tada, Atsuko; Yano, Takeo; Akiyama, Hiroshi; Sato, Kyoko

2016-01-01

A rapid, sensitive, and specific analytical method for the determination of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) on uncooked foods after treatment with a peracetic acid-based sanitizer (PAS) was developed. The method involves simple sample preparation steps and analysis using ion chromatography (IC) coupled with tandem mass spectrometry (MS/MS). The quantification limits of HEDP on uncooked foods are 0.007 mg/kg for vegetables and fruits and 0.2 mg/kg for meats. The recovery and relative standard deviation (RSD) of HEDP analyses of uncooked foods ranged from 73.9 to 103.8% and 1.9 to 12.6%, respectively. The method's accuracy and precision were evaluated by inter-day recovery tests. The recovery for all samples ranged from 93.6 to 101.2%, and the within-laboratory repeatability and reproducibility were evaluated based on RSD values, which were less than 6.9 and 11.5%, respectively. Analyses of PAS-treated fruits and vegetables using the developed method indicated levels of HEDP ranging from 0.008 to 0.351 mg/kg. Therefore, the results of the present study suggest that the proposed method is an accurate, precise, and reliable way to determine residual HEDP levels on PAS-treated uncooked foods.

Matrix change of bone grafting substitute after implantation into guinea pig bulla.

PubMed

Punke, Ch; Zehlicke, T; Just, T; Holzhüter, G; Gerber, T; Pau, H W

2012-05-01

Many different surgical techniques have been developed to remove open mastoid cavities. In addition to autologous materials, alloplastic substances have been used. A very slow absorption of these materials and extrusion reactions have been reported. We investigated a newly developed, highly porous bone grafting material to eliminate open mastoid cavities, in an animal model. To characterise the transformation process, the early tissue reactions were studied in relation to the matrix transformation of the bone material. NanoBone (NB), a highly porous bone grafting material based on calcium phosphate and silica, was filled into the open bullae from 20 guinea pigs. The bullae were examined histologically. Energy dispersive X-ray spectroscopy (EDX) was used to investigate the change in the elemental composition at different sampling times. The surface topography of the sections was examined by electron microscopy. After 1 week, periodic acid-Schiffs (PAS) staining demonstrated accumulation of glycogen and proteins, particularly in the border area of the NB particles. After 2 weeks, the particles were evenly coloured after PAS staining. EDX analysis showed a rapid absorption of the silica in the bone grafting material. NanoBone showed a rapid matrix change after implantation in the bullae of guinea pigs. The absorption of the silica matrix and replacement by PAS-positive substances like glycoproteins and mucopolysaccharides seems to play a decisive role in the degradation processes of NB. This is associated with the good osteoinductive properties of the material.

Synthesis, crystal structure and bioactivity of manganese complexes with asymmetric chiral Schiff base

NASA Astrophysics Data System (ADS)

Zhang, Enfeng; Wei, Yi; Huang, Fuping; Yu, Qing; Bian, Hedong; Liang, Hong; Lei, Fuhou

2018-03-01

A couple of chiral unsymmtrical Schiff base ligands, (1R,2R) (-)chxn (salH) (naftalH) and (1S,2S) (-)chxn (salH) (naftalH) had been synthesized by the condensation of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with two isomers of (1R,2R)-trans-1,2-cyclohexanediamin and (1S,2S)-trans-1,2-cyclohexanediamin, respectively. At the same time, two manganese complexes have been synthesized and fully characterized by FT-IR spectrum, elemental analyses, single crystal X-ray diffraction. The interaction of the two Mn (III) complexes with bovine serum albumin (BSA) was investigated by spectroscopic techniques. The result reveals that the complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism. The binding constant and binding mode has been determined. The secondary structure and the amino acid residues microenvironment of BSA change in the presence of these complexes. SOD-like activity and ABTS free radical scavenging ability were also studied. The antioxidant capacity of the compounds showed that the complexes and their corresponding BSA adducts showed some SOD activity. The results of ABTS free radical scavenging showed that the activity of the BSA adduct was more obvious than that of the complex.

Unusual interaction of human apurinic/apyrimidinic endonuclease 1 (APE1) with abasic sites via the Schiff-base-dependent mechanism.

PubMed

Ilina, Ekaterina S; Khodyreva, Svetlana N; Lavrik, Olga I

2018-05-03

Clustered apurinic/apyrimidinic (AP) sites are more cytotoxic than isolated AP lesions because double strand breaks (DSB) can be formed during repair of closely positioned bistranded AP sites. Formation of DSB due to simultaneous cleavage of bistranded AP sites may be regulated by proteins specifically interacting with this complex lesion. A set of AP DNA duplexes containing AP sites in both strands in different mutual orientation (BS-AP DNAs) was used for search in the extracts of human cells proteins specifically recognizing clustered AP sites. A protein, which formed the Schiff-base-dependent covalent products having an apparent molecular mass of 50 kDa with the subset of BS-AP DNAs, was identified by mass spectrometry as apurinic/apyrimidinic endonuclease 1 (APE1). The identity of trapped protein was confirmed by Western blot analysis with anti-APE1 antibodies. Purified recombinant human APE1 is also capable of forming the 50 kDa-adducts with efficiency of BS-AP DNAs cross-linking to APE1 being dependent on the mutual orientation of AP sites. In spite of formation of the Schiff-base-dependent intermediate, which is prerequisite for the β-elimination mechanism, APE1 is unable to cleave AP sites. APE1 lacking the first 34 amino acids at the N-terminus, unlike wild type enzyme, is unable to form cross-links with BS-AP DNAs that testifies to the involvement of disordered N-terminal extension, which is enriched in lysine residues, in the interaction with AP sites. The yield of APE1-AP DNA cross-links was found to correlate with the enzyme amount in the extracts estimated by the immunochemical approach; therefore the BS-AP DNA-probes can be useful for comparative analysis of APE1 content in cell extracts. Copyright © 2018. Published by Elsevier B.V.

Calculation of the atomic electric dipole moment of Pb2+ induced by nuclear Schiff moment

NASA Astrophysics Data System (ADS)

Ramachandran, S. M.; Latha, K. V. P.; Meenakshisundaram, N.

2017-07-01

We report the atomic electric dipole moment induced by the P, T violating interactions in the nuclear/sub-nuclear level, for 207Pb2+ and 207Pb, owing to the recent interest in the ferroelectric crystal PbTiO3 as one of the candidates for investigating macroscopic P, T-odd effects. In this paper, we calculate the atomic electric dipole moments of 207Pb and Pb2+, parametrized in terms of the P, T-odd coupling parameter, the nuclear Schiff moment (NSM), S, in the frame-work of the coupled-perturbed Hartree-Fock theory. We estimate the Schiff moment of Pb2+ using the experimental result of a system, which is electronically similar to the Pb2+ ion. We present the dominant contributions of the electric dipole moment (EDM) matrix elements and the important correlation effects contributing to the atomic EDM of Pb2+. Our results provide the first ever calculated EDM of the Pb2+ ion, and an estimate of its NSM from which the P, T-odd energy shift in a PbTiO3 crystal can be evaluated.

32 CFR 806b.11 - When to give Privacy Act Statements (PAS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false When to give Privacy Act Statements (PAS). 806b... ADMINISTRATION PRIVACY ACT PROGRAM Collecting Personal Information § 806b.11 When to give Privacy Act Statements... information. Give a copy of the Privacy Act Statement if asked. Do not ask the person to sign the Privacy Act...

32 CFR 806b.11 - When to give Privacy Act Statements (PAS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false When to give Privacy Act Statements (PAS). 806b... ADMINISTRATION PRIVACY ACT PROGRAM Collecting Personal Information § 806b.11 When to give Privacy Act Statements... information. Give a copy of the Privacy Act Statement if asked. Do not ask the person to sign the Privacy Act...

32 CFR 806b.11 - When to give Privacy Act Statements (PAS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false When to give Privacy Act Statements (PAS). 806b... ADMINISTRATION PRIVACY ACT PROGRAM Collecting Personal Information § 806b.11 When to give Privacy Act Statements... information. Give a copy of the Privacy Act Statement if asked. Do not ask the person to sign the Privacy Act...

Synthesis of Schiff base 24-membered trivalent transition metal derivatives with their anti-inflammation and antimicrobial evaluation

NASA Astrophysics Data System (ADS)

Kumar, Gajendra; Devi, Shoma; Kumar, Dharmendra

2016-03-01

The paper presents the synthesis of macrocyclic complexes [{M(C52H36N12O4)X}X2] of Cr(III), Mn(III) and Fe(III) with Schiff base ligand (C52H36N12O4) obtained through the condensation of 1,4-dicarbonyl phenyl dihydrazide with 1,2-di(1H-indol-1-yl)ethane-1,2-dione. The newly formed Schiff base and its complexes have been characterized with the help of elemental analysis, condensation measurements, magnetic measurements and their structure configuration have been determined by various spectroscopic (electronic, IR, 1H NMR, 13C NMR, GCMS) techniques. The electronic spectra of the complexes indicate a five coordinate square pyramidal geometry of the center metal ion. These metal complexes and ligand were tested for their anti-inflammation and antimicrobial inhibiting potential and compared with standard drugs Phenyl butazone (anti-inflammation), Imipenem (antibacterial) and Miconazole (antifungal).

Synthesis and in vitro acetylcholinesterase and butyrylcholinesterase inhibitory potential of hydrazide based Schiff bases.

PubMed

Rahim, Fazal; Ullah, Hayat; Taha, Muhammad; Wadood, Abdul; Javed, Muhammad Tariq; Rehman, Wajid; Nawaz, Mohsan; Ashraf, Muhammad; Ali, Muhammad; Sajid, Muhammad; Ali, Farman; Khan, Muhammad Naseem; Khan, Khalid Mohammed

2016-10-01

To discover multifunctional agents for the treatment of Alzheimer's disease, a series of hydrazide based Schiff bases were designed and synthesized based on multitarget-directed strategy. We have synthesized twenty-eight analogs of hydrazide based Schiff bases, characterized by various spectroscopic techniques and evaluated in vitro for acetylcholinesterase and butyrylcholinesterase inhibition. All compounds showed varied degree of acetylcholinesterase and butyrylcholinesterase inhibition when compared with standard Eserine. Among the series, compounds 10, 3 and 24 having IC50 values 4.12±0.01, 8.12±0.01 and 8.41±0.06μM respectively showed potent acetylcholinesterase inhibition when compared with Eserine (IC50=0.85±0.0001μM). Three compounds 13, 24 and 3 having IC50 values 6.51±0.01, 9.22±0.07 and 37.82±0.14μM respectively showed potent butyrylcholinesterase inhibition by comparing with eserine (IC50=0.04±0.0001μM). The remaining compounds also exhibited moderate to weak inhibitory potential. Structure activity relationship has been established. Through molecular docking studies the binding interaction was confirmed. Copyright © 2016 Elsevier Inc. All rights reserved.

Ocular melanoma and mammary mucinous carcinoma in an African lion.

PubMed

Cagnini, Didier Q; Salgado, Breno S; Linardi, Juliana L; Grandi, Fabrizio; Rocha, Rafael M; Rocha, Noeme S; Teixeira, Carlos R; Del Piero, Fabio; Sequeira, Julio L

2012-09-25

Reports of neoplasms in Panthera species are increasing, but they are still an uncommon cause of disease and death in captive wild felids. The presence of two or more primary tumor in large felids is rarely reported, and there are no documented cases of ocular melanoma and mammary mucinous carcinoma in African lions. An ocular melanoma and a mammary mucinous carcinoma are described in an African lion (Panthera leo). The first tumour was histologically characterized by the presence of epithelioid and fusiform melanocytes, while the latter was composed of mucus-producing cells with an epithelial phenotype that contained periodic acid-Schiff (PAS) and Alcian blue staining mucins. Metastases of both tumor were identified in various organs and indirect immunohistochemistry was used to characterize them. Peribiliary cysts were observed in the liver. This is the first description of these tumor in African lions.

Very-Long-Chain Fatty Acids Are Involved in Polar Auxin Transport and Developmental Patterning in Arabidopsis[W

PubMed Central

Roudier, François; Gissot, Lionel; Beaudoin, Frédéric; Haslam, Richard; Michaelson, Louise; Marion, Jessica; Molino, Diana; Lima, Amparo; Bach, Liên; Morin, Halima; Tellier, Frédérique; Palauqui, Jean-Christophe; Bellec, Yannick; Renne, Charlotte; Miquel, Martine; DaCosta, Marco; Vignard, Julien; Rochat, Christine; Markham, Jonathan E.; Moreau, Patrick; Napier, Johnathan; Faure, Jean-Denis

2010-01-01

Very-long-chain fatty acids (VLCFAs) are essential for many aspects of plant development and necessary for the synthesis of seed storage triacylglycerols, epicuticular waxes, and sphingolipids. Identification of the acetyl-CoA carboxylase PASTICCINO3 and the 3-hydroxy acyl-CoA dehydratase PASTICCINO2 revealed that VLCFAs are important for cell proliferation and tissue patterning. Here, we show that the immunophilin PASTICCINO1 (PAS1) is also required for VLCFA synthesis. Impairment of PAS1 function results in reduction of VLCFA levels that particularly affects the composition of sphingolipids, known to be important for cell polarity in animals. Moreover, PAS1 associates with several enzymes of the VLCFA elongase complex in the endoplasmic reticulum. The pas1 mutants are deficient in lateral root formation and are characterized by an abnormal patterning of the embryo apex, which leads to defective cotyledon organogenesis. Our data indicate that in both tissues, defective organogenesis is associated with the mistargeting of the auxin efflux carrier PIN FORMED1 in specific cells, resulting in local alteration of polar auxin distribution. Furthermore, we show that exogenous VLCFAs rescue lateral root organogenesis and polar auxin distribution, indicating their direct involvement in these processes. Based on these data, we propose that PAS1 acts as a molecular scaffold for the fatty acid elongase complex in the endoplasmic reticulum and that the resulting VLCFAs are required for polar auxin transport and tissue patterning during plant development. PMID:20145257

A novel signal transduction protein: Combination of solute binding and tandem PAS-like sensor domains in one polypeptide chain.

PubMed

Wu, R; Wilton, R; Cuff, M E; Endres, M; Babnigg, G; Edirisinghe, J N; Henry, C S; Joachimiak, A; Schiffer, M; Pokkuluri, P R

2017-04-01

We report the structural and biochemical characterization of a novel periplasmic ligand-binding protein, Dret_0059, from Desulfohalobium retbaense DSM 5692, an organism isolated from Lake Retba, in Senegal. The structure of the protein consists of a unique combination of a periplasmic solute binding protein (SBP) domain at the N-terminal and a tandem PAS-like sensor domain at the C-terminal region. SBP domains are found ubiquitously, and their best known function is in solute transport across membranes. PAS-like sensor domains are commonly found in signal transduction proteins. These domains are widely observed as parts of many protein architectures and complexes but have not been observed previously within the same polypeptide chain. In the structure of Dret_0059, a ketoleucine moiety is bound to the SBP, whereas a cytosine molecule is bound in the distal PAS-like domain of the tandem PAS-like domain. Differential scanning flourimetry support the binding of ligands observed in the crystal structure. There is significant interaction between the SBP and tandem PAS-like domains, and it is possible that the binding of one ligand could have an effect on the binding of the other. We uncovered three other proteins with this structural architecture in the non-redundant sequence data base, and predict that they too bind the same substrates. The genomic context of this protein did not offer any clues for its function. We did not find any biological process in which the two observed ligands are coupled. The protein Dret_0059 could be involved in either signal transduction or solute transport. © 2017 The Protein Society.

The PAS domain-containing histidine kinase RpfS is a second sensor for the diffusible signal factor of Xanthomonas campestris.

PubMed

An, Shi-Qi; Allan, John H; McCarthy, Yvonne; Febrer, Melanie; Dow, J Maxwell; Ryan, Robert P

2014-05-01

A cell-cell signalling system mediated by the fatty acid signal DSF controls the virulence of Xanthomonas campestris pv. campestris (Xcc) to plants. The synthesis and recognition of the DSF signal depends upon different Rpf proteins. DSF signal generation requires RpfF whereas signal perception and transduction depends upon the sensor RpfC and regulator RpfG. Detailed analyses of the regulatory roles of different Rpf proteins have suggested the occurrence of further sensors for DSF. Here we have used a mutagenesis approach coupled with high-resolution transcriptional analysis to identify XC_2579 (RpfS) as a second sensor for DSF in Xcc. RpfS is a complex sensor kinase predicted to have multiple Per/Arnt/Sim (PAS) domains, a histidine kinase domain and a C-terminal receiver (REC) domain. Isothermal calorimetry showed that DSF bound to the isolated N-terminal PAS domain with a Kd of 1.4 μM. RpfS controlled expression of a sub-set of genes distinct from those controlled by RpfC to include genes involved in type IV secretion and chemotaxis. Mutation of XC_2579 was associated with a reduction in virulence of Xcc to Chinese Radish when assayed by leaf spraying but not by leaf inoculation, suggesting a role for RpfS-controlled factors in the epiphytic phase of the disease cycle. © 2014 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

An Investigation of Interrater Reliability for the Rorschach Performance Assessment System (R-PAS) in a Nonpatient U.S. Sample.

PubMed

Kivisalu, Trisha M; Lewey, Jennifer H; Shaffer, Thomas W; Canfield, Merle L

2016-01-01

The Rorschach Performance Assessment System (R-PAS) aims to provide an evidence-based approach to administration, coding, and interpretation of the Rorschach Inkblot Method (RIM). R-PAS analyzes individualized communications given by respondents to each card to code a wide pool of possible variables. Due to the large number of possible codes that can be assigned to these responses, it is important to consider the concordance rates among different assessors. This study investigated interrater reliability for R-PAS protocols. Data were analyzed from a nonpatient convenience sample of 50 participants who were recruited through networking, local marketing, and advertising efforts from January 2013 through October 2014. Blind recoding was used and discrepancies between the initial and blind coders' ratings were analyzed for each variable with SPSS yielding percent agreement and intraclass correlation values. Data for Location, Space, Contents, Synthesis, Vague, Pairs, Form Quality, Populars, Determinants, and Cognitive and Thematic codes are presented. Rates of agreement for 1,168 responses were higher for more simplistic coding (e.g., Location), whereas agreement was lower for more complex codes (e.g., Cognitive and Thematic codes). Overall, concordance rates achieved good to excellent agreement. Results suggest R-PAS is an effective method with high interrater reliability supporting its empirical basis.

Facile Synthesis, Characterization, and Antimicrobial Evaluation of Novel Heterocycles, Schiff Bases, and N-Nucleosides Bearing Phthalazine Moiety.

PubMed

Azab, Mohamed Emad; Rizk, Sameh Ahmed; Mahmoud, Naglaa Fawzy

2016-01-01

The present work describes convenient synthesis of the novel Schiff bases 5a and b by reacting phthalazinones 4a and b with 4-methoxybenzaldehyde Reaction of the Schiff bases with phenylisothiocyanate afforded diazetidine derivatives 7a and b. Also, compounds 4a and b reacted with 2-bromoglucoside tetraacetate giving peracetylated N-glycosides 6a and b, which were deacetylated to afford N-glycosylated phthalazinones 8a and b. On the other hand, when compound 3 was treated with POCl3/PCl5 and/or ethyl chloroacetate, chlorophthalazine and ethyl acetate derivatives 9 and 10 were obtained, respectively. Hydrazinolysis of compounds 9 and 10 produced the hydrazino and hydrazide derivatives 11 and 12, respectively. When compound 11 reacted with 2-furanaldehyde, acetic anhydride, and/or carbon disulphide, it gave compounds 13-15, respectively. Treatment of the hydrazide 12 with aromatic aldehydes, acetic anhydride, ethyl acetoacetate, acetyl acetone, ammonium thiocyanate, and/or phthalic anhydride furnished compounds 17-21. Meanwhile, reacting Schiff base 22 with the chlorophthalazine derivative 9 produced compound 23, which on treatment with furoyl chloride produced compound 24. The structures of the novel compounds were confirmed by IR, (1)H-NMR, (13)C-NMR, MS, and elemental analysis. The newly synthesized compounds were tested against Bacillus subtilis and Staphylococcus aureus as Gram-positive bacteria, Escherichia coli and Pseudomonas aurignosa as Gram-negative bacteria, and Candida albicans and Aspergillus niger as fungi strains. Compounds 5a and b, 23, and 24 showed greater antimicrobial activity than the stranded compounds, suggesting that they could be considered as promising antimicrobial agents.

Computational studies on nonlinear optical property of novel Wittig-based Schiff-base ligands and copper(II) complex

NASA Astrophysics Data System (ADS)

Rajasekhar, Bathula; Patowary, Nidarshana; K. Z., Danish; Swu, Toka

2018-07-01

Hundred and forty-five novel molecules of Wittig-based Schiff-base (WSB), including copper(II) complex and precursors, were computationally screened for nonlinear optical (NLO) properties. WSB ligands were derived from various categories of amines and aldehydes. Wittig-based precursor aldehydes, (E)-2-hydroxy-5-(4-nitrostyryl)benzaldehyde (f) and 2-hydroxy-5-((1Z,3E)-4-phenylbuta-1,3-dien-1-yl) benzaldehyde (g) were synthesised and spectroscopically confirmed. Schiff-base ligands and copper(II) complex were designed, optimised and their NLO property was studied using GAUSSIAN09 computer program. For both optimisation and hyperpolarisability (finite-field approach) calculations, Density Functional Theory (DFT)-based B3LYP method was applied with LANL2DZ basis set for metal ion and 6-31G* basis set for C, H, N, O and Cl atoms. This is the first report to present the structure-activity relationship between hyperpolarisability (β) and WSB ligands containing mono imine group. The study reveals that Schiff-base ligands of the category N-2, which are the ones derived from the precursor aldehyde, 2-hydroxy-5-(4nitro-styryl)benzaldehyde and pre-polarised WSB coordinated with Cu(II), encoded as Complex-1 (β = 14.671 × 10-30 e.s.u) showed higher β values over other categories, N-1 and N-3, i.e. WSB derived from precursor aldehydes, 2-hydroxy-5-styrylbenzaldehyde and 2-hydroxy-5-((1Z,3E)-4-phenylbuta-1,3-dien-1-yl)benzaldehyde, respectively. For the first time here we report the geometrical isomeric effect on β value.

Psychometric Properties and Norms of the German ABC-Community and PAS-ADD Checklist

ERIC Educational Resources Information Center

Zeilinger, Elisabeth L.; Weber, Germain; Haveman, Meindert J.

2011-01-01

Aim: The aim of the present study was to standardize and generate psychometric evidence of the German language versions of two well-established English language mental health instruments: the "Aberrant Behavior Checklist-Community" (ABC-C) and the "Psychiatric Assessment Schedule for Adults with Developmental Disabilities" (PAS-ADD) Checklist. New…

Peer Relations and the Understanding of Faux Pas: Longitudinal Evidence for Bidirectional Associations

ERIC Educational Resources Information Center

Banerjee, Robin; Watling, Dawn; Caputi, Marcella

2011-01-01

Research connecting children's understanding of mental states to their peer relations at school remains scarce. Previous work by the authors demonstrated that children's understanding of mental states in the context of a faux pas--a social blunder involving unintentional insult--is associated with concurrent peer rejection. The present report…

Hyperpolarization of Nitrogen-15 Schiff Bases by Reversible Exchange Catalysis with para-Hydrogen.

PubMed

Logan, Angus W J; Theis, Thomas; Colell, Johannes F P; Warren, Warren S; Malcolmson, Steven J

2016-07-25

NMR with thermal polarization requires relatively concentrated samples, particularly for nuclei with low abundance and low gyromagnetic ratios, such as (15) N. We expand the substrate scope of SABRE, a recently introduced hyperpolarization method, to allow access to (15) N-enriched Schiff bases. These substrates show fractional (15) N polarization levels of up to 2 % while having only minimal (1) H enhancements. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gain-of-function Mutations Cluster in Distinct Regions Associated with the Signaling Pathway in the PAS Domain of the Aerotaxis Receptor, Aer

PubMed Central

Campbell, Asharie J.; Watts, Kylie J.; Johnson, Mark S.; Taylor, Barry L.

2010-01-01

Summary The Aer receptor monitors internal energy (redox) levels in Escherichia coli with an FAD-containing PAS domain. Here, we randomly mutagenized the region encoding residues 14 to 119 of the PAS domain and found 72 aerotaxis-defective mutants, 24 of which were gain-of-function, signal-on mutants. The mutations were mapped onto an Aer homology model based on the structure of the PAS-FAD domain in NifL from Azotobacter vinlandii. Signal-on lesions clustered in the FAD binding pocket, the β-scaffolding and in the N-cap loop. We suggest that the signal-on lesions mimic the “signal-on” state of the PAS domain, and therefore may be markers for the signal-in and signal-out regions of this domain. We propose that the reduction of FAD rearranges the FAD binding pocket in a way that repositions the β-scaffolding and the N-cap loop. The resulting conformational changes are likely to be conveyed directly to the HAMP domain, and on to the kinase control module. In support of this hypothesis, we demonstrated disulfide band formation between cysteines substituted at residues N98C or I114C in the PAS β-scaffold and residue Q248C in the HAMP AS-2 helix. PMID:20545849

The presence of glutamate residues on the PAS sequence of the stimuli-sensitive nano-ferritin improves in vivo biodistribution and mitoxantrone encapsulation homogeneity.

PubMed

Falvo, Elisabetta; Malagrinò, Francesca; Arcovito, Alessandro; Fazi, Francesco; Colotti, Gianni; Tremante, Elisa; Di Micco, Patrizio; Braca, Aldo; Opri, Roberta; Giuffrè, Alessandro; Fracasso, Giulio; Ceci, Pierpaolo

2018-04-10

A genetically engineered human ferritin heavy chain (HFt)-based construct has been recently shown by our group to efficiently entrap and deliver doxorubicin to cancer cells. This construct, named HFt-MP-PAS, contained a tumor-selective sequence (MP) responsive to proteolytic cleavage by tumor proteases (MMPs), located between each HFt subunit and an outer shielding polypeptide sequence rich in proline (P), serine (S) and alanine (A) residues (PAS). HFt-MP-PAS displayed excellent therapeutic efficacy in xenogenic pancreatic and head and neck cancer models in vivo, leading to a significant increase in overall animal survivals. Here we report a new construct obtained by the genetic insertion of two glutamate residues in the PAS sequence of HFt-MP-PAS. Such new construct, named HFt-MP-PASE, is characterized by improved performances as drug biodistribution in a xenogenic pancreatic cancer model in vivo. Moreover, HFt-MP-PASE efficiently encapsulates the anti-cancer drug mitoxantrone (MIT), and the resulting MIT-loaded nanoparticles proved to be more soluble and monodispersed than the HFt-MP-PAS counterparts. Importantly, in vitro MIT-loaded HFt-MP-PASE kills several cancer cell lines of different origin (colon, breast, sarcoma and pancreas) at least as efficiently as the free drug. Finally, our MIT loaded protein nanocages allowed in vivo an impressive incrementing of the drug accumulation in the tumor with respect to the free drug. Copyright © 2018 Elsevier B.V. All rights reserved.

Reactivity of nitrido complexes of ruthenium(VI), osmium(VI), and manganese(V) bearing Schiff base and simple anionic ligands.

PubMed

Man, Wai-Lun; Lam, William W Y; Lau, Tai-Chu

2014-02-18

Nitrido complexes (M≡N) may be key intermediates in chemical and biological nitrogen fixation and serve as useful reagents for nitrogenation of organic compounds. Osmium(VI) nitrido complexes bearing 2,2':6',2″-terpyridine (terpy), 2,2'-bipyridine (bpy), or hydrotris(1-pyrazolyl)borate anion (Tp) ligands are highly electrophilic: they can react with a variety of nucleophiles to generate novel osmium(IV)/(V) complexes. This Account describes our recent results studying the reactivity of nitridocomplexes of ruthenium(VI), osmium(VI), and manganese(V) that bear Schiff bases and other simple anionic ligands. We demonstrate that these nitrido complexes exhibit rich chemical reactivity. They react with various nucleophiles, activate C-H bonds, undergo N···N coupling, catalyze the oxidation of organic compounds, and show anticancer activities. Ruthenium(VI) nitrido complexes bearing Schiff base ligands, such as [Ru(VI)(N)(salchda)(CH3OH)](+) (salchda = N,N'-bis(salicylidene)o-cyclohexyldiamine dianion), are highly electrophilic. This complex reacts readily at ambient conditions with a variety of nucleophiles at rates that are much faster than similar reactions using Os(VI)≡N. This complex also carries out unique reactions, including the direct aziridination of alkenes, C-H bond activation of alkanes and C-N bond cleavage of anilines. The addition of ligands such as pyridine can enhance the reactivity of [Ru(VI)(N)(salchda)(CH3OH)](+). Therefore researchers can tune the reactivity of Ru≡N by adding a ligand L trans to nitride: L-Ru≡N. Moreover, the addition of various nucleophiles (Nu) to Ru(VI)≡N initially generate the ruthenium(IV) imido species Ru(IV)-N(Nu), a new class of hydrogen-atom transfer (HAT) reagents. Nucleophiles also readily add to coordinated Schiff base ligands in Os(VI)≡N and Ru(VI)≡N complexes. These additions are often stereospecific, suggesting that the nitrido ligand has a directing effect on the incoming nucleophile. M≡N is also

Synthesis and biological evaluation of novel aromatic and heterocyclic bis-sulfonamide Schiff bases as carbonic anhydrase I, II, VII and IX inhibitors.

PubMed

Akocak, Suleyman; Lolak, Nabih; Nocentini, Alessio; Karakoc, Gulcin; Tufan, Anzel; Supuran, Claudiu T

2017-06-15

A series of sixteen novel aromatic and heterocyclic bis-sulfonamide Schiff bases were prepared by conjugation of well known aromatic and heterocyclic aminosulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor pharmacophores with aromatic and heterocyclic bis-aldehydes. The obtained bis-sulfonamide Schiff bases were investigated as inhibitors of four selected human (h) CA isoforms, hCA I, hCA II, hCA VII and hCA IX. Most of the newly synthesized compounds showed a good inhibitory profile against isoforms hCA II and hCA IX, also showing moderate selectivity against hCA I and VII. Several efficient lead compounds were identified among this bis-sulfonamide Schiff bases with low nanomolar to sub-nanomolar activity against hCA II (K i s ranging between 0.4 and 861.1nM) and IX (K i s between 0.5 and 933.6nM). Since hCA II and hCA IX are important drug targets (antiglaucoma and anti-tumor agents), these isoform-selective inhibitors may be considered of interest for various biomedical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mathematical Justification of Expression-Based Pathway Activation Scoring (PAS).

PubMed

Aliper, Alexander M; Korzinkin, Michael B; Kuzmina, Natalia B; Zenin, Alexander A; Venkova, Larisa S; Smirnov, Philip Yu; Zhavoronkov, Alex A; Buzdin, Anton A; Borisov, Nikolay M

2017-01-01

Although modeling of activation kinetics for various cell signaling pathways has reached a high grade of sophistication and thoroughness, most such kinetic models still remain of rather limited practical value for biomedicine. Nevertheless, recent advancements have been made in application of signaling pathway science for real needs of prescription of the most effective drugs for individual patients. The methods for such prescription evaluate the degree of pathological changes in the signaling machinery based on two types of data: first, on the results of high-throughput gene expression profiling, and second, on the molecular pathway graphs that reflect interactions between the pathway members. For example, our algorithm OncoFinder evaluates the activation of molecular pathways on the basis of gene/protein expression data in the objects of the interest.Yet, the question of assessment of the relative importance for each gene product in a molecular pathway remains unclear unless one call for the methods of parameter sensitivity /stiffness analysis in the interactomic kinetic models of signaling pathway activation in terms of total concentrations of each gene product.Here we show two principal points: 1. First, the importance coefficients for each gene in pathways that were obtained using the extremely time- and labor-consuming stiffness analysis of full-scaled kinetic models generally differ from much easier-to-calculate expression-based pathway activation score (PAS) not more than by 30%, so the concept of PAS is kinetically justified. 2. Second, the use of pathway-based approach instead of distinct gene analysis, due to the law of large numbers, allows restoring the correlation between the similar samples that were examined using different transcriptome investigation techniques.

Gastric mucosal defence mechanism during stress of pyloric obstruction in albino rats.

PubMed

Somasundaram, K; Ganguly, A K

1987-04-01

1. The integrity of the gastric mucosa and its ability to secrete mucus are believed to be essential for protection of gastric mucosa against ulceration induced by aggressive factors active in any stress situation. This study involves a three-compartmental analysis of gastric mucosal barrier in pylorus-ligated albino rats. 2. Quantitative analyses of histologically identifiable gastric mucosal epithelial neutral glycoproteins and gastric adherent mucus from oxyntic and pyloric gland areas, and components of non-dialysable mucosubstances in gastric secretion were made under stress of pyloric obstruction for 4, 8, and 16 h durations. Epithelial mucin was identified by periodic acid-Schiff (PAS) staining technique and assessed from the ratio of gastric mucosal thickness to the depth of PAS positive materials in it. The remaining visible mucus adhered to the gastric mucosa was estimated by Alcian blue binding technique. The results were compared with that of identical control groups. 3. A significant reduction in mucosal epithelial PAS positive materials after 8 or 16 h of pylorus ligation was observed. 4. The Alcian blue binding capacity of the pyloric gland area was increased significantly after 4 h of pylorus ligation, while after 8 or 16 h it was reduced in both oxyntic and pyloric gland areas. 5. Significant reductions in the rate of gastric secretion and volume, as well as concentration of the components of non-dialysable mucosubstances, were observed, indicating decreased synthesis of mucus glycoproteins. 6. Disruption of the mucosal barrier may have occurred due to decreased mucus synthesis and acid-pepsin accumulation; both could be due to stress associated with gastric distension. 7. The present findings confirm the role of mucus in protecting the underlying gastric epithelium during stress. The adherent mucus offers a first line of defence and epithelial mucus a second line of defence.

Determination of trace heavy metals in soil and sediments by atomic spectrometry following preconcentration with Schiff bases on Amberlite XAD-4.

PubMed

Kara, Derya; Fisher, Andrew; Hill, Steve J

2009-06-15

A matrix separation and analyte preconcentration system using Amberlite XAD copolymer resins functionalized by Schiff base reactions coupled with atomic spectrometry has been developed. Three different functionalized Amberlite XAD resins were synthesized using 4-phenylthiosemicarbazide, 2,3-dihydroxybenzaldehyde and 2-thiophenecarboxaldehyde as reagents. These resins could be used to preconcentrate transition and other trace heavy metal analytes from nitric acid digests of soil and sediment samples. Analyte retention was shown to work well at pH 6.0. After treatment of the digests with sodium fluoride and buffering to pH 6, samples that contain extremely large concentrations of iron were analysed for trace analytes without the excess iron overloading the capacity of the resin. The analytes Cd, Co, Cu, Ni and Pb were preconcentrated from acid extracts of certified soil/sediment samples and then eluted with 0.1M HNO(3) directly to the detection system. Flame atomic absorption spectrometry was used as a means of detection during the studies. The efficiency of the chelating resin and the accuracy of the proposed method were evaluated by the analysis of soil (SO-2) and sediment (LGC 6157 and MESS-3) certified reference materials.

Two novel macroacyclic schiff bases containing bis-N 2O 2 donor set and their binuclear complexes: synthesis, spectroscopic and magnetic properties

NASA Astrophysics Data System (ADS)

Karaoglu, Kaan; Baran, Talat; Serbest, Kerim; Er, Mustafa; Degirmencioglu, Ismail

2009-03-01

Herein, we report two novel macroacyclic Schiff bases derived from tetranaphthaldehyde derivative compound and their binuclear Mn(II), Ni(II), Cu(II) and Zn(II) complexes. The structures of the compounds have been proposed by elemental analyses, spectroscopic data i.e. IR, 1H and 13C NMR, UV-Vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The stoichiometries of the complexes derived from mass and elemental analysis correspond to the general formula [M 2L(ClO 4) n](ClO 4) 4-n, (where M is Mn(II), Ni(II), Cu(II), Zn(II) and L represents the Schiff base ligands).

Antioxidant, electrochemical, thermal, antimicrobial and alkane oxidation properties of tridentate Schiff base ligands and their metal complexes

NASA Astrophysics Data System (ADS)

Ceyhan, Gökhan; Çelik, Cumali; Uruş, Serhan; Demirtaş, İbrahim; Elmastaş, Mahfuz; Tümer, Mehmet

2011-10-01

In this study, two Schiff base ligands (HL 1 and HL 2) and their Cu(II), Co(II), Ni(II), Pd(II) and Ru(III) metal complexes were synthesized and characterized by the analytical and spectroscopic methods. Alkane oxidation activities of the metal complexes were studied on cyclohexane as substrate. The ligands and their metal complexes were evaluated for their antimicrobial activity against Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus and Enterococcus faecalis (as Gram-positive bacteria) and Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica, Klebsiella fragilis, Saccharomyces cerevisiae, and Candida albicans (as Gram-negative bacteria). The antioxidant properties of the Schiff base ligands were evaluated in a series of in vitro tests: 1,1-diphenyl-2-picrylhydrazyl (DPPH rad ) free radical scavenging and reducing power activity of superoxide anion radical generated non-enzymatic systems. Electrochemical and thermal properties of the compounds were investigated.

Binary and ternary copper(II) complexes of a new Schiff base ligand derived from 4-acetyl-5,6-diphenyl-3(2H)-pyridazinone: Synthesis, spectral, thermal, antimicrobial and antitumor studies

NASA Astrophysics Data System (ADS)

Shebl, Magdy; Adly, Omima M. I.; Abdelrhman, Ebtesam M.; El-Shetary, B. A.

2017-10-01

A new Schiff base ligand was synthesized by the reaction of 4-acetyl-5,6-diphenyl-3(2H)-pyridazinone with ethylenediamine. A series of binary copper(II) Schiff base complexes have been synthesized by using various copper(II) salts; AcO-, NO3-, ClO4-, Cl- and Br-. Ternary complexes were synthesized by using auxiliary ligands (L‧) [N,O-donor; 8-hydroxyquinoline and glycine or N,N-donor; 1,10-phenanthroline, bipyridyl and 2-aminopyridine]. The structures of the Schiff base and its complexes were characterized by elemental and thermal analyses, IR, electronic, mass, 1H NMR and ESR spectra in addition to conductivity and magnetic susceptibility measurements. The obtained complexes include neutral binuclear complexes as well as neutral and cationic mononuclear complexes according to the anion used and the experimental conditions. The ESR spin Hamiltonian parameters of some complexes were calculated and discussed. The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. Kinetic parameters (Ea, A, ΔH, ΔS and ΔG) of the thermal decomposition stages were evaluated using Coats-Redfern equations. The antimicrobial activity of the Schiff base and its complexes was screened against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus). The antitumor activity of the Schiff base and some of its Cu(II) complexes was investigated against HepG-2 cell line.

[Gardner syndrome--parent alienation syndrome (PAS). Diagnosis or family reality?].

PubMed

Namysłowska, Irena; Heitzman, Janusz; Siewierska, Anna

2009-01-01

The authors present characteristics of Parental Alienation Syndrome (PAS) proposed by Gardner as well as data, which may help to differentiate that syndrome with real psychological, physical and sexual abuse. The consequences of Gardner Syndrome for legal decisions in the court cases of child custody and the critique of this syndrome in forensic and psychiatric literature are also discussed, and several questions posed. Authors propose to treat Gardner Syndrome not as as a child disorder but as a specific, dynamic family situation, which occurs sometimes, during divorce and fight about child custody.

Effects of room airflow on accurate determination of PUF-PAS sampling rates in the indoor environment.

PubMed

Herkert, Nicholas J; Hornbuckle, Keri C

2018-05-23

Accurate and precise interpretation of concentrations from polyurethane passive samplers (PUF-PAS) is important as more studies show elevated concentrations of PCBs and other semivolatile air toxics in indoor air of schools and homes. If sufficiently reliable, these samplers may be used to identify local sources and human health risks. Here we report indoor air sampling rates (Rs) for polychlorinated biphenyl congeners (PCBs) predicted for a frequently used double-dome and a half-dome PUF-PAS design. Both our experimentally calibrated (1.10 ± 0.23 m3 d-1) and modeled (1.08 ± 0.04 m3 d-1) Rs for the double-dome samplers compare well with literature reports for similar rooms. We determined that variability of wind speeds throughout the room significantly (P < 0.001) effected uptake rates. We examined this effect using computational fluid dynamics modeling and 3-D sonic anemometer measurements and found the airflow dynamics to have a significant but small impact on the precision of calculated airborne concentrations. The PUF-PAS concentration measurements were within 27% and 10% of the active sampling concentration measurements for the double-dome and half-dome designs, respectively. While the half-dome samplers produced more consistent concentration measurements, we find both designs to perform well indoors.

Synthesis and luminescence properties of polymer-rare earth complexes containing salicylaldehyde-type bidentate Schiff base ligand.

PubMed

Zhang, Dandan; Gao, Baojiao; Li, Yanbin

2017-08-01

Using molecular design and polymer reactions, two types of bidentate Schiff base ligands, salicylaldehyde-aniline (SAN) and salicylaldehyde-cyclohexylamine (SCA), were synchronously synthesized and bonded onto the side chain of polysulfone (PSF), giving two bidentate Schiff base ligand-functionalized PSFs, PSF-SAN and PSF-SCA, referred to as macromolecular ligands. Following coordination reactions between the macromolecular ligands and Eu(III) and Tb(III) ions (the reaction occurred between the bonded ligands SAN or SCA and the lanthanide ion), two series of luminescent polymer-rare earth complexes, PSF-SAN-Eu(III) and PSF-SCA-Tb(III), were obtained. The two macromolecular ligands were fully characterized by Fourier transform infrared (FTIR), 1 H NMR and UV absorption spectroscopy, and the prepared complexes were also characterized by FTIR, UV absorption spectroscopy and thermo-gravity analysis. On this basis, the photoluminescence properties of these complexes and the relationships between their structure and luminescence were investigated in depth. The results show that the bonded bidentate Schiff base ligands, SAN and SCA, can effectively sensitize the fluorescence emission of Eu(III) and Tb(III) ions, respectively. PSF-SAN-Eu(III) series complexes, namely the binary complex PSF-(SAN) 3 -Eu(III) and the ternary complex PSF-(SAN) 3 -Eu(III)-(Phen) 1 (Phen is the small-molecule ligand 1,10-phenanthroline), produce strong red luminescence, suggesting that the triplet state energy level of SAN is lower and well matched with the resonant energy level of the Eu(III) ion. By contrast, PSF-SAN-Eu(III) series complexes, namely the binary complex PSF-(SCA) 3 -Tb(III) and the ternary complex PSF-(SCA) 3 -Tb(III)-(Phen) 1 , display strong green luminescence, suggesting that the triplet state energy level of SCA is higher and is well matched with the resonant energy level of Tb(III). Copyright © 2017 John Wiley & Sons, Ltd.

Structural characterization of new Schiff bases of sulfamethoxazole and sulfathiazole, their antibacterial activity and docking computation with DHPS protein structure.

PubMed

Mondal, Sudipa; Mandal, Santi M; Mondal, Tapan Kumar; Sinha, Chittaranjan

2015-01-01

New Schiff bases (1, 2) of substituted salicylaldehydes and sulfamethoxazole (SMX)/sulfathiazole (STZ) are synthesized and characterized by elemental analysis and spectroscopic data. Single crystal X-ray structure of one of the compounds (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(5-methylisoxazol-3-yl)benzenesulfonamide (1c) has been determined. Antimicrobial activities of the Schiff bases and parent sulfonamides (SMX, STZ) have been examined against several Gram-positive and Gram-negative bacteria and sulfonamide resistant pathogens; the lowest MIC is observed for (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(thiazol-2-yl)benzene sulfonamide (2c) (8.0 μg mL(-1)) and (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(5-methylisoxazol-3-yl)benzene sulfonamide (1c) (16.0 μg mL(-1)) against sulfonamide resistant pathogens. DFT optimized structures of the Schiff bases have been used to carry out molecular docking studies with DHPS (dihydropteroate synthase) protein structure (downloaded from Protein Data Bank) using Discovery Studio 3.5 to find the most preferred binding mode of the ligand inside the protein cavity. The theoretical data have been well correlated with the experimental results. Cell viability assay and ADMET studies predict that 1c and 2c have good drug like characters. Copyright © 2015 Elsevier B.V. All rights reserved.

Cr(III), Fe(III) and Co(III) complexes of tetradentate (ONNO) Schiff base ligands: Synthesis, characterization, properties and biological activity

NASA Astrophysics Data System (ADS)

Keskioğlu, Eren; Gündüzalp, Ayla Balaban; Çete, Servet; Hamurcu, Fatma; Erk, Birgül

2008-08-01

A series of metal complexes were synthesized from equimolar amounts of Schiff bases: 1,4-bis[3-(2-hydroxy-1-naphthaldimine)propyl]piperazine (bappnaf) and 1,8-bis[3-(2-hydroxy-1-naphthaldimine)- p-menthane (damnaf) with metal chlorides. All of synthesized compounds were characterized by elemental analyses, spectral (UV-vis, IR, 1H- 13C NMR, LC-MS) and thermal (TGA-DTA) methods, magnetic and conductance measurements. Schiff base complexes supposed in tetragonal geometry have the general formula [M(bappnaf or damnaf)]Cl· nH 2O, where M = Cr(III), Co(III) and n = 2, 3. But also Fe(III) complexes have octahedral geometry by the coordination of two water molecules and the formula is [Fe(bappnaf or damnaf)(H 2O) 2]Cl. The changes in the selected vibration bands in FT-IR indicate that Schiff bases behave as (ONNO) tetradentate ligands and coordinate to metal ions from two phenolic oxygen atoms and two azomethine nitrogen atoms. Conductance measurements suggest 1:1 electrolytic nature of the metal complexes. The synthesized compounds except bappnaf ligand have the antimicrobial activity against the bacteria: Escherichia coli (ATCC 11230), Yersinia enterocolitica (ATCC 1501), Bacillus magaterium (RSKK 5117), Bacillus subtilis (RSKK 244), Bacillus cereus (RSKK 863) and the fungi: Candida albicans (ATCC 10239). These results have been considerably interest in piperazine derivatives due to their significant applications in antimicrobial studies.

Pharmacological performance of novel poly-(ionic liquid)-grafted chitosan-N-salicylidene Schiff bases and their complexes.

PubMed

Elshaarawy, Reda F M; Refaee, Ayaat A; El-Sawi, Emtithal A

2016-08-01

In our endeavor to develop a new class of pharmacological candidates with antimicrobial and anticancer efficacy, a series of biopolymeric chitosan Schiff bases bearing salicylidene ionic liquid (IL-Sal) brushes (ILCSB1-3, poly-(GlcNHAc-GlcNH2-(GlcN-Sal-IL)) was successfully synthesized by adopting efficient synthetic routes. Unfortunately, metalation trials of these biopolymeric Schiff bases afford the corresponding Ag(I)/M(II) complexes (where M=Co, Pd). These designed architectures were structurally characterized and pharmacologically evaluated for their in vitro antimicrobial, against common bacterial and fungal pathogens, and anticancer activities against human colon carcinoma (HCT-116) cell line. In conclusion functionalization of chitosan with IL-Sal brushes coupled with metalation of formed ILCSBs were synergistically enhanced its antimicrobial and antitumor properties to a great extent. Noteworthy, Ag-ILCSB2 (IC50=9.13μg/mL) was ca. 5-fold more cytotoxic against HCT-116 cell line than ILCSB2 (IC50=43.30μg/mL). Copyright © 2016. Published by Elsevier Ltd.

Coordination behavior of new bis Schiff base ligand derived from 2-furan carboxaldehyde and propane-1,3-diamine. Spectroscopic, thermal, anticancer and antibacterial activity studies

NASA Astrophysics Data System (ADS)

Mohamed, Gehad G.; Zayed, Ehab M.; Hindy, Ahmed M. M.

2015-06-01

Novel bis Schiff base ligand, [N1,N3-bis(furan-2-ylmethylene)propane-1,3-diamine], was prepared by the condensation of furan-2-carboxaldehyde with propane-1,3-diamine. Its conformational changes on complexation with transition metal ions [Co(II), Ni(II), Cu(II), Mn(II), Cd(II), Zn(II) and Fe(III)] have been studied on the basis of elemental analysis, conductivity measurements, spectral (infrared, 1H NMR, electronic), magnetic and thermogravimetric studies. The conductance data of the complexes revealed their electrolytic nature suggesting them as 1:2 (for bivalent metal ions) and 1:3 (for Fe(III) ion) electrolytes. The complexes were found to have octahedral geometry based on magnetic moment and solid reflectance measurements. Thermal analysis data revealed the decomposition of the complexes in successive steps with the removal of anions, coordinated water and bis Schiff base ligand. The thermodynamic parameters were calculated using Coats-Redfern equation. The Anticancer screening studies were performed on human colorectal cancer (HCT), hepatic cancer (HepG2) and breast cancer (MCF-7) cell lines. The antimicrobial activity of all the compounds was studied against Gram negative (Escherichia coli and Proteus vulgaris) and Gram positive (Bacillus vulgaris and Staphylococcus pyogones) bacteria. It was observed that the coordination of metal ion has a pronounced effect on the microbial activities of the bis Schiff base ligand. All the metal complexes have shown higher antimicrobial effect than the free bis Schiff base ligand.

Role of FNA and Special Stains in Rapid Cytopathological Diagnosis of Pulmonary Nocardiosis.

PubMed

Sood, Ridhi; Tyagi, Ruchita; Selhi, Pavneet Kaur; Kaur, Gursheen; Kaur, Harpreet; Singh, Akashdeep

2018-01-01

Nocardia, a gram-positive aerobic bacillus of the Actinomycetales family, is a significant opportunistic pathogen in immunocompromised individuals. Clinical and radiological features of pulmonary nocardiosis are nonspecific and can be misdiagnosed as tuberculosis, pneumocystis, staphylococcal or fungal infections, or as malignancy. Aspiration cytology with special stains is a quick and effective approach for accurate diagnosis. We present 7 cases of pulmonary nocardiosis, admitted to the pathology department in a tertiary-care hospital in Punjab. Clinical findings, immune status, laboratory tests, chest radiographs, and computed tomography scans were reviewed. Cytologically, special stains like 1% Ziehl-Neelsen (ZN), 20% ZN, periodic acid-Schiff (PAS), Grocott methenamine silver (GMS), and reticulin stains were studied along with May-Grünwald Giemsa, Papanicolaou, and hematoxylin and eosin. All the patients were immunocompromised. The radiological changes were nonspecific. Cytomorphology showed acute and chronic inflammatory infiltrates with necrosis. None of the cases showed well-defined granulomas. GMS, modified 1% ZN and, Gordon and Sweet reticulin stains highlighted the delicate filamentous bacteria in all cases. PAS and 20% ZN stain for tuberculous bacilli were uniformly negative. FNAC can provide a quick and accurate diagnosis of nocardiosis and thereby facilitate timely medical management. © 2018 S. Karger AG, Basel.

The effect of fixatives and temperature on the quality of glycogen demonstration.

PubMed

Zakout, Yosef Mohamed Azzam; Salih, Magdi M; Ahmed, H G

2010-04-01

Glycogen is demonstrated in a number of lesions and is diagnostically significant, particularly in certain tumors. To stain glycogen accurately, it is essential to choose a suitable fixative, temperature and staining method. We used rabbit liver to assess these variables. Specimens were fixed in three fixatives at two temperatures: 10% formalin, neutral buffered formalin (NBF) and Bouin's solution at 37 and 4 degrees C. Seventy-two paraffin sections were prepared and stained with periodic acid-Schiff (PAS), hexamine (methenamine) silver and Best's carmine methods. Negative control sections using diastase digestion were used for all methods to confirm the presence of glycogen. For the PAS reaction, Bouin's fixative gave better results at both temperatures compared to the other fixatives. For hexamine (methenamine) silver, the quality of staining was improved for tissues fixed in both 10% formalin and NBF at 37 degrees C compared to Bouin's solution. Both 10% formalin and NBF at 4 degrees C gave better results than Bouin's solution. For Best's carmine, Bouin's solution gave the best results for tissues fixed at 4 degrees C. Fixation of tissues with NBF at 37 degrees C gave the best quality staining. We concluded that the quality of glycogen staining in paraffin sections is greatly affected by both the fixative and the temperature of fixation.

Effects of Unripe Musa Paradisiaca on the Histochemistry of the Testis and Testosterone Levels in Adult Albino Rats.

PubMed

Alabi, A S; Omotosho, G O; Tagoe, C N B; Akinola, O B; Enaibe, B U

2017-06-30

This study was aimed at determining the effects of the unripe fruit of Musa paradisiaca on the testis andtestosterone levels in male Wistar rats. The animals were grouped into three, comprising a control, and 2 treatment groupsadministered with different doses (500 mg/kg and 1000 mg/kg) daily of the fruit flour over 28 days. Histochemical evaluationof the testes was done using Haematoxylin and Eosin, Periodic acid Schiff's (PAS) and Feulgen staining techniques, whilethe serum and homogenised testicular tissue were evaluated for testosterone levels using Accu-Bind ELISA Kit. The testisof the treated groups showed more rapidly dividing cells and more population of sperm cells compared to the control group,and also showed more positivity for Feulgen staining and PAS reaction. Both serum and testicular testosterone levels werehowever reduced. Serum testosterone was significantly lowered in the animals given the low dose (0.67 ± 0.03 ng/ml),compared to those given high dose (0.85 ± 0.02 ng/ml) and the control animals (1.88 ± 0.15 ng/ml) (p < 0.05). Changes intesticular testosterone were not statistically significant. The study suggests that M. paradisiaca fruit has reproductiveenhancing potential when consumed moderately, but this benefit may not be related to testosterone levels.

Endocarditis Due to Rare and Fastidious Bacteria

PubMed Central

Brouqui, P.; Raoult, D.

2001-01-01

The etiologic diagnosis of infective endocarditis is easily made in the presence of continuous bacteremia with gram-positive cocci. However, the blood culture may contain a bacterium rarely associated with endocarditis, such as Lactobacillus spp., Klebsiella spp., or nontoxigenic Corynebacterium, Salmonella, Gemella, Campylobacter, Aeromonas, Yersinia, Nocardia, Pasteurella, Listeria, or Erysipelothrix spp., that requires further investigation to establish the relationship with endocarditis, or the blood culture may be uninformative despite a supportive clinical evaluation. In the latter case, the etiologic agents are either fastidious extracellular or intracellular bacteria. Fastidious extracellular bacteria such as Abiotrophia, HACEK group bacteria, Clostridium, Brucella, Legionella, Mycobacterium, and Bartonella spp. need supplemented media, prolonged incubation time, and special culture conditions. Intracellular bacteria such as Coxiella burnetii cannot be isolated routinely. The two most prevalent etiologic agents of culture-negative endocarditis are C. burnetti and Bartonella spp. Their diagnosis is usually carried out serologically. A systemic pathologic examination of excised heart valves including periodic acid-Schiff (PAS) staining and molecular methods has allowed the identification of Whipple's bacillus endocarditis. Pathologic examination of the valve using special staining, such as Warthin-Starry, Gimenez, and PAS, and broad-spectrum PCR should be performed systematically when no etiologic diagnosis is evident through routine laboratory evaluation. PMID:11148009

INS365 suppresses loss of corneal epithelial integrity by secretion of mucin-like glycoprotein in a rabbit short-term dry eye model.

PubMed

Fujihara, Tsutomu; Murakami, Tadahiro; Nagano, Takashi; Nakamura, Masatsugu; Nakata, Katsuhiko

2002-08-01

P2Y2 receptor agonists, like UTP and ATP, stimulate mucin secretion from goblet cells in vitro. Therefore, mucin stimulants could be good candidates for the treatment of dry eye syndrome because mucin increases the tear film stability and protects against desiccation of ocular surface. INS365 is a more stable P2Y2 receptor agonist than UTP. In the present study, we evaluated, in normal rabbit eyes, its effectiveness to release mucin from goblet cells and to protect the corneal damage induced by desiccation. For mucin secretion, impression cytology was performed following the instillation of INS365 solution or saline into the conjunctival sac. The specimens were stained with periodic acid and Schiff (PAS) reagent, and then the staining area was calculated using computer software. INS365 dose-dependently decreased the PAS staining area of conjunctival goblet cells from 2 to 15 min post-application. Furthermore, we utilized the rabbit short-term dry eye model to evaluate if INS365 eyedrops could protect against any of the damage produced by blockage of blinking with ocular speculum. INS365 significantly suppressed corneal damage at concentrations of more than 0.1% w/v. These results suggest that this P2Y2 agonist is a good candidate for the treatment of dry eye disease.

DNA Cleavage, Cytotoxic Activities, and Antimicrobial Studies of Ternary Copper(II) Complexes of Isoxazole Schiff Base and Heterocyclic Compounds

PubMed Central

Chityala, Vijay Kumar; Sathish Kumar, K.; Macha, Ramesh; Tigulla, Parthasarathy; Shivaraj

2014-01-01

Novel mixed ligand bivalent copper complexes [Cu. L. A. ClO 4] and [Cu. L. A] where “L” is Schiff bases, namely 2-((3,4-dimethylisoxazol-5-ylimino)methyl)-4-bromophenol (DMIIMBP)/2-((3,4-dimethylisoxazol-5-ylimino)methyl)-4-chlorophenol (DMIIMCP), and “A” is heterocyclic compound, such as 1,10-phenanthroline (phen)/2,21-bipyridyl (bipy)/8-hydroxyquinoline (oxine)/5-chloro-8-hydroxyquinoline (5-Cl-oxine), have been synthesized. These complexes have been characterized by IR, UV-Vis, ESR, elemental analysis, magnetic moments, TG, and DTA. On the basis of spectral studies and analytical data, five-coordinated square pyramidal/four-coordinated square planar geometry is assigned to all complexes. The ligands and their ternary complexes with Cu(II) have been screened for antimicrobial activity against bacteria and fungi by paper disc method. The antimicrobial studies of Schiff bases and their metal complexes showed significant activity and further it is observed that the metal complexes showed more activity than corresponding Schiff bases. In vitro antitumor activity of Cu(II) complexes was assayed against human cervical carcinoma (HeLa) cancer cells and it was observed that few complexes exhibit good antitumor activity on HeLa cell lines. The DNA cleavage studies have also been carried out on pBR 322 and it is observed that these Cu(II) complexes are capable of cleaving supercoiled plasmid DNA in the presence of H2O2 and UV light. PMID:24895493

Synthesis, characterization, nano-sized binuclear nickel complexes, DFT calculations and antibacterial evaluation of new macrocyclic Schiff base compounds

NASA Astrophysics Data System (ADS)

Parsaee, Zohreh; Mohammadi, Khosro

2017-06-01

Some new macrocyclic bridged dianilines tetradentate with N4coordination sphere Schiff base ligands and their nickel(II)complexes with general formula [{Ni2LCl4} where L = (C20H14N2X)2, X = SO2, O, CH2] have been synthesized. The compounds have been characterized by FT-IR, 1H and 13C NMR, mass spectroscopy, TGA, elemental analysis, molar conductivity and magnetic moment techniques. Scanning electron microscopy (SEM) shows nano-sized structures under 100 nm for nickel (II) complexes. NiO nanoparticle was achieved via the thermal decomposition method and analyzed by FT-IR, SEM and X-ray powder diffraction which indicates closeaccordance to standard pattern of NiO nanoparticle. All the Schiff bases and their complexes have been detected in vitro both for antibacterial activity against two gram-negative and two gram-positive bacteria. The nickel(II) complexes were found to be more active than the free macrocycle Schiff bases. In addition, computational studies of three ligands have been carried out at the DFT-B3LYP/6-31G+(d,p) level of theory on the spectroscopic properties, including IR, 1HNMR and 13CNMR spectroscopy. The correlation between the theoretical and the experimental vibrational frequencies, 1H NMR and 13C NMR of the ligands were 0.999, 0.930-0.973 and 0.917-0.995, respectively. Also, the energy gap was determined and by using HOMO and LUMO energy values, chemical hardness-softness, electronegativity and electrophilic index were calculated.

Synthesis and structure elucidation of a copper(II) Schiff-base complex: in vitro DNA binding, pBR322 plasmid cleavage and HSA binding studies.

PubMed

Tabassum, Sartaj; Ahmad, Musheer; Afzal, Mohd; Zaki, Mehvash; Bharadwaj, Parimal K

2014-11-01

New copper(II) complex with Schiff base ligand 4-[(2-Hydroxy-3-methoxy-benzylidene)-amino]-benzoic acid (H₂L) was synthesized and characterized by spectroscopic and analytical and single crystal X-ray diffraction studies which revealed that the complex 1 exist in a distorted octahedral environment. In vitro CT-DNA binding studies were performed by employing different biophysical technique which indicated that the 1 strongly binds to DNA in comparison to ligand via electrostatic binding mode. Complex 1 cleaves pBR322 DNA via hydrolytic pathway and recognizes minor groove of DNA double helix. The HSA binding results showed that ligand and complex 1 has ability to quench the fluorescence emission intensity of Trp 214 residue available in the subdomain IIA of HSA. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis, spectral, crystallography and thermal investigations of novel Schiff base complexes of manganese (III) derived from heterocyclic beta-diketone with aromatic and aliphatic diamine.

PubMed

Surati, Kiran R; Thaker, B T

2010-01-01

The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(1)), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(2)), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(3)) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(4)) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, (1)H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn(3)(mu(3)-O)(OAc)(6)(H(2)O)(3)].3H(2)O with ligands H(2)L(1), H(2)L(2), H(2)L(3) and H(2)L(4). All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion. Copyright 2009. Published by Elsevier B.V.

Synthesis, spectral, crystallography and thermal investigations of novel Schiff base complexes of manganese (III) derived from heterocyclic β-diketone with aromatic and aliphatic diamine

NASA Astrophysics Data System (ADS)

Surati, Kiran R.; Thaker, B. T.

2010-01-01

The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H 2L 1), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H 2L 2), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H 2L 3) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H 2L 4) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, 1H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn 3(μ 3-O)(OAc) 6(H 2O) 3]·3H 2O with ligands H 2L 1, H 2L 2, H 2L 3 and H 2L 4. All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion.

Synthesis, biological activity and molecular modeling study of new Schiff bases incorporated with indole moiety.

PubMed

Halawa, Ahmed H; El-Gilil, Shimaa Mohamed Abd; Bedair, Ahmed H; Shaaban, Mohamed; Frese, Marcel; Sewald, Norbert; Eliwa, Essam M; El-Agrody, Ahmed M

2017-10-26

A new series of heterocyclic Schiff bases 2-9 containing indole moiety were synthesized by facile and efficient condensation of indole-3/2/5-carboxaldehyde (1a/1b/1c) with different aromatic and heterocyclic primary amines using conventional and/or microwave irradiation methods. The structures of the obtained compounds were assigned by sophisticated spectroscopic and spectrometric techniques (1D-NMR, 2D-NMR and MS). The synthesized compounds were screened for their cytotoxicity and antibacterial activities. In vitro cytotoxicity screening revealed that compound 5 exhibited moderate activity against KB-3-1 cell line (IC50=57.7 μM) while 5-indolylimino derivative 7 indicated close to the activity (IC50=19.6 μM) in comparison with the positive control (+)-Griseofulvin (IC50=19.2 μM), while the tested compounds 5, 6b, 7 and 9 revealed good or moderate antibacterial activity. In addition, molecular docking study of Schiff bases 2-9 was performed by Molecular Operating Environment (MOE 2014.09) program on the matrix metalloproteinase-8 (MMP-8) (Protein Data Bank (PDB) ID: 1MNC) in an attempt to explore their mode of action as anticancer drugs.

New phthalimide-appended Schiff bases: Studies of DNA binding, molecular docking and antioxidant activities.

PubMed

Nayab, Pattan Sirajuddin; Akrema; Ansari, Istikhar A; Shahid, Mohammad; Rahisuddin

2017-08-01

Herein, we investigated new phthalimide-based Schiff base molecules as promising DNA-binding and free radical scavenging agents. Physicochemical properties of these molecules were demonstrated on the basis of elemental analysis, ultraviolet-visible (UV-Vis), infra-red (IR), 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy. All spectral data are agreed well with the proposed Schiff base framework. The DNA-binding potential of synthesized compounds were investigated by means of UV-visible, fluorescence, iodide quenching, circular dichroism, viscosity and thermal denaturation studies. The intrinsic binding constants (K b ) were calculated from absorption studies were found to be 1.1 × 10 4 and 1.0 × 10 4  M -1 for compounds 2a and 2b suggesting that compound 2a binding abilities with DNA were stronger than the compound 2b. Our studies showed that the presented compounds interact with DNA through groove binding. Molecular docking studies were carried out to predict the binding between Ct-DNA and test compounds. Interestingly, in silico predictions were corroborated with in vitro DNA-binding conclusions. Furthermore, the title compounds displayed remarkable antioxidant activity compared with reference standard. Copyright © 2016 John Wiley & Sons, Ltd.

[Effect of the folic acid and vitamin B2 on the diabetes mellitus rats with diabetic nephropathy].

PubMed

Xu, Rongxian; Fan, Yanfeng; Xiang, Jianjun; Zhan, Meirong

2012-11-01

To explore the relationship among the folic acid, vitamin B12 and diabetic nephropathy and to discuss the mechanism of the diabetic microangiopathy. We selected 80 SD rats, and then divided them into 2 groups randomly. Those were the control group and the model groups. During the process of this study, the control group was fed with the normal animal feeds; the model groups were fed with the high calorie diets for 10 weeks. At the end of the tenth week, the rats of the model group were induced to diabetes mellitus by intraperitoneal injection with streptozocin 30mg/kg, and then we divided the diabetes mellitus rats into 4 groups which measured the levels of the blood fat (total cholesterin, triglyceride), Fins, FBG, SOD, MDA, GSH-Px. Results (1) Through feeding the rats with the special feeds for a long time, and then injecting with streptozocin can make them develop to be the diabetes mellitus. The model groups' levels of the triglyceride, the cholesterin and the random blood glucose were (1.07 +/- 0.27), (2.29 +/- 0.42), (21.12 +/- 4.21) mmol/L, respectively, those were significantly higher than the control group's levels which were (1.11 +/- 0.20), (0.68 +/- 0.11), (5.73 +/- 0.26) mmol/L (P < 0.05). (2) After given different interference, for the group of the diabetes mellitus rats that without fed with vitamin B12 and folic acid, the degree of the pathological change of kidney tissue was the most serious through the method of periodic acid-Schiff' s staining (PAS), and the level of the MDA was also highest (P < 0.05), the level of the GSH-Px was lowest (P < 0.05) during the all groups. What' s more, both of the folic acid and the vitamin B12 could reduce the increase of the 24hours urinary albumin, especially using the folic acid and the vitamin B12 together. Using the special feeds to feed the SD rats for ten weeks and then inject STZ (30 mg/kg) from abdominal cavity can make them develop to be the diabetes mellitus. The supplement with folic acid and vitamin

Localization and characterization of acharan sulfate in the body of the giant African snail Achatina fulica.

PubMed

Jeong, J; Toida, T; Muneta, Y; Kosiishi, I; Imanari, T; Linhardt, R J; Choi, H S; Wu, S J; Kim, Y S

2001-12-01

Acharan sulfate is a glycosaminoglycan (GAG), having the structure -->4)-2-acetamido-2-deoxy-alpha-D-glucopyranose(1-->4)-2-sulfo-alpha-L-idopyranosyluronic acid (1-->, isolated from the body of the giant African snail Achatina fulica. This GAG represents 3-5% of the dry weight of this snail's soft body tissues. Frozen sections and polyester wax sections of the snail's body were stained by Alcian blue-periodic acid-Schiff's reagent (PAS) to localize acharan sulfate. Alcian blue staining indicated that GAG was mainly secreted into the outer surface of the body from internal granules. A highly mucous material was collected and treated and the acharan sulfate was recovered by ethanol and cetyl pyridinium chloride precipitation. Crude acharan sulfate was purified by DEAE-Sephacel ion-exchange chromatography. Depolymerization of intact mucus and purified acharan sulfate fractions by heparin lyase II (heparitinase I) from Flavobacterium heparinum produced an unsaturated disaccharide as a major product, establishing the repeating unit of acharan sulfate. These results demonstrate that mucus in the granule and secreted to the outside of the body is composed entirely of acharan sulfate.

Lipoid proteinosis: A case with distinct histopathological and radiological findings.

PubMed

Brar, Balvinder Kaur; Jain, Sarina; Brar, Sukhmani Kaur

2017-10-01

Lipoid proteinosis is a rare inherited genodermatosis characterized by hyaline deposits in various tissues. Clinically, it manifests with cutaneous as well as extracutaneous features. Periodic acid-Schiff (PAS)-reactive hyaline deposits in the upper dermis, with localization around blood vessels and eccrine sweat glands, in particular, is the histopathological hallmark finding. On brain imaging, bilateral symmetrical temporal lobe calcifications are considered to be pathognomonic of this disorder. We report a case of lipoid proteinosis in which hyaline deposits were present in the papillary and reticular dermis, without being seen at the periphery of eccrine sweat glands, along with dystrophic calcification. Magnetic resonance imaging (MRI) of brain revealed hydrocephalus, subependymal heterotropia and absent splenium of corpus callosum with no evidence of temporal lobe calcification. Thus, our case highlights the inherent diverse nature of lipoid proteinosis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lafora's-like disease in a fennec fox (Vulpes zerda).

PubMed

Honnold, Shelley P; Schulman, F Yvonne; Bauman, Karen; Nelson, Kevin

2010-09-01

A 6-yr-old captive-born female fennec fox (Vulpes zerda) had a history of multiple seizures and was treated with diazepam and phenobarbital therapy. Despite medical treatment, the seizures continued. They were intermittent and progressive, resulting in neurologic deficits and death of the animal within 6 mo of onset of the clinical signs. At necropsy, the animal was in good nutritional condition, and no gross lesions were noted in the brain. Histologically, amphophilic to basophilic, periodic acid-Schiff (PAS) positive, diastase-resistant inclusions were present in the brain, heart, and liver. Ultrastructurally, the inclusions were variably electron dense, fibrillary to occasionally granular, and non-membrane bound. The clinical, histologic, and ultrastructural findings were consistent with Lafora's disease, which in humans is a rare, fatal, autosomal recessive hereditary neurometabolic disorder characterized by progressive myoclonic epilepsy. This is the first report of Lafora's-like disease in a fennec fox.

Variation in Venoms of Polybia Paulista Von Ihering and Polybia Occidentalis Olivier (Hymenoptera: Vespidae), Assessed by the FTIR-PAS Technique.

PubMed

Mendonça, A; Paula, M C; Fernandes, W D; Andrade, L H C; Lima, S M; Antonialli-Junior, W F

2017-02-01

Wasps are able to synthesize toxic compounds known as venoms, which form a part of a mechanism to overcome prey and also to defend their colonies. Study of the compounds that constitute these substances is essential in order to understand how this defense mechanism evolved, since there is evidence that the venoms can vary both intra- and interspecifically. Some studies have used liquid and gas chromatography as a reliable technique to analyze these compounds. However, the use of Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) to analyze the variations in venom's chemical profile has been proposed recently. This study evaluated whether the FTIR-PAS technique is effective for assessing the role of environmental factors on intra- and interspecific differences in the venom of the wasps Polybia paulista Von Ihering and Polybia occidentalis Olivier by FTIR-PAS. The colonies were collected in three municipalities of Mato Grosso do Sul, Brazil, in different types of environments. The results showed that the venoms of P. paulista and P. occidentalis differed significantly in profile. In addition, the intraspecific differences in the venom's chemical profile of P. paulista are related to the type of environment where they nested, regardless of the geographical distance between the nests. The FTIR-PAS technique proved to be reliable and effective to evaluate the variations in the venom's chemical profile in social wasps.

Preparation of new Schiff bases derived from beta-enaminonitriles and hetarylcarboxaldehydes. Anti-inflammatory and ulcerogenic activities.

PubMed

Atta, S M; Ameen, A

1993-12-01

Schiff bases 3a-j were prepared by reacting the beta-enaminonitriles (1a,b) with the appropriate hetarylcarboxaldehyde, in boiling ethanol. Structural elucidations for the new compounds (3a-j) were based upon compatible analytical and spectroscopic results. Compounds 1a, 1b, 3a, 3c, 3d and 3i were tested for their anti-inflammatory and ulcerogenic activities.

The PAS domains of the major sporulation kinase in Bacillus subtilis play a role in tetramer formation that is essential for the autokinase activity.

PubMed

Kiehler, Brittany; Haggett, Lindsey; Fujita, Masaya

2017-08-01

Sporulation in Bacillus subtilis is induced upon starvation. In a widely accepted model, an N-terminal "sensor" domain of the major sporulation kinase KinA recognizes a hypothetical starvation signal(s) and autophosphorylates a histidine residue to activate the master regulator Spo0A via a multicomponent phosphorelay. However, to date no confirmed signal has been found. Here, we demonstrated that PAS-A, the most N-terminal of the three PAS domains (PAS-ABC), is dispensable for the activity, contrary to a previous report. Our data indicated that the autokinase activity is dependent on the formation of a functional tetramer, which is mediated by, at least, PAS-B and PAS-C. Additionally, we ruled out the previously proposed notion that NAD + /NADH ratio controls KinA activity through the PAS-A domain by demonstrating that the cofactors show no effects on the kinase activity in vitro. In support of these data, we found that the cofactors exist in approximately 1000-fold excess of KinA in the cell and the cofactors' ratio does not change significantly during growth and sporulation, suggesting that changes in the cofactor ratio might not play a role in controlling KinA activity. These data may refute the widely-held belief that the activity of KinA is regulated in response to an unknown starvation signal(s). © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Tropheryma whipplei Infection (Whipple Disease) in the USA.

PubMed

Hujoel, Isabel A; Johnson, David H; Lebwohl, Benjamin; Leffler, Daniel; Kupfer, Sonia; Wu, Tsung-Teh; Murray, Joseph A; Rubio-Tapia, Alberto

2018-03-23

Whipple disease (WD) is an infection caused by the bacterium Tropheryma whipplei (TW). Few cases have been reported in the USA. To report on the demographics, clinical manifestations, diagnostic findings, treatment, and outcomes of TW infection. Cases of TW infection diagnosed from 1995 to 2010 were identified in three US referral centers and from 1995 to 2015 in one. Definite classic WD was defined by positive periodic acid-Schiff (PAS) staining and probable WD by specific positive TW polymerase chain reaction (PCR) of intestinal specimens. Localized infections were defined by a positive TW PCR result from samples of other tissues/body fluids. Among the 33 cases of TW infections, 27 (82%) were male. Median age at diagnosis was 53 years (range 11-75). Diagnosis was supported by a positive TW PCR in 29 (88%) and/or a positive PAS in 16 (48%) patients. Classic WD was the most frequent presentation (n = 18, 55%), with 14 definite and 4 probable cases. Localized infections (n = 15, 45%) affected the central nervous system (n = 7), joints (n = 4), heart (n = 2), eye (n = 1), and skeletal muscle (n = 1). Blood PCR was negative in 9 of 17 (53%) cases at diagnosis. Ceftriaxone intravenously followed by trimethoprim and sulfamethoxazole orally was the most common regimen (n = 23, 70%). Antibiotic therapy resulted in clinical response in 24 (73%). TW infection can present as intestinal or localized disease. Negative small bowel PAS and PCR do not exclude the diagnosis of TW infection, and blood PCR is insensitive for active infection.

Synthesis, spectral, thermal and biological studies of mixed ligand complexes with newly prepared Schiff base and 1,10-phenanthroline ligands

NASA Astrophysics Data System (ADS)

Abd El-Halim, Hanan F.; Mohamed, Gehad G.; Khalil, Eman A. M.

2017-10-01

A series of mixed ligand complexes were prepared from the Schiff base (L1) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. The Schiff base ligand and its mixed ligand chelates were characterized based on elemental analysis, IR, 1H NMR, thermal analysis, UV-Visible, mass, molar conductance, magnetic moment. X-ray diffraction, solid reflectance and ESR also have been studied. The mixed ligand complexes were found to have the formulae of [M(L1) (1,10-phen)]Clm.nH2O (M = Cr(III) and Fe(III) (m = 3) (n = 0); M = Mn(II), Cu(II) and Cd(II) (m = 2) (n = 0); and M = Co(II) (m = 2) (n = 1), Ni(II) (m = 2) (n = 2) and Zn(II) (m = 2) (n = 3)) and that the geometrical structure of the complexes were octahedral. The parameters of thermodynamic using Coats-Redfern and Horowitz-Metzger equations were calculated. The synthesized Schiff base ligand, 1,10-phenanthroline ligand and Their mixed ligand complexes were also investigated for their antibacterial and antifungal activity against bacterial species (Gram-Ve bacteria: Pseudomonas aeruginosa and Escherichia coli) and (Gram + Ve bacteria: Bacillus subtilis and Streptococcus pneumonia) and fungi (Aspergillus fumigates and Candida albicans). The anticancer activity of the new compounds had been tested against breast (MFC7) and colon (HCT-116) cell lines. The results showed high activity for the synthesized compounds.

Synthesis, spectroscopic characterization and antimicrobial studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes with Schiff bases derived from 5-bromo-salicylaldehyde

NASA Astrophysics Data System (ADS)

Kursunlu, Ahmed Nuri; Guler, Ersin; Sevgi, Fatih; Ozkalp, Birol

2013-09-01

In this study, the new Schiff base ligands derived from condensation of amine and 5-bromo-salicylaldehyde were characterized. All compounds, the Schiff bases and the metal complexes, were characterized by elemental analyzes, FT-IR, 1H NMR, 13C NMR and magnetic susceptibility measurements. The synthesized ligands, along with their metal (II) complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis) and four Gram-positive (Streptococcus pyogones, Bacillus cereus, Staphylococcus aureus and Methicillin-resistant S. aureus) bacterial strains by using disc diffusion and broth microdilution techniques.

Biologically active and thermally stable polymeric Schiff base and its metal polychelates: Their synthesis and spectral aspects

NASA Astrophysics Data System (ADS)

Rasool, Raza; Hasnain, Sumaiya

2015-09-01

New metal polychelates of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) obtained by the interaction of metal acetates with polymeric Schiff base containing formaldehyde and piperazine, have been investigated. Structural and spectroscopic properties have been evaluated by elemental analysis, FT-IR and 1H-NMR. Geometry of the chelated polymers was confirmed by magnetic susceptibility measurements, UV-Visible spectroscopy and Electron Spin Resonance. The molecular weight of the polymer was determined by gel permeation chromatography (GPC). Thermogravimetric analysis indicated that metal polychelates were more thermally stable than their corresponding ligand. All compounds were screened for their antimicrobial activities against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, (bacteria) and Candida albicans, Microsporum canis, Cryptococcus neoformans (fungi) by agar well diffusion method. Interestingly, the polymeric Schiff base was found to be antimicrobial in nature but less effective as compared to the metal polychelates. On the basis of thermal and antimicrobial behavior, these polymers hold potential applications as thermally resistant antimicrobial and antifouling coating materials as well as antimicrobial packaging materials.

Whipple’s disease: misdiagnosed as sarcoidosis with further tricuspid valve endocarditis and pulmonary embolism – a case report

PubMed Central

Berent, Robert; Auer, Johann; Lassnig, Elisabeth; von Duvillard, Serge P; Crouse, Stephen F; Tuppy, Herwig; Eber, Bernd

2009-01-01

GH Whipple described a 36-year-old physician in 1907 with gradual loss of weight and strength, stools consisting chiefly of neutral fat and fatty acids, indefinite abdominal signs and a peculiar multiple arthritis. The patient died of this progressive illness. Whipple called it intestinal lipodystrophy since he observed accumulation of large masses of neutral fats and fatty acids in the lymph spaces. It was renamed Whipple’s disease in 1949. An infectious aetiology was suspected as early as Whipple’s initial report. However, successful treatment with antibiotics was not reported until 1952, which resulted in dramatic clinical responses. The cause is now known to be Tropheryma whipplei. Light and electron microscopy of infected tissue identified a gram-positive, non-acid-fast, periodic acid-Schiff (PAS) positive bacillus with a characteristic trilamellar plasma membrane resembling that of gram-negative bacteria. Whipple’s disease is extremely rare. It is a systemic infectious disorder affecting mostly middle-aged white men. The clinical presentation is often non-specific, which may make its diagnosis difficult. The four cardinal clinical manifestations are arthralgias, weight loss, diarrhoea and abdominal pain. The frequently vague articular symptoms can precede the diagnosis of Whipple’s disease by an average of 6–8 years. Lymph nodes and other tissues may present diagnostic problems, since the changes in routinely stained sections may mimic those of sarcoidosis. The detection of PAS-positive histiocytes in the small intestine remains the mainstay of the diagnosis, although Whipple’s disease without gastrointestinal involvement is described. We illustrate a case in which, retrospectively, the clinical presentation would have been typical for Whipple’s disease. However, the clinical presentation and the histological examinations of lymph nodes, liver biopsies and ascites initially were misinterpreted as sarcoidosis with consecutive immunosuppressive

Effect of feeding fresh forage and marine algae on the fatty acid composition and oxidation of milk and butter.

PubMed

Glover, K E; Budge, S; Rose, M; Rupasinghe, H P V; Maclaren, L; Green-Johnson, J; Fredeen, A H

2012-06-01

This study evaluated the effects of feeding fresh forage either as pasture plus a concentrate (PAS) or as a silage-based total mixed ration (TMR), combined with either a ruminally inert lipid supplement high in saturated fatty acids (-) or a ruminally protected microalgae containing 22 g of docosahexaenoic acid (DHA)/100 g of fatty acids (+) on the fatty acid (FA) composition and oxidation of milk and butter. For the 8 mid-lactation Holstein cows in this study, milk yield was not significantly affected by treatment, averaging 32.3 ± 1.28 kg/d. Milk fat content was higher for PAS⁻, averaging 5.05 compared with 4.10 ± 0.17% for the mean of other treatments, and was significantly depressed with microalgae supplementation (3.97 vs. 4.69 ± 0.17%). The saturated fatty acid level in the milk of cows fed TMR⁻ was significantly higher than that of the other treatments (66.9 vs. 61.2 g/100 g of FA). The level of monounsaturated FA was lowered by feeding TMR⁻ (27.4 vs. 32.0 g/100 g of FA), whereas levels of polyunsaturated FA were elevated by feeding PAS+ compared with the mean of the other treatments (6.54 vs. 5.07 g/100 g of FA). Feeding the rumen-protected microalgae increased the DHA content of milk more than 4-fold (0.06 to 0.26 g/100g of FA) with the PAS treatment. The conjugated linoleic acid content of milk was highest for PAS+ compared with the other treatments (4.18 vs. 3.41 g/100g of FA). In general, the fatty acid composition of butter followed that of milk. Overall, feeding the TMR supplemented with the rumen-protected microalgae increased the levels of volatile products of oxidation in milk and butter. No effect of forage type or microalgae supplementation was observed on the oxidative stability or antioxidant capacity of milk, although the oxidative stability of butter exposed to UV was reduced with microalgae supplementation, particularly with TMR, as assessed by using the ferric reducing ability of plasma assay. Copyright © 2012 American Dairy

Deciphering Dimerization Modes of PAS Domains: Computational and Experimental Analyses of the AhR:ARNT Complex Reveal New Insights Into the Mechanisms of AhR Transformation

PubMed Central

Corrada, Dario; Soshilov, Anatoly A.; Denison, Michael S.

2016-01-01

The Aryl hydrocarbon Receptor (AhR) is a transcription factor that mediates the biochemical response to xenobiotics and the toxic effects of a number of environmental contaminants, including dioxins. Recently, endogenous regulatory roles for the AhR in normal physiology and development have also been reported, thus extending the interest in understanding its molecular mechanisms of activation. Since dimerization with the AhR Nuclear Translocator (ARNT) protein, occurring through the Helix-Loop-Helix (HLH) and PER-ARNT-SIM (PAS) domains, is needed to convert the AhR into its transcriptionally active form, deciphering the AhR:ARNT dimerization mode would provide insights into the mechanisms of AhR transformation. Here we present homology models of the murine AhR:ARNT PAS domain dimer developed using recently available X-ray structures of other bHLH-PAS protein dimers. Due to the different reciprocal orientation and interaction surfaces in the different template dimers, two alternative models were developed for both the PAS-A and PAS-B dimers and they were characterized by combining a number of computational evaluations. Both well-established hot spot prediction methods and new approaches to analyze individual residue and residue-pairwise contributions to the MM-GBSA binding free energies were adopted to predict residues critical for dimer stabilization. On this basis, a mutagenesis strategy for both the murine AhR and ARNT proteins was designed and ligand-dependent DNA binding ability of the AhR:ARNT heterodimer mutants was evaluated. While functional analysis disfavored the HIF2α:ARNT heterodimer-based PAS-B model, most mutants derived from the CLOCK:BMAL1-based AhR:ARNT dimer models of both the PAS-A and the PAS-B dramatically decreased the levels of DNA binding, suggesting this latter model as the most suitable for describing AhR:ARNT dimerization. These novel results open new research directions focused at elucidating basic molecular mechanisms underlying the

Deciphering Dimerization Modes of PAS Domains: Computational and Experimental Analyses of the AhR:ARNT Complex Reveal New Insights Into the Mechanisms of AhR Transformation.

PubMed

Corrada, Dario; Soshilov, Anatoly A; Denison, Michael S; Bonati, Laura

2016-06-01

The Aryl hydrocarbon Receptor (AhR) is a transcription factor that mediates the biochemical response to xenobiotics and the toxic effects of a number of environmental contaminants, including dioxins. Recently, endogenous regulatory roles for the AhR in normal physiology and development have also been reported, thus extending the interest in understanding its molecular mechanisms of activation. Since dimerization with the AhR Nuclear Translocator (ARNT) protein, occurring through the Helix-Loop-Helix (HLH) and PER-ARNT-SIM (PAS) domains, is needed to convert the AhR into its transcriptionally active form, deciphering the AhR:ARNT dimerization mode would provide insights into the mechanisms of AhR transformation. Here we present homology models of the murine AhR:ARNT PAS domain dimer developed using recently available X-ray structures of other bHLH-PAS protein dimers. Due to the different reciprocal orientation and interaction surfaces in the different template dimers, two alternative models were developed for both the PAS-A and PAS-B dimers and they were characterized by combining a number of computational evaluations. Both well-established hot spot prediction methods and new approaches to analyze individual residue and residue-pairwise contributions to the MM-GBSA binding free energies were adopted to predict residues critical for dimer stabilization. On this basis, a mutagenesis strategy for both the murine AhR and ARNT proteins was designed and ligand-dependent DNA binding ability of the AhR:ARNT heterodimer mutants was evaluated. While functional analysis disfavored the HIF2α:ARNT heterodimer-based PAS-B model, most mutants derived from the CLOCK:BMAL1-based AhR:ARNT dimer models of both the PAS-A and the PAS-B dramatically decreased the levels of DNA binding, suggesting this latter model as the most suitable for describing AhR:ARNT dimerization. These novel results open new research directions focused at elucidating basic molecular mechanisms underlying the

A novel coumarin Schiff-base as a Ni(II) ion colorimetric sensor

NASA Astrophysics Data System (ADS)

Wang, Lingyun; Ye, Decheng; Cao, Derong

2012-05-01

A novel coumarin Schiff base compound (L) prepared from 7-diethylaminocoumarin-3-aldehyde and 3-amino-7-hydroxycoumarin was synthesized and evaluated as a chemoselective Ni2+ sensor. Addition of Ni2+ to CH3CN solution of L resulted in a rapid color change from yellow to red together with a large red shift from 465 to 516 nm. Moreover, other common alkali-, alkaline earth-, transition- and rare earth metal ions induced no or minimal spectral changes. Experimental results indicated that L could be used as a potential Ni2+ colorimetric and naked-eye chemosensor in CH3CN solution.

Diorganotin(IV) complexes of biologically potent 4(3H)-quinazolinone derived Schiff bases: synthesis, spectroscopic characterization, DNA interaction studies and antimicrobial activity.

PubMed

Prasad, Kollur Shiva; Kumar, Linganna Shiva; Chandan, Shivamallu; Jayalakshmi, Basvegowda; Revanasiddappa, Hosakere D

2011-10-15

Four Schiff base ligands and their corresponding organotin(IV) complexes have been synthesized and characterized by elemental analyses, IR, (1)H NMR, MS and thermal studies. The Schiff bases are obtained by the condensation of 3-amino-2-methyl-4(3H)-quinazolinone with different substituted aldehydes. The elemental analysis data suggest the stoichiometry to be 1:1 ratio formation. Infrared spectral data agreed with the coordination to the central metal ion through imine nitrogen, lactam oxygen and deprotonated phenolic oxygen atoms. All the synthesized compounds have been evaluated for antimicrobial activity against selected species of microorganisms. In addition, DNA binding/cleavage capacity of the compounds was analyzed by absorption spectroscopy, viscosity measurements and gel electrophoresis methods. Copyright © 2011 Elsevier B.V. All rights reserved.

Schiff Base modified on CPE electrode and PCB gold electrode for selective determination of silver ion

NASA Astrophysics Data System (ADS)

Leepheng, Piyawan; Suramitr, Songwut; Phromyothin, Darinee

2017-09-01

The schiff base was synthesized by 2,5-thiophenedicarboxaldehyde and 1,2,4-thiadiazole-3,5-diamine with condensation method. There was modified on carbon paste electrode (CPE) and Printed circuit board (PCB) gold electrode for determination silver ion. The schiff base modified electrodes was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), respectively. The electrochemical study was reported by cyclic voltammetry method and impedance spectroscopy using modified electrode as working electrode, platinum wire and Ag/AgCl as counter electrode and reference electrode, respectively. The modified electrodes have suitable detection for Ag+. The determination of silver ions using the modified electrodes depended linearly on Ag+ concentration in the range 1×10-10 M to 1×10-7 M, with cyclic voltammetry sensitivity were 2.51×108 μAM-1 and 1.88×108 μAM-1 for PCB gold electrode and CPE electrode, respectively, limits of detection were 5.33×10-9 M and 1.99×10-8 M for PCB gold electrode and CPE electrode, respectively. The modified electrodes have high accuracy, inexpensive and can applied to detection Ag+ in real samples.

Sialomucins are characteristically O-acylated in poorly differentiated and colloid prostatic adenocarcinomas.

PubMed

Sáez, C; Japón, M A; Conde, A F; Poveda, M A; Luna-Moré, S; Segura, D I

1998-12-01

Mucinous glycoproteins are secreted by prostatic adenocarcinomas and might play important roles in tumor invasion and metastasis. Their histochemical properties on routine biopsy specimens have not been fully characterized. We present a histochemical study of mucin in 21 prostatic adenocarcinomas, with particular focus on the demonstration of different types of sialomucins. We applied the following histochemical techniques to routinely processed, formalin-fixed, paraffin-embedded tissue sections: Alcian blue (pH 2.5) and periodic acid-Schiff to reveal both acidic and neutral mucins; high iron diamine and Alcian blue (pH 2.5) to show sulfated and acidic nonsulfated mucosubstances simultaneously; periodic acid borohydride, potassium hydroxide, and periodic acid-Schiff to demonstrate O-acylated sialic acids; periodic acid thionine-Schiff, potassium hydroxide, and periodic acid-Schiff to differentiate pre-existing glycols from those revealed after saponification procedures; and periodic acid borohydride and periodic acid-Schiff to show C9-O-acylated sialic acid. These techniques are useful tools for demonstrating neutral and acidic (sialo- and sulfo-) mucins and di(C8,C9- or C7,C9-)-O-acylated, tri(C7,C8,C9-)-O-acylated and mono(C9)-O-acylated sialomucins. Most prostatic adenocarcinomas showed acidic mucins, with sialomucins predominating over sulfomucins. Well-differentiated and moderately differentiated noncolloid tumors had non-O-acylated sialomucins. Poorly differentiated tumors contained mono-O-acylated (C9) sialomucins, and colloid-type tumors secreted mono-, di-, and tri-O-acylated sialoglycoproteins. Acidic mucins, mainly sialomucins, constitute the major secretory component in prostatic adenocarcinomas, and our results show that the O-acylation of these sialoglycoproteins inversely correlates with tumor differentiation. Well-differentiated and moderately differentiated tumors are not O-acylated, whereas the poorly differentiated ones characteristically have O

A novel source of MeV positron bunches driven by energetic protons for PAS application

NASA Astrophysics Data System (ADS)

Tan, Zongquan; Xu, Wenzhen; Liu, Yanfen; Xiao, Ran; Kong, Wei; Ye, Bangjiao

2014-11-01

This paper proposes a novel methodology of MeV positrons generation for PAS application. Feasibility of this proposal analyzed by G4Beamline and Transport have shown reasonable success. Using 2 Hz, 1.6 GeV, 100 ns and 1.5 μC/bunch proton bunches for bombarding a graphite target, about 100 ns e+ bunches are generated. Quasi-monochromatic positrons in the range of 1-10 MeV included in these bunches have a flux of >107/s, peak brightness of 1014/s. A magnetic-confinement beamline is utilized to transport the positrons and a "Fast Beam Chopper" is unprecedentedly extended to chop those relativistic bunches. The positron beam can be finally characterized by the energy range of 1-10 MeV and bunch width from one hundred ps up to 1 ns. Such ultrashort bunches can be useful in tomography-type positron annihilation spectroscopy (PAS) as well as other applications.

Synthesis, spectroscopic, DFT studies and biological activity of some ruthenium carbonyl derivatives of bis-(salicylaldehyde)phenylenediimine Schiff base ligand

NASA Astrophysics Data System (ADS)

Ramadan, Ramadan M.; Abu Al-Nasr, Ahmad K.; Ali, Omayma A. M.

2018-06-01

Bis-(salicylaldehyde)phenylenediimine Schiff base (H2salphen) reacted oxidatively with the triruthenium dodecacarbonyl complex, [Ru3(CO)12] to give the dicarbonyl derivative [Ru(CO)2(salphen)], 1. In presence of a secondary ligand L (L = pyridine, triphenyl phosphine, 2-aminobenzimidazole or thiourea), the monocarbonyl derivatives [Ru(CO)(salphen)L], 2-5, were isolated. When the bipyridine (bpy) ligand was used as a secondary ligand, the dicarbonyl complex [Ru(CO)2(Hsalphen)(bpy)], 6, was obtained. In complexes 1-5, the Schiff base ligand acted as a tetradentate, while it coordinated as a bidentate in complex 6. The structure and stoichiometry of the complexes were investigated by the conventional analytical and spectroscopic techniques, which revealed that they have several structural arrangements. The structures of ligand and complexes were verified by theoretical calculations based on accurate DFT approximations. The relative reactivities were estimated using chemical descriptors analysis. Biological activities of the complexes against the Escherchia coli and Staphylococcus aureus bacteria were screened.

Ultrasensitive and highly selective detection of Cu2 + ions based on a new carbazole-Schiff

NASA Astrophysics Data System (ADS)

Yin, Jun; Bing, Qijing; Wang, Lin; Wang, Guang

2018-01-01

A new chemosensor for Cu2 + based on Schiff base with high sensitivity and selectivity was designed and synthesized. The fluorescence intensity of the chemosensor in CH3CN solution was enhanced 160-fold after the addition of 10 equiv. Cu2 + over other metal ions. In addition, it also facilitates colorimetric detection for Cu2 + in CH3CN solution. The chemosensor displayed low detection limit and fast response time to Cu2 +.

Synthesis of Two Coumarin-Derived Schiff Bases and Investigation of theirs Selectivity for Zn2.

PubMed

Fan, Long

2017-07-01

In this study, the coumarin-derived schiff bases (HL 1 and HL 2 ) have been designed and synthesized. Upon the addition of Zn 2+ , both of them show significant fluorescence enhancement owing to inhibits PET and ESIPT process respectively. However, the receptor HL 2 response toward Cd 2+ , Mg 2+ , Ba 2+ , Ca 2+ besides Zn 2+ and exhibits fluorescence enhancement but not enough to detection of the concentration levels of Zn 2+ .

Effects of stearic acid and gamma irradiation, alone and in combination, on pasting properties of high amylose maize starch.

PubMed

Ocloo, Fidelis C K; Minnaar, Amanda; Emmambux, Naushad M

2016-01-01

The effects of stearic acid and gamma irradiation on pasting properties of high amylose maize starch (HAMS) were studied. Stearic acid (0%, 1.5%, and 5%) was added to HAMS, and then irradiated at 0, 30, and 60 kGy before pasting. Stearic acid increased the paste viscosity of un-irradiated HAMS from 420 mPas to 557 and 652 mPas for 1.5% and 5% stearic acid, respectively. This observation related well with the formation of type II amylose-lipid complexes, with melting temperatures of about 100-120 °C. Gamma irradiation (30 and 6 0kGy) reduced pasting viscosity of HAMS. Pasting of gamma irradiated HAMS resulted in the formation of type I amylose-lipid complexes, with melting temperatures and enthalpies ranging from 82 to 102 °C and 0.22 to 1.85 J/g, respectively. Stearic acid addition followed by irradiation creates means of producing different types of amylose-lipid complexes from HAMS for industrial utilization. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ultrasonic promoted synthesis of novel s-triazine-Schiff base derivatives; molecular structure, spectroscopic studies and their preliminary anti-proliferative activities

NASA Astrophysics Data System (ADS)

El-Faham, Ayman; Soliman, Saied M.; Ghabbour, Hazem A.; Elnakady, Yasser A.; Mohaya, Talal A.; Siddiqui, Mohammed R. H.; Albericio, Fernando

2016-12-01

Novel series of s-triazine-Schiff base derivatives were synthesized employing ultrasonic irradiation and characterized by NMR (1H and 13C), FT-IR, and elemental analysis. The use of ultrasonic irradiation has allowed the preparation of the target products with better yields in shorter reaction time and excellent purities compared to the conventional heating. X-ray single crystal diffraction experiments verified the molecular structure of four from the new prepared s-triaizne-Schiff base derivatives. The molecular structures of the studied compounds are computerized using DFT/B3LYP method. The effects of substituent at the triazine and phenyl ring on the electronic and spectroscopic properties of the studied compounds were also investigated. The natural atomic charges showed that pipridino-s-triazine derivatives are richer in electrons than those having morpholino derivatives. The anti-proliferative effects for the prepared compounds were tested against three different cancer cell lines.

DNA incision evaluation, binding investigation and biocidal screening of Cu(II), Ni(II) and Co(II) complexes with isoxazole Schiff bases.

PubMed

Ganji, Nirmala; Chityala, Vijay Kumar; Marri, Pradeep Kumar; Aveli, Rambabu; Narendrula, Vamsikrishna; Daravath, Sreenu; Shivaraj

2017-10-01

Two new series of binary metal complexes [M(L 1 ) 2 ] and [M(L 2 ) 2 ] where, M=Cu(II), Ni(II) & Co(II) and L 1 =4-((3,4-dimethylisoxazol-5-ylimino)methyl)benzene-1,3-diol; L 2 =2-((3,4-dimethylisoxazol-5-ylimino)methyl)-5-methoxyphenol were synthesized and characterized by elemental analysis, 1 H NMR, 13 C NMR, FT-IR, ESI mass, UV-Visible, magnetic moment, ESR, SEM and powder XRD studies. Based on these results, a square planar geometry is assigned for all the metal complexes where the Schiff base acts as uninegatively charged bidentate chelating agent via the hydroxyl oxygen and azomethine nitrogen atoms. DNA binding studies of all the complexes with calf thymus DNA have been comprehensively investigated using electronic absorption spectroscopy, fluorescence quenching and viscosity studies. The oxidative and photo cleavage affinity of metal complexes towards supercoiled pBR322 DNA has been ascertained by agarose gel electrophoresis assay. From the results, it is observed that all the metal complexes bind effectively to CT-DNA via an intercalative mode of binding and also cleave pBR322 DNA in a promising manner. Further the Cu(II) complexes have shown better binding and cleavage properties towards DNA. The antimicrobial activities of the Schiff bases and their metal complexes were studied on bacterial and fungal strains and the results denoted that the complexes are more potent than their Schiff base ligands. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione

NASA Astrophysics Data System (ADS)

Singh, Ajay K.; Pandey, O. P.; Sengupta, S. K.

2013-09-01

Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L = monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2‧(OOCCH3)2(H2O)2](L‧ = neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, 1H NMR, and 13C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200 nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases.

Crystal structures of the F and pSLT plasmid TraJ N-terminal regions reveal similar homodimeric PAS folds with functional interchangeability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Jun; Wu, Ruiying; Adkins, Joshua N.

2014-09-16

In the F-family of conjugative plasmids, TraJ is an essential transcriptional activator of the tra operon that encodes most of the proteins required for conjugation. Here we report for the first time the X-ray crystal structures of the TraJ N-terminal regions from the prototypic F plasmid (TraJF11-130) and from the Salmonella virulence plasmid pSLT (TraJpSLT 1-128). Both proteins form similar homodimeric Per-ARNT-Sim (PAS) fold structures. Mutational analysis reveals that the observed dimeric interface is critical for TraJF transcriptional activation, indicating that dimerization of TraJ is required for its in vivo function. An artificial ligand (oxidized dithiothreitol) occupies a cavity inmore » the TraJF dimer interface, while a smaller cavity in corresponding region of the TraJpSLT structure lacks a ligand. Gas chromatography/mass spectrometry-electron ionization analysis of dithiothreitol-free TraJF suggests indole may be the natural TraJ ligand; however, disruption of the indole biosynthetic pathway does not affect TraJF function. Heterologous PAS domains from pSLT and R100 TraJ can functionally replace the TraJF PAS domain, suggesting that TraJ allelic specificity is mediated by the region C-terminal to the PAS domain.« less

SOD activity and DNA binding properties of a new symmetric porphyrin Schiff base ligand and its metal complexes.

PubMed

Çay, Sevim; Köse, Muhammet; Tümer, Ferhan; Gölcü, Ayşegül; Tümer, Mehmet

2015-12-05

4-Methoxy-2,6-bis(hydroxymethyl)phenol (1) was prepared from the reaction of 4-methoxyphenol and formaldehyde. The compound (1) was then oxidized to the 4-methoxy-2,6-diformylphenol (2) compound. Molecular structure of compound (2) was determined by X-ray diffraction method. A new symmetric porphyrin Schiff base ligand 4-methoxy-2,6-bis[5-(4-iminophenyl)-10,15,20-triphenylporphyrin]phenol (L) was prepared from the reaction of the 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (TTP-NH2) and the compound (2) in the toluene solution. The metal complexes (Cu(II), Fe(III), Mn(III), Pt(II) and Zn(II)) of the ligand (L) were synthesized and characterized by the spectroscopic and analytical methods. The DNA (fish sperm FSdsDNA) binding studies of the ligand and its complexes were performed using UV-vis spectroscopy. Additionally, superoxide dismutase activities of the porphyrin Schiff base metal complexes were investigated. Additionally, electrochemical, photoluminescence and thermal properties of the compounds were investigated. Copyright © 2015 Elsevier B.V. All rights reserved.

NPAS1-ARNT and NPAS3-ARNT crystal structures implicate the bHLH-PAS family as multi-ligand binding transcription factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Dalei; Su, Xiaoyu; Potluri, Nalini

Here, the neuronal PAS domain proteins NPAS1 and NPAS3 are members of the basic helix-loop-helix-PER-ARNT-SIM (bHLH-PAS) family, and their genetic deficiencies are linked to a variety of human psychiatric disorders including schizophrenia, autism spectrum disorders and bipolar disease. NPAS1 and NPAS3 must each heterodimerize with the aryl hydrocarbon receptor nuclear translocator (ARNT), to form functional transcription complexes capable of DNA binding and gene regulation. Here we examined the crystal structures of multi-domain NPAS1-ARNT and NPAS3-ARNT-DNA complexes, discovering each to contain four putative ligand-binding pockets. Through expanded architectural comparisons between these complexes and HIF-1α-ARNT, HIF-2α-ARNT and CLOCK-BMAL1, we show the widermore » mammalian bHLH-PAS family is capable of multi-ligand-binding and presents as an ideal class of transcription factors for direct targeting by small-molecule drugs.« less

NPAS1-ARNT and NPAS3-ARNT crystal structures implicate the bHLH-PAS family as multi-ligand binding transcription factors

DOE PAGES

Wu, Dalei; Su, Xiaoyu; Potluri, Nalini; ...

2016-10-26

Here, the neuronal PAS domain proteins NPAS1 and NPAS3 are members of the basic helix-loop-helix-PER-ARNT-SIM (bHLH-PAS) family, and their genetic deficiencies are linked to a variety of human psychiatric disorders including schizophrenia, autism spectrum disorders and bipolar disease. NPAS1 and NPAS3 must each heterodimerize with the aryl hydrocarbon receptor nuclear translocator (ARNT), to form functional transcription complexes capable of DNA binding and gene regulation. Here we examined the crystal structures of multi-domain NPAS1-ARNT and NPAS3-ARNT-DNA complexes, discovering each to contain four putative ligand-binding pockets. Through expanded architectural comparisons between these complexes and HIF-1α-ARNT, HIF-2α-ARNT and CLOCK-BMAL1, we show the widermore » mammalian bHLH-PAS family is capable of multi-ligand-binding and presents as an ideal class of transcription factors for direct targeting by small-molecule drugs.« less

Synthesis, characterization of 1,2,4-triazole Schiff base derived 3d-metal complexes: Induces cytotoxicity in HepG2, MCF-7 cell line, BSA binding fluorescence and DFT study

NASA Astrophysics Data System (ADS)

Tyagi, Prateek; Tyagi, Monika; Agrawal, Swati; Chandra, Sulekh; Ojha, Himanshu; Pathak, Mallika

2017-01-01

Two novel Schiff base ligands H2L1 and H2L2 have been synthesized by condensation reaction of amine derivative of 1,2,4-triazole moiety with 2-hydroxy-4-methoxybenzaldehyde. Co(II), Ni(II), Cu(II) and Zn(II) of the synthesized Schiff bases were prepared by using a molar ratio of ligand:metal as 1:1. The structure of the Schiff bases and synthesized metal complexes were established by 1H NMR, UV-Vis, IR, Mass spectrometry and molar conductivity. The thermal stability of the complexes was study by TGA. Fluorescence quenching mechanism of metal complexes 1-4 show that Zn(II) and Cu(II) complex binds more strongly to BSA. In DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31 + g(d,p) basis set. The spectral data shows that the ligands behaves as binegative tridentate. On the basis of the spectral studies, TGA and DFT data an octahedral geometry has been assigned for Co(II), Ni(II), square planar for Cu(II) and tetrahedral for Zn(II) complexes. The anticancer activity were screened against human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (Hep-G2). Result indicates that metal complexes shows increase cytotoxicity in proliferation to cell lines as compared to free ligand.

Improvement in Titanium Complexes Bearing Schiff Base Ligands in the Ring-Opening Polymerization of L-Lactide: A Dinuclear System with Hydrazine-Bridging Schiff Base Ligands.

PubMed

Tseng, Hsi-Ching; Chen, Hsing-Yin; Huang, Yen-Tzu; Lu, Wei-Yi; Chang, Yu-Lun; Chiang, Michael Y; Lai, Yi-Chun; Chen, Hsuan-Ying

2016-02-15

A series of titanium (Ti) complexes bearing hydrazine-bridging Schiff base ligands were synthesized and investigated as catalysts for the ring-opening polymerization (ROP) of L-lactide (LA). Complexes with electron withdrawing or steric bulky groups reduced the catalytic activity. In addition, the steric bulky substituent on the imine groups reduced the space around the Ti atom and then reduced LA coordination with Ti atom, thereby reducing catalytic activity. All the dinuclear Ti complexes exhibited higher catalytic activity (approximately 10-60-fold) than mononuclear L(Cl-H)-TiOPr2 did. The strategy of bridging dinuclear Ti complexes with isopropoxide groups in the ROP of LA was successful, and adjusting the crowded heptacoordinated transition state by the bridging isopropoxide groups may be the key to our successful strategy.

Origin of SMM behaviour in an asymmetric Er(III) Schiff base complex: a combined experimental and theoretical study.

PubMed

Das, Chinmoy; Upadhyay, Apoorva; Vaidya, Shefali; Singh, Saurabh Kumar; Rajaraman, Gopalan; Shanmugam, Maheswaran

2015-04-11

An asymmetric erbium(III) Schiff base complex [Er(HL)2(NO3)3] was synthesized which shows SMM behaviour with an Ueff of 5.2 K. Dipolar interaction in 1 significantly reduced upon dilution which increases the barrier height to 51.5 K. Ab initio calculations were performed to shed light on the mechanism of magnetization relaxation.

Inhibition of copper-mediated aggregation of human γD-crystallin by Schiff bases.

PubMed

Chauhan, Priyanka; Muralidharan, Sai Brinda; Velappan, Anand Babu; Datta, Dhrubajyoti; Pratihar, Sanjay; Debnath, Joy; Ghosh, Kalyan Sundar

2017-06-01

Protein aggregation, due to the imbalance in the concentration of Cu 2+ and Zn 2+ ions is found to be allied with various physiological disorders. Copper is known to promote the oxidative damage of β/γ-crystallins in aged eye lens and causes their aggregation leading to cataract. Therefore, synthesis of a small-molecule 'chelator' for Cu 2+ with complementary antioxidant effect will find potential applications against aggregation of β/γ-crystallins. In this paper, we have reported the synthesis of different Schiff bases and studied their Cu 2+ complexation ability (using UV-Vis, FT-IR and ESI-MS) and antioxidant activity. Further based on their copper complexation efficiency, Schiff bases were used to inhibit Cu 2+ -mediated aggregation of recombinant human γD-crystallin (HGD) and β/γ-crystallins (isolated from cataractous human eye lens). Among these synthesized molecules, compound 8 at a concentration of 100 μM had shown ~95% inhibition of copper (100 μM)-induced aggregation. Compound 8 also showed a positive cooperative effect at a concentration of 5-15 μM on the inhibitory activity of human αA-crystallin (HAA) during Cu 2+ -induced aggregation of HGD. It eventually inhibited the aggregation process by additional ~20%. However, ~50% inhibition of copper-mediated aggregation of β/γ-crystallins (isolated from cataractous human eye lens) was recorded by compound 8 (100 μM). Although the reductive aminated products of the imines showed better antioxidant activity due to their lower copper complexing ability, they were found to be non-effective against Cu 2+ -mediated aggregation of HGD.

1,2,4-triazole derivative with Schiff base; thiol-thione tautomerism, DFT study and antileishmanial activity

NASA Astrophysics Data System (ADS)

Süleymanoğlu, Nevin; Ustabaş, Reşat; Direkel, Şahin; Alpaslan, Yelda Bingöl; Ünver, Yasemin

2017-12-01

Thiol-thione tautomerism of 1,2,4-triazole derivative with Schiff base was investigated by spectroscopic methods and quantum mechanical calculations. Theoretical study of thiol-thione tautomeric forms of 1,2,4-triazole derivative with Schiff base; 1,2,4-triazole-thiol form, 1-((5-mercapto-4-(thiophene-2-ylmethyleneamino)-4H-1,2,4-triazole-3-yl)methyl)-3-(thiophene-2-ylmethyl)-4-(thiophene-2-ylmethyleneamino)-1H-1,2,4-triazole-5(4H)-one (I) and 1,2,4-triazole-thione form, 3-(thiophene-2-ylmethyl)-4-(thiophene-2-ylmethyleneamino)-1-((4-(thiophene-2-ylmethyleneamino)-5-thioxo-4,5-dihydro-1H-1,2,4-triazole-3-yl)methyl)-1H-1,2,4-triazole-5(4H)-one (II) was performed by the density functional theory (DFT) method with 6-311++G(d,p) basis set. Structural parameters were obtained and spectral parameters of NMR, FTIR and UV-vis were compared with experimental ones to determine structural details. In vitro antileishmanial activity was studied against Leishmania infantum promastigots by microdilution broth assay with Alamar Blue Dye. The results indicate that 1,2,4-triazole derivative exists in both thiol and thione form and, can be evaluated as antiparasitic in term of antileishmanial activity.

Synthesis, structure, DNA/BSA binding and antibacterial studies of NNO tridentate Schiff base metal complexes

NASA Astrophysics Data System (ADS)

Sakthi, Marimuthu; Ramu, Andy

2017-12-01

A new salicylaldehyde derived 2,4-diiodo-6-((2-phenylaminoethylimino)methyl)phenol Schiff base(L) and its transition metal complexes of the type MLCl where, M = Cu(II), Ni(II), Co(II), Mn(II) and Zn(II) have been synthesized. The coordination mode of Schiff base holding NNO donor atoms with metal ions was well investigated by elemental analysis, ESI-mass as well as IR, UV-vis, CV and NMR spectral studies. The binding efficiency and mode of these complexes with biological macromolecules viz., herring sperm DNA (HS- DNA) and bovine serum albumin (BSA) have been explored through various spectroscopic techniques. The characteristic changes in absorption, emission and, circular dichroism spectra of the complexes with DNA indicate the noticeable interaction between them. From the all spectral information complexes could interact with DNA via non-intercalation mode of binding. The hyperchromisim in absorption band and hypochromisim in emission intensity of BSA with different complex concentrations shown significant information, and the binding affinity value has been predicted from Stern-Volmer plots. Further, all the complexes could cleave the circular plasmid pUC19 DNA efficiently by using an activator H2O2. The ligand and all metal(II) complexes showed good antibacterial activities. The molecular docking studies of the complexes with DNA were performed in order to make a comparison and conclusion with spectral technic results.

Structure and Activity Changes of Phytohemagglutinin from Red Kidney Bean (Phaseolus vulgaris) Affected by Ultrahigh-Pressure Treatments.

PubMed

Lu, Yunjun; Liu, Cencen; Zhao, Mouming; Cui, Chun; Ren, Jiaoyan

2015-11-04

Phytohemagglutin (PHA), purified from red kidney beans (Phaseolus vulgaris) by Affi-Gel blue affinity chromatography, was subjected to ultrahigh-pressure (UHP) treatment (150, 250, 350, and 450 MPa). The purified PHA lost its hemagglutination activity after 450 MPa treatment and showed less pressure tolerance than crude PHA. However, the saccharide specificity and α-glucosidase inhibition activity of the purified PHA did not change much after UHP treatment. Electrophoresis staining by periodic acid-Schiff (PAS) manifested that the glycone structure of purified PHA remained stable even after 450 MPa pressure treatment. However, electrophoresis staining by Coomassie Blue as well as circular dichroism (CD) and differential scanning calorimetry (DSC) assay proved that the protein unit structure of purified PHA unfolded when treated at 0-250 MPa but reaggregates at 250-450 MPa. Therefore, the hemagglutination activity tends to be affected by the protein unit structure, while the stability of the glycone structure contributed to the remaining α-glucosidase inhibition activity.

Deprotonation of hydrogen bonded Schiff bases by three strong nitrogen bases

NASA Astrophysics Data System (ADS)

Schilf, Wojciech; Cmoch, Piotr; Szady-Chełmieniecka, Anna; Grech, Eugeniusz

2009-03-01

Three Schiff bases obtained from substituted salicylaldehydes and 2-hydroxy-1-naphthaldehyde and aliphatic amines were investigated in terms of possible withdrawal of tautomeric proton from intramolecular hydrogen bridge. Three strong nitrogen bases: 1,8-bis(dimethylamino)naphtalene (DMAN), 1,1,3,3-tetramethylguanidine (TMG) and 1,8-bis(tetramethylguanidino)naphthalene (TMGN) were used as deprotonating agents in acetonitrile solution at room temperature. In the specified conditions it was found that only in the case of 5-nitrosalicylaldehyde and isopropyl amine derivative this process could be performed using TMG and TMGN as a base. The other derivatives, where bridged proton is shifted to oxygen or nitrogen atom, do not undergo such reaction. The deprotonation process was monitored by nitrogen and proton NMR measurements.

Development of Physics Attitude Scale (PAS): An Instrument to Measure Students' Attitudes toward Physics

ERIC Educational Resources Information Center

Kaur, Daisy; Zhao, Yi

2017-01-01

The present study is focused on the detailed description of Physics Attitude Scale (PAS) to measure students' attitudes toward physics. The development of this new instrument involved extensive interviews with both the experts as well as the students. This was followed by expert reviews and pilot testing of the instrument. The duly revised draft…

A Schiff-based colorimetric fluorescent sensor with the potential for detection of fluoride ions.

PubMed

Huang, Cheng-Yin; Wan, Chin-Feng; Chir, Jiun-Ly; Wu, An-Tai

2013-11-01

A simple Schiff-based colorimetric fluorescent receptor 1 was prepared. It exhibits a "turn-on-type" mode with high sensitivity in the presence of F(-). The change in color is very easily observed by the naked eye in the presence of F(-), whereas other anions do not induce such a change. Job plot indicated a 1:2 complexation stoichiometry between receptor 1 and F(-). The association constant for 1-F(-) in CH3CN was determined as 1.32*10(5) M(-2) by a Hill plot.

[Significance of MUC5B antibody in differential diagnosis between Aspergillus species and Mucorales of fungal sinusitis].

PubMed

Piao, Ying-shi; Liu, Hong-gang; Liu, Xian-jun

2008-04-01

To differentiate between Aspergillus species and Mucorales of fungal sinusitis by immunohistochemistry. Formalin-fixed paraffin-embedded tissue blocks of 66 cases of fungal sinusitis were retrieved from the archival files of Department of Pathology of Beijing Tongren Hospital during the period from 2001 to 2006. The samples included 29 cases of fungal balls, 12 cases of allergic fungal sinusitis, 24 cases of chronic invasive fungal sinusitis and 1 case of acute invasive fungal sinusitis. The types of fungi were 44 Aspergillus species (31 cases of A. fumigatus, 7 cases of A. flavus and 6 cases of A. terreus) and 22 Mucorales (14 cases of Mucor species and 8 cases of Rhizopus species). Immunohistochemistry was performed with MUC2, MUC5AC and MUC5B antibodies. The results were compared with histochemical study for periodic acid-Schiff (PAS) and Grocott methenamine silver (GMS) stains. Immunohistochemical study for MUC5B showed that the positive rate of Aspergillus species was 90.9%, in contrast to 4.5% in Mucorales (P < 0.001). The expression of MUC2 and MUC5AC was completely negative, whereas PAS and GMS stains were positive in all cases. MUC5B antibody appears to be a useful immunohistochemical marker for identifying fungal types in tissue sections, especially in distinguishing between Aspergillus species and Mucorales in fungal sinusitis.

Synthesis, spectral characterization, structural investigation and antimicrobial studies of mononuclear Cu(II), Ni(II), Co(II), Zn(II) and Cd(II) complexes of a new potentially hexadentate N2O4 Schiff base ligand derived from salicylaldehyde

NASA Astrophysics Data System (ADS)

Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Chalabian, Firoozeh; Elerman, Yalcin; Buyukgungor, Orhan

2013-01-01

A new potentially hexadentate N2O4 Schiff base ligand, H2L derived from condensation reaction of an aromatic diamine and salicylaldehyde, and its metal complexes were characterized by elemental analyses, IR, UV-Vis, EI-MS, 1H and 13C NMR spectra, as well as conductance measurements. It has been originated that the Schiff base ligand with Cu(II), Ni(II), Co(II), Cd(II) and Zn(II) ions form mononuclear complexes on 1:1 (metal:ligand) stoichiometry. The conductivity data confirm the non-electrolytic nature of the complexes. Also the crystal structures of the complexes [ZnL] and [CoL] have also been determined by using X-ray crystallographic technique. The Zn(II) and Co(II) complexes show a tetrahedral configuration. Electronic absorption spectra of the Cu(II) and Ni(II) complexes suggest a square-planar geometry around the central metal ion. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Bacillus cereus, Enterococcus faecalis and Listeria monocytogenes and also against the three Gram-negative bacteria: Salmonella paraB, Citrobacter freundii and Enterobacter aerogenes. The results showed that in some cases the antibacterial activity of complexes were more than nalidixic acid and amoxicillin as standards.

Extinction, seeing and sky transparency monitoring at the Observatorio Astrofísico de Javalambre for J-PAS and J-PLUS calibration and scheduling

NASA Astrophysics Data System (ADS)

Vázquez Ramió, H.; Díaz-Martín, M. C.; Varela, J.; Ederoclite, A.; Maícas, N. Lamadrid, J. L.; Abril, J.; Iglesias-Marzoa, R.; Rodríguez, S.; Tilve, V.; Cenarro, A. J.; Antón Bravo, J. L.; Bello Ferrer, R.; Cristóbal-Hornillos, D.; Guillén Civera, L.; Hernández-Fuertes, J.; Jiménez Mejías, D.; Lasso-Cabrera, N. M.; López Alegre, G.; López Sainz, A.; Luis-Simoes, R. M.; Marín-Franch, A.; Moles, M.; Rueda-Teruel, F.; Rueda-Teruel, S.; Suárez López, O.; Yanes-Díaz, A.

2015-05-01

The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS; see Benítez et al. 2014) and the Javalambre-Photometric Local Universe Survey (J-PLUS) will be conducted at the brand-new Observatorio Astrofísico de Javalambre (OAJ) in Teruel, Spain. J-PLUS is planned to start by the first half of 2015 while J-PAS first light is expected to happen along 2015. Besides the two main telescopes (with 2.5 m and 80 cm apertures), several smaller-sized facilities are present at the OAJ devoted to site characterization and supporting measurements to be used to calibrate the J-PAS and J-PLUS photometry and to feed up the OAJ's Sequencer with the integrated seeing and the sky transparency. These instruments are: i) an extinction monitor, an 11 " telescope estimating the atmospheric extinction to finally obtain the OAJ extinction curve, which is the initial step to J-PAS overall photometric calibration procedure; ii) an 8 " telescope implementing the Differential Image Motion Monitor (DIMM) technique to obtain the integrated seeing; and iii) an All-Sky Transmission MONitor (ASTMON), a roughly all-sky instrument providing the sky transparency as well as sky brightness and the atmospheric extinction too.

Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione.

PubMed

Singh, Ajay K; Pandey, O P; Sengupta, S K

2013-09-01

Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L=monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2(')(OOCCH3)2(H2O)2](L'=neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, (1)H NMR, and (13)C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases. Copyright © 2013 Elsevier B.V. All rights reserved.

Hydrothermally tailor-made chitosan fiber for micro-solid phase extraction of petroleum acids in crude oils.

PubMed

Zhu, Gang-Tian; Hu, Xiao-Li; He, Sheng; He, Xiao-Mei; Zhu, Shu-Kui; Feng, Yu-Qi

2018-06-05

Tailor-made chitosan fiber was prepared via hydrothermal treatment to serve as a micro-solid phase extraction (micro-SPE) sorbent for the analysis of petroleum acids (PAs) in crude oils. Chitosan fiber, which is commercial and cheap, has a diameter of about 10 μm and a length of a few centimeters. The fibrous property of the sorbent enables the micro-SPE to deal with viscous crude oil samples because of the low back-pressure during extraction, while the abundant hydroxyl groups and amino groups on the surface of chitosan fiber can provide high density of specific sites for adsorption of PAs. Moreover, it was found that hydrothermal treatment at certain conditions could tune the surface properties of chitosan fiber, leading to significant improvement of the capacity of the fiber in adsorption of PAs. Using hydrothermally treated chitosan fiber as sorbent, the micro-SPE was applied to the determination of PAs in crude oils, with the advantages of easy-operation, rapidness and high sensitivity (the limits of detection range from 0.7 ng/g to 5.4 ng/g). Furthermore, coupled with comprehensive two dimensional gas chromatography-mass spectrometry (GC × GCMS), the treated chitosan fiber packed micro-SPE method showed a great potential for comprehensive profiling of PAs in crude oils. Copyright © 2018 Elsevier B.V. All rights reserved.

Synthesis, solvatochromaticity and bioactivities of some transition metal complexes with 2-(R-benzylideneamino)-pyridin-3-ol Schiff base derivatives

NASA Astrophysics Data System (ADS)

Ahmed, I. S.; Kassem, M. A.

2010-10-01

New four Schiff bases are prepared by condensation of 2-amino-pyridin-3-ol with 3, 4-dihydroxy-benzaldehyde (I), 2-hydroxybenzaldehyde (II), 5-bromo-2-hydroxybenzaldehyde (III), and 4-dimethylaminobenzaldehyde (IV). The structures of these compounds are characterized based on elemental analyses (C. H. N), IR and 1H NMR. Also, the electronic absorption spectra are recorded in organic solvents of different polarity. The solvents are selected to be covered a wide range of parameters (refractive index, dielectric constant and hydrogen bonding capacity). The UV-vis absorption spectra of Schiff base compounds are investigated in aqueous buffer solutions of varying pH and utilized for the determination of ionization constant, p Ka and activation free energy, Δ G* of the ionization process. The biological activity against bacterial species and fungi as microorganisms representing different microbial categories such as (two Gram-negative bacteria, Eschericha coli and Agrobacterium sp.),three Gram-positive bacteria ( Staphylococcus aureus, Bacillus subtlus and Bacillus megatherium), yeast ( Candida albicans), and fungi ( Aspergillus niger) were studied.

TDDFT calculations and photoacoustic spectroscopy experiments used to identify phenolic acid functional biomolecules in Brazilian tropical fruits in natura

NASA Astrophysics Data System (ADS)

Lourenço Neto, M.; Agra, K. L.; Suassuna Filho, J.; Jorge, F. E.

2018-03-01

Time-dependent density functional theory (TDDFT) calculations of electronic transitions have been widely used to determine molecular structures. The excitation wavelengths and oscillator strengths obtained with the hybrid exchange-correlation functional B3LYP in conjunction with the ADZP basis set are employed to simulate the UV-Vis spectra of eight phenolic acids. Experimental and theoretical UV-Vis spectra reported previously in the literature are compared with our results. The fast, sensitive and non-destructive technique of photoacoustic spectroscopy (PAS) is used to determine the UV-Vis spectra of four Brazilian tropical fresh fruits in natura. Then, the PAS along with the TDDFT results are for the first time used to investigate and identify the presence of phenolic acids in the fruits studied in this work. This theoretical method with this experimental technique show to be a powerful and cheap tool to detect the existence of phenolic acids in fruits, vegetables, cereals, and grains. Comparison with high performance liquid chromatography results, when available, is also carried out.

Newer mixed ligand Schiff base complexes from aquo-N-(2‧-hydroxy acetophenone) glycinatocopper(II) as synthon: DFT, antimicrobial activity and molecular docking study

NASA Astrophysics Data System (ADS)

Pramanik, Harun A. R.; Das, Dharitri; Paul, Pradip C.; Mondal, Paritosh; Bhattacharjee, Chira R.

2014-02-01

Synthesis of a series of newer mixed ligand copper(II) complexes of aminoacid Schiff base of the type [CuL(X)] (L = N-(2‧-hydroxy acetophenone) glycinate, X = imidazole (im) 2, benzimidazole (benz) 3, pyridine (py) 4, hydrazine (hz) 5,8-hydroxyquinoline (8-hq) 6, pyrrolidine (pyrr) 7, piperidine (pip) 8, and nicotinamide (nic) 9) have been accomplished from the interaction of an aquated Schiff base complex, [CuL(H2O)]·H2O, 1 with some selected neutral nitrogen-donor ligands. The copper(II) Schiff base complex, [CuL(H2O)]·H2O, L = N-(2‧-hydroxy acetophenone) glycinate was synthesized from the reaction of glycine and 2‧ hydroxy acetophenone and copper(II) acetate. The compounds were characterised by elemental analysis, spectral, magnetic and thermal studies. The density functional theory calculations were performed using LANL2DZ and 6-311 G(d, p) basis sets with B3LYP correlation functional to ascertain the stable electronic structure, HOMO-LUMO energy gap, chemical hardness and dipole moment of the mixed ligand complexes. A distorted square planar geometry has been conjectured for the complexes. Antibacterial activities of the ligand and its metal complexes have been tested against selected gram-positive and gram-negative strains and correlated with computational docking scores.

Synthesis, characterisation and DFT studies of three Schiff bases derived from histamine

NASA Astrophysics Data System (ADS)

Touafri, Lasnouni; Hellal, Abdelkader; Chafaa, Salah; Khelifa, Abdellah; Kadri, Abdelaziz.

2017-12-01

In this paper, we report first, the synthesis and characterisation of three Schiff bases derived from histamine by condensation of histamine with various aldehydes. Then, we present a detailed DFT study based on B3LYP/6-31G(d,p) of geometrical structures and electronic properties of these compounds. The study was extended to the HOMO-LUMO analysis to calculate the energy gap (Δ), Ionisation potential (I), Electron Affinity (A), Global Hardness (η), Chemical Potential (μ), Electrophilicity (ω), Electronegativity (χ) and Polarisability (α). The calculated HOMO and LUMO energy reveals that the charge transfers occurring within the molecule. On the basis of vibration analyses, the thermodynamic properties of the titles compound were also calculated.

Solute-solvent interactions in chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane at 308.15 K according to ultrasonic and viscosity data

NASA Astrophysics Data System (ADS)

Gangani, B. J.; Patel, J. P.; Parsania, P. H.

2015-12-01

The density, viscosity and ultrasonic speed (2 MHz) of chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane were investigated at 308.15 K. Various acoustical parameters such as specific acoustical impedance ( Z), adiabatic compressibility ( Ka), Rao's molar sound function ( R m), van der Waals constant ( b), internal pressure (π), free volume ( V f), intermolecular free path length ( L f), classical absorption coefficient (α/ f 2)Cl) and viscous relaxation time (τ) were determine using ultrasonic speed ( U), viscosity (η) and density (ρ) data of Schiff bases solutions and correlated with concentration. Linear increase of Z, b, R, τ, and (α/ f 2)Cl except π (nonlinear) and linear decrease of Ka and L f except V f (nonlinear) with increasing concentration of Schiff bases suggested presence of strong molecular interactions in the solutions. The positive values of solvation number further supported strong molecular interactions in the solutions. The nature and position of halogen substituent also affected the strength of molecular interactions.

Toxic pyrrolizidinalkaloids as undesired contaminants in food and feed: degradation of the PAs from Senecio jacobaea in silage.

PubMed

Becerra-Jiminez, J; Kuschak, M; Roeder, E; Wiedenfeld, H

2013-07-01

Pyrrolizidine alkaloids (PAs) can show a hazardous potential for men and animals. They can act as cancerogenic, mutagenic, teratogenic and fetotoxic agents. One pathway of a human intoxication is its occurence as contaminants in food and feed. Here, the contamination of cereals already led to severe and fatal intoxication episodes. Besides this, milk is of special concern as it is the main food for children which show a very high susceptibility for a PA intoxication. Milk can contain PAs in case the milk producing animals have access to contaminated feed. In this context it is of special interest whether the PA content of contaminated silage remains stable during the ensiling procedure or show a more or less high level of decomposition. We could show that ensiling will not lead to PA-free silage.

Psychometric properties and norms of the German ABC-Community and PAS-ADD Checklist.

PubMed

Zeilinger, Elisabeth L; Weber, Germain; Haveman, Meindert J

2011-01-01

The aim of the present study was to standardize and generate psychometric evidence of the German language versions of two well-established English language mental health instruments: the Aberrant Behavior Checklist-Community (ABC-C) and the Psychiatric Assessment Schedule for Adults with Developmental Disabilities (PAS-ADD) Checklist. New methods in this field were introduced: a simulation method for testing the factor structure and an exploration of long-term stability over two years. The checklists were both administered to a representative sample of 270 individuals with intellectual disability (ID) and, two years later in a second data collection, to 128 participants of the original sample. Principal component analysis and parallel analysis were performed. Reliability measures, long-term stability, subscale intercorrelations, as well as standardized norms were generated. Prevalence of mental health problems was examined. Psychometric properties were mostly excellent, with long-term stability showing moderate to strong effects. The original factor structure of the ABC-C was replicated. PAS-ADD Checklist produced a similar, but still different structure compared with findings from the English language area. The overall prevalence rate of mental health problems in the sample was about 20%. Considering the good results on the measured psychometric properties, the two checklists are recommended for the early detection of mental health problems in persons with ID. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ovarian structure and hormonal status of the UChA and UChB adult rats in response to ethanol.

PubMed

Chuffa, Luiz Gustavo A; Padovani, Carlos R; Martinez, Francisco E

2009-01-20

In females, chronic alcoholism has a current and dangerous incidence to fertility. This work had the goal of elucidating the alterations on the ovary of UChA and UChB adult rats (ethanol 10% (v/v) voluntary drinkers). After the treatment period, 42 female rats divided into three experimental groups (UChA, UChB and Wistar) suffered decapitation and their ovaries were removed and processed to further analysis on light and electron microscopy. The ovary was entirely sliced and stained by hematoxylin-eosin, toluidine blue, periodic acid Schiff (PAS) and Masson's tricromic. Thereby, the enzymatic reaction to acid and alkaline phosphatase, estral cyclicity, reproductive hormonal status and frequency in oestrous-related ovarian structures were assigned. The UChB rats showed an increase in body mass gain index and the ovaries relative weight was significantly lower comparing to the other groups. UCh rats presented the longest estral cycle durations and also persistent oestrous phasis, with uninterrupted cycles. Advanced follicular atresia was common in UCh animals, and degenerating intracellular fragments could be observed through acid phosphatase and electron microscopy techniques. There were some estral cyclicity irregularities caused by chronic ethanol intake in the UCh groups which were consequently reflected as morphologic injury in the ovary structure.

N-acetyltransferase genotypes and the pharmacokinetics and tolerability of para-aminosalicylic acid in patients with drug-resistant pulmonary tuberculosis.

PubMed

Sy, Sherwin K B; de Kock, Lizanne; Diacon, Andreas H; Werely, Cedric J; Xia, Huiming; Rosenkranz, Bernd; van der Merwe, Lize; Donald, Peter R

2015-07-01

The aim of this study was to examine the relationships between N-acetyltransferase genotypes, pharmacokinetics, and tolerability of granular slow-release para-aminosalicylic acid (GSR-PAS) in tuberculosis patients. The study was a randomized, two-period, open-label, crossover design wherein each patient received 4 g GSR-PAS twice daily or 8 g once daily alternately. The PAS concentration-time profiles were modeled by a one-compartment disposition model with three transit compartments in series to describe its absorption. Patients' NAT1 and NAT2 genotypes were determined by sequencing and restriction enzyme analysis, respectively. The number of daily vomits was modeled by a Poisson probability mass function. Comparisons of other tolerability measures by regimens, gender, and genotypes were evaluated by a linear mixed-effects model. The covariate effects associated with efavirenz, gender, and NAT1*3, NAT1*14, and NAT2*5 alleles corresponded to 25, 37, -17, -48, and -27% changes, respectively, in oral clearance of PAS. The NAT1*10 allele did not influence drug clearance. The time above the MIC of 1 mg/liter was significantly different between the two regimens but not influenced by the NAT1 or NAT2 genotypes. The occurrence and intensity of intolerance differed little between regimens. Four grams of GSR-PAS twice daily but not 8 g once daily ensured concentrations exceeding the MIC (1 mg/liter) throughout the dosing interval; PAS intolerance was not related to maximum PAS concentrations over the doses studied and was not more frequent after once-daily dosing. We confirm that the slow phenotype conferred by the NAT1*14 and NAT1*3 alleles resulted in higher PAS exposure but found no evidence of increased activity of the NAT1*10 allele. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

A soft tissue adhesive based on aldehyde-sodium alginate and amino-carboxymethyl chitosan preparation through the Schiff reaction

NASA Astrophysics Data System (ADS)

Wu, Yu; Yuan, Liu; Sheng, Nai-an; Gu, Zi-qi; Feng, Wen-hao; Yin, Hai-yue; Morsi, Yosry; Mo, Xiu-mei

2017-09-01

Sodium alginate and carboxymethyl chitosan have been extensively applied in tissue engineering and other relative fields due to their low price and excellent biocompatibility. In this paper, we oxidized sodium alginate with sodium periodate to convert 1,2-hydroxyl groups into aldehyde groups to get aldehyde-sodium alginate (ASA). Carboxymethyl chitosan was modified with ethylenediamine (ED) in the presence of water-soluble N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) to introduce additional amino groups to get amino-carboxymethyl chitosan (A-CS). Upon mixing the A-SA and A-CS aqueous solutions together, a gel rapidly formed based on the Schiff's base reaction between aldehyde groups in A-SA and amino groups in A-CS. FTIR analysis confirmed the characteristic peak of Schiff's base group in the hydrogel. It was confirmed that the gelation time be dependent on the aldehyde group content in A-SA and amino group content in A-CS. The fasted hydrogel formation takes place within 10 min. The data of bonding strength and cytotoxicity measurement also showed that the hydrogel had good adhesion and biocompatibility. All these results support that this gel has the potential as soft tissue adhesive.

Simultaneous determination of isoniazid and p-aminosalicylic acid by capillary electrophoresis using chemiluminescence detection.

PubMed

Zhang, Xinfeng; Xuan, Yuelan; Sun, Aimin; Lv, Yi; Hou, Xiandeng

2009-01-01

It was found that isoniazid (ISO) or p-aminosalicylic acid (PAS) could enhance the chemiluminescence (CL) emission from Cu (II)-luminol-hydrogen peroxide system, and the increased chemiluminescence signals were proportional to their concentrations, respectively. Based on this phenomenon, a chemiluminescence method coupled to capillary electrophoresis (CE) was established for simultaneous determination of ISO and PAS. The CE conditions including running buffer and running voltage were investigated in detail. The effects of the pH of H(2)O(2) solution and the concentrations of luminol, H(2)O(2) and Cu (II) on the CL signal were also investigated carefully. Under the optimized conditions, the analysis could be accomplished within 10 min, with the limits of detection of 0.3 microg mL(-1) for ISO and 1.1 microg mL(-1) for PAS, corresponding to 7.2 and 26.4 pg per injection (24 nL), respectively. Finally, the method was validated by determining the two analytes in pharmaceutical preparation and spiked human serum samples. The results of pharmaceutical tablet analysis were in good agreement with the labeled amounts. The recoveries for ISO and PAS in human serum were in the range of 92-104% and 90-113%, respectively. Copyright 2008 John Wiley & Sons, Ltd.

The chemical mechanism of sheep liver 6-phosphogluconate dehydrogenase. A Schiff-base intermediate is not involved.

PubMed Central

Topham, C M; Dalziel, K

1986-01-01

[2-18O]Ribulose 5-phosphate was prepared and shown to be converted enzymically by 6-phosphogluconate dehydrogenase from sheep liver into 6-phosphogluconate with complete retention of the heavy isotope. This finding unequivocally excludes the possibility of a Schiff-base mechanism for the enzyme. The involvement of metal ions has already been excluded, and other possible mechanisms are discussed. The enzyme was purified by an improved large-scale procedure, which is briefly described. PMID:3718491

Synthesis and characterization of a novel schiff base of 1,2-diaminopropane with substituted salicyaldehyde and its transition metal complexes: Single crystal structures and biological activities

NASA Astrophysics Data System (ADS)

Tadavi, Samina K.; Yadav, Abhijit A.; Bendre, Ratnamala S.

2018-01-01

A novel schiff base H2L derived from simple condensation of 2-hydroxy-6-isopropyl-3-methyl benzaldehyde and 1,2-diaminopropane in 2:1 M ratio and its [MnL], [CoL] and [NiL]2 complexes have been prepared and characterized by spectroscopic technique, elemental analysis, SEM-EDX analysis, and cyclic voltammetry. Additionally, single crystal X-ray diffraction technique has been applied to the schiff base ligand H2L and its nickel complex. The structure of nickel complex exhibited dimeric form with formula [NiL]2 with distorted square planar geometry around each nickel center. Furthermore, all the synthesized compounds were screened for their antimicrobial and antioxidant and DNA cleavage activities.

Novel homologous lactate transporter improves L-lactic acid production from glycerol in recombinant strains of Pichia pastoris.

PubMed

de Lima, Pollyne Borborema Almeida; Mulder, Kelly Cristina Leite; Melo, Nadiele Tamires Moreira; Carvalho, Lucas Silva; Menino, Gisele Soares; Mulinari, Eduardo; de Castro, Virgilio H; Dos Reis, Thaila F; Goldman, Gustavo Henrique; Magalhães, Beatriz Simas; Parachin, Nádia Skorupa

2016-09-15

Crude glycerol is the main byproduct of the biodiesel industry. Although it can have different applications, its purification is costly. Therefore, in this study a biotechnological route has been proposed for further utilization of crude glycerol in the fermentative production of lactic acid. This acid is largely utilized in food, pharmaceutical, textile, and chemical industries, making it the hydroxycarboxylic acid with the highest market potential worldwide. Currently, industrial production of lactic acid is done mainly using sugar as the substrate. Thus here, for the first time, Pichia pastoris has been engineered for heterologous L-lactic acid production using glycerol as a single carbon source. For that, the Bos taurus lactate dehydrogenase gene was introduced into P. pastoris. Moreover, a heterologous and a novel homologous lactate transporter have been evaluated for L-lactic acid production. Batch fermentation of the P. pastoris X-33 strain producing LDHb allowed for lactic acid production in this yeast. Although P. pastoris is known for its respiratory metabolism, batch fermentations were performed with different oxygenation levels, indicating that lower oxygen availability increased lactic acid production by 20 %, pushing the yeast towards a fermentative metabolism. Furthermore, a newly putative lactate transporter from P. pastoris named PAS has been identified by search similarity with the lactate transporter from Saccharomyces cerevisiae Jen1p. Both heterologous and homologous transporters, Jen1p and PAS, were evaluated in one strain already containing LDH activity. Fed-batch experiments of P. pastoris strains carrying the lactate transporter were performed with the batch phase at aerobic conditions followed by an aerobic oxygen-limited phase where production of lactic acid was favored. The results showed that the strain containing PAS presented the highest lactic acid titer, reaching a yield of approximately 0.7 g/g. We showed that P. pastoris has a

In vitro anti-glycation and anti-oxidant properties of synthesized Schiff bases.

PubMed

Jhaumeer-Laulloo, Sabina; Bhowon, Minu Gupta; Mungur, Shabneez; Mahomoodally, Mohamad Fawzi; Subratty, Anwar Hussein

2012-05-01

A series of mono, bis and mixed Schiff bases (1-7) were synthesised and evaluated for potential anti-glycation and anti-oxidant activities using the bovine serum albumin-glucose assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay respectively. All compounds showed significant (p<0.05) antiglycating activities with IC50 values (4.02x10(-24)±0.1-2.88x10(-1)±1.35 mM) which were lower than the standard positive control aminoguanidine (IC50: 1.51x10(-3)±2.11 mM). Moreover, compounds 1-7 were found to possess significant (p<0.05) DPPH radical scavenging properties with SC50 values (1.31x10(-19)±0.05 to 2.25x10(-1)±1.24 mM) lower than the standard ascorbic acid (SC50: 5.50x10(-3)±2.11 mM). Compound 6 was found to be the most potent anti-glycating molecule (IC50 value: 4.02x10(-24)±0.1 mM) while compound 5 was the most potent anti-oxidant molecule (SC50: 1.31x10(-19)±0.05 mM); both being significantly lower (p<0.05) than the respective positive controls used. The present data showed that the number of phenolic OH together with structural changes influence both the anti-glycation and anti-oxidant observed herein. This study provides for the first time a series of potential template molecules for possible pharmaceutical applications that warrant further investigation as potential anti-glycation and anti-oxidant agents which could be of importance in metabolic diseases including diabetes mellitus.

Schwann Cell Migration Induced by Earthworm Extract via Activation of PAs and MMP2/9 Mediated through ERK1/2 and p38

PubMed Central

Chang, Yung-Ming; Shih, Ying-Ting; Chen, Yueh-Sheng; Liu, Chien-Liang; Fang, Wen-Kuei; Tsai, Chang-Hai; Tsai, Fuu-Jen; Kuo, Wei-Wen; Lai, Tung-Yuan; Huang, Chih-Yang

2011-01-01

The earthworm, which has stasis removal and wound-healing functions, is a widely used Chinese herbal medicine in China. Schwann cell migration is critical for the regeneration of injured nerves. Schwann cells provide an essentially supportive activity for neuron regeneration. However, the molecular migration mechanisms induced by earthworms in Schwann cells remain unclear. Here, we investigate the roles of MAPK (ERK1/2, JNK and p38) pathways for earthworm-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in Schwann cells. Moreover, earthworm induced phosphorylation of ERK1/2 and p38, but not JNK, activate the downstream signaling expression of PAs and MMPs in a time-dependent manner. Earthworm-stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with U0126 and SB203580, resulting in migration and uPA-related signal pathway inhibition. The results were confirmed using small interfering ERK1/2 and p38 RNA. These results demonstrated that earthworms can stimulate Schwann cell migration and up-regulate PAs and MMP2/9 expression mediated through the MAPK pathways, ERK1/2 and p38. Taken together, our data suggests the MAPKs (ERK1/2, p38)-, PAs (uPA, tPA)-, MMP (MMP2, MMP9) signaling pathway of Schwann cells regulated by earthworms might play a major role in Schwann cell migration and nerve regeneration. PMID:19808845

Affinity to bovine serum albumin and anticancer activity of some new water-soluble metal Schiff base complexes

NASA Astrophysics Data System (ADS)

Asadi, Mozaffar; Asadi, Zahra; Zarei, Leila; Sadi, Somaye Barzegar; Amirghofran, Zahra

2014-12-01

Metal Schiff-base complexes show biological activity but they are usually insoluble in water so four new water-soluble metal Schiff base complexes of Na2[M(5-SO3-1,2-salben]; (5-SO3-1,2-salben denoted N,N";-bis(5-sulphosalicyliden)-1,2-diaminobenzylamine and M = Mg, Mn, Cu, Zn) were synthesized and characterized. The formation constants of the metal complexes were determined by UV-Vis absorption spectroscopy. The interaction of these complexes with bovine serum albumin (BSA) was studied by fluorescence spectroscopy. Type of quenching, binding constants, number of binding sites and binding stoichiometries were determined by fluorescence quenching method. The results showed that the mentioned complexes strongly bound to BSA. Thermodynamic parameters indicated that hydrophobic association was the major binding force and that the interaction was entropy driven and enthalpically disfavoured. The displacement experiment showed that these complexes could bind to the subdomain IIA (site I) of albumin. Furthermore the synchronous fluorescence spectra showed that the microenvironment of the tryptophan residues was not apparently changed. Based on the Förster theory of non-radiation energy transfer, the distance between the donor (Trp residues) and the acceptor metal complexes was obtained. The growth inhibitory effect of complexes toward the K562 cancer cell line was measured.

Diet derived phenolic acids regulate osteoblast and adipocyte lineage commitment and differentiation in young mice

USDA-ARS?s Scientific Manuscript database

A blueberry (BB) supplemented diet previously has been shown to significantly stimulate bone formation in rapidly growing male and female rodents. Phenolic acids (PAs) are metabolites derived from polyphenols found in fruits and vegetables as a result of the actions of gut bacteria, and they were fo...

Synthesis, Structural, DNA Binding and Cleavage Studies of Cu(II) Complexes Containing Benzothiazole Cored Schiff Bases.

PubMed

Tejaswi, Somapangu; Kumar, Marri Pradeep; Rambabu, Aveli; Vamsikrishna, Narendrula; Shivaraj

2016-11-01

Novel benzothiazole Schiff bases L 1 [1-((4,6-difluorobenzo[d]thiazol-2-ylimino)methyl) naphthalen-2-ol], L 2 [3-((4,6-difluorobenzo[d]thiazol-2-ylimino) methyl)benzene-1,2-diol], L 3 [2-((4,6-difluorobenzo[d]thiazol-2-ylimino)methyl)-5-methoxyphenol], L 4 [2-((4,6-difluorobenzo[d]thiazol-2-ylimino)methyl)-4-chlorophenol] and their binary Cu(II) complexes were synthesized. The structures of all the compounds have been discussed on the basis of elemental analysis, FT-IR, NMR, UV-Visible, ESI-Mass, TGA, ESR, SEM, powder XRD and magnetic moments. Based on the analytical and spectral data a square planar geometry has been assigned to all complexes in which the Schiff bases act as monobasic bidentate ligands, coordinating through the azomethine nitrogen and phenolic oxygen atom. DNA binding ability of these complexes was studied on CT-DNA by using UV-Vis absorption, fluorescence and viscometry. DNA cleavage ability of the complexes was examined on pBR322 DNA by using gel electrophoresis method. All the DNA binding studies reveal that they are good intercalators. The bioefficacy of the ligands and their complexes was examined against the growth of bacteria and fungi in vitro to evaluate their antimicrobial potential. The screening data revealed that the complexes showed more antimicrobial activity than the corresponding free ligands.

Design, spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases

NASA Astrophysics Data System (ADS)

Hanif, Muhammad; Chohan, Zahid H.

2013-03-01

A new series of three biologically active triazole derived Schiff base ligands L1-L3 have been synthesized in equimolar reaction of 3-amino-1H-1,2,4-triazole with pyrrol-2-carboxaldehyde, 4-bromo-thiophene-2-carboxaldehyde, and 5-iodo-2-hydroxy benzaldehyde. The prepared Schiff bases were used for further complex formation reaction with different metal elements like Co(II), Ni(II), Cu(II) and Zn(II) as chlorides by using a molar ratio of ligand:metal as 2:1. The structure and bonding nature of all the compounds were identified by their physical, spectral and analytical data. All the metal(II) complexes possessed an octahedral geometry except the Cu(II) complexes which showed a distorted octahedral geometry. All the synthesized compounds, were studied for their in vitro antibacterial, and antifungal activities, against four Gram-negative (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and against six fungal strains (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata) by using agar-well diffusion method. It has been shown that all the synthesized compounds showed moderate to significant antibacterial activity against one or more bacterial strains. In vitro Brine Shrimp bioassay was also carried out to investigate the cytotoxic properties of these compounds. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination.

Cytoprotective Effect of Caffeic Acid Phenethyl Ester (CAPE) and Catechol Ring-Fluorinated CAPE Derivatives Against Menadione-Induced Oxidative Stress in Human Endothelial Cells

DTIC Science & Technology

2006-03-31

chlorogenic acid , and rosmari- nic acid did not display any cytoprotective effect in this assay at 15 lM (data not shown). Within the same pas- sage of HUVEC...Cytoprotective effect of caffeic acid phenethyl ester (CAPE) and catechol ring-fluorinated CAPE derivatives against menadione-induced oxidative...accepted 13 March 2006 Available online 31 March 2006 Abstract—Caffeic acid phenethyl ester (CAPE), a natural polyphenolic compound with many

The mechanism of the formation of the hemiaminal and Schiff base from the benzaldehyde and triazole studied by means of the topological analysis of electron localisation function and catastrophe theory

NASA Astrophysics Data System (ADS)

Berski, Slawomir; Zbigniew Ciunik, Leszek

2015-04-01

The mechanisms of reaction of benzaldehyde (ald) with 4-amine-4H-1,2,4-triazole (4at), leading to Schiff base (Sch) and water, were investigated using topological analysis of the electron localisation function and catastrophe theory. Two reactions (synthesis of hemiaminal and synthesis of Schiff base) are represented by one catastrophe sequence: ald+4at: 1-14-[FF†F†FFTS1FF†F†FF†F†CF†]-2-9-[C†FFTS3F†F†FFF]-0:Sch+H2O with only fold (F) and cusp (C) catastrophes. The first reaction, in which a molecule of the hemiaminal is formed, consists of 14 steps separated by 13 catastrophes. The mechanism is non-concerted. The covalent bond C-N is formed after the formation of the O-H bond is terminated. The Schiff base formation through the water molecule elimination in the second reaction requires nine steps with eight catastrophes. The mechanism is non-concerted because first the C-O bond is broken and then the proton transfer occurs that results in the O-H bond creation.

Effects of structures of bidentate Schiff base type bonded-ligands derived from benzaldehyde on the photoluminescence performance of polymer-rare earth complexes.

PubMed

Gao, Baojiao; Zhang, Liqin; Zhang, Dandan

2018-02-07

Two kinds of bidentate Schiff base ligands derived from benzaldehyde, benzaldehyde/m-aminophenol (BAMA) type and benzaldehyde/glutamic acid (BAGL) type ligands, were synchronously synthesized and bonded on the backbone of polysulfone (PSF) through molecular design and by polymer reactions, and two functional polymers, PSF-BAMA and PSF-BAGL, were obtained. Then two series of novel luminescent Schiff base-type polymer-rare earth complexes were prepared via coordination reactions. In this work, the effects of the structures of the bonded ligands on the photoluminescence performance of the complexes were investigated in detail, and for the different photophysical properties of the prepared complexes, relevant theoretical explanations were given. The experimental results show that the bonded ligand BAMA can strongly sensitize the fluorescence emission of Eu(iii) ions, and the binary complex PSF-(BAMA) 3 -Eu(iii) emits strong red fluorescence under UV light. The reason for this lies in the fact that a larger conjugate π-bond system is contained in the structure of BAMA, and so the triplet state of BAMA can be matched with the resonant energy level of the Eu(iii) ion. While the bonded ligand BAGL can effectively sensitize the fluorescence emission of Tb(iii) ions, the binary complex PSF-(BAGL) 3 -Tb(iii) exhibits very strong green fluorescence under UV light. The reason is that a smaller conjugate π-bond system is contained in the structure of BAGL and there is a good energy level matching between the triplet state of BAGL and the resonant energy level of the Tb(iii) ion. The fluorescence intensities of the two ternary complexes, PSF-(BAMA) 3 -Eu(iii)-(Phen) 1 (phenanthroline, Phen) and PSF-(BAGL) 3 -Tb(iii)-(Phen) 1 , are much stronger than that of the corresponding binary complex because Phen as the second ligand has two effects, the effect of synergistic coordination with the first ligand and the effect of replacing the coordinated water around the central ion, and

New cobalt(II) and nickel(II) complexes of benzyl carbazate Schiff bases: Syntheses, crystal structures, in vitro DNA and HSA binding studies.

PubMed

Nithya, Palanivelu; Helena, Sannasi; Simpson, Jim; Ilanchelian, Malaichamy; Muthusankar, Aathi; Govindarajan, Subbiah

2016-12-01

In the present study, new Schiff base complexes with the composition [M(NCS) 2 (L1) 2 ]·nH 2 O, where M=Co (n=0) (1) and Ni (n=2) (2); [M(NCS) 2 (L2) 2 ], M=Co (3) and Ni (4) as well as [M(NCS) 2 (L3) 2 ], M=Co (5) and Ni (6); (L1=benzyl 2-(propan-2-ylidene)hydrazinecarboxylate, L2=benzyl 2-(butan-2-ylidene)hydrazinecarboxylate and L3=benzyl 2-(pentan-3-ylidene)hydrazinecarboxylate) have been synthesized by a template method. The complexes were characterised by analytical methods, spectroscopic studies, thermal and X-ray diffraction techniques. The structures of all the complexes explore that the metal(II) cation has a trans-planar coordination environment, the monomeric units containing a six-coordinated metal center in octahedral geometry with N-bound isothiocyanate anions coordinated as terminal ligands. Furthermore, the binding of the two Schiff base ligands to the metal centers involves the azomethine nitrogen and the carbonyl oxygen in mutually trans configuration. The binding interactions of all the complexes with Calf thymus-deoxyribonucleic acid (CT-DNA) and human serum albumin (HSA) have been investigated using absorption and emission spectral techniques. The CT-DNA binding properties of these complexes reveal that they bind to CT-DNA through a partial intercalation mode and the binding constant values were calculated using the absorption and emission spectral data. The binding constant values (~10×10 6 moldm -3 ) indicate strong binding of metal complexes with CT-DNA. HSA binding interaction studies showed that the cobalt and nickel complexes can quench the intrinsic fluorescence of HSA through static quenching process. Also, molecular docking studies were supported out to apprehend the binding interactions of these complexes with DNA and HSA which offer new understandings into the experimental model observations. Copyright © 2016 Elsevier B.V. All rights reserved.

Ru(II) complexes of N 4 and N 2O 2 macrocyclic Schiff base ligands: Their antibacterial and antifungal studies

NASA Astrophysics Data System (ADS)

Shanker, Kanne; Rohini, Rondla; Ravinder, Vadde; Reddy, P. Muralidhar; Ho, Yen-Peng

2009-07-01

Reactions of [RuCl 2(DMSO) 4] with some of the biologically active macrocyclic Schiff base ligands containing N 4 and N 2O 2 donor group yielded a number of stable complexes, effecting complete displacement of DMSO groups from the complex. The interaction of tetradentate ligand with [RuCl 2(DMSO) 4] gave neutral complexes of the type [RuCl 2(L)] [where L = tetradentate macrocyclic ligand]. These complexes were characterized by elemental, IR, 1H, 13C NMR, mass, electronic, thermal, molar conductance and magnetic susceptibility measurements. An octahedral geometry has been proposed for all complexes. All the macrocycles and macrocyclic Ru(II) complexes along with existing antibacterial drugs were screened for antibacterial activity against Gram +ve ( Bacillus subtilis, Staphylococcus aureus) and Gram -ve ( Escherichia coli, Klebsiella pneumonia) bacteria. All these compounds were found to be more active when compared to streptomycin and ampicillin. The representative macrocyclic Schiff bases and their complexes were also tested in vitro to evaluate their activity against fungi, namely, Aspergillus flavus and Fusarium species.

From Mesocates to Helicates: Structural, Magnetic and Chiro-Optical Studies on Nickel(II) Supramolecular Assemblies Derived from Tetradentate Schiff Bases.

PubMed

Mayans, Júlia; Font-Bardia, Mercè; Di Bari, Lorenzo; Arrico, Lorenzo; Zinna, Francesco; Pescitelli, Gennaro; Escuer, Albert

2018-05-28

The systematic reactions of a family of tetradentate pyridyl/imine and quinolyl/imine racemic or enantiopure Schiff bases with Ni(NO 3 ) 2 or Ni(ClO 4 ) 2 in the presence of sodium azide yielded, as a function of the starting racemic, chiral or achiral base, a set of chiral, meso or achiral complexes. In all cases, the compounds consist of two Ni II cations linked by a double azido bridge in its end-on coordination mode. All the dimers exhibit a mesocate supramolecular structure and one of them, the unprecedented mix of helicate and mesocate in 2:1 ratio. The transition from mesocate to helicate conformation has been reached by tuning the flexibility of the central spacers of the Schiff bases and the size of the substituents. Electronic circular dichroism (ECD) studies have been performed for two pairs of enantiomers and interpreted by means of DFT calculations. Susceptibility measurements show a ferromagnetic coupling between the Ni II cations mediated by the end-on azido bridges. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A history of PAs in the US Public Health Service.

PubMed

McKinnon, Mark F; Elizondo, Epifanio; Bonfiglio, Susan M; Hunter-Buskey, Robin N; Placide, Frances P; Bunnell, Rebecca A

2016-12-01

Since 1798, the men and women of the Commissioned Corps of the US Public Health Service (USPHS), one of the seven US uniformed services, have served on the front lines of public health. Two hundred years after the start of the USPHS, the first physician assistant (PA) entered the service to carry on the tradition of protecting, promoting, and advancing the health and safety of the nation. These dedicated clinicians are involved in healthcare delivery to underserved and vulnerable populations, disease control and prevention, biomedical research, food and drug regulation, and national and international response efforts for natural and man-made disasters. This article describes how PAs in the Commissioned Corps of the USPHS have impacted the health and safety of not only the United States but also the international community.

Response surface optimized peroxyoxalate chemiluminescence of octahydro-Schiff base derivative as new luminophor and study of the quenching effect of some cations, amino acids and cholesterol.

PubMed

Yeganeh Faal, Ali; Jamalyan, Bahare; Bordbar, Maryam; Shayeste, Tavakol Heidary; Salavati-Niasari, Masoud

2014-12-01

We report the first detailed study of the characteristics of an octahydro-Schiff base derivative as a new luminophor in the peroxyoxalate chemiluminescence (POCL) system. The effect of reagents on this new POCL system was investigated. In addition, the response surface methodology was used for evaluating the relative significance of variables in this POCL system, establishing models and determining optimal conditions. The quenching effect of some cations and compounds such as Cu(2+), Fe(3+), Hg(2+), imidazole, histidine and cholesterol on an optimized POCL reaction were studied. The dynamic ranges were up to approximaterly 100 and 175 × 10(-6) M for Cu(2+) and cholesterol respectively. The detection limits were 3.3 × 10(-6) m and 2.58 × 10(-6) m for Cu(2+) and histidine, respectively. In all cases the relative standard deviations were 4-5% (n = 4). Copyright © 2014 John Wiley & Sons, Ltd.

Programmable Logic Device (PLD) Design Description for the Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio System (STRS) Radio

NASA Technical Reports Server (NTRS)

Shalkhauser, Mary Jo W.

2017-01-01

The Space Telecommunications Radio System (STRS) provides a common, consistent framework for software defined radios (SDRs) to abstract the application software from the radio platform hardware. The STRS standard aims to reduce the cost and risk of using complex, configurable and reprogrammable radio systems across NASA missions. To promote the use of the STRS architecture for future NASA advanced exploration missions, NASA Glenn Research Center (GRC) developed an STRS compliant SDR on a radio platform used by the Advance Exploration System program at the Johnson Space Center (JSC) in their Integrated Power, Avionics, and Software (iPAS) laboratory. At the conclusion of the development, the software and hardware description language (HDL) code was delivered to JSC for their use in their iPAS test bed to get hands-on experience with the STRS standard, and for development of their own STRS Waveforms on the now STRS compliant platform.The iPAS STRS Radio was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RIACS) platform, currently being used for radio development at JSC. The platform consists of a Xilinx ML605 Virtex-6 FPGA board, an Analog Devices FMCOMMS1-EBZ RF transceiver board, and an Embedded PC (Axiomtek eBox 620-110-FL) running the Ubuntu 12.4 operating system. Figure 1 shows the RIACS platform hardware. The result of this development is a very low cost STRS compliant platform that can be used for waveform developments for multiple applications.The purpose of this document is to describe the design of the HDL code for the FPGA portion of the iPAS STRS Radio particularly the design of the FPGA wrapper and the test waveform.

Control Mechanisms of Photoisomerization in Protonated Schiff Bases.

PubMed

Vuković, Lela; Burmeister, Carl F; Král, Petr; Groenhof, Gerrit

2013-03-21

We performed ab initio excited-state molecular dynamics simulations of a gas-phase photoexcited protonated Schiff base (C1-N2═C3-C4═C5-C6) to search for control mechanisms of its photoisomerization. The excited molecule twists by ∼90° around either the N2C3 bond or the C4C5 bond and relaxes to the ground electronic state through a conical intersection with either a trans or cis outcome. We show that a large initial distortion of several dihedral angles and a specific normal vibrational mode combining pyramidalization and double-bond twisting can lead to a preferential rotation of atoms around the C4C5 bond. We also show that selective pretwisting of several dihedral angles in the initial ground state thermal ensemble (by analogy to a protein pocket) can significantly increase the fraction of photoreactive (cis → trans) trajectories. We demonstrate that new ensembles with higher degrees of control over the photoisomerization reaction can be obtained by a computational directed evolution approach on the ensembles of molecules with the pretwisted geometries.

Mössbauer study of novel iron(II) complexes synthesized with Schiff bases

NASA Astrophysics Data System (ADS)

Várhelyi, Cs.; Lengyel, A.; Homonnay, Z.; Szalay, R.; Pokol, Gy.; Szilágyi, I.-M.; Huszthy, P.; Papp, J.; Goga, F.; Golban, L.-M.; Várhelyi, M.; Tomoaia-Cotisel, M.; Szőke, Á.; Kuzmann, E.

2017-11-01

Novel [Fe(4-benzyl-2-hydroxyphenyl-propylidene)2ethylene-diamine], and [Fe (2,4,6-trihydroxy-benzyl-4-metoxiphenyl-methylidene)2ethylene-diamine] complexes were synthesized by reacting FeII salt with the indicated Schiff-base ligands. The compounds were characterized by57Fe Mössbauer spectroscopy, FTIR, UV-VIS, TG-DTA-DTG, MS, AFM, XRD, cyclic voltammetry and biological activity measurements. 295 K and 78 K Mössbauer spectra revealed that iron is dominantly in high spin FeII state in both complexes while simultaneously a minor low spin FeII was also present in both complexes, furthermore a minor high spin FeIII was observed in [Fe(2,4,6-trihydroxy-benzyl-4-metoxiphenyl- methylidene) 2ethylene-diamine], too.

Ferroelectric Liquid Crystals: Synthesis and Thermal Behavior of Optically Active, Three-Ring Schiff Bases and Salicylaldimines.

PubMed

Veerabhadraswamy, Bhyranalyar N; Rao, Doddamane S Shankar; Yelamaggad, Channabasaveshwar V

2018-04-16

The chiral ferroelectric smectic C (SmC*) phase, characterized by a helical superstructure, has been well exploited in developing high-resolution microdisplays that have been effectively employed in the fabrication of a wide varieties of portable devices. Although, an overwhelming number of optically active (chiral) liquid crystals (LCs) exhibiting a SmC* phase have been designed and synthesized, the search for new systems continues so as to realize mesogens capable of meeting technical necessities and specifications for their end-use. In continuation of our research work in this direction, herein we report the design, synthesis, and thermal behavior of twenty new optically active, three-ring calamitic LCs belonging to four series. The first two series comprise five pairs of enantiomeric Schiff bases whereas the other two series are composed of five pairs of enantiomeric salicylaldimines. In each pair of optical isomers, the configuration of a chiral center in one stereoisomer is opposite to that of the analogous center in the other isomer as they are derived from (3 S)-3,7-dimethyloctyloxy and (3 R)-3,7-dimethyloctyloxy tails. To probe the structure-property correlations in each series, the length of the n-alkoxy tail situated at the other end of the mesogens has been varied from n-octyloxy to n-dodecyloxy. The measurement of optical activity of these chiral mesogens was carried out by recording their specific rotations. As expected, enantiomers rotate plane polarized light in the opposite direction but by the same magnitude. The thermal behavior of the compounds was established by using a combination of optical polarizing microscopy, differential scanning calorimetry, and powder X-ray diffraction. These complementary techniques demonstrate the existence of the expected, thermodynamically stable, chiral smectic C (SmC*) LC phase besides blue phase I/II (BPI or BPII) and chiral nematic (N*) phase. However, as noted in our previous analogous study, the vast

Tetradentate Schiff base platinum(II) complexes as new class of phosphorescent materials for high-efficiency and white-light electroluminescent devices.

PubMed

Che, Chi-Ming; Chan, Siu-Chung; Xiang, Hai-Feng; Chan, Michael C W; Liu, Yu; Wang, Yue

2004-07-07

The capabilities of readily prepared and sublimable Pt(II) Schiff base triplet emitters as OLED dopants have been examined; maximum luminous and power efficiencies and luminance of 31 cd A(-1), 14 lm W(-1), and 23,000 cd m(-2), respectively, and white EL (CIE: 0.33, 0.35) by simultaneous host/dopant emission, have been achieved.

Steric effects in the design of Co-Schiff base complexes for the catalytic oxidation of lignin models to para-benzoquinones

Treesearch

Berenger Biannic; Joseph J. Bozell; Thomas Elder

2014-01-01

New Co-Schiff base complexes that incorporate a sterically hindered ligand and an intramolecular bulky piperazine base in close proximity to the Co center are synthesized. Their utility as catalysts for the oxidation of para-substituted lignin model phenols with molecular oxygen is examined. Syringyl and guaiacyl alcohol, as models of S and G units in lignin, are...

Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity

NASA Astrophysics Data System (ADS)

Şahin, Mustafa; Koçak, Nuriye; Erdenay, Damla; Arslan, Uğur

2013-02-01

New asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, 1H NMR, 13C NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL2A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain.

Nuclear Glycogen Inclusions in Canine Parietal Cells.

PubMed

Silvestri, S; Lepri, E; Dall'Aglio, C; Marchesi, M C; Vitellozzi, G

2017-05-01

Nuclear glycogen inclusions occur infrequently in pathologic conditions but also in normal human and animal tissues. Their function or significance is unclear. To the best of the authors' knowledge, no reports of nuclear glycogen inclusions in canine parietal cells exist. After initial observations of nuclear inclusions/pseudoinclusions during routine histopathology, the authors retrospectively examined samples of gastric mucosa from dogs presenting with gastrointestinal signs for the presence of intranuclear inclusions/pseudoinclusions and determined their composition using histologic and electron-microscopic methods. In 24 of 108 cases (22%), the authors observed various numbers of intranuclear inclusions/pseudoinclusions within scattered parietal cells. Nuclei were characterized by marked karyomegaly and chromatin margination around a central optically empty or slightly eosinophilic area. The intranuclear inclusions/pseudoinclusions stained positive with periodic acid-Schiff (PAS) and were diastase sensitive, consistent with glycogen. Several PAS-positive/diastase-sensitive sections were further examined by transmission electron microscopy, also using periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining to identify polysaccharides. Ultrastructurally, the nuclear inclusions were composed of electron-dense particles that were not membrane bound, without evidence of nuclear membrane invaginations or cytoplasmic organelles in the nuclei, and positive staining with PA-TCH-SP, confirming a glycogen composition. No cytoplasmic glycogen deposits were observed, suggesting that the intranuclear glycogen inclusions were probably synthesized in loco. Nuclear glycogen inclusions were not associated with gastritis or colonization by Helicobacter-like organisms ( P > .05). Our findings suggest that nuclear glycogen inclusions in canine parietal cells could be an incidental finding. Nevertheless, since nuclear glycogen is present in several pathologic

H2O2 production rate in Lactobacillus johnsonii is modulated via the interplay of a heterodimeric flavin oxidoreductase with a soluble 28 Kd PAS domain containing protein

PubMed Central

Valladares, Ricardo B.; Graves, Christina; Wright, Kaitlyn; Gardner, Christopher L.; Lorca, Graciela L.; Gonzalez, Claudio F.

2015-01-01

Host and commensals crosstalk, mediated by reactive oxygen species (ROS), has triggered a growing scientific interest to understand the mechanisms governing such interaction. However, the majority of the scientific studies published do not evaluate the ROS production by commensals bacteria. In this context we recently showed that Lactobacillus johnsonii N6.2, a strain of probiotic value, modulates the activity of the critical enzymes 2,3-indoleamine dioxygenase via H2O2 production. L. johnsonii N6.2 by decreasing IDO activity, is able to modify the tryptophan/kynurenine ratio in the host blood with further systemic consequences. Understanding the mechanisms of H2O2 production is critical to predict the probiotic value of these strains and to optimize bacterial biomass production in industrial processes. We performed a transcriptome analysis to identify genes differentially expressed in L. johnsonii N6.2 cells collected from cultures grown under different aeration conditions. Herein we described the biochemical characteristics of a heterodimeric FMN reductase (FRedA/B) whose in vitro activity is controlled by LjPAS protein with a typical Per-Arnst-Sim (PAS) sensor domain. Interestingly, LjPAS is fused to the FMN reductase domains in other lactobacillaceae. In L. johnsonii, LjPAS is encoded by an independent gene which expression is repressed under anaerobic conditions (>3 fold). Purified LjPAS was able to slow down the FRedA/B initial activity rate when the holoenzyme precursors (FredA, FredB, and FMN) were mixed in vitro. Altogether the results obtained suggest that LjPAS module regulates the H2O2 production helping the cells to minimize oxidative stress in response to environmental conditions. PMID:26236298

H2O2 production rate in Lactobacillus johnsonii is modulated via the interplay of a heterodimeric flavin oxidoreductase with a soluble 28 Kd PAS domain containing protein.

PubMed

Valladares, Ricardo B; Graves, Christina; Wright, Kaitlyn; Gardner, Christopher L; Lorca, Graciela L; Gonzalez, Claudio F

2015-01-01

Host and commensals crosstalk, mediated by reactive oxygen species (ROS), has triggered a growing scientific interest to understand the mechanisms governing such interaction. However, the majority of the scientific studies published do not evaluate the ROS production by commensals bacteria. In this context we recently showed that Lactobacillus johnsonii N6.2, a strain of probiotic value, modulates the activity of the critical enzymes 2,3-indoleamine dioxygenase via H2O2 production. L. johnsonii N6.2 by decreasing IDO activity, is able to modify the tryptophan/kynurenine ratio in the host blood with further systemic consequences. Understanding the mechanisms of H2O2 production is critical to predict the probiotic value of these strains and to optimize bacterial biomass production in industrial processes. We performed a transcriptome analysis to identify genes differentially expressed in L. johnsonii N6.2 cells collected from cultures grown under different aeration conditions. Herein we described the biochemical characteristics of a heterodimeric FMN reductase (FRedA/B) whose in vitro activity is controlled by LjPAS protein with a typical Per-Arnst-Sim (PAS) sensor domain. Interestingly, LjPAS is fused to the FMN reductase domains in other lactobacillaceae. In L. johnsonii, LjPAS is encoded by an independent gene which expression is repressed under anaerobic conditions (>3 fold). Purified LjPAS was able to slow down the FRedA/B initial activity rate when the holoenzyme precursors (FredA, FredB, and FMN) were mixed in vitro. Altogether the results obtained suggest that LjPAS module regulates the H2O2 production helping the cells to minimize oxidative stress in response to environmental conditions.

Synthesis, characterization, DFT calculations and biological studies of Mn(II), Fe(II), Co(II) and Cd(II) complexes based on a tetradentate ONNO donor Schiff base ligand

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Laila H.; Ismail, Nabawia M.; Ismael, Mohamed; Abu-Dief, Ahmed M.; Ahmed, Ebtehal Abdel-Hameed

2017-04-01

This study highlights synthesis and characterization of a tetradentate ONNO Schiff base ligand namely (1, 1‧- (pyridine-2, 3-dimethyliminomethyl) naphthalene-2, 2‧-diol) and hereafter denotes as "HNDAP″ and selected metal complexes including Mn(II), Fe(II), Co(II) and Cd(II) as a central metal. HNDAP was synthesized from 1:2 M ratio condensation of 2, 3-diaminopyridine and 2- hydroxy-1-naphthaldhyde, respectively. The stoichiometric ratios of the prepared complexes were estimated using complementary techniques such as; elemental analyses (-C, H, N), FT-IR, magnetic measurements and molar conductivity. Furthermore, their physicochemical studies were carried out using thermal TGA, DTA and kinetic-thermodynamic studies along with DFT calculations. The results of elemental analyses showed that these complexes are present in a 1:1 metal-to- ligand molar ratio. Moreover, the magnetic susceptibilities values at room temperature revealed that Mn(II), Fe(II) and Co(II) complexes are paramagnetic in nature and have an octahedral (Oh) geometry. In contrast, Cd(II) is diamagnetic and stabilizes in square planar sites. The molar conductivity measurements indicated that all complexes are nonelectrolytes in dimethyl formamide. Spectral data suggested that the ligand is as tetradentate and coordinated with Co(II) ion through two phenolic OH and two azomethine nitrogen. However, for Mn(II), Fe(II) and Cd(II) complexes, the coordination occurred through two phenolic oxygen and two azomethine nitrogen with deprotonation of OH groups. The proposed chemical structures have been validated by quantum mechanics calculations. Antimicrobial activities of both the HNDAP Schiff base ligand and its metal complexes were tested against strains of Gram (-ve) E. coli and Gram (+ve) B. subtilis and S. aureus bacteria and C. albicans, A. flavus and T. rubrum fungi. All the prepared compounds showed good results of inhibition against the selected pathogenic microorganisms. The investigated

6-Mercaptopurine reduces cytokine and Muc5ac expression involving inhibition of NFκB activation in airway epithelial cells.

PubMed

Kurakula, Kondababu; Hamers, Anouk A; van Loenen, Pieter; de Vries, Carlie J M

2015-06-19

Mucus hypersecretion and excessive cytokine synthesis is associated with many of the pathologic features of chronic airway diseases such as asthma. 6-Mercaptopurine (6-MP) is an immunosuppressive drug that is widely used in several inflammatory disorders. Although 6-MP has been used to treat asthma, its function and mechanism of action in airway epithelial cells is unknown. Confluent NCI-H292 and MLE-12 epithelial cells were pretreated with 6-MP followed by stimulation with TNFα or PMA. mRNA levels of cytokines and mucins were measured by RT-PCR. Western blot analysis was performed to assess the phosphorylation of IκBα and luciferase assays were performed using an NFκB reporter plasmid to determine NFκB activity. Periodic Acid Schiff staining was used to assess the production of mucus. 6-MP displayed no effect on cell viability up to a concentration of 15 μM. RT-PCR analysis showed that 6-MP significantly reduces TNFα- and PMA-induced expression of several proinflammatory cytokines in NCI-H292 and MLE-12 cells. Consistent with this, we demonstrated that 6-MP strongly inhibits TNFα-induced phosphorylation of IκBα and thus attenuates NFκB luciferase reporter activity. In addition, 6-MP decreases Rac1 activity in MLE-12 cells. 6-MP down-regulates gene expression of the mucin Muc5ac, but not Muc2, through inhibition of activation of the NFκB pathway. Furthermore, PMA- and TNFα-induced mucus production, as visualized by Periodic Acid Schiff (PAS) staining, is decreased by 6-MP. Our data demonstrate that 6-MP inhibits Muc5ac gene expression and mucus production in airway epithelial cells through inhibition of the NFκB pathway, and 6-MP may represent a novel therapeutic target for mucus hypersecretion in airway diseases.

Chiral halogenated Schiff base compounds: green synthesis, anticancer activity and DNA-binding study

NASA Astrophysics Data System (ADS)

Ariyaeifar, Mahnaz; Amiri Rudbari, Hadi; Sahihi, Mehdi; Kazemi, Zahra; Kajani, Abolghasem Abbasi; Zali-Boeini, Hassan; Kordestani, Nazanin; Bruno, Giuseppe; Gharaghani, Sajjad

2018-06-01

Eight enantiomerically pure halogenated Schiff base compounds were synthesized by reaction of halogenated salicylaldehydes with 3-Amino-1,2-propanediol (R or S) in water as green solvent at ambient temperature. All compounds were characterized by elemental analyses, NMR (1H and 13C), circular dichroism (CD) and FT-IR spectroscopy. FS-DNA binding studies of these compounds carried out by fluorescence quenching and UV-vis spectroscopy. The obtained results revealed that the ligands bind to DNA as: (Rsbnd ClBr) > (Rsbnd Cl2) > (Rsbnd Br2) > (Rsbnd I2) and (Ssbnd ClBr) > (Ssbnd Cl2) > (Ssbnd Br2) > (Ssbnd I2), indicating the effect of halogen on binding constant. In addition, DNA-binding constant of the Ssbnd and R-enantiomers are different from each other. The ligands can form halogen bonds with DNA that were confirmed by molecular docking. This method was also measured the bond distances and bond angles. The study of obtained data can have concluded that binding affinity of the ligands to DNA depends on strength of halogen bonds. The potential anticancer activity of ligands were also evaluated on MCF-7 and HeLa cancer cell lines by using MTT assay. The results showed that the anticancer activity and FS-DNA interaction is significantly dependent on the stereoisomers of Schiff base compounds as R-enantiomers displayed significantly higher activity than S-enantiomers. The molecular docking was also used to illustrate the specific DNA-binding of synthesized compounds and groove binding mode of DNA interaction was proposed for them. In addition, molecular docking results indicated that there are three types of bonds (Hsbnd and X-bond and hX-bond) between synthesized compounds and base pairs of DNA.

Preparation, characterization and biological activity of novel metal-NNNN donor Schiff base complexes

NASA Astrophysics Data System (ADS)

Mohamed, Gehad G.; Omar, M. M.; Ibrahim, Amr A.

2010-02-01

Novel Schiff base (H 2L) ligand is prepared via condensation of benzil and triethylenetetraamine. The ligand is characterized based on elemental analysis, mass, IR and 1H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance, and thermal analyses (TG, DTG and DTA). 1:1 [M]:[H 2L] complexes are found from the elemental analyses data having the formulae [M(H 2L)Cl 2]· yH 2O (M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II)), [Fe(H 2L)Cl 2]Cl·H 2O, [Th(H 2L)Cl 2]Cl 2·3H 2O and [UO 2(H 2L)](CH 3COO) 2·2H 2O. The metal chelates are found to be non-electrolytes except Fe(III), Th(IV) and UO 2(II) complexes are electrolytes. IR spectra show that H 2L is coordinated to the metal ions in a neutral tetradentate manner with 4Ns donor sites of the two azomethine N and two NH groups. The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats-Redfern method. The ligand (H 2L), in comparison to its metal complexes, is screened for its antibacterial activity. The activity data show that the metal complexes have antibacterial activity more than the parent Schiff base ligand and cefepime standard against one or more bacterial species.

A novel signal transduction protein: Combination of solute binding and tandem PAS-like sensor domains in one polypeptide chain: Periplasmic Ligand Binding Protein Dret_0059

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, R.; Wilton, R.; Cuff, M. E.

We report the structural and biochemical characterization of a novel periplasmic ligand-binding protein, Dret_0059, from Desulfohalobium retbaense DSM 5692, an organism isolated from the Salt Lake Retba in Senegal. The structure of the protein consists of a unique combination of a periplasmic solute binding protein (SBP) domain at the N-terminal and a tandem PAS-like sensor domain at the C-terminal region. SBP domains are found ubiquitously and their best known function is in solute transport across membranes. PAS-like sensor domains are commonly found in signal transduction proteins. These domains are widely observed as parts of many protein architectures and complexes butmore » have not been observed previously within the same polypeptide chain. In the structure of Dret_0059, a ketoleucine moiety is bound to the SBP, whereas a cytosine molecule is bound in the distal PAS-like domain of the tandem PAS-like domain. Differential scanning flourimetry support the binding of ligands observed in the crystal structure. There is significant interaction between the SBP and tandem PAS-like domains, and it is possible that the binding of one ligand could have an effect on the binding of the other. We uncovered three other proteins with this structural architecture in the non-redundant sequence data base, and predict that they too bind the same substrates. The genomic context of this protein did not offer any clues for its function. We did not find any biological process in which the two observed ligands are coupled. The protein Dret_0059 could be involved in either signal transduction or solute transport.« less

Spectroscopic characterization of metal complexes of novel Schiff base. Synthesis, thermal and biological activity studies

NASA Astrophysics Data System (ADS)

Omar, M. M.; Mohamed, Gehad G.; Ibrahim, Amr A.

2009-07-01

Novel Schiff base (HL) ligand is prepared via condensation of 4-aminoantipyrine and 2-aminobenzoic acid. The ligand is characterized based on elemental analysis, mass, IR and 1H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TGA, DrTGA and DTA). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a uninegatively tridentate manner with NNO donor sites of the azomethine N, amino N and deprotonated caroxylic-O. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral. The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, ΔH*, ΔS* and ΔG* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligands, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia Coli, Pseudomonas aeruginosa, Staphylococcus Pyogones and Fungi (Candida). The activity data show that the metal complexes to be more potent/antibacterial than the parent Shciff base ligand against one or more bacterial species.

New approach for the quantification of metallic species in healthcare products based on optical switching of a Schiff base possessing ONO donor set.

PubMed

Singh, Jaswant; Parkash, Jyoti; Kaur, Varinder; Singh, Raghubir

2017-10-05

A new method is reported for the quantification of some metallic components of healthcare products utilizing a Schiff base chelator derived from 2-hydroxyacetophenone and ethanolamine. The Schiff base chelator recognizes some metallic species such as iron, copper and zinc (important components of some healthcare products), and cadmium (common contaminant in healthcare products) giving colorimetric/fluorimetric response. It coordinates with Fe 2+ /Fe 3+ and Cu 2+ ions via ONO donor set and switches the colour to bright red, green and orange, respectively. Similarly, it switches 'ON' a fluorometric response when coordinates with Zn 2+ and Cd 2+ ions. In the present approach, detailed studies on the colorimetric and fluorimetric response of ONO Schiff base is investigated in detail. The Job plot for the complexation of ONO switch with various metal ions suggested formation of 1:1 (metal-chelator) complex with Fe 2+ , Fe 3+ , and Cu 2+ while 1:2 (metal-chelator) for Zn 2+ and Cd 2+ ions. The limit of detection, limit of quantification are 6.73, 18.0, 25.0, 0.65, 1.10μM and 27.0, 72.0, 100.0, 2.60 and 4.40μM for Fe 2+ , Fe 3+ , Cu 2+ , Zn 2+ and Cd 2+ ions, respectively. Under the optimized conditions, chelator was used for the quantification of important metals present in healthcare products via direct dissolution and furnace treatment during sample preparation. The results were found precise and accurate for both sample preparation techniques using the developed method. Copyright © 2017 Elsevier B.V. All rights reserved.

47 CFR Appendix B to Part 64 - Priority Access Service (PAS) for National Security and Emergency Preparedness (NSEP)

Code of Federal Regulations, 2010 CFR

2010-10-01

... leadership; (iii) Disaster shelter coordination and management; and (iv) Critical Disaster Field Office... telecommunications management and response functions during emergency/disaster situations. 3. Initiate PAS requests... priorities, priority one being the highest. The five priority levels are: 1. Executive Leadership and Policy...

Ultrasound-assisted extraction and preliminary purification of proanthocyanidins and chlorogenic acid from almond (Prunus dulcis) skin.

PubMed

Ma, Xue; Zhou, Xin-Yu; Qiang, Qian-Qian; Zhang, Zhi-Qi

2014-07-01

An aqueous solution of polyethylene glycol (PEG) as a green solvent was employed for the first time to develop the ultrasound-assisted extraction of proanthocyanidins (PA) and chlorogenic acid (CA) from almond skin. The optimized extraction parameters were determined based on response surface methodology, and corresponded to an ultrasound power of 120 W, a liquid-to-solid ratio of 20:1 (mL/g), and a PEG concentration of 50% (v/v). Under these optimized conditions, the extraction yields of PAs and CA from almond skin were 32.68 ± 0.22 and 16.01 ± 0.19 mg/g, respectively. Compared with organic solvent extraction, PEG solution extraction produced higher yields. Different macroporous resins were compared for their performance in purifying PAs and CA from almond skin extract. Static adsorption/desorption experimental results demonstrated that AB-8 resin exhibits excellent purification performance at pH 4. Under the optimized dynamic adsorption/desorption conditions on the AB-8 column, the total recovery of purification for PAs and CA was 80.67%. The total content of PAs and CA in the preliminarily purified extract was 89.17% (with respective contents of 60.90 and 28.27%). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, Characterization and the Corrosion Inhibition Study of Two Schiff Base Ligands Derived From Urea and Thiourea and Their Complexes with Cu(II) and Hg(II) Ions

NASA Astrophysics Data System (ADS)

Alwan, Wasan Mohammed

2018-05-01

The research includes synthesis of [L1] and [L2] Schiff base ligands by the reaction of vanillin with urea and thiourea respectively in 2:1 mol ratio. The two ligands were reacted with CuII ion in 1:2 mol ratio and HgII ion in 1:1 mol ratio. The prepared compounds have been identified by FTIR, U.V-Vis, 1H-NMR (L1, L2 and HgII complex) spectroscopies, microelemental analysis (C.H.N.S), magnetic susceptibility measurements, atomic absorption, chloride content along with conductivity and melting point measurements. According to applied characterization methods, the proposed general formulas of CuII and HgII complexes were [Cu2LnCl4] and [HgLnCl]Cl, respectively, (where n = 1, 2). The ability of corrosion inhibition with two ligands and their cupper complexes has been studied in diluted hydrochloric acid media.

Spectral and thermal study of the ternary complexes of nickel with sulfasalazine and some amino acids

NASA Astrophysics Data System (ADS)

Soliman, Ahmed A.

2006-12-01

The ternary complexes of Ni(II) with sulfasalazine (H 3SS) as a primary ligand and alanine (ala), aspartic acid (asp), histidene (hist), methionine (meth) and serine (ser) amino acids as secondary ligands have been synthesized. Characterization of the complexes was based on elemental analyses, IR, UV-vis, mass spectra, magnetic moment and thermal analysis (TG). The isolated complexes were found to have the general formula [M(HSS)(AA)]4H 2O (AA = ala, asp, hist, meth, or ser amino acid) where nickel is tetra-coordinated. The thermal stability of the complexes was studied and the weight losses for the decomposition of the complexes were calculated and correlated with the mass fragmentation pattern. In most cases, the amino acid moiety is removed along with the Schiff base moiety leaving NiO as a metallic residue. The metallic residue was confirmed by powder XRD measurements.

PAs reduce rounding interruptions in the pediatric intensive care unit.

PubMed

Hascall, Rebecca L; Perkins, R Serene; Kmiecik, Lauren; Gupta, Priya R; Shelak, Carolyn F; Demirel, Shaban; Buchholz, Mark T

2018-06-01

We investigated the proportion of encounters that were interrupted during family-centered rounds in the pediatric intensive care unit (PICU) to determine whether the use of a physician assistant (PA) significantly affected the proportion of interrupted encounters. We evaluated 2,657 rounding encounters in our 24-bed regional referral unit. The duration of each rounding encounter and total rounding duration were recorded. The presence or absence of a PA during each rounding encounter, the occurrence of an interruption, and other potential predictors of interruptions were recorded. The presence of a PA during PICU rounds was significantly associated (P < .001) with a 35.4% lower likelihood of an interruption. Family-centered rounds in the PICU are less likely to be interrupted when a PA is present. PAs help physicians and improve rounding efficiency by safely and effectively handling certain interruptions.

Synthesis of metal complexes involving Schiff base ligand with methylenedioxy moiety: spectral, thermal, XRD and antimicrobial studies.

PubMed

Sundararajan, M L; Jeyakumar, T; Anandakumaran, J; Karpanai Selvan, B

2014-10-15

Metal complexes of Zn(II), Cd(II), Ni(II), Cu(II), Fe(III), Co(II), Mn(II) Hg(II), and Ag(I) have been synthesized from Schiff base ligand, prepared by the condensation of 3,4-(methylenedioxy)aniline and 5-bromo salicylaldehyde. All the compounds have been characterized by using elemental analysis, molar conductance, FT-IR, UV-Vis, (1)H NMR, (13)C NMR, mass spectra, powder XRD and thermal analysis (TG/DTA) technique. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectral data suggest that the ligand coordinate to the metal atom by imino nitrogen and phenolic oxygen as bidentate manner. Mass spectral data further support the molecular mass of the compounds and their structure. Powder XRD indicates the crystalline state and morphology of the ligand and its metal complexes. The thermal behaviors of the complexes prove the presence of lattice as well as coordinated water molecules in the complexes. Melting point supports the thermal stability of all the compounds. The in vitro antimicrobial effects of the synthesized compounds were tested against five bacterial and three fungal species by well diffusion method. Antioxidant activities have also been performed for all the compounds. Metal complexes show more biological activity than the Schiff base. Copyright © 2014 Elsevier B.V. All rights reserved.

Effective Treatment of Manganese-Induced Occupational Parkinsonism With p-Aminosalicylic Acid: A Case of 17-Year Follow-Up Study

PubMed Central

Jiang, Yue-Ming; Mo, Xue-An; Du, Feng-Qi; Fu, Xue; Zhu, Xia-Yan; Gao, Hong-Yu; Xie, Jin-Lan; Liao, Feng-Ling; Pira, Enrico; Zheng, Wei

2014-01-01

Objective Chronic manganese (Mn) intoxication induces syndromes resembling Parkinson disease. The clinical intervention has largely been unsuccessful. We report a 17-year follow-up study of effective treatment of occupational Mn parkinsonism with sodium para-aminosalicylic acid (PAS). Methods The patient, female and aged 50 at the time of treatment, was exposed to airborne Mn for 21 years (1963–1984). The patient had palpitations, hand tremor, lower limb myalgia, hypermyotonia, and a distinct festinating gait. She received 6 g PAS per day through an intravenous drip infusion for 4 days and rested for 3 days as one therapeutic course. Fifteen such courses were carried out between March and June 1987. Results At the end of PAS treatment, her symptoms were significantly alleviated, and handwriting recovered to normal. Recent follow-up examination at age 67 years (in 2004) showed a general normal presentation in clinical, neurologic, brain magnetic resonance imaging, and handwriting examinations with a minor yet passable gait. Conclusions This case study suggests that PAS appears to be an effective drug for treatment of severe chronic Mn poisoning with a promising prognosis. PMID:16766929

Syntheses, characterisation and crystal structures of ferrocenyl β-diketones and their Schiff base Nsbnd Nsbnd O ligand derivatives with 2-picolylamine

NASA Astrophysics Data System (ADS)

Artigas, Vania; González, Deborah; Fuentealba, Mauricio

2017-02-01

Ferrocenyl β-diketones compounds β3-4 were synthesised by Claisen condensation reaction between acetylferrocene and ethyl benzoate or 4-bromoethyl benzoate. We also synthesised four new Schiff base ligands L1-4 by condensation reaction between β1-4 and 2-picolylamine. Identities of all these compounds were confirmed by satisfactory elemental analysis, 1H nuclear magnetic resonance (NMR) correlation and infrared (IR) spectroscopy. In addition, all these compounds were authenticated by a single-crystal X-ray diffraction analysis. In solution, 1H NMR spectra of β3 and β4 exhibit a mixture of keto:enol tautomer ratios of 12:88 and 8:92, respectively, calculated by the integration of the free cyclopentadienyl ring. In contrast, the proton NMR spectra of L1-4 showed only the keto-enamine tautomer displacements. In addition, decoupled 13C NMR spectrum clearly confirmed the existence of these tautomers. These results are in accordance with X-ray crystallographic studies, in which the enol and keto-enamine forms were elucidated for β-diketones and Schiff base ligands, respectively.

Design, spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases.

PubMed

Hanif, Muhammad; Chohan, Zahid H

2013-03-01

A new series of three biologically active triazole derived Schiff base ligands L(1)-L(3) have been synthesized in equimolar reaction of 3-amino-1H-1,2,4-triazole with pyrrol-2-carboxaldehyde, 4-bromo-thiophene-2-carboxaldehyde, and 5-iodo-2-hydroxy benzaldehyde. The prepared Schiff bases were used for further complex formation reaction with different metal elements like Co(II), Ni(II), Cu(II) and Zn(II) as chlorides by using a molar ratio of ligand:metal as 2:1. The structure and bonding nature of all the compounds were identified by their physical, spectral and analytical data. All the metal(II) complexes possessed an octahedral geometry except the Cu(II) complexes which showed a distorted octahedral geometry. All the synthesized compounds, were studied for their in vitro antibacterial, and antifungal activities, against four Gram-negative (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and against six fungal strains (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata) by using agar-well diffusion method. It has been shown that all the synthesized compounds showed moderate to significant antibacterial activity against one or more bacterial strains. In vitro Brine Shrimp bioassay was also carried out to investigate the cytotoxic properties of these compounds. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination. Copyright © 2012 Elsevier B.V. All rights reserved.

Ligational behavior of Schiff bases towards transition metal ion and metalation effect on their antibacterial activity

NASA Astrophysics Data System (ADS)

Devi, Jai; Batra, Nisha; Malhotra, Rajesh

2012-11-01

New Schiff bases pyrazine-2-carboxylicacid (phenyl-pyridin-2-yl-methylene)-hydrazide (Hpch-bp) HL1 and pyrazine-2-carboxylicacid (pyridin-2-ylmethylene)-hydrazide (Hpch-pc) HL2 derived from condensation of pyrazine carboxylic hydrazide (Hpch) with 2-benzoyl pyridine (bp) or pyridine 2-carbaldehyde (pc) and their transition metal complexes of type ML(1-2)2 have been synthesized, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). Characterization of ligands and their metal complexes was carried out by elemental analysis, conductimetric studies, magnetic susceptibility, spectroscopic techniques (IR, UV-VIS, NMR, ESR, Mass) and thermogravimetric analysis. The physico-chemical studies revealed octahedral geometry or distorted octahedral geometry around metal ion. These azomethine Schiff base ligands acted as tridentate ? coordinating through carbonyl, azomethine and pyridine nitrogen present in the ligand. The thermodynamic and thermal properties of the complexes have been investigated and it was observed on the basis of these studies that thermal stability of complexes follows the order Mn < Zn < Cu < Co < Ni. The ligands and their complexes were tested for in vitro antibacterial activity at different concentrations against bacteria viz. Gram positive Bacillus subtilis, Micrococcus luteus and Gram negative Pseudomonas aeruginosa, Pseudomonas mendocina. A marked enhancement in biocidal activity of the ligands under similar experimental conditions was observed as a consequence of coordination with metal ions. The trend of growth inhibition in the complexes was found to be in the order: Cu > Mn > Ni > Co > Zn.

Modification in band gap of zirconium complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Mayank, E-mail: mayank30134@gmail.com; Singh, J.; Chouhan, S.

2016-05-06

The optical properties of zirconium complexes with amino acid based Schiff bases are reported here. The zirconium complexes show interesting stereo chemical features, which are applicable in organometallic and organic synthesis as well as in catalysis. The band gaps of both Schiff bases and zirconium complexes were obtained by UV-Visible spectroscopy. It was found that the band gap of zirconium complexes has been modified after adding zirconium compound to the Schiff bases.

Comparison of phenolic acid profiles and anti-inflammatory effects of two major species of blueberries in the US

USDA-ARS?s Scientific Manuscript database

Blueberries (BB) contain high levels of polyphenols. Among them, phenolic acids (PAs) have been recently suggested as a group of important bioactive compounds. Highbush BB (Vaccinium corymbosum) and lowbush “wild" BB (Vaccinium angustifolium) are two predominant species in North America. The first o...

Studies on DNA binding behaviour of biologically active transition metal complexes of new tetradentate N2O2 donor Schiff bases: inhibitory activity against bacteria.

PubMed

Sobha, S; Mahalakshmi, R; Raman, N

2012-06-15

A series of Cu(II), Ni(II) and Zn(II) complexes of the type ML have been synthesized with Schiff bases derived from o-acetoacetotoluidide, 2-hydroxybenzaldehyde and o-phenylenediamine/1,4-diaminobutane. The complexes are insoluble in common organic solvents but soluble in DMF and DMSO. The measured molar conductance values in DMSO indicate that the complexes are non-electrolytic in nature. All the six metal complexes have been fully characterized with the help of elemental analyses, molecular weights, molar conductance values, magnetic moments and spectroscopic data. The analytical data helped to elucidate the structure of the metal complexes. The Schiff bases are found to act as tetradentate ligands using N(2)O(2) donor set of atoms leading to a square-planar geometry for the complexes around all the metal ions. The binding properties of metal complexes with DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. Detailed analysis reveals that the metal complexes intercalate into the DNA base stack as intercalators. All the metal complexes cleave the pUC19 DNA in presence of H(2)O(2.) The Schiff bases and their complexes have been screened for their antibacterial activity against five bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, Klebsiella pneumoniae) by disk diffusion method. All the metal complexes have potent biocidal activity than the free ligands. Copyright © 2012 Elsevier B.V. All rights reserved.

Schiff bases attached L-glutamine and L-asparagine: first investigation on antimutagenic and antimicrobial analyses.

PubMed

Sakiyan, Iffet; Anar, Mustafa; Oğütcü, Hatice; Agar, Guleray; Sarı, Nurşen

2014-06-01

This study was conducted to evaluate the antimutagenic and antimicrobial activities of Schiff bases attached L-glutamine and L-asparagine. Antibacterial activities of the compounds against S. aureus, Sh. dys. typ 7, L. monocytogenes 4b, E. coli, S. typhi H, S. epidermis, Br. abortus, M. luteus, B. cereus, P. putida, and antifungal activity against Candida albicans were studied. These compounds were investigated for antimutagenic properties against Aflatoxin Bı (AFBı) using micronuclei (MN) assay in human lymphocyte cell culture in vitro. The protective role of these compounds against AFBı-induced MN is probably related to its doses.

The Psychiatric Assessment Schedule for Adult with Developmental Disability (PAS-ADD) Checklist: Reliability and Validity of French Version

ERIC Educational Resources Information Center

Gerber, F.; Carminati, G. Galli

2013-01-01

Background: The lack of psychometric measures of psychopathology especially in intellectual disabilities (ID) population was addressed by creation of the Psychiatric Assessment Schedule for Adult with Developmental Disability (PAS-ADD-10) in Moss et?al. This schedule is a structured interview designed for professionals in psychopathology. The…

Effect of medium acidity on the thermodynamics and kinetics of the reaction of pyridoxal 5'-phosphate with isoniazid in an aqueous solution

NASA Astrophysics Data System (ADS)

Gamov, G. A.; Zavalishin, M. N.; Usacheva, T. R.; Sharnin, V. A.

2017-05-01

Thermodynamic characteristics of the formation of the Schiff base between isoniazid and pyridoxal 5'-phosphate in an aqueous solution at different pH values of a medium are determined by means of spectrophotometry and calorimetric titration. The process kinetics is studied spectrophotometrically, and the reaction rate constants for the formation of the imine at different acidities of a medium are determined. Biochemical aspects of the binding of pyridoxal 5'-phosphate into stable compounds are discussed.

Factors affecting the conversion of apple polyphenols to phenolic acids and fruit matrix to short-chain fatty acids by human faecal microbiota in vitro.

PubMed

Bazzocco, Sarah; Mattila, Ismo; Guyot, Sylvain; Renard, Catherine M G C; Aura, Anna-Marja

2008-12-01

Proanthocyanidins (PAs) in apples are condensed tannins comprised mostly of (-)-epicatechin units with some terminal (+)-catechins. PAs, especially those having a long chain-length, are absorbed in the upper intestine only to a small extent and are passed to the colon. In the colon they are subjected to microbial metabolism by colonic microbiota. In the present article, the ability of human microbiota to ferment apple PAs is studied. Freeze-dried fruit preparations (apple, enzymatically digested apple, isolated cell-walls, isolated PAs or ciders) from two varieties, Marie Ménard and Avrolles, containing PAs of different chain lengths, were compared. Fermentation studies were performed in an in vitro colon model using human faecal microbiota as an inoculum. The maximal extent of conversion to known microbial metabolites, was observed at late time point for Marie Ménard cider, having short PAs. In this case, the initial dose also contributed to the extent of conversion. Long-chain PAs were able to inhibit the in vitro microbial metabolism of PAs shown as low maxima at early time points. Presence of isolated PAs also suppressed SCFA formation from carbohydrates as compared with that from apple cell wall or faecal suspension without substrates. The low maximal extents at early time points suggest that there is a competition between the inhibitory effect of the PAs on microbial activity, and the ability to convert PAs by the microbiota.

Signal transduction and phosphoryl transfer by a FixL hybrid kinase with low oxygen affinity: importance of the vicinal PAS domain and receiver aspartate.

PubMed

Sousa, Eduardo H S; Tuckerman, Jason R; Gondim, Ana C S; Gonzalez, Gonzalo; Gilles-Gonzalez, Marie-Alda

2013-01-22

FixL is a prototype for heme-based sensors, multidomain proteins that typically couple a histidine protein kinase activity to a heme-binding domain for sensing of diatomic gases such as oxygen, carbon monoxide, and nitric oxide. Despite the relatively well-developed understanding of FixL, the importance of some of its domains has been unclear. To explore the impact of domain-domain interactions on oxygen sensing and signal transduction, we characterized and investigated Rhizobium etli hybrid sensor ReFixL. In ReFixL, the core heme-containing PAS domain and kinase region is preceded by an N-terminal PAS domain of unknown function and followed by a C-terminal receiver domain. The latter resembles a target substrate domain that usually occurs independently of the kinase and contains a phosphorylatable aspartate residue. We isolated the full-length ReFixL as a soluble holoprotein with a single heme b cofactor. Despite a low affinity for oxygen (K(d) for O₂ of 738 μM), the kinase activity was completely switched off by O₂ at concentrations well below the K(d). A deletion of the first PAS domain strongly increased the oxygen affinity but essentially prohibited autophosphorylation, although the truncated protein was competent to accept phosphoryl groups in trans. These studies provide new insights into histidyl-aspartyl phosphoryl transfers in two-component systems and suggest that the control of ligand affinity and signal transduction by PAS domains can be direct or indirect.

Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties.

PubMed

Yehye, Wageeh A; Abdul Rahman, Noorsaadah; Saad, Omar; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A; Kadir, Farkaad A; Yaeghoobi, Marzieh; Matlob, Abdulsalam A

2016-06-28

A new series of multipotent antioxidants (MPAOs), namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT) were designed and subsequently synthesized. The structure-activity relationship (SAR) of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS). The antioxidant activities of the synthesized compounds 4-10 were tested by the DPPH bioassay. The synthesized compounds 4-10 inhibited stable DPPH free radicals at a level that is 10(-4) M more than the well-known standard antioxidant BHT. Compounds 8-10 with para-substituents were less active than compounds 4 and 5 with trimethoxy substituents compared to those with a second BHT moiety (compounds 6 and 7). With an IC50 of 46.13 ± 0.31 µM, compound 6 exhibited the most promising in vitro inhibition at 89%. Therefore, novel MPAOs containing active triazole rings, thioethers, Schiff bases, and BHT moieties are suggested as potential antioxidants for inhibiting oxidative stress processes and scavenging free radicals, hence, this combination of functions is anticipated to play a vital role in repairing cellular damage, preventing various human diseases and in medical therapeutic applications.

Brain damage in a large cohort of solvent abusers.

PubMed

Al-Hajri, Zahra; Del Bigio, Marc R

2010-04-01

The neuropathology of solvent inhalation consists of patchy myelin loss with white matter macrophages that contain granular inclusions. It has been described only in a small number of cases. We sought to characterize the abnormalities in greater detail. In a retrospective study from 1995 to 2009, we encountered 88 autopsy cases with documented history of solvent abuse by inhalation and 1 with industrial exposure. Among these are 6 fetuses and infants with maternal exposure, 23 children (12-17 years), and 60 adults (18-66 years). Available brain samples from 75 cases were stained with solochrome cyanein (to demonstrate myelin) and periodic acid-Schiff (PAS) (to highlight the inclusions). Forty brains of ethanol and/or illicit drug exposed individuals and ten cases of multiple sclerosis were examined as controls. We found that 16 cases (age 23-49, median 37 years) had well-established leukoencephalopathy with multifocal myelin loss and abundant macrophages that stain with PAS and which contain birefringent inclusions. Six cases (age 15-55, median 27 years) had early leukoencephalopathy with scattered macrophages but no obvious myelin changes. Clusters of PAS-staining but non-birefringent macrophages were seen in 2/10 cases of (active) multiple sclerosis and in none of the ethanol/drug exposed brains. Ultrastructurally, inclusions from solvent cases differed from multiple sclerosis cases. Although exposure to solvents is impossible to quantify, there appears to be a duration-dependent effect. Brain damage related to solvent abuse can begin within only a few years of the onset. In the context of substance abuse, the changes are relatively specific for solvent inhalation and do not appear to result from demyelination alone. Interaction with ethanol cannot be excluded as a compounding risk factor.

Structural investigation, spectroscopic and energy level studies of Schiff base: 2-[(3‧-N-salicylidenephenyl)benzimidazole] using experimental and DFT methods

NASA Astrophysics Data System (ADS)

Suman, G. R.; Bubbly, S. G.; Gudennavar, S. B.; Muthu, S.; Roopashree, B.; Gayatri, V.; Nanje Gowda, N. M.

2017-07-01

The Schiff base 2-[(3‧-N-salicylidenephenyl)benzimidazole] (Spbzl) was characterized by FT-Raman, 1H NMR, 13C NMR and single crystal X-ray diffraction technique. Crystallographic studies reveal the presence of two water molecules in the asymmetry unit which aid the intermolecular hydrogen bonding with imidazole ring, and the trans-conformation of the azomethine bond. Theoretical computations conducted using density functional theory (DFT) analysis support the experimental facts. Energy levels estimated by DFT studies are in good agreement with the values obtained from cyclic voltammetry technique. Frontier molecular orbital analysis shows that charge transfer has taken place from donor to acceptor moiety, which is also supported by the high hyperpolarizability values in both gaseous and solution phases, indicating high charge transfer capability of the molecule. A comparative theoretical study of Spbzl with derivative 4-((3-(1H-benzimidazol-2-yl)phenylimino)methyl)-3-hydroxybenzoic acid (Pbzlb) having an added anchor group COOH substituted at para position in the acceptor ring has been made. The result shows the feasibility of charge transfer to the semiconductor surface in dye sensitized solar cell (DSSC) applications for Pbzlb.

Candida and calcofluor white: Study in precancer and cancer

PubMed Central

Kumar, Rashmi Santosh; Ganvir, SM; Hazarey, VK

2009-01-01

Background: The interest in oral candidosis has waxed and waned from the period of Hippocrates. The acquired immune deficiency syndrome (AIDS) epidemic has certainly bolstered these figures on oral candidosis, with diabetes and oral cancer being no exception. A need for rapid detection of Candida is made possible by the use of Calcofluor - White (CFW) stain when examined under a fluorescence microscope. The present study was aimed at assessing the efficacy of CFW is compared to Gram stain and periodic acid Schiff (PAS) in detection of Candida in oral precancer and cancer. Materials and Methods: The study group consisted of patients with precancer (n=45), cancer (n=45), and control group (n=45). Presence of Candida was confirmed by culture inoculation along with a germ tube and carbohydrate fermentation test. The cytopathological smears were analyzed by papanicolaou - CFW and Gram staining, whereas, tissue sections were stained by PAS and CFW staining. Results: Candida albicans was the predominant species identified. A highly significant association of Candida was seen more often in cancer than in precancer. Both in cytology and histopathology Candida detection by CFW was higher. In precancer it was 48.88% in smears and 40% in tissue sections, whereas, in cancer 60% in smears and 55.55% in histopathology. Conclusion: Among the various diagnostic tools used in the present study, the use of CFW is seen to be a simple, effective, rapid, and reliable method, both in cytopathology and histopathology. PMID:21886989

Inflammatory airway responses by nasal inoculation of suspended particulate matter in NC/Nga mice.

PubMed

Ogino, Keiki; Takahashi, Noriko; Kubo, Masayuki; Takeuchi, Akihito; Nakagiri, Motoharu; Fujikura, Yoshihisa

2014-06-01

To evaluate the allergic effect of airborne particulate matter (PM) on the airway, separated soluble supernatant (Sup) and insoluble precipitate (Pre) in suspended PM were inoculated into NC/Nga mice with a high sensitivity for mite allergens. Sup, Pre, or both Sup and Pre with or without pronase treatment were inoculated via the nasal route five times for sensitization and a challenge inoculation on the 11th day in NC/Nga mice. On the 14th day, mice were examined for airway hyperresponsiveness (AHR), bronchoalveolar lavage fluid (BALF) cell count, mRNA expression of Th1 and Th2 cytokines in the lung tissue, and histopathology. Synergistic effects of Sup and Pre were observed as increases in AHR and a histopathological change of Periodic acid-Schiff (PAS) staining. Increases in neutrophils, macrophages, and lymphocytes of BALF cells were dependent on Pre. The expression of IL-4 mRNA was increased by Sup, and those of IL-5 mRNA and Il-13 mRNA was increased by Sup and Pre. Augmented AHR, mRNA expression of IL-4, peribronchial inflammation, and PAS staining by Sup plus Pre were attenuated by treatment of Sup with pronase to digest proteins. These results suggest that some proteins of ambient PM may be important environmental factors for AHR and airway inflammation with the aid of insoluble particulates, although some soluble factors such as endotoxins cannot be ruled out. Copyright © 2012 Wiley Periodicals, Inc.

CADASIL accelerated by acute hypotension: Arterial and venous contribution to leukoaraiosis.

PubMed

Pettersen, Jacqueline A; Keith, Julia; Gao, Fuqiang; Spence, J David; Black, Sandra E

2017-03-14

To underline the importance of blood pressure regulation in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and to describe changes that occur in the veins in this condition, specifically venous collagenosis associated with leukoaraiosis. Case report with neuroimaging and pathologic data. A 61-year-old man with genetically confirmed CADASIL was initially lucid following a motor vehicle accident but subsequently became hypotensive (60/40 mm Hg) due to an open femur fracture and required intubation. Multiple new white matter infarcts appeared on brain imaging. A second hypotensive episode days later was associated with new coin-sized infarcts in the bilateral corona radiata and cerebellar peduncles, and resulted in quadriplegia. No embolic source was found on cardiac or vascular imaging. He died 5 weeks post trauma. Autopsy revealed extensive subcortical and periventricular leukoencephalopathy and multiple cavitations involving deep subcortical gray and white matter. Small arteries had thickened walls, disruption of the muscularis, and intimal periodic acid-Schiff (PAS)-positive material. Both larger periventricular and small caliber veins had thickened walls that were PAS-negative and trichrome-positive, consistent with venous collagenosis. There was no pathologic evidence of global hypoxia or diffuse axonal injury. The findings suggest rapid acceleration of CADASIL pathology from acute hypotension in the setting of impaired vasoreactivity. In addition, collagenosis of veins in the affected white matter regions suggests that the veins may play an important, though largely overlooked, role in maintaining white matter integrity. © 2017 American Academy of Neurology.

Menthone aryl acid hydrazones: a new class of anticonvulsants.

PubMed

Jain, Jainendra; Kumar, Y; Sinha, Reema; Kumar, Rajeev; Stables, James

2011-01-01

A series of ten compounds (Compounds J(1)-J(10)) of (±) 3-menthone aryl acid hydrazone was synthesized and characterized by thin layer chromatography and spectral analysis. Synthesized compounds were evaluated for anticonvulsant activity after intraperitoneal (i.p) administration to mice by maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure method and minimal clonic seizure test. Minimal motor impairment was also determined for these compounds. Results obtained showed that four compounds out of ten afforded significant protection in the minimal clonic seizure screen at 6 Hz. Compound J(6), 4-Chloro-N-(2-isopropyl-5-methylcyclohexylidene) benzohydrazide was found to be the most active compound with MES ED(50) of 16.1 mg/kg and protective index (pI) of greater than 20, indicating that (±) 3-menthone aryl acid hydrazone possesses better and safer anticonvulsant properties than other reported menthone derivatives viz. menthone Schiff bases, menthone semicarbazides and thiosemicarbazides.

Synthesis and Characterization of Chlorpyrifos/Copper(II) Schiff Base Mesoporous Silica with pH Sensitivity for Pesticide Sustained Release.

PubMed

Chen, Huayao; Lin, Yueshun; Zhou, Hongjun; Zhou, Xinhua; Gong, Sheng; Xu, Hua

2016-11-02

The salicylaldehyde-modified mesoporous silica (SA-MCM-41) was prepared through a co-condensation method. Through the bridge effect from the copper ion, which also acts as the nutrition of the plant, the model drug chlorpyrifos (CH) was supported on the copper(II) Schiff base mesoporous silica (Cu-MCM-41) to form a highly efficient sustained-release system (CH-Cu-MCM-41) for pesticide delivery. The experimental results showed that the larger the concentration of the copper ion, the more adsorption capacity (AC) of Cu-MCM-41 for chlorpyrifos and the smaller its release rate. The results confirmed the existence of a coordination bond between SA-MCM-41 and copper ions as well as a coordination bond between Cu-MCM-41 and chlorpyrifos. The AC of SA-MCM-41 is 106 mg/g, while that of Cu-MCM-41 is 295 mg/g. The as-synthesized system showed significant pH sensitivity. Under the condition of pH ≤ 7, the release rate of chlorpyrifos decreased with increasing pH, whereas its release rate in weak base conditions was slightly larger than that in weak acid conditions. Meanwhile, the drug release rate of the as-synthesized system was also affected by the temperature. Their sustained-release curves can be described by the Korsmeyer-Peppas equation.

How vertebrate and invertebrate visual pigments differ in their mechanism of photoactivation

PubMed Central

Nakagawa, Masashi; Iwasa, Tatsuo; Kikkawa, Satoshi; Tsuda, Motoyuki; Ebrey, Thomas G.

1999-01-01

In vertebrate visual pigments, a glutamic acid serves as a negative counterion to the positively charged chromophore, a protonated Schiff base of retinal. When photoisomerization leads to the Schiff base deprotonating, the anionic glutamic acid becomes protonated, forming a neutral species that activates the visual cascade. We show that in octopus rhodopsin, the glutamic acid has no anionic counterpart. Thus, the “counterion” is already neutral, so no protonated form of an initially anionic group needs to be created to activate. This helps to explain another observation—that the active photoproduct of octopus rhodopsin can be formed without its Schiff base deprotonating. In this sense, the mechanism of light activation of octopus rhodopsin is simpler than for vertebrates, because it eliminates one of the steps required for vertebrate rhodopsins to achieve their activating state. PMID:10339563

Safety evaluation for packaging for the transport of K Basin sludge samples in the PAS-1 cask

DOE Office of Scientific and Technical Information (OSTI.GOV)

SMITH, R.J.

1998-11-17

This safety evaluation for packaging authorizes the shipment of up to two 4-L sludge samples to and from the 325 Lab or 222-S Lab for characterization. The safety of this shipment is based on the current U.S. Department of Energy Certification of Compliance (CoC) for the PAS-1 cask, USA/9184/B(U) (DOE).

Anaortic off-pump versus clampless off-pump using the PAS-Port device versus conventional coronary artery bypass grafting: mid-term results from a matched propensity score analysis of 5422 unselected patients.

PubMed

Furukawa, Nobuyuki; Kuss, Oliver; Preindl, Konstantin; Renner, André; Aboud, Anas; Hakim-Meibodi, Kavous; Benzinger, Michael; Pühler, Thomas; Ensminger, Stephan; Fujita, Buntaro; Becker, Tobias; Gummert, Jan F; Börgermann, Jochen

2017-10-01

Meta-analyses from observational and randomized studies have demonstrated benefits of off-pump surgery for hard and surrogate endpoints. In some of them, increased re-revascularization was noted in the off-pump groups, which could impact their long-term survival. Therefore, we analyzed the course of all patients undergoing isolated coronary surgery regarding the major cardiac and cerebrovascular event (MACCE) criteria. A prospective register was taken from a high-volume off-pump center recording all anaortic off-pump (ANA), clampless off-pump (PAS-Port) and conventional (CONV) coronary artery bypass operations between July 2009 and June 2015. Propensity Score Matching was performed based on 28 preoperative risk variables. We identified 935 triplets (N = 2805). Compared with CONV, in-hospital mortality of both the ANA group (OR for ANA [95% CI] 0.25 [0.06; 0.83], P = 0.021), and the PAS-Port group was lower (OR for PAS-Port [95% CI] 0.50 [0.17; 1.32], P = 0.17). In the mid-term follow-up there were no significant differences between the groups regarding mortality (HR for ANA [95%-CI] 0.83 [0.55-1.26], P = 0.38; HR for PAS-Port [95%-CI] 1.06 [0.70-1.59], P = 0.79), incidence of stroke (HR for ANA 0.81 [0.43-1.53], P = 0.52; HR for PAS-Port 0.78 [0.41-1.50], P = 0.46), myocardial infarction (HR for ANA 0.53 [0.22-1.31], P = 0.17; HR for PAS-Port 0.78 [0.37-1.66], P = 0.52) or re-revascularization rate (HR for ANA 0.99 [0.67-1.44], P = 0.94; HR for PAS-Port 0.95 [0.65-1.38], P = 0.77). Both off-pump clampless techniques were associated with lower in-hospital mortality compared with conventional CABG. The mid-term course showed no difference with regard to the MACCE criteria between anaortic off-pump, clampless off-pump using PAS-Port and conventional CABG. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

New fluorescent azo-Schiff base Cu(II) and Zn(II) metal chelates; spectral, structural, electrochemical, photoluminescence and computational studies

NASA Astrophysics Data System (ADS)

Purtas, Fatih; Sayin, Koray; Ceyhan, Gokhan; Kose, Muhammet; Kurtoglu, Mukerrem

2017-06-01

A new Schiff base containing azo chromophore group obtained by condensation of 2-hydroxy-4-[(E)-phenyldiazenyl]benzaldehyde with 3,4-dimethylaniline (HL) are used for the syntheses of new copper(II) and zinc(II) chelates, [Cu(L)2], and [Zn(L)2], and characterized by physico-chemical and spectroscopic methods such as 1H and 13C NMR, IR, UV.-Vis. and elemental analyses. The solid state structure of the ligand was characterized by single crystal X-ray diffraction study. X-ray diffraction data was then used to calculate the harmonic oscillator model of aromaticity (HOMA) indexes for the rings so as to investigate of enol-imine and keto-amine tautomeric forms in the solid state. The phenol ring C10-C15 shows a considerable deviation from the aromaticity with HOMA value of 0.837 suggesting the shift towards the keto-amine tautomeric form in the solid state. The analytical data show that the metal to ligand ratio in the chelates was found to be 1:2. Theoretical calculations of the possible isomers of the ligand and two metal complexes are performed by using B3LYP method. Electrochemical and photoluminescence properties of the synthesized azo-Schiff bases were also investigated.

A Forecast Skill Comparison between CliPAS One-Tier and Two-Tier Hindcast Experiments

NASA Astrophysics Data System (ADS)

Lee, J.; Wang, B.; Kang, I.

2006-05-01

A 24-year (1981-2004) MME hindcast experimental dataset is produced under the "Climate Prediction and Its Application to Society" (CliPAS) project sponsored by Korean Meteorological Administration (KMA). This dataset consists of 5 one-tier model systems from National Aeronautics and Space Administration (NASA), National Center for Environmental Prediction (NCEP), Frontier Research Center for Global Change (FRCGC), Seoul National University (SNU), and University of Hawaii (UH) and 5 two-tier model systems from Florida State University (FSU), Geophysical Fluid Dynamic Lab (GFDL), SNU, and UH. Multi-model Ensemble (MME) Forecast skills of seasonal precipitation and atmospheric circulation are compared between CliPAS one-tier and two-tier hindcast experiments for seasonal mean precipitation and atmospheric circulation. For winter prediction, two-tier MME has a comparable skill to one-tier MME. However, it is demonstrated that in the Asian-Australian monsoon (A-AM) heavy precipitation regions, one-tier systems are superior to two-tier systems in summer season. The reason is that inclusion of the local warm pool- monsoon interaction in the one-tier system improves the ENSO teleconnection with monsoon regions. Both one-tier and two-tier MME fail to predict Indian monsoon circulation, while they have a significantly good skill for the broad scale monsoon circulation defined by Webster and Yang index. One-tier system has a much better skill to predict the monsoon circulation over the western North pacific where air-sea interaction plays an important role than two-tier system.

Exploration of cellular DNA lesion, DNA-binding and biocidal ordeal of novel curcumin based Knoevenagel Schiff base complexes incorporating tryptophan: Synthesis and structural validation

NASA Astrophysics Data System (ADS)

Chandrasekar, Thiravidamani; Raman, Natarajan

2016-07-01

A few novel Schiff base transition metal complexes of general formula [MLCl] (where, L = Schiff base, obtained by the condensation reaction of Knoevenagel condensate of curcumin, L-tryptophan and M = Cu(II), Ni(II), Co(II), and Zn(II)), were prepared by stencil synthesis. They were typified using UV-vis, IR, EPR spectral techniques, micro analytical techniques, magnetic susceptibility and molar conductivity. Geometry of the metal complexes was examined and recognized as square planar. DNA binding and viscosity studies revealed that the metal(II) complexes powerfully bound via an intercalation mechanism with the calf thymus DNA. Gel-electrophoresis technique was used to investigate the DNA cleavage competence of the complexes and they establish to approve the cleavage of pBR322 DNA in presence of oxidant H2O2. This outcome inferred that the synthesized complexes showed better nuclease activity. Moreover, the complexes were monitored for antimicrobial activities. The results exposed that the synthesized compounds were forceful against all the microbes under exploration.

Cinnamic acid-inhibited ribulose-1,5-bisphosphate carboxylase activity is mediated through decreased spermine and changes in the ratio of polyamines in cowpea.

PubMed

Huang, Xingxue; Bie, Zhilong

2010-01-01

This study investigated the effects of cinnamic acid (CA) on ribulose-1,5-bisphosphate carboxylase (RuBPC) activity and the endogenous polyamine levels of cowpea leaves. The results show that 0.1 mM CA treatment decreased photosynthetic rate (P(n)) and RuBPC activity, but it did not affect the maximal photochemical efficiency of PSII (F(v)/F(m)), the actual photochemical efficiency of PSII (PhiPSII), intercellular CO(2) concentration (C(i)), and relative chlorophyll content. These suggest that the decrease in P(n) is at least partially attributed to a lowered RuBPC activity. In addition, 0.1 mM CA treatment increased the putrescine (Put) level, but decreased spermidine (Spd) and spermine (Spm) levels, thereby reducing the (Spd+Spm)/Put (PAs) ratio in the leaves. The exogenous application of 1 mM Spd markedly reversed these CA-induced effects for polyamine and partially restored the PAs ratio and RuBPC activity in leaves. Methylglyoxal-bis (guanylhydrazone) (MGBG), which is an inhibitor of S-adenosylmethionine decarboxylase (SAMDC), results in the inability of activated cells to synthesize Spd and exacerbates the negative effects induced by CA. The exogenous application of 1 mM D-arginine (D-Arg), which is an inhibitor of Put biosynthesis, decreased the levels of Put, but increased the PAs ratio and RuBPC activity in leaves. These results suggest that 0.1 mM CA inhibits RuBPC activity by decreasing the levels of endogenous free and perchloric acid soluble (PS) conjugated Spm, as well as the PAs ratio.

Synthesis, characterization and antimicrobial studies of Schiff base complexes

NASA Astrophysics Data System (ADS)

Zafar, Hina; Ahmad, Anis; Khan, Asad U.; Khan, Tahir Ali

2015-10-01

The Schiff base complexes, MLCl2 [M = Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] have been synthesized by the template reaction of respective metal ions with 2-acetylpyrrole and 1,3-diaminopropane in 1:2:1 M ratio. The complexes have been characterized by elemental analyses, ESI - mass, NMR (1H and 13C), IR, XRD, electronic and EPR spectral studies, magnetic susceptibility and molar conductance measurements. These studies show that all the complexes have octahedral arrangement around the metal ions. The molar conductance measurements of all the complexes in DMSO indicate their non-electrolytic nature. The complexes were screened for their antibacterial activity in vitro against Gram-positive (Streptococcus pyogenes) and Gram-negative (Klebsiella pneumoniae) bacteria. Among the metal complexes studied the copper complex [CuLCl2], showed highest antibacterial activity nearly equal to standard drug ciprofloxacin. Other complexes also showed considerable antibacterial activity. The relative order of activity against S. Pyogenes is as Cu(II) > Zn(II) > Co(II) = Fe(II) > Ni(II) and with K. Pneumonia is as Cu(II) > Co(II) > Zn(II) > Fe(II) > Ni(II).

The influence of manganese treatment on the distribution of metal elements in rats and the protection by sodium para-amino salicylic acid.

PubMed

Yuan, Zong-Xiang; Chen, Hai-Bin; Li, Shao-Jun; Huang, Xiao-Wei; Mo, Yu-Huan; Luo, Yi-Ni; He, Sheng-Nan; Deng, Xiang-Fa; Lu, Guo-Dong; Jiang, Yue-Ming

2016-07-01

Manganese (Mn) overexposure induced neurological damages, which could be potentially protected by sodium para-aminosalicylic acid (PAS-Na). In this study, we systematically detected the changes of divalent metal elements in most of the organs and analyzed the distribution of the metals in Mn-exposed rats and the protection by PAS-Na. Sprague Dawley (SD) rats received intraperitoneal injections of 15mg/kg MnCl2·4H2O (5d/week for 3 weeks), followed by subcutaneous (back) injections of PAS-Na (100 and 200mg/kg, everyday for 5 weeks). The concentrations of Mn and other metal elements [Iron (Fe), Copper (Cu), Zinc (Zn), Magnesium (Mg), Calcium (Ca)] in major organs (liver, spleen, kidney, thighbone and iliac bone, cerebral cortex, hippocampus and testes) and blood by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The results showed that Mn overexposure significantly increased Mn in most organs, Fe and Zn in liver, Fe and Mg in blood; however decreased Fe, Cu, Zn, Mg and Ca in cortex, Cu and Zn in kidney, Cu and Mg in iliac bone, and Zn in blood. In contrast, PAS-Na treatment restored most changes particularly in cortex. In conclusion, excessive Mn exposure disturbed the balance of other metal elements but PAS-Na post-treatments could restore these alterations. Copyright © 2016 Elsevier GmbH. All rights reserved.

Purification and characterization of a novel high molecular weight exotoxin produced by red tide phytoplankton, Alexandrium tamarense.

PubMed

Yamasaki, Yasuhiro; Katsuo, Daisuke; Nakayasu, Seiichiro; Salati, Cristina; Duan, JingJing; Zou, Yanan; Matsuyama, Yukihiko; Yamaguchi, Kenichi; Oda, Tatsuya

2008-01-01

Our recent studies have demonstrated that the aqueous extract prepared from Alexandrium tamarense, a harmful red tide phytoplankton, showed cytotoxicity on Vero cells. In this study, the toxic substance was purified from the culture supernatant of A. tamarense. Based on the gel-filtration profile, the molecular mass of a purified toxin was estimated to be about 1,000 kDa. On sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, a main band with molecular mass of 1,000 kDa was detected with periodic acid-Schiff (PAS) staining, but no protein bands were detected by Coomassie brilliant blue (CBB) protein staining. Sugar composition analysis of the toxin suggested that the toxin contains galactose, fucose, mannose, N-acetylglucosamine, xylose, and other minor saccharides, whereas no significant levels of amino acids were detected by amino acid analysis. These results suggest that the toxin is a polysaccharide-based compound. The toxin showed cytotoxic effects on various cell lines in a concentration-dependent manner. Among the cell lines tested, U937 cells were the most susceptible to the toxin. In U937 cells treated with the toxin, a typical apoptotic nuclear morphological change and DNA fragmentation were observed. This is the first report demonstrating that a polysaccharide-based toxin isolated from red tide phytoplankton can induce apoptotic cell death. (c) 2008 Wiley Periodicals, Inc.

Histochemical and ultrastructural study of the chicken salivary palatine glands.

PubMed

Samar, María E; Avila, Rodolfo E; Esteban, Francisco J; Olmedo, Luis; Dettin, Luis; Massone, Adriana; Pedrosa, Juan A; Peinado, María A

2002-01-01

Salivary glands are a good model to investigate the relationship between cell secretion and glandular structure. Most studies of this organ deal with mammals, but we are interested in a morphofunctional characterization of these glands in poultry in relation with particular feeding habits. For this purpose, conventional and lectin histochemical methods as well as ultrastructural methods have been applied to the chicken lateral and medial palatine salivary glands. It was found that periodic acid-Schiff (PAS)-positive, alcianophilic, and metachromatic or orthochromatic cells were present with a more homogeneous distribution pattern in lateral glands than in medial palatine glands. Lectin staining depended on the lectin type that was applied, but also on the glandular part both in lateral and medial glands. Ultrastructural studies showed cytoplasmic membranous structures with a scattered granular or filamentous content depending on the secretory cell. In conclusion, morphofunctional characteristics of salivary glands of chicken suggest that their products are involved in lubrication and humidification of food ingested, and probably in protection of the oral surface, as has been previously described for other animals showing similar histochemical staining patterns.

Anti-inflammatory effects of tilmicosin in a noninfectious mouse model of allergic asthma.

PubMed

Ci, Xinxin; Chu, Xiao; Xiang, Hua; Li, Xiangchao; Deng, Xuming

2011-12-01

Tilmicosin, a semi-synthetic tylosin-derived macrolide antibiotic commonly used by veterinarians, has been shown to possess anti-inflammatory activity. However, possible use in asthma treatment has not yet been studied. In this study, we investigated the anti-inflammatory properties of tilmicosin using a murine asthma model. BALB/c mice were sensitized and challenged by intraperitoneal (i.p.) or nasal administration of ovalbumin. Tilmicosin (10 and 20 mg/kg) treatment resulted in a marked reduction in the presence of several types of immune cells and cytokines in the bronchoalveolar lavage fluids of mice. Levels of ovalbumin-specific Immunoglobulin E (IgE) were significantly decreased following treatment with tilmicosin (10 and 20 mg/kg). Histological studies using H&E (haematoxylin and eosin) and AB-PAS (alcian blue-periodic acid-Schiff) staining demonstrated that tilmicosin substantially inhibited both ovalbumin-induced inflammatory cells in lung tissues and goblet cell hyperplasia in the airway. These findings provided new insight into the immunopharmacological role of tilmicosin in terms of its effects in a murine model of asthma.

[Establishment and characterization of a cell line derived from human ovarian mucinous cystadenocarcinoma].

PubMed

Wan, Q; Xu, D; Li, Z

2001-07-01

To establish a cell line of human ovarian cancer, and study its characterization. The cell line was established by the cultivation of subsides walls, and kept by freezing. The morphology was observed by microscope and electromicroscope. The authors studied its growth and propagation, the agglutination test of phytohemagglutinin (PHA), the chromosome analysis, heterotransplanting, immuno-histochemistry staining, the analysis of hormone, the pollution examination and the test of sensitivity to virus etc. A new human ovarian carcinoma cell line, designated ovarian mucinous cystadenocarcinoma 685 (OMC685), was established from mucinous cystadenocarcinoma. This cell line had subcultured to 91 generations, and some had been frozen for 8 years and revived, still grew well. This cell line possessed the feature of glandular epithelium cancer cell. The cells grew exuberantly, and the agglutinating test of PHA was positive. Karyotype was subtriploid with distortion. Heterotransplantations, alcian blue periobic acid-schiff (AbPAS), mucicarmine, alcian blue stainings, estradiol (E2) and progesterone were all positive. Without being polluted, it was sensitive to polivirus-I, adenovirus 7 and measles virus. OMC685 is a distinct human ovarian tumous cell line.

Whitespotted puffer Arothron hispidus, a new host for lymphocystis in Qingdao Aquarium of China.

PubMed

Sheng, Xiu-zhen; Zhan, Wen-bin; Wang, Yue

2007-03-29

In April 2004 white nodular lesions were found on the fins of whitespotted puffer Arothron hispidus (Linnaeus). Diagnostic studies were carried out to confirm the disease using light and electron microscopy, histochemical methods and PCR. The results revealed that the nodules were composed of giant cells up to 400 microm in diameter. These cells were surrounded by a periodic acid-Schiff (PAS)-positive hyaline capsule containing dot-shaped, Feulgen-positive inclusion bodies in the cytoplasm and an irregular nucleus. Numerous virus particles 200 nm in diameter and with hexagonal profiles were observed in the cytoplasm. These features were consistent with those of lymphocystis disease. Additionally, based on the gene sequences of major capsid protein (MCP) of lymphocystis disease virus (LCDV) from Japanese flounder Paralichthys olivaceus, 2 pair primers were designed; after a nested PCR was performed for detection of LCDV in A. hispidus, a positive amplified product was obtained showing the presence of LCDV. Therefore, the white nodules were the lymphocystis lesions caused by LCDV infection and A. hispidus was demonstrated to be a new host for LCDV.

Investigation and kinetic evaluation of the reactions of hydroxymethylfurfural with amino and thiol groups of amino acids.

PubMed

Hamzalıoğlu, Aytül; Gökmen, Vural

2018-02-01

In this study, reactions of hydroxymethylfurfural (HMF) with selected amino acids (arginine, cysteine and lysine) were investigated in HMF-amino acid (high moisture) and Coffee-amino acid (low moisture) model systems at 5, 25 and 50°C. The results revealed that HMF reacted efficiently and effectively with amino acids in both high and low moisture model systems. High-resolution mass spectrometry (HRMS) analyses of the reaction mixtures confirmed the formations of Michael adduct and Schiff base of HMF with amino acids. Calculated pseudo-first order reaction rate constants were in the following order; k Cysteine >k Arginine >k Lysine for high moisture model systems. Comparing to these rate constants, the k Cysteine decreased whereas, k Arginine and k Lysine increased under the low moisture conditions of Coffee-amino acid model systems. The temperature dependence of the rate constants was found to obey the Arrhenius law in a temperature range of 5-50°C under both low and high moisture conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

The syntheses, molecular structure analyses and DFT studies on new benzil monohydrazone based Schiff bases

NASA Astrophysics Data System (ADS)

Elmacı, Gökhan; Duyar, Halil; Aydıner, Burcu; Seferoğlu, Nurgül; Naziri, Mir Abolfazl; Şahin, Ertan; Seferoğlu, Zeynel

2018-06-01

Benzil monohydrazone based Schiff bases were synthesized and characterized by 1H NMR, 13C NMR, HRMS as well as by single crystal X-ray diffraction. The geometries of the compounds was optimized by the DFT method and the results were compared with the X-ray diffraction data. The HOMO and LUMO energy gap and also related parameters (electronic chemical potential (μ) and global hardness (η), global electrophilicity index (ω) and softness (s)) were obtained from ground state calculations. In addition, the thermal properties of the compounds were investigated by DTA-TGA. The results showed that the compounds have good thermal properties for practical applications as optic dye.

Synthesis and characterization of copper complexes of Schiff base derived from isatin and salicylic hydrazide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lekshmy, R. K., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com; Thara, G. S., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com

A series of novel metal complexes of Schiff base have been prepared by the interaction of Cu(II) with isatin salicylic hydrazide. All the new compounds were characterized by elemental analysis, conductance measurement, magnetic moment determination, IR, UV, NMR, Mass and EPR spectral studies, thermal studies and microbial activities. The results indicate that the ligand acts as a tridentate chelating ligand coordinating through nitrogen and oxygen atoms. The ligand and complexes show inactive against Escherichia coli and active against Staphylococcus aureus and B.substilis. By analyzing the results of spectral, thermal and elemental analysis square planar geometry is proposed for all themore » complexes.« less

Spectral characterization, thermal and biological activity studies of Schiff base complexes derived from 4,4‧-Methylenedianiline, ethanol amine and benzil

NASA Astrophysics Data System (ADS)

Emam, Sanaa Moustafa

2017-04-01

Some new metal(II) complexes of asymmetric Schiff base ligand were prepared by template technique. The shaped complexes are in binuclear structures and were explained through elemental analysis, molar conductivity, various spectroscopic methods (IR, U.V-Vis, XRD, ESR), thermal (TG) and magnetic moment measurements. The IR spectra were done demonstrating that the Schiff base ligand acts as neutral tetradentate moiety in all metal complexes. The electronic absorption spectra represented octahedral geometry for all complexes, while, the ESR spectra for Cu(II) complex showed axially symmetric g-tensor parameter with g׀׀ > g⊥ > 2.0023 indicating to 2B1g ground state with (dx2-y2)1 configuration. The nature of the solid residue created from TG estimations was affirmed utilizing IR and XRD spectra. The biological activity of the prepared complexes was studied against Land Snails. Additionally, the in vitro antitumor activity of the synthesized complexes with Hepatocellular Carcinoma cell (Hep-G2) was examined. It was observed that Zn(II) complex (5), exhibits a high inhibition of growth of the cell line with IC50 of 7.09 μg/mL.

Synthesis, pH dependent photometric and electrochemical investigation, redox mechanism and biological applications of novel Schiff base and its metallic derivatives

NASA Astrophysics Data System (ADS)

Rauf, Abdur; Shah, Afzal; Khan, Abdul Aziz; Shah, Aamir Hassan; Abbasi, Rashda; Qureshi, Irfan Zia; Ali, Saqib

2017-04-01

A novel Schiff base, 1-((2, 4-dimethylphenylimino)methyl)naphthalen-2-ol abbreviated as (HL) and its four metallic complexes were synthesized and confirmed by 1H and 13C NMR, FTIR, TGA and UV-Visible spectroscopy. Schiff base was also characterized by X-ray analysis. The photometric and electrochemical responses of all the synthesized compounds were investigated in a wide pH range. Structures of the compounds were optimized computationally for the evaluation of different physico-chemical parameters. On the basis of electrochemical results the redox mechanistic pathways of the compounds were proposed. The cytotoxicity analysis on Hela cells revealed that HL and its complexes inhibit cell growth as revealed from their IC50 values (HL):106.7 μM, (L2VO): 40.66 μM, (L2Sn): 5.92 μM, (L2Zn): 42.82 and (L2Co): 107.68 μM. The compounds were tested for anti-diabetic, triglyceride, cholesterol, anti-microbial, anti-fungal and enzyme inhibition activities. The results revealed that HL and its complexes are promising new therapeutic options as these compounds exhibit strong activity against cancer cells, diabetics, fungal and microbial inhibition.

Syntheses, characterization, superoxide dismutase, antimicrobial, crystal structure and molecular studies of copper (II) and nickel (II) complexes with 2-((E)-(2, 4-dibromophenylimino) methyl)-4-bromophenol as Schiff base ligand

NASA Astrophysics Data System (ADS)

Bharti, Sulakshna; Choudhary, Mukesh; Mohan, Bharti; Rawat, S. P.; Sharma, S. R.; Ahmad, Khursheed

2017-12-01

Three new copper (II) and nickel (II) complexes viz. [Cu(L)2](1a), [Cu(L)2](1b) and [Ni(L)2].DMF(2), where HL = 2-((E)-(2, 4-dibromophenylimino) methyl)-4-bromophenol, have been synthesized and characterized by using various physico-chemical and spectroscopic techniques. The crystal structures of Schiff base (HL) and their metal complexes (1a), (1b) and (2) were determined by single crystal X-ray diffraction. IR and UV-Vis spectra and magnetic susceptibility measurements agree with the observed crystal structures. The crystallographic and spectroscopic studies confirmed four coordinate environments around the metal (II) ions. The synthesized Schiff base ligand (HL) crystallizes in the orthorhombic system of the space group Pbca. Complex (1a) of HL was crystallized in the monoclinic system of the space group P21/c, a = 10.1712(9) Å, b = 10.9299(10) Å,c = 12.7684(11) Å,α = 90̊,β = 104.649(2)̊, γ = 90̊ and Z = 2 whereas complex (1b) and (2) crystallized in the triclinic system of the space group P-1, a = 11.499(5)Å, b = 11.598(5)Å, c = 12.211(5)Å, α = 98.860(5), β = 115.653(5),γ = 100.906(5) and Z = 2 for (1b), a = 9.080(6) Å, b = 9.545(8)Å, c = 9.545(8)Å, α = 101.43(4)º,β = 99.63(3)̊, γ = 117.71(2)º and Z = 1 for (2). The synthesized ligand (HL) was behaved as monobasic bidentate Schiff base ligand having N and O donor sites. The electron paramagnetic resonance spectra indicate a dx2-y2ground state (g|| > g⊥> 2.0023) for (1a) and (1b). Copper (II) complexes display X-band EPR spectra in 100% DMSO and 77 K, giving indicating dx2-y2ground state. Superoxide dismutase-like activities of HL and its complexes were investigated by nitrobluetetrazolium chloride-DMSO assay and IC50 values were evaluated. These complexes were also tested for their in vitro antimicrobial activities against two bacteria (E. coli and Salmonella typhi) and two fungi (Pencillium, Aspergillus sp.) comparing with the Schiff base. The antimicrobial results showed that the

Synthesis, characterization and biological approach of metal chelates of some first row transition metal ions with halogenated bidentate coumarin Schiff bases containing N and O donor atoms.

PubMed

Prabhakara, Chetan T; Patil, Sangamesh A; Toragalmath, Shivakumar S; Kinnal, Shivashankar M; Badami, Prema S

2016-04-01

The impregnation of halogen atoms in a molecule is an emerging trend in pharmaceutical chemistry. The presence of halogens (Cl, Br, I and F) increases the lipophilic nature of molecule and improves the penetration of lipid membrane. The presence of electronegative halogen atoms increases the bio- activity of core moiety. In the present study, Co(II), Ni(II) and Cu(II) complexes are synthesised using Schiff bases (HL(I) and HL(II)), derived from 8-formyl-7-hydroxy-4-methylcoumarin/3-chloro-8-formyl-7-hydroxy-4-methylcoumarin with 2,4-difluoroaniline/o-toluidine respectively. The synthesized compounds were characterized by spectral (IR, NMR, UV-visible, Mass, ESI-MS, ESR), thermal, fluorescence and molar conductivity studies. All the synthesized metal complexes are completely soluble in DMF and DMSO. The non-electrolytic nature of the metal complexes was confirmed by molar conductance studies. Elemental analysis study suggest [ML2(H2O)2] stoichiometry, here M=Co(II), Ni(II) and Cu(II), L=deprotonated ligand. The obtained IR data supports the binding of metal ion to Schiff base. Thermal study suggests the presence of coordinated water molecules. Electronic spectral results reveal six coordinated geometry for the synthesized metal complexes. The Schiff bases and their metal complexes were evaluated for antibacterial (Pseudomonas aureginosa and Proteus mirabilis), antifungal (Aspergillus niger and Rhizopus oryzae), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activities. Copyright © 2016 Elsevier B.V. All rights reserved.

Spectroscopic and biological activities studies of bivalent transition metal complexes of Schiff bases derived from condensation of 1,4-phenylenediamine and benzopyrone derivatives.

PubMed

Sherif, Omaima E; Abdel-Kader, Nora S

2014-01-03

Many tools of analysis such as elemental analyses, infrared, ultraviolet-visible, electron spin resonance (ESR) and thermal analysis, as well as conductivity and magnetic susceptibility measurements were used to elucidate the structures of the newly prepared Co(II), Ni(II) and Cu(II) complexes with Schiff bases derived from the condensation of 1,4-phenylenediamine with 6-formyl-7-hydroxy-5-methoxy-2-methylbenzo-pyran-4-one (H2L) or 5,7-dihydroxy-6-formyl-2-methylbenzopyran-4-one (H4L). The data showed that all formed complexes are 1:1 or 2:2 (M:L) and non-electrolyte chelates. The Co(II) and Cu(II) complexes of the two Schiff bases were screened for antibacterial activities by the disk diffusion method. The antibacterial activity was screened using Escherichia coli and Staphylococcus capitis but the antifungal activity was examined by using Aspergillus flavus and Candida albicans. The Results showed that the tested complexes have antibacterial, except CuH4L, but not antifungal activities. Copyright © 2013 Elsevier B.V. All rights reserved.

Computational studies of molecular charge transfer complexes of heterocyclic 4-methylepyridine-2-azomethine-p-benzene derivatives with picric acid and m-dinitrobenzene.

PubMed

Al-Harbi, L M; El-Mossalamy, E H; Obaid, A Y; Al-Jedaani, A H

2014-01-01

Charge transfer complexes of substituted aryl Schiff bases as donors with picric acid and m-dinitrobenzene as acceptors were investigated by using computational analysis calculated by Configuration Interaction Singles Hartree-Fock (CIS-HF) at standard 6-31G∗ basis set and Time-Dependent Density-Functional Theory (TD-DFT) levels of theory at standard 6-31G∗∗ basis set, infrared spectra, visible and nuclear magnetic resonance spectra are investigated. The optimized geometries and vibrational frequencies were evaluated. The energy and oscillator strength were calculated by Configuration Interaction Singles Hartree-Fock method (CIS-HF) and the Time-Dependent Density-Functional Theory (TD-DFT) results. Electronic properties, such as HOMO and LUMO energies and band gaps of CTCs set, were studied by the Time-Dependent density functional theory with Becke-Lee-Young-Parr (B3LYP) composite exchange correlation functional and by Configuration Interaction Singles Hartree-Fock method (CIS-HF). The ionization potential Ip and electron affinity EA were calculated by PM3, HF and DFT methods. The columbic force was calculated theoretically by using (CIS-HF and TD-DFT) methods. This study confirms that the theoretical calculation of vibrational frequencies for (aryl Schiff bases--(m-dinitrobenzene and picric acid)) complexes are quite useful for the vibrational assignment and for predicting new vibrational frequencies. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis, spectroscopic and biological activities studies of acyclic and macrocyclic mono and binuclear metal complexes containing a hard-soft Schiff base

NASA Astrophysics Data System (ADS)

Abou-Hussein, Azza A. A.; Linert, Wolfgang

Mono- and bi-nuclear acyclic and macrocyclic complexes with hard-soft Schiff base, H2L, ligand derived from the reaction of 4,6-diacetylresorcinol and thiocabohydrazide, in the molar ratio 1:2 have been prepared. The H2L ligand reacts with Co(II), Ni(II), Cu(II), Zn(II), Mn(II) and UO2(VI) nitrates, VO(IV) sulfate and Ru(III) chloride to get acyclic binuclear complexes except for VO(IV) and Ru(III) which gave acyclic mono-nuclear complexes. Reaction of the acyclic mono-nuclear VO(IV) and Ru(III) complexes with 4,6-diacetylresorcinol afforded the corresponding macrocyclic mono-nuclear VO(IV) and Ru(IIII) complexes. Template reactions of the 4,6-diacetylresorcinol and thiocarbohydrazide with either VO(IV) or Ru(III) salts afforded the macrocyclic binuclear VO(IV) and Ru(III) complexes. The Schiff base, H2L, ligand acts as dibasic with two NSO-tridentate sites and can coordinate with two metal ions to form binuclear complexes after the deprotonation of the hydrogen atoms of the phenolic groups in all the complexes, except in the case of the acyclic mononuclear Ru(III) and VO(IV) complexes, where the Schiff base behaves as neutral tetradentate chelate with N2S2 donor atoms. The ligands and the metal complexes were characterized by elemental analysis, IR, UV-vis 1H-NMR, thermal gravimetric analysis (TGA) and ESR, as well as the measurements of conductivity and magnetic moments at room temperature. Electronic spectra and magnetic moments of the complexes indicate the geometries of the metal centers are either tetrahedral, square planar or octahedral. Kinetic and thermodynamic parameters were calculated using Coats-Redfern equation, for the different thermal decomposition steps of the complexes. The ligands and the metal complexes were screened for their antimicrobial activity against Staphylococcus aureus as Gram-positive bacteria, and Pseudomonas fluorescens as Gram-negative bacteria in addition to Fusarium oxysporum fungus. Most of the complexes exhibit mild

Synthesis, spectroscopic and biological activities studies of acyclic and macrocyclic mono and binuclear metal complexes containing a hard-soft Schiff base.

PubMed

Abou-Hussein, Azza A A; Linert, Wolfgang

2012-09-01

Mono- and bi-nuclear acyclic and macrocyclic complexes with hard-soft Schiff base, H(2)L, ligand derived from the reaction of 4,6-diacetylresorcinol and thiocabohydrazide, in the molar ratio 1:2 have been prepared. The H(2)L ligand reacts with Co(II), Ni(II), Cu(II), Zn(II), Mn(II) and UO(2)(VI) nitrates, VO(IV) sulfate and Ru(III) chloride to get acyclic binuclear complexes except for VO(IV) and Ru(III) which gave acyclic mono-nuclear complexes. Reaction of the acyclic mono-nuclear VO(IV) and Ru(III) complexes with 4,6-diacetylresorcinol afforded the corresponding macrocyclic mono-nuclear VO(IV) and Ru(IIII) complexes. Template reactions of the 4,6-diacetylresorcinol and thiocarbohydrazide with either VO(IV) or Ru(III) salts afforded the macrocyclic binuclear VO(IV) and Ru(III) complexes. The Schiff base, H(2)L, ligand acts as dibasic with two NSO-tridentate sites and can coordinate with two metal ions to form binuclear complexes after the deprotonation of the hydrogen atoms of the phenolic groups in all the complexes, except in the case of the acyclic mononuclear Ru(III) and VO(IV) complexes, where the Schiff base behaves as neutral tetradentate chelate with N(2)S(2) donor atoms. The ligands and the metal complexes were characterized by elemental analysis, IR, UV-vis (1)H-NMR, thermal gravimetric analysis (TGA) and ESR, as well as the measurements of conductivity and magnetic moments at room temperature. Electronic spectra and magnetic moments of the complexes indicate the geometries of the metal centers are either tetrahedral, square planar or octahedral. Kinetic and thermodynamic parameters were calculated using Coats-Redfern equation, for the different thermal decomposition steps of the complexes. The ligands and the metal complexes were screened for their antimicrobial activity against Staphylococcus aureus as Gram-positive bacteria, and Pseudomonas fluorescens as Gram-negative bacteria in addition to Fusarium oxysporum fungus. Most of the complexes exhibit

A novel signal transduction protein: Combination of solute binding and tandem PAS-like sensor domains in one polypeptide chain

DOE PAGES

Wu, R.; Wilton, R.; Cuff, M. E.; ...

2017-02-07

The tandem Per-Arnt-Sim (PAS) like sensors are commonly found in signal transduction proteins. The periplasmic solute binding protein (SBP) domains are found ubiquitously and are generally involved in solute transport. These domains are widely observed as parts of separate proteins but not within the same polypeptide chain. We report the structural and biochemical characterization of the extracellular ligand-binding receptor, Dret_0059 from Desulfohalobium retbaense DSM 5692, an organism isolated from the Retba salt lake in Senegal. The structure of Dret_0059 consists of a novel combination of SBP and TPAS sensor domains. The N-terminal region forms an SBP domain and the C-terminalmore » region folds into a tandem PAS-like domain structure. A ketoleucine moiety is bound to the SBP, whereas a cytosine molecule is bound in the distal PAS domain of the TPAS. The differential scanning flourimetry studies in solution support the ligands observed in the crystal structure. There are only two other proteins with this structural architecture in the non-redundant sequence data base and we predict that they too bind the same substrates. There is significant interaction between the SBP and TPAS domains, and it is quite conceivable that the binding of one ligand will have an effect on the binding of the other. Our attempts to remove the ligands bound to the protein during expression were not successful, therefore, it is not clear what the relative affects are. The genomic context of this receptor does not contain any protein components expected for transport function, hence, we suggest that Dret_0059 is likely involved in signal transduction and not in solute transport.« less

Design, spectral characterization, thermal, DFT studies and anticancer cell line activities of Co(II), Ni(II) and Cu(II) complexes of Schiff bases derived from 4-amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol.

PubMed

Tyagi, Prateek; Chandra, Sulekh; Saraswat, B S; Yadav, Deepak

2015-06-15

A series of two biologically active Schiff base ligands L(1), L(2) have been synthesized in equimolar reaction of 4-amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol with thiophene-2-carbaldehyde and furan-2-carbaldehyde. The synthesized Schiff bases were used for complexation with different metal ions like Co(II), Ni(II) and Cu(II) by using a molar ratio of ligand: metal as 1:1 and 2:1. The characterization of Schiff bases and metal complexes was done by (1)H NMR, UV-Vis, TGA, IR, mass spectrometry and molar conductivity studies. The in DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. On the basis of the spectral studies an octahedral geometry has been assigned for Co(II), Ni(II) and Cu(II) complexes. The effect of these complexes on proliferation of human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (Hep-G2) were studied and compared with those of free ligand. The anticancer cell line results reveal that all metal complexes show moderate to significant % cytotoxicity on cell line HepG2 and MCF-7. Copyright © 2015 Elsevier B.V. All rights reserved.

Your Way to a Better Theory of Mind: A Healthy Diet Relates to Better Faux Pas Recognition in Older Adults.

PubMed

Ruffman, Ted; Zhang, Julie; Taumoepeau, Mele; Skeaff, Sheila

2016-01-01

Aging is characterized by a well-documented worsening of general cognition, and also a decline in social understanding such as the ability to recognize emotions or detect socially inappropriate behavior (faux pas). Several studies have demonstrated that lifestyle factors (diet, exercise, social integration, smoking) tend to offset general cognitive decline, and we examined whether they also help to offset age-related declines in social cognition. There were 56 participants aged 60 years or over. General cognition was measured using a matrices task and the Mini-Mental State Examination (MMSE). Emotion recognition was measured by the matching of faces to emotion sounds and bodies to sounds. Faux pas recognition was measured by 16 videos, examining participants' ability to differentiate appropriate and inappropriate social behavior. Diet, exercise, social integration, and smoking habits were measured via questionnaires. For general cognition, diet, pr = .32, p < .02, smoking, pr = -.32, p = .02, and education, pr = .48, p < .001, explained unique variance in matrices performance. For social cognition, even after accounting for participants' education, age, exercise habits, smoking, and social integration, a healthy diet explained independent variance in the ability to identify appropriate social behavior, pr = .29, p = .04. We replicated previous research in finding that lifestyle factors were related to fluid intelligence. In addition, we obtained the novel finding that a healthy diet is associated with better recognition of faux pas in older adults, likely acting through facilitation of brain health, and providing initial support for a means of enhancing social functioning and well-being in old age.

Spectroscopic investigation and luminescent properties of Schiff base metal complex for OLED

NASA Astrophysics Data System (ADS)

Gondia, N. K.; Priya, J.; Sharma, S. K.

2018-05-01

Organic light emitting diode (OLED) display technology has demonstrated high efficiency and brightness, is leading to a strong commercial interest. One of the remaining problems with the OLED technology is efficiency and colour saturation. The efficiency of OLED devices can be improved by doping the host organic layer with a suitable phosphorescent material in the emissive layer. We have synthesized a Schiff base zinc metal complex for OLEDs applications. Metal complex was characterized by FTIR, HNMR technique. PL emission spectra were recorded by keeping excitation wavelength fixed at 240 nm. A strong intense emission peak was observed at 410 nm. CIE chromaticity colour coordinates were observed at x =0.239 & y = 0.159. HOMO/LUMO energy gap were found to be -0.223 and -0.067 respectively for prepared zinc metal complex. It could be considered as a good light emitting phosphor material for possible application as emissive layer in OLEDs.

Green synthesis of nano sized transition metal complexes containing heterocyclic Schiff base: Structural and morphology characterization and bioactivity study

NASA Astrophysics Data System (ADS)

Jawoor, Shailaja S.; Patil, Sangamesh A.; Kumbar, Mahantesh; Ramawadgi, Prashant B.

2018-07-01

In the current involvement of our research work in coordination chemistry, novel transition metal complexes were synthesized from regular reflux method and hydrothermal method using Schiff base prepared via condensation of ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate with 8-carbaldehyde-7-hydroxy-4-methylcoumarin. All the synthesized compounds were interpreted using different analytical, physicochemical and spectral methods such as magnetic moment measurement, FT-IR, 1H and 13C NMR, GCMS/ESI-MS, UV/Vis spectroscopy and TGA. The size and morphology of the nano metal complexes were determined using atomic force microscope (AFM), field emission scanning electron spectroscopy (FE-SEM) and X-ray powder diffraction (PXRD). The non-electrolytic nature of the metal complexes was confirmed by molar conductance studies. The obtained FT-IR data supports the binding of metal ion to Schiff base. Elemental analysis study suggests [ML2(H2O)2] stoichiometry, here M = Co(II), Ni(II) and Cu(II), L = deprotonated ligand. Electronic spectral results reveal six-coordinated geometry for the synthesized metal complexes. All the tested compounds show good DNA cleavage (Calf Thymus DNA) and in vitro anticancer activity (PA-I cell line), the activity results for the tested compounds are prominent and compound 9 exhibited a little enhanced activity than the other tested compounds.

Mesoporous silica nanoparticles supported copper(II) and nickel(II) Schiff base complexes: Synthesis, characterization, antibacterial activity and enzyme immobilization

NASA Astrophysics Data System (ADS)

Tahmasbi, Leila; Sedaghat, Tahereh; Motamedi, Hossein; Kooti, Mohammad

2018-02-01

Mesoporous silica nanoparticles (MSNs) were prepared by sol-gel method and functionalized with 3-aminopropyltriethoxysilane. Schiff base grafted mesoporous silica nanoparticle was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and amine-functionalized MSNs. The latter material was then treated with Cu(II) and Ni(II) salts separately to obtain copper and nickel complexes anchored mesoporous composites. The newly prepared hybrid organic-inorganic nanocomposites have been characterized by several techniques such as FT-IR, LA-XRD, FE-SEM, TEM, EDS, BET and TGA. The results showed all samples have MCM-41 type ordered mesoporous structure and functionalization occurs mainly inside the mesopore channel. The presence of all elements in synthesized nanocomposites and the coordination of Schiff base via imine nitrogen and phenolate oxygen were confirmed. MSNs and all functionalized MSNs have uniform spherical nanoparticles with a mean diameter less than 100 nm. The as-synthesized mesoporous nanocomposites were investigated for antibacterial activity against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria, as carrier for gentamicin and also for immobilization of DNase, coagulase and amylase enzymes. MSN-SB-Ni indicated bacteriocidal effect against S.aureus and all compounds were found to be good carrier for gentamicin. Results of enzyme immobilization for DNase and coagulase and α-amylase revealed that supported metal complexes efficiently immobilized enzymes.

A novel Schiff base derivative: Synthesis, two-photon absorption properties and application for bioimaging

NASA Astrophysics Data System (ADS)

Wang, Hui; Fang, Bin; Kong, Lin; Li, Xiangzi; Feng, Zhijun; Wu, Yunjun; Uvdal, Kajsa; Hu, Zhangjun

2018-06-01

A novel donor-π-acceptor-π-donor type (D-π-A-π-D‧) Schiff base derivative (L) has been designed and synthesized. The structure of L is confirmed by single-crystal X-ray diffraction analysis as well. The photophysical properties of compound L were comprehensively investigated by using both experimental and theoretical methods. The results indicate that L exhibits large Stokes shift and moderate two-photon action (2PA) cross-section in the near infrared (NIR) region. Furthermore, the confocal microscopy imaging study demonstrates that compound L could penetrate into cells and target the cellular mitochondria compartment. Due to its low cytotoxicity, compound L provides a promising tool for directly lighting up the mitochondria compartment in living HepG2 cells.

Hepatic gluconeogenesis is enhanced by phosphatidic acid which remains uninhibited by insulin in lipodystrophic Agpat2-/- mice.

PubMed

Sankella, Shireesha; Garg, Abhimanyu; Horton, Jay D; Agarwal, Anil K

2014-02-21

In this study we examined the role of phosphatidic acid (PA) in hepatic glucose production (HGP) and development of hepatic insulin resistance in mice that lack 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2). Liver lysophosphatidic acid and PA levels were increased ∼2- and ∼5-fold, respectively, in male Agpat2(-/-) mice compared with wild type mice. In the absence of AGPAT2, the liver can synthesize PAs by activating diacylglycerol kinase or phospholipase D, both of which were elevated in the livers of Agpat2(-/-) mice. We found that PAs C16:0/18:1 and C18:1/20:4 enhanced HGP in primary WT hepatocytes, an effect that was further enhanced in primary hepatocytes from Agpat2(-/-) mice. Lysophosphatidic acids C16:0 and C18:1 failed to increase HGP in primary hepatocytes. The activation of HGP was accompanied by an up-regulation of the key gluconeogenic enzymes glucose-6-phosphatase and phosphoenolpyruvate carboxykinase. This activation was suppressed by insulin in the WT primary hepatocytes but not in the Agpat2(-/-) primary hepatocytes. Thus, the lack of normal insulin signaling in Agpat2(-/-) livers allows unrestricted PA-induced gluconeogenesis significantly contributing to the development of hyperglycemia in these mice.

Alpinia oxyphylla Miquel fruit extract activates MAPK-mediated signaling of PAs and MMP2/9 to induce Schwann cell migration and nerve regeneration.

PubMed

Chang, Yung-Ming; Ye, Chi-Xin; Ho, Tsung-Jung; Tsai, Te-Neng; Chiu, Ping-Ling; Tsai, Chin-Chuan; Lin, Yueh-Min; Kuo, Chia-Hua; Tsai, Fuu-Jen; Tsai, Chang-Hai; Huang, Chih-Yang

2014-05-01

This study investigates the molecular mechanisms by which Alpiniae oxyphyllae fructus (AOF) promotes neuron regeneration. A piece of silicone rubber was guided across a 15 mm gap in the sciatic nerve of a rat. This nerve gap was then filled with different concentrations of AOF extract (0-200 mg/ml). We investigated the role of MAPK (ERK1/2, JNK and p38) pathways for AOF-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in RSC96 Schwann cells. The results showed that AOF increased the expressions of uPA, tPA, MMP-9, and MAPKs in vivo. In vitro, our results show that treatment with AOF extract induces ERK1/2, JNK, and p38 phosphorylation to activate the downstream PAs and MMPs signaling expression. AOF-stimulated ERK1/2, JNK, and p38 phosphorylation attenuated by individual pretreatment with siRNAs or inhibitors (U0126, SP600125 and SB203580), resulting in migration and uPA-related signal pathway inhibition. Taken together our data suggests the MAPKs (ERK1/2, JNK and p38), PAs (uPA, tPA), MMP (MMP2, MMP9) regenerative and migration signaling pathway of Schwann cells regulated by AOF extract might play a major role in Schwann cell migration and damaged peripheral nerve regeneration.

[French translations and adaptations of questionnaires of magical thinking (MIS, Eckblad and Chapman, 1983) and perception disorders (PAS, Chapman et al., 1978)].

PubMed

Dumas, P; Saoud, M; Gutknecht, C; Dalery, J; d'Amato, T

1999-01-01

Meehl used the term "schizotype" to refer to individuals who possess an underlying vulnerability for schizophrenia. Because of the extremely varying degrees of the schizotype's clinical expression, he recommended assessing schizotypic signs through objective measures rather than clinical judgement. In this way, Chapman et al. have developed symptom-oriented scales based on Meehl's manual, such as the Social Anhedonia (SA) and Physical Anhedonia (PhA) Scales, the Magical Ideation Scale (MIS), the Perceptual Aberration Scale (PAS) and the Impulsive Nonconformity Scale (IN). Whereas Chapman's scales of psychosis proneness are the most internationally used instruments for the assessment of schizotypy, some of them, such as MIS and PAS, were still not available in French. Therefore, the first aim of this report was to offer French translations of the Magical Ideation and the Perceptual Aberration Scales; the agreement of the original authors were obtained for both translated versions and their back translations. The second aim of our study was to establish French norms for each of these scales. The preliminary norms presented here [MIS: 19/30 (for females) and 20/30 (for males); PAS: 18/35 (for both genders)] were obtained by administering both scales to a sample of 134 French students. They are very close to those found by Chapman et al. for University of Wisconsin undergraduate students. We will confirm them with a larger sample of French students.

Mutational Analysis of a Role for Salicylic Acid in Iron Metabolism of Mycobacterium smegmatis

PubMed Central

Adilakshmi, Tadepalli; Ayling, Peter D.; Ratledge, Colin

2000-01-01

The role of salicylic acid in iron metabolism was examined in two wild-type strains (mc2155 and NCIMB 8548) and three mutant strains (mc21292 [lacking exochelin], SM3 [lacking iron-dependent repressor protein IdeR] and S99 [a salicylate-requiring auxotroph derived in this study]) of Mycobacterium smegmatis. Synthesis of salicylate in SM3 was derepressed even in the presence of iron, as was synthesis of the siderophores exochelin, mycobactin, and carboxymycobactin. S99 was dependent on salicylate for growth and failed to grow with the three ferrisiderophores, suggesting that salicylate fulfills an additional function(s) other than being a precursor of mycobactin and carboxymycobactin. Salicylic acid at 100 μg/ml repressed the formation of a 29-kDa cell envelope protein (putative exochelin receptor protein) in S99 grown both iron deficiently and iron sufficiently. In contrast, synthesis of this protein was affected only under iron-limited conditions in the parent strain, mc2155, and remained unaltered in SM3, suggesting an interaction between the IdeR protein and salicylate. Thus, salicylate may also function as a signal molecule for recognition of cellular iron status. Growth of all strains and mutants with p-aminosalicylate (PAS) at 100 μg/ml increased salicylate accumulation between three- and eightfold under both iron-limited and iron-sufficient growth conditions and decreased mycobactin accumulation by 40 to 80% but increased carboxymycobactin accumulation by 50 to 55%. Thus, although PAS inhibited salicylate conversion to mycobactin, presumptively by blocking salicylate AMP kinase, PAS also interferes with the additional functions of salicylate, as its effect was heightened in S99 when the salicylate concentration was minimal. PMID:10629169

Impact of proton transfer phenomena on the electronic structure of model Schiff bases: an AIM/NBO/ELF study.

PubMed

Panek, Jarosław J; Filarowski, Aleksander; Jezierska-Mazzarello, Aneta

2013-10-21

Understanding of the electronic structure evolution due to a proton dynamics is a key issue in biochemistry and material science. This paper reports on density functional theory calculations of Schiff bases containing short, strong intramolecular hydrogen bonds where the bridged proton is located: (i) at the donor site, (ii) strongly delocalized, and (iii) at the acceptor site. The mobility of the bridged proton and its influence on the molecular structure and properties of the chosen Schiff base derivatives have been investigated on the basis of Atoms in Molecules, Natural Bond Orbitals, and Electron Localization Function theories. It has been observed that the extent of the bridged proton delocalization is strongly modified by the steric and inductive effects present in the studied compounds introduced by various substituents. It has been shown that: (i) potential energy profiles for the proton motion are extremely dependent on the substitution of the aromatic ring, (ii) the topology of the free electron pairs present at the donor∕acceptor site, as well as their electron populations, are affected qualitatively by the bridged proton position, (iii) the distortion of the molecular structure due to the bridged proton dynamics includes the atomic charge fluctuations, which are in some cases non-monotonic, and (iv) topology of the ELF recognizes events of proton detachment from the donor and attachment to the acceptor. The quantitative and qualitative results shed light onto molecular consequences of the proton transfer phenomena.

Heterobimetallic transition metal/rare earth metal bifunctional catalysis: a Cu/Sm/Schiff base complex for syn-selective catalytic asymmetric nitro-Mannich reaction.

PubMed

Handa, Shinya; Gnanadesikan, Vijay; Matsunaga, Shigeki; Shibasaki, Masakatsu

2010-04-07

The full details of a catalytic asymmetric syn-selective nitro-Mannich reaction promoted by heterobimetallic Cu/Sm/dinucleating Schiff base complexes are described, demonstrating the effectiveness of the heterobimetallic transition metal/rare earth metal bifunctional catalysis. The first-generation system prepared from Cu(OAc)(2)/Sm(O-iPr)(3)/Schiff base 1a = 1:1:1 with an achiral phenol additive was partially successful for achieving the syn-selective catalytic asymmetric nitro-Mannich reaction. The substrate scope and limitations of the first-generation system remained problematic. After mechanistic studies on the catalyst prepared from Sm(O-iPr)(3), we reoptimized the catalyst preparation method, and a catalyst derived from Sm(5)O(O-iPr)(13) showed broader substrate generality as well as higher reactivity and stereoselectivity compared to Sm(O-iPr)(3). The optimal system with Sm(5)O(O-iPr)(13) was applicable to various aromatic, heteroaromatic, and isomerizable aliphatic N-Boc imines, giving products in 66-99% ee and syn/anti = >20:1-13:1. Catalytic asymmetric synthesis of nemonapride is also demonstrated using the catalyst derived from Sm(5)O(O-iPr)(13).

Synthesis, spectral characterization, molecular modeling, biological activity and potentiometric studies of 4-amino-5-mercapto-3-methyl-S-triazole Schiff's base complexes

NASA Astrophysics Data System (ADS)

Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Alharbi, Suliman A.

2015-03-01

The Schiff's base derived from condensation of s-triazole (4-amino-5-mercapto-3-methyl-S-triazole) with pyridine-2-aldehyde and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR, mass), magnetic moment and thermal measurements. The IR spectral data suggest that the ligand coordinate in a tridentate manner (SNN) via the one thiol (SH), one pyridine ring and the azomethine (Cdbnd N) groups. The data show that the complexes have composition of ML2 type. The activation of thermodynamic parameters are calculated using Coats-Redfern, Horowitz-Metzger (HM), and Piloyan-Novikova (PN). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations and ligand field parameters. Protonation constants of Schiff base and stability constants of their binary metal complexes have been determined potentiometrically in 50% DMSO-water media at 25 °C and ionic strength 0.10 M potassium nitrate. The biological activity of these compounds against various fungi has been investigated.

Oestrus synchronization treatment induces histomorphological changes on the uterine tube epithelium of the gilt.

PubMed

Juárez-Mosqueda, M L; Anzaldúa Arce, S R; Palma Lara, I; García Dalmán, C; Cornejo Cortés, M A; Córdova Izquierdo, A; Villaseñor Gaona, H; Trujillo Ortega, M E

2015-12-01

The aim of this study was to determine the histomorphological changes that occurred in response to two treatments for oestrus synchronization in three different regions of the gilt's uterine tubes epithelium: the ampulla (AMP), ampulla-isthmic junction (AIJ) and isthmus (IST). Nine prepuberal gilts were divided into three groups (n = 3): (1) eCG 400 IU and hCG 200 IU (eCG/hCG), (2) progesterone agonist (P4) and (3) control group. The number of secretory cells (stained with periodic acid-Schiff reaction or PAS-positive cells) decreased in the AMP in the P4 treated group when compared to the control group, whereas, no difference was observed in the number of PAS-negative cells in the AMP of the three groups. A significant decrease in the number of PAS-positive cells was observed in the AIJ and IST of the P4 treated group when compared to the eCG/hCG and control groups. An increase in the number of PAS-negative cells was observed in the AIJ and IST in the P4 treated group. The epithelium height in the AMP and AIJ was increased in the eCG/hCG group when compared to the control and P4 groups. In this last group, we observed a reduced height compared with the other two groups for the AIJ. In the IST, there were no significant changes in the epithelium height of the control or the other two groups (eCG/hCG and P4). The epithelial cells of the P4 treated group had the least amount of cytoplasmic granules and the lowest intensity of PAS staining in the AMP, AIJ and IST. Animals treated with eCG/hCG showed an intermediate number of cytoplasmic granules and intensity in all regions evaluated. These data show that P4 treatment for synchronization induces a significant (P < 0.001) decrease of PAS-positive cells and staining intensity of cytoplasmic granules in the different regions studied and an increased number of PAS-negative cells in the AIJ and IST epithelium. Moreover, eCG/hCG treatment increased the height of the epithelium in the AMP and AIJ, while in this last

Comparison between histochemical and immunohistochemical methods for diagnosis of sporotrichosis.

PubMed Central

Marques, M E; Coelho, K I; Sotto, M N; Bacchi, C E

1992-01-01

AIMS: To compare the efficacy of histochemical and immunohistochemical methods in detecting forms of Sporothrix schenckii in tissue. METHODS: Thirty five cutaneous biopsy specimens from 27 patients with sporotrichosis were stained by histochemical haematoxylin and eosin, periodic acid Schiff, and Gomori's methenamine silver methods and an immunohistochemical (avidin-biotin complex immunoperoxidase) (ABC) technique associated with a newly produced rabbit polyclonal antibody anti-Sporothrix schenckii. RESULTS: A total of 29 (83%) cases were positive by the ABC method used in association with anti-Sporothrix schenckii rabbit polyclonal antibodies. Histochemical methods, using silver staining, periodic acid Schiff, and conventional haematoxylin and eosin detected 37%, 23%, and 23% of forms of S schenckii, respectively. The ABC technique was significantly more reliable than periodic acid Schiff and silver staining techniques. CONCLUSIONS: It is concluded that immunostaining is an easy and rapid method which can efficiently increase the accuracy of the diagnosis of sporotrichosis in human tissue. Images PMID:1479036

New solitary wave solutions to the (2+1)-dimensional Calogero-Bogoyavlenskii-Schiff and the Kadomtsev-Petviashvili hierarchy equations

NASA Astrophysics Data System (ADS)

Baskonus, Haci Mehmet; Sulaiman, Tukur Abdulkadir; Bulut, Hasan

2017-10-01

In this paper, with the help of Wolfram Mathematica 9 we employ the powerful sine-Gordon expansion method in investigating the solution structures of the two well known nonlinear evolution equations, namely; Calogero-Bogoyavlenskii-Schiff and Kadomtsev-Petviashvili hierarchy equations. We obtain new solutions with complex, hyperbolic and trigonometric function structures. All the obtained solutions in this paper verified their corresponding equations. We also plot the three- and two-dimensional graphics of all the obtained solutions in this paper by using the same program in Wolfram Mathematica 9. We finally submit a comprehensive conclusion.

Synthesis, characterization and crystal structure of (2RS,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid

NASA Astrophysics Data System (ADS)

Muche, Simon; Müller, Matthias; Hołyńska, Małgorzata

2018-03-01

The condensation reaction of ortho-vanillin and L-cysteine leads to formation of a racemic mixture of (2RS,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid and not, as reported in the available literature, to a Schiff base. The racemic mixture was fully characterized by 1D and 2D NMR techniques, ESI-MS and X-ray diffraction. Addition of ZnCl2 led to formation of crystals in form of colorless needles, suitable for X-ray diffraction studies. The measured crystals were identified as the diastereomer (2R,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid 1. The bulk material is racemic. Thiazolidine exists as zwitterion in solid state, as indicated by the crystal structure.

Catalytic asymmetric ring-opening of meso-aziridines with malonates under heterodinuclear rare earth metal Schiff base catalysis.

PubMed

Xu, Yingjie; Lin, Luqing; Kanai, Motomu; Matsunaga, Shigeki; Shibasaki, Masakatsu

2011-04-20

Catalytic asymmetric ring-opening of meso-aziridines with malonates is described. The combined use of two rare earth metal sources with different properties promoted the desired ring-opening reaction. A 1:1:1 mixture of a heterobimetallic La(O-iPr)(3)/Yb(OTf)(3)/Schiff base 1a (0.25-10 mol %) efficiently promoted the reaction of five-, six-, and seven-membered ring cyclic meso-aziridines as well as acyclic meso-aziridines with dimethyl, diethyl, and dibenzyl malonates, giving chiral cyclic and acyclic γ-amino esters in 99-63% yield and >99.5-97% ee.

Step-scan differential Fourier transform infrared photoacoustic spectroscopy (DFTIR-PAS): a spectral deconvolution method for weak absorber detection in the presence of strongly overlapping background absorptions.

PubMed

Liu, Lixian; Mandelis, Andreas; Huan, Huiting; Michaelian, Kirk H

2017-04-01

The determination of small absorption coefficients of trace gases in the atmosphere constitutes a challenge for analytical air contaminant measurements, especially in the presence of strongly absorbing backgrounds. A step-scan differential Fourier transform infrared photoacoustic spectroscopy (DFTIR-PAS) method was developed to suppress the coherent external noise and spurious photoacoustic (PA) signals caused by strongly absorbing backgrounds. The infrared absorption spectra of acetylene (C₂H₂) and local air were used to verify the performance of the step-scan DFTIR-PAS method. A linear amplitude response to C₂H₂ concentrations from 100 to 5000 ppmv was observed, leading to a theoretical detection limit of 5 ppmv. The differential mode was capable of eliminating the coherent noise and dominant background gas signals, thereby revealing the presence of the otherwise hidden C₂H₂ weak absorption. Thus, the step-scan DFTIR-PAS modality was demonstrated to be an effective approach for monitoring weakly absorbing gases with absorption bands overlapped by strongly absorbing background species.